KR20230056925A - Manufacturing process of extreme pressure calcium composite grease - Google Patents

Abstract

The present invention relates to a process for manufacturing extreme pressure calcium complex grease, comprising: (a) a step of adding base oil and stearic acid to the reaction tank; (b) a step of adding calcium to the reaction tank and stirring sufficiently; (c) a step of adding acetic acid to the reaction tank and stirring; (d) a step of adding 10 to 20 liters of water based on a production volume of 1 Ton into the reaction tank, stirring, and reacting by raising the temperature to 150 to 230℃ until the tank pressure is 3 to 5 kg/cm^2; (e) a step of discharging water vapor after completion of the reaction and rapidly cooling to 90 to 130℃ by adding cooling water; (f) a step of collecting a sample in step (e) to check and adjust the state; and (g) a step of filtering through a filter net. Calcium complex grease according to the present invention is made by reacting stearic acid, lime, and acetic acid at high temperature and pressure, shortening the reaction time compared to conventional grease, reducing the manufacturing defect rate, and producing grease with excellent extreme pressure resistance and water resistance. In addition, the present invention uses excellent synthetic base oil to compensate for the various shortcomings of general mineral oil, and as a result of evaluating its physical properties through mixing experiments, it is possible to manufacture grease that is excellent in terms of performance, including load resistance, wetting resistance, oxidation stability, rust prevention, etc.

Description

Manufacturing process of extreme pressure calcium composite grease

The present invention relates to a process for manufacturing extreme pressure calcium complex grease, and more particularly, to a process for manufacturing extreme pressure calcium complex grease in which stearic acid, lime and acetic acid are added and reacted under high temperature and high pressure conditions.

In recent years, with the development of mechanical technology, the lubricating environment has become more severe and the demand for improved high-temperature performance has increased, and accordingly, greases that satisfy the above requirements are being sought. Among these greases, for example, in lithium soap-based grease, a lithium composite having a wider usable temperature range than lithium grease has been proposed, but the recent demand for lithium raw materials has increased, and supply will be uncertain in the future, or There are concerns that prices will skyrocket. Urea grease is also widely used as a heat-resistant grease, but since the material used as a raw material contains strong toxic substances, great care is required when handling it during the manufacturing process. Therefore, it is necessary to manufacture a grease composition that is stable in supply, has high environmental friendliness, and has excellent heat resistance, water resistance, extreme pressure resistance, and rust and corrosion resistance.

Republic of Korea Patent No. 10-22663290

In order to solve the above problems, an object of the present invention is to provide a process for producing an extreme pressure calcium complex grease.

In order to achieve the above object, the present invention,

In the process of manufacturing extreme pressure calcium complex grease,

(a) introducing base oil and stearic acid into a reaction tank;

(b) adding calcium to the reaction tank and sufficiently stirring;

(c) adding acetic acid to the reaction tank and stirring;

(d) adding 10 to 20 liters of water based on 1 ton of production into the reaction tank, stirring, and reacting by raising the temperature to 150 to 230 ° C. until the tank pressure is 3 to 5 kg / cm 2;

(e) discharging water vapor after completion of the reaction and rapidly cooling the temperature to 90 to 130° C. by adding cooling water;

(f) taking a sample in step (e) to confirm and adjust the intensity; and

(g) filtering through a filter net.

The calcium complex grease according to the present invention reacts stearic acid, lime, and acetic acid at high temperature and high pressure to shorten the reaction time compared to conventional grease and reduce manufacturing defect rates, and is excellent in extreme pressure resistance and water resistance. can be manufactured In addition, in order to compensate for the various disadvantages of general mineral oil, the present invention evaluated the physical properties through mixing experiments using excellent synthetic base oil, and as a result, grease with excellent performance in terms of load capacity, oil separation, oxidation stability, rust prevention, etc. can be manufactured.

Hereinafter, the present invention will be described in more detail.

