JP2020139098A - Thickening agent - Google Patents

Abstract

To provide the thickening agent and a grease composition containing the same, wherein the thickening agent can enhance mechanical stability under a high shear condition and lubrication property of grease under a high temperature condition.SOLUTION: The thickening agent of the present invention is characterized by comprising an addition reaction product (C) of compound (A) having 3 to 6 active hydrogen-containing groups in one molecule and monofunctional isocyanate (B) having one isocyanate group in one molecule. The grease composition of the present invention is characterized by comprising at least one base oil selected from the group consisting of a mineral oil base oil and a synthetic oil base oil and the thickening agent.SELECTED DRAWING: None

Description

The present invention relates to a thickener and a grease containing the same.

In recent years, in various industries including automobiles, mechanical parts have become smaller, lighter, and have higher performance, and urea grease having excellent heat resistance and lubricity has been attracting attention. However, urea grease is inferior in mechanical stability and water resistance to lithium soap grease, so it often scatters and leaks from bearings, and it is known that the lubrication life can be significantly extended by improving these performances. (Patent Document 1).

Japanese Unexamined Patent Publication No. 11-241084

Currently, widely used urea-based thickeners have a urea group as an interaction segment, and it is expected that the stability will be enhanced by using a polyfunctional urea compound. However, although the polyfunctional urea compound can be produced by reacting the polyfunctional amine compound with isocyanate, it is difficult to allow the reaction to proceed uniformly, and the number of urea functional groups with the polyfunctional urea compound such as triurea or tetraurea Since low monourea compounds and diurea compounds are mixed as impurities, the problem is that the lubrication characteristics of the grease are insufficient.

The present inventor has arrived at the present invention as a result of diligent studies to solve the above problems. That is, the present invention provides an addition reaction product (C) of a compound (A) having 3 to 6 active hydrogen-containing groups in one molecule and a monofunctional isocyanate (B) having one isocyanate group in one molecule. A grease composition containing at least one base oil selected from the group consisting of a thickener, a mineral oil base oil and a synthetic oil base oil, and the thickener.

The thickener of the present invention can improve the mechanical stability of grease under high shear conditions and the lubrication characteristics under high temperature conditions.

<Thickener>
The thickener (X) of the present invention is an addition of a compound (A) having 3 to 6 active hydrogen-containing groups in one molecule and a monofunctional isocyanate (B) having one isocyanate group in one molecule. Contains the reactant (C).
The thickener in the grease is increased by agglomerating in the base oil by the interaction between the interaction segments, including the segment that ensures compatibility with the base oil and the interaction segment that is responsible for the intermolecular interaction. Acts as a filler.

The compound (A) is a compound having 3 to 6 active hydrogen-containing groups in one molecule.

The active hydrogen-containing group refers to a substituent having a hydrogen atom having a higher reactivity than a hydrogen atom bonded to a carbon atom, which is directly bonded to a nitrogen atom, an oxygen atom, a sulfur atom, etc. It is at least one group selected from the group consisting of a secondary amino group and a secondary amino group. In the present invention, a hydroxyl group and a primary amino group are preferable from the viewpoint of compatibility with the base oil.

As a compound having 3 to 6 active hydrogen-containing groups in one molecule, a polyol (A1) having 3 to 6 hydroxyl groups in one molecule, and 3 to 3 to primary amino groups or secondary amino groups in one molecule. It is a polyamine (A2) having 6 elements and a compound (A3) having 3 to 6 groups of at least 2 types selected from the group consisting of a hydroxyl group, a primary amino group and a secondary amino group in one molecule.

Among the polyols (A1) having 3 to 6 hydroxyl groups in one molecule, the trivalent polyols include glycerin, 1,2,3-butanetriol, 1,2,4-butanetriol, 1,2,3. -Pentantriol, 1,2,4-pentantriol, 2-methyl-1,2,3-propanetriol, 2-methyl-2,3,4-butanetriol, 2-ethyl-1,2,3-butane Triol, 2,3,4-pentantriol, 3-methylpentane-1,3,5-triol, 2,4-dimethyl-2,3,4-pentantriol, 2,3,4-hexanetriol, 4- Examples thereof include propyl-3,4,5-heptanetriol, 1,3,5-cyclohexanetriol, pentamethylglycerin, trimethylolethane, trimethylolpropane, castor oil and cured castor oil. Examples of the tetravalent polyol include 1,2,3,4-butanetetraol, pentaerythritol, diglycerin, sorbitan, ribose, arabinose, xylose and lyxose. Examples of the pentavalent polyol include triglycerin, arabitol, xylitol, glucose, fructose, galactose, mannose, allose, gulose, idose, talose and quercitol. Examples of the hexavalent polyol include dipentaerythritol, sorbitol, galactitol, mannitol, aritol, iditol, taritol and inositol. Examples of trivalent to hexavalent polyols include animal and vegetable fats and oils other than castor oil and hardened castor oil. The 3-hexavalent polyol may be a saccharide. Examples of saccharides include monosaccharides and the like. Among these polyols, 4- to 6-valent polyols are preferable from the viewpoint of mechanical stability, and pentaerythritol, ribose, diglycerin, xylose, triglycerin, arabitol, arabitol, xylitol, glucose, fructose, galactose, and mannitol are preferable. , Allose, Growth, Idos, Thalose, Quersitol, Ribitol, Dipentaerythritol, Sorbitol, Galactitol, Mannitol, Aritol, Iditol, Taritol, Inositol are more preferable, and those having no hemiacetal structure (sugar alcohol) are particularly preferable. Preferred examples thereof include pentaerythritol, xylitol, arabitol, arabitol, mannitol, aritol, igitol, libitol, galactitol, taritol and the like.

The 3-hexavalent polyol also includes the following alkylene oxide adducts. The alkylene oxide to be added to the polyol (hereinafter referred to as AO) is preferably an alkylene oxide having 2 to 4 carbon atoms (hereinafter abbreviated as AO), and the alkylene oxide adduct is (for example, ethylene). Oxide (hereinafter abbreviated as EO), 1,2-propylene oxide (hereinafter abbreviated as PO), 1,2-butylene oxide (hereinafter abbreviated as BO), tetrahydrofuran (hereinafter abbreviated as THF)) And so on. Of these, preferred are glycerin EO adducts, diglycerin EO adducts, triglycerin EO adducts, and trimethylolpropane, which have 1 to 10 moles of alkylene oxide added from the viewpoint of mechanical stability. EO adduct, pentaerythritol EO adduct, dipentaerythritol EO adduct, sorbitol EO adduct, glycerin EO / PO adduct, trimethylolpropane EO / PO adduct, pentaerythritol EO / PO adduct The product, the EO / PO adduct of dipentaerythritol, the EO / PO adduct of sorbitol, and the EO / THF adduct of sorbitol. Particularly preferred are pentaerythritol EO adducts and pentaerythritol EO / PO adducts. Most preferably, it is an EO adduct of pentaerythritol.

When the polyol (A1) is used, all the hydroxyl groups in the polyol can be converted into urethane groups, so that the number of hydrogen-bonding functional groups contained in each molecule can be increased as compared with the urea-based thickener. It is possible to suppress the formation of impurities generated during the synthesis of the polyfunctional urea compound of the above, and to produce a grease having excellent mechanical stability.

Of the polyamines (A2) having 3 to 6 primary amino groups or secondary amino groups in one molecule, the trivalent polyamines are 1,2,3-propanetriamine, bis (hexamethylene) triamine, and 1 , 3,5-Benzenetriamine, melamine and the like. As tetravalent polyamines, butane-1,1,4,4-tetraamine, N, N'-bis (2-aminoethyl) -1,3-propanediamine, triethylenetetramine and pyrimidin-2,4,5, Examples of the 6-tetraamine and pentavalent polyamine include tetraethylenepentamine, and examples of the hexavalent polyamine include pentaethylenehexamine. Of these, from the viewpoint of mechanical stability, polyamines containing at least three primary amino groups are preferable, 1,2,3-propanetriamine, 1,3,5-benzenetriamine, melamine, and the like. Butane-1,1,4,4-tetraamine, pyrimidine-2,4,5,6-tetraamine and the like are mentioned, and more preferably 1,2,3-propanetriamine, 1,3,5-benzenetriamine, etc. Butane-1,1,4,4-tetraamine can be mentioned.

The polyamine (A2) also contains the following alkylene oxide adducts. PO and EO are preferable as the alkylene oxide (hereinafter referred to as AO) to be added to the polyamine. The AO preferably contains only these, but other AOs may be used in combination within the range of 10% by weight or less (particularly 5% by weight or less) of the AO. Other AOs preferably have 4 to 8 carbon atoms, and examples thereof include 1,2-, 1,3-, 1,4- and 2,3-butylene oxide, styrene oxide, and the like, and two or more of them are used. May be good.

A compound (A3) having at least 3 to 6 groups of at least 2 types selected from the group consisting of a hydroxyl group, a primary amino group and a secondary amino group in one molecule is also included. The compound (A3) is an amino alcohol having both a primary amino group and a hydroxy group in one molecule, and is adrenaline, 2- (4-aminophenyl) ethanol, 2-aminobenzyl alcohol, 2-. Amino-1-phenylethanol, 4-aminobenzyl alcohol, 3-aminobenzyl alcohol, 2- (2-aminophenyl) ethanol, 2-aminoethanol, 2- (2-aminoethoxy) ethanol, tris (hydroxymethyl) amino Methane, 2-amino-2-methyl-1-propanol, 1-amino-2-propanol, 3-amino-1-propanol, 3-amino-1,2-propanediol, 2-amino-1-butanol, 1 -Amino-2-butanol, 5-amino-1-pentanol, 2-amino-1-propanol, 4-amino-1-butanol, 6-amino-1-hexanol, 1-amino-2-propanol, 2- Examples thereof include amino-1,3-propanediol, 1,3-diamino-2-propanol and valinol. From the viewpoint of affinity with the base oil, an amino alcohol having no aromatic ring is preferable, 2-aminoethanol, 2- (2-aminoethoxy) ethanol, tris (hydroxymethyl) aminomethane, 2-amino-2- Methyl-1-propanol, 1-amino-2-propanol, 3-amino-1-propanol, 3-amino-1,2-propanediol, 2-amino-1-butanol, 1-amino-2-butanol, 5 -Amino-1-pentanol, 2-amino-1-propanol, 4-amino-1-butanol, 6-amino-1-hexanol, 1-amino-2-propanol, 2-amino-1,3-propanediol , 1,3-Diamino-2-propanol, valinol and the like. More preferably, an amino alcohol having no 3-6-valent aromatic ring is preferable, and 3-amino-1,2-propanediol, 2-amino-1-butanol, 2-amino-1,3-propanediol, Examples thereof include 1,3-diamino-2-propanol and tris (hydroxymethyl) aminomethane.

The compound (A3) also includes the following alkylene oxide adducts. PO and EO are preferable as the alkylene oxide (hereinafter referred to as AO) to be added to the compound (A3). The AO preferably contains only these, but other AOs may be used in combination within the range of 10% by weight or less (particularly 5% by weight or less) of the AO. Other AOs preferably have 4 to 8 carbon atoms, and examples thereof include 1,2-, 1,3-, 1,4- and 2,3-butylene oxide, styrene oxide, and the like, and two or more of them are used. May be good.

The monofunctional isocyanate (B) is an isocyanate having one isocyanate group in one molecule and containing a hydrocarbon group having 5 to 18 carbon atoms, and the hydrocarbon group having 5 to 18 carbon atoms is used. , Pentyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group, undecyl group, dodecyl group, tridecyl group, tetradecyl group, pentadecyl group, hexadecyl group, heptadecyl group, octadecyl group, etc. Alkyl group; alkenyl group having 5 to 18 carbon atoms such as octenyl group, nonenyl group, decenyl group, undecenyl group, dodecenyl group, tridecenyl group, tetradecenyl group, pentadecenyl group; cyclohexyl group, dimethylcyclohexyl group, ethylcyclohexyl group, methylcyclohexyl Cycloalkyl group having 5 to 18 carbon atoms such as methyl group, cyclohexylethyl group, propylcyclohexyl group, butylcyclohexyl group and heptylcyclohexyl group; 6 carbon atoms such as phenyl group, naphthyl group, anthracenyl group, biphenyl group and terphenyl group. ~ 18 aryl groups; alkylaryl groups such as tolyl group, dimethylphenyl group, butylphenyl group, nonylphenyl group, methylbenzyl group and dimethylnaphthyl group; 7 carbon atoms such as phenylmethyl group, phenylethyl group and diphenylmethyl group Examples thereof include an arylalkyl group of ~ 18. In the present invention, among the above hydrocarbon groups, those having 8 to 18 carbon atoms are preferable, and those having 10 to 18 carbon atoms are more preferable, from the viewpoint of affinity with the base oil.

Examples of the monofunctional isocyanate containing the hydrocarbon group include benzyl isocyanate, 2-biphenyl isocyanate, 4-butylphenyl isocyanate, 2,6-diisopropylphenyl isocyanate, 2,6-dimethylphenyl isocyanate, and 3,5-dimethylphenyl isocyanate. , 4-Ethylphenyl isocyanate, phenethyl isocyanate, phenyl isocyanate, o-tolyl isocyanate, m-tolyl isocyanate, p-tolyl isocyanate, pentyl isocyanate, hexyl isocyanate, heptyl isocyanate, octyl isocyanate, nonyl isocyanate, decyl isocyanate, undecyl isocyanate, Examples thereof include dodecyl isocyanate, tridecyl isocyanate, tetradecyl isocyanate, pendadecil isocyanate, hexadecyl isocyanate, heptadecyl isocyanate, octadecyl isocyanate, 1-adamantyl isocyanate, cyclopentyl isocyanate and cyclohexyl isocyanate. Of these, from the viewpoint of lubricating properties, pentyl isocyanate, hexyl isocyanate, heptyl isocyanate, octyl isocyanate, nonyl isocyanate, decyl isocyanate, undecyl isocyanate, dodecyl isocyanate, tridecyl isocyanate, tetradecyl isocyanate, pendadecil isocyanate, and hexadecyl are preferable. Isocyanate, heptadecyl isocyanate, octadecyl isocyanate, 1-adamantyl isocyanate, cyclopentyl isocyanate, cyclohexyl isocyanate. More preferably, it is octyl isocyanate, nonyl isocyanate, decyl isocyanate, undecyl isocyanate, dodecyl isocyanate, tridecyl isocyanate, tetradecyl isocyanate, pendadecyl isocyanate, hexadecyl isocyanate, heptadecyl isocyanate and octadecyl isocyanate.

The addition reaction product (C) is a compound obtained by an addition reaction between the above compound (A) and isocyanate (B), and a compound represented by the following general formula (1) is preferable from the viewpoint of mechanical stability.

In the compound represented by the general formula (1), n is an integer of 0 to 10, and the values of n may be the same number or different numbers. R represents a hydrocarbon group having 5 to 18 carbon atoms. R may be the same type of group or different types of groups.

The addition reaction product (C) is an active hydrogen in the compound (A) under the condition of a reaction temperature of 60 to 100 ° C. using the compound (A) and the monofunctional isocyanate (B) as an aproton solvent or a base oil as a solvent. It is obtained by reacting a group with an isocyanate group. Specifically, the compound (A) and the monofunctional isocyanate (B) are mixed in ethyl acetate and stirred at a reaction temperature of 80 ° C. for 4 hours to obtain the corresponding addition reaction product (C). The active hydrogen compound (A) and the monofunctional isocyanate (B) are reacted under the same conditions using Eubase 4 (manufactured by SK Lubricants) instead of ethyl acetate, and then cooled to 25 ° C. to add an addition reaction product (C). ) As a thickener to obtain a grease composition.

From the viewpoint of mechanical stability, the absolute molecular weight of the addition reaction product (C) is preferably 150 to 4000, more preferably 200 to 3500, and particularly preferably 200 to 3000.

