JPS60231797A - Urea grease composition - Google Patents

Abstract

PURPOSE:To provide a urea grease compsn. with excellent thermosetting property, prepd. by adding a specified diurea compd. as thickener to a base mineral or synthetic oil. CONSTITUTION:A diurea compd. of the formula (where R2 is a 1-15C aromatic group; R1 and R3 are a 6-12C aromatic group or a furfuryl group, with the furfuryl group accounting for 5-90mol% in R1 and R3) is added as thickener to a base mineral or synthetic oil in an amt. of 2-35wt%. The diurea compd. is obtained, e.g., from an aromatic diisocyanate and a primary monoamine. The aromatic diisocyanates (R2) are, e.g., 2,4-tolylene diisocyanate and 2,6-tolylene diisocyanate. The amine (R1 and R3) includes aromatic amine such as aniline and benzylamine and heterocyclic monoamine such as furfurylamine.

Description

[Detailed description of the invention] Urea grease has a long life at high temperatures due to its excellent heat resistance and oxidation resistance, and its other properties such as lubricity and water resistance are also excellent, so its use is gradually expanding. ing. Grease is required not only to have good lubricity but also to have heat resistance as the operating conditions become more severe.
There are also increasing demands for temperatures exceeding 0°C.

Conventional technology Compared to conventional greases that use metal soaps as thickeners, such as Li-soap-based greases, Veralea grease has a higher dropping point (and because it does not contain metal soaps that act as oxidation catalysts, it has been used as a grease with good oxidation resistance. However, their use in the market was limited because they tended to harden at high temperatures and sometimes had shortcomings such as poor shear stability. The performance of urea grease has been reviewed as the temperature at which grease is used becomes higher and longer-life greases are increasingly desired.
Its uses have expanded.

Conventionally, as for literature related to urea grease, for example, Japanese Patent Publication No. 51-965 describes urea glylohexyl, which contains a diurea thickener containing one or two aromatic nuclei and has an aliphatic group at the end; C? Ct*cyclohexyl derived group or C, -C,. A urea grease containing a diurea thickener having an alkyl group is described, and is composed of aliphatic hydrocarbons, alicyclic hydrocarbons, and aromatic hydrocarbons, which are the base oil components of the grease. A high-temperature, long-life urea-based grease composition is described that has a K ratio equal to that of the components constituting the base oil. Also described is a diurea grease containing a diurea thickener having a Group Group group group.

Problems to be Solved by the Invention The main purpose of the present invention is to improve the thermosetting property of urea grease, which has been considered a drawback in the past.As a result of research into urea grease, which has a long grease life at high temperatures, it has been found that the urea grease has extremely good properties. We were able to develop urea grease with excellent performance.

Urea grease is sometimes made by preparing a urea compound in a suitable solvent and dispersing it in a base oil, but it is usually made by reacting an incyanate and a primary amine in a lubricant base oil. often made. Various types of urea grease can be made by selecting the types of isocyanates and amines used as raw materials, but the performance of the grease varies depending on the types of isocyanates and amines selected and the reaction method. The so-called zourea grease, which uses a diurea compound with two urea bonds as a thickener, has good performance (and is easy to manufacture, so many products are produced.Diurea compounds are often composed of diisocyanates and primary monoamines). or by the reaction of a monoisocyanate with a primary diamine.The performance of diurea grease is expressed by the formula R, NHCONHR.
,NHCONH,R, of the zorea compound R1
Although the influence of the groups is large, the influence of the terminal groups R1 and R3 when the R3 groups are the same is also extremely large. For example, when a diurea compound is produced by reacting a diisocyanate with a primary monoamine, the terminal groups R8 and R8 are determined by the type of monoamine selected. If an alkylamine is used as the monoamine, the terminal group will be an alkyl group, if an aromatic monoamine is used, the terminal group will be an aromatic group, and if a heterocyclic monoamine is used, the terminal group will be a heterocyclic group. Diurea grease, which uses a diurea compound with an alkyl group as a terminal group, has good performance depending on the selection of the alkyl group, but it is slightly heat resistant compared to diurea grease with an aromatic group as a terminal group. It is often inferior to

On the other hand, greases made of diurea compounds with aromatic groups as terminal groups exhibit extremely excellent heat resistance, have a very long grease life at high temperatures, and often have excellent thermosetting properties and water resistance. However, diurea compounds whose terminal groups are aromatic groups generally have good thickening effects (although it is often impossible to make hard grease without using a large amount of thickener).

The present invention relates to a diurea grease containing a diurea compound having a heterocyclic furfuryl group or a substituted furfuryl group and an aromatic group (R1 and R8 groups) as a thickener. The diurea grease of the present invention has good consistency, good yield, very good heat resistance and oxidation resistance, and exhibits a very long high temperature life.

