阅读说明：本技术 一种商用车轮毂轴承润滑脂及其制备方法 (Commercial vehicle wheel hub bearing lubricating grease and preparation method thereof ) 是由 许扬 王彦冬 闫瑾 徐小鹏 王清国 桃春生 汪玉瑄 于 2019-07-16 设计创作，主要内容包括：本发明公开了一种商用车轮毂轴承润滑脂及其制备方法,属于商用车轮毂轴承润滑脂技术领域,本发明的目的是提高润滑脂高温稳定性、胶体安定性,降低润滑脂分油量,提高润滑脂极压性、抗剪切性,降低润滑脂稠度变化,减少润滑脂甩脂风险,本发明中复合聚脲稠化剂、复合磺酸钙稠化剂与复合锂稠化剂通过一体化合成方法复合,以明显提高润滑脂高温稳定性、胶体安定性,降低润滑脂分油量,延长高温轴承寿命,减少润滑脂漏油风险；提高润滑脂极压性、抗剪切性,降低润滑脂稠度变化,减少润滑脂甩脂风险。合成粘附剂与天然粘附剂的组合物起到协同作用,明显提高润滑脂剪切安定性,降低润滑脂稠度变化并很好地粘附在摩擦副表面,减少润滑脂甩脂风险。(The invention discloses a commercial vehicle hub bearing lubricating grease and a preparation method thereof, belonging to the technical field of commercial vehicle hub bearing lubricating grease, aiming at improving the high-temperature stability and the colloid stability of the lubricating grease, reducing the oil distribution amount of the lubricating grease, improving the extreme pressure property and the shearing resistance of the lubricating grease, reducing the consistency change of the lubricating grease and reducing the grease throwing risk of the lubricating grease; the extreme pressure property and the shearing resistance of the lubricating grease are improved, the consistency change of the lubricating grease is reduced, and the risk of throwing the lubricating grease is reduced. The composition of the synthetic adhesive and the natural adhesive has a synergistic effect, the shear stability of the lubricating grease is obviously improved, the consistency change of the lubricating grease is reduced, the lubricating grease is well adhered to the surface of a friction pair, and the risk of grease throwing of the lubricating grease is reduced.)

1. A commercial vehicle wheel hub bearing grease is characterized by comprising the following raw material components by weight: 81-88 wt% of base oil, 10-15 wt% of composite thickening agent, 1.2-1.8 wt% of composite adhesive, 0.5-0.9 wt% of antioxidant, 0.5-0.9 wt% of extreme pressure antiwear agent and 0.001-0.005 wt% of antirust agent;

the base oil is a group II base oil, a group III base oil or a combination of the two;

the composite thickening agent consists of a composite polyurea thickening agent, a composite calcium sulfonate thickening agent and a composite lithium thickening agent in a weight ratio of (2:1:7) - (3:2: 5);

the composite polyurea thickening agent is prepared by compounding 1.02-2.30 wt% of diisocyanate, 0.42-0.95 wt% of organic amine, 0.24-0.54 wt% of carboxyl source and 0.08-0.18 wt% of alkali metal;

wherein, the diisocyanate is diphenylmethane-4, 4-diisocyanate or toluene diisocyanate; the organic amine is one or the combination of more of cyclohexylamine, p-toluidine, decaamine, hexamethylene diamine and p-phenylenediamine; the carboxyl source is caprolactam or ethyl p-aminobenzoate; the alkali metal is sodium hydroxide or lithium hydroxide;

the compound calcium sulfonate thickening agent is prepared by compounding 0.77-2.31 wt% of high-alkalinity calcium sulfonate, 0.13-0.39 wt% of transforming agent, 0.06-0.18 wt% of saponification acid and 0.03-0.09 wt% of saponification alkali; wherein the overbased calcium sulfonate is overbased calcium petroleum sulfonate or overbased synthetic calcium sulfonate; the transforming agent is water, acetic acid or methanol; the saponification acid is dodecahydroxy stearic acid, dodecanoic acid, hexadecanoic acid or boric acid; the saponification alkali is calcium hydroxide or calcium carbonate;

the composite lithium thickening agent is prepared by compounding 4.41-6.62 wt% of positive soap, 0.90-1.89 wt% of complexing agent and 0.90-1.90 wt% of lithium hydroxide; wherein the normal soap is dodecahydroxystearic acid or stearic acid; the complexing agent is one or the combination of more of sebacic acid, azelaic acid and boric acid;

the composite adhesive is compounded by a synthetic adhesive and a natural adhesive in a compounding ratio of 1:1, wherein the synthetic adhesive is one or a composition of more of polymethacrylate, polyisobutylene and an ethylene-propylene copolymer, and the natural adhesive is one or two of natural rubber and rosin;

the antioxidant is diphenylamine or 2, 6-di-tert-butyl-p-cresol;

the extreme pressure antiwear agent is zinc dialkyl dithiophosphate;

the antirust agent consists of benzotriazole and dodecenylsuccinic acid.