(Measurement method of absolute molecular weight)
The absolute molecular weight can be measured by the MALDI-TOF MS method.
For example, using AutoFlexII (manufactured by Brucardaltonix), measurement is performed with a nitrogen laser (337 nm) in a reflector mode and a positive ion mode. Calibration was performed using a peptide calibration standard or a protein calibration standard I (manufactured by Brucardaltonics) as a standard sample for measurement. Dislanol was used as the matrix, and sodium trifluoroacetate was used as the ionization aid.

The melting point of the addition reaction product (C) is preferably 50 ° C. or higher. Since the present invention is excellent in stability under high temperature conditions, it is more preferably 70 ° C. or higher and 150 ° C. or lower. When the above-mentioned addition reaction product (C) is produced, the larger the number of functional groups of the active hydrogen-containing group in one molecule of the compound (A), the stronger the interaction between the aggregated segments between the molecules. Can be adjusted.

As the thickener (X) of the present invention, a conventional thickener can be added in addition to the addition reaction product (C).

All kinds of thickeners that can be added to the thickener (X) of the present invention include soap-based thickeners such as metal soaps and composite metal soaps, silica gel, and non-soap-based thickeners such as urea-based thickeners. It is possible to use the agent together. Examples of the soap-based thickener include sodium soap, calcium soap, aluminum soap, lithium soap and the like, and among these, lithium soap is preferable from the viewpoint of water resistance and thermal stability. Examples of the lithium soap include lithium steerate and lithium-12-hydroxy steerate. Examples of the urea-based thickener include a urea compound, a urea-urethane compound, and a urethane compound. Examples of urea compounds, urea-urethane compounds and urethane compounds include diurea compounds, triurea compounds, tetraurea compounds, polyurea compounds (excluding diurea compounds, triurea compounds and tetraurea compounds), urea-urethane compounds, diurethane compounds or mixtures thereof. And so on.

The grease composition in the present invention contains the thickener (X) and at least one base oil selected from the group consisting of mineral oil base oils and synthetic oil base oils. In addition to these, antioxidants, rust inhibitors, metal inactivating agents, corrosion inhibitors, viscosity index improvers, which have been conventionally used in lubricating oils, as long as the object of the present invention is not impaired. Additives such as pour point depressants, detergent dispersants, emulsifiers and defoamers can be included.

<Base oil>
As the base oil in the present invention, mineral oil base oil and / or synthetic oil base oil used for metal grease can be used.

Mineral oil base oils include paraffin base oils, naphthenic base oils, and mixed base oils. These are the lubricating oil fractions obtained by atmospheric distillation of crude oil and further reduced pressure distillation, solvent removal, solvent extraction, hydrorefining, hydrocracking, solvent dewaxing, hydrodewaxing, white clay treatment, etc. It is a refined lubricating oil fraction obtained by treating with an appropriate combination of the lubricating oil refining means of the above, and can be preferably used.

The synthetic oil base oil includes esters such as monoesters, diesters and polyol esters, ethers such as polyoxyalkylene glycols, polyvinyl ethers, dialkyldiphenyl ethers and polyphenyl ethers, poly-α-olefins (PAO) and ethylene-. Examples thereof include hydrocarbon group-containing oils such as α-olefin oligomer, alkylbenzene and alkyl naphthalene.

Esters are compounds with various molecular structures, each of which has unique viscosity characteristics and low temperature characteristics, and is a base oil having a higher flash point than hydrocarbon-based base oils having the same viscosity. Esters can be obtained by dehydration condensation reaction of alcohols and carboxylic acids such as fatty acids, but in the present invention, diesters and polyols of dibasic acids and monohydric alcohols (particularly, in terms of chemical stability) A polyol ester of a neopentyl polyol) and a monohydric fatty acid or a complex ester of a polyol, a polyvalent basic acid and a monohydric alcohol (or a monohydric fatty acid) can be mentioned as a suitable base oil component.

