A grease composition

Abstract

This invention discloses a lubricating grease composition, belonging to the field of lubricating grease technology. The lubricating grease is made from the following raw materials in parts by weight: 20-40 parts base oil, 10-35 parts liquid polybutadiene, 10-30 parts liquid polyisoprene, 10-30 parts liquid styrene-isoprene polymer, 4-15 parts thickener, 0.1-2 parts antioxidant, 0.1-1.5 parts rust inhibitor, and 0.5-3.2 parts extreme pressure anti-wear agent. The lubricating grease of this invention retains the basic properties of lubricating grease while ensuring high viscosity and high adhesion, as well as low-temperature fluidity. Even in a low-temperature environment of -60°C, it can ensure low-temperature start-up, low operating torque, low-temperature pumpability, and fluidity.

Description

Technical Field

[0001] This invention relates to the field of grease technology, and more specifically, to a grease composition. Background Technology

[0002] Lubricating grease is a semi-solid paste-like product used for lubrication, protection, sealing, and damping of mechanical equipment. It is mainly composed of mineral oil, synthetic oil, thickeners, and additives. Lubricating greases used in passenger cars and industrial equipment widely require excellent adhesion properties to better adhere to the surfaces of friction pairs, achieving lubrication, damping, and corrosion protection. However, increased adhesion increases the low-temperature operating resistance of the grease, making low-temperature pumping and filling extremely difficult; there is a contradiction between high adhesion and damping properties and low-temperature performance. Existing high-viscosity polyalphaolefin (PAO), high-viscosity composite esters, high molecular weight polyisobutylene (PIB), and high molecular weight ethylene-propylene copolymer (OCP) polymers, if their kinematic viscosity at 40°C exceeds 1500 mmHg... 2 If the viscosity is low, it will be difficult to flow below -40℃. Therefore, it is essential to develop high-viscosity, high-adhesion greases with excellent low-temperature performance. Summary of the Invention

[0003] The purpose of this invention is to overcome the shortcomings of the prior art and provide a lubricating grease composition.

[0004] To achieve the above objectives, the present invention adopts the following technical solution:

[0005] A grease composition comprising the following raw materials in parts by weight: 20-40 parts base oil, 10-35 parts liquid polybutadiene, 10-30 parts liquid polyisoprene, 10-30 parts liquid styrene-isoprene polymer, 4-15 parts thickener, 0.1-2 parts antioxidant, 0.1-1.5 parts rust inhibitor, and 0.5-3.2 parts extreme pressure anti-wear agent.

[0006] The present invention is further configured such that the thickener is one or more of the following: lithium fatty acid soap, calcium fatty acid soap, compound lithium soap, compound aluminum soap, compound barium soap, compound calcium sulfonate, bentonite, silica, polyurea, and PTFE micro powder.

[0007] The present invention is further configured such that the rust inhibitor is one or more of alkyl naphthalene sulfonate, alkyl sulfonate, naphthenate, fatty acid salt, and castor oil phosphate salt.

[0008] The present invention is further configured such that the antioxidant is a mixture of amine-type antioxidants and phenol-type antioxidants.

[0009] The present invention is further configured such that the extreme pressure anti-wear agent is one or more of octadecyl phosphite, 2-ethane-dithiocarbamate, molybdenum dithiophosphate, zinc dialkyl dithiophosphate, and 2,5-bis(2'-hydroxydodecyl)-1,3,4-thiadiazole.

[0010] The present invention is further configured such that the base oil is one or more of polyalphaolefin synthetic oil, synthetic ester, alkyl naphthalene, polyisobutylene, polyether, and mineral oil.

[0011] The present invention is further configured such that the grease is made from the following raw materials in parts by weight: 29 parts base oil, 20 parts liquid polybutadiene, 20 parts liquid polyisoprene, 20 parts liquid styrene-isoprene polymer, 7 parts thickener, 1 part antioxidant, 1 part rust inhibitor, and 2 parts extreme pressure anti-wear agent.

[0012] The present invention is further configured to mix liquid polybutadiene, liquid polyisoprene, liquid styrene-isoprene polymer, base oil and thickener in proportion and heat to 150-210°C, cool to below 100°C and then add antioxidant, rust inhibitor and extreme pressure anti-wear agent and mix evenly, and then homogenize by homogenizing with a homogenizer, grinder or high-speed dispersion equipment to obtain grease.

[0013] In summary, the present invention has the following beneficial effects:

[0014] This invention uses liquid polybutadiene, liquid polyisoprene, and liquid styrene-isoprene polymer as the main components of the grease. The grease prepared retains the basic properties of grease (lubricity, fluidity, rust prevention, and colloidal stability), while also ensuring high viscosity and high adhesion. Moreover, even at a low temperature of -60°C, it can ensure low starting and running torque, good low-temperature pumpability, and low-temperature fluidity. It is compatible with most current plastics and can withstand more demanding working conditions. Detailed Implementation

[0015] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0016] The lubricating grease composition of this invention is made from the following raw materials in parts by weight: 20-40 parts base oil, 10-35 parts liquid polybutadiene, 10-30 parts liquid polyisoprene, 10-30 parts liquid styrene-isoprene polymer, 4-15 parts thickener, 0.1-2 parts antioxidant, 0.1-1.5 parts rust inhibitor, 0.5-3.2 parts extreme pressure anti-wear agent, and 0-10 parts tea polyphenol palmitate. The liquid polybutadiene, liquid polyisoprene, liquid styrene-isoprene polymer, base oil, and thickener are mixed evenly in proportion and heated to 150-210°C, then cooled to below 100°C. The antioxidant, rust inhibitor, and extreme pressure anti-wear agent are added, with or without tea polyphenol palmitate. The mixture is then homogenized using a homogenizer, grinder, or high-speed dispersion equipment to obtain the lubricating grease.

[0017] The thickener is one or more of the following: lithium fatty acid soap, calcium fatty acid soap, compound lithium soap, compound aluminum soap, compound barium soap, compound calcium sulfonate, bentonite, silica, polyurea, and PTFE micro powder. The rust inhibitor is one or more of the following: alkyl naphthalene sulfonate, alkyl sulfonate, naphthenate, fatty acid salt, and castor oil phosphate salt. The antioxidant is a mixture of amine-type and phenol-type antioxidants. The extreme pressure anti-wear agent is one or more of the following: octadecyl phosphite, 2-ethane-dithiocarbamate, molybdenum dithiophosphate, zinc dialkyl dithiophosphate, and 2,5-bis(2'-hydroxydodecyl)-1,3,4-thiadiazole. The base oil is one or more of the following: polyalphaolefin synthetic oil, synthetic ester (such as dialkyl carbonate), alkyl naphthalene, polyisobutylene, polyether, and mineral oil.

[0018] The grease of this invention ensures high viscosity and high adhesion, while also ensuring low starting and running torque, good low-temperature pumpability and fluidity even in a low-temperature environment of -60°C.

[0019] Example 1

[0020] Prepare the following raw materials in parts by weight: 29 parts base oil PAO6, 20 parts liquid polybutadiene, 20 parts liquid polyisoprene, 20 parts liquid styrene-isoprene polymer, 7 parts thickener lithium dodecyl stearate soap, 1 part antioxidant (0.5 parts antioxidant L135, 0.5 parts diisooctyl diphenylamine), 1 part rust inhibitor (0.4 parts sodium isopropyl naphthalene sulfonate, 0.6 parts castor oil phosphate salt), and 2 parts extreme pressure anti-wear agent 2,5-bis(2'-hydroxydodecyl)-1,3,4-thiadiazole. Mix the liquid polybutadiene, liquid polyisoprene, liquid styrene-isoprene polymer, base oil, and thickener evenly in the specified proportions and heat to 165°C. After cooling to 95°C, add the antioxidant, rust inhibitor, and extreme pressure anti-wear agent, mix evenly, and homogenize using a homogenizer to obtain the grease.

[0021] Comparative Example 1

[0022] The liquid polybutadiene, liquid polyisoprene, and liquid styrene-isoprene polymer in Example 1 were replaced by an equal mass of high-viscosity polyalphaolefin (HC2000), and the grease was prepared according to the method described in Example 1.

[0023] Comparative Example 2

[0024] The liquid polybutadiene, liquid polyisoprene, and liquid styrene-isoprene polymer in Example 1 were replaced by an equal mass of the composite ester (Priolube 3986), and the grease was prepared according to the method described in Example 1.

[0025] Comparative Example 3

[0026] The liquid polybutadiene, liquid polyisoprene, and liquid styrene-isoprene polymer in Example 1 were replaced by polyisobutylene (PIB2400) in equal mass, and the grease was prepared according to the method described in Example 1.

[0027] Comparative Example 4

[0028] The liquid polybutadiene, liquid polyisoprene, and liquid styrene-isoprene polymer in Example 1 were replaced by ethylene propylene copolymer (OCP) in equal mass, and the grease was prepared according to the method described in Example 1.

[0029] The performance of the greases obtained in Example 1 and Comparative Examples 1-4 were tested respectively, and the results are shown in Table 1.

[0030] Table 1

[0031]

[0032]

[0033] Comparative Example 5

[0034] The grease was prepared according to the method in Example 1, except that liquid polybutadiene was not added.

[0035] Comparative Example 6

[0036] The grease was prepared according to the method in Example 1, except that polyisoprene was not added.

[0037] Comparative Example 7

[0038] The grease was prepared according to the method of Example 1, except that no styrene-isoprene polymer was added.

[0039] Comparative Example 8

[0040] The grease was prepared according to the method of Example 1, except that polybutadiene and liquid polyisoprene were not added.

[0041] Comparative Example 9

[0042] The grease was prepared according to the method of Example 1, except that polybutadiene and liquid styrene-isoprene polymer were not added.

[0043] Comparative Example 10

[0044] The grease was prepared according to the method of Example 1, except that liquid styrene-isoprene polymer was not added.

[0045] Tests revealed that the kinematic viscosity at -40℃ of the greases prepared in Comparative Examples 5-10 was higher than that in Example 1 (an increase of 13.7-27.6%), the pour point was higher than that in Example 1 (an increase of 8-15℃), the working cone penetration was lower than that in Example 1 (a decrease of 21-30 / 0.1mm), the dropping point was lower than that in Example 1 (a decrease of 2-8℃), the stencil oil separation rate and pour point were higher than those in Example 1 (an increase of 0.8-2%), and the low-temperature starting torque at -40℃ was higher than that in Example 1. The torque at -40°C was improved compared to Example 1 (the improvement range was 74.3-116.1 mN·m), the starting torque at -60°C was improved compared to Example 1 (the improvement range was 220.7-376.2 mN·m), and the operating torque at -60°C was improved compared to Example 1 (the improvement range was 109.3-234.6 mN·m). The dynamic viscosity of the greases prepared in Comparative Examples 5-10 at -40°C was greater than 9200 mPa·s.

[0046] Example 2

[0047] Prepare the following raw materials in parts by weight: 29 parts base oil PAO6, 20 parts liquid polybutadiene, 20 parts liquid polyisoprene, 20 parts liquid styrene-isoprene polymer, 7 parts thickener lithium dodecyl stearate soap, 1 part antioxidant (0.5 parts antioxidant L135, 0.5 parts diisooctyl diphenylamine), 1 part rust inhibitor (0.4 parts sodium isopropyl naphthalene sulfonate, 0.6 parts castor oil phosphate salt), 2 parts extreme pressure anti-wear agent 2,5-bis(2'-hydroxydodecyl)-1,3,4-thiadiazole, and 4.5 parts tea polyphenol palmitate. Liquid polybutadiene, liquid polyisoprene, liquid styrene-isoprene polymer, base oil and thickener are mixed evenly in proportion and heated to 165°C. After cooling to 100°C, antioxidant, rust inhibitor, extreme pressure anti-wear agent and tea polyphenol palmitate are added and mixed evenly. The mixture is then homogenized using a homogenizer to obtain the grease.

[0048] The properties of the lubricating grease prepared in Example 2 are as follows: kinematic viscosity at -40℃ is 2015 mmHg. 2 ·s -1 The pour point is -64℃, the working cone penetration is 274 / 0.1mm, the dropping point is 201℃, the oil separation volume of the steel mesh is 0, the starting torque at -40℃ is 116mN·m, the operating torque at -40℃ is 42mN·m, the starting torque at -60℃ is 214mN·m, the operating torque at -60℃ is 71mN·m, and the dynamic viscosity at -40℃ is 5410mPa·s.

[0049] The evaporation loss (200, 22h) of the greases prepared in Examples 1, 2, and Comparative Examples 1-10 was also tested. It was found that the evaporation loss of the grease in Example 2 was the smallest, at 1.27%, while the evaporation loss of the grease in Example 1 was 2.19%. At the same time, the grease in Example 2 had the best oxidation stability, with an oxidation induction period (180℃) of 32 min for the grease in Example 2 and 28 min for the grease in Example 1.

[0050] The above description is merely a preferred embodiment of the present invention. The scope of protection of the present invention is not limited to the above embodiments. All technical solutions falling within the scope of the present invention's concept are within the scope of protection of the present invention. It should be noted that for those skilled in the art, any improvements and modifications made without departing from the principles of the present invention should also be considered within the scope of protection of the present invention.

Claims

1. A grease composition characterized in that, The grease is made of the following raw materials by weight: base oil 20-40 parts, liquid polybutadiene 10-35 parts, liquid polyisoprene 10-30 parts, liquid styrene-isoprene polymer 10-30 parts, thickening agent 4-15 parts, antioxidant 0.1-2 parts, rust inhibitor 0.1-1.5 parts, extreme pressure anti-wear agent 0.5-3.2 parts; The thickening agent is one or more of lithium soap of fatty acid, calcium soap of fatty acid, complex lithium soap, complex aluminum soap, complex barium soap, complex calcium sulfonate, bentonite, silicon dioxide, polyurea, and PTFE micro powder.

2. A grease composition according to claim 1, characterised in that The rust inhibitor is one or more of alkyl naphthalene sulfonate, alkyl sulfonate, naphthenate, fatty acid salt, and castor oil phosphate ester salt.

3. The grease composition of claim 1, wherein The antioxidant is a mixture of amine type antioxidant and phenolic antioxidant.

4. The grease composition of claim 1, wherein The extreme pressure anti-wear agent is one or more of octadecyl phosphite, 2-ethane-dithiocarbamate, molybdenum dithiophosphate, zinc dialkyldithiophosphate, and 2,5-di(2'-hydroxydodecyl)-1,3,4-thiadiazole.

5. The grease composition of claim 1, wherein The base oil is one or more of polyalphaolefin synthetic oil, synthetic ester, alkyl naphthalene, polyisobutylene, polyether, and mineral oil.

6. The grease composition of claim 1, wherein The grease is made of the following raw materials by weight: base oil 29 parts, liquid polybutadiene 20 parts, liquid polyisoprene 20 parts, liquid styrene-isoprene polymer 20 parts, thickening agent 7 parts, antioxidant 1 part, rust inhibitor 1 part, and extreme pressure anti-wear agent 2 parts.

7. A grease composition according to any one of claims 1 to 6, wherein The liquid polybutadiene, liquid polyisoprene, liquid styrene-isoprene polymer, base oil, and thickening agent are mixed in proportion, heated to 150-210℃, and cooled to below 100℃, and then the antioxidant, rust inhibitor, and extreme pressure anti-wear agent are added and mixed uniformly, and the mixture is homogenized by a homogenizer, a grinder, or a high-speed dispersion device to obtain the grease. The grease is made of the following raw materials by weight: base oil 29 parts, liquid polybutadiene 20 parts, liquid polyisoprene 20 parts, liquid styrene-isoprene polymer 20 parts, thickening agent 7 parts, antioxidant 1 part, rust inhibitor 1 part, and extreme pressure anti-wear agent 2 parts. The liquid polybutadiene, liquid polyisoprene, liquid styrene-isoprene polymer, base oil, and thickening agent are mixed in proportion, heated to 150-210℃, and cooled to below 100℃, and then the antioxidant, rust inhibitor, and extreme pressure anti-wear agent are added and mixed uniformly, and the mixture is homogenized by a homogenizer, a grinder, or a high-speed dispersion device to obtain the grease.

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