According to one aspect of the present invention, in the process of manufacturing an extreme pressure calcium complex grease, (a) introducing base oil and stearic acid into a reaction tank; (b) adding calcium to the reaction tank and sufficiently stirring; (c) adding acetic acid to the reaction tank and stirring; (d) adding 10 to 20 liters of water based on 1 ton of production into the reaction tank, stirring, and reacting by raising the temperature to 150 to 230 ° C. until the tank pressure is 3 to 5 kg / cm 2; (e) discharging water vapor after completion of the reaction and rapidly cooling the temperature to 90 to 130° C. by adding cooling water; (f) taking a sample in step (e) to confirm and adjust the intensity; and (g) filtering through a filter net.

Grease is a semi-solid lubricant that is composed of base oil, additives, and thickeners and can be applied to areas where lubrication is difficult. Grease is a semi-solid state when the machine is stopped, and becomes a liquid state when the machine is running. As for grease lubrication, when the thickener forming a network structure receives force, the base oil and additives escape and lubricate the friction part. The thickening agent is in a solid state because the network structure is intertwined in three dimensions, but when shear is applied, the network structure of the thickening agent is oriented in the shear direction and exhibits fluidity. Grease is oriented in the shear direction during lubrication, and when the shear stops, the orientation recombines and returns to its original state. However, when the network structure itself is mechanically subjected to strong shear, the network structure is destroyed, becomes liquid, and loses its properties as grease.

Base oil is the main component (80~90%) of grease and affects lubricity, heat resistance, low temperature resistance, oxidation stability, and rubber resistance. As for lubricating oil, most greases are made of mineral oil, and the applied viscosity may vary depending on the operating conditions. Lubricating oil with low viscosity is applied to high-speed parts, and high-viscosity oil is applied to parts with slow speeds or large loads or high temperatures. In cases where it is difficult to apply with general mineral oil, synthetic lubricant may be applied.

The thickener determines the shape and characteristics of grease, and it forms a semi-solid phase by uniformly dispersing fine fibrous network structures or particles in liquid lubricating oil. In addition, additives impart special properties such as oxidation stability, rust prevention, and extreme pressure resistance to the lease. Types of thickeners include calcium thickeners obtained from lime, sodium thickeners, aluminum thickeners, lithium thickeners, lithium complex thickeners, organic clay thickeners, and polyurea thickeners. Among them, the calcium thickener used in the present invention is suitable for extreme pressure places in contact with water.

Additives are intended to further enhance the performance of grease and meet the performance requirements of users, and various performance-enhancing additives can be used. Additives not only improve the physical and chemical performance of grease, but also extend the life of grease and minimize damage such as abrasion, corrosion, and rust to lubricated metal materials. Types of additives include antioxidants, antiwear additives, extreme pressure additives, rust/corrosion inhibitors, solid additives, and other additives. The additives used in the present invention are a sulfur-based extreme pressure agent, a shear stability additive, an antiwear additive and other additives, and their characteristics are as follows. Sulfur-based extreme pressure agent is a substance produced by reacting sulfur powder with fatty oils including lard, soybean oil, and rapeseed oil, and acts to prevent wear of friction surfaces. Shear stability additives change the consistency of grease when mechanical shear action is applied to grease, and the property of resisting this change is called shear stability. If shear stability additives are not added, when mechanical action is applied to the grease, the fibrous structure (network fiber) of the grease gradually disintegrates, and when mechanical action (shear) is applied for a long time, the network structure is eventually destroyed and the grease loses its shape. do. Shear stability additives reduce the frictional force in the shear area so that the fiber structure of grease does not break, and representative materials include trimellitate, polytetrafluoroethylene, and antiwear additives. Wear resistance improving additives are additives that improve wear resistance by forming a thin coating layer on the frictional boundary surface and slipping caused by weak bonding force (van der Waals bond) between layers due to the crystal structure. Fluorocarbon resin, polytetra Fluorethylene, bolybudenine disulfide, tungsten disulfide, and graphite are used.

Conventional methods for producing calcium complex grease are generally at normal pressure, but in the present invention, the grease is reacted at high temperature and high pressure to produce grease with excellent extreme pressure resistance, water resistance, rust/corrosion resistance, and mechanical shear stability. Temperature and pressure settings are very important.

First, in step (a), base oil is added to the reaction tank, and stearic acid is added at 60 to 80° C. and then dissolved.

Next, in step (b), lime is dissolved in base oil in advance and introduced into the reaction tank at 70 to 90 °C. Thereafter, the mixture is sufficiently stirred for 30 minutes to 1 hour 30 minutes.