Among the monovalent fatty acids, specific examples of linear fatty acids include butyric acid, pentanoic acid, hexanoic acid, heptanoic acid, octanoic acid, nonanoic acid, and oleic acid, and branched fatty acids include branched butyric acid. , Branched pentanoic acid, branched hexanoic acid, branched heptanic acid, branched octanoic acid, branched nonanoic acid and the like. Specifically, as fatty acids having a branch at the α-position and / or β-position, isovalic acid, 2-methylbutanoic acid, 2-methylpentanoic acid, 2-methylhexanoic acid, 2-ethylpentanoic acid, 2-methylheptanoic acid, There are 2-ethylhexanoic acid, 3,5,5-trimethylhexanoic acid and the like. As the monovalent fatty acid, a saturated fatty acid having 4 to 18 carbon atoms, preferably 6 to 12 carbon atoms can be used.

As the polyol, a polyol having 2 to 6 hydroxyl groups and a polyol having 4 to 12 carbon atoms are preferably used. Specific examples thereof include hindered alcohols such as neopentyl glycol, trimethylolethane, trimethylolpropane, trimethylolbutane, di- (trimethylolpropane), pentaerythritol, and di- (pentaerythritol).

Examples of the polyoxyalkylene glycol include polypropylene glycol, polyethylene glycol, and a copolymer of propylene oxide and ethylene oxide. Generally, a hydroxyl group at one end is etherified and the remaining end remains as a hydroxyl group, but a compound in which both ends are etherified is preferable because it has low hygroscopicity, and the skeleton has high hygroscopicity. The oxypropylene type is preferable to ethylene. In this embodiment, a polyalkylene glycol compound can be preferably used.

Among the hydrocarbon group-containing oils, poly-α-olefin (PAO) is widely used, and since it is a polymer of α-olefin, its characteristics are determined by the degree of polymerization thereof. Alkylbenzene and alkylnaphthalene are used in the field of specific lubricating oils, but there are linear type and branched type depending on the structure of the alkyl group, and they are used properly according to the purpose because their characteristics are different.

Of these base oils, mineral oils, diesters, polyol esters, polyalkylene glycol compounds or poly-α-olefins can be preferably used in the present invention. Further, in the present invention, at least one or more base oils selected from the group consisting of mineral oil base oils and / or synthetic oil base oils can be used.

The content of the base oil with respect to the total weight of the grease composition is preferably 50% by mass or more, more preferably 60% by mass or more from the viewpoint of lubrication characteristics. The content of the base oil is preferably 95% by mass or less, more preferably 90% by mass or less, based on the entire composition. Within this range, the lubricity is excellent and the grease can be stably formed.

The content of the thickener of the present invention with respect to the total weight of the grease composition is 5 to 40% by weight, preferably 10 to 40% by weight from the viewpoint of mechanical stability and lubrication characteristics.

Hereinafter, the present invention will be further described with reference to Examples and Comparative Examples, but the present invention is not limited thereto. Unless otherwise specified, parts indicate parts by weight and% indicates% by weight.

<Manufacturing of thickener and grease composition>
The thickener of the present invention can be synthesized by reacting the compound (A) with the isocyanate (B) in a base oil, and after the reaction is completed, the grease composition (Y) is obtained by cooling. By measuring the proton NMR of the obtained grease (Y), it can be confirmed that the thickener contained in the grease composition (Y) is contained.

(Manufacturing Example 1)
3924 parts of U-base 4 (manufactured by SK Lubricants) was added as a base oil to a reaction vessel equipped with a stirrer, a heating / cooling device, a thermometer and a nitrogen introduction tube, and heated to about 80 ° C. Under stirring, 136 parts of pentaerythritol was added and dissolved. Subsequently, 845 parts of dodecyl isocyanate was added and stirred for 4 hours. After the reaction, stirring was stopped and the mixture was cooled to 20 ° C. to obtain 4905 parts of the grease composition (Y-1).
In the grease composition (Y-1) (4905 parts), after reacting 136 parts of pentaerythritol with 845 parts of dodecyl isocyanate in 2000 parts in an ethyl acetate solvent, ethyl acetate was distilled off to increase the amount. It can also be obtained by isolating the thickener, dissolving it in Eubase 4 (3924 parts), which is a base oil heated to 80 ° C., and cooling to 20 ° C.
The reaction between pentaerythritol and dodecylisocyanate proceeded to produce a thickener containing a group derived from the compound. 10 mg of the obtained grease composition (Y-1) was dissolved in 2 mL of deuterated chloroform, and protons were produced. It was confirmed by measuring NMR (AVANCE III HD NanoBay 400 MHz manufactured by Bruker).

(Manufacturing Examples 2 to 5)
Grease compositions (Y-2) to (Y-) in the same manner as in Example 1 except that the type and number of parts of compound (A) and the number of parts of isocyanate (B) and base oil are changed as shown in Table 1. 5) was obtained.

(Comparative Manufacturing Example 1)
A comparative grease composition (Y'-1) composed of a tetraurea-based thickener was produced by the following method with reference to the literature (Japanese Unexamined Patent Publication No. 62-256892). 45 parts of Eubase 4 (manufactured by SK Lubricants) as base oil is added to a reaction vessel equipped with a stirrer, a heating / cooling device, a thermometer and a nitrogen introduction tube, the temperature is raised to 60 ° C. , 4- and 2,6-isomer mixture, manufactured by Tokyo Chemical Industry Co., Ltd.) 8.99 parts were added and dissolved. Next, 13.65 parts of oleylamine (manufactured by Tokyo Chemical Industry Co., Ltd.) and 1.55 parts of ethylenediamine (manufactured by Tokyo Chemical Industry Co., Ltd.) dissolved in 76 parts of Ubase 4 were added to this solution. The temperature was raised to 80 ° C., the mixture was stirred for 4 hours, and then cooled to 20 ° C. to obtain 145.19 parts of a comparative grease composition (Y'-1).

<Evaluation of physical properties of grease composition>
(Examples 6 to 10 and Comparative Example 1)
(Evaluation of consistency and mechanical stability)
The consistency and mechanical stability of the grease composition (Y-1 to Y-5) and the comparative grease composition (Y'-1) were measured based on the following test method.
Consistency: JIS K2220
Mechanical stability (shell roll test): ASTM D1831
The measurement temperature of the consistency was 25 ° C. The shell roll test was performed at 25 ° C. for 24 hours. Consistency was measured before and after the shell roll test, and the measurement results are shown in Table 2. The smaller the increase in consistency before and after the shell roll test, the better the mechanical stability of the grease.

(Stability evaluation at high temperature)
The maximum non-seizure load was measured and evaluated in order to evaluate the stability of the grease composition (Y-1 to Y-5) and the comparative grease composition (Y'-1) under high temperature conditions. The measurement was carried out based on the following test method. Shell-type 4-ball load-bearing performance test: The sample temperature at the time of measurement was measured at 30 ° C. (low temperature) and 100 ° C. (high temperature) for each sample, but the test was carried out in accordance with ASTM D 2596.
Table 3 shows the measurement results of the maximum non-seizure load performed by the above method. The larger the maximum non-seizure load, the better the lubrication characteristics of the grease composition.

Since the thickener of the present invention has the effect of improving the mechanical stability of grease under high shear conditions and the lubrication characteristics under high temperature conditions, it can be suitably used as a thickener.

Claims (6)

A thickener containing an addition reaction product (C) of a compound (A) having 3 to 6 active hydrogen-containing groups in one molecule and a monofunctional isocyanate (B) having one isocyanate group in one molecule (C). X). The thickener according to claim 1, wherein the compound (A) is a polyol (A1) or a polyamine (A2). The thickener according to claim 1 or 2, wherein the compound (A) has an oxyalkylene group. The thickener according to any one of claims 1 to 3, wherein the addition reaction product (C) is represented by the following general formula (1).

[N in the general formula (1) is an integer from 0 to 10, and n may be the same number or a different number. R represents a hydrocarbon group having 5 to 18 carbon atoms, and R may be a group of the same type or a group of a different type. ] The grease composition (Y) containing at least one base oil selected from the group consisting of mineral oil base oils and synthetic oil base oils and the thickener according to any one of claims 1 to 4. The grease composition according to claim 5, which contains 5 to 40% by weight of the thickener according to any one of claims 1 to 4 with respect to the total weight of the grease composition.