JP5256730B2 - Lubricating oil composition for metal working - Google Patents

Description

The present invention relates to a lubricating oil for metal working.

  Conventionally, mineral oils, animal and vegetable oils, and synthetic oils have been used as base oils for lubricating oils for metalworking oils. However, these base oils alone cannot sufficiently satisfy various performances necessary for metal processing, and performance has been improved by adding various additives.

  For example, a technique in which an alicyclic epoxy compound is contained in metal working oil for the purpose of improving workability during metal rolling and improving oil film removal is disclosed (Patent Document 1).

In addition to the above documents, as a technique for blending an epoxy compound into a lubricating oil, a technique for improving the cleanliness of engine oil by blending an alicyclic epoxy compound is disclosed (Patent Document 2).
Furthermore, it has been disclosed that a lubricating oil composition containing an alicyclic epoxy compound and an antioxidant in combination improves the thermal stability and high temperature cleanability of the lubricating oil and is suitable as a two-cycle engine oil. (Patent Document 3).
However, these Patent Documents 2 and 3 do not disclose the improvement of wear prevention performance by adding an epoxy compound to the lubricating oil composition.

JP 2006-299220 A JP 2000-008069 A JP-A-11-335688

It is an object to provide a lubricating oil composition for metal working having high wear prevention performance.

  As a result of intensive studies to solve the above problems, the present inventors have blended an epoxy compound having a specific structure with the base oil, so that the wear prevention performance, which is an important performance in metalworking lubricants, is achieved. Based on this finding, the present invention has been completed.

That is, the present invention provides the following lubricating oil.
(Claim 1)
At least one base oil selected from the group consisting of mineral oil, animal and vegetable oils and synthetic oils, and general formula (1)
[Wherein, R ¹ represents a substituent selected from Group A below, and R ² represents a substituent selected from Group A or Group B below.
A: Saturated aliphatic hydrocarbon group having an epoxy group having 16 to 22 carbon atoms B: Saturated aliphatic hydrocarbon group having 16 to 22 carbon atoms]
The lubricating oil composition for metalworking of Claim 1 formed by containing the at least 1 sort (s) of epoxy compound represented by these.
(Section 2)
Item 2. The lubricating oil composition for metalworking according to Item 1, wherein the content of the epoxy compound represented by the general formula (1) is 1 to 30%.
(Section 3)
Item 3. The lubricating oil composition for metalworking according to Item 1 or 2, wherein in General Formula (1), R ¹ and R ² are substituents selected from Group A.
(Section 4)
General formula (1)
[Wherein, R ¹ represents a substituent selected from Group A below, and R ² represents a substituent selected from Group A or Group B below.
A: Saturated aliphatic hydrocarbon group having an epoxy group having 16 to 22 carbon atoms B: Saturated aliphatic hydrocarbon group having 16 to 22 carbon atoms]
A method for improving the wear-preventing performance of a lubricating oil composition for metal working, comprising at least one epoxy compound represented by the formula:

  The present invention has been found that a lubricating oil composition comprising an epoxy compound having a specific structure and a base oil has high wear resistance. Since the lubricating oil composition has excellent wear resistance, it is suitable as a lubricating oil for metal working.

[Lubricating oil composition]
The lubricating oil composition for metal processing according to the present invention comprises a lubricating oil composition comprising at least one base oil selected from the group consisting of mineral oil, animal and vegetable oils and synthetic oils, and an epoxy compound represented by the above general formula (1). It is a thing. You may mix | blend the other additive mentioned later with this lubricating oil composition as needed.
The amount of the epoxy compound is preferably 1 to 30% by weight, more preferably 5 to 25% by weight, and particularly preferably 10 to 20% by weight. If it is less than 1% by weight, a sufficient anti-wear effect cannot be obtained, and even if it exceeds 30% by weight, it is difficult to improve the performance corresponding to the amount added.

  In addition, from the viewpoint of storage stability of the lubricating oil composition for metal working, the epoxy compound and the base oil are homogeneous during storage (such as the epoxy compound is dissolved in the base oil or the epoxy compound is dispersed in the base oil). Thus, it is preferable that both components are not separated into layers).

[Base oil]
The base oil according to the present invention is at least one selected from the group consisting of mineral oil, animal and vegetable oils and synthetic oils, and these base oils can be used alone or in combination of two or more.

As the mineral oil, a mineral oil generally used as a base oil in the field of lubricating oil can be used. As mineral oil, for example, a lubricating oil fraction obtained by further distilling atmospheric residue obtained by atmospheric distillation of crude oil is subjected to solvent removal, solvent extraction, hydrocracking, solvent dewaxing, hydrogenation. Examples include base oils manufactured by isomerizing waxes (gas-to-liquid waxes) that have been refined by performing one or more treatments such as refining, or mineral oil-based waxes or Fischer-Tropsch processes. . The mineral oil used in the present invention preferably has a kinematic viscosity at 100 ° C. in the range of 1.5 to 40 mm ² / s.

  Examples of animal and vegetable oils include beef tallow, lard, palm oil, coconut oil, rapeseed oil, castor oil, and the like.

  Synthetic oils include synthetic hydrocarbon oils such as poly-α-olefin, polybutene, alkylbenzene, and alkylnaphthalene, and isomerized oils of synthetic hydrocarbons obtained by the Fischer-Tropsch method, as well as organic acid esters and polyethers. It is done.

Examples of the poly-α-olefin include α-olefins having 2 to 16 carbon atoms (for example, ethylene, propylene, 1-butene, 1-hexene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene). Etc.), and a compound having a kinematic viscosity at 100 ° C. of 1.5 to 40 mm ² / s and a viscosity index of 100 or more is preferable, and a kinematic viscosity at 100 ° C. of 3 to 30 mm ² / It is more preferable that the viscosity index is 120 or more.

Examples of polybutene include a polymer of isobutylene and a copolymer of isobutylene and normal butylene, and those having a kinematic viscosity at 100 ° C. in the range of ² to 6000 mm ² / s are generally preferred.

  Examples of the alkyl benzene include monoalkyl benzene, dialkyl benzene, trialkyl benzene, and tetraalkyl benzene having a molecular weight of 200 to 450, which are substituted with a linear or branched alkyl group having 1 to 40 carbon atoms.

  Examples of the alkylnaphthalene include monoalkylnaphthalene and dialkylnaphthalene substituted with a linear or branched alkyl group having 1 to 30 carbon atoms.

  Examples of the organic acid ester include linear or branched saturated or unsaturated fatty acids having 10 to 22 carbon atoms such as palmitic acid, stearic acid, and oleic acid, and linear or branched chains having 3 to 22 carbon atoms. Monoesters with saturated or unsaturated aliphatic alcohols; linear C6-C22 aliphatic dicarboxylic acids such as adipic acid, azelaic acid, sebacic acid, dodecane-2 acid, etc. Or diesters with branched chain saturated or unsaturated aliphatic alcohols; aromatic polycarboxylic acids such as phthalic acid, isophthalic acid, terephthalic acid, trimellitic acid, pyromellitic acid, or their acid anhydrides and carbon A full ester with a linear or branched saturated or unsaturated aliphatic alcohol having 3 to 22; cyclohexanedicarboxylic acid or acid anhydride thereof Diester of C3-C22 linear or branched saturated or unsaturated aliphatic alcohol; Dimer acid and C3-C22 linear or branched saturated or unsaturated aliphatic Alicyclic polycarboxylic acid esters such as esters with alcohols; and polyols such as neopentyl glycol, trimethylolpropane, pentaerythritol, and linear or branched, saturated or unsaturated fatty acids having 3 to 22 carbon atoms And full esters or partial esters.

Examples of the polyether include polyethylene glycol, polypropylene glycol, oxyethylene-oxypropylene copolymer, polyester ether, polyphenyl ether, and the like, generally having a kinematic viscosity at 100 ° C. in the range of ² to 4000 mm ² / s. It is done.

  Among the above base oils, it is preferable to use a mineral oil as the base oil from the viewpoint of easy availability and function as a lubricating oil.

[Epoxy compound]
The epoxy compound according to the present invention has the following general formula (1)
[Wherein, R ¹ represents a substituent selected from the following group A, and R ² represents a substituent selected from the following group A or group B.
A: Saturated aliphatic hydrocarbon group having an epoxy group having 16 to 22 carbon atoms B: Saturated aliphatic hydrocarbon group having 16 to 22 carbon atoms]
It is a compound represented by these.
The number of epoxy groups in the saturated aliphatic hydrocarbon group of Group A is 1 or more, preferably 1 to 3.

  The epoxy compound can be obtained by a method of epoxidizing tetrahydrophthalate obtained by esterifying a tetrahydrophthalic anhydride and an alcohol compound in the presence of a peroxide.

In the above general formula (1), when R ² tries to obtain an epoxy compound selected from Group A, an unsaturated alcohol having 16 to 22 carbon atoms is used as an alcohol compound during the production. The number of double bonds in the unsaturated alcohol is 1 or more, preferably 1 to 3.

In the above general formula (1), when R ² tries to obtain an epoxy compound selected from Group B, an unsaturated alcohol having 16 to 22 carbon atoms and a saturated alcohol are used in combination as an alcohol compound during the production. The number of double bonds in the unsaturated alcohol is 1 or more, preferably 1 to 3.

  The acid value of the epoxy compound produced by the above production method is usually 2 mgKOH / g or less, and preferably 1 mgKOH / g or less. When the acid value is higher than 2 mgKOH / g, there is a concern about hydrolysis due to its own acid value.

As the above epoxy compound,
9-cetyl, 10-epoxycetyl-4,5-epoxyhexahydrophthalate, 9-stearyl, 10-epoxycetyl-4,5-epoxyhexahydrophthalate, 9-aralkyl, 10-epoxycetyl-4,5-epoxy Hexahydrophthalate, 9-behenyl, 10-epoxycetyl-4,5-epoxyhexahydrophthalate, 9-cetyl, 10-epoxystearyl-4,5-epoxyhexahydrophthalate, 9-stearyl, 10-epoxystearyl-4 , 5-epoxyhexahydrophthalate, 9-aralkyl, 10-epoxystearyl-4,5-epoxyhexahydrophthalate, 9-behenyl, 10-epoxystearyl-4,5-epoxyhexahydrophthalate, 9-cetyl, 10- Epoxy Arakil-4,5 Epoxy hexahydrophthalate, 9-stearyl, 10-epoxy aralkyl-4,5-epoxy hexahydrophthalate, 9-aralkyl, 10-epoxy aralkyl-4,5-epoxy hexahydrophthalate, 9-behenyl, 10-epoxy Aralkyl-4,5-epoxyhexahydrophthalate, 9-cetyl, 10-epoxybehenyl-4,5-epoxyhexahydrophthalate, 9-stearyl, 10-epoxybehenyl-4,5-epoxyhexahydrophthalate, 9- Aralkyl, 10-epoxybehenyl-4,5-epoxyhexahydrophthalate, 9-behenyl, 10-epoxybehenyl-4,5-epoxyhexahydrophthalate, di (9,10-epoxycetyl) -4,5-epoxyhexa Hydrophthalate, di (9,10 Epoxystearyl) -4,5-epoxyhexahydrophthalate, di (9,10-epoxyaralkyl) -4,5-epoxyhexahydrophthalate, di (9,10-epoxybehenyl) -4,5-epoxyhexahydro Phthalate is exemplified.

[Other additives]
In order to improve the performance of the lubricating oil composition for metal working according to the present invention, one or more conventionally known various additives can be appropriately added within a range not impairing the effects of the present invention. It is. Examples of such additives include ashless dispersants, metal detergents, pour point depressants, rust inhibitors, and antifoaming agents. Moreover, you may add an antiwear agent, extreme pressure agent, an oiliness agent, a friction modifier, antioxidant, a corrosion inhibitor, etc. as needed. Usually, the addition amount (weight% of the additive with respect to the total amount of base oil and an epoxy compound) applied preferably is shown with the specific example of said each additive.

