Sealing grease composition and preparation method thereof

Abstract

The present application relates to the field of sealing and lubricating technology, and specifically discloses a sealing grease composition and a preparation method thereof. The sealing grease composition comprises the following components in parts by weight: 15-35 parts of base oil, 15-50 parts of thickener, 2-6 parts of rust inhibitor, 0.5-1.5 parts of water repellent, and 0.5-2 parts of antioxidant; the base oil is a mixture of polypropylene adipate and oxidized castor oil in a weight ratio of 1:(0.5-2); the thickener is C 16 ‑C 18 A complex barium soap formed by the reaction of fatty acid, nitrilotriacetic acid and barium hydroxide, wherein the C 16 ‑C 18 The weight ratio of fatty acid to nitrilotriacetic acid is 1:(1-2). The sealing grease composition prepared in the present application has excellent resistance to media such as ammonia water and sealing performance, and has high adhesion, and is suitable for lubrication and sealing of pipelines and valves in chemical production.

Description

Technical Field

[0001] The present application relates to the technical field of sealing and lubrication, and more specifically, to a sealing grease composition and a preparation method thereof. Background Art

[0002] Grease is a thick, oily semi-solid substance used in the friction parts of machinery to lubricate and seal. It is also used on metal surfaces to fill gaps and prevent rust. Grease is mainly made of mineral oil and thickeners. Most greases are used for lubrication and are called anti-friction greases. Anti-friction greases mainly reduce mechanical friction and prevent mechanical wear. They also prevent metal corrosion and seal against dust. The working principle of grease is that the thickener keeps the oil in the position where lubrication is required. When there is a load, the thickener releases the oil, thereby playing a lubricating role.

[0003] Some mechanical equipment, locomotives, pipelines, and valves need to work in media such as gasoline, kerosene, lubricating oil, water, ethanol, and chemicals. The static seals of the valves in these equipment structures and the sealing and lubrication of the sealing surfaces are particularly important.

[0004] In the chemical industry, pipelines and valves in fertilizer production processes require sealing grease; however, this grease may come into contact with ammonia water. As existing greases generally have poor compatibility with ammonia water, the sealing performance of equipment in contact with ammonia water (such as pipelines and valves) is poor after applying grease, which poses a risk of pipeline and valve leakage. Summary of the invention

[0005] In order to solve the above technical problems, the present application provides a sealing grease composition and a preparation method thereof. The sealing grease composition has excellent resistance to media such as ammonia water and sealing performance, and has high adhesion, and is suitable for lubrication and sealing of pipelines and valves in chemical production.

[0006] In a first aspect, the present application provides a sealing grease composition, which adopts the following technical solution:

[0007] A sealing lubricating grease composition comprises the following components in parts by weight: 15-35 parts of base oil, 15-50 parts of thickener, 2-6 parts of rust inhibitor, 0.5-1.5 parts of water repellent, and 0.5-2 parts of antioxidant.

[0008] The base oil may be a combination of one or more of mineral, synthetic, plant, and animal sources. The mineral-based base oil may be a mineral oil, such as a mineral oil produced by solvent refining or hydrogen processing. The synthetic-based base oil includes C 10 -C 50One or more of hydrocarbon polymers, ester polymers, and ether polymers, specifically polyolefins, such as α-olefin oligomers and polybutene; or polyalkylene glycols, such as polyethylene glycol and propylene glycol; or diesters, such as di-2-ethylhexyl sebacic acid and di-2-ethylhexyl adipate; or polyol esters, such as trimethylolpropane ester and pentaerythritol ester; or perfluoroalkyl ethers; or silicone oils; or polyphenylene ethers, etc.

[0009] Preferably, the base oil is a mixture of polypropylene adipate and oxidized castor oil in a weight ratio of 1:(0.5-2).

[0010] Preferably, the viscosity of the polypropylene adipate at 100°C is 200-250 mm 2 / s.

[0011] Preferably, the viscosity of the oxidized castor oil at 100°C is 50-60 mm 2 / s.

[0012] Castor oil itself has a high hydroxyl value and high functionality. After oxidation treatment, it can have excellent oil resistance. However, oxidized castor oil has poor thermal stability and poor low-temperature performance. By mixing it with polypropylene adipate as a base oil, the temperature resistance of the grease can be improved, and the viscosity changes little under temperature changes.

[0013] Preferably, the thickener is C 16 -C 18 A complex barium soap formed by the reaction of fatty acid, nitrilotriacetic acid and barium hydroxide, wherein the C 16 -C 18 The weight ratio of fatty acid to nitrilotriacetic acid is 1:(1-2).

[0014] Preferably, the C 16 -C 18 The fatty acid used is dodecyl hydroxystearic acid.

[0015] The thickener prepared by the present application has the characteristics of high melting point, strong water resistance and good working stability, low cost, and is not easy to agglomerate during use, so it is suitable for large-scale promotion and use.

[0016] Preferably, the rust inhibitor is one or a mixture of two of barium petroleum sulfonate and benzotriazole.

[0017] The rust inhibitor molecules can form a strong adsorption film on the metal surface to inhibit the contact of oxygen and water with the metal, thus preventing the metal from rusting.

[0018] Preferably, the water repellent is a mixture of sodium fatty alcohol polyoxyethylene ether carboxylate and ammonium zirconium carbonate in a weight ratio of 1:(0.1-1).

[0019] Sodium polyoxyethylene fatty alcohol ether carboxylate can capture polar substances such as water and acid dispersed in grease and contain them in micelles or flocs, thereby playing a water-resistant role. In addition, sodium polyoxyethylene fatty alcohol ether carboxylate can also replace water on the metal surface, thereby draining the water on the metal surface and playing a dehydrating role. The addition of ammonium zirconium carbonate can further improve the water resistance of grease, making the grease not dissolve or become thin when it comes into contact with water, and the lubrication and sealing performance is not reduced.

[0020] Preferably, the antioxidant is one of diisooctyl diphenylamine, bisphenol A and diphenylamine.

[0021] The addition of the above antioxidants can make the grease less prone to oxidation during use and increase its service life.

[0022] Preferably, the sealing grease composition further contains 10-20 parts by weight of a filler, wherein the filler is one of mica powder, calcium carbonate and calcium phosphate.

[0023] The above-mentioned mineral powder has good adhesion and can be added into grease to improve its sealing and adhesion.

[0024] In a second aspect, the present application provides a method for preparing a sealing grease composition, using the following technical solution:

[0025] A method for preparing a sealing grease composition comprises the following steps:

[0026] S1, polypropylene adipate and oxidized castor oil are mixed, sheared and stirred to obtain a mixed base oil;

[0027] S2, C 16 -C 18 Fatty acid, nitrilotriacetic acid and the mixed base oil obtained in step S1 are mixed, heated to 85-95° C., barium hydroxide is added, reacted for 2-4 hours, and then the temperature is further raised to 160-170° C. after dehydration, and heating is stopped;

[0028] S3, adding a rust inhibitor, an antioxidant, and a water repellent, and cyclically shearing to obtain the sealing grease composition.

[0029] Preferably, in step S3, a filler is further added, and the filler is one of mica powder, calcium carbonate and calcium phosphate.

[0030] The base oil of the present application adopts a mixture of polypropylene adipate and oxidized castor oil, so that the grease has excellent oil resistance and high temperature resistance, and the viscosity changes little under temperature changes.

[0031] The thickener prepared by the present application has the characteristics of high melting point, strong water resistance and good working stability, low cost, and is not easy to agglomerate during use, and is suitable for large-scale promotion and use. After testing, the cone penetration of the sealing grease composition prepared by the present application is 220 (in units of 0.1 mm), and the dropping point is greater than 250°C.

[0032] The water repellent used in the present application is a mixture of sodium fatty alcohol polyoxyethylene ether carboxylate and ammonium zirconium carbonate, which can greatly enhance the grease composition's resistance to chemicals such as ammonia water, does not dissolve or oxidize upon contact with water, has strong water resistance, and has a broad application prospect. DETAILED DESCRIPTION

[0033] The present application is further described in detail below with reference to the embodiments.

[0034] The present application provides a sealing grease composition, comprising the following components in parts by weight: 15-35 parts of base oil, 15-50 parts of thickener, 2-6 parts of rust inhibitor, 0.5-1.5 parts of water repellent, and 0.5-2 parts of antioxidant;

[0035] The base oil is a mixture of polypropylene adipate and oxidized castor oil in a weight ratio of 1:(0.5-2);

[0036] The thickener is C 16 -C 18 A complex barium soap formed by the reaction of fatty acid, nitrilotriacetic acid and barium hydroxide, wherein the C 16 -C 18 The weight ratio of fatty acid to nitrilotriacetic acid is 1:(1-2).

[0037] The viscosity of polypropylene adipate at 100°C is 200-250 mm 2 / s; the viscosity of oxidized castor oil at 100°C is 50-60mm 2 / s.

[0038] Among them C 16 -C 18 The fatty acid used is dodecyl hydroxystearic acid.

[0039] The rust inhibitor is one of petroleum barium sulfonate and benzotriazole or a mixture of the two.

[0040] The water repellent is a mixture of sodium fatty alcohol polyoxyethylene ether carboxylate and ammonium zirconium carbonate in a weight ratio of 1:(0.1-1).

[0041] The antioxidant is one of diisooctyl diphenylamine, bisphenol A and diphenylamine.

[0042] Furthermore, the sealing grease composition also contains 10-20 parts by weight of a filler, wherein the filler is one of mica powder, calcium carbonate and calcium phosphate.

[0043] The present application also provides a method for preparing a sealing grease composition, comprising the following steps:

[0044] S1, mixing polypropylene adipate and oxidized castor oil, shearing and stirring to obtain a mixed base oil;

[0045] S2, C 16 -C 18 Fatty acid, nitrilotriacetic acid and the mixed base oil obtained in step S1 are mixed, heated to 85-95° C., barium hydroxide is added, reacted for 2-4 hours, and then the temperature is further raised to 160-170° C. after dehydration, and heating is stopped;

[0046] S3, adding a rust inhibitor, an antioxidant, and a water repellent, and cyclically shearing to obtain the sealing grease composition.

[0047] In step S3, a filler is added, and the filler is one of mica powder, calcium carbonate and calcium phosphate.

[0048] Some of the raw materials used in the examples and comparative examples of this application are shown in the following table:

[0049]

[0050]

[0051] Example

[0052] Example 1

[0053] A sealing grease composition is prepared by the following steps:

[0054] S1, mixing 1 kg of polypropylene adipate and 0.5 kg of oxidized castor oil, shearing and stirring to obtain a mixed base oil;

[0055] S2, 0.2 kg of dodecyl hydroxystearic acid, 0.4 kg of nitrilotriacetic acid and the mixed base oil obtained in step S1 are mixed, the temperature is raised to 85° C., 0.55 kg of barium hydroxide is added, and after reacting for 2 hours, dehydration is continued and the temperature is raised to 165° C., and heating is stopped;

[0056] S3, adding 0.2 kg of rust inhibitor, 0.05 kg of antioxidant, and 0.055 kg of water repellent, and cyclically shearing to obtain the sealing grease composition.

[0057] In this embodiment, the rust inhibitor is benzotriazole, the antioxidant is diphenylamine, and the water repellent is a mixture of sodium fatty alcohol polyoxyethylene ether carboxylate and ammonium zirconium carbonate in a mass ratio of 1:0.1.

[0058] Example 2

[0059] A sealing grease composition is prepared by the following steps:

[0060] S1, mixing 1.8 kg of polypropylene adipate and 0.9 kg of oxidized castor oil, shearing and stirring to obtain a mixed base oil;

[0061] S2, 0.3 kg of dodecyl hydroxystearic acid, 0.6 kg of nitrilotriacetic acid and the mixed base oil obtained in step S1 are mixed, the temperature is raised to 90° C., 1.0 kg of barium hydroxide is added, and after reacting for 3 hours, the dehydration is continued and the temperature is raised to 170° C., and the heating is stopped;

[0062] S3, adding 0.4 kg of rust inhibitor, 0.13 kg of antioxidant, and 0.11 kg of water repellent, and cyclically shearing to obtain the sealing grease composition.

[0063] In this embodiment, the rust inhibitor is benzotriazole, the antioxidant is diphenylamine, and the water repellent is a mixture of sodium fatty alcohol polyoxyethylene ether carboxylate and ammonium zirconium carbonate in a mass ratio of 1:0.1.

[0064] Example 3

[0065] A sealing grease composition is prepared by the following steps:

[0066] S1, mixing 2.4 kg of polypropylene adipate and 1.2 kg of oxidized castor oil, shearing and stirring to obtain a mixed base oil;

[0067] S2, 0.4 kg of dodecyl hydroxystearic acid, 0.8 kg of nitrilotriacetic acid and the mixed base oil obtained in step S1 are mixed, the temperature is raised to 95° C., 1.2 kg of barium hydroxide is added, and after reacting for 4 hours, the temperature is further raised to 170° C. after dehydration, and the heating is stopped;

[0068] S3, adding 0.6 kg of rust inhibitor, 0.2 kg of antioxidant, and 0.15 kg of water repellent, and cyclically shearing to obtain the sealing grease composition.

[0069] In this embodiment, the rust inhibitor is benzotriazole, the antioxidant is diphenylamine, and the water repellent is a mixture of sodium fatty alcohol polyoxyethylene ether carboxylate and ammonium zirconium carbonate in a mass ratio of 1:0.1.

[0070] Example 4

[0071] A sealing grease composition, the raw material dosage is the same as that of Example 1, and the difference from Example 1 is that in step S3, 1.0 kg of mica powder is also added.

[0072] Embodiment 5-8

[0073] A sealing grease composition, the preparation method is the same as that of Example 4, and the difference from Example 4 is that the amounts of some raw materials are different, see Table 1 for details.

[0074] Table 1 Sealing grease composition formula of Examples 1-8 (unit: kg)

[0075]

[0076] Comparative Example

[0077] Comparative Example 1

[0078] A sealing grease composition, the preparation method is the same as that of Example 1, and the difference from Example 1 is that the amount of some raw materials is different, see Table 2 for details

[0079] Table 2 Sealing grease composition formula of Example 1 and Comparative Examples 1-3 (unit: kg)

[0080]

[0081]

[0082] Performance testing

[0083] The sealing grease compositions prepared in Examples 1-8 and Comparative Examples 1-3 were tested for their performance, and the test results are recorded in Table 3.

[0084] Adhesion test: The test is conducted in accordance with the "Determination of Water Spray Resistance of Grease" SH / T0643-1997. According to the test standard, the grease composition is applied to a stainless steel plate, and water spray is performed at the specified test temperature and pressure. After 5 minutes, the spray weight loss percentage of the grease composition is measured to evaluate its adhesion to the metal surface.

[0085] Water resistance test: 75 g of the sealing grease composition and 25 g of water were placed in a beaker, stirred with a glass rod at a frequency of 60 times / min for 5 min, and then left for 8 h to observe whether water was separated out.

[0086] Anti-corrosion performance test: The aqueous sealing grease composition that has passed the water resistance test is further subjected to an anti-corrosion test in accordance with the "Test Method for Anti-Corrosion Performance of Grease" GB / T5018-2008.

[0087] Ammonia resistance test: Take 20g of the sealing grease composition, add it to a 100mL test tube, pass ammonia gas into the bottom of the test tube, and observe the state of the grease composition after standing for 24 hours.

[0088] High temperature resistance test: Take 5g of the sealing grease composition, add it to a glass dish, scrape the grease surface flat, put it into a 200℃ oven, and observe the state of the grease composition after standing for 5 hours.

[0089] Table 3 Performance test results

[0090]

[0091]

[0092] It can be seen from the test results in Table 3 that the sealing grease composition prepared in the present application has excellent resistance to media such as water and ammonia water, and excellent temperature resistance, is suitable for sealing lubrication of pipelines and valves, and has great application prospects.

[0093] Comparing the test results of Examples 1 and 4, it can be seen that the addition of mica powder can significantly improve the adhesion performance of the grease composition.

[0094] Comparing the test results of Example 1 and Comparative Examples 1-2, it can be seen that the present application uses a mixture of polypropylene adipate and oxidized castor oil as the base oil, which can significantly improve the high temperature resistance of the grease composition and also improve its adhesion performance to a certain extent.

[0095] Comparing the test results of Example 1 and Comparative Example 3, it can be seen that the thickener prepared in the present application can greatly improve the grease composition's resistance to water, ammonia water and other media, and has a positive effect on its adhesion performance.

[0096] The above is only the preferred implementation of the present application. The protection scope of the present application is not limited to the above embodiments. All technical solutions under the concept of the present application belong to the protection scope of the present application. It should be pointed out that for ordinary technicians in this technical field, some improvements and modifications without departing from the principle of the present application should also be regarded as the protection scope of the present application.

Claims

1. A sealing grease composition, characterized in that: The invention comprises the following components in parts by weight: 15-35 parts of base oil, 15-50 parts of thickener, 2-6 parts of rust inhibitor, 0.5-1.5 parts of water repellent, 0.5-2 parts of antioxidant and 10-20 parts of filler; The base oil is a mixture of polypropylene adipate and oxidized castor oil in a weight ratio of 1:(0.5-2); The thickener is C 16 -C 18 A complex barium soap formed by the reaction of fatty acid, nitrilotriacetic acid and barium hydroxide, wherein the C 16 -C 18 The weight ratio of fatty acid to nitrilotriacetic acid is 1:(1-2); The water repellent is a mixture of sodium fatty alcohol polyoxyethylene ether carboxylate and ammonium zirconium carbonate in a weight ratio of 1:(0.1-1); The filler is one of mica powder, calcium carbonate and calcium phosphate.

2. The sealing grease composition according to claim 1, characterized in that: The viscosity of the polypropylene adipate at 100°C is 200-250 mm 2 / s.

3. The sealing grease composition according to claim 1, characterized in that: The viscosity of the oxidized castor oil at 100°C is 50-60 mm 2 / s.

4. The sealing grease composition according to claim 1, characterized in that: The C 16 -C 18 The fatty acid used is dodecyl hydroxystearic acid.

5. The sealing grease composition according to claim 1, characterized in that: The rust inhibitor is one of petroleum barium sulfonate and benzotriazole or a mixture of the two.

6. The sealing grease composition according to claim 1, characterized in that: The antioxidant is one of diisooctyl diphenylamine, bisphenol A and diphenylamine.

7. The method for preparing the sealing grease composition according to any one of claims 1 to 6, characterized in that: The following steps are involved: S1, mixing polypropylene adipate and oxidized castor oil, shearing and stirring to obtain a mixed base oil; S2, C 16 -C 18 Fatty acid, nitrilotriacetic acid and the mixed base oil obtained in step S1 are mixed, heated to 85-95° C., barium hydroxide is added, reacted for 2-4 hours, and then the temperature is further raised to 160-170° C. after dehydration, and heating is stopped; S3, adding rust inhibitor, antioxidant, water repellent and filler, and cyclically shearing to obtain the sealing grease composition.

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