JPH01284591A - Urea grease composition - Google Patents

Abstract

PURPOSE:To realize a higher content of a lubricating oil in a grease, a longer life of a grease, an improvement in stability, etc., by incorporating a diurea compound as a thickening agent into a base oil comprising a mineral oil or a synthetic oil. CONSTITUTION:A base oil comprising a mineral oil or a synthetic oil and having a viscosity of, e.g., 32cSt (at 100 deg.C) is mixed with 2-25wt.% diurea compound of the formula [wherein R1 is a 6-15C divalent aromatic hydrocarbon group; R2 and R3 are each 3C or 4C and 16-18C straight-chain or branched, or (un)saturated alkyl, provided that the 3C or 4C alkyl accounts for 20-90mol% in R2 and R3] (e.g., diphenylmethane 4,4'-diisocyanate).

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention provides a urea grease composition that makes it possible to significantly improve the lubricating life by using a silarea compound with high thickening ability as a thickener. It is about things.

(Prior Art) Conventionally, grease is defined as a semi-solid or solid lubricant made by dispersing a thickener in a liquid lubricant, and includes lubricants to which other ingredients are added to improve specific performance. Microscopically, thickeners (ranging from spherical particles to fibers with length and width) are dispersed in the lubricating oil as micelles, and the thickener retains the oil. is taking. For this reason, grease used for rotating and sliding parts such as ball hair rings and roller bearings is difficult to soften even when the grease itself is mixed, so it is necessary to have good mixing stability so that it does not scatter or leak. , and it is desirable that the torque be small. In further cases, a sealing effect may be required, such as the formation of a grease accumulation area by causing a so-called channeling phenomenon near the race surface of the bearing. Since the base oil of grease is held by a thickener, the oil that oozes out from the thickener due to shearing etc. does not have the hardness of a grease and does not have the original performance of a grease. When strong shear is applied, the micellar structure formed by the thickener is destroyed, and even after the shear is removed, the grease does not return to its original properties.

Conventionally, many thickeners have been developed to thicken lubricating oils to produce grease. This is because there are many different environments, operating conditions, bearing shapes, and lubrication methods where grease is applied, and a wide variety of thickeners have been developed to change the characteristics of grease to suit these conditions. It is important to select the appropriate lubricating grease for the conditions of use, but there are many combinations of thickeners, lubricants, and additives, and it is extremely difficult to select a grease that is suitable for the usage environment. It's difficult.

The lubricating behavior of grease is determined by its thixotropic property (
It is said that due to thixotropy, the entire product becomes soft and lubricated, and when the movement of the grease stops, it returns to its original hardness, but in reality, such an ideal phenomenon is unlikely to occur. Therefore, it is better to use a gelling agent with strong thixotropic properties.
Unlike grease that has been hardened with a thickener, a grease that has been hardened with a gelling agent is easily softened by heat or shearing and cannot be used continuously.

Therefore, the applicant of the present invention disclosed in Japanese Unexamined Patent Publication No. 58-219297 that the lubricating oil is thickened by using both a grease thickener and a gelling agent that has the ability to solidify an organic liquid in a very small amount. A grease composition was proposed.

Here, the thickener is a liquid (in the case of the present invention, lubricating oil)
The action of increasing oil content is due to the micellar structure, in which fibers form a network structure that retains oil. It requires relatively more thickener to maintain its structure and is relatively resistant to shear.

On the other hand, gelling agents are almost the same as thickeners in terms of their ability to solidify liquids, but compared to thickeners, they have the ability to thicken liquids with a smaller amount and have a higher static level. It exhibits hardness, but is easily softened by heat and/or shearing. Also, unlike thickeners, gelling agents can solidify liquids by solubilizing or stably dispersing them in liquids. Therefore, it is difficult or insufficient to create and use greases with gelling agents alone.

(Problems to be Solved by the Invention) The grease composition described in JP-A-58-219297 can be used for multiple purposes and in principle have a long life by using two components, a thickener and a gelling agent. However, the selection of combinations of two components was limited.

(Means for Solving the Problems) In order to solve the above problems, the present inventors investigated various metal soaps, composite metal soaps, organically treated bennatoites, urea compounds, and gelling agents, and found that the terminal hydrocarbon Through a specific combination of groups, we have discovered a Silarea compound that has an extremely high thickening effect, and confirmed that the same effect can be obtained with a grease composition using this Silarea compound.
The present invention has been achieved.

That is, the present invention is based on the following general formula (wherein R1 is a divalent aromatic hydrocarbon group having 6 to 15 carbon atoms, R2 and R3 are 3, 4, and 1 carbon atoms).
It represents a 6 to 18 linear or branched, saturated or unsaturated alkyl group, and the proportion of the alkyl group having 3 or 4 carbon atoms in R2 and R,3 is 20 to 90 mol%. The present invention relates to a urea grease composition characterized in that it contains 2 to 25% by weight of the Silarea compound represented by () as a thickener based on the base oil, which is mineral oil or synthetic oil.

(Functions and Effects) The present invention is characterized in that it uses a thickener that has an extremely high thickening ability compared to conventional greases, and therefore the amount of thickener is 40 to 80% by weight of the amount conventionally used. Grease with a harder consistency grade is obtained. As a result, 6-1) By reducing the added weight, the ratio of lubricating oil increases, and the stirring resistance of the grease that occurs when the bearing rotates becomes smaller. Therefore, the resulting temperature rise and low torque performance are further improved, thermal deterioration of the grease is suppressed, and the life of the grease and, ultimately, the life of the hair ring are extended.

2) Grease with a hard consistency accumulates near the rotating part of the hair ring and forms a seal, preventing foreign matter from entering the lubricated part and preventing grease from flowing out.

3) Since the grease uses a urea compound as a thickener, it is expected to have good heat resistance, water resistance, and oxidation stability.

Furthermore, it is expected that it will show good pumping performance despite the hard consistency due to less thickening, and that the acoustic characteristics will be improved due to the high proportion of lubricating oil.

Although the reason why such an effect can be obtained by the configuration of the present invention has not been completely elucidated, the following is generally considered to be the reason. Grease thickeners need to have appropriate oleophobicity and lipophilicity toward the base oil. In particular, in the case of a urea grease thickener, if the terminal group in the molecule, ie, R2 and/or R3 in formula (1), is an alkyl group having 3 or 4 carbon atoms, it has excellent lipophobicity with respect to the base oil. Furthermore, in the formula (1), when R2 and/or R3 is an alkyl group having 16 to 1B carbon atoms, the lipophilic property is a) Vero.

From the above, in R2 and R3, the number of carbon atoms is 3.
Alternatively, a combination of an alkyl group having 4 carbon atoms and an alkyl group having 16 to 18 carbon atoms can provide both appropriate lipophobicity and lipophilicity for the base oil. Then, they discovered a urea compound with extremely high thickening ability, leading to the present invention.

As a result of extensive studies by the present inventors regarding the composition that is effective in the present invention, the following has become clear.

(1) Molar ratio of alkyl groups having 3 or 4 carbon atoms, that is, [
[alkyl group with 3 or 4 carbon atoms]/([alkyl group with 3 or 4 carbon atoms] + [alkyl group with 16 to 18 carbon atoms]) shows the smallest value around 50%, and the consistency is increased. The effect is maximum. Moreover, if it is smaller than 20% or larger than 90%, the consistency will increase dramatically and the thickening effect will be poor.

Therefore, the molar ratio of alkyl groups having 3 or 4 carbon atoms is 20
Or it needs to be 90%.

(2) Molar ratio of alkyl groups having 3 or 4 carbon atoms is 20%
If it is less than that, the dropping point will decrease. Therefore, it is necessary that the molar ratio of the alkyl group having 3 or 4 carbon atoms is 20% or more.

(3) If the content of the diurea compound of the present invention is less than 2% by weight, it will not be effective as a grease and will become close to liquid, making it impossible to achieve the purpose of the present invention, and if it exceeds 25% by weight, the grease will increase. As a thickener, it cannot be expected to have an economical addition effect, and if it is added even more, the grease will become too hard and will not be able to exhibit sufficient lubricating effect.

Furthermore, the urea grease composition of the present invention may contain additives such as extreme pressure agents, antioxidants, oiliness agents, rust preventives, corrosion inhibitors, viscosity index improvers, etc. to further improve performance without impairing its properties. can be added.

(Example) The content of the present invention will be explained in more detail with reference to Examples below.

Fruit ↓ Diphenylmethane-4,4'-diisocyanate 540
g to 107 g of mineral oil (viscosity 32.0 cS at 100°C)
t) and heated to 80'C to uniformly disperse the mixture.

A mixture of 8.4 g of octadecylamine, 0.7 g of n-butylamine, and 107 g of the above-mentioned mineral oil was heated to 80 DEG C. to dissolve the mixture, and when the mixture was stirred vigorously, a gel-like substance was immediately formed. Continue stirring for about 30 minutes and heat to 200'C.
After heating the mixture to room temperature, it was kneaded in a three-roll mill to obtain the desired grease.

Diphenylmethane-4,4'-diisocyanin)
0g to 102g mineral oil (viscosity 32.0cS at 100°C)
t) and heated to 80°C to uniformly disperse the mixture.

A mixture of 7.0 g of octadecylamine, 1.0 g of n-butylamine, and 102 g of the above-mentioned mineral oil was heated to 80°C to dissolve the mixture, and when the mixture was stirred vigorously, a gel-like substance was immediately formed. Continue stirring for about 30 minutes and heat to 200°C.
After heating the mixture to room temperature, the mixture was kneaded in a three-roll mill to obtain the desired grease.

Practical developer diphenylmethane-4,4'-diisocyanate-1-5,
0g to 93g mineral oil (viscosity 32.0cSt at 100°C)
) and heated to 80°C to uniformly disperse.

A mixture of 5.4 g of octadecylamine, 1.5 g of n-butylamine, and 93 g of the above-mentioned mineral oil was heated to 80 DEG C. to dissolve the mixture, and upon vigorous stirring, a gel-like substance was immediately formed. Continue stirring for approximately 30 minutes and heat to 200'C.
After heating the mixture to room temperature, the mixture was kneaded in a three-roll mill to obtain the desired grease.

Sharp carbon↓ Diphenylmethane-4,4'-diisocyanate 5.0
g to 90 g of mineral oil (viscosity 32.0 cSt at 100°C)
and then heated to 80°C to uniformly disperse the mixture.

To this was added a mixture of 3.2 g of octadecylamine, 2.0 g of n-butylamine, and 90% of the above-mentioned mineral oil, heated to 80°C and melted, and stirred vigorously to form a gel-like substance. Continue stirring for approximately 30 minutes,
After heating to C and cooling to room temperature, the mixture was kneaded in a three-roll mill to obtain the desired grease.

Diphenylmethane-4,4'-diisocyano-1-5,
0g to 71g mineral oil (viscosity 32.0cSt at 100°C)
) and heated to 80°C to uniformly disperse.

To this was added a mixture of 1.6 g of octadecylamine, 2.5 g of n-butylamine, and 71 g of the mineral oil mentioned above, heated to 80°C and dissolved, and stirred vigorously to immediately form a gel-like substance. Stirring was continued for about 30 minutes, heated to 200°C, allowed to cool to room temperature, and then kneaded in a three-roll mill to obtain the desired grease.

Diphenylmethane-4,4'-diisocyano-l-5
,0g to 91g of mineral oil (viscosity at 100°C 32.0cS
t) and heated to 80°C to uniformly disperse the mixture.

A mixture of 5.4 g of octadecylamine, 1.2 g of n-propylamine, and 91 g of the above-mentioned mineral oil was heated to 80° C. to dissolve the mixture, and upon vigorous stirring, a gel-like substance was immediately formed. Continue stirring for about 30 minutes and heat to 200°C.
The mixture was heated to room temperature and then cooled to room temperature, and then kneaded in an 8:3 roll mill to obtain the desired grease.

Fruit 1■1 diphenylmethane-4,4'-diisocyanate-1-5,
0g to 92g mineral oil (viscosity 32.0cSt at 100'C)
) and heated to 80°C to uniformly disperse the mixture.

To this, 5.4 g of octadecylamine, 0.6 g of n-propylamine, 0.8 g of n-butylamine, and the mineral oil 9
A gel-like substance was immediately formed when a mixture of 2g and 2g was heated to 80°C and dissolved, and the mixture was stirred vigorously. Stirring was continued for about 30 minutes, heated to 200°C, allowed to cool to room temperature, and then kneaded in a three-roll mill to obtain the desired grease.

Comparison ± upper diphenylmethane-4,4'-diisocyanate 5.0
g to 123 g of mineral oil (viscosity 32 at 100°C, Oc
SL) and heated to 80°C to uniformly disperse the mixture.

To this was added 10.7 g of octadecylamine and 123 g of the mineral oil.
Mix with g and heat to 80°C to dissolve, add
Vigorous stirring immediately produced a gel-like substance. Stirring was continued for about 30 minutes, heated to 200°C, allowed to cool to room temperature, and then kneaded in a three-roll mill to obtain the desired grease.

(diphenylmethane-4,4'-diisocyano-l-5,
0g to 132g mineral oil (viscosity 32.0cS at 100°C)
t) and heated to 80°C to uniformly disperse the mixture.

A mixture of 9.6 g of octadecylamine, 0.3 g of n-butylamine, and 132 g of the mineral oil was heated to 80 DEG C. to dissolve the mixture, and when the mixture was stirred vigorously, a gel-like substance was immediately formed. Continue stirring for about 30 minutes and heat to 200°C.
After heating the mixture to room temperature and cooling it to room temperature, the mixture was kneaded in a three-roll mill to obtain the desired grease.

Comparatively 7-diphenylmethane-4,4'-diisocyar 1□5.
0g to 74g mineral oil (viscosity 32.0cSt at 100°C)
) and heated to 80°C to uniformly disperse.