That is, the formula R, NHCONHR, NHCONHR.

(In the formula, R1 is an aromatic group having 6 to 15 carbon atoms, R8 and R3 are a substituted or unsubstituted aromatic group having 6 to 12 carbon atoms, and a substituted or unsubstituted furfuryl group, and %R
The proportion of the furfuryl group in R3 and R3 is 5 to 90 molti) as a thickener, and contains 2 to 35% by weight of the base oil, which is mineral oil or synthetic oil. It is a urea grease.

For example, in the case where the zourea grease of the present invention is made using an aromatic diisocyanate and a primary thinoamine, the aromatic diisocyanate (R1) is 2.4-)lylene diisocyanate), 2. 6-1-lylene diisocyanate, mixture of 2,4- and 2,6-)lylene diisocyanates, diphenylmethane-4,4
'w diisocyanate, 3,3'-vitrylene-4°4'-diisocyanate, etc. can be used. Aromatic amines (Rt+Rs) include aniline, toluidine,
Xylidine, benzylamine, chloroaniline, aminopiphenyl, etc. can be used. Also, heterocyclic monoamines (Rt.

As Rs ), furfurylamine, alkyl-substituted or halodane-substituted furfurylamine, or the like can be used. Furfurylamine or substituted furfurylamine, which is a heterocyclic monoamine, is used in a proportion of 5 to 90 mole based on the total amount of monoamines (the total of R1 and R1). Although furfurylamine or substituted furfurylamine alone reacts with the diisocyanate to produce a good dicrea grease, it exhibits particularly good performance when combined with the aromatic monoamine. In other words, the urea grease made from the IMK of the present invention has a better consistency yield than when an aromatic monoamine is used alone, and the grease can be made effectively and easily by using a small amount of thickener. . In addition, the urea grease of the present invention has extremely good heat resistance,
It has the characteristics of a high dropping point under extreme pressure and an extremely long grease life at high temperatures. Furthermore, the grease according to the invention has a 180
It has a small tendency to harden even at high temperatures above ℃, and has far superior heat curability compared to currently commercially available urea greases. The urea grease of the present invention has excellent performance such as lubricity, shear stability, and water resistance, and it is extremely effective in all performance points by adding appropriate additives such as antioxidants and rust inhibitors. Can make grease with good performance.

The present invention will be explained below with reference to Examples.

Example: Diisocyanate and base oil were added to a grease pot in the proportions shown in Table 1 and heated to about 80°C to dissolve the diisocyanate, followed by adding the amount of amine shown in Table 1. Stir. The reaction between the diisocyanate and the amino acid proceeded rapidly, and the temperature rose due to the heat of reaction, but after continuing stirring in this state for about 30 minutes, the mixture was heated to about 150" CK and kneaded to make a grease. The mineral oil shown has a viscosity of 1
The silicone oil has a viscosity of 35 cst (100°C).

Grease consistency, dropping point and oil separation (180
℃, 24 hours) are shown in Table 1.

(>-1-O-Mimeji) From Table 1, it was found that when furfurylamine was used, a grease with excellent high temperature resistance could be obtained with a smaller amount of thickener.

Further, a grease was prepared by adding additives such as an antioxidant and a rust preventive to the grease of Example 6 (Example 10), and the results of comparison with commercially available urea grease are shown in Table 2. It has been found that the grease of the present invention has excellent performance at high temperatures, such as an extremely long service life at high temperatures and very little thermosetting.

Effect of invention The effects of the present invention are as follows.

(1) The urea grease of the present invention has extremely good heat resistance, an extremely high dropping point, and an extremely long grease life at high temperatures.

(2) The urea grease of the present invention has a small tendency to harden even at high temperatures of 180° C. or higher, and has significantly superior heat curability compared to currently commercially available urea greases.

(3) The urea grease of the present invention also has excellent performance in terms of lubricity, shear stability, water resistance, etc., and by adding appropriate additives such as antioxidants and rust preventives, it can achieve extremely excellent performance in all aspects. It is possible to make grease.

Agent: Masao Miyake and 1 other person Continuation of page 1 @Inventor - Tetsuo Maru Higashi J

Claims (1)

[Claims] (1) Formula % Formula % (wherein R2 is an aromatic group having 6 to 15 carbon atoms, R1 and R8 are aromatic groups having 6 to 12 carbon atoms with or without a substituent, and A furfuryl group having or having no substituent, "1 and Rs
The ratio of the furfuryl groups in the base oil is 5 to 90 molt) using a diurea compound represented by 2 to 35 molt to the base oil which is mineral oil or synthetic oil.
A urea grease composition characterized in that it contains % by weight.