JP2001089785A - Lubricating oil composition for rotary gas compressor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lubricating oil composition for rotary gas compressor, not generating a trouble of clogging its filter caused by a sludge even on using it in a rotary gas compressor having an extremely excellent mist separation system exhibiting its mist separating capacity of <=0.02 g/Nm3 stray mist amount. SOLUTION: In this lubricating oil composition, (A) a lubricating base oil having an oxidation stability of >=50 min RBOT value and containing <0.09 mass % sulfur content is used as the base oil, and contains (B) an antirust agent.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a lubricating oil composition for a rotary gas compressor BACKGROUND OF THE INVENTION, details used for rotating the gas compressor having a mist system mist separation capacity is less than Sutoremisuto weight 0.02 g / Nm ³ Lubricating oil composition to be used.

[0002]

2. Description of the Related Art Rotation of a vane type, a screw type, a scroll type, etc. for compressing gaseous substances such as air, nitrogen gas, oxygen gas, ammonia gas, carbon dioxide gas, hydrocarbon gas, combustion exhaust gas, combustion gas, etc. Development of lubricating oil used in compressors has been focused on improving oxidation stability and reducing sludge generation. Therefore, conventional lubricating oils for rotary gas compressors are mainly blended with base oils such as highly refined mineral oils and antioxidants such as hindered phenols and aromatic amines. Through the use of selective and antioxidant technologies, sludge formation due to the lubricating oil itself has been minimized.

[0003]

However, in order to further improve the oxidation stability, it is necessary to rely on an increase in the amount of the antioxidant. However, in that case, sludge formation of the antioxidant itself becomes a problem, and a conflicting relationship arises between increasing the amount of the antioxidant and reducing sludge. Therefore, even though it has been considerably improved, this problem has been a significant hindrance in order to further improve the oxidation stability and extend the life of the lubricating oil. The sludge caused by the antioxidant in the lubricating oil is not caused by the lubricating oil itself, but is mixed with an externally mixed sludge precursor (precursor) or the sludge itself and a filter in the middle of the compressed gas flow in the compressor. And the filter may be clogged. However, the nominal diameter of the finished filter of the filter used in the conventional rotary gas compressor is relatively large, and as a result, the amount of stray mist that cannot be collected by the mist separation system is 0.02 g / Nm ³ or more. When the sludge generation due to the lubricating oil itself was sufficiently reduced, there was almost no fear of filter clogging.

However, in recent years, the tendency of cleanliness that dislikes mist in compressed gas has increased, and the fiber density of the filter has tended to increase.
It has been extended from 000 to 6000 hours to 6000 to 12000 hours, and the clogging trouble of the filter in the rotary gas compressor has increased. In such a situation, it was practically impossible to extend the life of the lubricating oil by increasing the amount of the antioxidant, since the amount of sludge would further increase. The problem of filter clogging due to sludge caused by antioxidants in the lubricating oil or from sludge precursors or sludge mixed from the outside cannot be solved by conventional lubricating oil for rotary gas compressors. The development of a new lubricating oil for rotary gas compressors has been desired.

It is an object of the present invention to provide a filter for clogging with sludge even when used in a rotary gas compressor having an extremely excellent mist separation system having a mist separation capacity of less than 0.02 g / Nm ^3. An object of the present invention is to provide a lubricating oil composition for a rotary gas compressor that does not cause the above trouble.

[0006]

The inventor of the present invention has conducted various studies to solve the above-mentioned problems of the conventional lubricating oil for rotary gas compressors. As a result, the oxidation stability of the base oil having an RBOT value of 50 minutes or more was obtained. Using a lubricating base oil having a sulfur content of less than 0.09% by mass and containing a specific additive as a lubricating oil for a rotary gas compressor As a result, they have found that the above problems can be solved, and have completed the present invention.

The invention according to claim 1 of the present invention is a lubricating oil composition for a rotary gas compressor having a mist separation system having a mist separation capacity of less than 0.02 g / Nm ^{3 in a} mist amount, The lubricating oil composition uses, as a base oil, (A) a lubricating base oil having an RBOT value of 50 minutes or more and having a sulfur content of less than 0.09% by mass, and B) It is intended to provide a lubricating oil composition for a rotary gas compressor characterized by containing a rust inhibitor.

According to a second aspect of the present invention, there is provided the lubricating oil composition for a rotary gas compressor according to the first aspect, wherein the rust inhibitor (B) is a polybasic acid or an ester thereof, or a polybasic acid or an ester thereof. It is at least one compound selected from the group consisting of a polyhydric alcohol ester and an amine or a salt thereof.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the contents of the present invention will be described in more detail. As the lubricating base oil (A) in the lubricating oil composition for a rotary gas compressor of the present invention, a mineral lubricating base oil and / or a synthetic lubricating base oil can be used. However, the properties of the lubricating base oil (when two or more lubricating base oils are mixed and used as a base oil, the properties of the base oil after mixing) are as follows:
The RBOT value is 50 minutes or more, preferably 60 minutes or more, and the sulfur content is less than 0.09% by mass, preferably less than 0.05% by mass, more preferably less than 0.01% by mass. is necessary.

When a lubricating base oil having an RBOT value of less than 50 minutes or a sulfur content of 0.09% by mass or more is used, in order to compensate for insufficient oxidation stability, A large amount of antioxidant is required, which may cause an increase in sludge, which is not preferable.

Note that the RBOT value referred to here is JIS.
K 2514-1993 means a value measured in accordance with "6. Rotating cylinder-type oxidation stability test method" of "Lubricating oil-oxidation stability test method", and on the other hand, the sulfur content referred to herein. Means a value measured according to "4. Microcoulometric titration oxidation method" of JIS K2541-1996 "Crude oil and petroleum products-Sulfur content test method".

As the mineral oil-based lubricating base oil, for example, a lubricating oil fraction obtained by distilling crude oil under normal pressure and reduced pressure is subjected to solvent removal, solvent extraction, hydrocracking, and solvent removal. A paraffinic or naphthenic oil, normal paraffin, or the like, which is purified by appropriately combining purification treatments such as contact dewaxing, hydrorefining, sulfuric acid washing, and clay treatment can be used.

Examples of the synthetic lubricating base oil include, for example, propylene oligomer, polybutene, polyisobutylene, 1-octene oligomer, 1-decene oligomer, ethylene and propylene cooligomer, and ethylene and 1-octene. Poly-α-olefins such as cooligomers, ethylene and 1-decene cooligomers or hydrides thereof; isoparaffins; monoalkylbenzenes;
Alkylbenzenes such as dialkylbenzene and polyalkylbenzene, alkylnaphthalenes such as monoalkylnaphthalene, dialkylnaphthalene and polyalkylnaphthalene; dioctyl adipate, di-2-ethylhexyl adipate, diisodecyl adipate, ditridecyl adipate, di-2-ethylhexyl sebacate, ditriene Dibasic acid esters such as decyl glutarate; tribasic acid esters such as trimellitate; polyol esters such as trimethylolpropane caprylate, trimethylolpropaneperargonate, pentaerythritol 2-ethylhexanoate and pentaerythritol pelargonate ; Polyethylene glycol, polypropylene glycol, polyoxyethylene oxypropylene glycol, polyethylene Polyglycols such as glycol monoether, polypropylene glycol monoether, polyoxyethylene oxypropylene glycol monoether, polyethylene glycol diether, polypropylene glycol diether, polyoxyethylene oxypropylene glycol diether; monoalkyl diphenyl ether, dialkyl diphenyl ether, trialkyl Diphenyl ether, tetraalkyl diphenyl ether, polyalkyl (5 or more alkyl groups) diphenyl ether, monoalkyl triphenyl ether, dialkyl triphenyl ether, trialkyl triphenyl ether, tetraalkyl triphenyl ether, polyalkyl (5 or more alkyl groups) ) Triphenyl ether, tetraphenyl ether Monoalkyl tetraphenyl ether, dialkyl tetraphenyl ether, trialkyl tetraphenyl ether, tetraalkyl tetraphenyl ether, polyalkyl (5 or more alkyl groups) tetraphenyl ether, pentaphenyl ether, monoalkyl pentaphenyl ether, dialkyl pentaphenyl Phenyl ethers such as ether, trialkyl pentaphenyl ether, tetraalkyl tetraphenyl ether, and polyalkyl (5 or more alkyl groups) pentaphenyl ether; organic phosphoric acid esters such as tricresyl phosphate; silicone oil; ; Etc. can be used.

In the present invention, when the above-mentioned synthetic lubricating base oil is used as the component (A), RBO
It is necessary to use not only those having a T value of 50 minutes or more, but also those having a sulfur content of less than 0.09% by mass because many synthetic lubricating base oils contain sulfur compounds as impurities. There is. Among these mineral lubricating base oils and synthetic lubricating base oils, (A-1) alkyl naphthalene having at least one alkyl group, (A-2) A) an alkylphenyl ether having at least one alkyl group, (A-3) a silicone oil, and (A-4) a perfluoroether. It is preferably used.

The (A-1) alkylnaphthalene having at least one alkyl group specifically has 1 to 24 carbon atoms, preferably 1 to 4 carbon atoms. And preferably 1 to 3 alkyl naphthalenes.

The alkyl group may be linear or branched, for example, a methyl group, an ethyl group, an n-propyl group,
Isopropyl group, n-butyl group, isobutyl group, sec
-Butyl group, tert-butyl group, linear or branched pentyl group, linear or branched hexyl group, linear or branched heptyl group, linear or branched octyl group, Linear or branched nonyl group, linear or branched decyl group, linear or branched undecyl group, linear or branched dodecyl group, linear or branched tridecyl group, linear Linear or branched tetradecyl group, linear or branched pentadecyl group, linear or branched hexadecyl group, linear or branched heptadecyl group, linear or branched octadecyl group, linear Linear or branched nonadecyl group, linear or branched icosyl group, linear or branched henicosyl group, linear or branched docosyl group, linear or branched tricosyl group, linear And branched tetracosyl groups.

As the alkylnaphthalene, those having at least one straight-chain or branched long-chain alkyl group having 8 to 20 carbon atoms are preferable from the viewpoint of excellent lubricity and cooling property, and particularly preferable are those having 8 carbon atoms. Mono-long-chain alkylnaphthalene, mono-long-chain alkylmethylnaphthalene, mono-long-chain alkyldimethylnaphthalene having 1 to 20 linear or branched long-chain alkyl groups; linear or branched having 8 to 20 carbon atoms Di-long-chain alkylnaphthalenes having two long-chain alkyl groups, di-long-chain alkylmethylnaphthalenes, and mixtures thereof are preferably used.

On the other hand, the alkylphenyl ether having at least one (A-2) alkyl group herein specifically includes an alkyl group having 1 to 24 carbon atoms, preferably 1 to 20 carbon atoms. ~ 7, preferably 1-4
Examples of the phenyl ether skeleton include diphenyl ether, triphenyl ether and tetraphenyl ether.

The alkyl group may be linear or branched, for example, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, s
ec-butyl group, tert-butyl group, linear or branched pentyl group, linear or branched hexyl group, linear or branched heptyl group, linear or branched octyl group, A linear or branched nonyl group, a linear or branched decyl group,
Linear or branched undecyl, linear or branched dodecyl group, linear or branched tridecyl group, linear or branched tetradecyl group, linear or branched pentadecyl group,
Straight-chain or branched hexadecyl group, straight-chain or branched heptadecyl group, straight-chain or branched octadecyl group, straight-chain or branched nonadecyl group, straight-chain or branched icosyl group, Examples include a linear or branched henicosyl group, a linear or branched docosyl group, a linear or branched tricosyl group, a linear or branched tetracosyl group, and the like.

As the alkylphenyl ether,
From the viewpoint of excellent lubricating properties and cooling properties, those having at least one linear or branched long-chain alkyl group having 8 to 20 carbon atoms are preferable, and particularly, those having 8 to 20 carbon atoms are linear or branched. Mono-long-chain alkyl diphenyl ether having one linear long-chain alkyl group, mono-long-chain alkyl triphenyl ether, mono-long-chain alkyl tetraphenyl ether; two linear or branched long-chain alkyl groups having 8 to 20 carbon atoms Dilong chain alkyl diphenyl ether, di long chain alkyl triphenyl ether, di long chain alkyl tetraphenyl ether; tri long chain alkyl diphenyl ether having 3 straight or branched long chain alkyl groups having 8 to 20 carbon atoms Tri-long-chain alkyltriphenyl ethers, tri-long-chain alkyltetraphenyl ethers; linear or branched having 8 to 20 carbon atoms Tetra long chain alkyl ether having four chain alkyl group, tetra-long-chain alkyl triphenyl ether, tetra long chain alkyl tetraphenyl ether; and mixtures thereof are preferably used.

On the other hand, as the silicone oil (A-3) used herein, those having various structures are used. Preferably, one or two or more dialkylpolysiloxanes represented by the following general formula (1) are used. A mixture is used.

[0022]

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In the formula (1), R ^{1 to} R ⁴ each independently represent a linear or branched alkyl group having 1 to 4 carbon atoms, and a represents an integer of 2 or more. . As R ^{1 to} R ⁴ , specifically, a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group,
Examples thereof include a sec-butyl group and a tert-butyl group. Among them, a methyl group or an ethyl group is preferable, and a methyl group is more preferable.

On the other hand, as the (A-4) perfluoroether used herein, those having various structures are used, and preferably one or two of perfluoroether represented by the following general formula (2) is used. The above mixture is used.

[0025]

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In the formula (2), R ⁵ and R ⁶ each independently represent a fluorine atom or a linear or branched perfluoroalkyl group having 1 to 4 carbon atoms; Indicates an integer.

Specific examples of R ⁵ and R ⁶ include a fluorine atom, a perfluoromethyl group, a perfluoroethyl group, an n-perfluoropropyl group, an isoperfluoropropyl group, an n-perfluorobutyl group, Perfluorobutyl group, sec-perfluorobutyl group, tert
A perfluorobutyl group, and among them, a fluorine atom, a perfluoromethyl group or a perfluoroethyl group is preferable, and a fluorine atom or a perfluoromethyl group is more preferable.

As R ⁷ , specifically, perfluoromethylene, perfluoroethylene, perfluorotrimethylene, perfluoropropylene, perfluorotetramethylene, perfluorobutylene, perfluoro-1 , 2-dimethylethylene group, perfluoro-1-methyltrimethylene group, perfluoro-2-methyltrimethylene group and the like. In the (A-4) perfluoroether, an oxyperfluoroalkylene group having a different structure such as an oxyperfluoromethylene group and an oxyperfluoropropylene group may be present in one molecule. In that case, the oxyperfluoroalkylene groups having different structures may be randomly copolymerized, alternately copolymerized, or block copolymerized.

These mineral oil-based lubricating base oils and synthetic lubricating base oils may be used alone, or two or more base oils selected from these may be used in combination at any mixing ratio. May be used.

As described above, when two or more lubricating base oils are used as a mixture in the present invention,
It is sufficient that the properties of the base oil after mixing satisfy the condition that the RBOT value is 50 minutes or more and the sulfur content is less than 0.09% by mass. Therefore, a mineral lubricating base oil or a synthetic lubricating base oil that does not satisfy the conditions that the RBOT value alone is 50 minutes or more and the sulfur content is less than 0.09% by mass, that is, the RBOT value alone is 50% Mineral oil base oil or synthetic lubricating base oil having a sulfur content of less than 0.09% by mass or more as long as the base oil properties after mixing satisfy the above conditions. Mixing and using a base oil may be used at all.

The viscosity of the base oil used in the present invention (when two or more lubricating base oils are mixed and used as a base oil, indicates the properties of the base oil after mixing) is arbitrary, but the lubricity ,
In general, the kinematic viscosity at 40 ° C. is preferably 5 to 150 mm ² / S, more preferably 10 to 150 mm ² in terms of excellent cooling properties (heat removal properties) and little friction loss due to stirring resistance.
It is desirable to use one having a thickness of up to 110 mm ² / S.

The component (B) in the lubricating oil composition for a rotary gas compressor of the present invention is a rust inhibitor. As the rust inhibitor herein, any compound used as a rust inhibitor for lubricating oil, for example, a polybasic acid or an ester thereof,
Polyhydric alcohol esters, amines or salts thereof, organic phosphites, organic phosphates, metal organic sulfonates, metal organic phosphates, and the like can be used, and among these, filter clogging is particularly prevented. (B-1) Polybasic acid or ester thereof (B-2) Polyhydric alcohol ester (B-3) One or more compounds selected from amines or salts thereof Is preferred.

Specific examples of the polybasic acid (B-1) include alkyl succinic acid, alkenyl succinic acid, citric acid and the like. More specifically, examples of the alkyl succinic acid and alkenyl succinic acid here include a compound represented by the following general formula (3) or an anhydride thereof.

[0034]

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In the above general formula (3), R ⁸ is a group having 6 carbon atoms.
To 100, preferably an alkyl or alkenyl group having 8 to 80 carbon atoms. The method for producing the alkyl or alkenyl succinic acid is not limited at all, but may be, for example, 6 to 100 carbon atoms, preferably 8 to 9 carbon atoms.
Polyolefins such as α-olefins, propylene oligomers, polybutenes, and ethylene-propylene copolymers of No. 80 can be easily obtained by reacting with maleic anhydride. Examples of citric acid include a compound represented by the following formula (4) or an anhydride thereof.

[0036]

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On the other hand, as the ester of the polybasic acid referred to in (B-1), specifically, an alkyl or alkenyl succinic acid represented by the above general formula (3) or the above general formula (3) )), And an esterified product of a polybasic acid such as citric acid and an aliphatic monoalcohol having 1 to 30, preferably 1 to 22 carbon atoms or a polyhydric alcohol having 2 to 50 carbon atoms. it can. The aliphatic monoalcohol having 1 to 30 carbon atoms may be a linear aliphatic monohydric alcohol or a branched aliphatic monohydric alcohol. Further, a saturated aliphatic monohydric alcohol may be used, or an unsaturated aliphatic monohydric alcohol may be used.

Specifically, methyl alcohol, ethyl alcohol, propyl alcohol, butyl alcohol, pentyl alcohol, hexyl alcohol, octyl alcohol, nonyl alcohol, decyl alcohol, undecyl alcohol, dodecyl alcohol, tridecyl alcohol, tetradecyl alcohol, Pentadecyl alcohol, hexadecyl alcohol, heptadecyl alcohol, octadecyl alcohol, nonadecyl alcohol,
Alkyl alcohols such as icosyl alcohol, henycosyl alcohol and docosyl alcohol (the alkyl group may be linear or branched); pentenyl alcohol, hexenyl alcohol, heptenyl alcohol, octenyl alcohol, nonenyl alcohol, Cenyl alcohol, undecenyl alcohol, dodecenyl alcohol,
Tridecenyl alcohol, tetradecenyl alcohol,
Alkenyl alcohols such as pentadecenyl alcohol, hexadecenyl alcohol, heptadecenyl alcohol, octadecenyl alcohol, nonadecenyl alcohol, icosenyl alcohol, henicocenyl alcohol, docosenyl alcohol ( The alkenyl group may be straight-chain or branched, and one of the double bonds is also arbitrary.).

Examples of the polyhydric alcohol having 2 to 50 carbon atoms include ethylene glycol, propylene glycol, butylene glycol, pentylene glycol, hexylene glycol, heptylene glycol, octylene glycol, glycerin, Trimethylolethane, trimethylolpropane, pentaerythritol,
Not only sorbitan and the like but also those having 2 to 5 carbon atoms.
Within the range of 0, a dimer of these polyhydric alcohols,
Trimer, tetramer or higher multimer, specifically, diethylene glycol, triethylene glycol, tetraethylene glycol or higher polyethylene glycol, dipropylene glycol, tripropylene glycol, tetrapropylene glycol or higher polypropylene glycol, dibutylene glycol , Tributylene glycol, tetramer or higher polybutylene glycol, diglycerin, triglycerin, tetramer or higher polyglycerin, di (trimethylolethane), tri (trimethylolethane), tetramer or higher poly (trimer) Methylolethane), di (trimethylolpropane), tri (trimethylolpropane),
Tetramer or higher poly (trimethylolpropane), di (pentaerythritol), tri (pentaerythritol), tetra (pentaerythritol), di (sorbitan), tri (sorbitan), tetramer or higher poly (sorbitan), etc. Can be exemplified.

As the ester of the polybasic acid, two or more carboxyl groups of the above-mentioned polybasic acids such as alkylsuccinic acid, alkenylsuccinic acid and citric acid are all esterified with monoalcohol or polyhydric alcohol. Or a partial ester in which one or two carboxyl groups are esterified with a mono- or polyhydric alcohol and one or two carboxyl groups remain in the form of a free acid. In the present invention, any of them may be used, and a mixture thereof may be used.

In the esterification, a polyhydric alcohol,
For example, when a dihydric alcohol is used, a so-called monotype polybasic acid ester in which only one end of the dihydric alcohol is esterified with a polybasic acid, and both ends of the polyhydric alcohol are esterified with separate polybasic acids. Although there is a so-called bis-type polybasic acid ester, in the present invention,
Any of them may be used, and a mixture thereof may be used.

As the component (B-1), succinic acid or citric acid having an alkyl or alkenyl group having 8 to 80 carbon atoms and an aliphatic group having 1 to 22 carbon atoms are considered to be excellent in rust prevention performance. Monoalcohol or C2-50
Is preferably used as a partial ester with a polyhydric alcohol (including a polymer of a dimer or higher polyhydric alcohol), and a succinic acid or citric acid having an alkyl group or an alkenyl group having 8 to 80 carbon atoms, Partial esters with 2 to 50 polyhydric alcohols (including multimers of dihydric or higher polyhydric alcohols) are more preferably used.

On the other hand, examples of the polyhydric alcohol ester referred to in (B-2) include one or more polyhydric alcohols selected from glycerin, trimethylolethane, trimethylolpropane, pentaerythritol and sorbitan. Examples thereof include partial esters of fatty acids having 10 to 22 carbon atoms. Here, the partial ester means an ester in which at least one or more of the hydroxyl groups in the polyhydric alcohol remains in the form of a hydroxyl group which is not esterified.

The fatty acid used herein may be a saturated aliphatic carboxylic acid or an unsaturated aliphatic carboxylic acid, and may be a linear aliphatic carboxylic acid or a branched aliphatic carboxylic acid. Specifically, for example, decanoic acid, undecanoic acid, dodecanoic acid, tridecanoic acid, tetradecanoic acid, pentadecanoic acid, hexadecanoic acid, heptadecanoic acid, octadecanoic acid, nonadecanoic acid, eicosanoic acid, heneicosanoic acid,
Saturated aliphatic carboxylic acids such as docosanoic acid (the saturated aliphatic group may be linear or branched); decenoic acid, undecenoic acid, dodecenoic acid, tridecenoic acid, tetradecenoic acid, pentadecenoic acid, hexadecenoic acid, heptadecenoic acid, Unsaturated aliphatic carboxylic acids such as octadecenoic acid, nonadecenoic acid, eicosenoic acid, heneicosenoic acid and docosenoic acid (unsaturated aliphatic groups may be linear or branched, and the position of the double bond is arbitrary); And mixtures thereof, but octadecenoic acid is preferred, and oleic acid is most preferably used from the viewpoint of excellent rust prevention performance.

As the component (B-2), more specifically, glycerin monododecanoate (glycerin monolaurate), glycerin monoisolaurate, glycerin didodecanoate (glycerin dilaurate), glycerin diisolaurate Glycerin monotetradecanoate (glycerin monomyristate), glycerin monoisomyristate, glycerin ditetradecanoate (glycerin dimyristate), glycerin diisomyristate, glycerin monohexadecanoate (glycerin monopalmitate) ), Glycerin monoisopalmitate, glycerin dihexadecanoate (glycerin dipalmitate), glycerin diisopalmitate, glycerin monooctadecanoate (glycerin monostearate), glycerin Monoisostearate, glycerin dioctadecanoate (glycerin distearate), glycerin diisostearate, glycerin monooctadesenoate (glycerin monooleate), glycerin monoisooleate, glycerin dioctadecenoate ( Glycerin partial esters such as glycerin dioleate) and glycerin diisooleate; trimethylolethane monododecanoate (trimethylolethane monolaurate), trimethylolethane monoisolaurate, trimethylolethanedidodecanoate (trimethylolethane monolaurate); (Methylolethanedilaurate), trimethylolethanediisolaurate, trimethylolethane monotetradecanoate (trimethylolethane monomyristate), trimethylolethane monoisomyris , Trimethylolethaneditetradecanoate (trimethylolethanedimyristate), trimethylolethanediisomyristate, trimethylolethane monohexadecanoate (trimethylolethane monopalmitate), trimethylolethane ethane monoiso Palmitate, trimethylolethanedihexadecanoate (trimethylolethanedipalmitate), trimethylolethanediisopalmitate, trimethylolethane monooctadecanoate (trimethylolethane monostearate), trimethylolethane monoisoate Stearate, trimethylolethanedioctadecanoate (trimethylolethanedistearate), trimethylolethanediisostearate, trimethylolethane monooctadecenoate (trimethylolethanediisostearate) Methylolethane monooleate),
Trimethylolethane partial esters such as trimethylolethane monoisooleate, trimethylolethanedioctadecenoate (trimethylolethanedioleate), and trimethylolethanediisooleate; trimethylolpropane monododecanoate (trimethylol) Propane monolaurate), trimethylolpropane monoisolaurate, trimethylolpropanezide decanoate (trimethylolpropanedilaurate), trimethylolpropanediisolaurate, trimethylolpropanemonotetradecanoate (trimethylolpropane monomyristate) ), Trimethylolpropane monoisomyristate, trimethylolpropaneditetradecanoate (trimethylolpropanedimyristate),
Trimethylolpropane diisomyristate, trimethylolpropane monohexadecanoate (trimethylolpropane monopalmitate), trimethylolpropane monoisopalmitate, trimethylolpropane dihexadecanoate (trimethylolpropane dipalmitate), Trimethylolpropane diisopalmitate,
Trimethylolpropane monooctadecanoate (trimethylolpropane monostearate), trimethylolpropane monoisostearate, trimethylolpropane dioctadecanoate (trimethylolpropane distearate), trimethylolpropane diisostearate, Trimethylolpropane monooctadecenoate (trimethylolpropane monooleate), trimethylolpropane monoisooleate, trimethylolpropane dioctadecenoate (trimethylolpropanedioleate), trimethylolpropanediisooleate, etc. Trimethylolpropane partial ester of pentaerythritol monododecanoate (pentaerythritol monolaurate), pentaerythritol monoisolaurate, Taerythritol didodecanoate (pentaerythritol dilaurate), pentaerythritol diisolaurate, pentaerythritol tridodecanoate (pentaerythritol trilaurate), pentaerythritol triisolaurate, pentaerythritol monotetradecanoate (pentaerythritol monomilli) Pentaerythritol monoisomyristate, pentaerythritol ditetradecanoate (pentaerythritol dimyristate), pentaerythritol diisomyristate, pentaerythritol tritetradecanoate (pentaerythritol trimiristate), pentaerythritol tri Isomyristate, pentaerythritol monohexadecanoate (pentaerythritol Palmitate), pentaerythritol monoisopalmitate, pentaerythritol dihexadecanoate (pentaerythritol dipalmitate), pentaerythritol diisopalmitate, pentaerythritol trihexadecanoate (pentaerythritol tripalmitate), pentaerythritol tri Isopalmitate, pentaerythritol monooctadecanoate (pentaerythritol monostearate), pentaerythritol monoisostearate, pentaerythritol dioctadecanoate (pentaerythritol distearate), pentaerythritol diisostearate, pentaerythritol Trioctadecanoate (pentaerythritol tristearate), pentaerythritol triisosteate Allates, pentaerythritol monooctadecenoate (pentaerythritol monooleate), pentaerythritol monoisooleate, pentaerythritol dioctadecenoate (pentaerythritol dioleate), pentaerythritol diisooleate, pentaerythritol triocta Pentaerythritol partial esters such as decenoate (pentaerythritol trioleate) and pentaerythritol triisooleate; sorbitan monododecanoate (sorbitan monolaurate), sorbitan monoisolaurate, sorbitan didodecanoate (sorbitan dilaurate) , Sorbitan diisolaurate, sorbitan tridodecanoate (sorbitan trilaurate),
Sorbitan triisolaurate, sorbitan monotetradecanoate (sorbitan monomyristate), sorbitan monoisomyristate, sorbitan ditetradecanoate (sorbitan dimyristate), sorbitan diisomyristate, sorbitan tritetradecanoate ( Sorbitan triisomyristate), sorbitan triisomyristate, sorbitan monohexadecanoate (sorbitan monopalmitate), sorbitan monoisopalmitate, sorbitan dihexadecanoate (sorbitan dipalmitate), sorbitan diisopalmitate,
Sorbitan trihexadecanoate (sorbitan tripalmitate), sorbitan triisopalmitate, sorbitan monooctadecanoate (sorbitan monostearate), sorbitan monoisostearate, sorbitan dioctadedecanoate (sorbitan distearate) , Sorbitan diisostearate, sorbitan trioctadecanoate (sorbitan tristearate),
Sorbitan triisostearate, sorbitan monooctadecenoate (sorbitan monooleate), sorbitan monoisooleate, sorbitan dioctadecenoate (sorbitan dioleate), sorbitan diisooleate, sorbitan trioctadecenoate (Sorbitan trioleate) and sorbitan partial esters such as sorbitan triisooleate; and mixtures thereof are preferably used.

Further, as described above, glycerin monooleate, glycerin dioleate, trimethylolethane monooleate, trimethylolethanedioleate, trimethylolpropane monooleate, and trimethylolpropane are excellent in rust prevention performance. Dioleate, pentaerythritol monooleate, pentaerythritol dioleate, pentaerythritol trioleate, sorbitan monooleate, sorbitan dioleate, sorbitan trioleate, sorbitan trioleate, and mixtures thereof are more preferably used, and glycerin, which is monooleate, is more preferable. Monooleate, trimethylolethane monooleate, trimethylolpropane monooleate, pentaerythritol monooleate, sorbitan monooleate Beauty, etc. These mixtures are more preferably used.

On the other hand, examples of the amine or a salt thereof referred to in (B-3) include a primary amine or a secondary amine having a hydrocarbon group having 4 to 22 carbon atoms, and a combination of these amines and a C1 to C2 amine.
And a salt with an aliphatic carboxylic acid of No. 22. As the hydrocarbon group having 4 to 22 carbon atoms here, specifically, a butyl group, a pentyl group, a hexyl group, a heptyl group,
Alkyl groups such as octyl group, nonyl group, decyl group, undecyl group, dodecyl group, tridecyl group, tetradecyl group, pentadecyl group, hexadecyl group, heptadecyl group, octadecyl group, nonadecyl group, icosyl group, henycosyl group and docosyl group; The group may be straight-chain or branched); butenyl, pentenyl, hexenyl, heptenyl, octenyl, nonenyl, decenyl, undecenyl, dodecenyl, tridecenyl, tetradecenyl, pentadecenyl, hexadecenyl Alkenyl groups such as a group, heptadecenyl group, octadecenyl group, nonadecenyl group, icosenyl group, henicocenyl group, docosenyl group (alkenyl group may be linear or branched, and the position of double bond is arbitrary); cyclopentyl group , Cyclohexyl group, Cycloalkyl groups such as loheptyl group; methylcyclopentyl group, methylcyclohexyl group, methylcycloheptyl group, ethylcyclopentyl group, ethylcyclohexyl group, ethylcycloheptyl group, propylcyclopentyl group, propylcyclohexyl group, propylcycloheptyl group, butylcyclopentyl group Alkylcycloalkyl groups such as butylcyclohexyl group, butylcycloheptyl group, dimethylcyclopentyl group, dimethylcyclohexyl group, dimethylcycloheptyl group, diethylcyclopentyl group, diethylcyclohexyl group, diethylcycloheptyl group, etc. It may be branched, and the position of the bond to the cycloalkyl group is arbitrary.); An aryl group such as a phenyl group and a naphthyl group; a methylphenyl group (tolyl group) An alkylaryl group such as an ethylphenyl group, a propylphenyl group, a butylphenyl group, a dimethylphenyl group (xylyl group), or a diethylphenyl group (the alkyl group may be linear or branched, and the bonding position to the aryl group may be Phenylmethyl, phenylethyl, phenylpropyl, phenylbutyl, phenylpentyl,
Examples thereof include an arylalkyl group such as a phenylhexyl group (the alkyl group may be linear or branched, and the bonding position of the aryl group to the alkyl group is arbitrary). Among them, they are excellent in rust prevention performance. From the point, carbon number 6-1
Preferred are an alkyl group, alkenyl group, cycloalkyl group and alkylcycloalkyl group of No. 8.

Preferred examples of the primary amine of the component (B-3) include hexylamine, heptylamine, octylamine, nonylamine, decylamine, undecylamine, dodecylamine, tridecylamine, and the like.
Monoalkylamines such as tetradecylamine, pentadecylamine, hexadecylamine, heptadecylamine, and octadecylamine (the alkyl group may be linear or branched); hexenylamine, heptenylamine, octenylamine, nonenylamine, decenylamine, undecane Cenylamine, dodecenylamine, tridecenylamine, tetradecenylamine, pentadecenylamine,
Monoalkenylamines such as hexadecenylamine, heptadecenylamine and octadecenylamine (alkenyl groups may be linear or branched, and the position of the double bond is arbitrary); cyclohexylamine, cycloheptylamine Monocycloalkylamines such as methylcyclopentylamine, methylcyclohexylamine, methylcycloheptylamine, ethylcyclopentylamine, ethylcyclohexylamine, ethylcycloheptylamine;
Mono (alkylcycloalkyl) amines such as propylcyclopentylamine, propylcyclohexylamine, propylcycloheptylamine, butylcyclopentylamine, butylcyclohexylamine, butylcycloheptylamine, dimethylcyclopentylamine, and dimethylcyclohexylamine (where the alkyl group is linear) It may be branched, and the bonding position of the alkyl group to the cycloalkyl group is arbitrary.); And mixtures thereof.

Preferred examples of the secondary amine as the component (B-3) include alkylcycloalkylamines such as diethylcyclopentylamine, diethylcyclohexylamine, and diethylcycloheptylamine, dihexylamine, diheptylamine, and the like. Dioctylamine,
Dialkylamines such as dinonylamine, didecylamine, diundecylamine, didodecylamine, ditridecylamine, ditetradecylamine, dipentadecylamine, dihexadecylamine, diheptadecylamine, dioctadecylamine, etc. Or branched); dihexenylamine, diheptenylamine, dioctenylamine, dinonenylamine, didecenylamine, diundecenylamine, didodecenylamine, ditridecenylamine, ditetradecenylamine,
Dialkenylamines such as dipentadecenylamine, dihexadecenylamine, diheptadecenylamine and dioctadecenylamine (the alkenyl group may be linear or branched, and the position of the double bond is arbitrary. Dicycloalkylamines such as dicyclohexylamine and dicycloheptylamine; di (methylcyclopentyl) amine, di (methylcyclohexyl) amine, di (methylcycloheptyl) amine, di (ethylcyclopentyl) amine;
Di (ethylcyclohexyl) amine, di (ethylcycloheptyl) amine, di (propylcyclopentyl) amine, di (propylcyclohexyl) amine, di (propylcycloheptyl) amine, di (butylcyclopentyl) amine, di (butylcyclohexyl) amine , Di (butylcycloheptyl) amine, di (dimethylcyclopentyl) amine, di (dimethylcyclohexyl) amine, di (dimethylcycloheptyl) amine, di (diethylcyclopentyl) amine, di (diethylcyclohexyl) amine, di (diethylcycloheptyl) ) Di (alkylcycloalkyl) such as amines (the alkyl group may be linear or branched, and the bonding position of the alkyl group to the cycloalkyl group is arbitrary); and mixtures thereof.

The aliphatic carboxylic acid having 1 to 22 carbon atoms described above as a compound forming a salt of these amines may be a saturated aliphatic carboxylic acid or an unsaturated aliphatic carboxylic acid, or may be a linear aliphatic carboxylic acid. An acid or a branched aliphatic carboxylic acid may be used. Specifically, for example, acetic acid, propanoic acid, butanoic acid, pentanoic acid, hexanoic acid, heptanoic acid, octanoic acid, nonanoic acid, decanoic acid, undecanoic acid,
Saturated aliphatic carboxylic acids such as dodecanoic acid, tridecanoic acid, tetradecanoic acid, pentadecanoic acid, hexadecanoic acid, heptadecanoic acid, octadecanoic acid, nonadecanoic acid, eicosanoic acid, heneicosanoic acid, docosanoic acid, etc. May be branched); butenoic acid, pentenoic acid, hexenoic acid, heptenoic acid, octenoic acid, nonenoic acid,
Decenoic acid, undecenoic acid, dodecenoic acid, tridecenoic acid,
Unsaturated aliphatic carboxylic acids such as tetradecenoic acid, pentadecenoic acid, hexadecenoic acid, heptadecenoic acid, octadecenoic acid, nonadecenoic acid, eicosenoic acid, heneicosenoic acid and docosenoic acid (unsaturated aliphatic groups may be linear or branched; , The position of the double bond is also arbitrary); and a mixture thereof, and the like.
A saturated aliphatic carboxylic acid having 6 to 18 carbon atoms (the saturated aliphatic group may be linear or branched) or an unsaturated aliphatic carboxylic acid (the unsaturated aliphatic group may be linear or branched; , The position of the double bond is also arbitrary), and mixtures thereof.

As the form of the amine salt, a salt obtained by reacting 1 mol of a primary amine with 1 mol of an aliphatic carboxylic acid, or 1 mol of a primary amine and 2 mol of an aliphatic carboxylic acid are reacted. There is a salt obtained by reacting 1 mol of a secondary amine with 1 mol of an aliphatic carboxylic acid,
As the amine salt of the component (B-3), any of them can be used, and a mixture thereof can also be used.

Further, it goes without saying that the component (B) of the present invention includes a polybasic acid or its ester as the component (B-1), a polyhydric alcohol ester as the component (B-2) and Needless to say, a mixture obtained by mixing two or more compounds selected from the group consisting of the amine (B-3) and the salt thereof at an arbitrary mixing ratio can also be preferably used.

The content of the component (B) in the lubricating oil composition of the present invention is optional, but the lower limit of the content is usually limited in view of the excellent filter clogging prevention property and rust prevention performance. It is preferably 0.001% by mass, more preferably 0.01% by mass, and particularly preferably 0.05% by mass, based on the total amount. On the other hand, the upper limit of the content is
Based on the total amount of the composition, it is preferably 10.0% by mass, more preferably 7.0% by mass, and particularly preferably 5.0% by mass.

Further, in the lubricating oil composition for a rotary gas compressor of the present invention, in order to further enhance its various performances,
Further known lubricating oil additives, for example, antioxidants, metal-based detergents, ashless dispersants, corrosion inhibitors, antiwear agents, pour point depressants, defoamers, etc. alone or in combination of several types Can also be used.

As the antioxidant, any one generally used in lubricating oils such as phenolic compounds and amine compounds can be used. Specifically, alkylphenols such as 2,6-di-tert-butyl-4-methylphenol and bisphenols such as methylene-4,4-bis (2,6-di-tert-butyl-4-methylphenol) , Naphthylamines such as phenyl-α-naphthylamine, dialkyldiphenylamines, di-2
-Zinc dialkyldithiophosphates such as -ethylhexyldithiophosphate and the like.

Examples of the metal-based detergent include neutral, basic and overbased alkali metal sulfonates, alkali metal phenates, alkali metal salicylates, alkaline earth metal sulfonates, alkaline earth metal phenates, and the like. Alkaline earth metal salicylates and the like can be exemplified. Examples of the alkali metal include sodium and potassium, and examples of the alkaline earth metal include magnesium and calcium.

Examples of the ashless dispersant include not only ashless dispersants for so-called lubricating oils such as alkenylsuccinimide, polyalkenylpolyamine and benzylamine, but also polar monomers containing nitrogen in polymers such as polymethacrylates and polyacrylates. A so-called dispersion-type viscosity index improver into which is introduced can also be used.

Specific examples of the corrosion inhibitor include benzotriazole, thiadiazole and imidazole compounds.

As a wear inhibitor, for example, a sulfur compound or a phosphorus compound can be used. Specific examples of the sulfur-based compound include disulfides, sulfurized olefins, and sulfurized fats and oils. Specific examples of the phosphorus-based compound include phosphoric acid monoesters, phosphoric diesters, and phosphoric acid. Triesters, phosphite monoesters, phosphite diesters, phosphite triesters,
And salts of these esters with amines and alkanolamines.

Specific examples of the pour point depressant include polymethacrylate polymers compatible with the lubricating base oil used.

Specific examples of the defoaming agent include silicones such as dimethyl silicone.

The addition amount of these known additives is optional, but when used, the content thereof is usually based on the total amount of the lubricating oil composition in an antioxidant, a metal-based detergent and an ashless dispersant. 0.01 to 5.0% by mass; for corrosion inhibitors, usually 0.01 to 3.0% by mass; for antiwear agents, usually 0.1 to 5.0% by mass; for pour point depressants, Usually, 0.05 to 5.0% by mass;
0.0001-0.05% by mass;

The lubricating oil composition for a rotary gas compressor of the present invention has a mist separation capacity of 0.02 g / N of a stray mist.
m3 is used in a rotary gas compressor having a mist separation system of less than ³ , as long as the rotary gas compressor meets this condition, vane type, screw type, scroll type, etc., any rotary compression type It is applicable to the used gas compressor.

Further, the gas to be compressed is not particularly limited, and may be any gas such as air, nitrogen gas, oxygen gas, ammonia gas, carbon dioxide gas, hydrocarbon gas, combustion exhaust gas, and combustion gas. Applicable.

The rotary gas compressor having a mist separation system having a mist separation capacity of less than 0.02 g / Nm ³ in the present invention is defined as a discharge gas passing through the mist separation system of the rotary gas compressor. The amount of stray mist measured by the following method is 0.0
A rotary gas compressor that is less than 2 g / Nm ³ is meant.

That is, 1. At the outlet of the rotary gas compressor (the gas outlet after passing through the mist separation system of the compressor), two stray mist collecting filters 5, 6 shown in FIG. 1 (both are oil removal filters manufactured by CKD) (Use micro-eresa micro-note type filter 1144-2 / 3C-EY)
Combine the stray mist amount measuring device equipped with. Before bonding, each of the filters 5 and 6 for collecting stremist is put in a desiccator at 50 ° C. for 24 hours, weighed, and its dry weight (g) is measured. Note that the distance indicated by w in FIG. 1 is 1 m or less. 2. Close the valves 1 and 2 of the stray mist amount measuring device,
Further, the valves 3 and 4 are opened so that the discharge gas of the rotary gas compressor passes through the bypass line 9. 3. The discharge gas of the rotary gas compressor is passed through the bypass line 9 continuously for 2 hours or more, and it is confirmed that the discharge gas temperature of the gas flow meter 7 has reached a constant temperature (steady temperature state).
8 is a temperature sensor. 4. After confirming that the discharged gas is in a steady temperature state, open the valves 1 and 2 of the stray mist amount measuring device and close the valves 3 and 4, and discharge the stray mist from the rotary gas compressor for collecting two sets of stray mist. The filters 5 and 6 are allowed to pass continuously for 24 hours. At this time, the total passing gas amount (m ³ ) and the discharge gas temperature (° C.) of the gas flow meter 7 are recorded, and the total passing gas amount (Nm ³ ) in the standard state is obtained. 5. Set the filters 5 and 6 for collecting the stray mist after the test to 5
After being placed in a desiccator at 0 ° C. for 24 hours, it is weighed and the weight (g) after the test is determined. 6. The stray mist amount (g / Nm ³ ) of the rotating gas compressor tested by the following equation is obtained. The recovered oil content (g) is the difference between the total weight (g) of the two stremist collecting filters 5 and 6 after the test and the total weight (g) before the test.

Formula:

[0068]

EXAMPLES Hereinafter, the content of the present invention will be described more specifically with reference to Examples and Comparative Examples, but the present invention is not limited to these contents.

(Examples 1 to 8) For the lubricating oil composition for a rotary gas compressor according to the present invention having the composition (% by mass) shown in Table 1 and the properties of the base oil, the following filter differential pressure monitoring test was carried out. The results are also shown in Table 1. [Filter differential pressure monitor test] Rotating gas compressor KST6P manufactured by Kobe Steel, Ltd. using lubricating oil composition for rotating gas compressor
(The amount of stray mist measured by the method described above is 0.
01g / Nm ³ ) was continuously operated, and the differential pressure (kPa) before and after the mist filter provided in the compressor was measured after the operation time of 6000 hours and 9000 hours.

(Comparative Examples 1 to 3) For comparison, (A)
When the other base oils shown in Table 2 were used in place of the components, the same tests as in Examples 1 to 8 were performed.
It was noted in.

(Comparative Example 4) For comparison, the same tests as in Examples 1 to 8 were conducted for the case where the component (B) was not used, and the results are also shown in Table 2.

[0072]

[Table 1]

[0073]

[Table 2]

As is evident from the results in Tables 1 and 2, the lubricating oil compositions for rotary gas compressors (Examples 1 to 8) according to the present invention were compared with the compositions of Comparative Examples (1 to 4), The absolute value of the filter differential pressure in the test and the rate of increase due to the elapse of the operation time are low, indicating excellent performance in preventing filter clogging.

[0075]

According to the lubricating oil composition for a rotary gas compressor of the present invention, even when used in a rotary gas compressor having an extremely excellent mist separation ability as described above, troubles caused by filter clogging can be prevented. Demonstrates excellent performance that it does not occur.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing a stray mist amount measuring device.

[Explanation of symbols]

 1, 2, 3, 4 Valve 5, 6 Filter for collecting stray mist 7 Gas flow meter 8 Temperature sensor 9 Bypass line

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI theme coat ゛ (Reference) C10M 129/34 C10M 129/34 129/36 129/36 129/72 129/72 129/74 129/74 129 / 76 129/76 129/95 129/95 133/06 133/06 F04B 39/04 F04B 39/04 Z // C10N 20:00 C10N 20:00 Z 30:10 30:10 30:12 30:12 40 : 30 40:30

Claims (2)

[Claims] 1. The mist separation ability is equal to a streak mist amount of 0.
A lubricating oil composition for a rotary gas compressor having a mist separation system of less than 02 g / Nm ³ , wherein the lubricating oil composition has, as a base oil, (A) an oxidation stability performance of a RBOT value of 50 minutes or more, and A lubricating base oil having a sulfur content of less than 0.09% by mass and containing (B) a rust inhibitor. Composition. (B) The rust inhibitor is one or more compounds selected from the group consisting of polybasic acids or esters thereof, polyhydric alcohol esters and amines or salts thereof. The lubricating oil composition for a rotary gas compressor according to claim 1.