JPH01170690A - Urea grease composition - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] Child chestnut with raw skin The present invention relates to urea grease compositions.

In particular, it aims to extend the life of bearing grease for automobiles and steel.

Previous literature on urea grease includes, for example, Japanese Patent Publication No. 51-965, which describes a diurea thickener containing one or two aromatic nuclei and having an aliphatic group at the terminal group. Urea grease is listed. Special Public Service 1977-
Publication No. 11156 describes a urea grease containing a diurea thickener containing one aromatic nucleus and having a cyclohexyl, a C1-CI2 cyclohexyl derivative group, or a 08-C2 alkyl group at the end. Special Public Service 1987-
Publication No. 11920 discloses that the urea group has two urea groups in one molecule, and the end groups thereof are composed of aliphatic hydrocarbons, alicyclic hydrocarbons, and aromatic hydrocarbons, which are the base oil components of lubricating grease. Moreover, a urea-based grease composition having a long life at high temperatures is described, in which the groups are in the same ratio as the components constituting the base oil.

Further, US Pat. No. 4,065,395 describes a diurea grease containing a diurea thickener containing a methyl-substituted aromatic group and having a methyl-substituted or chloro-substituted aromatic group at the terminal group.

The conditions of use in automobiles, industrial machinery, etc. are from peroxidation to high temperatures,
Grease with a long life is required, and urea grease is being used in a wide range of fields. However, the problem of curing at high temperatures, which is a drawback of urea grease, is increasing, and improvements are desired.

Although urea grease is gradually being used more widely due to its excellent high temperature resistance, it often has drawbacks such as hardening at high temperatures and poor mechanical stability.

. As a result of research using various raw materials, the present invention for increasing the fortune of 7゛ has a carbon number of 3 to 8.
using an aliphatic amine with terminal alkyl groups (R1, R
3) This is based on the discovery that diurea grease with extremely excellent performance can be produced when the proportion of alkyl groups having 8 carbon atoms contained therein is 5 to 90 mol %.

That is, the grease of the present invention is characterized by good shear stability from low to high temperatures and in the presence of water, as well as extremely good lubricity and heat resistance.

That is, the present invention provides the following formula: R+NHCONHR2NHCONHR:+ (wherein R2 is an aromatic group having 6 to 15 carbon atoms, R2 and R3
represents a linear or branched, saturated or unsaturated alkyl group having 3 to 8 carbon atoms, and the proportion of the alkyl group having 8 carbon atoms in R+ and R1 is 5 to 90 mol%. ) with a diurea compound represented by 2 to 3 as a thickener to the base oil, which is mineral oil or synthetic oil.
The present invention relates to a urea grease characterized by containing 5% by weight.

Tachi-ri urea grease is usually made by reacting isocyanate with a primary amine in a lubricating oil, but by selecting the types of isocyanate and amine, greases with various properties can be made. The performance of these urea greases differs depending on the type of isocyanate and amine selected and the reaction method, but greases using diure 7 compounds as thickeners are widely used due to their good performance and ease of production. Various types of grease are produced.

The above-mentioned diurea compounds are often produced by reacting diisocyanates with primary monoamines or by reacting primary diamines with monoisocyanates, but their performance is greatly influenced by the type of end group. Diurea grease whose terminal group is an alkyl group is often inferior to diurea grease whose terminal group is an aromatic group in terms of heat resistance, oxidation resistance, water resistance, etc. As a result of various studies, the present inventors found that
We have discovered that even if the terminal group is an alkyl group, it is possible to create a diurea grease with good properties by selecting the number of carbon atoms and molecular structure of the alkyl group.

For example, let's talk about the case where diurea grease is made by reacting diisocyanate with a primary monoamine.
If an alkyl monoamine is used, the terminal group will be an alkyl group, and the alkyl monoamine has advantages such as being easily available in many types, having low toxicity, and being easy to handle. As the alkyl monoamine, a linear alkylamine or a branched alkylamine having 3 to 10 carbon atoms can be used. Particularly preferred are aliphatic amines having 3 to 8 carbon atoms, such as propylamine, butylamine, pentylamine, hexylamine, heptylamine, octylamine, and the like.

On the other hand, the diisocyanates include 2,4-tolylene diisocyanate), 2.6-)lylene diisocyanate, 2
．． 4 and 2.6-) mixture of lylene diisocyanates, diphenylmethane-4°4'-diisocyanate, 3
．． Aromatic diisocyanates such as 3'-vitricin-4,4' diisocyanate can be used.

Formula % of the present invention (wherein R2 represents an aromatic group having 6 to 15 carbon atoms, R1 and R3 represent a linear or branched, saturated or unsaturated alkyl group having 3 to 8 carbon atoms, The proportion of the alkyl group having 8 carbon atoms in R1 and R3 is 5 to 9.
0 mol%), the proportion of the alkyl group having 8 carbon atoms is 5 to 90 mol%.
However, when the proportion of alkyl groups having 8 carbon atoms is less than 5 mol%, the mixed use is ineffective, and on the other hand, when it exceeds 90 mol%, very good diurea grease can be made. This is not preferable from the viewpoint of temperature and yield.