A mixture of 0.5 g of octadecylamine, 2.8 g of n-butylamine, and 74 g of the above-mentioned mineral oil was heated to 80 DEG C. to dissolve the mixture, and when the mixture was stirred vigorously, a shell-like substance was immediately formed. Stirring was continued for about 30 minutes, heated to 200°C, allowed to cool to room temperature, and then kneaded in a three-roll mill to obtain the desired grease.

This side 1 diphenylmethane-4,4'-diisocyano=1-10
．． 0g to 124g mineral oil (viscosity 32.0c at 100°C)
St) and heated to 80'C to uniformly disperse.

To this, 5.8 g of n-butylamine and 124 g of the above mineral oil.
Mix and heat to 80°C) and add the dissolved mixture,
Vigorous stirring immediately produced a gel-like substance. Stirring was continued for about 30 minutes, heated to 200°C, allowed to cool to room temperature, and then kneaded in a three-roll mill to obtain the desired grease.

Comparison of diphenylmethane-4,4'-diisocyanate 1□5.
0g to 571g mineral oil (viscosity 32.0cS at 100°C)
t) and heated to 80°C to uniformly disperse the mixture.

A mixture of 5.48 g of octadecylamine, 1.5 g of n-butylamine, and 571 g of the above-mentioned mineral oil was heated to 80 DEG C. to dissolve the mixture, and the mixture was stirred vigorously to immediately form a gel-like substance. Continue stirring for about 30 minutes and heat to 200°C.
After heating the mixture to room temperature and cooling it to room temperature, the mixture was kneaded in a three-roll mill to obtain the desired grease.

Diphenylmethane-4,4'-cyisocyanate 1□50
．． 0g to 138g mineral oil (viscosity 32.0c at 100°C)
St) and heated to 80°C to uniformly disperse.

To this, 53.68 g of octadecylamine, 4.6 g of n-butylamine i and 138 g of the above mineral oil were mixed and heated to 80°C.
A gel-like substance was formed immediately after heating and adding the dissolved liquid to the mixture and stirring vigorously. Continue stirring for about 30 minutes,
After heating to 00°C and cooling to room temperature, the mixture was kneaded in a three-roll mill to obtain the desired grease.

Table 1 shows the blending amounts of raw materials and the consistency and dropping point of the resulting greases in the following Examples and Comparative Examples. In addition, in the alkyl group represented by R2 and R3 in the thickener made of the siralea compound of formula (1), n
The relationship between the -butyl group content and 60W consistency is shown in FIG.

Kokogokai-7- Paraffin mineral oil (viscosity at 40°C 100.3 cSt)
) and 115 g of lithium 12-hydroxystearate were placed in a 21 stainless steel jacket, mixed, and then heated to 220°C on a heater to dissolve. In a separate container (300cc stainless steel beaker), 70g of paraffin mineral oil (same as above), 10g of dibenzylidene sorbitol, and P
A turbid dispersion of 5.0 g of AN (antioxidant) was added and the mixture was held at 220°C for 5 minutes, then poured onto a stainless steel bay and cooled. After being completely cooled to room temperature, it was kneaded in a three-roll mill to obtain a flail product of Comparative Example 7.

Next, Table 2 shows the performance of the grease obtained according to the present invention. ■ What is hair ring rotational life test? ASTM D-174
According to 1.

■ Temperature rise due to bearing rotation test is based on ASTM
Using the equipment specified in D-1741, AST
MD-1741 uses a heater to set a specified temperature condition, but in the illegal case, this heater does not perform external heating, and the temperature rise under those conditions (other conditions being the same) is caused by a thermoelectric wire in contact with the outer race. The temperature was detected by a pair and the steady-state value of the temperature was measured. At the same time, the internal grease condition and grease leakage were visually determined.

The grease obtained according to the present invention has a significantly increased hair ring life compared to a grease containing a kelizing agent.
The temperature rise in the hair ring rotation test was also the same, and it was confirmed that a single thickener showed the same or better performance.

Table 2

[Brief explanation of the drawing]

Figure 1 shows n in a thickener consisting of a diurea compound.
- It is a graph which shows the relationship between content of a butyl group and 60W efficiency. Patent applicant Kyodo Yushi Co., Ltd. Representative patent attorney Akihide Sugimura

Claims (1)

[Claims] 1. The following general formula▲There are mathematical formulas, chemical formulas, tables, etc.▼...(1) (R_1 in formula (1) is a divalent aromatic system having 6 to 15 carbon atoms. The hydrocarbon group, R_2 and R_3, represents a linear or branched, saturated or unsaturated alkyl group having 3 or 4 carbon atoms and 16 to 18 carbon atoms, and the alkyl group having 3 or 4 carbon atoms occupied in R_2 and R_3 A urea grease composition characterized in that it contains 2 to 25% by weight of a diurea compound represented by 20 to 90 mol% of base oil as a thickener, based on the base oil which is mineral oil or synthetic oil.