Next, in step (c), acetic acid is slowly added to the reaction tank at 70 to 90° C. and reacted while stirring for 20 to 40 minutes.

Next, in step (d), water is put into the reaction tank, and the reaction tank is sealed and heated. At this time, 10 to 20 liters of water is added based on 1 Ton of water production, and the tank pressure is 3 to 5 kg / cm 2 or the temperature is heated to 150 to 230 ° C. Since the pressure can sufficiently reach the required pressure with the vapor pressure generated as a by-product during the reaction, a device for applying a separate pressure is not required. The reaction is continued for 30 minutes to 1 hour 30 minutes. In addition, as a way to improve the reaction of grease, add 4 to 6 liters of water at a pressure of 0 and a temperature of 90 to 130 ° C, close the valve, and raise the temperature to increase the pressure again. At this time, the maximum pressure Wait until it reaches 3 to 4 kg/cm 2 , terminate the reaction, perform a second vent, and then cool.

Next, in step (e), rapid cooling and natural cooling are performed by discharging water vapor and introducing cooling water. When discharging steam, care must be taken not to leak grease together, and if normal pressure is maintained after discharging steam, coolant should be injected. After the cooling water is introduced, the reactant is rapidly cooled to 90 to 130 ° C., which is to uniformize the grease fiber structure and strengthen the binding force. If there is no cooling facility, the temperature can be gradually cooled to 90 to 130 ° C by natural cooling.

Next, in step (f), a sample is taken to confirm and adjust the intensity. A point to note is that when checking and adjusting the consistency in the first intermediate test, if the consistency is stiff, additional base oil can be added, but if it is thin, there is no way to properly adjust the consistency, so the remaining base oil must be added carefully. If there is no abnormality as a result of the 1st interim inspection, add the necessary additives in order and reconfirm the consistency with the 2nd interim inspection. The additives used in the present invention are sulfur-based extreme pressure additives, shear stability additives, wear resistance improving additives and other additives. Other additives may include adhesion improvers, antioxidants, anti-rust and wear-resistance improvers, corrosion additives, and the like.

Next, step (g) is a step of filtering the product using a filter net. At this time, the filtration uses a filter net of 150 to 250 mesh size, preferably a filter net of 180 to 220 mesh size.

Hereinafter, examples will be described in detail in order to specifically describe the present specification. However, embodiments according to the present specification may be modified in many different forms, and the scope of the present specification is not construed as being limited to the embodiments described below. The embodiments herein are provided to more completely explain the present specification to those skilled in the art.

<Example>

Example 1 - Preparation of high extreme pressure complex calcium grease

After adding about 4/5 of the base oil to the reaction tank, stearic acid was added in a fixed amount at about 70 ° C and completely dissolved, and then calcium lime was added in a fixed amount at about 80 ° C and stirred sufficiently for about 1 hour. Then, acetic acid was slowly added at the same temperature, and the reaction was continued while stirring continuously for about 30 minutes. Then, based on 1 Ton of production, add 15 liters of water, seal and heat the reaction tank while continuously stirring, and continue heating until the tank pressure reaches 3.5 kg/cm2 or the temperature reaches 190 ° C, and the reaction is carried out at the same temperature for 1 hour. persisted. When the reaction was completed, water vapor was slowly discharged, and when the pressure was maintained normal after the water vapor was discharged, cooling water was added to rapidly cool the reactant to 110 ° C. After opening the reaction tank, taking a sample of the reactant and observing the state, the consistency was adjusted using base oil as the first intermediate inspection. Initiation was controlled by inspection. As a result of the second intermediate inspection, if there was no problem in the consistency, it was filtered through a 200 mesh filter net and then filled into the packaging container.

The reaction mechanism of the calcium complex grease prepared in consideration of the above process is as follows, and RCOOCH ₃ Ca is produced by the reactions of Formulas 1 and 2 below.

Composition of manufactured calcium complex grease (%) sample number base oil hwanggye
extreme pressure
additive shear
stability
additive Wear resistance improvement
additive calcium stearic acid acetic acid Other additives subtotal One 76.6 2.0 0.5 0.5 2.8 9.0 2.6 6.0 100 2 77.5 2.5 1.0 1.0 3.0 9.0 2.8 3.2 100 3 71.3 3.0 0.5 1.5 3.2 9.5 3.0 8.0 100 4 71.7 3.5 1.0 2.0 3.4 9.5 3.2 5.7 100 5 72.1 4.0 0.5 0.5 2.8 10.0 2.6 7.5 100 6 73.5 4.5 1.0 1.0 3.0 10.0 2.8 4.2 100 7 67.3 5.0 0.5 1.5 3.2 10.5 3.0 9.0 100 8 68.7 5.5 1.0 2.0 3.4 10.5 3.2 5.7 100

Example 2 - Evaluation of general properties for composition ratio for each sample

Load capacity evaluation (Timgen method)

According to KS M 2026, when the sample is immersed in the lower half of the test tube, the tester is driven at the specified speed and the automatic load is driven to apply the load to the lubricating oil film between the test cups. The maximum load obtained without causing damage such as abrasion marks The value should be more than 12.2kgf.

Evaluation of weaning degree (100℃/24hr, %)

In accordance with KS M 2050, fill the sample in a beaker with an iron net and heat it to obtain the weight of the separated oil, and the oil separation rate (%) should be 2% or less.

Copper plate corrosion evaluation

In accordance with KS M 2088, the polished copper plate was put into grease and maintained at 100 ° C for 24 hours, and then the presence or absence of discoloration of the copper plate was examined.

<Results and evaluation>

Evaluation of general properties for composition ratio by sample

sample number Load capacity test (Timken method) reason copper corrosion One 9.5 1.24 discoloration 2 6.8 1.18 no change 3 12.2 1.35 no change 4 9.5 1.47 no change 5 13.6 1.50 no change 6 9.5 1.45 no change 7 15.9 1.20 no change 8 13.6 1.34 discoloration

Table 2 shows the results of the load bearing (Timken method) test, oil separation and copper corrosion test for the composition ratio of each sample. Referring to Tables 1 and 2, it was confirmed that sample 7 in Table 1, which had the smallest content of base oil and the largest amount of extreme pressure additive, was excellent in load capacity. In addition, the higher the content of calcium, stearic acid and acetic acid, the higher the weaning degree. It was confirmed that corrosion and bubbles occurred when the composition ratio of the anti-rust additive and antioxidant was less than the composition ratio, and when the composition ratio was higher than the composition ratio, rust prevention performance was not improved and manufacturing cost only increased. In addition, other additives, including antioxidants and corrosion inhibitors, also have no anti-oxidation and anti-corrosion effects when the composition ratio is less than that.

Considering load capacity, oil separation and corrosion, the mixing ratio of sample 7 is 67.3% of base oil, 5.0% sulfur-based extreme pressure additive, 0.5% shear stabilization additive, 1.5% anti-wear additive, 3.2% calcium, 10.5% stearic acid, and 3.0% acetic acid. , 9.0% of other additives (adhesion improver, antioxidant, anti-rust and wear-resistance improver, corrosion additive) is most preferred.

Claims (3)

In the process of manufacturing extreme pressure calcium complex grease,
(a) introducing base oil and stearic acid into a reaction tank;
(b) adding calcium to the reaction tank and sufficiently stirring;
(c) adding acetic acid to the reaction tank and stirring;
(d) adding 10 to 20 liters of water based on 1 ton of production into the reaction tank, stirring, and reacting by raising the temperature to 150 to 230 ° C. until the tank pressure is 3 to 5 kg / cm 2;
(e) discharging water vapor after completion of the reaction and rapidly cooling the temperature to 90 to 130° C. by adding cooling water;
(f) taking a sample in step (e) to confirm and adjust the intensity; and
(g) filtering through a filtering net;
According to claim 1,
In the step (f), the first intermediate inspection is to adjust the consistency with the base oil, and the second intermediate inspection is to adjust the consistency by adding sulfur-based extreme pressure additives, shear stabilization additives, antiwear additives and other additives. Manufacturing process of calcium complex grease.
According to claim 1,
The step (g) is a process for producing an extreme pressure calcium complex grease, characterized in that using a filter net of 150 to 250 mesh size.