KR20140107557A - Grease composition - Google Patents

Abstract

The present invention relates to a grease composition having a high abrasion resistance comprising a base oil, a thickener and a poly (meth) acrylate derivative.

Description

Grease composition {GREASE COMPOSITION}

The present invention relates to a grease composition, more particularly a grease composition having a high abrasion resistance.

Sliding parts and rotating parts of machines require some type of lubrication substrate in which lubricating oil or grease can be combined with many machines that use a grease lubrication system which can simplify the sealing structure and make the equipment smaller and denser It is usually used. The range of use can be varied, for example, including various types of ball-and-roller bearings and sliding bearings that assist in the rotation of the body, and also sliding parts or chains of ball joints and links, booms of gear wheels, And the required quality is rising every year with the maintenance work, which is a common task on all machines, and extended machine life.

In addition, due to recent developments in mechanical technology, material technology and precision machining, fatigue failure and damage to materials have become very low, and the machine life has been greatly influenced by the performance of the lubricating oil or grease. Therefore, the improvement of the lubrication characteristics of the grease and the solving of the problems related thereto can contribute greatly to the enhancement of the quality and reliability of the machine, and are thus very important.

Specifically, when the lubrication performance of the grease in the rotating parts or sliding parts of the machine is lowered and the machine life is shortened, there can be roughly divided into two. First, the grease is oxidized when used at high temperatures, resulting in solidification of the grease due to evaporation and thermal polymerization of the oil components or failure of the grease structure with the formation of organic acids or aldehydes, resulting in lubrication failure. Secondly, as a result of significant sliding wear on the machine sliding surface during use at relatively low speeds under high loads or at high speeds, boundary lubrication conditions tend to occur and the lubricating film of the grease becomes extremely thin, Metal contact occurs and abrasion increases, resulting in damage such as metal separation or seizure.

A method for overcoming the situation described in the first case is to use a thickener or base oil as a grease component that effectively incorporates an antioxidant suitable for grease (see Japanese Patent No. 2085136) or undergoes some structural or chemical change due to heat, Thereby improving the overall function of the grease and aiming at extending the machine's sleep by extending the machine life. Urea-based greases are an example of thermally stable thickeners, and there have been many technological advances recently using the thickeners (see Japanese Patent No. 4769456). It has a higher dropping point than the grease with lithium soap as a thickener, thus its thermal stability and also its abrasion resistance and lubricity, and urea grease is used in a wide range of fields. For example, in the automotive industry, the heat resistance, abrasion resistance and friction characteristics associated with various types of automotive parts such as CVJ (constant velocity joint), electric power steering, alternator bearing and wheel bearing, There are many cases in which the excellent performance of the urea grease and the additive technology are applied.

Also, since automobiles are used everywhere in the world, the grease used in automotive parts is extremely cold at about -40 DEG C and also at high temperatures above 100 DEG C (heat radiated from the engine compartment + heat radiated from the road surface) Designed and manufactured in consideration of its use, and also obtains low stabilization torque characteristics over a wide temperature range from low temperature to high temperature, and does not exhibit deficient oiling due to a drop in viscosity at high temperatures, Grease with a long service life is required.

To improve low temperature properties, methacrylate polymers are incorporated into synthetic hydrocarbon oils (poly-alpha-olefins), ester type base oils or glycol type base oils with excellent low temperature fluidity as grease base oils, A technique requiring improvement is disclosed (see JP-A-2006-77119).

A method for overcoming the situation described in the second case is a method in which the viscosity of the grease base oil is increased and the polymer or other viscosity improver is incorporated so that the lubricating film is thickened and the metal / metal contact is suppressed (JP- To 69282), and an anti-wear agent, extreme pressure agent, solid lubricant or other load-resistant additive is incorporated into the grease such that the chemical or physical action of such additive causes the coating or solid film to adhere between the sliding surface and the surface protected thereby (See Japanese Patent Nos. 3833756 and JP-A-2-18497). However, according to the type of additive, the structure of the grease can be changed and there are also many additives which adversely affect the mechanical parts. For example, high acid value thiophosphates have the disadvantage of easily reacting with the free alkali of the soap-based grease, and olefin sulfide type additives can cause curing of the urea grease over time. Also, in the case of additives with strong chemical activity, there are many issues, such as the discoloration or corrosion of metals, and the strength of the sealing material such as nitrile, acrylic or urethane rubber is reduced.

Thus, in terms of grease lubrication, the ability to hold a suitable oil film and to form an adsorbed film on a lubricating sliding surface that does not have any adverse effect on the grease structure is advantageous in terms of both quality stabilization of automotive and industrial components, and also It is very effective in terms of ensuring reliability and extending the realized machine life.

The present invention relates to the problem of providing a grease composition with high abrasion resistance. As a result of intensive studies on this background, the present inventors have found that by using a poly (meth) acrylate derivative containing a hydroxyl group, the abrasion resistance of the grease can be increased, thereby solving the above-mentioned problem.

Accordingly, the present invention provides a grease composition characterized in that, in a grease composition containing a base oil and a thickener, a poly (meth) acrylate derivative containing a hydroxyl group as an additive is used.

The grease composition according to the present invention exhibits the effect of higher abrasion resistance compared to conventional grease compositions.

The grease composition of this embodiment contains the essential components "base oil "," thickener ", and additives. In the following, the individual components contained in the grease composition, the amount of the components in the grease composition The manufacturing process, the properties of the grease composition and the application of the grease composition are consequently described.

The base oil used in the grease composition of this embodiment of the present invention is not particularly limited. For example, mineral oils, synthetic oils, animal / vegetable oils and mixtures thereof used in common grease compositions may suitably be used. As a specific example, base oils belonging to Group I, Group II, Group III and Group IV of the API (US Petroleum Institute) base oil category can be used as such or in the form of mixtures.

