CN104011190A - grease composition - Google Patents

Abstract

Grease composition with high wear resistance, comprising base oil, thickener and poly(meth)acrylate derivative.

Description

grease composition

technical field

The present invention relates to grease compositions and more particularly to grease compositions having high wear resistance.

Background of the invention

Sliding parts and rotating parts of machinery require some type of lubricating base, so that oil or grease is used in large quantities, and especially many machines use a grease lubrication system that can simplify the sealing structure and make the equipment small and compact. The range of use is very wide, covering such as various types of ball-roller bearings and plain bearings supporting rotating bodies, as well as sliding parts and connections of ball joints or chains, gears, wires and crane jibs, etc., and their Quality requirements are increasing year by year, while the extension of machine life and maintenance-free operation are common problems for all machinery. In addition, as mechanical technology, material technology, and machining accuracy have progressed in recent years, fatigue failures and material damage have become rare, so machine life has become greatly affected by the effectiveness of lubricating oil or grease. Thus, enhancing the lubricating properties of grease and solving problems related thereto can greatly contribute to the improvement of mechanical quality and reliability, and are therefore very important.

In particular, the case where the lubricating efficiency of the grease in the rotating components or sliding parts of the machine decreases and the life of the machine is exhausted can be broadly classified into two. The first is the case in which the grease is oxidized when used at high temperature, so there is grease solidification caused by evaporation of oil components or thermal polymerization, or grease structure decomposes with subsequent formation of organic acids or aldehydes, causing lubrication failure. The second is the case where during use under high load at relatively low speed or during use at high speed, as a result of significant sliding friction at mechanical sliding surfaces, a boundary lubrication state tends to occur and the lubricating film of grease becomes extremely Thin, so frequent metal/metal contact occurs and increases wear, leading to damage such as metal separation or seizure.

Means to overcome the situation described in the first case above include methods aimed at extending machine life by effectively incorporating suitable antioxidants into greases (see Japanese Patent No. 2085136), or using as a grease component almost no heat-induced Structurally or chemically alter the thickener or base oil, thereby enhancing the overall function of the grease to extend machine life. An example of a urea-based grease heat-stable thickener and there have been many technical developments recently with the use of this thickener (see Japanese Patent 4769456). Urea greases are used in a wide range of fields because they have a higher dropping point than greases using lithium soap as a thickener, and because they are excellent in thermal stability and wear resistance and lubricity. For example, in the automotive industry, the required levels of heat resistance, wear resistance and friction characteristics associated with various types of motor vehicle components such as CVJs (Constant Velocity Joints), electrical controls, alternator bearings and steel bearings, etc. have been steadily increasing, so there are many cases where the superior performance and addition techniques of urea greases are applied.

In addition, since motor vehicles are used all over the world, the design and production of greases used in motor vehicle components need to take into account the extreme cold of about -40°C and the high temperature of 100°C and above (radiant heat from the engine room + heat generation from the road surface) Regular use under conditions, and low stabilized torque characteristics obtained over a wide temperature range from low to high temperatures, requires greases that do not show lack of lubrication due to viscosity reduction at high temperatures and that also have inherent compatibility with the medium Long life to match.

In order to enhance low temperature characteristics, a technique has been disclosed in which methacrylate polymers are incorporated into synthetic hydrocarbon oils (poly-α-olefins), ester base oils, or glycol bases with excellent low temperature fluidity oil as a grease base oil, but further improvements in quality and performance are still required (see JP-A-2006-77119).

Means for overcoming the second situation described above include methods in which the grease base oil viscosity is increased and polymers or other viscosity enhancers are incorporated so that the lubricating film thickens and metal/metal contact is inhibited (see JP-A-2008-69282); and a method in which an antiwear agent, an extreme pressure agent, a solid lubricant, or other load-resistant additives are incorporated into grease so that by the chemical or physical action of the additive, the A coating or a solid film is formed with the surface thus protected (see Japanese Patent No. 3833756 and JP-A-2-18497). However, depending on the type of additive, the grease structure can be changed, and there are also many additives that have adverse effects on mechanical components. For example, high acid value thiophosphates have the disadvantage of reacting easily with the free base of soap-based greases, while olefin sulfide-based additives can cause urea greases to cure over time. In addition, in the case of additives having strong chemical activity, there are many problems such as discoloration or corrosion of metals and reduction in strength of sealing substances such as nitrile, acrylic or urethane rubber.

Therefore, in terms of grease lubrication, it is possible to maintain a suitable oil film on the lubricated sliding surface and form an adsorbed film without any adverse effects on the structure of the grease, which is important in stabilizing the quality of motor vehicle parts and industrial components and ensuring reliability. It is extremely effective in terms of sex and prolonging the life of the actual machine.

Summary of the invention

The problem addressed by the present invention is to provide a grease composition with high wear resistance. As a result of painstaking research in this context, the inventors have found that it is possible to improve the wear resistance of greases by using poly(meth)acrylate derivatives containing hydroxyl groups, and in this way it is possible to solve the aforementioned problems.

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

The grease composition according to the present invention exhibits a higher wear resistance effect than conventional grease compositions.

Detailed description of the invention

The grease composition of this embodiment contains "base oil", "thickener" and "additives" as essential constituent components. Explained in order below are the individual components contained in the grease composition, the amounts of the components in the grease composition (blend amounts), the method of producing the grease composition, the characteristics of the grease composition, and grease composition applications.

The base oil used in the grease composition of this mode of the present invention is not particularly limited. For example, mineral oils, synthetic oils, animal/vegetable oils and mixtures thereof used in conventional grease compositions can be suitably used. As specific examples, base oils belonging to API (American Petroleum Institute) base oil categories Group I, Group II, Group III, Group IV, etc. can be used alone or in admixture.

Group I base oils include alkane mineral oils obtained, for example, with suitable combinations of purification means such as solvent refining, hydro-refining and dewaxing, up to lubricating oil fractions obtained by atmospheric distillation of crude oil. Group II base oils include alkane mineral oils obtained, for example, with a suitable combination of purification means such as hydrocracking and dewaxing, up to lubricating oil fractions obtained by atmospheric distillation of crude oil. Group II base oils produced by hydro-refining processes such as the Gulf Co. process have a total sulfur component content of less than 10 ppm and an aromatics content of no more than 5%, and can be advantageously used in the present invention. Group III base oils and Group II+ base oils include, for example, paraffinic mineral oils produced by high-level hydro-refining of lube oil fractions obtained by atmospheric distillation of crude oil, and by converting therein the waxes formed during dewaxing Base oils refined by the isomerization dewaxing process of isoparaffins, as well as base oils produced by the Mobil wax isomerization process, can likewise be advantageously used in this mode of the invention.

Examples of synthetic oils include polyolefins, diesters of dicarboxylic acids such as dioctyl sebacate, polyol esters, alkylbenzenes, alkylnaphthalenes, esters, polyoxyalkylene glycols, polyoxyalkylene glycol esters , polyoxyalkylene glycol ether, polyphenyl ether, dialkyl diphenyl ether, fluorine-containing compounds (perfluoropolyether, fluorinated polyolefin, etc.), and silicone, etc. The aforementioned polyolefins include various types of olefin polymers and hydrogenated products thereof. Any olefin may be used and examples are ethylene, propylene, butene, and α-olefins having 5 or more carbon atoms. In the production of polyolefins, a single type of the aforementioned olefins may be used alone, or a combination of two or more types may be used. In particular, polyolefins called poly-alpha-olefin (PAO) synthetic oils are preferable from the viewpoint of enhancing low-temperature fluidity and low-temperature lubricity, and they are Group IV base oils. Since poly-α-olefin synthetic oils have a high viscosity index, their viscosity hardly decreases at high temperatures and their ability to maintain an oil film is high, and in addition, their viscosity does not increase excessively at low temperatures and maintains suitable fluidity, so lubricity is hardly decline. This excellent low temperature behavior works extremely effectively when used in the base oil of a grease. For example, if a lubricating oil that has an extremely high viscosity at low temperatures and thus loses fluidity is used as a grease base oil, the fluidity of the grease is completely compromised and there is practically no supply of lubricating oil to the sliding surfaces of mechanical components, so wear can be performed; in contrast, if a grease blended with a base oil having excellent low-temperature fluidity such as poly-α-olefin synthetic oil is used, there is no loss of fluidity and the lubricating oil can be properly supplied to the sliding surface, Thereby the lubricating function is maintained and wear is suppressed.

Oils obtained by the GTL (Gas to Liquids) process, which are oils synthesized from natural gas in liquid fuel conversion technology using the Fischer Tropsch method, which have an extremely low sulfur group compared to mineral oil base oils obtained by crude oil refining content of components and aromatic components, and an extremely high proportion of paraffinic structures, as a result of which they have excellent oxidation stability and very low evaporation losses, so they can advantageously be used as base oils in this mode of the invention.

The thickener used as an essential component in this mode of the invention is not particularly limited, and it may be of the type used in ordinary grease compositions. Examples are urea thickeners, metallic soaps, complex soaps, organized bentonites and silicas, etc. Examples of urea-based thickeners are aliphatic diureas, cycloaliphatic diureas, aromatic diureas, triureas, tetraureas and urea-urethanes. Examples of metal soaps are lithium 12-hydroxystearate, lithium stearate, calcium 12-hydroxystearate, calcium stearate, lithium complex, calcium complex, barium complex, aluminum complex, lithium-calcium Mix soap etc. An example of an organized bentonite is montmorillonite that has been treated with a quaternary ammonium salt, and an example of silica is an ultrafine silica powder produced by a gas phase reaction, or this ultrafine silica powder after surface treatment with a lower alcohol such as methanol. Silicon oxide powder. 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 can be, for example, diurea, triurea, tetraurea, pentaurea or hexurea, and it can be aliphatic urea, cycloaliphatic urea or aromatic urea, and it can also have other groups such as carbamic acid ester groups) (as in the case of urea-urethanes).

Diurea thickeners are obtained, for example, by reacting 1 mol of diisocyanate with 2 mol of primary monoamines. In addition, tetraurea thickeners are obtained, for example, by reacting 2 mol of diisocyanate with 1 mol of primary diamine and 2 mol of primary monoamine. Furthermore, triurea-monourethane thickeners are obtained, for example, by reacting 2 mol of diisocyanate with 1 mol of primary diamine and 1 mol of primary monoamine and 1 mol of monoalcohol. Hereinafter, examples of various raw materials used in synthesizing these urea compounds are provided.

In the case of diisocyanates, there are aliphatic diisocyanates, alicyclic diisocyanates, aromatic diisocyanates, and the like. More specific examples are 4,4'-diphenylmethane diisocyanate (MDI), tolylene diisocyanate (TDI), naphthalene diisocyanate, p-phenylene diisocyanate, trans-1,4-cyclohexane Alkane diisocyanate (CHDI), 1,3-bis-(isocyanatomethyl-benzene), 4,4'-dicyclohexylmethane diisocyanate (H12MDI), 1,3-bis(isocyanatomethyl-benzene) base)-cyclohexane (H6XDI), hexamethylene diisocyanate (HDI), 3-isocyanatomethyl-3,3,5'-trimethyl-cyclohexyl isocyanate (IPDI), phenylene Diisocyanates, m-tetramethylxylene diisocyanate (m-TMXDI), p-tetramethylxylene diisocyanate (p-TMXDI), etc., especially 4,4'-diphenylmethane diisocyanate (MDI) , tolylene diisocyanate (TDI), trans-1,4-cyclohexane diisocyanate (CHDI) and 4,4'-dicyclohexylmethane diisocyanate (H12MDI).

Primary monoamines can be aliphatic, cycloaliphatic or aromatic monoamines. As the aliphatic amine, a C ₈ to C ₂₄ saturated or unsaturated aliphatic amine may be used, which may be a branched chain or a straight chain, but a straight chain aliphatic amine is preferred. Specific examples of primary monoamines include octylamine, decylamine, dodecylamine, tetradecylamine, hexadecylamine, stearylamine, oleylamine, aniline, p-toluidine and cyclic Hexylamine.

Primary diamines can be aliphatic, cycloaliphatic or aromatic diamines. Examples include C2 _{to C12} diamines such as aliphatic diamines such as ethylenediamine, trimethylenediamine, tetramethylenediamine, hexamethylenediamine, octamethylenediamine and decamethylene-diamine , cycloaliphatic diamines such as diaminocyclohexane, and aromatic diamines such as phenylenediamine, benzidine, diaminostilbene and benzidine.

The monoalcohols can be aliphatic, cycloaliphatic or aromatic alcohols. As the aliphatic monoalcohol herein, a _C8 to _C24 saturated or unsaturated aliphatic alcohol may be used, which may be a branched chain or a straight chain, but a straight chain alcohol is preferred. Specific examples include octyl alcohol, decyl alcohol, dodecyl alcohol, myristyl alcohol, cetyl alcohol, stearyl alcohol and oleyl alcohol, while an example of cycloaliphatic alcohol is cyclohexyl alcohol, And examples of aromatic alcohols are benzyl alcohol, salicyl alcohol, phenylethyl alcohol, cinnamyl alcohol, hydrogenated cinnamyl alcohol and the like.

In particular, alkyl diureas are preferred, more preferably compounds of general formula (I):

R ¹ -NHCONH-R ² -NHCONH-R ³ (I)

(where R ¹ and R ³ each represent a C _8-12 aliphatic hydrocarbon group, and R ² represents a C _6-15 divalent aromatic group). Herein, it is preferred that R ¹ and R ³ independently of each other are octa-carbon octyl or dodecyl-lauryl. In addition, ^R2 is preferably a diphenylmethane group. In a more preferred embodiment, compounds are used wherein R ² is a diphenylmethane group and (1) R ¹ and R ³ are octacarbonyl groups, or (2-1) wherein R ¹ and R ³ are each A mixture of a compound of octacarbonyl and a compound wherein R ^and R are dodecyl lauryl, ( ^2-2 ) a compound wherein ^R or ^R is octacarbonyl, and ^R and ^R are The other is dodecyl lauryl, and (2-3) one or both of the compounds in (2-1) and a mixture of the compounds in (2-2). Among these, (2-1) to (2-3) are particularly preferable.

In the grease composition of this mode of the present invention, it is possible to use yet another thickener in common with the main thickener {which is, for example, the aforementioned urea compound (such as an alkyldiurea)}. Thus, in the case of using a urea compound as the main thickener, it is possible to use, as the above-mentioned other thickeners, tribasic calcium phosphate, alkali metal soap, alkali metal complex soap, alkaline earth metal soap, alkaline earth metal complex soap, Alkali metal sulfonates, alkaline earth metal sulfonates, other metal soaps, metal p-aminocarbonylbenzoates, clays, silica aerogels or other types of silica (silicon oxides), or fluoropolymers Such as polytetrafluoroethylene and the like, and one of these can be used alone or two or more can be used in combination. In addition to these, it is also possible to use arbitrary substances capable of bringing about a viscosity-increasing effect.

The additive used as an essential component in this embodiment is poly(meth)acrylate containing hydroxyl groups. The hydroxyl-containing poly(meth)acrylate is a copolymer, and contains, as its essential components, an alkyl (meth)acrylate having a C _1-20 alkyl group and a hydroxyl-containing vinyl monomer monomeric copolymers.

Specific examples of the aforementioned alkyl (meth)acrylate (a) having a C _1-20 alkyl group are

(a1) Alkyl (meth)acrylates with C _1-4 alkyl groups:

Examples are methyl (meth)acrylate, ethyl (meth)acrylate, n- or isopropyl (meth)acrylate, and n-, iso-, or sec-butyl (meth)acrylate base ester,

(a2) Alkyl (meth)acrylate with C _8-20 alkyl:

Examples thereof are n-octyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, n-decyl (meth)acrylate, n-isodecyl (meth)acrylate, ( n-undecyl methacrylate, n-dodecyl (meth)acrylate, 2-methylundecyl (meth)acrylate, n-tridecyl (meth)acrylate Base ester, 2-methyldodecyl (meth)acrylate, n-tetradecyl (meth)acrylate, 2-methyltridecyl (meth)acrylate, (meth) n-pentadecyl acrylate, 2-methyltetradecyl (meth)acrylate, n-hexadecyl (meth)acrylate, n-octadecyl (meth)acrylate, n-eicosyl (meth)acrylate, n-eicosyl (meth)acrylate, Dovanol23 [C ₁₂ /C ₁₃ oxo-alcohol mixture produced by Mitsubishi Chemical Corp.] methacrylate and Dovanol 45 [C ₁₃ /C ₁₄ oxo-alcohol mixture produced by Mitsubishi Chemical Corp.] methacrylate, etc.,

(a3) Alkyl (meth)acrylates with C _5-7 alkyl groups:

Examples thereof are n-pentyl (meth)acrylate, n-hexyl (meth)acrylate, and the like.

Among the above (a1) to (a3), monomers belonging to (a1) and (a2) are preferable, and those belonging to (a2) are more preferable. Furthermore, among the monomers of (a2), those having 10 to 20 carbons in the alkyl group are preferable and those having 12 to 14 carbons are more preferable in terms of solubility in base oil.

The aforesaid hydroxyl-containing vinyl monomer (b) constituting the copolymer together with an alkyl (meth)acrylate having a C1-20 alkyl group is vinyl containing one or more (preferably 1 or 2) hydroxyl groups in the molecule. base monomer. specific instance is

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

Such as 2-hydroxyethyl (meth)acrylate, 2- or 3-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 1-methyl-(meth)acrylate 2-hydroxyethyl ester, etc.,

(b2) Mono- or di-hydroxyalkyl (C _1-4 )-substituted (meth)acrylamides:

Such as N,N-dihydroxymethyl (meth)acrylamide, N,N-dihydroxypropyl (meth)acrylamide, N,N-di-2-hydroxybutyl (meth)acrylamide, etc.,

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

(b4) C _3-12 enols:

Such as (meth)allyl alcohol, crotyl alcohol, isocrotyl alcohol, 1-octenol, 1-undecenyl alcohol, etc.

(b5) C _4-12 olefinic diols:

Such as 1-butene-3-ol, 2-butene-1-ol, 2-butene-1,4-diol, etc.

(b6) Hydroxyalkyl (C _1-6 ) alkenyl (C _3-10 ) ethers:

Such as 2-hydroxyethyl propenyl ether, etc.,

(b7) Hydroxyl-containing aromatic monomers:

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

(b8) Polyhydric alcohols (tri- to octa-hydroxy):

Such as alkane polyols, and their intramolecular or intermolecular dehydrogenated condensates, and sugars (such as glycerol, pentaerythritol, sorbitol, sorbitan, diglycerol or sucrose) alkenyl (C3-10) ethers or ( Meth)acrylics (e.g. sucrose (meth)allyl ether), etc.,

(b9) Vinyl monomers containing polyoxyalkylene chains and hydroxyl groups:

Such as polyoxyalkylene diol (C _2-4 alkylene; polymerization degree 2 to 50) or polyoxyalkylene polyol {polyoxyalkylene ether (C _2-4 alkyl; Mono(meth)acrylate or mono(meth)allyl ether {example is polyethylene glycol (polymerization degree 2-9) mono(meth)acrylate/ Ester, polypropylene glycol (polymerization degree 2-12)-(meth)acrylate/ester, polyethylene glycol (polymerization degree 2-30)-(meth)allyl ether}, etc.

It is also possible to copolymerize other monomers with the aforementioned monomers (a) and (b) in the aforementioned hydroxyl group-containing poly(meth)acrylate copolymer, and for example, a nitrogen atom-containing monomer (c) may be used. A specific instance of which is

(c1) Nitro-containing monomers: such as 4-nitrostyrene, etc.,

(c2) Vinyl monomers containing primary, secondary or tertiary amino groups: examples of which are

(c2-1) Vinyl monomers containing primary amino groups; such as C _3-6 alkenylamine [(meth)allylamine, crotylamine, etc.], (meth)acrylic acid aminoalkyl (C _{2- 6} ) Esters [(meth)aminoethyl acrylate, etc.],

(c2-2) Vinyl monomers containing secondary amino groups; such as alkyl (C _1-6 ) aminoalkyl (C _2-6 ) (meth)acrylate [tert-butylaminoethyl methacrylate, Methylaminoethyl (meth)acrylate, etc.], diphenylamine (meth)acrylamide [4-diphenylamine (meth)acrylamide, 2-diphenylamine (meth)acrylamide, etc.], C _{6- 12} Dienylamine [di(meth)allylamine, etc.],

(c2-3) Vinyl monomers containing tertiary amino groups; such as dialkyl (C _1-4 )-aminoalkyl (C _2-6 ) (meth)acrylate [(meth)acrylate dimethylamino ethyl ester, diethylaminoethyl (meth)acrylate, etc.], dialkyl (C _1-4 ) aminoalkyl (C _2-6 ) (meth)acrylamide [dimethylaminoethyl -(meth)acrylamide, diethylaminoethyl(meth)acrylamide, dimethylaminopropyl-(meth)acrylamide, etc.], aromatic vinyl monomers containing tertiary amino groups [N, N-dimethylaminostyrene, etc.],

(c2-4) Vinyl monomers containing nitrogen heterocycles [morpholinoethyl (meth)acrylate, 4-vinylpyridine, 2-vinylpyridine, N-vinylpyrrole, N-vinylpyrrolidone , N-vinylthiopyrrolidone, etc.],

(c3) Amphoteric vinyl monomers: Examples thereof are

N-(meth)acryloyloxy (or amino) alkyl (C _1-10 ) N,N-dialkyl (C _1-5 ) ammonium-N-alkyl (C _1-5 ) carboxylates / Esters (or sulfates / esters), such as N-(meth)acryloyloxyethyl N,N-dimethylammonium N-methyl carboxylate / esters, N-(meth)acryloylamino Propyl N,N-dimethylammonium N-methyl carboxylate and N-(meth)acryloyloxyethyl N,N-dimethylammonium propyl sulfate, etc.; and

(c4) Monomers containing nitrile groups, such as (meth)acrylonitrile and the like.

Furthermore, other examples of the comonomers are aliphatic hydrocarbon-type vinyl monomers (d). Examples of these are _C2-20 alkenes [ethylene, propylene, butene, isobutylene, pentene, heptene, diisobutylene, octene, dodecene, octadecene, etc.] and _{C4 -12} dienes [butadiene, isoprene, 1,4-pentadiene, 1,6-heptadiene, 1,7-octadiene, etc.].

Again, there are cycloaliphatic hydrocarbon-type vinyl monomers (e): examples of which are cyclohexene, (di)cyclopentadiene, pinene, limonene, indene, vinylcyclohexene and ethylenebicyclo Heptene etc.

Additionally, aromatic-type vinyl monomers (f) are present: examples of which are styrene, α-methylstyrene, vinyltoluene, 2,4-dimethylstyrene, 4-ethylstyrene, 4 - Isopropylstyrene, 4-butylstyrene, 4-phenylstyrene, 4-cyclohexylstyrene, 4-benzylstyrene, 4-crotonylbenzene and 2-vinylnaphthalene, etc.

Also again, there are vinyl esters, vinyl ethers and vinyl ketones (g): examples of which are vinyl esters of saturated _C2-12 fatty acids [vinyl acetate, vinyl propionate, vinyl butyrate, vinyl octanoate esters, etc.], C _1-12 alkyl, aryl or alkoxyalkyl vinyl ethers [methyl vinyl ether, ethyl vinyl ether, propyl vinyl ether, butyl vinyl ether, 2-ethyl vinyl ether, ylhexyl vinyl ether, phenyl vinyl ether, vinyl 2-methoxyethyl ether, vinyl 2-butoxyethyl ether, etc.] and C _1-8 alkyl or aryl vinyl ketones [ vinyl ketone, ethyl vinyl ketone, phenyl vinyl ketone, etc.].

Furthermore, there are esters (h) of unsaturated polycarboxylic acids: examples thereof are alkyl, cycloalkyl and aralkyl esters of unsaturated polycarboxylic acids, especially unsaturated dicarboxylic acids [e.g. maleic acid, fumaric acid, acid and itaconic acid] C _1-8 alkyl diester [such as dimethyl maleate, dimethyl fumarate, diethyl maleate and dioctyl maleate, etc.].

It is also possible to use vinyl monomers (i) containing polyoxyalkylene chains (but no hydroxyl groups): examples of these are polyoxyalkylene diols (C _2-4 alkylene; degree of polymerization 2-50) or poly Mono-(methyl) of mono-alkyl (C _1-18 ) ethers of oxyalkylene polyols [polyoxyalkylene ethers (C _2-4 alkyl; degree of polymerization 2-100) of the aforementioned trihydric to octahydric alcohols] Base) acrylate, [such as methoxypolyethylene glycol (Mw110-310) (meth)acrylate, or (meth)acrylate of lauryl alcohol ethylene oxide (2-30mol) adduct, etc. ]

Again, as a monomer in the aforementioned copolymerization, it is also possible to use a carboxyl group-containing vinyl monomer (j): examples thereof are vinyl monomers containing a single carboxyl group such as unsaturated monocarboxylic acid [(meth)acrylic acid, α - methyl (meth)acrylic acid, crotonic acid, cinnamic acid, etc.] and monoalkyl (C _1-8 ) esters of unsaturated dicarboxylic acids [monoalkyl maleate, monoalkyl fumarate , monoalkyl itaconate, etc.]; and vinyl monomers containing two or more carboxyl groups such as maleic acid, fumaric acid, itaconic acid and citraconic acid, etc.

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

The hydroxyl value (hydroxyl number) of the hydroxyl group-containing poly(meth)acrylate used as an additive is 10 to 100, preferably 20 to 50, and more preferably 25 to 35. The hydroxyl value is a value obtained by measurement based on JIS K3342 (1961), and it indicates the amount of hydroxyl groups in the additive.

In the case where the hydroxyl-containing poly(meth)acrylate is incorporated into the grease, there is no adverse effect on the grease structure, a suitable oil film is fixed on the lubricated sliding surface, and in addition, the hydroxyl-containing chemical The structure functions effectively and forms an adsorbed film on lubricated sliding surfaces. Thus, in the case of incorporating such a hydroxyl group-containing poly(meth)acrylate grease, it is possible to provide ideal lubricity at sliding surfaces and suppress wear of lubricated parts of motor vehicle components and industrial components, and It is extremely effective in achieving stability and reliability in the quality of mechanical parts and prolonging their life. The main difference between oils and greases is that, in the case of greases, the thickener and additives that form the structural framework of the grease interact together, so while the effect can be manifested in the case of oils, it can be seen in the case of greases It may have no effect, or alternatively may actually promote wear. Thus, additives to greases that are stable and confer effective lubricity are highly advantageous, as is the case in the present technology.

The grease composition of this mode of the invention may also optionally contain further additives such as antioxidants, rust inhibitors, oily agents, extreme pressure agents, anti-wear agents, solid lubricants, metal deactivators, polymers, metal base cleaners, non-metal based cleaners, colorants, etc. Examples of antioxidants include 2,6-di-tert-butyl-4-methylphenol, 2,6-di-tert-butyl-p-cresol, p,p'-dioctyldiphenyl-amine, N-phenyl-α-naphthylamine and phenothiazine. Examples of rust inhibitors include oxidized paraffin, carboxylate metal salts, sulfonate metal salts, carboxylate esters, sulfonate esters, salicylate esters, succinic acid esters, sorbitan esters, and various types of amine salts . Examples of oily agents, extreme pressure agents, and anti-wear agents include zinc dialkyl dithiophosphate sulfide, zinc diallyl dithiophosphate sulfide, zinc dialkyldithiocarbamate sulfide, diallyl dithiocarbamate Zinc thiocarbamate sulfide, molybdenum dialkyl dithiophosphate sulfide, molybdenum diallyl dithiophosphate sulfide, molybdenum dialkyl dithiocarbamate sulfide, molybdenum diallyl dithiocarbamate sulfide , organic molybdenum complexes, olefin sulfides, triphenyl phosphate, triphenyl thiophosphate, tricresyl phosphate and other phosphates, and sulfurized oils/fats, etc. Examples of solid lubricants include molybdenum disulfide, graphite, boron nitride, melamine cyanurate, PTFE (polytetrafluoroethylene), tungsten disulfide, graphite fluoride, and calcium phosphate. Examples of metal deactivators include N,N'-disalicylidene-1,2-diaminopropane, benzotriazole, benzimidazole, benzothiazole, thiadiazole and the like. Examples of polymers include polybutene, polyisobutylene, 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 succinimide and the like. However, these examples are not intended to limit the invention.

Then, an explanation is provided for the amounts of the respective components of the grease composition involved in this mode of the present invention. Unless otherwise stated, % refers to mass percent.

The blending amount of the base oil is preferably 60-95% by mass, more preferably 70-90% by mass and still more preferably 75-90% by mass, out of 100% by mass of the total grease composition.

The amount of the thickener {such as a urea compound (for example, an alkyldiurea compound)} to be incorporated is preferably 1 to 20% by mass, more preferably 2 to 17% by mass and more preferably 3 to 15% by mass, of the total grease composition 100% by mass.

The amount of hydroxyl-containing poly(meth)acrylate incorporated is preferably 2-20% by mass and more preferably 4-10% by mass, based on 100% by mass of the total grease composition.

The amount of other additives is, for example, 0.03 to 20% by mass (the sum of these optional components), with the total grease composition being 100% by mass.

A particularly preferred blending embodiment (especially considering the thickener and hydroxyl-containing PMA) is that, considering the thickener type is the above (2-1) to (2-3), the thickener content = 7.5- 15% by mass (more preferably 10-15% by mass), and, in the case where the hydroxyl-containing PMA is (hydroxyl value=20-50, weight-average molecular weight=1.0×104 to 2.0×104), the hydroxyl-containing PMA content = 7.5-15% by weight.

The grease composition of this mode of the present invention can be produced by a generally used grease production method, and is not limited, but as an example of a method of producing a urea grease composition, by 1 mol of diisocyanate as a raw material for a urea thickener The diurea thickener obtained by reacting with 2mol primary monoamine, or the tetraurea grease thickener obtained by reacting 2mol diisocyanate as urea thickener raw material with 1mol primary diamine and 2mol primary monoamine, or obtained by reacting as Raw materials for urea thickeners Triurea-monocarbamate obtained by reacting 2 mol of diisocyanate, 1 mol of primary diamine, 1 mol of primary monoamine and 1 mol of monoalcohol, synthesized in each case with base oil in a grease preparation kettle , to produce the grease used. A more specific production method related to the synthesis reaction of special thickeners in base oils: the temperature is raised to a temperature of about 180 ° C, after which cooling is carried out, and the additive {hydroxyl-containing poly The (meth)acrylate derivative} was incorporated and mixed thoroughly, after which the mixture was cooled to room temperature. Thereafter, a uniform grease composition can be obtained with a kneading machine (such as a three-roll mill, etc.).

The dropping point of the grease composition in this mode of the invention is preferably at least 180°C, more preferably at least 210°C, still more preferably at least 250°C and especially above or above 260°C. If the dropping point of the grease composition is at least 180° C., it is considered possible to suppress occurrence of lubricating problems such as loss of viscosity at high temperature with accompanying leakage or seizure. The dropping point refers to the temperature at which there is a breakdown of the thickener structure in a lubricating grease having viscosity as the temperature increases. The measurement of the dropping point can be performed in accordance with JIS K22208.

In the consistency test, the consistency of the grease in this mode of the present invention is preferably 000 to 6 (85-475), more preferably 0 to 4 (175-385), and still more preferably 1 to 3 ( 220-340). The consistency indicates the physical hardness of the grease. In consistency measurement, the measurement of used needle penetration can be performed in accordance with JIS K22207.

The friction test is based on the high-speed four-ball wear test in ASTM D2596, using a steel ball bearing for 30 minutes under the conditions of a speed of 1200rpm, a load of 40kgf and an ambient temperature (no temperature control), and then evaluated by the diameter of the wear scar on the stationary ball .

The grease composition of this mode of the present invention can not only be used for generally used machinery, bearings and gears, etc., but it can also exhibit excellent performance under such severe conditions such as high temperature conditions. For example, in the case of motor vehicles, it can be advantageously used for starters, alternators, various types of starter units and other engine peripherals, drive shafts, constant velocity joints (CVJs), roller bearings, clutches and other areas of the powertrain, electric control (EPS), braking equipment, ball joints, door hinges, handles, cooling fan motors, brake expanders and various other types of components etc. In addition, it is suitable for various lubrication areas of excavators, bulldozers, cranes and other types of construction machinery, and for the railway industry or the paper industry, or forestry equipment, agricultural machinery, chemical plants, wind turbines, electric generators, drying Furnaces, copiers, railway vehicles and seamless pipe and screw joints, etc., especially in high temperature/high load places. Other suggested applications include hard disk bearings, plastic lubrication, cylinder grease, etc. Satisfactory adjustments to the above applications are also possible.

Example

Hereinafter, the present invention is explained in more detail by working examples and comparative examples, but the present invention is not limited in any way by the examples provided.

The starting materials for the working examples and comparative examples are as follows.

thickener raw material

Regarding thickeners A and B, diurea components having the following chemical structures were used as thickeners.

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

(In these formulas, _R2 is a diphenylmethane group and _R1 is an octacarbonyl group, _R3 is a dodecyllauryl group and _R4 is a hexacarbonyl group.)

Thickener D: This is commercially available lithium 12-hydroxystearate for industrial use.

Base Oil A to C

Base Oil A: This is an alkane mineral oil obtained by dewaxing/solvent refining, and belongs to Group I; its kinematic viscosity is 14.28 mm ² /s at 100°C and 144.9 mm ² /s at 40°C; and its viscosity index It is 96.

Base oil B: This is a poly-α-olefin (PAO) synthetic oil belonging to Group IV, and it contains a mixture of low-viscosity PAO and high-viscosity PAO in order to adjust the kinematic viscosity at 100°C to 15.4 mm ² /s. The kinematic viscosity of the PAO mixture was 118.9 mm ² /s at 40°C, while its viscosity index was 136.

Base Oil C: This is an oil obtained by the GTL (Gas to Liquid) process, synthesized by the FischerTropsch method, and belongs to Group III; its kinematic viscosity is 8.2 mm ² /s at 100°C and 47.9 mm ² /s at 40°C ; while its viscosity index is 144.

additive

Additive A: hydroxyl-containing PMA (trade name: Aclube A-1070, manufactured by Sanyo Chemical Industries Ltd; Mw=1.7×10 ⁴ , hydroxyl value 30)

Additive B: PMA without hydroxyl group (trade name: Aclube V-815, manufactured by Sanyo Chemical Industries Ltd; Mw=2.1×10 ⁴ )

Additive C: PMA without hydroxyl group (trade name: Aclube812, manufactured by Sanyo Chemical Industries Ltd; Mw=3.3×10 ⁴ )

Additive D: PMA without hydroxyl group (trade name: Aclube C728, manufactured by Sanyo Chemical Industries Ltd; Mw=4.5×10 ⁴ )

Additive E: Ethylene-α-olefin copolymer (trade name: Lucant HC100, manufactured by Mitsui Chemical Inc.)

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

Working Example 1

Raw materials, base oils and additives were prepared and measured in the proportions shown in Table 1, while greases were obtained by the general method for preparing urea greases according to Working Example 1. The molar ratio of diisocyanate and primary amine constituting the raw material of the diurea grease thickener used herein is a ratio of 1:2. In terms of the preparation method in detail, the pre-prepared Group I base oil, that is, 60 wt% of the total amount of base oil A, was introduced into the sealed grease test preparation kettle, and immediately thereafter the diphenylmethane used for the urea thickener - The 4,4'-diisocyanate starting material is added, raising the temperature to 50°C during stirring. Octylamine and laurylamine were then separately dissolved in the remaining 40% by weight of the Group I base oil and introduced back into the test preparation kettle to cause the reaction and formation of the diurea Type II thickener. Heating is then continued, raising the temperature to about 180°C to cause stabilization of the thickener structure. Subsequently, cooling was started, and during the cooling process at a temperature of 80° C., Additive A, ie, a hydroxyl-containing poly(meth)acrylate derivative, was added, after which thorough stirring and mixing was carried out, and cooling was continued to room temperature. Thereafter, a homogeneous grease of Working Example 1 was obtained with a three-roll mill.

Working Example 2

Raw materials, base oils and additives were prepared and measured in the proportions shown in Table 1, while greases were obtained by the general method for preparing urea greases according to Working Example 2. The molar ratio of diisocyanate and primary amine constituting the raw material of the diurea grease thickener used herein is a ratio of 1:2. In detailing the preparation method, 60 wt% of the pre-prepared synthetic oil, that is, the total amount of base oil B, was introduced into a sealed grease test preparation kettle, and immediately thereafter diphenylmethane-4 for urea thickener , The 4'-diisocyanate starting material was added, raising the temperature to 50°C during stirring. Octylamine was then dissolved in the remaining 40% by weight of the synthetic oil and introduced into the test preparation kettle to cause the reaction and formation of the diurea Type I thickener. Heating is then continued, raising the temperature to about 180°C to cause stabilization of the thickener structure. Subsequently, cooling was started, and during the cooling process at a temperature of 80° C., Additive A, ie, a hydroxyl-containing poly(meth)acrylate derivative, was added, after which thorough stirring and mixing was continued, and cooling to room temperature was continued. Thereafter, a homogeneous grease of Working Example 2 was obtained with a three-roll mill.

Working Example 3

Raw materials, base oils and additives were prepared and measured in the proportions shown in Table 1, while greases were obtained by the general method for preparing urea greases according to Working Example 3. The molar ratio of diisocyanate and primary amine constituting the raw material of the diurea grease thickener used herein is a ratio of 1:2. In detailing the preparation method, 60 wt% of the total amount of the previously-prepared Group III base oil, Base Oil C, was introduced into a sealed grease test preparation kettle, immediately after which diphenyl for urea thickener was added Methane-4,4'-diisocyanate feedstock, increasing temperature to 50°C during stirring. Octylamine was then dissolved in the remaining 40 wt% of the Group III base oil and introduced into the test preparation kettle to cause the reaction and formation of the diurea Type I thickener. Heating is then continued, raising the temperature to about 180°C to cause stabilization of the thickener structure. Subsequently, cooling was started, and during the cooling process at a temperature of 80° C., Additive A, ie, a hydroxyl-containing poly(meth)acrylate derivative, was added, after which thorough stirring and mixing was continued, and cooling to room temperature was continued. Thereafter, a homogeneous grease of Working Example 3 was obtained with a three-roll mill.

Working Examples 4-6

Raw materials, base oils and additives were prepared and measured at the ratios shown in Table 1, and greases were obtained by the general method for preparing urea greases according to Working Examples 4 to 6, respectively. The molar ratio of diisocyanate and primary amine constituting the respective raw materials of the diurea grease thickeners used herein is a ratio of 1:2. In detailing the preparation method, a pre-prepared Group I base oil, i.e. 60 wt% of the total amount of Base Oil A, was introduced into a sealed grease test preparation kettle, immediately after which diphenylmethane for urea thickener was added - 4,4'-diisocyanate raw material, during stirring the temperature was raised to 50°C. Then, octylamine and laurylamine were separately dissolved in the remaining 40 wt% of the Group I base oil and introduced again into the test preparation kettle to cause the reaction and form the diurea Type II thickener. Heating is then continued, raising the temperature to about 180°C to cause stabilization of the thickener structure. Subsequently, cooling was started, and during the cooling process at a temperature of 80° C., Additive A, ie, a hydroxyl-containing poly(meth)acrylate derivative, was added, after which thorough stirring and mixing was continued, and cooling to room temperature was continued. Thereafter, homogeneous greases of Working Examples 4 to 6 were each obtained with a three-roll mill. In working examples 4 to 6, the amount of base oil was balanced according to the different amounts of additives used, and the amount of thickener was likewise slightly adjusted.

Working Example 7

Raw materials, base oils and additives were prepared and measured in the proportions shown in Table 1, while greases were obtained by the general method for preparing urea greases according to Working Example 7. The molar ratio of diisocyanate and primary amine constituting the raw material of the diurea grease thickener used herein is a ratio of 1:2. In detailing the preparation method, a pre-prepared Group I base oil, i.e. 60 wt% of the total amount of Base Oil A, was introduced into a sealed grease test preparation kettle, immediately after which diphenylmethane for urea thickener was added - 4,4'-diisocyanate raw material, during stirring the temperature was raised to 50°C. Octylamine was then dissolved in the remaining 40% by weight of the Group I base oil and introduced into the test preparation kettle to cause the reaction and formation of the diurea Type I thickener. Heating is then continued, raising the temperature to about 180°C to cause stabilization of the thickener structure. Subsequently, cooling was started, and during the cooling process at a temperature of 80° C., Additive A, ie, a hydroxyl-containing poly(meth)acrylate derivative, was added, after which thorough stirring and mixing was continued, and cooling to room temperature was continued. Thereafter, a homogeneous grease of Working Example 7 was obtained with a three-roll mill.

Working Example 8

Raw materials, base oils and additives were prepared and measured in the proportions shown in Table 1, while greases were obtained by the general method for preparing urea greases according to Working Example 8. The molar ratio of diisocyanate and primary amine constituting the raw material of the diurea grease thickener used herein is a ratio of 1:2. In detailing the preparation method, the pre-prepared total amount of Group I base oil, Base Oil A, was introduced into a sealed grease test preparation kettle, immediately after which diphenylmethane-4 for urea thickener was added, 4'-Diisocyanate starting material, during stirring the temperature was raised to 50°C. Then, octylamine is mixed with synthetic oil, base oil B, laurylamine is mixed and dissolved in base oil C belonging to group III, and these are again introduced into the test preparation kettle to cause reaction and formation of diurea type II thickening agent. Heating is then continued, raising the temperature to about 180°C to cause stabilization of the thickener structure. Subsequently, cooling was started, and during the cooling process at a temperature of 80° C., Additive A, ie, a hydroxyl-containing poly(meth)acrylate derivative, was added, after which thorough stirring and mixing was continued, and cooling to room temperature was continued. Thereafter, a homogeneous grease of Working Example 8 was obtained using a three-roll mill.

Working Example 9

Raw materials, base oils and additives were prepared and measured in the proportions shown in Table 1, while greases were obtained by the general method for preparing urea greases according to Working Example 9. The molar ratio of diisocyanate and primary amine constituting the raw material of the diurea grease thickener used herein is a 1:2 ratio. In detailing the preparation method, a pre-prepared Group I base oil, i.e. 60 wt% of the total amount of Base Oil A, was introduced into a sealed grease test preparation kettle, immediately after which diphenylmethane for urea thickener was added - 4,4'-diisocyanate raw material, during stirring the temperature was raised to 50°C. Then, the aniline was mixed and dissolved in the remaining 40 wt% of the Group I base oil, and introduced into the test preparation kettle to cause the reaction and formation of the diurea Type III thickener. Heating is then continued, raising the temperature to about 180°C to cause stabilization of the thickener structure. Subsequently, cooling was started, and during the cooling process at a temperature of 80° C., Additive A, ie, a hydroxyl-containing poly(meth)acrylate derivative, was added, after which thorough stirring and mixing was continued, and cooling to room temperature was continued. Thereafter, a homogeneous grease of Working Example 9 was obtained using a three-roll mill.

Working Example 10

Prepare commercially available industrially available 12-hydroxystearate lithium and Group I base oil, i.e. base oil A, according to the ratio shown in Table 1, and introduce the entire amount of the base oil and 12-hydroxystearate lithium Seal the grease test kettle and raise the temperature to 230°C with stirring. After confirming that lithium 12-hydroxystearate was completely dissolved, the temperature was gradually lowered to 80°C. Additive A, the hydroxyl-containing poly(meth)acrylate derivative, was then added at this temperature of 80° C., after which thorough stirring and mixing was followed by continued cooling to room temperature. Thereafter, a homogeneous grease of Working Example 10 was obtained using a three-roll mill.

Comparative Example 1 to Comparative Example 3

Using the preparation method described in Working Example 6, thickener-forming reactions were carried out and comparative greases were respectively obtained, wherein Comparative Example 1 was a base grease into which no additive was blended. In Comparative Example 2, Additive B was incorporated. In Comparative Example 3, Additive C was incorporated.

Comparative Example 4 to Comparative Example 6

Using the preparation method described in Working Example 1, the thickener-forming reaction was carried out and comparative greases were respectively obtained, and 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. As can be seen from Table 1, with the greases referred to in Working Examples 1 to 10, excellent wear resistance performance (wear scar diameter 0.39-0.52) was obtained in each case.

Claims (10)

1. grease composition, it comprises base oil, thickening material and poly-(methyl) acrylate/ester that contains hydroxyl.

2. according to the grease composition of claim 1, wherein said thickening material is by reacting between isocyanic ester and primary amine the carbamide compound forming.

3. according to the grease composition of claim 2, wherein said carbamide compound is by two carbamide compounds react acquisition between vulcabond and uncle's monoamine; By four carbamide compounds that reaction obtains between vulcabond, primary diamines and uncle's monoamine; Or by reacting triuret-mono-carbamate compounds of acquisition between vulcabond, primary diamines, uncle's monoamine and an alcohol.

4. according to the grease composition of claim 2, wherein said carbamide compound is the compound of general formula (I) representative:

R ¹-NHCONH-R ²-NHCONH-R ³ (I)

R wherein ¹and R ³respectively represent C _8-12aliphatic hydrocarbon group, and R ²represent C _6-15divalent aromatic radical.

5. according to the grease composition of arbitrary aforementioned claim, wherein said poly-(methyl) acrylate/ester that contains hydroxyl is the C that has having as constituent monomers _1-20(methyl) alkyl acrylate of alkyl, and the multipolymer of the vinyl monomer of hydroxyl.

6. according to the grease composition of claim 5, wherein said have a C _1-20(methyl) alkyl acrylate of alkyl is to have C _8-20(methyl) alkyl acrylate of alkyl.

7. according to the grease composition of claim 5 or claim 6, the vinyl monomer of wherein said hydroxyl is selected from (methyl) vinylformic acid hydroxyalkyl (C _2-6) ester, one-or two-hydroxyalkyl (C _1-4(methyl) acrylamide of)-replace, vinyl alcohol (hydrolysis by vinyl acetate unit forms), C _3-12enol, C _4-12alkene glycol, hydroxyalkyl (C _1-6) thiazolinyl (C _3-10) ether, the aromatic monomer of hydroxyl, polyhydroxy-alcohol, and the vinyl monomer that contains polyoxyalkylene hydrocarbon chain and hydroxyl.

8. according to the grease composition of any one in claim 5 to 7, wherein said multipolymer has further constituent monomers, is selected from the monomer containing nitro, the vinyl monomer that contains primary, secondary or tertiary amino, amphoteric ethylene monomer and the monomer that contains nitrile group.

9. according to the grease composition of arbitrary aforementioned claim, the hydroxyl value that wherein contains poly-(methyl) acrylate/ester of hydroxyl is 20 to 50.

10. according to the grease composition of arbitrary aforementioned claim, the base oil that comprises 60 to 95 quality %, the thickening material of 1-20 quality %, and poly-(methyl) acrylate/ester that contains hydroxyl of 2-20 quality %, total grease composition is 100 quality %.