2. The commercial wheel hub bearing grease of claim 1 wherein the diisocyanate is diphenylmethane-4, 4-diisocyanate.

3. The commercial wheel hub bearing grease of claim 1 wherein the organic amine is a combination of cyclohexylamine and p-toluidine.

4. The commercial wheel hub bearing grease of claim 1 wherein the carboxyl source is caprolactam.

5. The commercial wheel hub bearing grease of claim 1 wherein the alkali metal is lithium hydroxide.

6. The commercial wheel hub bearing grease of claim 1 wherein the overbased calcium sulfonate is overbased calcium petroleum sulfonate.

7. The commercial wheel hub bearing grease of claim 1 wherein the converting agent is water.

8. The commercial wheel hub bearing grease of claim 1 wherein the saponified acid is dodecahydroxystearic acid.

9. The commercial wheel hub bearing grease of claim 1 wherein the saponified base is calcium hydroxide.

10. The commercial wheel hub bearing grease of claim 1 wherein the positive soap is dodecahydroxystearic acid.

11. The commercial wheel hub bearing grease of claim 1 wherein the complexing agent is a combination of sebacic acid and boric acid.

12. A method of preparing the commercial wheel hub bearing grease of claim 1, comprising the steps of:

1) adding 0.77-2.31 wt% of overbased calcium sulfonate and 0.13-0.39 wt% of transforming agent into a reaction kettle, stirring, heating to 90-100 ℃, and stirring for 35 minutes at constant temperature;

2) adding 0.06-0.18 wt% of saponification acid and 0.03-0.09 wt% of saponification alkali, diluting the saponification alkali with 3 times of water to obtain a suspension when the saponification alkali is used, heating to 140-;

3) cooling to 90-100 deg.C, adding base oil and 4.41-6.62 wt% of normal soap, stirring at constant temperature for 35 min;

4) cooling to 83-87 ℃, adding 0.45-0.95 wt% of lithium hydroxide, diluting the lithium hydroxide into an aqueous solution by using 9 times of water when the lithium hydroxide is used, heating to 140-;

5) cooling to 90-100 ℃, adding the base oil, 0.42-0.95 wt% of organic amine and 0.24-0.54 wt% of carboxyl source, and stirring for 35 minutes at constant temperature;

6) cooling to 65-75 ℃, adding 0.24-0.54 wt% of hexamethylene diamine, base oil and 1.02-2.30 wt% of diisocyanate within 40 +/-5 minutes, and stirring at constant temperature for 60-120 minutes;

7) heating to 90-100 ℃, adding 0.90-1.89 wt% of complexing agent, stirring, continuously heating to 140 ℃ and 150 ℃, and stirring at constant temperature for 35 minutes;

8) cooling to 83-87 ℃, completing the addition of 0.57-1.07 wt% of lithium hydroxide within 60 +/-5 minutes, diluting the lithium hydroxide into an aqueous solution by 9 times of water when the lithium hydroxide is used, stirring, heating to 140-240 ℃, stirring at constant temperature for 60 minutes, heating to 220-240 ℃, and stirring at constant temperature for 35 minutes;

9) cooling to 140 ℃ and 150 ℃, adding the base oil, and stirring for 30 minutes at constant temperature;

10) heating to 240 ℃ again, and stirring for 5 minutes at constant temperature;

11) cooling to 190 ℃, adding a composite adhesive (composed of a synthetic adhesive, a natural adhesive and the balance of base oil), continuously cooling to 90-100 ℃, and adding an antioxidant, an extreme pressure antiwear agent and an antirust agent;

12) continuously cooling to 65-75 ℃, grinding and homogenizing.

Technical Field

The invention belongs to the technical field of commercial vehicle wheel hub bearing lubricating grease.

Background

The bearing is divided into an open bearing and a closed bearing according to the sealing condition, and along with the development of the bearing to unitization, the use of the bearing unit based on the closed bearing is increased. Sealed bearings can be lubricated with lubricating oil, but lubricating oil has a high requirement for oil resistance of seals, and grease is still the main lubricating medium for bearings.

Commercial wheel hub bearings are divided into open pairs of bearings and closed bearing units. The closed bearing unit is usually lubricated by using lubricating oil, so that the long service life of the bearing can be realized without maintenance. The open paired bearings cannot be lubricated by lubricating oil, and are usually lubricated by lithium-based lubricating grease or lithium complex lubricating grease, but the lubricating grease is limited by use conditions, so that the problems of oil leakage, grease throwing and the like easily occur, and the long service life and maintenance-free performance of the bearings cannot be realized.

The lubricating grease is subjected to the actions of high temperature, frequent shearing and the like, a space network structure formed by a thickening agent is damaged, a large amount of free oil and adsorbed oil are irreversibly separated out, the consistency is rapidly reduced and softened, the lubricating grease is influenced by a large centrifugal force, the problems of oil leakage and grease throwing of the lubricating grease occur, the corrosion protection and the lubrication protection degree of a bearing are reduced, and the service life of the bearing is influenced.

In order to solve the problems of oil leakage and grease throwing of the hub bearing lubricating grease, a proper method is needed to improve the stability of a lubricating grease densifier under the action of high temperature and high shear, so that the oil distribution amount is controlled within a reasonable range, the adhesion capacity of the lubricating grease on the surface of a bearing friction pair is improved by a proper method, and the risk of throwing the lubricating grease under the action of centrifugal force is reduced. Specifically, a thickener with good thermal stability and strong mechanical stability is required to be adopted during the formula design of the lubricating grease, so that the structural stability of the lubricating grease thickener fiber under the action of high temperature and high shear is maintained; the capability of the lubricating grease for resisting centrifugal force is improved by adding special additives.

Currently, greases of the common thickener type exhibit different high temperature properties. On the dropping point project, the composite calcium sulfonate lubricating grease > the composite lithium lubricating grease > the polyurea lubricating grease > the composite aluminum-based lubricating grease > the lithium-based lubricating grease; on the high-temperature rheological property project, the structure retention capacity of the lubricating grease is reduced along with the temperature rise, the structure retention capacity is stronger and easier to be hardened, the structure retention capacity is that the composite lithium lubricating grease is more than the carbamido lubricating grease (arylamine) and more than the composite aluminum-based lubricating grease is more than the carbamido lubricating grease (long-chain amine) and more than the carbamido lubricating grease (short-chain arylamine) and more than the composite calcium sulfonate lubricating grease at normal temperature, and the structure retention capacity is that the carbamido lubricating grease (arylamine) is more than the carbamido lubricating grease (short-chain arylamine) and more than the carbamido lubricating grease (long-chain amine) and more than the composite aluminum-based lubricating.

Grease adhesion agents, like viscosity index improvers for lubricating oils, on the one hand increase the viscosity of the base oil in the grease and reduce the fluidity of the base oil, and on the other hand increase the "contact angle" of the grease base oil with the solid interface and increase the adhesion of the grease to the solid. Common grease adhesives include Polyisobutylene (PIB), Polymethacrylate (PMA), ethylene-propylene copolymer (OCP).

The preparation method of the lubricating grease is generally divided into a condensation method and a dispersion method, namely, chemical substances forming the thickening agent are added into base oil step by step, and the lubricating grease is produced through the technical processes of heating dissolution, high-temperature esterification (saponification), high-temperature dehydration, cooling homogenization, grinding and the like, wherein the high-temperature esterification (saponification) process is an important step for forming a network structure of the thickening agent, is beneficial to the sufficient association among molecules of the thickening agent, is simple to operate and easy to industrialize, and has higher control requirements on the technical parameters such as preparation temperature, stirring time and the like.

CN 102618368B discloses a lubricating grease for heavy-duty automobile hubs and a preparation method thereof, wherein a composite lithium soap thickener is used as a thickening agent, and borate oil, a compound viscosity index improver, a detergent dispersant, an amine antioxidant, a sulfur-phosphorus antioxidant and a sulfonate antirust agent are added to obtain the hub lubricating grease with heat resistance, adhesion, mechanical stability, water resistance and extreme pressure abrasion resistance. However, the invention only comprises one thickening agent, and the additive is various.

CN 102839041B discloses a composite lithium lubricating grease composition and a preparation method thereof, which takes composite lithium as a thickening agent, and polybutylene or polymethacrylate, an antioxidant, an extreme pressure antiwear agent and an antirust agent are added. The obtained lubricating grease has good adhesion, excellent water resistance and heat resistance, and is suitable for lubricating automobile hub bearings under harsh working conditions. However, the invention only comprises one thickening agent, and the additive is various.

CN 108841430A discloses a composite urea aluminum-based lubricating grease composition and a preparation method thereof, wherein polyurea and composite aluminum are used as thickening agents, antirust agents are added, and the lubricating grease with high-temperature colloid stability, metal adhesion, film forming property and extreme pressure wear resistance is obtained by mixing, and is suitable for being used in high-temperature, heavy-load, humid and other environments. However, the thickening agent disclosed by the invention is high in production cost and is not beneficial to industrial popularization.

CN 1257963C discloses a preparation method of polyurea-lithium based lubricating grease, which comprises preparing a polyurea thickening agent, continuously preparing a lithium based thickening agent in the same reaction kettle, and heating, cooling, homogenizing to obtain lubricating grease with the same technical performance as the mixing method. However, the thickening agent disclosed by the invention is only a lithium-based thickening agent, and the compounding of a composite lithium thickening agent and a polyurea thickening agent is not involved.

CN1414076A discloses a high base number composite calcium sulfonate lubricating grease and a preparation method thereof, wherein a calcium sulfonate thickener is prepared firstly, and then a carbamido thickener is prepared, so that the compounding of calcium sulfonate and the carbamido thickener is realized. However, the thickening agent disclosed by the method has high production cost and is not beneficial to industrial production.

CN104711080B discloses a modified compound calcium sulfonate lubricating grease and a preparation method thereof, wherein high-base-number calcium sulfonate, lithium hydroxide, dodecahydroxy stearic acid and binary acid are used as basic raw materials, and the prepared lubricating grease contains a compound calcium sulfonate thickening agent and a compound lithium thickening agent. However, the thickening agent disclosed by the invention does not contain a composite polyurea thickening agent.

Disclosure of Invention

In order to improve the high-temperature stability and the colloid stability of the lubricating grease, reduce the oil content of the lubricating grease, improve the extreme pressure property and the shearing resistance of the lubricating grease, reduce the consistency change of the lubricating grease and reduce the risk of throwing the lubricating grease, the invention provides the commercial vehicle hub bearing lubricating grease, which adopts the following technical scheme:

the commercial vehicle wheel hub bearing lubricating grease comprises the following raw material components in parts by weight: 81-88 wt% of base oil, 10-15 wt% of composite thickening agent, 1.2-1.8 wt% of composite adhesive, 0.5-0.9 wt% of antioxidant, 0.5-0.9 wt% of extreme pressure antiwear agent and 0.001-0.005 wt% of antirust agent.

The base oil is a group II base oil, a group III base oil or a combination of the two.

The composite thickening agent consists of a composite polyurea thickening agent, a composite calcium sulfonate thickening agent and a composite lithium thickening agent in a weight ratio of (2:1:7) - (3:2: 5).

The composite polyurea thickening agent is prepared by compounding 1.02-2.30 wt% of diisocyanate, 0.42-0.95 wt% of organic amine, 0.24-0.54 wt% of carboxyl source and 0.08-0.18 wt% of alkali metal.

Wherein the diisocyanate is diphenylmethane-4, 4-diisocyanate (MDI) or Toluene Diisocyanate (TDI), preferably diphenylmethane-4, 4-diisocyanate (MDI); the organic amine is one or more of cyclohexylamine, p-toluidine, decaamine, hexamethylenediamine and p-phenylenediamine, preferably a composition of cyclohexylamine and p-toluidine; the carboxyl source is caprolactam or ethyl p-aminobenzoate, and caprolactam is preferred; the alkali metal is sodium hydroxide or lithium hydroxide, preferably lithium hydroxide.

The compound calcium sulfonate thickening agent is prepared by compounding 0.77-2.31 wt% of high-alkalinity calcium sulfonate, 0.13-0.39 wt% of transforming agent, 0.06-0.18 wt% of saponification acid and 0.03-0.09 wt% of saponification alkali. Wherein the overbased calcium sulfonate is overbased calcium petroleum sulfonate or overbased synthetic calcium sulfonate, preferably overbased calcium petroleum sulfonate; the transforming agent is water, acetic acid or methanol, preferably water; the saponification acid is dodecahydroxystearic acid, dodecanoic acid, hexadecanoic acid or boric acid, preferably dodecahydroxystearic acid; the saponification base is calcium hydroxide or calcium carbonate, preferably calcium hydroxide.

The composite lithium thickening agent is prepared by compounding 4.41-6.62 wt% of normal soap, 0.90-1.89 wt% of complexing agent and 0.90-1.90 wt% of lithium hydroxide. Wherein, the normal soap is dodecahydroxystearic acid or stearic acid, preferably dodecahydroxystearic acid; the complexing agent is one or more of sebacic acid, azelaic acid and boric acid, preferably the composition of sebacic acid and boric acid.

The composite adhesive is compounded by a synthetic adhesive and a natural adhesive in a compounding ratio of 1:1, wherein the synthetic adhesive is one or a composition of more of polymethacrylate, polyisobutylene and an ethylene-propylene copolymer, and the natural adhesive is one or two of natural rubber and rosin.

The antioxidant is diphenylamine or 2, 6-di-tert-butyl-p-cresol.

The extreme pressure antiwear agent is zinc dialkyl dithiophosphate.

The antirust agent consists of benzotriazole and dodecenylsuccinic acid.

The invention relates to a preparation method of commercial vehicle wheel hub bearing lubricating grease, which comprises the following steps:

1) adding 0.77-2.31 wt% of overbased calcium sulfonate and 0.13-0.39 wt% of transforming agent into a reaction kettle, stirring, heating to 90-100 ℃, and stirring for 35 minutes at constant temperature;

2) adding 0.06-0.18 wt% of saponification acid and 0.03-0.09 wt% of saponification alkali (diluted by 3 times of water to form suspension when in use), heating to 140-150 ℃, and stirring at constant temperature for 35 minutes;

3) cooling to 90-100 deg.C, adding base oil and 4.41-6.62 wt% of normal soap, stirring at constant temperature for 35 min;

4) cooling to 83-87 deg.C, adding 0.45-0.95 wt% lithium hydroxide (diluted with 9 times of water to obtain water solution when in use), heating to 140 deg.C and 150 deg.C, and stirring at constant temperature for 35 min;

5) cooling to 90-100 ℃, adding the base oil, 0.42-0.95 wt% of organic amine and 0.24-0.54 wt% of carboxyl source, and stirring for 35 minutes at constant temperature;

6) cooling to 65-75 ℃, adding 0.24-0.54 wt% of hexamethylene diamine, base oil and 1.02-2.30 wt% of diisocyanate within 40 +/-5 minutes, and stirring at constant temperature for 60-120 minutes;

7) heating to 90-100 ℃, adding 0.90-1.89 wt% of complexing agent, stirring, continuously heating to 140 ℃ and 150 ℃, and stirring at constant temperature for 35 minutes;

8) cooling to 83-87 ℃, completing the addition of 0.57-1.07 wt% of lithium hydroxide (diluted into aqueous solution by 9 times of water when in use) within 60 +/-5 minutes, stirring, heating to 150 ℃ for 140-;

9) cooling to 140 ℃ and 150 ℃, adding the base oil, and stirring for 30 minutes at constant temperature;

10) heating to 240 ℃ again, and stirring for 5 minutes at constant temperature;

11) cooling to 190 ℃, adding a composite adhesive (composed of a synthetic adhesive, a natural adhesive and the balance of base oil), continuously cooling to 90-100 ℃, and adding an antioxidant, an extreme pressure antiwear agent and an antirust agent;

12) continuously cooling to 65-75 ℃, grinding and homogenizing.

The invention has the beneficial effects that:

1. the composite polyurea thickening agent, the composite calcium sulfonate thickening agent and the composite lithium thickening agent are compounded by an integrated synthesis method, so that the high-temperature stability and the colloid stability of the lubricating grease can be obviously improved, the oil distribution amount of the lubricating grease is reduced, the service life of a high-temperature bearing is prolonged, and the oil leakage risk of the lubricating grease is reduced; the extreme pressure property and the shearing resistance of the lubricating grease are improved, the consistency change of the lubricating grease is reduced, and the risk of throwing the lubricating grease is reduced.

2. The composition of the synthetic adhesive and the natural adhesive has a synergistic effect, the shear stability of the lubricating grease is obviously improved, the consistency change of the lubricating grease is reduced, the lubricating grease is well adhered to the surface of a friction pair, and the risk of grease throwing of the lubricating grease is reduced.

Detailed Description