Group I base oils include, for example, paraffinic mineral oils obtained by applying a suitable combination of purification methods such as solvent purification, hydro-purification and dewaxing to the lubricating oil fraction obtained by atmospheric distillation of crude oil do. Group II base oils include, for example, paraffinic mineral oils obtained by applying a suitable combination of purification methods such as hydro-cracking and dewaxing to the lubricating oil fraction obtained by atmospheric distillation of crude oil. Hydrogenation-purification methods such as Gulf Co. Group II base oil prepared by the process has a total sulfur content of less than 10 ppm and an aromatic content of less than 5% and can be preferably used in the present invention. Group III base oils and Group II + base oils are, for example, paraffinic mineral oils prepared by applying lubricating oils obtained by atmospheric distillation of crude oils to high levels of hydrogenation-purification, and also waxes Base oils purified by an isodeprecipitation process in which they are converted to isoparaffins, and base oils made by the Mobil Wax Isomerization Process, which may also be preferably used in the manner of the present invention .

Examples of synthetic oils are polyolefins, diesters of dibasic acids such as dioctyl sebacate, polyol esters, alkylbenzenes, alkylnaphthalenes, esters, polyoxyalkylene glycols, polyoxyalkylene glycol esters, polyoxyalkylene glycol ethers, Polyphenyl ether, dialkyl diphenyl ether, fluorine-containing compounds (perfluoropolyether, fluorinated polyethylene, etc.), silicon and the like. The above-mentioned polyolefins include various types of olefin polymers and also their hydrogenation products. Any olefin may be used, and examples thereof include ethylene, propylene, butene, and? -Olefin having 5 or more carbon atoms. In the production of polyolefins, a single type of the above-mentioned olefins may be used per se, or a combination of two or more types may be used. Particularly, from the viewpoint of improving low-temperature fluidity and low-temperature lubricity, polyolefins represented by poly-a-olefin (PAO) synthetic oils are preferred, which are IV base oil. When the viscosity index of the poly-α-olefin synthetic oil is high, the viscosity is slightly lowered at a high temperature, the ability to retain the oil film is high, the viscosity is not excessively increased at a low temperature and a suitable fluidity is maintained, Down. When this excellent low temperature behavior is used in grease base oil, it works very effectively. For example, when a lubricating oil having a very high viscosity at low temperatures and thus loss of fluidity is used as the grease base oil, the lubricity of the grease is completely damaged and there is virtually no supply of lubricating oil to the sliding surfaces of the machine parts On the other hand, when using a grease containing a base oil having excellent low-temperature fluidity, such as a poly-alpha-olefin synthetic oil, lubricating oil can be appropriately supplied to the sliding surface without lubrication loss, Function is maintained and wear is suppressed.

The oil obtained by the GTL (gas to liquid) process, which is an oil synthesized from natural gas in a liquid fuel conversion technology using the Fischer Tropsch method, is obtained by purification of the crude oil It has an extremely low sulfur content and an aromatic component content as compared to the obtained mineral oil base oil and has a very high paraffin structure ratio resulting in excellent oxidation stability and extremely low evaporation loss, May be used as preferred.

The thickening agent used as an essential component in the process of the present invention is not particularly limited and may be of the type used in conventional grease compositions. Examples are urea-type thickeners, metal soaps, complex soaps, organically modified bentonites and silicas. Examples of urea-based thickeners are aliphatic diureas, alicyclic diureas, aromatic diureas, triurea, tetraurea and urea-urethanes. Examples of the metal soap include lithium 12-hydroxystearate, lithium stearate, calcium 12-hydroxystearate, calcium stearate, lithium complex, calcium complex, barium complex, aluminum complex, and lithium-calcium mixed soap. An example of an organo-bentonite is montmorillonite treated with a quaternary ammonium salt. Examples of silica are ultrafine silica powders prepared by a gas phase reaction, or ultrafine silica powders after surface treatment with a lower alcohol such as methanol. Other examples include sulfonate complexes, polytetrafluoroethylene, tribasic calcium phosphate, and the like.

Among these, preferred thickeners are urea compounds formed by reaction between isocyanates and primary amines. The urea compound may be, for example, diurea, triurea, tetraurea, pentaurea or hexaurea, which may be an aliphatic urea, an aliphatic urea or an aromatic urea, which may also have other groups such as a urethane group (As in the case of urea-urethane).

For example, a diurea thickener is obtained by reaction between 1 mol of a diisocyanate and 2 mol of a primary monoamine. Tetraurea thickeners are also obtained, for example, by reaction between 2 mol of diisocyanate and 1 mol of primary diamine plus 2 mol of primary monoamine. The triurea-mono-urethane thickener is also obtained, for example, by reaction between 2 mol of diisocyanate and 1 mol of primary diamine + 1 mol of primary monoamine and 1 mol of monoalcohol. In the following, examples of various starting materials used in the synthesis of such urea compounds are given.

In the case of diisocyanates, aliphatic diisocyanates, alicyclic diisocyanates and aromatic diisocyanates are exemplified. More specific examples are 4,4'-diphenylmethane diisocyanate (MDI), tolylene diisocyanate (TDI), naphthalene diisocyanate, p-phenylene diisocyanate, trans-1,4-cyclohexane diisocyanate (CHDI) (Isocyanatomethyl-benzene), 4,4'-dicyclohexylmethane diisocyanate (H12MDI), 1,3-bis (isocyanatomethyl) -cyclohexane (H6XDI) , Hexamethylene diisocyanate (HDI), 3-isocyanatomethyl-3,3,5'-trimethyl-cyclohexyl isocyanate (IPDI), phenylene diisocyanate, m-tetramethyl xylene diisocyanate (MDI), tolylene diisocyanate (TDI), trans-1,4-cyclohexane diisocyanate (p-TMXDI) (CHDI) and 4,4'-dicyclohexylmethane diisocyanate (H12MDI).

The primary monoamine may be an aliphatic, alicyclic or aromatic monoamine. An aliphatic amine, a branched or straight-minutes, but the number of C ₈ to C ₂₄ saturated or unsaturated aliphatic amine can be used in swaeil, preferred are straight-chain aliphatic amines. Specific examples of primary monoamines include octylamine, decylamine, dodecylamine, tetradecylamine, hexadecylamine, octadecylamine, oleylamine, aniline, p-toluidene, and cyclohexylamine.

The primary diamine may be an aliphatic, alicyclic or aromatic diamine. Examples include C ₂ to C ₁₂ diamines such as aliphatic diamines such as ethylenediamine, trimethylenediamine, tetramethylenediamine, hexamethylenediamine, octamethylenediamine and decamethylene-diamine, alicyclic diamines such as diaminocyclohexane and aromatic diamines such as phenylene Diamine, benzidine, diaminostilbene, and tolidine.

The monoalcohol may be an aliphatic, alicyclic or aromatic alcohol. As the aliphatic monoalcohol herein, a branched or straight-number is C ₈ to C ₂₄ saturated or unsaturated aliphatic alcohols may be used in swaeil, but the straight chain alcohols are preferred.

Specific examples include octyl alcohol, decyl alcohol, dodecyl alcohol, tetradecyl alcohol, hexadecyl alcohol, octadecyl alcohol and oleyl alcohol, while examples of alicyclic alcohols include cyclohexyl alcohol, examples of aromatic alcohols include benzyl Alcohol, salicyl alcohol, phenethyl alcohol, cinnamyl alcohol, and hydrocinnamyl alcohol.

Particularly preferred are alkyldiureas, more preferably compounds represented by the formula (I)

R ¹ -NHCONH-R ² -NHCONH-R ³ (I)

(Wherein R ¹ and R ³ each represent a C _8-12 aliphatic hydrocarbon group and R ² represents a C _6-152 aromatic group). Here, R ¹ and R ³ are, independently of each other, an 8-carbon octyl group or a 12-carbon lauryl group. Also, R ² is preferably a diphenylmethane group. In a more preferred embodiment, a compound wherein R ² is a diphenylmethane group, (1) R ¹ and R ³ are 8-carbon octyl groups, (2-1) R ¹ and R ³ are each an 8- ¹ and R ³ mixture of lauryl resulting compound la is a 12-carbon, (2-2) R ¹ or R ³ is 8-carbon-octyl group, while R ¹ and R ³ of the other due to the 12-lauryl carbon compound, and ( 2-3) The compound of (2-1) and the compound of (2-2), or a mixture of both, is used. Among them, (2-1) to (2-3) are particularly preferable.

In the grease composition of the method of the present invention, another thickener may be jointly used with a major thickener (which is, for example, the urea compound mentioned above (e.g. alkyldiurea)). Thus, when a urea compound is used as the main thickener, such other thickener may be selected from the group consisting of tribasic calcium phosphate, an alkali metal soap, an alkali metal complex soap, an alkaline earth metal soap, an alkaline earth complex soap, an alkali metal sulfonate, an alkaline earth metal sulfonate, Other metal soaps, metal terephthalate salts, clays, silica airgel or other types of silicas (silicon oxides) or fluoropolymers such as polytetrafluoroethylene, etc., either of which may be used as such or two Or more can be used in combination. Likewise, any material capable of imparting a viscosity synergistic effect may also be used.

The additive used as an essential component in this embodiment is a poly (meth) acrylate containing a hydroxyl group. Such poly (meth) acrylates containing hydroxyl groups are copolymers, copolymers based on alkyl (meth) acrylates having C _1-20 alkyl groups, and hydroxyl-group-containing vinyl monomers as essential constituents thereof As component monomers.

Specific examples of the above-mentioned alkyl (meth) acrylate (a) having a C _1-20 alkyl group are as follows:

(a1) Alkyl (meth) acrylates having a C _1-4 alkyl group: Examples thereof include methyl (meth) acrylate, ethyl (meth) acrylate, n- or isopropyl (meth) - or sec-butyl (meth) acrylate,

(a2) Alkyl (meth) acrylates having C _8-20 alkyl groups: Examples thereof include n-octyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, (Meth) acrylate, n-decyl (meth) acrylate, n-decyl (meth) acrylate, (Meth) acrylate, n-pentadecyl (meth) acrylate, 2-methyltetradecyl (meth) acrylate, N-hexadecyl (meth) acrylate, n-octadecyl (meth) acrylate, n-eicosyl (meth) acrylate, n-docosyl (meth) acrylate, Dovanol 23 [manufactured by Mitsubishi Chemical Corp. A mixture of C ₁₂ / C ₁₃ oxo-alcohol] methacrylate and Dovanol 45 [Mitsubishi Chemical Corp. The production by the C ₁₃ / C ₁₄ oxo-alcohol mixture; methacrylate deungim,

(a3) Alkyl (meth) acrylates having a C _5-7 alkyl group: Examples thereof include n-pentyl (meth) acrylate and n-hexyl (meth) acrylate.

Among the above-mentioned (a1) to (a3), monomers belonging to (a1) and (a2) are preferable, and those belonging to (a2) are more preferable. In terms of solubility in the base oil, it is preferable that the monomer of (a2) has 10 to 20 carbons in the alkyl group and more preferably 12 to 14 carbons in the monomer.

The above-mentioned hydroxyl-group-containing vinyl monomer (b) in which the copolymer is constituted with an alkyl (meth) acrylate having a C1-20 alkyl group may be produced by reacting one or more (preferably one or two) Is a vinyl monomer. Specific examples are:

(b1) hydroxyalkyl (C _2-6 ) (meth) acrylate:

(Meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2- or 3-hydroxypropyl (meth) acrylate, 2-hydroxybutyl Rate, etc.,

(b2) mono- or di-hydroxyalkyl (C _1-4 ) -substituted (meth) acrylamide:

(Meth) acrylamides such as N, N-dihydroxymethyl (meth) acrylamide, N, N-dihydroxypropyl (meth) acrylamide,

(b3) vinyl alcohol (formed by hydrolysis of vinyl acetate units),

(b4) C _3-12 alkenol:

(Meth) allyl alcohol, crotyl alcohol, isocrothyl alcohol, 1-octanol, 1-undecene,

(b5) C _4-12 alkenediols:

Butene-1-ol, 2-butene-1,4-diol and the like,

(b6) hydroxyalkyl (C _1-6 ) alkenyl (C _3-10 ) ether:

Such as 2-hydroxyethylpropenyl ether,

(b7) Hydroxyl-group-containing aromatic monomer:

Such as o-, m- or p-hydroxystyrene,

(b8) Polyhydric alcohol (3- to 8-valent):

(C _3-10 ) ether or (meth) acrylate, such as, for example, alkane polyols and their intramolecular or intermolecular dehydro-condensates and sugars (for example, glycerol, pentaerythritol, sorbitol, sorbitan, diglycerol or sucrose) (E.g., sucrose (meth) allyl ether) and the like,

(b9) a vinyl monomer containing a polyoxyalkylene chain and hydroxyl group (s):

(C _2-4 alkylene group: a degree of polymerization of 2 to 50) or a polyoxyalkylene polyol (the above-mentioned 3- to 8-valent alcohol (C _2-4 alkyl group; Mono (meth) acrylate or poly (propylene glycol) mono (meth) acrylate of polyethylene glycol (polymerization degree of 2-9) mono (meth) acrylate of polyoxyalkylene ether (Meth) acrylate, polyethylene glycol (polymerization degree of 2-30) mono (meth) allyl ether}, and the like.

It is also possible to copolymerize the above-mentioned monomers (a) and (b) with other monomers in the above-mentioned poly (meth) acrylate copolymers containing hydroxyl groups, for example, a monomer containing a nitrogen atom (c ) Can be used. Specific examples thereof are as follows:

(c1) nitrogen-containing group-containing monomers such as 4-nitrostyrene,

(c2) a vinyl monomer containing a primary, secondary or tertiary amino group; Examples of this are:

(c2-1) a vinyl monomer containing a primary amino group; For example, C _3-6 alkenyl amine [(meth) allyl amine, crotyl amine, etc.], amino-alkyl (C _2-6) (meth) acrylates [amino ethyl (meth) acrylate, etc.],

(c2-2) a vinyl monomer containing a secondary amino group; (Meth) acrylates such as alkyl (C _1-6 ) aminoalkyl (C _2-6 ) (meth) acrylates such as tert-butylaminoethyl methacrylate and methylaminoethyl (meth) acrylate, diphenylamine (Meth) acrylamides, etc.), C _6-12 dialkylamines [such as di (meth) allylamine], and the like;

(c2-3) vinyl monomers containing a tertiary amino group; For example a dialkyl (C _1-4) - amino-alkyl (C _2-6) (meth) acrylate [dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate], dialkyl (C _{1 4} ) aminoalkyl (C _2-6 ) (meth) acrylamide [dimethylaminoethyl (meth) acrylamide, diethylaminoethyl (meth) acrylamide, dimethylaminopropyl- An aromatic vinyl monomer containing a cha-amino group [such as N, N-dimethylaminostyrene, etc.]

(c2-4) A vinyl monomer containing nitrogen

Vinylpyrrolidone, N-vinylpyrrolidone, N-vinylthiopyrrolidone, and the like], a heterocyclic compound (such as morpholinoethyl (meth) acrylate,

(c3) an amphoteric vinyl monomer; Examples of this are:

N- (meth) acryloyloxy (or amino), alkyl (C _1-10), N, N- dialkyl (C _1-5) alkyl ammonium -N- (C _1-5) carboxylate (or sulfate ), Such as N- (meth) acryloyloxyethyl N, N-dimethylammonium N-methylcarboxylate, N- (meth) acryloylaminopropyl N, N-dimethylammonium N-methylcarboxylate and N - (meth) acryloyloxyethyl N, N-dimethylammonium propylsulfate and the like; And

(c4) Monomers containing a nitrile group, such as (meth) acrylonitrile.

Another example of the copolymerizable monomer is an aliphatic hydrocarbon-type vinyl monomer (d). Examples thereof include C _2-20 alkenes [ethylene, propylene, butene, isobutylene, pentene, heptene, diisobutylene, octene, dodecene, octadecene etc.] and C _4-12 alkadienes [butadiene, isoprene, , 4-pentadiene, 1,6-heptadiene, 1,7-octadiene, etc.].

Again there is an alicyclic hydrocarbon-type vinyl monomer (e): examples thereof include cyclohexane, (di) cyclopentadiene, pinene, limonene, indene, vinylcyclohexene and ethylidenebicycloheptene.

There are also aromatic hydrocarbon-type vinyl monomers (f): examples thereof include styrene,? -Methylstyrene, vinyltoluene, 2,4-dimethylstyrene, 4-ethylstyrene, 4-isopropylstyrene, 4-phenylstyrene, 4-cyclohexylstyrene, 4-benzylstyrene, 4-crotylbenzene and 2-vinylnaphthalene.

Vinyl esters (vinyl acetate, vinyl propionate, vinyl butyrate, vinyl octanoate, etc.) of saturated C _2-12 fatty acids, C _1-12 alkyl, aryl or alkoxyalkyl vinyl ethers [such as methyl vinyl ether, ethyl vinyl ether, propyl vinyl ether, butyl vinyl ether, 2-ethylhexyl vinyl ether, phenyl vinyl ether, vinyl 2-methoxyethyl ether, vinyl 2- Butoxyethyl ether, etc.] and C _1-8 alkyl or aryl vinyl ketone [methyl vinyl ketone, ethyl vinyl ketone, phenyl vinyl ketone, etc.].

There are also esters (h) of unsaturated polycarboxylic acids: examples thereof include alkyl, cycloalkyl and aralkyl esters of unsaturated polycarboxylic acids, especially unsaturated dicarboxylic acids [such as maleic acid, fumaric acid and itaconic acid] C _1-8 alkyl di-esters such as dimethyl maleate, dimethyl fumarate, diethyl maleate and dioctyl maleate.

(I): Examples thereof include polyoxyalkylene glycols (C _2-4 alkylene groups; having a degree of polymerization of 2-50 ) Or a mono-alkyl (C _1-18 ) ether of a polyoxyalkylene polyol [polyoxyalkylene ether of the above-mentioned 3- to 8-valent alcohol (C _2-4 alkyl group; (Meth) acrylate (e.g., methoxypolyethylene glycol (Mw 110-310) (meth) acrylate, or (meth) acrylate (2-30 mol) adduct of lauryl alcohol ethylene oxide).

(J): Examples thereof include monocarboxylic groups such as unsaturated monocarboxylic acid [(meth) acrylic acid, [alpha] -methyl (meth) acrylic acid , Crotonic acid, cinnamic acid, etc.) and monoalkyl (C _1-8 ) esters of unsaturated dicarboxylic acids (maleic acid monoalkyl ether, fumaric acid monoalkyl ester, itaconic acid monoalkyl ester, etc.); And vinyl monomers containing two or more carboxyl groups such as maleic acid, fumaric acid, itaconic acid and citraconic acid.

The monomer (c) is preferred among the above-described additional monomers (c), (d), (e), (f), (g), (h), (i) Two or more of these may be used in combination. Among the monomers (c), monomer (c2) is preferable, and dimethylaminoethyl (meth) acrylate and diethylaminoethyl (meth) acrylate are more preferable.

The hydroxyl value (hydroxyl group value) of the poly (meth) acrylate containing a hydroxyl group used as an additive is in the range of 10 to 100, preferably 20 to 50, more preferably 25 to 35. The hydroxyl value is a numerical value obtained by measurement based on JIS K3342 (1961), which expresses the amount of hydroxyl group in the additive.

When such hydroxyl-group-containing poly (meth) acrylates are incorporated into the grease, there is no adverse effect on the grease structure, a suitable oil film is ensured on the lubricated sliding surface, and the chemical structure containing the hydroxyl group is effectively And an adsorbing film is formed on the lubricated sliding surface. Accordingly, the use of grease containing such hydroxyl-group-containing poly (meth) acrylate can provide an ideal lubricating property on the sliding surface, inhibit wear on the lubricated parts of automobile parts and industrial parts, This is very effective in achieving stability and reliability in terms of the quality of the mechanical parts and the extension of their service life. The main difference between lubricating oil and grease is that in the case of grease the additive and thickener forming the framework of the grease interact with each other so that the effect can be manifested in the case of lubricating oil and the effect of using grease There may be none at all, or alternatively wear may actually be promoted. Therefore, as in the case of the present invention, stable additive which gives effective lubricity with respect to grease is highly preferred.

The grease composition in the manner of the present invention may also optionally contain additional additives such as antioxidants, corrosion inhibitors, oil-based agents, extreme pressure agents, anti-wear agents, solid lubricants, metal deactivators, polymers, metal-based cleaners, Coloring agents and the like. Examples of antioxidants are 2,6-di-tert-butyl-4-methylphenol, 2,6-di-tert-butyl-p-cresol, p, p'- dioctyldiphenyl- alpha -naphthylamine and phenothiazine. Examples of corrosion inhibitors include oxidized paraffins, carboxylic acid metal salts, sulfonic acid metal salts, carboxylic acid esters, sulfonic acid esters, salicylic acid esters, succinic acid esters, sorbitan esters and various types of amine salts. Examples of oily agents, extreme pressure agents and anti-wadding agents include zinc dialkyldithiophosphate sulfide, zinc diallyl dithiophosphate sulfide, zinc dialkyldithiocarbamate sulfide, zinc diallyldithiocarbamate There may be mentioned sulfide, molybdenum dialkyldithiophosphate sulfide, molybdenum diallyldithiophosphate sulfide, molybdenum dialkyldithiocarbamate sulfide, molybdenum diallyldithiocarbamate sulfide , Organomolybdenum complexes, olefin sulfides, triphenyl phosphates, triphenylphosphorothionates, tricresyl phosphates and other phosphate esters, and sulfurized oils / fats and the like. Examples of solid lubricants include molybdenum disulfide, graphite, boronitrile, melamine cyanurate PTFE (polytetrafluoroethylene), tungsten disulfide, graphite fluoride and calcium phosphate. Examples of the metal deactivator include N, N'-disalicylidene-1,2-diaminopropane, benzotriazole, benzimidazole, benzothiazole and thiadiazole and the like. Examples of the polymer include polybutene, polyisobutene, polyisobutylene, polyisoprene, polymethacrylate and the like. Examples of metal-based cleaners are metal sulfonates, metal salicylates and metal phenates. Examples of non-metal-based cleaners include succinimides and the like. However, these examples are not intended to limit the invention.

Next, a description of the amount of each component used in the grease composition associated with the method of the present invention is provided. Unless otherwise indicated,% represents the mass percentage.

The blending amount of the base oil is preferably 60-95 mass%, more preferably 70-90 mass%, and even more preferably 75-90 mass%, taking 100 mass% of the whole grease composition.

The amount of the incorporated thickener {e.g., the urea compound (e.g., alkyldiurea compound)} is preferably from 1 to 20 mass%, more preferably from 2 to 17 mass% More preferably from 3 to 15% by mass.

The amount of the hydroxyl-group-containing poly (meth) acrylate incorporated is preferably 2-20 mass%, more preferably 4-10 mass%, taking 100 mass% of the whole grease composition.

The amount of the other additive is, for example, 0.03 to 20 mass% with respect to the total amount of the arbitrary component, taken as 100 mass% of the whole grease composition.

Particularly preferable compounding examples (particularly regarding the PMA containing a thickening agent and a hydroxyl group), when the type of the thickener is from the above (2-1) to (2-3), the PMA containing such a hydroxyl group (More preferably 10 to 15 mass%) in the case where the type of the hydroxyl group-containing (meth) acrylate is a hydroxyl value = 20-50 and a weight average molecular weight = 1.0 x 10 4 to 2.0 x 10 4) PMA content = 7.5-15 wt%.

The grease composition of the present invention can be produced by a generally used grease production method, and although not particularly limited, as an example of a process for producing a urea grease composition, a 1 molar diisocyanate as a starting material for a urea thickener By reacting 2 mol of a diisocyanate and 1 mol of a primary diamine + 2 mol of a primary monoamine as starting materials for the urea thickener, obtained by reaction of 2 mol of primary monoamine or urea thickener, The triurea obtained by reacting the obtained tetraurea grease thickener or urea thickener with 2 mol of a diisocyanate, 1 mol of a primary diamine, 1 mol of a primary monoamine + 1 mol of a mono-alcohol, - monourethanes were synthesized in each case with base oil in a grease manufacturing kettle to produce the greases used . With regard to a more specific preparation process for carrying out the synthesis reaction of a specific thickener in the base oil, the temperature was raised to a temperature of about 180 ° C, after which cooling was carried out and at a temperature of 100-80 ° C the additive {hydroxyl- Containing poly (meth) acrylate derivative) is incorporated, complete mixing is performed, and then the mixture is cooled to room temperature. Thereafter, the homogenized grease composition can be obtained using a kneading machine (e.g., a triple roll mill or the like).

The dropping point of the grease composition in the method of the present invention is preferably 180 占 폚 or higher, more preferably 210 占 폚 or higher, even more preferably 250 占 폚 or higher, particularly 260 占 폚 or higher. It is believed that when the dripping point of the grease composition is 180 DEG C or higher, the loss of viscosity at high temperature, for example, and the possibility of occurrence of lubrication problems such as accompanying leakage or seizing are suppressed. The dropping point represents the temperature at which the breakage of the structure of the thickener occurs in the case of the viscosity of the grease retained when the temperature is raised. The measurement of the dropping point can be carried out in accordance with JIS K22208.

In the consistency test, the consistency of the grease in the manner of the present invention is in the range of grade 000 to grade 6 (85-475), more preferably grade 0 to grade 4 (175-385), and even more preferably grade 1 To Grade 3 (220-340). Consistency represents the physical hardness of Greece. In the measurement of the consistency, the measurement of the worked penetration can be carried out according to JIS 2220 7.

The friction test was carried out on a high speed 4 ball wear test in ASTM D2596 using a steel ball bearing under conditions including a rotational speed of 12000 rpm for 30 minutes, a load of 40 kgf and ambient temperature (without temperature control) The evaluation is then carried out from the worn-wound diameter in the stopped ball.

The grease composition according to the present invention not only can be used in commonly used machines, bearings and gears, but can also exhibit excellent properties under more severe conditions, such as high temperature conditions. For example, in the case of an automobile it may be a starter, an alternator, various types of actuator devices and other engine peripherals, drive shafts, CVJs, wheel bearings, clutches, and other Can be preferably used in lubrication of electric power steering (EPS), braking devices, ball joints, door hinges, handles, cooling fan motors, brake expanders and various other types of components. In addition, it can also be used in a variety of applications including power shovels, bulldozers, cranes and other types of construction machinery, and railway and paper industries, or forestry equipment, agricultural machinery, chemical equipment, wind turbines, power generators, dry ovens, , And screw joints of seamless five, especially suitable for high temperature / high load applications. Other proposed applications include hard disk bearings, plastic lubrication, cartridge grease and the like, and satisfactory adaptation to the application is also possible.

Example

Next, the present invention will be described in more detail by working examples and comparative examples, but the present invention is not limited in any way by the embodiments provided.

The starting materials used in working examples and comparative examples were as follows.

Starting materials for thickeners

With respect to thickeners A and B, a diurea component having the following chemical structure was used as the thickener.

Thickener A: Urea type I

(a) R ₁ NHCONHR ₂ NHCONHR ₁

Thickener B: Urea type II

(a) R ₁ NHCONHR ₂ NHCONHR ₁

(b) R ₃ NHCONHR ₂ NHCONHR ₃

(C) R ₁ NHCONHR ₂ NHCONHR ₃

Thickener C: Urea type III

(a) R ₄ NHCONHR ₂ NHCONHR ₄

Wherein R ₂ is a diphenylmethane group, R ₁ is an 8-carbon octyl group, R ₃ is a 12-carbon lauryl group, and R ₄ is a 6-carbon phenyl group.

Thickener D: This was a commercial lithium 12-hydroxystearate for industrial use.

Base oils A to C

Base oil A: This is a paraffinic mineral oil obtained by dewaxing / solvent refining, belonging to group I; Its kinematic viscosity is 14.28 mm ² / s at 100 ° C and 144.9 mm ² / s at 40 ° C; Its viscosity index is 96.

Base oil B: This is a poly-a-olefin (PAO) synthetic oil belonging to the IV group, which contains a mixture of low viscosity PAO and high viscosity PAO and controls the kinematic viscosity at 100 DEG C to 15.4 mm ² / s. At 40 ° C the kinematic viscosity of the PAO mixture is 118.9 mm ² / s and its viscosity index is 136.

Base oil C: This is an oil obtained by a GTL (gas liquefaction) process, synthesized by the Fischer-Tropsch process, belonging to group III; Its kinematic viscosity is 8.2 mm ² / s at 100 ° C and 47.9 mm ² / s at 40 ° C; Its viscosity index is 144.

additive

Additive A: Hydroxy-group-containing PMA

(Commercial name: Aclube A-1070, available from Sanyo Chemical Industries Ltd; Mw = 1.7 * 10 ⁴ , hydroxyl value 30)

Additive B: PMA without a hydroxyl group (Aclube V-815, commercially available from Sanyo Chemical Industries Ltd., Mw - 2.1 x 10 ⁴ )

Additive C: PMA (trade name: Aclube 812, manufactured by Sanyo Chemical Industries Ltd., Mw = 3.3 x 10 ⁴ ) without hydroxyl group

Additive D: PMA without a hydroxyl group (commercial name: Aclube C728, manufactured by Sanyo Chemical Industries Ltd., Mw = 4.5 x 10 ⁴ )

Additive E: Ethylene-? -Olefin copolymer (trade name: Lucant HC1OO, manufactured by Mitsui Chemicals Inc.)

Additive F: Polybutene (trade name: Nisseki Polybutene HV-100, manufactured by JX Nippon Oil & Energy Corp.)

Task 1

The starting material, base oil and additives were prepared and weighed in the proportions shown in Table 1 and the grease according to working example 1 was obtained by the usual production method of urea grease. The molar ratio of diisocyanate and primary amine constituting the starting material for the diurea grease thickener used herein was 1: 2. For the detailed preparation method, 60% by weight of the already prepared Group I base oil, i.e. the base oil A, was introduced into a sealed grease test-making kettle and immediately thereafter the diphenylmethane-4,4 ' -Diisocyanate starting material was added while stirring, and the temperature was raised to 50 占 폚. Next, octylamine and laurylamine were each dissolved in the remaining 40 wt.% Group I base oil and finally introduced into the test-making kettle to yield the reaction and formation of the diurea type II thickener. Heating was then continued and the temperature was raised to about 180 DEG C to yield stabilization of the thickener structure. Thereafter, cooling is started and additive A, i.e., a hydroxyl-group-containing poly (meth) acrylate derivative, is added at a temperature of 80 ° C during the cooling treatment, and after complete stirring and mixing, Respectively. Then, the homogeneous grease of Working Example 1 was obtained using a triple roll mill.

Work Example 2

The starting material, base oil and additives were prepared and weighed in the proportions shown in Table 1 and the grease according to working example 2 was obtained by the conventional method of producing urea grease. The molar ratio of diisocyanate and primary amine constituting the starting material for the diurea grease thickener used herein was a ratio of 1: 2. With respect to the detailed preparation method, 60% by weight of the total amount of the synthetic oil already prepared, that is, the base oil B, was introduced into a sealed grease test-production kettle, and then the diphenylmethane-4,4'-di The isocyanate starting material was added while stirring and the temperature was raised to 50 < 0 > C. Next, octylamine was dissolved in the remaining 40 wt.% Synthetic oil and introduced into the test-making kettle to yield the reaction and formation of the diurea type I thickener. Heating was then continued and the temperature was raised to about 180 DEG C to yield stabilization of the thickener structure. Thereafter, cooling is started and additive A, i.e., a hydroxyl-group-containing poly (meth) acrylate derivative, is added at a temperature of 80 ° C during the cooling treatment, and after complete stirring and mixing, Respectively. Then, the homogeneous grease of Working Example 2 was obtained using a triple roll mill.

Work Example 3

The starting material, base oil and additives were prepared and weighed in the proportions shown in Table 1 and the grease according to working example 3 was obtained by the usual preparation method of urea grease. The molar ratio of diisocyanate and primary amine constituting the starting material for the diurea grease thickener used herein was 1: 2. For the detailed preparation method, 60% by weight of the already prepared Group III base oil, i.e. Base Oil C, is introduced into the sealed grease test-making kettle and immediately thereafter the diphenylmethane-4,4 ' -Diisocyanate starting material was added while stirring, and the temperature was raised to 50 占 폚. Next, octylamine was dissolved in the remaining 40 wt% Group III base oil and introduced into the test-making kettle to yield the reaction and formation of the diurea type I thickener. Heating was then continued and the temperature was raised to about 180 DEG C to yield stabilization of the thickener structure. Thereafter, cooling is started and additive A, i.e., a hydroxyl-group-containing poly (meth) acrylate derivative, is added at a temperature of 80 ° C during the cooling treatment, and after complete stirring and mixing, Respectively. Thereafter, the homogeneous grease of Working Example 3 was obtained using a triple roll mill.

Task Example 4-6

Starting materials, base oils and additives were prepared and weighed in the ratios shown in Table 1 and the greases according to working examples 4 to 6 respectively were obtained by the usual production method of urea grease. The molar ratio of diisocyanate and primary amine constituting the starting material for each diurea grease thickener used herein was 1: 2. For the detailed preparation method, 60% by weight of the already prepared Group I base oil, i.e. the base oil A, was introduced into a sealed grease test-making kettle and immediately thereafter the diphenylmethane-4,4 ' -Diisocyanate starting material was added while stirring, and the temperature was raised to 50 占 폚. Next, octylamine and laurylamine were each dissolved in the remaining 40 wt.% Group I base oil and finally introduced into the test-making kettle to yield the reaction and formation of the diurea type II thickener. Heating was then continued and the temperature was raised to about 180 DEG C to yield stabilization of the thickener structure. Thereafter, cooling is started and additive A, i.e., a hydroxyl-group-containing poly (meth) acrylate derivative, is added at a temperature of 80 ° C during the cooling treatment, and after complete stirring and mixing, Respectively. Each of the homogeneous greases of Working Examples 4 to 6 was then obtained using a triple roll mill. In working examples 4 to 6, the amount of base oil was balanced according to the difference in the amount of the used additive, and again the amount of thickening agent was also slightly adjusted.

Operation Example 7

The starting material, base oil and additives were prepared and weighed in the proportions shown in Table 1 and the grease according to working example 7 was obtained by the usual preparation method of urea grease. The molar ratio of diisocyanate and primary amine constituting the starting material for the diurea grease thickener used herein was 1: 2. With respect to the detailed preparation method, 60% by weight of the total amount of the already prepared Group I base oil, base oil A, was introduced into a sealed grease test-production kettle, and immediately thereafter the diphenylmethane-4,4'- The diisocyanate starting material was added while stirring and the temperature was raised to 50 < 0 > C. Next, octylamine was dissolved in the remaining 40 wt.% Group I base oil and introduced into the test-making kettle to yield the reaction and formation of the diurea type I thickener. Heating was then continued and the temperature was raised to about 180 DEG C to yield stabilization of the thickener structure. Thereafter, cooling is started and additive A, i.e., a hydroxyl-group-containing poly (meth) acrylate derivative, is added at a temperature of 80 ° C during the cooling treatment, and after complete stirring and mixing, Respectively. Thereafter, the homogeneous grease of Working Example 7 was obtained using a triple roll mill.

Operation Example 8

The starting material, base oil and additives were prepared and weighed in the proportions shown in Table 1, and the grease according to Working Example 8 was obtained by the usual production method of urea grease. The molar ratio of diisocyanate and primary amine constituting the starting material for the diurea grease thickener used herein was 1: 2. For the detailed preparation method, a total amount of already prepared Group I base oil, i.e. base oil A, was introduced into a sealed grease test-making kettle, followed immediately by diphenylmethane-4,4'-diisocyanate for urea thickener The material was stirred while adding and the temperature was raised to 50 < 0 > C. Next, octylamine is mixed with a synthetic oil, i.e., base oil B, laurylamine is mixed and dissolved in base oil C belonging to group III, which is finally introduced into a test-making kettle, The formation of type II thickener was calculated. Heating was then continued and the temperature was raised to about 180 DEG C to yield stabilization of the thickener structure. Thereafter, cooling is started and additive A, i.e., a hydroxyl-group-containing poly (meth) acrylate derivative, is added at a temperature of 80 ° C during the cooling treatment, and after complete stirring and mixing, Respectively. Thereafter, the homogeneous grease of Working Example 8 was obtained using a triple roll mill.

Action Example 9

The starting material, base oil and additives were prepared and weighed in the proportions shown in Table 1 and the grease according to working example 9 was obtained by the usual production method of urea grease. The molar ratio of diisocyanate and primary amine constituting the starting material for the diurea grease thickener used herein was 1: 2. For the detailed preparation method, 60% by weight of the already prepared Group I base oil, i.e. the base oil A, was introduced into a sealed grease test-making kettle and immediately thereafter the diphenylmethane-4,4 ' -Diisocyanate starting material was added while stirring, and the temperature was raised to 50 占 폚. The aniline was then mixed and dissolved in the remaining 40 wt% Group I base oil and introduced into the test-making kettle to yield the reaction and formation of the diurea type III thickener. Heating was then continued and the temperature was raised to about 180 DEG C to yield stabilization of the thickener structure. Thereafter, cooling is started and additive A, i.e., a hydroxyl-group-containing poly (meth) acrylate derivative, is added at a temperature of 80 ° C during the cooling treatment, and after complete stirring and mixing, Respectively. Then, the homogeneous grease of Working Example 9 was obtained using a triple roll mill.

Task Example 10

Hydroxystearate and Group I base oil, i.e. base oil A, for industrial use, in the proportions shown in Table 1, and the total amount of this base oil and lithium 12-hydroxystearate was measured in a sealed A grease test-production kettle was introduced and stirred while raising the temperature to 230 ° C. After confirming that the lithium 12-hydroxystearate was completely dissolved, the temperature was gradually decreased to 80 占 폚. Additive A, i.e. a hydroxyl-group-containing poly (meth) acrylate derivative, was then added at such a temperature of 80 캜, and after complete stirring and mixing, cooling to room temperature was continued. Thereafter, the homogeneous grease of Working Example 10 was obtained using a triple roll mill.

Comparative Examples 1 to 3

Using the manufacturing method described in Working Example 6, a thickener formation reaction was performed and comparative greases were obtained, respectively, wherein Comparative Example 1 was a base grease without additive. In Comparative Example 2, additive B was introduced. In Comparative Example 3, additive C was introduced.

Comparative Examples 4 to 6

Using the manufacturing process described in Working Example 1, a thickener formation reaction was carried out and comparative greases were obtained, in which additive D was incorporated into Comparative Example 4. In Comparative Example 5, additive E was incorporated. In Comparative Example 6, additive F was incorporated.

The results obtained are shown in Table 1. Using greases in accordance with working examples 1 to 10, it was seen from table 1 that excellent abrasion resistance was obtained in each case (wear-scratch diameter 0.39-0.52).

[Table 1]

* Mixture illumination: 60 W at 25 ° C (measured in 1/2 illuminance / consistency meter)

** High speed 4 ball wear test: l, 200rpm, 40kgf, ambient temperature (no temperature control), 30min

Claims (10)

Base oil, thickener, and poly (meth) acrylate containing hydroxyl groups. The grease composition of claim 1, wherein the thickener is a urea compound formed by reaction between an isocyanate and a primary amine. 3. The method of claim 2, wherein the urea compound is a diurea compound obtained by the reaction between a diisocyanate and a primary monoamine; A tetraurea compound obtained by a reaction between a diisocyanate, a primary diamine and a primary monoamine; Or a triurea-monourethane compound obtained by reaction between a diisocyanate, a primary diamine, a primary monoamine and a monoalcohol. The grease composition according to claim 2, wherein the urea compound is a compound represented by the following formula (I):
R ¹ -NHCONH-R ² -NHCONH-R ³ (I)
_Wherein R ¹ and R ³ are each a C _8-12 aliphatic hydrocarbon group and R ² is a C _6-152 aromatic group. The poly (meth) acrylate according to any one of claims 1 to 4, wherein the poly (meth) acrylate containing a hydroxyl group comprises an alkyl (meth) acrylate having a C _1-20 alkyl group and a hydroxyl- A grease composition comprising a copolymer as a monomer. The grease composition according to claim 5, wherein the alkyl (meth) acrylate having a C _1-20 alkyl group is an alkyl (meth) acrylate having a C _8-20 alkyl group. 7. The composition of claim 5 or 6 wherein the hydroxyl-containing vinyl monomer is selected from the group consisting of hydroxyalkyl (C _2-6 ) (meth) acrylate, mono- or di-hydroxyalkyl (C _1-4 ) (Meth) acrylamide, vinyl alcohol (formed by hydrolysis of the vinyl acetate unit), C _3-12 alkenol, C _4-12 alkenediol, hydroxyalkyl (C _1-6 ) alkenyl (C _3-10 ) Ether, a hydroxyl-group-containing aromatic monomer, a polyhydric alcohol, and a vinyl monomer containing a polyoxyalkylene chain and a hydroxyl group (s). The positive photosensitive composition as claimed in any one of claims 5 to 7, wherein the copolymer is selected from the group consisting of nitro-group-containing monomers, vinyl monomers containing primary, secondary or tertiary amino groups, amphoteric vinyl monomers and monomers containing nitrile groups A grease composition having additional constituent monomers selected. 9. The grease composition according to any one of claims 1 to 8, wherein the hydroxyl value of the hydroxyl group-containing poly (meth) acrylate is 20 to 50. 10. The lubricating oil composition according to any one of claims 1 to 9, wherein the total grease composition is taken as 100% by mass, 60 to 95% by mass of base oil, 1 to 20% by mass of thickener and 2 to 20% (Meth) acrylate.