The content of the present invention is specifically shown in Examples, but diurea grease whose terminal group is an alkyl group has the usual problems of insufficient heat resistance, poor thermosetting properties, high temperatures, and shear stability in the presence of water. Defects and other defects have been removed.

For example, diurea grease whose terminal group is an alkyl group such as an octadecyl group (C+a) has good shear stability at low temperatures, but it has poor shear stability at high temperatures and in the presence of water, and is thermosetting. It has disadvantages such as large

On the other hand, a diurea compound having a caprylyl group (C8) as a terminal group alone produces a good grease, but it lacks shear stability at high temperatures and when mixed with water.

However, even if the thickener content is the same, the consistency can be changed by changing the Cs/Cs molar ratio in the rare compound, which is a feature that makes it easy to produce grease with good performance. have.

Of course, it also has very good heat resistance, has a dropping point of 260° C. or higher, exhibits little curing phenomenon when heated to high temperatures, and has the characteristics of little oil separation at high temperatures.

It goes without saying that additives such as antioxidants, rust preventives, extreme pressure agents and anti-wear agents can be added to the grease of the present invention to improve the performance of the grease.

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

Example Diisocyanate and base oil were added to a grease pot at the mixing ratio of raw materials shown in Table 1, and heated to about 80°C. After dissolving the diisocyanate, various amines in amounts shown in Table 1 were added thereto and stirred. Although the temperature rose due to the reaction between the diisocyanate and the amine, stirring was continued in this state for about 30 minutes, and after the reaction was sufficiently carried out, the mixture was heated to 150° C. and kneaded to prepare a grease. The mineral oil shown in the examples has a viscosity of about 14 cst (100°C) and the diphenyl ether has a viscosity of about 13 cst (100°C).

Consistency, dropping point, shell roll test (
The heat curing test (room temperature, 150°C, 10%-80°C x 24 hours) is shown in Table 1.

It has been found that the shear stability at high temperatures and in the presence of water is significantly improved by using a mixture of an alkylamine having 8 carbon atoms and an alkylamine having 3 to 7 carbon atoms.

As Example 5, a grease was made with the same formulation as Example 1 and further added with an antioxidant (aromatic amine type) and a rust preventive agent (metallic organic acid salt type), and its properties were compared with commercially available diurea grease. The results are shown in Table-2.

It has been found that the grease of the present invention has extremely good heat resistance, high temperature and shear stability in the presence of water, heat hardening resistance, bearing life, etc.

The methods for measuring the properties shown in Table 1 are as follows.

Consistency: JIS K2220 Perfect score:〃 ・Water 100% shell roll: According to ASTM D 1831, 10% water was mixed with grease and a test was conducted at 80℃ x 24h to obtain 1/4 worked penetration at 25℃ (JIS K 2220).

Heat curing test: Fill 1/2 cup of the butterfly needle with grease,
The unworked penetration at 25° C. is measured after being allowed to stand for 24 hours in an air constant temperature bath at 25° C.

7/ // (hereinafter referred to as Mu) Measuring method Consistency: JIS K2220 Shell roll: ASTM D 1831 Consistency after heating at 180°C: According to JIS K2220, fill a 1/4 consistency measuring device with grease, heat at 180°C for 24 hours, and then cool. Then, measure the unworked penetration at 25°C.

Copper plate corrosion: JISK 2220 5.5B Evaporation amount:
JISK 2220 5.6B oil separation degree: JISK
2220 5.7 Wet: JISK 22205.1? Bearing life test: ASTM D 1741 Test results The effects of the present invention are as follows.

+11 Mix monoamines such as propyl, butyl, pentyl, hexyl, and peptyl groups with octylamine and react with diisocyanate to make grease. Heat resistance, shear stability from low to high temperatures, in the presence of water. Produces grease with excellent properties such as shear stability, thermosetting properties, and lubricity.

(2) The grease of the present invention is characterized by a long bearing life because it hardens less at high temperatures.

In addition, since the consistency yield is high, high consistency can be obtained with a small amount of thickener, which is considered to be effective in reducing costs.

Claims (1)

[Claims] Formula R_1NHCONHR_2NHCONHR_3 (wherein R_2 is an aromatic group having 6 to 15 carbon atoms, R_1 and R_3 are linear or branched, or saturated or unsaturated alkyl groups having 3 to 8 carbon atoms, R_1 and R_3 The proportion of the alkyl group having 8 carbon atoms in the base oil is 5 to 90 mol%) as a thickener, and contains 2 to 35% by weight of the base oil, which is mineral oil or synthetic oil. Urea grease characterized by: