JP5945486B2 - Metalworking oil composition - Google Patents

Description

  The present invention relates to a metalworking oil composition. Specifically, it is preferable for metal processing such as rolling (including hot rolling and cold rolling), drawing, ironing, drawing, pressing, forging (including hot forging), and cutting / grinding. The present invention relates to a metal working oil composition to be used, and particularly to a metal working oil composition suitable for cold rolling.

  Lubricating oil base oils are often applied with the classification defined by the American Petroleum Institute (API). In this classification, the sulfur content, saturation content, and viscosity index in the base oil are used as parameters, and the mineral oil base oil is classified into groups 1 to 5. Among these, the Group 3 base oil is a high-viscosity index base oil highly refined by hydrocracking, and the Group 4 base oil is a poly α-olefin having a high viscosity index, and has an engine with low fuel consumption. It is indispensable for oil. The viscosity index of Group 3 and 4 base oils is 120 or more, and a high viscosity index means that the kinematic viscosity of the lubricating oil hardly changes even if the temperature at which the lubricating oil is used changes. Lubricating oils, including engine oils, are designed to perform well under the harshest conditions in the machinery and equipment. In terms of engine oil, the engine oil is designed so as not to cause problems under high temperature conditions when traveling at high speed. However, in a relatively gentle state where the vehicle travels at a low speed, the viscosity becomes too high, and the resistance increases to deteriorate the fuel consumption. The high viscosity index base oil has an excellent fuel saving effect because the viscosity at low speed does not become too high even if the viscosity is adjusted so as to exhibit good characteristics under severe conditions of high speed.

  The same applies to metalworking oils, and it is considered to be most important to ensure a viscosity that does not cause problems under conditions where the processing speed is high and the calorific value is large. On the other hand, when the viscosity is excessively increased, the viscosity resistance is increased and the workability is deteriorated. Therefore, a base oil having a high viscosity index such as a group 3 base oil is demanded and widely used. In addition, group 3 base oils usually have a merit that the sulfur content is low, so the odor is low, and the metal working performed in an open state provides a good working environment.

JP 2008-013682 A

  However, according to the knowledge of the present inventors, a new problem arises in the field of metalworking oil due to the widespread use of Group 3 base oils. That is, metal processing is performed using various materials under various conditions, but surface damage is likely to occur when using a relatively hard material such as stainless steel, copper, titanium, or nickel. This surface damage is particularly conspicuous under the condition that the processing speed is conventionally considered to be low load.

  Here, the oil film thickness of the lubricated portion is generally proportional to the product of the viscosity of the lubricating oil and the processing speed, and inversely proportional to the load. As the processing speed decreases, the friction decreases and the temperature decreases, so the oil film appears to be thicker. However, if the effect of lowering the speed is greater, the oil film becomes thinner. In addition, since the friction coefficient increases as the oil film becomes thinner, a further load for processing is required, and as a result, the oil film may become thinner. As a result, there is a problem of surface damage of the workpiece under a low speed condition that has been regarded as safe in the past.

  Therefore, the present inventors have studied to solve the above problems. As a result, it can be seen that there is a range of viscosity index that is unlikely to cause problems under any conditions from high speed to low speed, and there is also an appropriate sulfur content that can improve processability without affecting the odor of the oil. I understood that. Furthermore, it has also been found that the use of a combination of a base oil having a viscosity index and a sulfur content within a specific range and a specific additive improves the effect of preventing surface damage.

  The present invention was made from the above viewpoint, and has a metal working oil composition that has good lubricity from a high processing speed to a low processing speed and can sufficiently prevent surface damage of a workpiece. It is intended to provide.

  In order to solve the above problems, the present invention provides at least a base oil which is a mineral oil having a viscosity index of 70 or more and 115 or less and a sulfur content of 100 mass ppm or more and 2000 mass ppm or less, an ester, an alcohol, and a phosphorus compound. And a metalworking oil composition containing the same.

  The metalworking oil composition of the present invention is preferably used for metalworking of a workpiece containing at least one selected from stainless steel, copper, titanium, nickel, and alloys based on these. In particular, the metal working oil composition of the present invention is suitable when the metal working is plastic working or cold rolling.

  ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to provide the metal processing oil which has favorable lubricity from the conditions with a high processing speed to the low conditions, and can fully prevent the surface damage of a workpiece.

  Hereinafter, preferred embodiments of the present invention will be described in detail.

  The metalworking oil composition according to an embodiment of the present invention is selected from a base oil that is a mineral oil having a viscosity index of 70 to 115 and a sulfur content of 100 mass ppm to 2000 mass ppm, an ester, an alcohol, and a phosphorus compound. And at least one kind.

  As mineral oil, lubricating oil fraction obtained by atmospheric distillation and vacuum distillation of crude oil is subjected to solvent removal, solvent extraction, hydrocracking, solvent dewaxing, catalytic dewaxing, hydrorefining, sulfuric acid washing Among paraffinic or naphthenic mineral oils obtained by appropriately combining one or more purification means such as white clay treatment, those having a viscosity index and a sulfur content within the above ranges can be mentioned. .

  The viscosity index of mineral oil is 70 or more, preferably 75 or more, more preferably 80 or more, and still more preferably 85. The viscosity index of mineral oil is 115 or less, preferably 113 or less, more preferably 110 or less, and still more preferably 108 or less. When the viscosity index is less than the above lower limit, the oil film becomes thicker than the optimum value in processing at low speed, which causes an increase in load. In the case of rolling, the surface gloss of the processed material decreases due to an increase in oil pits. On the other hand, when the viscosity index exceeds the above upper limit, the formation of an oil film becomes insufficient in processing at low speed, and problems such as seizure occur. In addition, the viscosity index as used in the field of this invention means the viscosity index measured based on JISK2283-1993.

  The sulfur content of the mineral oil is 100 ppm or more, preferably 200 ppm or more, more preferably 300 ppm or more, still more preferably 350 ppm or more, based on the total amount of mineral oil. Further, the sulfur content of the mineral oil is 2000 ppm or less, preferably 1700 ppm or less, more preferably 1200 ppm or less, and further preferably 1000 ppm or less, based on the total amount of mineral oil. If the sulfur content is too small, the effect of improving the workability will be insufficient, and if it is too much, the odor may cause a problem in workability.

The viscosity of the mineral oil is not particularly limited, the kinematic viscosity at 40 ° C., preferably at least 2 mm ² / s, more preferably at least 3 mm ² / s, even more preferably at least 4 mm ² / s, is more than 5 mm ² / s Most preferred. Further, the kinematic viscosity at 40 ° C., preferably not more than 50 mm ² / s, more preferably not more than 30 mm ² / s, even more preferably 20 mm ² / s or less, most preferably 10 mm ² / s.

  The paraffin content of the mineral oil is not particularly limited, but is preferably 20% by mass or more, more preferably 30% by mass or more, and further preferably 35% by mass or more based on the total amount of mineral oil. The naphthene content is not particularly limited, but is preferably 10% by mass or more, more preferably 15% by mass or more, and further preferably 20% by mass or more based on the total amount of mineral oil. The naphthene content is preferably 80% by mass or less, more preferably 70% by mass or less, and still more preferably 65% by mass or less, based on the total amount of mineral oil. The aromatic content is not particularly limited, but is preferably 25% by mass or less, more preferably 20% by mass or less, and further preferably 15% by mass or less, based on the total amount of mineral oil.

  The base oil in the metalworking oil composition according to the present embodiment may be composed only of the above mineral oil, but it is possible to use fats and oils, synthetic oils, or two or more of these in combination with the mineral oil. it can.

  Examples of fats and oils include beef tallow, lard, soybean oil, rapeseed oil, rice bran oil, coconut oil, palm oil, palm kernel oil, and hydrogenated products thereof.

  Synthetic oils include, for example, poly α-olefins (ethylene-propylene copolymer, polybutene, 1-octene oligomer, 1-decene oligomer, and hydrides thereof), alkylbenzene, alkylnaphthalene, monoester (butyl stearate). Octyl laurate), diester (ditridecyl glutarate, di-2-ethylhexyl adipate, diisodecyl adipate, ditridecyl adipate, di-2-ethylhexyl sepacate, etc.), polyester (trimellitic acid ester, etc.), polyol ester (tri Methylolpropane caprylate, trimethylolpropane pelargonate, pentaerythritol-2-ethylhexanoate, pentaerythritol pelargonate), polyoxyalkylene Call, polyphenyl ether, dialkyl diphenyl ether, (such as tricresyl phosphate) phosphoric acid ester, fluorine-containing compound (perfluoropolyether, such as fluorinated polyolefins) and and the like silicone oils.

  The metalworking oil composition according to this embodiment contains at least one selected from esters, alcohols and phosphorus extreme pressure agents in addition to the above base oil. These have a function as a lubricity improver. In addition, when using ester or phosphate ester as a base oil and a lubricity improver, respectively, different types of base oil and lubricity improver are used. Esters and phosphorus compounds that are preferred as lubricating oil improvers will be described later.

  The alcohol constituting the ester as the lubricity improver may be a monohydric alcohol or a polyhydric alcohol. The carboxylic acid constituting the ester may be a monobasic acid or a polybasic acid.

  As the monohydric alcohol, one having 1 to 24 carbon atoms is usually used, and such an alcohol may be linear or branched. Specific examples of the alcohol having 1 to 24 carbon atoms include methanol, ethanol, linear or branched propanol, linear or branched butanol, linear or branched octanol, and linear Or branched nonanol, linear or branched decanol, linear or branched undecanol, linear or branched dodecanol, linear or branched tridecanol, linear or branched tetra Decanol, linear or branched pentadecanol, linear or branched hexadecanol, linear or branched heptadecanol, linear or branched octadecanol, linear Or branched nonadecanol, linear or branched eicosanol, linear or branched heneicosanol, linear or branched tricosanol, linear or branched Tetracosanol, and mixtures thereof of.

  Moreover, as a polyhydric alcohol, the thing of 2-10 valence is preferable, Preferably it is 2-6 valence. Specific examples of the 2 to 10 valent polyhydric alcohol include, for example, ethylene glycol, diethylene glycol, polyethylene glycol (3 to 15 mer of ethylene glycol), propylene glycol, dipropylene glycol, and polypropylene glycol (3 to 15 of propylene glycol). Monomer), 1,3-propanediol, 1,2-propanediol, 1,3-butanediol, 1,4-butanediol, 2-methyl-1,2-propanediol, 2-methyl-1,3 -Dihydric alcohols such as propanediol, 1,2-pentanediol, 1,3-pentanediol, 1,4-pentanediol, 1,5-pentanediol, neopentylglycol; glycerin, polyglycerin (glycerin 2- Octamers such as diglycerin, triglyceride Phosphorus, tetraglycerin), trimethylolalkanes (trimethylolethane, trimethylolpropane, trimethylolbutane, etc.) and their 2- to 8-mer, pentaerythritol and their 2- to 4-mer, 1,2,4-butane Triol, 1,3,5-pentanetriol, 1,2,6-hexanetriol, 1,2,3,4-butanetetrol, sorbitol, sorbitan, sorbitol glycerin condensate, adonitol, arabitol, xylitol, mannitol, etc. Polyhydric alcohols; sugars such as xylose, arabinose, ribose, rhamnose, glucose, fructose, galactose, mannose, sorbose, cellobiose, maltose, isomaltose, trehalose, sucrose, and mixtures thereof It is.

  Among these, ethylene glycol, diethylene glycol, polyethylene glycol (ethylene glycol 3-10 mer), propylene glycol, dipropylene glycol, polypropylene glycol (propylene glycol 3-10 mer), 1,3-propanediol, 2-methyl-1,2-propanediol, 2-methyl-1,3-propanediol, neopentyl glycol, glycerin, diglycerin, triglycerin, trimethylolalkane (trimethylolethane, trimethylolpropane, trimethylolbutane, etc. ) And dimers and tetramers thereof, pentaerythritol, dipentaerythritol, 1,2,4-butanetriol, 1,3,5-pentanetriol, 1,2,6-hexanetriol, 1,2 3,4 butane tetrol, sorbitol, sorbitan, sorbitol glycerin condensate, adonitol, arabitol, xylitol, divalent to hexavalent polyhydric alcohols, and mixtures thereof such as mannitol and the like are more preferable. More preferred are ethylene glycol, propylene glycol, neopentyl glycol, glycerin, trimethylol ethane, trimethylol propane, pentaerythritol, sorbitan, and mixtures thereof.

  The monobasic acid constituting the ester as the lubricity improver is usually a fatty acid having 6 to 24 carbon atoms, which may be linear or branched, and may be saturated or unsaturated. . Specifically, for example, linear or branched hexanoic acid, linear or branched octanoic acid, linear or branched nonanoic acid, linear or branched decanoic acid, linear or Branched undecanoic acid, linear or branched dodecanoic acid, linear or branched tridecanoic acid, linear or branched tetradecanoic acid, linear or branched pentadecanoic acid, linear or Branched hexadecanoic acid, linear or branched octadecanoic acid, linear or branched hydroxyoctadecanoic acid, linear or branched nonadecanoic acid, linear or branched eicosanoic acid, linear Or a saturated fatty acid such as branched heneicosanoic acid, linear or branched docosanoic acid, linear or branched tricosanoic acid, linear or branched tetracosanoic acid; linear or branched hexenoic acid , Linear or branched Heptenoic acid, linear or branched octenoic acid, linear or branched nonenic acid, linear or branched decenoic acid, linear or branched undecenoic acid, linear or branched Dodecenoic acid, linear or branched tridecenoic acid, linear or branched tetradecenoic acid, linear or branched pentadecenoic acid, linear or branched hexadecenoic acid, linear or branched Octadecenoic acid, linear or branched hydroxyoctadecenoic acid, linear or branched nonadecenoic acid, linear or branched eicosenoic acid, linear or branched heneicosenoic acid, linear or branched Docosenoic acid, linear or branched tricosenoic acid, unsaturated fatty acids such as linear or branched tetracosenoic acid, and mixtures thereof. Of these, saturated fatty acids having 8 to 20 carbon atoms, unsaturated fatty acids having 8 to 20 carbon atoms, and mixtures thereof are particularly preferable.

  Examples of the polybasic acid constituting the ester as the lubricity improver include dibasic acids having 2 to 16 carbon atoms and trimellitic acid. The dibasic acid having 2 to 16 carbon atoms may be linear or branched, and may be saturated or unsaturated. Specifically, for example, ethanedioic acid, propanedioic acid, linear or branched butanedioic acid, linear or branched pentanedioic acid, linear or branched hexanedioic acid, linear Or branched octanedioic acid, linear or branched nonanedioic acid, linear or branched decanedioic acid, linear or branched undecanedioic acid, linear or branched dodecanedioic acid Acid, linear or branched tridecanedioic acid, linear or branched tetradecanedioic acid, linear or branched heptadecanedioic acid, linear or branched hexadecanedioic acid; linear or Branched hexenedioic acid, linear or branched octenedioic acid, linear or branched nonenedioic acid, linear or branched decenedioic acid, linear or branched undecenedioic acid , Linear or branched dodecenedioic acid, linear or branched tridecenedioic acid, linear Or branched tetradecene diacid, linear or branched heptadecenoic acid, straight-chain or branched hexadecene diacid; include and mixtures thereof.

In this embodiment, ester by the combination of arbitrary alcohol and carboxylic acid can be used, and it does not specifically limit. Specifically, esters shown in the following (i) to (vii) can be preferably used.
(I) ester of monohydric alcohol and monobasic acid (ii) ester of polyhydric alcohol and monobasic acid (iii) ester of monohydric alcohol and polybasic acid (iv) polyhydric alcohol and polybasic acid (V) Esters of monohydric alcohols and mixed alcohols of polyhydric alcohols with polybasic acids (vi) Esters of polyhydric alcohols with monobasic acids and mixed carboxylic acids of polybasic acids (vii) Monohydric alcohols and Ester of mixed alcohol of polyhydric alcohol and mixed carboxylic acid of monobasic acid and polybasic acid.

  When a polyhydric alcohol is used as the alcohol component, the ester may be a complete ester in which all of the hydroxyl groups in the polyhydric alcohol are esterified. It may be a partial ester remaining as it is. In addition, when a polybasic acid is used as the carboxylic acid component, the ester may be a complete ester in which all carboxyl groups in the polybasic acid are esterified. May be a partial ester remaining.

  As the ester as the lubricity improver, any of the above-mentioned ones can be used. Among these, (i) an ester of a monohydric alcohol and a monobasic acid, and (iii) An ester of a monohydric alcohol and a polybasic acid is preferred, (i) an ester of a monohydric alcohol and a monobasic acid is more preferred, (i) an ester of a monohydric alcohol and a monobasic acid, and (iii) a monohydric alcohol It is most preferable to use an ester of polybasic acid in combination.

  (I) The total carbon number of the ester of monohydric alcohol and monobasic acid that is preferably used in this embodiment is not particularly limited, but an ester having a total carbon number lower limit of 7 or more is preferable, and an ester of 9 or more Are more preferred, with 11 or more esters being most preferred. Further, an ester having an upper limit of the total carbon number of 28 or less is preferred, an ester of 26 or less is more preferred, and an ester of 24 or less is most preferred. Although there is no restriction | limiting in particular in carbon number of the said monohydric alcohol, C1-C10 is preferable, C1-C8 is more preferable, C1-C6 is still more preferable, C1-C4 is the most preferable. . Although there is no restriction | limiting in particular in carbon number of the said monobasic acid, C6-C22 is preferable, C8-C20 is more preferable, C10-C18 is the most preferable. If the total carbon number, the carbon number of the alcohol and the carbon number of the monobasic acid each exceed the upper limit, the possibility of increasing the occurrence of stain and corrosion increases, and the fluidity is lost in winter. There is a tendency that the risk of becoming difficult becomes greater, or that the solubility in the lubricating base oil decreases and the risk of precipitation increases. Further, when the total carbon number, the carbon number of the alcohol, and the carbon number of the monobasic acid are each lower than the lower limit value, the lubricity tends to be insufficient, and the working environment is deteriorated by odor. There is a fear.

The form of the ester of (iii) monohydric alcohol and polybasic acid preferably used in this embodiment is not particularly limited, but may be a diester represented by the following general formula (1) or an ester of trimellitic acid. preferable.
R ¹ —O—CO— (CH ₂ ) _n —CO—O—R ² (1)
[Wherein, R ¹ and R ² may be the same or different and each represents a hydrocarbon group, and n represents an integer of 4 to 8. ]

R ¹ and R ² in the general formula (1) each represent a hydrocarbon group, and the hydrocarbon group preferably has 3 to 10 carbon atoms. If the hydrocarbon group has less than 3 carbon atoms, the lubricity improvement effect may not be expected, and the working environment may deteriorate due to odor. In addition, if the hydrocarbon group has more than 10 carbon atoms, there is a greater risk of increasing the occurrence of stains and corrosion, and there is a greater risk of losing fluidity and difficulty in handling in winter. There is a tendency that the risk of precipitation decreases and the possibility of precipitation increases.

Examples of the hydrocarbon group represented by R ¹ and R ² in the general formula (1) include an alkyl group, an alkenyl group, an alkylcycloalkyl group, an alkylphenyl group, and a phenylalkyl group, and an alkyl group is particularly preferable.

When R ¹ and R ² are alkyl groups, the alkyl group may be either a linear alkyl group or a branched alkyl group, and a linear alkyl group and a branched alkyl group are mixed in the same molecule. A branched alkyl group is preferred.

Specific examples of the alkyl group represented by R ¹ and R ² include a linear or branched propyl group, a linear or branched butyl group, a linear or branched pentyl group, and a linear or branched hexyl group. A linear or branched heptyl group, a linear or branched octyl group, a linear or branched nonyl group, a linear or branched decyl group, and the like.

  Moreover, n in General formula (1) shows the integer of 4-8. In addition, when n exceeds 8, the possibility of increasing the occurrence of stains and corrosion increases, the possibility of losing fluidity and difficulty in handling in winter increases, and the solubility in lubricating base oil decreases. There is a tendency that the risk of precipitation increases. Moreover, when n is less than 4, there is a possibility that the improvement effect of lubricity may not be expected, and the working environment tends to deteriorate due to odor. Furthermore, a diester in which n is 4 or 6 is particularly preferable from the viewpoint of availability of raw materials and price.

  The diester represented by the general formula (1) can be obtained by an arbitrary method. For example, the diester represented directly by a carbonic acid number of 6 to 10 (adipic acid, pimelic acid, corkic acid, azelaic acid, sebacic acid in order from the carbon number of 6). Examples thereof include a method of esterifying a chain saturated dicarboxylic acid or a derivative thereof and an alcohol having 3 to 10 carbon atoms.

  Moreover, when ester is ester of trimellitic acid and monohydric alcohol, although carbon number of the said monohydric alcohol does not have a restriction | limiting in particular, C1-C10 is preferable, C1-C8 is more preferable, Carbon Numbers 1 to 6 are more preferable, and carbon numbers 1 to 4 are most preferable. When the number of carbon atoms of the monohydric alcohol exceeds 10, the possibility of increasing the occurrence of stains and corrosion increases, and the possibility of losing fluidity and difficulty in handling in winter increases. There is a tendency that the risk of precipitation decreases and the possibility of precipitation increases. The ester of trimellitic acid may be a partial ester (monoester or diester) or a complete ester (triester).

  Particularly preferred examples of esters used as lubricity improvers include, specifically, methyl laurate, butyl laurate, methyl stearate, butyl stearate, methyl oleate, butyl oleate, and adipic acid and carbon number. Examples include diesters with 4 to 10 alcohols.

  Examples of the alcohol used as the lubricity improver include monohydric alcohols and polyhydric alcohols exemplified in the description of the ester. Among them, monohydric alcohols and dihydric alcohols are preferable, and monohydric alcohols are used alone. It is more preferable to use a monohydric alcohol and a dihydric alcohol in combination. Moreover, as a bihydric alcohol, what has an ether bond in a molecule | numerator is preferable.

  The number of carbon atoms of the monohydric alcohol and dihydric alcohol is preferably 6 or more, more preferably 7 or more, still more preferably 8 or more, and particularly preferably 9 or more. In addition, when carbon number of monohydric alcohol and dihydric alcohol is less than 6, there exists a tendency for lubricity to become inadequate and there exists a possibility that a working environment may deteriorate with an odor. Moreover, carbon number of monohydric alcohol and dihydric alcohol becomes like this. Preferably it is 20 or less, More preferably, it is 18 or less. The alcohol may be linear or branched and may be saturated or unsaturated. When the number of carbons of monohydric alcohol and dihydric alcohol exceeds 20, the possibility of increasing the occurrence of stains and corrosion increases, and the possibility of losing fluidity and difficulty in handling in winter increases. There is a tendency that the solubility in oil decreases and the risk of precipitation increases.

  Particularly preferred examples of alcohols used as lubricity improvers include lauryl alcohol, myristyl alcohol, palmityl alcohol, oleyl alcohol, branched and saturated C12 to C16 alcohols. Examples include ethylene glycol 5-9 mer, propylene glycol 2-6 mer, and mixtures of two or more thereof.

  The content of the ester and alcohol as a lubricity improver is preferably 2 to 50% by mass based on the total amount of the composition. That is, the content is preferably 3% by mass or more, more preferably 5% by mass or more, from the viewpoint of an improvement in lubricity. In addition, the content is preferably 45% by mass or less, more preferably 40% by mass or less from the viewpoint that if the content is too large, the occurrence of stain or corrosion may increase.

  Specific examples of the phosphorus compound used as the lubricity improver include, for example, phosphoric acid esters, acidic phosphoric acid esters, amine salts of acidic phosphoric acid esters, chlorinated phosphoric acid esters, phosphorous acid esters, and phosphors. Examples include thionate and metal salts of phosphorus compounds represented by the following general formula (2) or (3). Examples of these phosphorus compounds include esters of phosphoric acid, phosphorous acid or thiophosphoric acid and alkanols, polyether type alcohols, or derivatives thereof.

［式（２）中、Ｘ^１、Ｘ^２及びＸ^３は同一でも異なっていてもよく、それぞれ酸素原子又は硫黄原子を表し、Ｘ^１、Ｘ^２又はＸ^３の少なくとも２つは酸素原子であり、Ｒ^３、Ｒ^４、及びＲ^５は同一でも異なっていてもよく、それぞれ水素原子又は炭素数１〜３０の炭化水素基を表す。］

[In Formula (2), X ¹ , X ² and X ³ may be the same or different and each represents an oxygen atom or a sulfur atom, and at least two of X ¹ , X ² or X ³ are oxygen atoms. , R ³ , R ⁴ , and R ⁵ may be the same or different and each represents a hydrogen atom or a hydrocarbon group having 1 to 30 carbon atoms. ]

［式（２）中、Ｘ^４、Ｘ^５、Ｘ^６及びＸ^７は同一でも異なっていてもよく、それぞれ酸素原子又は硫黄原子を表し、Ｘ^４、Ｘ^５、Ｘ^６又はＸ^７の少なくとも３つは酸素原子であり、Ｒ^６、Ｒ^７及びＲ^８は同一でも異なっていてもよく、それぞれ水素原子又は炭素数１〜３０の炭化水素基を表す。］

[In Formula (2), X ⁴ , X ⁵ , X ⁶ and X ⁷ may be the same or different and each represents an oxygen atom or a sulfur atom, and at least 3 of X ⁴ , X ⁵ , X ⁶ or X ⁷ One is an oxygen atom, and R ⁶ , R ⁷ and R ⁸ may be the same or different and each represents a hydrogen atom or a hydrocarbon group having 1 to 30 carbon atoms. ]

More specifically, the phosphate ester includes tributyl phosphate, tripentyl phosphate, trihexyl phosphate, triheptyl phosphate, trioctyl phosphate, trinonyl phosphate, tridecyl phosphate, triundecyl phosphate, tridodecyl phosphate, tritridecyl Phosphate, tritetradecyl phosphate, tripentadecyl phosphate, trihexadecyl phosphate, triheptadecyl phosphate, trioctadecyl phosphate, trioleyl phosphate, triphenyl phosphate, tricresyl phosphate, trixylenyl phosphate, cresyl diphenyl phosphate, xyl Renyl diphenyl phosphate and the like;
Examples of acidic phosphate esters include monobutyl acid phosphate, monopentyl acid phosphate, monohexyl acid phosphate, monoheptyl acid phosphate, monooctyl acid phosphate, monononyl acid phosphate, monodecyl acid phosphate, monoundecyl acid phosphate, monododecyl Acid phosphate, monotridecyl acid phosphate, monotetradecyl acid phosphate, monopentadecyl acid phosphate, monohexadecyl acid phosphate, monoheptadecyl acid phosphate, monooctadecyl acid phosphate, monooleyl acid phosphate, dibutyl acid phosphate, dipentyl acid , Dihexyl reed Dophosphate, diheptyl acid phosphate, dioctyl acid phosphate, dinonyl acid phosphate, didecyl acid phosphate, diundecyl acid phosphate, didodecyl acid phosphate, ditridecyl acid phosphate, ditetradecyl acid phosphate, dipentadecyl acid, dipentadecyl acid Hexadecyl acid phosphate, diheptadecyl acid phosphate, dioctadecyl acid phosphate, dioleyl acid phosphate, etc .;
Examples of the amine salt of acidic phosphate ester include methylamine, ethylamine, propylamine, butylamine, pentylamine, hexylamine, heptylamine, octylamine, dimethylamine, diethylamine, dipropylamine, dibutylamine, Salts with amines such as dipentylamine, dihexylamine, diheptylamine, dioctylamine, trimethylamine, triethylamine, tripropylamine, tributylamine, tripentylamine, trihexylamine, triheptylamine, trioctylamine, etc .;
Examples of the chlorinated phosphate ester include tris-dichloropropyl phosphate, tris-chloroethyl phosphate, tris-chlorophenyl phosphate, polyoxyalkylene bis [di (chloroalkyl)] phosphate, and the like;
As phosphites, dibutyl phosphite, dipentyl phosphite, dihexyl phosphite, diheptyl phosphite, dioctyl phosphite, dinonyl phosphite, didecyl phosphite, diundecyl phosphite, didodecyl phosphite, dioleyl Phosphite, diphenyl phosphite, dicresyl phosphite, tributyl phosphite, tripentyl phosphite, trihexyl phosphite, triheptyl phosphite, trioctyl phosphite, trinonyl phosphite, tridecyl phosphite, triundecyl phosphite Phyto, tridodecyl phosphite, trioleyl phosphite, triphenyl phosphite, tricresyl phosphite etc .;
The phosphorothioates include tributyl phosphorothioate, tripentyl phosphorothioate, trihexyl phosphorothionate, triheptyl phosphorothionate, trioctyl phosphorothionate, trinonyl phosphorothionate, tridecyl Phosphorothioate, triundecyl phosphorothionate, tridodecyl phosphorothioate, tritridecyl phosphorothioate, tritetradecyl phosphorothioate, tripentadecyl phosphorothionate, trihexadecyl phosphorothionate , Triheptadecyl phosphorothioate, trioctadecyl phosphorothioate, trioleyl phosphorothioate, triphenyl phosphorothioate, tri Resyl phosphorothioate, trixylenyl phosphorothioate, cresyl diphenyl phosphorothioate, xylenyl diphenyl phosphorothioate, tris (n-propylphenyl) phosphorothionate, tris (isopropylphenyl) phos Phosphorothionate, tris (n-butylphenyl) phosphothionate, tris (isobutylphenyl) phosphothionate, tris (s-butylphenyl) phosphothionate, tris (t-butylphenyl) phosphothionate, etc. ,
Is mentioned.

Moreover, regarding the metal salt of the phosphorus compound represented by the general formula (2) or (3), the hydrocarbon group having 1 to 30 carbon atoms represented by R ^{31 to} R ⁷ in the formula is specifically Includes an alkyl group, a cycloalkyl group, an alkenyl group, an alkylcycloalkyl group, an aryl group, an alkylaryl group, an arylalkyl group, and the like.

  Examples of the alkyl group include methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, and the like. Group, hexadecyl group, heptadecyl group, octadecyl group and other alkyl groups (these alkyl groups may be linear or branched).

  As said cycloalkyl group, C5-C7 cycloalkyl groups, such as a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, can be mentioned, for example. Examples of the alkylcycloalkyl group include a methylcyclopentyl group, a dimethylcyclopentyl group, a methylethylcyclopentyl group, a diethylcyclopentyl group, a methylcyclohexyl group, a dimethylcyclohexyl group, a methylethylcyclohexyl group, a diethylcyclohexyl group, a methylcycloheptyl group, Examples thereof include an alkylcycloalkyl group having 6 to 11 carbon atoms such as a dimethylcycloheptyl group, a methylethylcycloheptyl group, and a diethylcycloheptyl group (the substitution position of the alkyl group with the cycloalkyl group is also arbitrary).

  Examples of the alkenyl group include butenyl, pentenyl, hexenyl, heptenyl, octenyl, nonenyl, decenyl, undecenyl, dodecenyl, tridecenyl, tetradecenyl, pentadecenyl, hexadecenyl, heptadecenyl, An alkenyl group such as an octadecenyl group (these alkenyl groups may be linear or branched, and the position of the double bond is also optional).

  As said aryl group, aryl groups, such as a phenyl group and a naphthyl group, can be mentioned, for example. Examples of the alkylaryl group include tolyl group, xylyl group, ethylphenyl group, propylphenyl group, butylphenyl group, pentylphenyl group, hexylphenyl group, heptylphenyl group, octylphenyl group, nonylphenyl group, and decylphenyl. Group, an alkylaryl group having 7 to 18 carbon atoms such as undecylphenyl group and dodecylphenyl group (the alkyl group may be linear or branched, and the substitution position on the aryl group is arbitrary). .

  Examples of the arylalkyl group include arylalkyl groups having 7 to 12 carbon atoms such as benzyl group, phenylethyl group, phenylpropyl group, phenylbutyl group, phenylpentyl group, and phenylhexyl group. It may be branched).

The hydrocarbon group having 1 to 30 carbon atoms represented by R ^{3 to} R ⁸ is preferably an alkyl group having 1 to 30 carbon atoms or an aryl group having 6 to 24 carbon atoms, more preferably 3 to 3 carbon atoms. An alkyl group having 18 carbon atoms, more preferably an alkyl group having 4 to 12 carbon atoms.

R ³ , R ⁴ and R ⁵ may be the same or different, and each represents a hydrogen atom or the above hydrocarbon group, and 1 to ³ of R ³ , R ⁴ and R ⁵ are the above hydrocarbon groups. It is preferable that 1 to 2 is the above hydrocarbon group, and more preferably 2 is the above hydrocarbon group.

R ⁶ , R ⁷ and R ⁸ may be the same or different and each represents a hydrogen atom or the above hydrocarbon group, and 1 to 3 of R ⁶ , R ⁷ and R ⁸ are the above hydrocarbons. It is preferably a group, 1 to 2 are more preferably the hydrocarbon group, and 2 are more preferably the hydrocarbon group.

In the general formula (2) phosphorus compounds represented by, at least two of X ¹ to X ³ is required to be an oxygen atom, that all the X ¹ to X ³ is an oxygen atom preferable.

Further, the phosphorus compound represented by the general formula (3), but at least three of X ⁴ to X ⁷ is required to be an oxygen atom, all of X ⁴ to X ⁷ is an oxygen atom It is preferable.

  Examples of the phosphorus compound represented by the general formula (2) include phosphorous acid and monothiophosphorous acid; phosphorous acid monoester having one hydrocarbon group having 1 to 30 carbon atoms and monothiophosphorous acid mono Ester; Phosphorous acid diester having two hydrocarbon groups having 1 to 30 carbon atoms, monothiophosphorous acid diester; Phosphorous acid triester having three hydrocarbon groups having 1 to 30 carbon atoms, monothiophosphorous acid Acid triesters; and mixtures thereof. Among these, phosphorous acid monoester and phosphorous acid diester are preferable, and phosphorous acid diester is more preferable.

  Examples of the phosphorus compound represented by the general formula (3) include phosphoric acid and monothiophosphoric acid; phosphoric acid monoester and monothiophosphoric acid monoester having one hydrocarbon group having 1 to 30 carbon atoms; And phosphoric acid diesters and monothiophosphoric acid diesters having two hydrocarbon groups having 1 to 30 carbon atoms; phosphoric acid triesters and monothiophosphoric acid triesters having three hydrocarbon groups having 1 to 30 carbon atoms; and mixtures thereof. It is done. Among these, phosphoric acid monoester and phosphoric acid diester are preferable, and phosphoric acid diester is more preferable.

  Examples of the metal salt of the phosphorus compound represented by the general formula (2) or (3) include a salt obtained by neutralizing part or all of the acidic hydrogen of the phosphorus compound with a metal base. Examples of such metal bases include metal oxides, metal hydroxides, metal carbonates, metal chlorides and the like. Specific examples of the metal include alkali metals such as lithium, sodium, potassium, cesium, and calcium. And alkaline earth metals such as magnesium and barium, and heavy metals such as zinc, copper, iron, lead, nickel, silver, and manganese. Among these, alkaline earth metals such as calcium and magnesium and zinc are preferable.

  The metal salt of the phosphorus compound has a different structure depending on the valence of the metal and the number of OH groups or SH groups of the phosphorus compound. Therefore, the structure is not limited at all. For example, 1 mol of zinc oxide and phosphoric acid diester ( When 2 mol of 1 OH group is reacted, it is considered that a compound having a structure represented by the following formula (4) is obtained as a main component, but it is also considered that polymerized molecules exist.

［式（４）中、ＲはＲ^１〜Ｒ^７と同一の定義内容を示す。］

[In Formula (4), R shows the same definition content as R < ¹ > -R < ⁷ >. ]

  Further, for example, when 1 mol of zinc oxide and 1 mol of phosphoric acid monoester (having two OH groups) are reacted, it is considered that a compound having a structure represented by the following formula (5) is obtained as a main component. Polymerized molecules are also thought to exist.

［式（５）中、ＲはＲ^１〜Ｒ^７と同一の定義内容を示す。］

[In Formula (5), R shows the same definition content as R < ¹ > -R < ⁷ >. ]

  A mixture of two or more of these can also be used.

  In the present embodiment, among the phosphorus compounds, a higher lubricity improving effect is obtained, and therefore, phosphate esters, acidic phosphate esters, and amine salts of acidic phosphate esters are preferable. Those containing phosphorus and / or sulfur are preferred, but those containing phosphorus are particularly preferred. Specific examples include tricresyl phosphate, trilauryl phosphate, trilauryl phosphite, trioleyl phosphite, dilauryl phosphite, dilauryl hydrogen phosphite, and lauric acid phosphate.

  Although the content of the phosphorus compound is arbitrary, it is preferably 0.005% by mass or more and 0.01% by mass or more based on the total amount of the metal processing oil composition from the viewpoint of improving lubricity. More preferably, it is still more preferably 0.05% by mass or more. From the viewpoint of preventing abnormal wear, the content is preferably 10% by mass or less, more preferably 5% by mass or less, and more preferably 3% by mass or less, based on the total amount of the metal working oil composition. Even more preferably.

  In the present embodiment, one of ester, alcohol, and phosphorus compound may be used alone, or two or more may be combined. In particular, the phosphorus compound is preferably used in combination with an ester and / or an alcohol.

  The metal working composition according to this embodiment may further contain a carboxylic acid as a lubricity improver. The carboxylic acid may be a monobasic acid or a polybasic acid. Specific examples include monobasic acids and polybasic acids exemplified in the description of the ester. Among these, a monobasic acid is preferable from the viewpoint of excellent processability.

  The number of carbon atoms of the carboxylic acid used as the lubricity improver is preferably 6 or more, more preferably 8 or more, and even more preferably 10 or more, from the viewpoint of more excellent lubricity improvement effect. Moreover, from the point which suppresses generation | occurrence | production of a stain or corrosion, carbon number of carboxylic acid becomes like this. Preferably it is 20 or less, More preferably, it is 18 or less, More preferably, it is 16 or less.

  Specific preferred examples of the carboxylic acid used as the lubricity improver include lauric acid, myristic acid, palmitic acid and oleic acid.

  The metalworking oil composition according to this embodiment may further contain an extreme pressure agent (sulfur-based extreme pressure agent) containing sulfur as a lubricity improver. As the sulfur-based extreme pressure agent, dihydrocarbyl polysulfide, sulfide ester, sulfide mineral oil, zinc dithiophosphate compound, zinc dithiocarbamate compound, molybdenum dithiophosphate compound and molybdenum dithiocarbamate are preferably used. In particular, it is preferable to use at least one selected from the group consisting of dihydrocarbyl polysulfide and sulfurized ester because the effect of improving lubricity can be obtained at a higher level.

  In order to further improve the excellent effect of the metalworking oil composition according to the present embodiment, an antioxidant, a rust inhibitor, a corrosion inhibitor, an antifoaming agent, and the like may be used alone or as necessary. More than one species may be added in combination.

  Examples of the antioxidant include phenolic compounds such as 2,6-ditertiary butyl-p-cresol (DBPC), aromatic amines such as phenyl-α-naphthylamine, and organometallic compounds such as zinc dialkyldithiophosphate. .

  Examples of rust inhibitors include salts of fatty acids such as oleic acid, sulfonates such as dinonylnaphthalene sulfonate, partial esters of polyhydric alcohols such as sorbitan monooleate, amines and derivatives thereof, phosphate esters and derivatives thereof it can.

  Examples of the corrosion inhibitor include benzotriazole.

  Examples of antifoaming agents include silicone-based ones.

  The total content of these additives is usually 15% by mass or less, preferably 10% by mass or less (both based on the total amount of the metalworking oil composition).

  Moreover, the metalworking oil composition according to this embodiment may further contain water. In this case, the metalworking oil composition according to the present embodiment is an emulsified state in which water is a continuous layer and the oil component is finely dispersed in the continuous layer to form an emulsion; water may be dissolved in the oil component. It may be used either in a solubilized state; or in a suspended state in which water and an oil component are mixed by vigorous stirring.

  When the metalworking oil composition according to this embodiment contains water, tap water, industrial water, ion exchange water, distilled water, or the like can be used as the water, regardless of whether it is hard water or soft water. .

The kinematic viscosity of the metalworking oil composition according to this embodiment is not particularly limited, but the lower limit of the kinematic viscosity at 40 ° C. is preferably 1 mm ² / s, more preferably 2 mm ² / s, and 3 mm ^2. Most preferred is / s. Moreover, the upper limit of the kinematic viscosity at 40 ° C. is preferably 50 mm ² / s, more preferably 30 mm ² / s, and most preferably 20 mm ² / s.
In addition, when the kinematic viscosity at 40 ° C. of the metalworking oil composition is less than 1 mm ² / s, the workability tends to be insufficient. In addition, if the kinematic viscosity exceeds 50 mm ² / s, it is not preferable because over-lubrication occurs and a tool slip may occur during machining.

  Examples of metal processing in which the metal processing oil composition according to the present embodiment is used include rolling (including hot rolling and cold rolling), drawing, ironing, drawing, pressing, forging ( Including hot forging), cutting / grinding, and the like, and particularly preferred for use in cold rolling. In addition, the material of the workpiece used for these metal processing is not particularly limited, for example, iron, stainless steel, aluminum or an alloy thereof, nickel or an alloy thereof, chromium or an alloy thereof, copper or an alloy thereof, zinc or an alloy thereof. , Titanium or an alloy thereof, stainless steel, copper or an alloy thereof, titanium or an alloy thereof, nickel or an alloy thereof, and aluminum specified in JIS H 4000, 5000 series, 6000 series, 7000 series, 8000 series Stainless steel, copper or an alloy thereof, titanium or an alloy thereof, nickel or an alloy thereof is more preferable.

  EXAMPLES Hereinafter, although this invention is demonstrated more concretely based on an Example and a comparative example, this invention is not limited to a following example at all.

[Examples 1 to 10, 12 to 16, 18 to 38, Reference Examples 11 and 17 , Comparative Examples 1 to 17]
Examples 1 to 10, 12 to 16, 18 to 38, Reference Examples 11 and 17, and Comparative Examples 1 to 17 have the compositions shown in Tables 2 to 9 using the base oils and additives shown below, respectively. A metalworking oil composition was prepared.

[Base oil]
Table 1 shows the properties of the base oil.

[Additive]
B1: lauryl alcohol B2: C12-C14 branched alcohol B3: butyl stearate B4: diisononyl adipate B5: tricresyl phosphate
B6: Dilauryl hydrogen phosphite B7: Oleic acid B8: Sulfurized ester

Next, the following evaluation tests were carried out using the lubricating oil compositions of Examples 1 to 10, 12 to 16, 18 to 38, Reference Examples 11 and 17, and Comparative Examples 1 to 17 as sample oils. The test materials used are as follows.
(Test material)
1: JIS SUS304 material (thickness 0.25mm, width 50mm)
2: JIS SUS430 material (thickness 0.25 mm, width 50 mm)
3: Pure copper (thickness 0.3 mm, width 50 mm)
4: Brass (70% copper, 30% zinc) (thickness 0.3 mm, width 50 mm)
5: Pure titanium (thickness 0.23 mm, width 43 mm)
6: Nickel alloy (nickel 60%, iron 40%) (thickness 0.27mm, width 47mm)

[Machinability]
Using the above rolling material and sample oil, using a work roll with a diameter of 51 mm, rolling at a rolling speed of 25 m / min, gradually increasing the rolling reduction from 10%, and rolling reduction starting to cause surface damage such as seizure. Was measured as the critical reduction rate (%).
Confirmation of image sticking was performed by observing the surface of the plate using an optical microscope (400 magnifications) that could not be visually determined. The obtained results are shown in Tables 2-9.

[Surface quality]
Using the above-mentioned rolled material and sample oil, the surface of the material that was rolled at a rolling reduction rate of 15% and a rolling speed of 25 m / min was subjected to image analysis, and the oil pit occupation area ratio (%) was measured. The workability test conditions were compared with those rolled at a rolling reduction rate of 15% and a rolling speed of 10 m / min, and an increase in the oil pit occupying area ratio of less than 5% was evaluated as A, and 5% or more was evaluated as B. . The obtained results are shown in Tables 2-9.

[Odor]
50 g of sample oil was taken in a 300 ml beaker and heated to 30 ° C., and the odor of the sample oil was determined by 10 subjects. 3 points for "I'm worried about odors", 2 points for "I'm worried about odors a little", 1 point for "I don't care about odors", and 0 points for "I don't care about odors" Of less than 1 point was evaluated as A, and 1 or more points were evaluated as B. The obtained results are shown in Tables 2-9.

Claims (4)

A base oil which is a mineral oil having a viscosity index of 70 or more and 115 or less, a sulfur content of 300 mass ppm or more and 1200 mass ppm or less, and a kinematic viscosity at 40 ° C. of ² to 30 mm ² / s ;
At least one lubricity improver selected from esters, alcohols and phosphorus compounds;
A metalworking oil composition comprising:   The metalworking oil composition according to claim 1, which is used for metalworking of a workpiece containing at least one selected from stainless steel, copper, titanium, nickel, and an alloy containing them as a main component.   The metal working oil composition according to claim 2, wherein the metal working is plastic working.   The metalworking oil composition according to claim 2 or 3, wherein the metalworking is cold rolling.