  Examples of ashless dispersants include polyalkenyl succinimides, polyalkenyl succinic amides, polyalkenyl benzylamines, polyalkenyl succinic acid esters, and derivatives obtained by treating these with boron compounds. 2 to 10 weight% is mentioned.

  Examples of metal detergents include metal sulfonates, overbased metal sulfonates, metal phenates, overbased metal phenates, metal phosphonates, salicylates, carboxylates, etc., and the addition amount is 2 to 10% by weight. .

  Examples of the pour point depressant include polyalkyl methacrylate, polyalkyl acrylate, condensate of chlorinated paraffin and naphthalene, condensate of chlorinated paraffin and phenol, polybutene, polyalkyl styrene, polyvinyl acetate and the like. Is 0.1 to 1% by weight.

  Examples of the rust preventive include sulfonate-based, carboxylic acid-based, organic amine soap-based, and sorbitan partial ester-based compounds, and the amount added is 0.05 to 3% by weight.

Examples of the antifoaming agent include silicone-based compounds such as polydimethylsilicone, and the amount added is 1 to 100 ppm.

  Antiwear / extreme pressure agents include organic sulfurs such as olefin polysulfides, sulfurized fats and oils, dialkyl polysulfides, chlorinated paraffins, organophosphorous compounds such as alkyl and aryl phosphites, alkyl and aryl phosphites, and dialkyldithiophosphorus. Zinc acid type, zinc dialkyldithiocarbamate type, and long chain fatty acid type compounds are exemplified, and the addition amount is 0.05 to 10% by weight.

  Examples of oiliness agents and friction modifiers include fatty acids such as stearic acid and oleic acid, alcohols such as stearyl alcohol and oleyl alcohol, amines such as oleylamine, and organic molybdenum such as molybdenum dithiocarbamate. As 0.1 to 5.0% by weight.

 Antioxidants include 2,6-di-t-butylparacresol, 4,4′-methylenebis (2,6-di-t-butylphenol), 4,4′-bis (2,6-di-t). -Butylphenol), 4,4'-bis (2-methyl-6-t-butylphenol), 2,2'-methylenebis (4-ethyl-6-t-butylphenol), 2,2'-methylenebis (4-methyl) Phenolic antioxidants such as -6-tert-butylphenol), 4,4'-butylidenebis (3-methyl-6-tert-butylphenol), 4,4'-thiobis (2-methyl-tert-butylphenol), N -Alkylated diphenylamines such as phenyl-α-naphthylamine, N-octylphenyl-α-naphthylamine, p, p'-dioctyldiphenylamine, paraphenylenedia Amine-based antioxidants such as min, phosphorus-based antioxidants such as di-t-butylphenyl phosphite, triphenylphosphorothionate, alkylated triphenylphosphorothionate, phenothiazine, sulfurized fats and oils, dibenzyl disulfide And sulfur-based antioxidants such as dicetyl sulfide.

  Examples of the corrosion inhibitor include thiadiazole compounds such as benzotriazole and 2,5-bis (n-dodecyldithio) -1,3,4-thiadiazole, and the addition amount thereof is 0.01 to 0.4. % By weight.

  Examples of the antifoaming agent include silicone-based compounds such as polydimethylsilicone, and the amount added is 1 to 100 ppm.

Hereinafter, the present invention will be described in detail with reference to examples, but the present invention is not limited to the examples. The performance was evaluated by the following method.

According to JPI-5S-32-90 (Japan Petroleum Institute: Wear resistance test method of lubricant (shell four-ball type)) except that the wear prevention performance test load was changed from the standard condition of 40 kgf to 30 kgf. Using a high-speed four-ball wear tester (manufactured by Shinko Engineering Co., Ltd.), the test was performed under the conditions of a rotational speed of 1200 rpm, a load of 30 kgf, and a time of 60 minutes, and the wear scar diameter was measured. The long and short diameters of the wear marks were measured, and the average value was calculated as the wear mark diameter. The smaller the wear scar, the better the lubricity.

50 mL of the base oil and the epoxy compound (base oil / epoxy compound = 80/20, 90/10) were put into a 100 mL flask equipped with a solubility test stirrer, and the mixture was sufficiently stirred and allowed to stand for 1 hour. After standing, it was visually observed to determine that the base oil and the epoxy compound were separated into “x”, and those that were not separated were judged as “◯”.

  The composition of each sample used for performance evaluation is shown in Tables 1 and 2. The components of each example and comparative example are as follows.

[Base oil]
Mineral oil: Paraffinic mineral oil (Cosmo Oil Lubricants Co., Ltd. “Cosmo Neutral 100”, kinematic viscosity at 100 ° C. 4.3 mm ² / s)

[Epoxy compound]
Epoxy A: Di (9,10-epoxystearyl) -4,5-epoxyhexahydrophthalate Epoxy B: Di (2-ethylhexyl) -4,5-epoxyhexahydrophthalate (trade name “Sanso Sizer E-PS Shin Nippon Rika)
Epoxy C: di (n-hexyl) -4,5-epoxyhexahydrophthalate, di (n-octyl) -4,5-epoxyhexahydrophthalate, di (n-decyl) -4,5-epoxyhexahydrophthalate Mixture (trade name “Sanso Sizer nE-PS”, manufactured by Shin Nippon Chemical Co., Ltd.)
Epoxy D: Mixture of n-dodecyl glycidyl ether and n-tetradecyl glycidyl ether (trade name “Rikaresin L-200, manufactured by Shin Nippon Rika”)
Epoxy E: 1,4-cyclohexanedimethanol glycidyl ether (trade name “Rica Resin DME-100”)
Epoxy F: glycidyl neodecanoate (trade name “Cardura E10P”, manufactured by Hexion Specialty Chemicals Japan)
Epoxy G: 3,4-epoxycyclohexenylmethyl-3 ′, 4′-epoxycyclohexene carboxylate (manufactured by Daicel Chemical Industries, Ltd.)
Epoxy H: Epoxidized soybean oil (trade name “Sansosizer E-2000H”, manufactured by Shin Nippon Rika)

Examples 1-2
Abrasion prevention performance test and solubility test were performed on sample oils having the compositions shown in Tables 1 and 2. The obtained results are shown in Tables 1 and 2.

Comparative Examples 1-14
Abrasion prevention performance test and solubility test were performed on sample oils having the compositions shown in Tables 1 and 2. The obtained results are also shown in Tables 1 and 2.

  The lubricating oil composition containing an epoxy compound having a specific structure of the present invention is useful as a metal working oil because it has excellent wear resistance and good solubility of the epoxy compound in the base oil.

Claims (4)

At least one base oil selected from the group consisting of mineral oil, animal and vegetable oils and synthetic oils, and general formula (1)
[Wherein, R ¹ represents a substituent selected from Group A below, and R ² represents a substituent selected from Group A or Group B below.
A: Saturated aliphatic hydrocarbon group having an epoxy group having 16 to 22 carbon atoms B: Saturated aliphatic hydrocarbon group having 16 to 22 carbon atoms]
A lubricating oil composition for metal working comprising at least one epoxy compound represented by the formula: The lubricating oil composition for metal working according to claim 1, wherein the content of the epoxy compound represented by the general formula (1) is 1 to 30% by weight . In the general formula (1), metalworking lubricating oil composition according to claim 1 or 2 R ¹ and R ² is a substituent selected from Group A. General formula (1)
[In the formula, R ¹ represents a substituent selected from the following Group A, R ² represents a substituent selected from the following Group A or B groups.
A: Saturated aliphatic hydrocarbon group having an epoxy group having 16 to 22 carbon atoms B: Saturated aliphatic hydrocarbon group having 16 to 22 carbon atoms]
A method for improving the anti-wear performance of a lubricating oil composition for metal working, which comprises containing at least one epoxy compound represented by the formula: