JP4865430B2 - Lubricating oil composition for machine tools - Google Patents

Description

  The present invention relates to a lubricating oil composition for machine tools.

  In the field of machine tools, there is a demand for improved machining accuracy of parts, and accordingly, there is a need for improved positioning accuracy on the sliding guide surface. The performance of the sliding guide surface oil is deeply related to the positioning accuracy on the sliding guide surface, and in addition to low friction (that is, a low friction coefficient), stick-slip gradual reduction is required. Furthermore, the demand for long life and maintenance-free is increasing in lubricating oil for machine tools.

  Therefore, various ideas have been made in the conventional lubricating oil for machine tools in order to meet the above requirements. For example, in order to obtain excellent friction characteristics, phosphoric acid esters and phosphorus compounds such as amine compounds thereof, sulfur compounds such as sulfurized fats and oils, sulfurized esters and the like are used as additives (for example, Patent Documents 1 to 5 below). reference).

In addition, in order to ensure the thermal and oxidation stability of lubricating oil for machine tools, in addition to solvent refined mineral oil as a lubricant base oil, highly refined mineral oil such as hydrorefined mineral oil, hydrocracked mineral oil, and poly α- Synthetic hydrocarbon oils such as olefins are used (see, for example, Patent Documents 6 to 9).
JP 57-67693 A Japanese Patent Laid-Open No. 51-74005 JP-A-8-134488 JP-A-8-209175 JP-A-11-209775 Japanese Patent Laid-Open No. 4-68082 JP 2000-303086 A JP 2002-129180 A JP 2002-129181 A

  However, even the conventional lubricating oil for machine tools still has room for improvement in terms of friction characteristics and stick-slip reduction. Further, the conventional lubricating oil for machine tools does not necessarily have sufficient thermal and oxidation stability from the viewpoint of long life, and further improvement is desired.

  The present invention has been made in view of such circumstances, and can achieve friction characteristics, stick-slip reduction and thermal / oxidation stability at a high level in a well-balanced manner. It is an object to provide a lubricating oil composition for machine tools effective in terms of points.

In order to solve the above-mentioned problems, the present invention is designed to remove a lubricating oil fraction obtained by atmospheric distillation and / or vacuum distillation of a crude oil, solvent extraction, solvent extraction, hydrocracking, solvent dewaxing, catalytic desorption. Select from paraffinic mineral oil, normal paraffinic base oil and isoparaffinic base oil refined by combining one or more of wax, hydrorefining, sulfuric acid washing or clay treatment alone or in combination by weight of at least one lubricating base oil,% _{C a} of 2 or _{less,% C} P /% C _N is 6 or more 35 or less, and the lubricating oil base oil is an iodine value of 2.5 or less, phosphoric acid There is provided a lubricating oil composition for machine tools, comprising at least one selected from monoesters and salts thereof, phosphoric acid diesters and salts thereof, phosphoric acid triesters, sulfurized fats and oils and sulfurized esters .

Since the lubricating base oil contained in the lubricating oil composition for machine tools of the present invention has% C _A ,% C _P /% C _N , and iodine value satisfying the above conditions, respectively, Excellent oxidation stability and friction characteristics. Furthermore, the lubricating base oil is capable of expressing the function of the additive at a higher level while stably dissolving and holding the additive when the additive is blended. Therefore, according to the lubricating oil composition for machine tools of the present invention, the friction characteristics, by the synergistic action of the lubricating base oil having such excellent characteristics and a compound containing phosphorus and / or sulfur as a constituent element, All of stick-slip reduction and thermal / oxidation stability can be achieved in a well-balanced manner at a high level, and high performance of the machine tool can be realized.

  According to the present invention, all of friction characteristics, stick-slip reduction and thermal / oxidation stability can be achieved at a high level in a well-balanced manner, and the lubricating oil composition for machine tools is effective in terms of improving the performance of machine tools. Things can be provided.

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

In the present invention,% C _A of 2 or _less,% C P _/% C _N is 6 or more, the lubricating base oil having an iodine value of 2.5 or less (hereinafter, simply referred to as "lubricating base oil according to the present invention" .) Is used.

% C _A of the lubricating base oil according to the present invention is 2 or less as described above, preferably 1.5 or less, more preferably 1 or less. When% C _A of the lubricating base oil exceeds the upper limit value, the viscosity - temperature characteristic, heat and oxidation stability and frictional properties will be lowered. Moreover,% C _A of the lubricating base oil according to the present invention may be 0% by 0.1 or more C _A, it is possible to further increase the solubility of additives.

The ratio of the lubricating base% in oil _{C P} and% _{C N} of the present invention _{(% C P /% C N} ) is at street 6 or above, and more preferably 7 or more. When% C _P /% _CN is less than the above lower limit, viscosity-temperature characteristics, thermal / oxidative stability and friction characteristics are reduced, and further, when an additive is blended in a lubricating base oil The effectiveness of the agent is reduced. _{Moreover,% C} P /% C _N is preferably 35 or less, more preferably 20 or less, further preferably 14 or less, and particularly preferably 13 or less. % Of C P _/% C _N by the above-described upper limit or less, it is possible to further increase the solubility of additives.

Further, the% C _p of the lubricating base oil according to the present invention is preferably 80 or more, more preferably 82 to 99, still more preferably 85 to 95, and particularly preferably 87 to 93. When% C _p of lubricating base oil is less than the above lower limit, viscosity-temperature characteristics, thermal / oxidative stability, and friction characteristics tend to decrease, and further, additives are added to lubricating base oil In addition, the effectiveness of the additive tends to decrease. Further, when the% C _p value of the lubricating base oil exceeds the upper limit value, the additive solubility will tend to be lower.

Moreover,% _{C N} of the lubricating base oil according to the present invention is preferably 19 or less, more preferably 5 to 15, more preferably 7 to 13, particularly preferably 8 to 12. If the% C _N value of the lubricating base oil exceeds the upper limit value, the viscosity - temperature characteristic, heat and oxidation stability and frictional properties will tend to be reduced. Moreover, when% _CN is less than the said lower limit, it exists in the tendency for the solubility of an additive to fall.

Incidentally, _say% C P in the present invention,% _C A _N and% _{C A,} obtained by a method in accordance with ASTM D 3238-85, respectively (n-d-M ring analysis), the total carbon number of the paraffin carbon number The percentage of the total number of naphthene carbons to the total number of carbons, and the percentage of the total number of aromatic carbons to the total number of carbons. That is, the preferred ranges of% C _P ,% C _N and% C _A described above are based on the values obtained by the above method. For example, even a lubricating base oil containing no naphthene is obtained by the above method. is% C _N may indicate a value greater than zero.

  In addition, the iodine value of the lubricating base oil according to the present invention is 2.5 or less as described above, preferably 1.5 or less, more preferably 1 or less, still more preferably 0.8 or less, Although it may be less than 0.01, it is preferably 0.01 or more, more preferably 0.1 or more, and still more preferably 0.5 or more, from the viewpoint of small effects that are commensurate with it and economy. is there. By setting the iodine value of the lubricating base oil to 2.5 or less, the thermal and oxidation stability can be dramatically improved. The “iodine value” in the present invention means an iodine value measured by an indicator titration method of JIS K 0070 “acid value, saponification value, iodine value, hydroxyl value, and unsaponification value of a chemical product”. .

The lubricating base oil according to the present invention is not particularly limited as long as% C _A ,% C _P /% C _N , and iodine value satisfy the above conditions. Specifically, a lubricating oil fraction obtained by atmospheric distillation and / or vacuum distillation of crude oil is subjected to solvent removal, solvent extraction, hydrocracking, solvent dewaxing, catalytic dewaxing, hydrorefining, sulfuric acid % C _A ,% C among paraffinic mineral oils, normal paraffinic base oils, isoparaffinic base oils, etc., which are refined by combining one or more kinds of purification treatments such as washing and clay treatment alone or in combination of two or more. Examples include _P /% C _N and iodine value satisfying the above conditions. These lubricating base oils may be used alone or in combination of two or more.

As a preferable example of the lubricating base oil according to the present invention, the following base oils (1) to (8) are used as raw materials, and the raw oil and / or the lubricating oil fraction recovered from the raw oil is determined in advance. The base oil obtained by refine | purifying by the refining method of this, and collect | recovering lubricating oil fractions can be mentioned.
(1) Distilled oil by atmospheric distillation of paraffinic crude oil and / or mixed base crude oil (2) Distilled oil by vacuum distillation of atmospheric distillation residue of paraffinic crude oil and / or mixed base crude oil ( WVGO)
(3) Wax (such as slack wax) obtained by the lubricant dewaxing process and / or synthetic wax (Fischer-Tropsch wax, GTL wax, etc.) obtained by the gas-liquid (GTL) process, etc.
(4) One or two or more mixed oils selected from base oils (1) to (3) and / or mild hydrocracking treatment oils of the mixed oils (5) selected from base oils (1) to (4) 2 or more kinds of mixed oils (6) Base oil (1), (2), (3), (4) or (5) debris oil (DAO)
(7) Mild hydrocracking treatment oil (MHC) of base oil (6)
(8) Two or more mixed oils selected from base oils (1) to (7).

  The above-mentioned predetermined purification methods include hydrorefining such as hydrocracking and hydrofinishing; solvent refining such as furfural solvent extraction; dewaxing such as solvent dewaxing and catalytic dewaxing; acid clay and activated clay White clay purification; chemical (acid or alkali) cleaning such as sulfuric acid cleaning and caustic soda cleaning is preferable. In the present invention, one of these purification methods may be performed alone, or two or more may be combined. Moreover, when combining 2 or more types of purification methods, the order in particular is not restrict | limited, It can select suitably.

Furthermore, the lubricating base oil according to the present invention is obtained by subjecting a base oil selected from the above base oils (1) to (8) or a lubricating oil fraction recovered from the base oil to a predetermined treatment. The following base oil (9) or (10) is particularly preferred.
(9) The base oil selected from the base oils (1) to (8) or the lubricating oil fraction recovered from the base oil is hydrocracked and recovered from the product or the product by distillation or the like. Hydrocracked mineral oil obtained by performing dewaxing treatment such as solvent dewaxing or catalytic dewaxing on the lubricating oil fraction, or distillation after the dewaxing treatment (10) The above base oils (1) to (8) ) Or a lubricating oil fraction recovered from the base oil is hydroisomerized, and the product or the lubricating oil fraction recovered from the product by distillation or the like is subjected to solvent dewaxing or catalytic dewaxing. Hydroisomerized mineral oil obtained by performing a dewaxing process such as or by distillation after the dewaxing process.

  Moreover, when obtaining the lubricating base oil of (9) or (10) above, a solvent refining treatment and / or a hydrofinishing treatment step may be further provided as necessary at a convenient step.

  The catalyst used for the hydrocracking / hydroisomerization is not particularly limited, but a composite oxide having cracking activity (for example, silica alumina, alumina boria, silica zirconia, etc.) or one of the composite oxides. Hydrogenolysis with a combination of the above combined with a binder and supporting a metal having hydrogenation ability (for example, one or more metals such as Group VIa metal or Group VIII metal in the periodic table) Hydroisomerization catalyst in which a catalyst or a support containing zeolite (for example, ZSM-5, zeolite beta, SAPO-11, etc.) is loaded with a metal having a hydrogenation ability containing at least one of Group VIII metals Are preferably used. The hydrocracking catalyst and the hydroisomerization catalyst may be used in combination by stacking or mixing.

  The reaction conditions in the hydrocracking / hydroisomerization are not particularly limited, but the hydrogen partial pressure is 0.1 to 20 MPa, the average reaction temperature is 150 to 450 ° C., the LHSV is 0.1 to 3.0 hr-1, and the hydrogen / oil ratio. It is preferable to set it as 50-20000 scf / b.

  Preferable examples of the method for producing a lubricating base oil according to the present invention include production method A shown below.

That is, the manufacturing method A according to the present invention includes:
NH ₃ to the carrier desorption of the fraction of the NH ₃ is 80% or less at 300 to 800 ° C. relative to the total desorption of NH ₃ in the desorption temperature dependence evaluation, at least one of the periodic table Group VIa metals And a first step of preparing a hydrocracking catalyst on which at least one of the Group VIII metals is supported,
In the presence of a hydrocracking catalyst, a feed oil containing 50% by volume or more of slack wax, hydrogen partial pressure 0.1-14 MPa, average reaction temperature 230-430 ° C., LHSV 0.3-3.0 hr ⁻¹ , hydrogen oil ratio A second step of hydrocracking at 50-14000 scf / b;
A third step of obtaining a lubricating oil fraction by distilling and separating the cracked product oil obtained in the second step;
And a fourth step of dewaxing the lubricating oil fraction obtained in the third step.

  Hereinafter, the production method A will be described in detail.

(Raw oil)
In the production method A, a raw material oil containing 50% by volume or more of slack wax is used. The “raw oil containing 50% by volume or more of slack wax” as used in the present invention is a mixed oil of a raw oil consisting only of slack wax, slack wax and other raw material oil, and 50 volumes of slack wax. % And both raw material oils containing at least% are included.

Slack wax is a wax-containing component by-produced in the solvent dewaxing step when producing a lubricating base oil from a paraffinic lubricating oil fraction. In the present invention, the slack wax is obtained by further deoiling the wax-containing component. Included in wax. The main components of slack wax are n-paraffins and branched paraffins (isoparaffins) with few side chains, and are low in naphthenes and aromatics. The kinematic viscosity of the slack wax used for the preparation of the raw material oil can be appropriately selected according to the kinematic viscosity of the target lubricating base oil, but a low viscosity base oil is produced as the lubricating base oil according to the present invention. For this purpose, a relatively low viscosity slack wax having a kinematic viscosity at 100 ° C. of about ² to 25 mm ² / s, preferably about 2.5 to ²⁰ mm ² / s, more preferably about 3 to 15 mm ² / s. desirable. Moreover, although the other property of slack wax is also arbitrary, melting | fusing point becomes like this. Preferably it is 35-80 degreeC, More preferably, it is 45-70 degreeC, More preferably, it is 50-60 degreeC. The oil content of the slack wax is preferably not more than mass%, more preferably not more than 50 mass%, still more preferably not more than 25 mass%, particularly preferably not more than 10 mass%, and preferably not less than 0.5 mass%. More preferably, it is 1% by mass or more. The sulfur content of the slack wax is preferably 1% by mass or less, more preferably 0.5% by mass or less, and preferably 0.001% by mass or more.

  Here, the oil content of the fully deoiled slack wax (hereinafter referred to as “slack wax A”) is preferably 0.5 to 10% by mass, more preferably 1 to 8% by mass. The sulfur content of the slack wax A is preferably 0.001 to 0.2% by mass, more preferably 0.01 to 0.15% by mass, and still more preferably 0.05 to 0.12% by mass. On the other hand, the oil content of slack wax (hereinafter referred to as “slack wax B”) that is not deoiled or insufficiently deoiled is preferably 10 to 60% by mass, more preferably 12 to 50% by mass. More preferably, it is 15 to 25% by mass. The sulfur content of the slack wax B is preferably 0.05 to 1% by mass, more preferably 0.1 to 0.5% by mass, and still more preferably 0.15 to 0.25% by mass. The slack waxes A and B may be subjected to a desulfurization treatment depending on the type and characteristics of the hydrocracking / isomerization catalyst, and the sulfur content in that case is preferably 0.01. It is at most mass%, more preferably at most 0.001 mass%.

In the above-described manufacturing method A, by using the slack wax A as a raw _{material,% C A,% C P} /% C N and the iodine value obtained suitably such lubricating base oil in each of the above conditions are satisfied the present invention be able to. In addition, according to the above production method A, even if slack wax B having a relatively high oil content and sulfur content, and relatively poor and inexpensive is used as a raw material, the viscosity index is high, and low temperature characteristics and thermal / oxidative stability are excellent. In addition, a lubricating base oil with high added value can be obtained.

  When the raw material oil is a mixed oil of slack wax and other raw material oil, the other raw material oil is not particularly limited as long as the ratio of slack wax to the total amount of the mixed oil is 50% by volume or more. A heavy oil-distilled distillate and / or a mixed oil of vacuum-distilled distillate is preferably used.

  Further, when the raw material oil is a mixed oil of slack wax and another raw material oil, the ratio of slack wax in the mixed oil is more preferably 70% by volume or more from the viewpoint of producing a base oil having a high viscosity index. 75% by volume or more is even more preferable. When the ratio is less than 50% by volume, the oil base such as aromatics and naphthenes in the obtained lubricating base oil tends to increase and the viscosity index of the lubricating base oil tends to decrease.

  On the other hand, the heavy atmospheric distillation distillate and / or vacuum distillation distillate of crude oil used in combination with slack wax has a distillation temperature of 300 to 570 ° C. in order to keep the viscosity index of the lubricating base oil produced high. A fraction having a distillate component of 60% by volume or more in the range is preferable.

(Hydrocracking catalyst)
In the manufacturing method A, the carrier desorption of the fraction of the NH ₃ is 80% or less at 300 to 800 ° C. relative to the total desorption of NH ₃ in the NH ₃ desorption temperature dependence evaluation, periodic table Group VIa A hydrocracking catalyst in which at least one of the metals and at least one of the Group VIII metals is supported is used.

Here, “NH ₃ desorption temperature dependency evaluation” refers to literature (Sawa M., Niwa M., Murakami Y., Zeolites 1990, 10, 532, Karge HG, Dondur V., J. Phys. Chem., 1990, 94, 765, etc.) and is performed as follows. First, the catalyst carrier is pretreated at a temperature of 400 ° C. or higher for 30 minutes or more under a nitrogen stream to remove adsorbed molecules, and then adsorbs NH ₃ at 100 ° C. until saturation. Then, the catalyst support to 100 to 800 ° C. 10 ° C. / min was heated by the following heating rate desorbed NH _3, to monitor the NH ₃ separated at every predetermined temperature by desorption. Then, the fraction of the NH ₃ desorption amount at 300 ° C. to 800 ° C. with respect to the total NH ₃ desorption amount (desorption amount at 100 to 800 ° C.) is obtained.

The catalyst carrier used in the production method A are those desorption of the fraction of NH ₃ at 300 to 800 ° C. relative to the total desorption of NH ₃ in the NH ₃ desorption temperature dependence evaluation of the following 80% , Preferably 70% or less, more preferably 60% or less. By constituting a hydrocracking catalyst using such a carrier, the acid properties that govern the cracking activity are sufficiently suppressed, so that the high molecular weight n-paraffin derived from slack wax or the like in the raw oil by hydrocracking. The production of isoparaffin by decomposition isomerization can be performed efficiently and reliably, and excessive decomposition of the produced isoparaffin compound can be sufficiently suppressed. As a result, a sufficient amount of molecules having a moderately branched chemical structure and a high viscosity index can be provided in an appropriate molecular weight range.

  As such a support, a binary oxide which is amorphous and has an acid property is preferable. For example, it is exemplified in the literature ("Metal oxide and its catalytic action", Tetsuro Shimizu, Kodansha, 1978). And binary oxides.

Among them, an amorphous composite oxide which is an acid composed of two kinds of oxides of elements selected from Al, B, Ba, Bi, Cd, Ga, La, Mg, Si, Ti, W, Y, Zn and Zr. It is preferable to contain a property binary oxide. By adjusting the ratio of each oxide of these acid property binary oxides, a support having an acid property suitable for this purpose can be obtained in the NH ₃ adsorption / desorption evaluation. In addition, the acid property binary oxide constituting the carrier may be one of the above or a mixture of two or more. Further, the carrier may be composed of the above-mentioned acid property binary oxide, or may be a carrier obtained by binding the acid property binary oxide with a binder.

  Further, the carrier is amorphous silica / alumina, amorphous silica / zirconia, amorphous silica / magnesia, amorphous silica / titania, amorphous silica / boria, amorphous alumina / zirconia, amorphous alumina / magnesia, amorphous At least one selected from alumina / titania, amorphous alumina / boria, amorphous zirconia / magnesia, amorphous zirconia / titania, amorphous zirconia / boria, amorphous magnesia / titania, amorphous magnesia / boria and amorphous titania / boria It is preferable to contain two kinds of acid nature binary oxides. The acidic binary oxide constituting the carrier may be one of the above or a mixture of two or more. Further, the carrier may be composed of the above-mentioned acid property binary oxide, or may be a carrier obtained by binding the acid property binary oxide with a binder. The binder is not particularly limited as long as it is generally used for catalyst preparation, but is preferably selected from silica, alumina, magnesia, titania, zirconia, clay, or a mixture thereof.

  In the production method A described above, the carrier is composed of at least one of group VIa metals (molybdenum, chromium, tungsten, etc.) of the periodic table and group VIII metal (nickel, cobalt, palladium, platinum, etc.). At least one of them is supported to form a hydrocracking catalyst. These metals are responsible for hydrogenation ability, terminate the reaction in which the paraffinic compound is decomposed or branched by the acidic carrier, and play an important role in producing isoparaffin having an appropriate molecular weight and branched structure.

  As the amount of metal supported in the hydrocracking catalyst, the supported amount of Group VIa metal is 5 to 30% by mass per one type of metal, and the supported amount of Group VIII metal is 0.2 to 10% by mass per one type of metal. % Is preferred.

  Further, in the hydrocracking catalyst used in the production method A, molybdenum is contained in the range of 5 to 30% by mass as one or more metals of the Group VIa metal, and one or more of the Group VIII metals is contained. More preferably, the metal contains nickel in the range of 0.2 to 10% by mass.

  The hydrocracking catalyst composed of the above support and one or more metals of Group VIa metal and one or more metals of Group VIII metal is preferably used for hydrocracking in a sulfurized state. The sulfurization treatment can be performed by a known method.

(Hydrolysis process)
In the production method A, a raw material oil containing 50% by volume or more of slack wax in the presence of the hydrocracking catalyst has a hydrogen partial pressure of 0.1 to 14 MPa, preferably 1 to 14 MPa, more preferably 2 to 2. 7 MPa; average reaction temperature of 230 to 430 ° C., preferably 330 to 400 ° C., more preferably 350 to 390 ° C .; LHSV of 0.3 to 3.0 hr ⁻¹ , preferably 0.5 to 2.0 hr ⁻¹ ; Hydrogenolysis is performed at a hydrogen oil ratio of 50 to 14,000 scf / b, preferably 100 to 5000 scf / b.

  In such a hydrocracking process, isomerization to isoparaffin progresses in the process of cracking n-paraffin derived from slack wax in the raw material oil, thereby producing an isoparaffin component having a low pour point and a high viscosity index. At the same time, it breaks down aromatic compounds, which are inhibitors of high viscosity index contained in the feedstock, into monocyclic aromatic compounds, naphthene compounds and paraffin compounds, and inhibits high viscosity index. The polycyclic naphthene compound as a factor can be decomposed into a monocyclic naphthene compound or a paraffin compound. From the viewpoint of increasing the viscosity index, it is preferable that the raw material oil contains fewer compounds having a high boiling point and a low viscosity index.

Further, the decomposition rate for evaluating the progress of the reaction is expressed by the following formula:
(Decomposition rate (volume%)) = 100− (ratio of the fraction having a boiling point of 360 ° C. or more in the product (volume%))
In this way, the decomposition rate is preferably 3 to 90% by volume. When the decomposition rate is less than 3% by volume, isoparaffins are generated by decomposition and isomerization of high-molecular-weight n-paraffins having a high pour point contained in the feedstock, and hydrocracking of aromatics and polycyclic naphthenes with poor viscosity index. When the decomposition rate exceeds 90% by volume, the yield of the lubricating oil fraction decreases, which is not preferable.

(Distillation separation process)
Next, the lubricating oil fraction is distilled and separated from the cracked product oil obtained by the hydrocracking step. At this time, a fuel oil fraction may be obtained as a light component.

  The fuel oil fraction is a fraction obtained as a result of sufficient desulfurization and denitrogenation, and sufficient aromatic hydrogenation. Among these, the naphtha fraction has a high isoparaffin content, the kerosene fraction has a high smoke point, and the light oil fraction has a high cetane number.

  On the other hand, when hydrocracking in the lubricating oil fraction is insufficient, a part of it may be subjected to the hydrocracking process again. Further, in order to obtain a lubricating oil fraction having a desired kinematic viscosity, the lubricating oil fraction may be further distilled under reduced pressure. This vacuum distillation separation may be performed after the dewaxing treatment described below.

  In the evaporative separation step, a lubricant base oil called 70 Pale, SAE10, or SAE20 can be suitably obtained by distilling the cracked product oil obtained in the hydrocracking step under reduced pressure.

  A system that uses slack wax with lower viscosity as the feedstock is suitable for producing a large amount of 70 Pale and 10 SAE fractions, and a system that uses slack wax with a high viscosity within the above range as feedstock produces a lot of SAE20. Suitable for doing. However, even if a high-viscosity slack wax is used, conditions for generating a considerable amount of 70 Pale and SAE 10 can be selected depending on the progress of the decomposition reaction.

(Dewaxing process)
In the above-described distillation separation step, since the lubricating oil fraction fractionated from the cracked product oil has a high pour point, it is dewaxed to obtain a lubricating base oil having a desired pour point. The dewaxing treatment can be performed by a usual method such as a solvent dewaxing method or a contact dewaxing method. Among these, the solvent dewaxing method generally uses a mixed solvent of MEK and toluene, but may use a solvent such as benzene, acetone, MIBK or the like. In order to make the pour point of the dewaxed oil not more than −10 ° C., the solvent / oil ratio is 1 to 6 times, and the filtration temperature is −5 to −45 ° C., preferably −10 to −40 ° C. The wax removed here can be used again as a slack wax in the hydrocracking step.

  In the said manufacturing method, you may add a solvent refinement | purification process and / or a hydrorefining process to a dewaxing process. These additional treatments are performed in order to improve the ultraviolet stability and oxidation stability of the lubricating base oil, and can be carried out by a method used in a normal lubricating oil refining process.

  In the solvent purification, furfural, phenol, N-methylpyrrolidone or the like is generally used as a solvent, and a small amount of aromatic compounds, particularly polycyclic aromatic compounds remaining in the lubricating oil fraction are removed.

In addition, hydrorefining is performed to hydrogenate olefin compounds and aromatic compounds, and the catalyst is not particularly limited. However, at least one of Group VIa metals such as molybdenum, cobalt, nickel, etc. Using an alumina catalyst supporting at least one of the Group VIII metals, the reaction pressure (hydrogen partial pressure) is 7 to 16 MPa, the average reaction temperature is 300 to 390 ° C., and the LHSV is 0.5 to 4.0 hr ⁻¹ . Can be done below.

  Moreover, as a preferable example of the manufacturing method of the lubricating base oil according to the present invention, the following manufacturing method B can be mentioned.

That is, the production method B according to the present invention is:
A fifth step of hydrocracking and / or hydroisomerizing a feedstock containing paraffinic hydrocarbons in the presence of a catalyst;
A sixth step of dewaxing the product obtained in the fifth step or the lubricating oil fraction recovered from the product by distillation or the like;
Is provided.

  Hereinafter, the production method B will be described in detail.

(Raw oil)
In the production method B, a raw material oil containing paraffinic hydrocarbon is used. The “paraffinic hydrocarbon” referred to in the present invention means a hydrocarbon having a paraffin molecule content of 70% by mass or more. The carbon number of the paraffinic hydrocarbon is not particularly limited, but usually about 10 to 100 is used. The paraffinic hydrocarbon production method is not particularly limited, and various paraffinic hydrocarbons such as petroleum and synthetic can be used. Particularly preferable paraffinic hydrocarbons include a gas-liquid (GTL) process and the like. Synthetic waxes obtained (Fischer-Tropsch wax (FT wax), GTL wax, etc.) can be mentioned, among which FT wax is preferred. The synthetic wax is preferably a wax containing, as a main component, a normal paraffin having 15 to 80 carbon atoms, more preferably 20 to 50 carbon atoms.

The kinematic viscosity of the paraffinic hydrocarbon used in the preparation of the raw material oil can be appropriately selected according to the kinematic viscosity of the target lubricating base oil, but the low viscosity base oil is used as the lubricating base oil according to the present invention. To produce a relatively low viscosity paraffin having a kinematic viscosity at 100 ° C. of about ² to 25 mm ² / s, preferably about 2.5 to ²⁰ mm ² / s, more preferably about 3 to 15 mm ² / s. Series hydrocarbons are desirable. In addition, other properties of the paraffinic hydrocarbon are optional, but when the paraffinic hydrocarbon is a synthetic wax such as FT wax, the melting point is preferably 35 to 80 ° C, more preferably 50 to 80 ° C, More preferably, it is 60-80 degreeC. The oil content of the synthetic wax is preferably 10% by mass or less, more preferably 5% by mass or less, and further preferably 2% by mass or less. Further, the sulfur content of the synthetic wax is preferably 0.01% by mass or less, more preferably 0.001% by mass or less, and further preferably 0.0001% by mass or less.

  When the raw material oil is a mixed oil of the above synthetic wax and another raw material oil, the other raw material oil is not particularly limited as long as the ratio of the synthetic wax to the total amount of the mixed oil is 50% by volume or more. A heavy atmospheric distillation oil and / or a mixed oil of reduced pressure distillation oil is preferably used.

  Further, when the raw material oil is a mixed oil of the above synthetic wax and other raw material oils, the proportion of the synthetic wax in the mixed oil is more than 70% by volume from the viewpoint of producing a base oil having a high viscosity index. Preferably, 75% by volume or more is even more preferable. If the ratio is less than 70% by volume, the lubricating base oil to be obtained tends to increase the oil content such as aromatics and naphthenes and decrease the viscosity index of the lubricating base oil.

  On the other hand, heavy crude pressure distillation distillate and / or vacuum distillation distillate of crude oil used in combination with synthetic wax is used at a distillation temperature of 300 to 570 ° C. in order to keep the viscosity index of the lubricating base oil to be produced high. A fraction having a distillate component of 60% by volume or more in the range is preferable.

(catalyst)
The catalyst used in production method B is not particularly limited, but a catalyst in which at least one selected from Group VI metal and Group VIII metal of the periodic table as an active metal component is supported on a support containing aluminosilicate. Preferably used.

  Aluminosilicate refers to a metal oxide composed of three elements of aluminum, silicon, and oxygen. Further, other metal elements can be allowed to coexist within a range that does not hinder the effects of the present invention. In this case, the amount of the other metal element is preferably 5% by mass or less, and more preferably 3% by mass or less of the total amount of alumina and silica as the oxide. Examples of metal elements that can coexist include titanium, lanthanum, manganese, and the like.

The crystallinity of aluminosilicate can be estimated by the proportion of tetracoordinate aluminum atoms in all aluminum atoms, and this proportion can be measured by ²⁷ Al solid state NMR. As the aluminosilicate used in the present invention, the ratio of tetracoordinated aluminum to the total amount of aluminum is preferably 50% by mass or more, more preferably 70% by mass or more, and further preferably 80% by mass or more. Hereinafter, an aluminosilicate in which the ratio of tetracoordinated aluminum to the total amount of aluminum is 50% by mass or more is referred to as “crystalline aluminosilicate”.

  As the crystalline aluminosilicate, so-called zeolite can be used. Preferable examples include Y-type zeolite, ultra-stable Y-type zeolite (USY-type zeolite), β-type zeolite, mordenite, ZSM-5, etc. Among them, USY zeolite is particularly preferable. In the present invention, one type of crystalline aluminosilicate may be used alone, or two or more types may be used in combination.

  Examples of a method for preparing a carrier containing crystalline aluminosilicate include a method of molding a mixture of crystalline aluminosilicate and a binder and firing the molded body. The binder to be used is not particularly limited, but alumina, silica, silica alumina, titania and magnesia are preferable, and alumina is particularly preferable. The use ratio of the binder is not particularly limited, but is usually preferably 5 to 99% by mass and more preferably 20 to 99% by mass based on the total amount of the molded body. 430-470 degreeC is preferable, as for the baking temperature of the molded object containing a crystalline aluminosilicate and a binder, 440-460 degreeC is more preferable, and 445-455 degreeC is more preferable. The firing time is not particularly limited, but is usually 1 minute to 24 hours, preferably 10 minutes to 20 hours, more preferably 30 minutes to 10 hours. Firing may be performed in an air atmosphere, but is preferably performed in an oxygen-free atmosphere such as a nitrogen atmosphere.

  Examples of the Group VI b metal supported on the carrier include chromium, molybdenum, tungsten, and the like. Specific examples of the Group VIII metal include cobalt, nickel, rhodium, palladium, iridium, platinum, and the like. It is done. These metals may be used individually by 1 type, or may be used in combination of 2 or more types. When two or more kinds of metals are combined, noble metals such as platinum and palladium may be combined, base metals such as nickel, cobalt, tungsten and molybdenum may be combined, or a noble metal and a base metal may be combined.

  Further, the loading of the metal on the carrier can be performed by information such as impregnation of the carrier into a solution containing the metal, ion exchange, and the like. The amount of the metal supported can be appropriately selected, but is usually 0.05 to 2% by mass, preferably 0.1 to 1% by mass based on the total amount of the catalyst.

(Hydrolysis / Hydroisomerization process)
In the production method B, the feedstock oil containing paraffinic hydrocarbon is hydrocracked / hydroisomerized in the presence of the catalyst. Such hydrocracking / hydroisomerization step can be performed using a fixed bed reactor. As conditions for hydrocracking / hydroisomerization, for example, the temperature is preferably 250 to 400 ° C., the hydrogen pressure is preferably 0.5 to 10 MPa, and the liquid space velocity (LHSV) of the feedstock is preferably 0.5 to 10 h ^−1. .

(Distillation separation process)
Next, the lubricating oil fraction is distilled and separated from the cracked product oil obtained by the hydrocracking / hydroisomerization step. In addition, since the distillation separation process in the manufacturing method B is the same as the distillation separation process in the manufacturing method A, the overlapping description is abbreviate | omitted here.

(Dewaxing process)
Subsequently, the lubricating oil fraction fractionated from the cracked product oil in the distillation separation step is dewaxed. Such a dewaxing step can be performed using a conventionally known dewaxing process such as solvent dewaxing or catalytic dewaxing. Here, if the substance having a boiling point of 370 ° C. or less present in the cracked / isomerized product oil is not separated from the high boiling point substance prior to dewaxing, depending on the use of the cracked / isomerized product oil, The compound may be dewaxed or a fraction having a boiling point of 370 ° C. or higher may be dewaxed.

  In solvent dewaxing, the hydroisomerized product is contacted with chilled ketone and acetone, and other solvents such as MEK, MIBK, and further cooled to precipitate the high pour point material as a waxy solid, which is precipitated with raffinate. Separate from a solvent-containing lubricating oil fraction. Further, the raffinate can be cooled with a scraped surface chiller to remove wax solids. Low molecular weight hydrocarbons such as propane can also be used for dewaxing. In this case, the cracked / isomerized product oil and the low molecular weight hydrocarbon are mixed and at least a part thereof is vaporized to decompose / isomerize. The product oil is further cooled to precipitate the wax. The wax is separated from the raffinate by filtration, membrane or centrifugation. Thereafter, the solvent is removed from the raffinate, and the raffinate is fractionally distilled to obtain the target lubricating base oil.

  In the case of catalytic dewaxing (catalyst dewaxing), the cracked / isomerized product oil is reacted with hydrogen in the presence of a suitable dewaxing catalyst under conditions effective to lower the pour point. In catalytic dewaxing, some of the high-boiling substances in the cracking / isomerization product are converted to low-boiling substances, the low-boiling substances are separated from the heavier base oil fraction, and the base oil fraction is fractionated. Two or more kinds of lubricating base oils are obtained. The low-boiling substances can be separated before obtaining the target lubricating base oil or during fractional distillation.

  The dewaxing catalyst is not particularly limited as long as it can lower the pour point of the cracked / isomerized product oil, but the desired lubricating base oil is obtained from the cracked / isomerized product oil in a high yield. Those that can be used are preferred. As such a dewaxing catalyst, a shape selective molecular sieve (molecular sieve) is preferable, and specifically, ferrierite, mordenite, ZSM-5, ZSM-11, ZSM-23, ZSM-35, ZSM-22 ( And theta aluminophosphates (SAPO) and the like. These molecular sieves are preferably used in combination with a catalytic metal component, and more preferably in combination with a noble metal. A preferable combination includes, for example, a composite of platinum and H-mordenite.

The dewaxing conditions are not particularly limited, but the temperature is preferably 200 to 500 ° C., and the hydrogen pressure is preferably 10 to 200 bar (1 MPa to 20 MPa). In the case of a flow-through reactor, the H ₂ treatment rate is preferably 0.1 to 10 kg / l / hr, and the LHSV is preferably 0.1 to 10 ^{−1 and} more preferably 0.2 to 2.0 h ^−1. . Dewaxing refers to a substance having an initial boiling point of 350 to 400 ° C., usually 40% by mass or less, preferably 30% by mass or less, contained in the cracked / isomerized product oil, having a boiling point lower than the initial boiling point. It is preferable to carry out the conversion to a substance having the same.

  As mentioned above, although the manufacturing method A and the manufacturing method B which are the preferable manufacturing methods of the lubricant base oil concerning this invention were demonstrated, the manufacturing method of the lubricant base oil concerning this invention is not limited to these. For example, in the above production method A, synthetic waxes such as FT wax and GTL wax may be used instead of slack wax. In the production method B, a raw material oil containing slack wax (preferably slack wax A, B) may be used. Furthermore, in each of the production methods A and B, slack wax (preferably slack wax A and B) and synthetic wax (preferably FT wax and GTL wax) may be used in combination.

  In addition, when the raw material oil used when manufacturing the lubricating base oil according to the present invention is a mixed oil of the above-described slack wax and / or synthetic wax and a raw material oil other than these waxes, slack wax The content of the synthetic wax is preferably 50% by mass or more based on the total amount of the raw material oil.

  The raw material oil for producing the lubricating base oil according to the present invention is a raw material oil containing slack wax and / or synthetic wax, and the oil content is preferably 60% by mass or less, more preferably 50% by mass. % Or less, more preferably 25% by mass or less.

  Further, the content of the saturated component in the lubricating base oil according to the present invention is preferably 90% by mass or more, more preferably 93% by mass or more, and still more preferably 95% by mass or more, based on the total amount of the lubricating base oil. In addition, the ratio of the cyclic saturated component in the saturated component is preferably 40% by mass or less, more preferably 0.1 to 40% by mass, still more preferably 2 to 30% by mass, and still more preferably 5 to 5% by mass. It is 25 mass%, Most preferably, it is 10-21 mass%. By satisfying the above conditions for the content of the saturated component and the ratio of the cyclic saturated component in the saturated component, the viscosity-temperature characteristics and thermal / oxidative stability can be achieved at a higher level, and the lubrication When an additive is blended in the oil base oil, the function of the additive can be expressed at a higher level while the additive is sufficiently stably dissolved and held in the lubricant base oil. Furthermore, it is possible to improve the friction characteristics of the lubricating base oil itself, and as a result, it is possible to achieve an improvement in friction reduction effect and an improvement in energy saving.

  In addition, when content of a saturated part is less than 90 mass%, it exists in the tendency for a viscosity-temperature characteristic, thermal / oxidation stability, and a friction characteristic to become inadequate. Moreover, when the ratio of the cyclic | annular saturated part to a saturated part exceeds 40 mass%, when an additive is mix | blended with lubricating base oil, it exists in the tendency for the effectiveness of the said additive to fall. Furthermore, when the ratio of the cyclic saturated component to the saturated component is less than 0.1% by mass, when the additive is blended with the lubricating base oil, the solubility of the additive is reduced and the lubricating base oil The effective amount of the additive dissolved and retained tends to decrease, and the function of the additive cannot be effectively obtained. Further, the content of the saturated component may be 100% by mass, but is preferably 99.9% by mass or less, more preferably 99.5% by mass or less, from the viewpoint of reducing the production cost and improving the solubility of the additive. More preferably, it is 99 mass% or less, Most preferably, it is 98.5 mass% or less.

  In the lubricating base oil according to the present invention, the ratio of the cyclic saturated component in the saturated component is 40% by mass or less is equivalent to the non-cyclic saturated component in the saturated component being 60% by mass or more. . Here, the non-cyclic saturated component includes both a linear paraffin component and a branched paraffin component. The proportion of each paraffin component in the lubricating base oil according to the present invention is not particularly limited, but the proportion of the branched paraffin component is preferably 55 to 99 mass%, more preferably 57. It is 5-96 mass%, More preferably, it is 60-95 mass%, More preferably, it is 70-92 mass%, Most preferably, it is 80-90 mass%. When the ratio of the branched paraffin content in the lubricating base oil satisfies the above conditions, the viscosity-temperature characteristics and thermal / oxidative stability can be further improved, and an additive is added to the lubricating base oil. In this case, the function of the additive can be expressed at a higher level while the additive is sufficiently stably dissolved and held. The proportion of linear paraffin in the lubricating base oil is preferably 1% by mass or less, more preferably 0.5% by mass or less, and even more preferably 0.2% by mass or less, based on the total amount of the lubricating oil base oil. It is. When the ratio of the straight-chain paraffin satisfies the above conditions, a lubricating base oil having more excellent low-temperature viscosity characteristics can be obtained.

  Further, in the lubricating base oil according to the present invention, the content of the saturated component of one ring and the saturated component of two or more rings in the saturated component is not particularly limited, but the ratio of the saturated component of two or more rings in the saturated component is It is preferably 0.1% by mass or more, more preferably 1% by mass or more, further preferably 3% by mass or more, particularly preferably 5% by mass or more, and 40% by mass. The content is preferably 20% by mass or less, more preferably 15% by mass or less, and particularly preferably 11% by mass or less. Further, the percentage of saturated one ring in the saturated portion may be 0% by mass, preferably 1% by mass or more, more preferably 2% by mass or more, still more preferably 3% by mass or more, particularly preferably 4%. Further, it is preferably 40% by mass or less, more preferably 20% by mass or less, still more preferably 15% by mass or less, and particularly preferably 11% by mass or less.

Further, in the lubricating base oil according to the present invention, the ratio of the monocyclic saturated component of the mass contained in the cyclic saturated components (M _A) and 2 rings or more saturated components mass _{(M B) (M A /} M B ) Is preferably 20 or less, more preferably 3 or less, still more preferably 2 or less, and particularly preferably 1 or less. _Although it may be a 0 M A / _{M B,} preferably 0.1 or more, more preferably 0.3 or more, more preferably 0.5 or more. By the above condition is satisfied M A _/ M _B, the viscosity - a temperature characteristic and heat and oxidation stability can be further compatible at a high level.

Moreover, in the lubricating base oil according to the present invention, the ratio (M _A / M _c ) between the mass of the monocyclic saturated component (M _A ) and the mass of the bicyclic saturated component (M _c ) contained in the cyclic saturated component is , Preferably 3 or less, more preferably 1.5 or less, still more preferably 1.3 or less, particularly preferably 1.2 or less. _Although it may be a the _M A / M _c 0, preferably 0.1 or more, more preferably 0.3 or more, more preferably 0.5 or more. By satisfying the above conditions for M _A / M _c , the viscosity-temperature characteristics and the heat / oxidation stability can be achieved at a higher level.

  In addition, content of the saturated part said by this invention means the value (unit: mass%) measured based on ASTM D 2007-93.

  Further, the ratios of the cyclic saturated component, the single ring saturated component, the two or more saturated components and the non-cyclic saturated component in the saturated component as used in the present invention are naphthenic components measured in accordance with ASTM D 2786-91, respectively. (Measuring target: 1-ring to 6-ring naphthene, unit: mass%) and alkane content (unit: mass%).

In addition, the linear paraffin content in the lubricating base oil referred to in the present invention is the gas chromatographic analysis of the saturated content separated and separated by the method described in ASTM D 2007-93 under the following conditions. The value obtained by converting the measured value when the linear paraffin content in the saturated content is identified and quantified based on the total amount of the lubricating base oil is meant. In the identification and quantification, a mixed sample of straight-chain paraffin having 5 to 50 carbon atoms is used as a standard sample, and the straight-chain paraffin content in the saturated portion is the total peak area value of the chromatogram (in the diluent). It is determined as the ratio of the sum of peak area values corresponding to each linear paraffin to (excluding the peak area value derived from).
(Gas chromatography conditions)
Column: non-polar liquid phase column (length 25 mm, inner diameter 0.3 mmφ, liquid phase film thickness 0.1 μm)
Temperature rising condition: 50 ° C. to 400 ° C. (temperature rising rate: 10 ° C./min)
Carrier gas: helium (linear velocity: 40 cm / min)
Split ratio: 90/1
Sample injection amount: 0.5 μL (injection amount of sample diluted 20 times with carbon disulfide)

  The ratio of branched paraffin in the lubricating base oil is the difference between the non-cyclic saturated content in the saturated content and the linear paraffin content in the saturated content, converted based on the total amount of the lubricating base oil. Means the value.

  In the case of a method for separating saturated components, or a compositional analysis of cyclic saturated components, non-cyclic saturated components, etc., a similar method can be used in which similar results can be obtained. For example, in addition to the above, a method described in ASTM D 2425-93, a method described in ASTM D 2549-91, a method using high performance liquid chromatography (HPLC), a method obtained by improving these methods, and the like can be given.

Also, the aromatic content in the lubricating base oil according to the present _{invention,% C A,% C P} /% C N, and although the iodine value is not particularly limited as long as the above conditions are satisfied, lubricating base oils the total amount Is preferably 7% by mass or less, more preferably 5% by mass or less, further preferably 4% by mass or less, particularly preferably 3% by mass or less, and preferably 0.1% by mass or more, more preferably Is 0.5% by mass or more, more preferably 1% by mass or more, and particularly preferably 1.5% by mass or more. If the aromatic content exceeds the above upper limit, the viscosity-temperature characteristics, thermal / oxidative stability, friction characteristics, volatilization prevention characteristics and low-temperature viscosity characteristics tend to decrease. When an additive is blended with the additive, the effectiveness of the additive tends to decrease. Moreover, the lubricating base oil according to the present invention may not contain an aromatic component, but by further increasing the solubility of the additive by setting the aromatic content to the above lower limit or more. Can do.

  In addition, the aromatic component as used in the field of this invention means the value measured based on ASTM D 2007-93. In general, the aromatic component includes alkylbenzene, alkylnaphthalene, anthracene, phenanthrene and alkylated products thereof, as well as compounds in which four or more benzene rings are condensed, pyridines, quinolines, phenols and naphthols. Aromatic compounds having atoms are included.

  The viscosity index of the lubricating base oil according to the present invention is preferably 110 or more. When the viscosity index is less than the lower limit, viscosity-temperature characteristics, thermal / oxidation stability, and further volatilization prevention properties tend to decrease. The preferred range of the viscosity index of the lubricating base oil according to the present invention depends on the viscosity grade of the lubricating base oil, and will be described in detail later.

Other properties of the lubricating base oil according to the present _{invention,% C A,% C P} /% C N, and although the iodine value is not particularly limited as long as each of the above conditions are satisfied, the lubricating oil according to the present invention The base oil preferably has various properties shown below.

  The sulfur content in the lubricating base oil according to the present invention depends on the sulfur content of the raw material. For example, when a raw material that does not substantially contain sulfur such as a synthetic wax component obtained by a Fischer-Tropsch reaction or the like is used, a lubricating base oil that does not substantially contain sulfur can be obtained. In addition, when using raw materials containing sulfur such as slack wax obtained in the refining process of the lubricating base oil and microwax obtained in the refining process, the sulfur content in the obtained lubricating base oil is usually 100 mass ppm. That's it. In the lubricating base oil according to the present invention, the content of sulfur is preferably 100 ppm by mass or less, more preferably 50 ppm by mass or less, from the viewpoint of further improvement in thermal and oxidation stability and low sulfur content. More preferably, it is more preferably 10 ppm by mass or less, and particularly preferably 5 ppm by mass or less.

  Further, from the viewpoint of cost reduction, it is preferable to use slack wax or the like as a raw material. In that case, the sulfur content in the obtained lubricating base oil is preferably 50 ppm by mass or less, and preferably 10 ppm by mass or less. More preferred. In addition, the sulfur content as used in the field of this invention means the sulfur content measured based on JISK2541-1996.

  The nitrogen content in the lubricating base oil according to the present invention is not particularly limited, but is preferably 5 ppm by mass or less, more preferably 3 ppm by mass or less, and further preferably 1 ppm by mass or less. If the nitrogen content exceeds 5 ppm by mass, the thermal and oxidation stability tends to decrease. In addition, the nitrogen content as used in the field of this invention means the nitrogen content measured based on JISK2609-1990.

In addition, the kinematic viscosity of the lubricating base oil according to the present invention is not particularly limited as long as the% C _A ,% C _P /% C _N , and iodine value satisfy the above-mentioned conditions, but the kinematic viscosity at 100 ° C. is , Preferably 1.5 to ²⁰ mm ² / s, more preferably 2.0 to 11 mm ² / s. When the kinematic viscosity at 100 ° C. of the lubricating base oil is less than 1.5 mm ² / s, it is not preferable in terms of evaporation loss. In addition, when trying to obtain a lubricating base oil having a kinematic viscosity at 100 ° C. exceeding 20 mm ² / s, the yield decreases, and the decomposition rate can be increased even when heavy wax is used as a raw material. Since it becomes difficult, it is not preferable.

In the present invention, it is preferable to use a lubricating base oil having a kinematic viscosity at 100 ° C. in the following range by distillation or the like.
(I) less than the kinematic viscosity at 100 ° C. is 1.5 mm ² / s or more 3.5 mm ² / s, more preferably kinematic viscosity at 2.0 to 3.0 mm ² / s lubricating base oils (II) 100 ° C. There 3.0 mm ² / s or more 4.5mm less than ² / s, more preferably a kinematic viscosity at 3.5~4.1mm ² / s lubricating base oil (III) 100 ℃ 4.5~20mm ² / s, more preferably 4.8 to 11 mm ² / s, particularly preferably 5.5 to 8.0 mm ² / s.

Moreover, the kinematic viscosity at 40 ° C. of the lubricating base oil according to the present invention is preferably 6.0 to 80 mm ² / s, more preferably 8.0 to 50 mm ² / s. In the present invention, it is preferred that a lubricating oil fraction having a kinematic viscosity at 40 ° C. in the following range is fractionated by distillation or the like and used.
(IV) less than the kinematic viscosity at 40 ° C. is 6.0 mm ² / s or more 12 mm ² / s, more preferably 8.0~12mm ² / s lubricating base oil (V) kinematic viscosity at 40 ° C. is 12 mm ² / More than s and less than 28 mm < ² > / s, more preferably 13-19 mm < ² > / s lubricating base oil (VI) The kinematic viscosity at 40 [deg.] C. is 28-50 mm < ² > / s, more preferably 29-45 mm < ² > / s, particularly preferred. Is a lubricating base oil of 30 to 40 mm ² / s.

The above lubricating base oils (I) and (IV) are compared with conventional lubricating base oils with the same viscosity grade by satisfying the above conditions for% C _A ,% C _P /% C _N and iodine value, respectively. In particular, the low-temperature viscosity characteristics are excellent, and the viscosity resistance and stirring resistance can be remarkably reduced. Moreover, the BF viscosity in -40 degreeC can be 2000 mPa * s or less by mix | blending a pour point depressant. The BF viscosity at −40 ° C. means the viscosity measured according to JPI-5S-26-99.

In addition, the lubricating base oils (II) and (V) described above are conventional lubricating base oils having the same viscosity grade because% C _A ,% C _P /% C _N , and iodine value satisfy the above-mentioned conditions. In particular, it is excellent in low-temperature viscosity characteristics, volatilization prevention properties and lubricity. For example, in the lubricating base oils (II) and (V), the CCS viscosity at −35 ° C. can be set to 3000 mPa · s or less.

In addition, the lubricating base oils (III) and (VI) described above are conventional lubricating base oils having the same viscosity grade because% C _A ,% C _P /% C _N , and iodine value satisfy the above conditions, respectively. Compared with, it is excellent in low temperature viscosity characteristics, volatilization prevention, thermal / oxidation stability and lubricity.

  The viscosity index of the lubricating base oil according to the present invention depends on the viscosity grade of the lubricating base oil, but the viscosity index is 110 or more in any of the lubricating base oils (I) to (VI). be able to. The viscosity index of the lubricating oils (I) and (IV) is preferably 110 to 135, more preferably 115 to 130, and still more preferably 120 to 130. The viscosity index of the lubricating base oils (II) and (V) is preferably 125 to 160, more preferably 130 to 150, and still more preferably 135 to 150. Further, the viscosity index of the lubricating base oils (III) and (VI) is preferably 135 to 180, more preferably 140 to 160. When the viscosity index is less than the lower limit, viscosity-temperature characteristics, thermal / oxidation stability, and further volatilization prevention properties tend to decrease. On the other hand, when the viscosity index exceeds the upper limit, the low-temperature viscosity characteristics tend to decrease.

  In addition, the viscosity index as used in the field of this invention means the viscosity index measured based on JISK2283-1993.

  Further, the refractive index at 20 ° C. of the lubricating base oil according to the present invention depends on the viscosity grade of the lubricating base oil, and for example, the refractive index at 20 ° C. of the lubricating base oils (I) and (IV). Is preferably 1.440 to 1.461, more preferably 1.442 to 1.460, and still more preferably 1.445 to 1.459. The refractive index of the lubricating base oils (II) and (V) at 20 ° C. is preferably 1.450 to 1.465, more preferably 1.452 to 1.463, and still more preferably 1.453 to 1.462. The refractive index of the lubricating base oils (III) and (VI) at 20 ° C. is preferably 1.455 to 1.469, more preferably 1.456 to 1.468, and still more preferably 1.457 to 1.467. If the refractive index exceeds the above upper limit, the viscosity-temperature characteristics and thermal / oxidative stability of the lubricating base oil tend to be reduced, and further, the volatilization preventing properties and low-temperature viscosity characteristics tend to deteriorate. When an additive is blended with the additive, the effectiveness of the additive tends to decrease.

  Further, the pour point of the lubricating base oil according to the present invention depends on the viscosity grade of the lubricating base oil. For example, the pour point of the lubricating base oils (I) and (IV) is preferably −10. ° C or lower, more preferably -12.5 ° C or lower, still more preferably -15 ° C or lower. The pour points of the lubricating base oils (II) and (V) are preferably −10 ° C. or lower, more preferably −15 ° C. or lower, and still more preferably −17.5 ° C. or lower. The pour point of the lubricating base oils (III) and (VI) is preferably −10 ° C. or lower, more preferably −12.5 ° C. or lower, and still more preferably −15 ° C. or lower. When the pour point exceeds the upper limit, the low temperature fluidity of the entire lubricating oil using the lubricating base oil tends to decrease. In addition, the pour point as used in the field of this invention means the pour point measured based on JISK2269-1987.

  Further, the CCS viscosity of the lubricating base oil according to the present invention at −35 ° C. depends on the viscosity grade of the lubricating base oil, but for example, the lubricating base oils (I) and (IV) at −35 ° C. The CCS viscosity is preferably 1000 mPa · s or less. The CCS viscosity at −35 ° C. of the lubricating base oils (II) and (V) is preferably 3000 mPa · s or less, more preferably 2400 mPa · s or less, still more preferably 2200 mPa · s or less, and particularly preferably 2000 mPa · s. -S or less. Further, the CCS viscosity of the lubricating base oils (III) and (VI) at −35 ° C. is preferably 15000 mPa · s or less, more preferably 10000 mPa · s or less, and further preferably 8000 mPa · s or less. When the CCS viscosity at −35 ° C. exceeds the upper limit, the low-temperature fluidity of the entire lubricating oil using the lubricating base oil tends to decrease. In addition, the CCS viscosity at −35 ° C. in the present invention means a viscosity measured according to JIS K 2010-1993.

Further, the density (ρ ₁₅ , unit: g / cm ³ ) of the lubricating base oil according to the present invention at 15 ° C. depends on the viscosity grade of the lubricating base oil, but the value of ρ represented by the following formula (1) It is preferable that ρ ₁₅ ≦ ρ.
ρ = 0.0025 × kv100 + 0.820 (1)
[Wherein, kv100 represents the kinematic viscosity (mm ² / s) of the lubricating base oil at 100 ° C. ]

When ρ ₁₅ > ρ, the viscosity-temperature characteristics and thermal / oxidation stability, volatilization prevention properties and low-temperature viscosity characteristics tend to decrease, and additives are added to the lubricating base oil. In some cases, the effectiveness of the additive tends to decrease.

For example, ρ ₁₅ of the lubricating base oils (I) and (IV) is preferably 0.825 g / cm ³ or less, more preferably 0.820 g / cm ³ or less. The ρ ₁₅ of the lubricating base oils (II) and (V) is preferably 0.835 g / cm ³ or less, more preferably 0.830 g / cm ³ or less. The ρ ₁₅ of the lubricating base oils (III) and (VI) is preferably 0.840 g / cm ³ or less, more preferably 0.835 g / cm ³ or less.

  In addition, the density in 15 degreeC said by this invention means the density measured in 15 degreeC based on JISK2249-1995.

Further, the aniline point (AP (° C.)) of the lubricating base oil according to the present invention depends on the viscosity grade of the lubricating base oil, but is not less than the value of A represented by the following formula (2). It is preferable that ≧ A.
A = 4.1 × kv100 + 97 (2)
[Wherein, kv100 represents the kinematic viscosity (mm ² / s) of the lubricating base oil at 100 ° C. ]

  When AP <A, viscosity-temperature characteristics and thermal / oxidative stability, volatilization prevention properties and low-temperature viscosity characteristics tend to decrease, and when additives are added to the lubricating base oil In addition, the effectiveness of the additive tends to decrease.

  For example, the AP of the lubricating base oils (I) and (IV) is preferably 108 ° C. or higher, more preferably 110 ° C. or higher, and still more preferably 112 ° C. or higher. The AP of the lubricating base oils (II) and (V) is preferably 113 ° C. or higher, more preferably 116 ° C. or higher, still more preferably 118 ° C. or higher, and particularly preferably 120 ° C. or higher. The AP of the lubricating base oils (III) and (VI) is preferably 125 ° C. or higher, more preferably 127 ° C. or higher, and still more preferably 128 ° C. or higher. In addition, the aniline point as used in the field of this invention means the aniline point measured based on JISK2256-1985.

  Further, the NOACK evaporation amount of the lubricating base oil according to the present invention is not particularly limited. For example, the NOACK evaporation amount of the lubricating base oils (I) and (IV) is preferably 20% by mass or more, more preferably. Is 25 mass% or more, more preferably 30 or more, preferably 50 mass% or less, more preferably 45 mass% or less, and still more preferably 42 mass% or less. The NOACK evaporation amount of the lubricating base oils (II) and (V) is preferably 6% by mass or more, more preferably 8% by mass or more, still more preferably 10% by mass or more, and preferably 20%. It is not more than mass%, more preferably not more than 16 mass%, still more preferably not more than 15 mass%, particularly preferably not more than 14 mass%. Further, the NOACK evaporation amount of the lubricating base oils (III) and (VI) is preferably 1% by mass or more, more preferably 2% by mass or more, and preferably 8% by mass or less, more preferably 6%. It is at most 4% by mass, more preferably at most 4% by mass. When the NOACK evaporation amount is the lower limit value, it tends to be difficult to improve the low temperature viscosity characteristics. Further, when the NOACK evaporation amount exceeds the upper limit value, when the lubricating base oil is used as the lubricating oil for an internal combustion engine, the evaporation loss amount of the lubricating oil increases, and accordingly, catalyst poisoning is promoted. Therefore, it is not preferable. In addition, the NOACK evaporation amount as used in the field of this invention means the evaporation loss amount measured based on ASTM D 5800-95.

  Further, the distillation properties of the lubricating base oil according to the present invention are preferably gas chromatography distillation, wherein the initial boiling point (IBP) is 290 to 440 ° C. and the end point (FBP) is 430 to 580 ° C., and such a distillation range. The base oils (I) to (III) and (IV) to (VI) having the preferred viscosity ranges described above are obtained by rectifying one or more fractions selected from the fractions in be able to.

  For example, regarding the distillation properties of the lubricating base oils (I) and (IV), the initial boiling point (IBP) is preferably 260 to 360 ° C, more preferably 300 to 350 ° C, and still more preferably 310 to 350 ° C. It is. Moreover, 10% distillation temperature (T10) becomes like this. Preferably it is 320-400 degreeC, More preferably, it is 340-390 degreeC, More preferably, it is 350-380 degreeC. The 50% distillation point (T50) is preferably 350 to 430 ° C, more preferably 360 to 410 ° C, and still more preferably 370 to 400 ° C. Moreover, 90% distillation point (T90) becomes like this. Preferably it is 380-460 degreeC, More preferably, it is 390-450 degreeC, More preferably, it is 400-440 degreeC. Moreover, an end point (FBP) becomes like this. Preferably it is 420-520 degreeC, More preferably, it is 430-500 degreeC, More preferably, it is 440-480 degreeC. Moreover, T90-T10 becomes like this. Preferably it is 50-100 degreeC, More preferably, it is 55-85 degreeC, More preferably, it is 60-70 degreeC. Moreover, FBP-IBP becomes like this. Preferably it is 100-250 degreeC, More preferably, it is 110-220 degreeC, More preferably, it is 120-200 degreeC. Moreover, T10-IBP becomes like this. Preferably it is 10-80 degreeC, More preferably, it is 15-60 degreeC, More preferably, it is 20-50 degreeC. Moreover, FBP-T90 becomes like this. Preferably it is 10-80 degreeC, More preferably, it is 15-70 degreeC, More preferably, it is 20-60 degreeC.

  Moreover, regarding the distillation properties of the lubricating base oils (II) and (V), the initial boiling point (IBP) is preferably 300 to 380 ° C, more preferably 320 to 370 ° C, still more preferably 330 to 360 ° C. It is. Moreover, 10% distillation temperature (T10) becomes like this. Preferably it is 340-420 degreeC, More preferably, it is 350-410 degreeC, More preferably, it is 360-400 degreeC. The 50% distillation point (T50) is preferably 380 to 460 ° C, more preferably 390 to 450 ° C, and still more preferably 400 to 460 ° C. Moreover, 90% distillation point (T90) becomes like this. Preferably it is 440-500 degreeC, More preferably, it is 450-490 degreeC, More preferably, it is 460-480 degreeC. Moreover, an end point (FBP) becomes like this. Preferably it is 460-540 degreeC, More preferably, it is 470-530 degreeC, More preferably, it is 480-520 degreeC. Moreover, T90-T10 becomes like this. Preferably it is 50-100 degreeC, More preferably, it is 60-95 degreeC, More preferably, it is 80-90 degreeC. Moreover, FBP-IBP becomes like this. Preferably it is 100-250 degreeC, More preferably, it is 120-180 degreeC, More preferably, it is 130-160 degreeC. Moreover, T10-IBP becomes like this. Preferably it is 10-70 degreeC, More preferably, it is 15-60 degreeC, More preferably, it is 20-50 degreeC. Moreover, FBP-T90 becomes like this. Preferably it is 10-50 degreeC, More preferably, it is 20-40 degreeC, More preferably, it is 25-35 degreeC.

  Further, regarding the distillation properties of the lubricating base oils (III) and (VI), the initial boiling point (IBP) is preferably 320 to 480 ° C, more preferably 350 to 460 ° C, still more preferably 380 to 440 ° C. It is. Moreover, 10% distillation temperature (T10) becomes like this. Preferably it is 420-500 degreeC, More preferably, it is 430-480 degreeC, More preferably, it is 440-460 degreeC. The 50% distillation point (T50) is preferably 440 to 520 ° C, more preferably 450 to 510 ° C, and still more preferably 460 to 490 ° C. Moreover, 90% distillation point (T90) becomes like this. Preferably it is 470-550 degreeC, More preferably, it is 480-540 degreeC, More preferably, it is 490-520 degreeC. Moreover, an end point (FBP) becomes like this. Preferably it is 500-580 degreeC, More preferably, it is 510-570 degreeC, More preferably, it is 520-560 degreeC. Moreover, T90-T10 becomes like this. Preferably it is 50-120 degreeC, More preferably, it is 55-100 degreeC, More preferably, it is 55-90 degreeC. Moreover, FBP-IBP becomes like this. Preferably it is 100-250 degreeC, More preferably, it is 110-220 degreeC, More preferably, it is 115-200 degreeC. Moreover, T10-IBP becomes like this. Preferably it is 10-100 degreeC, More preferably, it is 15-90 degreeC, More preferably, it is 20-50 degreeC. Moreover, FBP-T90 becomes like this. Preferably it is 10-50 degreeC, More preferably, it is 20-40 degreeC, More preferably, it is 25-35 degreeC.

  In each of the lubricating base oils (I) to (VI), IBP, T10, T50, T90, FBP, T90-T10, FBP-IBP, T10-IBP, and FBP-T90 are set to the above preferable ranges. Further, it is possible to further improve the low temperature viscosity and further reduce the evaporation loss. In addition, about each of T90-T10, FBP-IBP, T10-IBP, and FBP-T90, when the distillation range is made too narrow, the yield of lubricating base oil is deteriorated, which is not preferable in terms of economy. .

  In the present invention, IBP, T10, T50, T90 and FBP mean distillate points measured in accordance with ASTM D 2887-97, respectively.

  Further, the residual metal content in the lubricating base oil according to the present invention is derived from the metal content contained in the catalyst and raw materials that are inevitably mixed in the manufacturing process, but it is preferable that the residual metal content be sufficiently removed. . For example, the contents of Al, Mo, and Ni are each preferably 1 mass ppm or less. If the content of these metals exceeds the above upper limit, the function of the additive blended with the lubricating base oil tends to be inhibited.

  In addition, the residual metal content as used in the field of this invention means the metal content measured based on JPI-5S-38-2003.

In addition, according to the lubricating base oil of the present invention, excellent thermal / oxidative stability can be achieved by satisfying the above conditions for% C _A ,% C _P /% C _N , and iodine value, respectively. However, it is preferable to show the RBOT life shown below according to the kinematic viscosity. For example, the RBOT life of the lubricating base oils (I) and (IV) is preferably 300 min or more, more preferably 320 min or more, and further preferably 330 min or more. The RBOT life of the lubricating base oils (II) and (V) is preferably 350 min or more, more preferably 370 min or more, and further preferably 380 min or more. The RBOT life of the lubricating base oils (III) and (VI) is preferably 400 min or more, more preferably 410 min or more, and further preferably 420 min or more. When the RBOT life is less than the lower limit, the viscosity-temperature characteristics and thermal / oxidative stability of the lubricating base oil tend to decrease. Further, when an additive is blended in the lubricating base oil, The effectiveness of the additive tends to decrease.

  The RBOT life as used herein refers to a composition in which 0.2% by mass of a phenolic antioxidant (2,6-di-tert-butyl-p-cresol; DBPC) is added to a lubricating base oil. It means the RBOT value measured according to JIS K 2514-1996.

  In the lubricating oil composition for machine tools of the present invention, the lubricating base oil according to the present invention may be used alone, or the lubricating base oil according to the present invention may be one or two of the other base oils. You may use together with a seed or more. When the lubricating base oil according to the present invention is used in combination with another base oil, the ratio of the lubricating base oil according to the present invention in the mixed base oil is preferably 30% by mass or more. More preferably, the content is 50% by mass or more, and further preferably 70% by mass or more.

Although it does not restrict | limit especially as another base oil used together with the lubricating base oil concerning this invention, As a mineral oil type | system | group base oil, solvent refined mineral oil whose kinematic viscosity in 100 degreeC is 1-100 mm < ² > / s, for example, hydrogen Examples include hydrocracked mineral oil, hydrorefined mineral oil, and solvent dewaxing base oil.

  Synthetic base oils include poly α-olefins or hydrides thereof, isobutene oligomers or hydrides thereof, isoparaffins, alkylbenzenes, alkylnaphthalenes, diesters (ditridecyl glutarate, di-2-ethylhexyl adipate, diisodecyl adipate, ditridec Decyl adipate, di-2-ethylhexyl sebacate, etc.), polyol ester (trimethylolpropane caprylate, trimethylolpropane pelargonate, pentaerythritol 2-ethylhexanoate, pentaerythritol pelargonate, etc.), polyoxyalkylene glycol, dialkyl Examples thereof include diphenyl ether and polyphenyl ether, and among them, poly α-olefin is preferable. As the poly α-olefin, typically, an oligomer or co-oligomer (1-octene oligomer, decene oligomer, ethylene-propylene co-oligomer, etc.) having 2 to 32 carbon atoms, preferably 6 to 16 carbon atoms, and those. Of the hydrides.

  The production method of the poly-α-olefin is not particularly limited. For example, Friedel-Crafts catalyst containing a complex of aluminum trichloride or boron trifluoride with water, alcohol (ethanol, propanol, butanol, etc.), carboxylic acid or ester. And a method of polymerizing α-olefin in the presence of a polymerization catalyst such as

  Moreover, the lubricating oil composition for machine tools of this invention contains the compound which contains phosphorus and / or sulfur as a structural element.

  As the compound containing phosphorus as a constituent element (hereinafter referred to as “phosphorus compound”), specifically, phosphate esters such as phosphate monoester, phosphate diester, phosphate triester; phosphorous acid monoester, Phosphites such as phosphite diesters and phosphite triesters; salts of these phosphate esters and phosphites; and mixtures thereof. Moreover, phosphorus-containing carboxylic acid compounds and phosphorothionates can also be used. The phosphorothionate is a compound containing both phosphorus and sulfur as constituent elements. In the following description, “phosphorus compound” includes phosphorothionate.

  The above-described phosphate esters and phosphites are compounds containing a hydrocarbon group usually having 2 to 30 carbon atoms, preferably 3 to 20 carbon atoms. Specific examples of the hydrocarbon group having 2 to 30 carbon atoms include ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, and dodecyl. Group, tridecyl group, tetradecyl group, pentadecyl group, hexadecyl group, heptadecyl group, octadecyl group, etc. (these alkyl groups may be linear or branched); butenyl group, pentenyl group, hexenyl group, heptenyl group Alkenyl groups such as octenyl group, nonenyl group, decenyl group, undecenyl group, dodecenyl group, tridecenyl group, tetradecenyl group, pentadecenyl group, hexadecenyl group, heptadecenyl group, octadecenyl group (these alkenyl groups may be linear or branched) Good, and the position of the double bond is arbitrary); C5-C7 cycloalkyl group such as pentyl group, cyclohexyl group, cycloheptyl group; methylcyclopentyl group, dimethylcyclopentyl group, methylethylcyclopentyl group, diethylcyclopentyl group, methylcyclohexyl group, dimethylcyclohexyl group, methylethylcyclohexyl group Alkylcycloalkyl groups having 6 to 11 carbon atoms such as diethylcyclohexyl group, methylcycloheptyl group, dimethylcycloheptyl group, methylethylcycloheptyl group, and diethylcycloheptyl group (the substitution position of the alkyl group to the cycloalkyl group is also arbitrary) Aryl groups such as phenyl group and naphthyl group: tolyl group, xylyl group, ethylphenyl group, propylphenyl group, butylphenyl group, pentylphenyl group, hexylphenyl group, heptyl Each alkylaryl group having 7 to 18 carbon atoms such as an phenyl group, an octylphenyl group, a nonylphenyl group, a decylphenyl group, an undecylphenyl group, a dodecylphenyl group (the alkyl group may be linear or branched, The substitution position on the aryl group is also arbitrary); each arylalkyl group having 7 to 12 carbon atoms such as benzyl group, phenylethyl group, phenylpropyl group, phenylbutyl group, phenylpentyl group, phenylhexyl group (these alkyl groups) May be linear or branched).

  Preferred examples of phosphate esters and phosphite esters include monoalkyl phosphates such as monopropyl phosphate, monobutyl phosphate, monopentyl phosphate, monohexyl phosphate, monopeptyl phosphate, monooctyl phosphate (alkyl group). May be linear or branched); mono (alkyl) aryl esters of phosphoric acid such as monophenyl phosphate, monocresyl phosphate; dipropyl phosphate, dibutyl phosphate, dipentyl phosphate, dihexyl phosphate, dipeptyl phosphate, dioctyl Dialkyl phosphates such as phosphates (the alkyl group may be linear or branched); di (alkyl) aryl phosphates such as diphenyl phosphate and dicresyl phosphate Steal; Tripropyl phosphate, tributyl phosphate, tripentyl phosphate, trihexyl phosphate, tripeptyl phosphate, trioctyl phosphate, etc. phosphoric acid trialkyl ester (the alkyl group may be linear or branched); triphenyl phosphate Tri (alkyl) aryl esters of phosphate such as tricresyl phosphate; phosphorous such as monopropyl phosphite, monobutyl phosphite, monopentyl phosphite, monohexyl phosphite, monopeptyl phosphite, monooctyl phosphite Acid monoalkyl ester (the alkyl group may be linear or branched); mono (alkyl) aryl phosphite such as monophenyl phosphite and monocresyl phosphite; Dialkyl phosphites such as diphenyl phosphite, dipentyl phosphite, dihexyl phosphite, dipeptyl phosphite and dioctyl phosphite (the alkyl group may be linear or branched); Phosphorous acid di (alkyl) aryl esters such as phosphite; tripropyl phosphite, tributyl phosphite, tripentyl phosphite, trihexyl phosphite, tripeptyl phosphite, trioctyl phosphite Alkyl esters (the alkyl group may be linear or branched); tri (alkyl) aryl phosphites such as triphenyl phosphite and tricresyl phosphite; and mixtures thereof.

  Specific examples of the salts of the phosphoric acid esters and phosphite esters described above include phosphoric acid monoesters, phosphoric acid diesters, phosphorous acid monoesters, phosphorous acid diester esters, ammonia, carbon Examples include salts obtained by allowing a nitrogen-containing compound such as an amine compound containing only a hydrocarbon group of 1 to 8 or a hydroxyl group-containing hydrocarbon group in the molecule to act to neutralize part or all of the remaining acidic hydrogen. It is done.

  Specific examples of the nitrogen-containing compound include ammonia; monomethylamine, monoethylamine, monopropylamine, monobutylamine, monopentylamine, monohexylamine, monoheptylamine, monooctylamine, dimethylamine, methylethylamine, Alkylamines such as diethylamine, methylpropylamine, ethylpropylamine, dipropylamine, methylbutylamine, ethylbutylamine, propylbutylamine, dibutylamine, dipentylamine, dihexylamine, diheptylamine, dioctylamine, etc. May be branched); monomethanolamine, monoethanolamine, monopropanolamine, monobutanolamine, monopentanolamine, monohexanolamine , Monoheptanolamine, monooctanolamine, monononanolamine, dimethanolamine, methanolethanolamine, diethanolamine, methanolpropanolamine, ethanolpropanolamine, dipropanolamine, methanolbutanolamine, ethanolbutanolamine, propanolbutanolamine, dibutanol And alkanolamines such as amines, dipentanolamines, dihexanolamines, diheptanolamines, dioctanolamines (the alkanol groups may be linear or branched); and mixtures thereof.

  When using the above-mentioned phosphate esters or phosphites, the content is preferably 10% by mass or less, more preferably 5% by mass or less, and still more preferably 3% by mass or less, based on the total amount of the composition. is there. Even if the content exceeds 5% by mass, no further improvement in wear resistance and frictional properties commensurate with the content is observed, and oxidation stability decreases, which is not preferable. On the other hand, the content of phosphate esters and phosphites is preferably 0.01% by mass or more, more preferably 0.05% by mass or more, and still more preferably 0.1% by mass, based on the total amount of the composition. That's it. When the content of phosphates and phosphites is less than 0.01% by mass, the effect of improving the wear resistance and frictional properties due to the addition tends to be insufficient.

  The phosphorus-containing carboxylic acid compound is not particularly limited as long as it contains both a carboxyl group and a phosphorus atom in the same molecule. However, phosphorylated carboxylic acids are preferred from the viewpoints of wear resistance and heat / oxidation stability.

  Examples of the phosphorylated carboxylic acid include compounds represented by the following general formula (4).

［式（４）中、Ｒ^１及びＲ^２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の炭化水素基を示し、Ｒ^３は炭素数１〜２０のアルキレン基を示し、Ｒ^４は水素原子又は炭素数１〜３０の炭化水素基を示し、Ｘ^１、Ｘ^２、Ｘ^３及びＸ^４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示す。］

[In Formula (4), R ¹ and R ² may be the same or different, and each represents a hydrogen atom or a hydrocarbon group having 1 to 30 carbon atoms, and R ³ represents an alkylene group having 1 to 20 carbon atoms. , R ⁴ represents a hydrogen atom or a hydrocarbon group having 1 to 30 carbon atoms, and X ¹ , X ² , X ³ and X ⁴ may be the same or different and each represents an oxygen atom or a sulfur atom. ]

In General Formula (4), R ¹ and R ² each represent a hydrogen atom or a hydrocarbon group having 1 to 30 carbon atoms. Examples of the hydrocarbon group having 1 to 30 carbon atoms include an alkyl group, an alkenyl group, a cycloalkyl group, a bicycloalkyl group, a tricycloalkyl group, an alkylcycloalkyl group, an alkylbicycloalkyl group, an alkyltricycloalkyl group, and a cycloalkylalkyl. Group, bicycloalkylalkyl group, tricycloalkylalkyl group, aryl group, alkylaryl group, arylalkyl group and the like. R ¹ and R ² may be bonded to form a divalent group represented by the following general formula (5). The two bonds of the divalent group are bonded to X ¹ and X ² , respectively.

［式（５）中、Ｒ^５及びＲ^６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１〜４のアルキル基を示し、Ｒ^５及びＲ^６の双方がメチル基であることが好ましい。］

[In Formula (5), R ⁵ and R ⁶ may be the same or different and each represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and both R ⁵ and R ⁶ are methyl groups. preferable. ]

R ¹ and R ² are, among these, an alkyl group, a cycloalkyl group, a cycloalkylalkyl group, a tricycloalkylalkyl group, an aryl group, an alkylaryl group, and the above general formula (5) in which R ¹ and R ² are bonded. ) Is preferably a divalent group, and more preferably an alkyl group.

The alkyl group as R ¹ and R ² may be linear or branched. The alkyl group preferably has 1 to 18 carbon atoms. Specific examples of such an alkyl group include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tertiary butyl group, a pentyl group, an isopentyl group, a hexyl group, and a heptyl group. 3-heptyl group, octyl group, 2-ethylhexyl group, nonyl group, decyl group, undecyl group, dodecyl group, tridecyl group, tetradecyl group, pentadecyl group, hexadecyl group, heptadecyl group, octadecyl group, 2-ethylbutyl group, 1 -Methylphenyl group, 1,3-dimethylbutyl group, 1,1,3,3-tetramethylbutyl group, 1-methylhexyl group, isoheptyl group, 1-methylheptyl group, 1,1,3-trimethylhexyl group And 1-methylundecyl group. Among these, a C3-C18 alkyl group is preferable and a C3-C8 alkyl group is more preferable.

Examples of the cycloalkyl group as R ¹ and R ² include a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, and a cyclododecyl group. Among these, a cycloalkyl group having 5 or 6 carbon atoms (cyclopentyl group and cyclohexyl group) is preferable, and a cyclohexyl group is particularly preferable.

The cycloalkylalkyl group as R ¹ and R ² is preferably a cycloalkylmethyl group, more preferably a cycloalkylmethyl group having 6 or 7 carbon atoms, and particularly preferably a cyclopentylmethyl group and a cyclohexylmethyl group.

As the bicycloalkylalkyl group as R ¹ and R ² , a bicycloalkylmethyl group is preferable, a bicycloalkylmethyl group having 9 to 11 carbon atoms is more preferable, and a decalinylmethyl group is particularly preferable.

The tricycloalkylalkyl group as R ¹ and R ² is preferably a tricycloalkylmethyl group, more preferably a tricycloalkylmethyl group having 9 to 15 carbon atoms, represented by the following formula (6) or (7). Particularly preferred are the groups

As the aryl group and alkylaryl group as R ¹ and R ² , phenyl group, tolyl group, xylyl group, ethylphenyl group, vinylphenyl group, methylphenyl group, dimethylphenyl group, trimethylphenyl group, ethylphenyl group, isopropyl Examples thereof include a phenyl group, a tert-butylphenyl group, a di-tert-butylphenyl group, and a 2,6-di-tert-butyl-4-methylphenyl group. Among these, an aryl group having 6 to 15 carbon atoms and an alkylaryl group are preferable.

R ³ represents an alkylene group having 1 to 20 carbon atoms. The number of carbon atoms of the alkylene group is preferably 1 to 10, more preferably 2 to 6, and further preferably 3 to 4. Moreover, as such an alkylene group, what is represented by following General formula (8) is preferable.

In the general formula (8), R ⁷ , R ⁸ , R ⁹ and R ¹⁰ may be the same or different, and each represents a hydrogen atom or a hydrocarbon group having 1 to 4 carbon atoms, and R ⁷ , R ⁸ , R The total number of carbon atoms of ⁹ and R ¹⁰ is 6 or less. Preferably, R ⁷ , R ⁸ , R ⁹ and R ¹⁰ may be the same or different and each represents a hydrogen atom or a hydrocarbon group having 1 to 3 carbon atoms, and R ⁷ , R ⁸ , R ⁹ and The total number of carbon atoms of R ¹⁰ is 5 or less. More preferably, R ⁷ , R ⁸ , R ⁹ and R ¹⁰ may be the same or different and each represents a hydrogen atom or a hydrocarbon group having 1 or 2 carbon atoms, and R ⁷ , R ⁸ , R ⁹ and R 10 The total of ¹⁰ carbon atoms is 4 or less. Particularly preferably, R ⁷ , R ⁸ , R ⁹ and R ¹⁰ may be the same or different and each represents a hydrogen atom or a hydrocarbon group having 1 to 2 carbon atoms, and R ⁷ , R ⁸ , R ⁹ and R 10 The total of ¹⁰ carbon atoms is 3 or less. Most preferably, either R ⁹ or R ¹⁰ is a methyl group and the remaining three groups are hydrogen atoms.

In general formula (4) ^{R 4} in the show a hydrogen atom or a hydrocarbon group having 1 to 30 carbon atoms. Examples of the hydrocarbon group include the hydrocarbon groups exemplified in the description of R ¹ and R ² .
Further, X ¹ , X ² , X ³ and X ⁴ in the general formula (4) may be the same or different and each represents an oxygen atom or a sulfur atom. From the point of extreme pressure, one or more of X ¹ , X ² , X ³ or X ⁴ are preferably sulfur atoms, more preferably two or more are sulfur atoms, and two are sulfur atoms. More preferably, the remaining two are oxygen atoms. In this case, it is arbitrary which of X ¹ , X ² , X ³ or X ⁴ is a sulfur atom, but X ¹ and X ² are oxygen atoms, and X ³ and X ⁴ are sulfur atoms. It is preferable.

  As mentioned above, although each group in General formula (4) was demonstrated, since it is excellent in extreme pressure property, (beta) -dithio phosphorylated propionic acid represented by following General formula (9) is used preferably.

［式（９）中、Ｒ^１、Ｒ^２はそれぞれ式（１）中のＲ^１、Ｒ^２と同一の定義内容を示し、Ｒ^７、Ｒ^８、Ｒ^９、Ｒ^１０はそれぞれ（８）中のＲ^７、Ｒ^８、Ｒ^９、Ｒ^１０と同一の定義内容を示す。］

Wherein ^(9), R 1, ^{R 2} represents a ^R 1, ^{R 2} identical definitions and their respective formulas ^{(1), R 7, R 8, R} 9, R 10 are each (8) in The same definition content as R ⁷ , R ⁸ , R ⁹ , and R ¹⁰ is shown. ]

When the above phosphorus-containing carboxylic acid compound is used, the content is not particularly limited, but is preferably 0.001 to 5% by mass, more preferably 0.002 to 3% by mass, and still more preferably based on the total amount of the composition. 0.003 to 1% by mass. When the content of the phosphorus-containing carboxylic acid compound is less than the lower limit, the effect of improving the wear resistance and frictional properties due to the addition tends to be insufficient. On the other hand, even if the upper limit is exceeded, there is a tendency that an effect of improving lubricity commensurate with the content tends not to be obtained, and furthermore, heat / oxidation stability and hydrolysis stability may be lowered. In addition, among the phosphorylated carboxylic acids represented by the general formula (4), the compound containing R ⁴ is a hydrogen atom (including β-dithiophosphorylated propionic acid represented by the general formula (9)). The amount is preferably 0.001 to 0.1% by mass, more preferably 0.002 to 0.08% by mass, still more preferably 0.003 to 0.07% by mass, and still more preferably 0.004 to 0%. 0.06% by mass, particularly preferably 0.005 to 0.05% by mass. If the content is less than 0.001, the effect of improving extreme pressure may be insufficient. On the other hand, if the content exceeds 0.1% by mass, the heat / oxidation stability may be lowered.

  Moreover, phosphorothionate is a compound represented by the following general formula (10).

［式中、Ｒ^１１〜Ｒ^１３は同一でも異なっていてもよく、それぞれ炭素数１〜２４の炭化水素基を示す。］

[Wherein, R ^{11 to} R ¹³ may be the same or different and each represents a hydrocarbon group having 1 to 24 carbon atoms. ]

Specific examples of the hydrocarbon group having 1 to 24 carbon atoms represented by R ^{11 to} R ¹³ include an alkyl group, a cycloalkyl group, an alkenyl group, an alkylcycloalkyl group, an aryl group, an alkylaryl group, and an arylalkyl group. Etc.

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

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

  As an 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 (these alkyl groups may be linear or branched). May be branched).

Hydrocarbon group of 1 to 24 carbon atoms represented by the ^R 11 ^{to R 13} is an alkyl group, an aryl group, preferably an alkyl aryl group, an alkyl group having 4 to 18 carbon atoms, having 7 to 24 carbon atoms An alkylaryl group and a phenyl group are more preferable.

  Specific examples of the phosphorothioate represented by the general formula (10) include tributyl phosphorothioate, tripentyl phosphorothioate, trihexyl phosphorothioate, triheptyl phosphorothionate, and trioctyl. Phosphorothioate, trinonyl phosphorothionate, tridecyl phosphorothionate, triundecyl phosphorothionate, tridodecyl phosphorothionate, tritridecyl phosphorothionate, tritetradecyl phosphorothionate, tri Pentadecyl phosphorothioate, trihexadecyl phosphorothionate, triheptadecyl phosphorothionate, trioctadecyl phosphorothionate, trioleyl phosphorothionate, triphenyl phosphorothionate, triphenyl Resyl phosphorothioate, trixylenyl phosphorothioate, cresyl diphenyl phosphorothioate, xylenyl diphenyl phosphorothioate, tris (n-propylphenyl) phosphorothionate, tris (isopropylphenyl) phos Forothionate, tris (n-butylphenyl) phosphorothionate, tris (isobutylphenyl) phosphorothionate, tris (s-butylphenyl) phosphorothionate, tris (t-butylphenyl) phosphorothionate, etc. . Mixtures of these can also be used.

  When the above phosphorothionate is used, the content is not particularly limited, but is preferably 0.001 to 10% by mass, more preferably 0.005 to 5% by mass, and still more preferably 0, based on the total amount of the composition. 0.01 to 3% by mass. Even if the content of the phosphorothionate exceeds the above upper limit, no further improvement in wear resistance and frictional properties commensurate with the content is observed, and oxidation stability is lowered, which is not preferable. On the other hand, the phosphorothioate content is preferably 0.01% by mass or more, more preferably 0.05% by mass or more, and further preferably 0.1% by mass or more, based on the total amount of the composition. When the content of the phosphorothioate is less than 0.01% by mass, the effect of improving the wear resistance and frictional properties due to the addition tends to be insufficient.

  Specific examples of compounds containing sulfur as a constituent element (hereinafter referred to as “sulfur compounds”) include sulfurized fats and oils, sulfurized fatty acids, sulfurized esters, sulfurized olefins, dihydrocarbyl (poly) sulfide, thiadiazole compounds, alkylthiocarbamoyl. Examples thereof include compounds, thiocarbamate compounds, thioterpene compounds, dialkylthiodipropionate compounds, sulfide mineral oil, zinc dithiocarbamate compounds and molybdenum dithiocarbamates. These sulfur compounds may be used alone or as a mixture of two or more. In addition, although the zinc dithiophosphate compound and the molybdenum dithiophosphate compound are compounds containing both phosphorus and sulfur as constituent elements, the zinc dithiophosphate compound and the molybdenum dithiophosphate compound are included in the “sulfur compound” in the following description. Shall.

  Sulfurized fats and oils are obtained by reacting sulfur and sulfur-containing compounds with fats and oils (lard oil, whale oil, vegetable oil, fish oil, etc.), and the sulfur content is not particularly limited, but is generally 5 to 30% by mass. Those are preferred. Specific examples thereof include sulfurized lard, sulfurized rapeseed oil, sulfurized castor oil, sulfurized soybean oil, sulfurized rice bran oil, and mixtures thereof.

  Examples of sulfurized fatty acids include sulfurized oleic acid, and examples of sulfurized esters include reaction of unsaturated fatty acids (including oleic acid, linoleic acid, or fatty acids extracted from the above-mentioned animal and vegetable oils) and various alcohols. And the like obtained by sulfiding the unsaturated fatty acid ester obtained by mixing with an arbitrary method, specifically, for example, methyl sulfide oleate, sulfurized rice bran fatty acid octyl, and a mixture thereof. Can be mentioned.

  Examples of the sulfurized olefin include compounds represented by the following general formula (11).

This compound is obtained by reacting an olefin having 2 to 15 carbon atoms or a dimer to tetramer thereof with a sulfurizing agent such as sulfur or sulfur chloride, and propylene, isobutene, diisobutene and the like are preferable.
R ¹⁴ -S _a -R ¹⁵ (11)
[Wherein, R ¹⁴ represents an alkenyl group having 2 to ¹⁵ carbon atoms, R ¹⁵ represents an alkyl group or alkenyl group having 2 to ¹⁵ carbon atoms, and a represents an integer of 1 to 8. ]

Dihydrocarbyl (poly) sulfide is a compound represented by the following general formula (12). Here, when R ²⁹ and R ³⁰ are alkyl groups, they may be referred to as alkyl sulfides.
R ¹⁶ -S _b -R ¹⁷ (12)
[Wherein, R ¹⁶ and R ¹⁷ may be the same or different and each represents a chain alkyl group having 1 to 20 carbon atoms, a branched or cyclic alkyl group, an aryl group having 6 to 20 carbon atoms, or 7 carbon atoms. Represents an alkylaryl group of -20 or an arylalkyl group of 7-20 carbon atoms, and b represents an integer of 1-8. ]

Specific examples of R ¹⁶ and R ¹⁷ in the general formula (12) include n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group, straight chain 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 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 or branched nonadecyl group, linear or branched alkyl group such as linear or branched icosyl group; aryl group such as phenyl group or naphthyl group; tolyl group ( All structural isomers Including), ethylphenyl group (including all structural isomers), linear or branched propylphenyl group (including all structural isomers), linear or branched butylphenyl group (including all structural isomers) ), Straight chain or branched pentylphenyl group (including all structural isomers), straight chain or branched hexylphenyl group (including all structural isomers), straight chain or branched heptylphenyl group (all structures) Isomers), linear or branched octylphenyl groups (including all structural isomers), linear or branched nonylphenyl groups (including all structural isomers), linear or branched decylphenyl groups (Including all structural isomers), linear or branched undecylphenyl group (including all structural isomers), linear or branched dodecylphenyl group (including all structural isomers), xylyl group (including all structural isomers) Including all structural isomers), Ethylmethylphenyl group (including all structural isomers), diethylphenyl group (including all structural isomers), di (straight or branched) propylphenyl group (including all structural isomers), di ( Linear or branched) butylphenyl group (including all structural isomers), methyl naphthyl group (including all structural isomers), ethyl naphthyl group (including all structural isomers), linear or branched Propyl naphthyl group (including all structural isomers), linear or branched butyl naphthyl group (including all structural isomers), dimethyl naphthyl group (including all structural isomers), ethyl methyl naphthyl group (all ), Diethyl naphthyl group (including all structural isomers), di (linear or branched) propyl naphthyl group (including all structural isomers), di (linear or branched) Butylnaphthyl group ( Alkylaryl groups such as all structural isomers; arylalkyl groups such as benzyl, phenylethyl groups (including all isomers), phenylpropyl groups (including all isomers), etc. Can do. Among these, as R < ¹⁶ > and R < ¹⁷ > in General formula (12), a C3-C18 alkyl group derived from propylene, 1-butene, or isobutylene, or a C6-C8 aryl group, alkyl An aryl group or an arylalkyl group is preferable. Examples of these groups include isopropyl group, branched hexyl group derived from propylene dimer (including all branched isomers), and propylene trimer. Branched nonyl groups derived from the body (including all branched isomers), branched dodecyl groups derived from the propylene tetramer (including all branched isomers), 5 quantities of propylene Branched pentadecyl groups derived from the body (including all branched isomers), branched octadecyl groups derived from the propylene hexamer (including all branched isomers), ec-butyl group, tert-butyl group, branched octyl group derived from 1-butene dimer (including all branched isomers), branched octyl group derived from isobutylene dimer (Including all branched isomers), branched dodecyl group derived from 1-butene trimer (including all branched isomers), branched derived from isobutylene trimer Dodecyl group (including all branched isomers), branched hexadecyl group (including all branched isomers) derived from 1-butene tetramer, fraction derived from isobutylene tetramer Alkyl groups such as branched hexadecyl groups (including all branched isomers); phenyl groups, tolyl groups (including all structural isomers), ethylphenyl groups (including all structural isomers), xylyl groups Alkyl compounds such as (including all structural isomers) Examples include a reel group; arylalkyl groups such as benzyl group and phenylethyl group (including all isomers).

Furthermore, R ¹⁶ and R ¹⁷ in the general formula (12) are each independently a branched alkyl having 3 to 18 carbon atoms derived from ethylene or propylene, from the viewpoint of improvement in wear resistance and friction characteristics. More preferably, it is a branched alkyl group having 6 to 15 carbon atoms derived from ethylene or propylene.

  Examples of the dihydrocarbyl (poly) sulfide represented by the general formula (12) include dibenzyl polysulfide, various dinonyl polysulfides, various didodecyl polysulfides, various dibutyl polysulfides, various dioctyl polysulfides, diphenyl polysulfide, dicyclohexyl polysulfide, and these. A mixture etc. can be mentioned preferably.

  Examples of the thiadiazole compound include 1,3,4-thiadiazole represented by the following general formula (13), 1,2,4-thiadiazole compound represented by the following general formula (14), and the following general formula (15). The 1,4,5-thiadiazole compound represented by these is mentioned.

［式中、Ｒ^１８、Ｒ^１９、Ｒ^２０、Ｒ^２１、Ｒ^２２及びＲ^２３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１〜２０の炭化水素基を示し、ｃ、ｄ、ｅ、ｆ、ｇ及びｈは同一でも異なっていてもよく、それぞれ０〜８の整数を示す］

[Wherein R ¹⁸ , R ¹⁹ , R ²⁰ , R ²¹ , R ²² and R ²³ may be the same or different and each represents a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms, c, d, e, f, g and h may be the same or different and each represents an integer of 0 to 8]

  Specific examples of such thiadiazole compounds include 2,5-bis (n-hexyldithio) -1,3,4-thiadiazole, 2,5-bis (n-octyldithio) -1,3,4-thiadiazole. 2,5-bis (n-nonyldithio) -1,3,4-thiadiazole, 2,5-bis (1,1,3,3-tetramethylbutyldithio) -1,3,4-thiadiazole, 3, 5-bis (n-hexyldithio) -1,2,4-thiadiazole, 3,5-bis (n-octyldithio) -1,2,4-thiadiazole, 3,5-bis (n-nonyldithio) -1 , 2,4-thiadiazole, 3,5-bis (1,1,3,3-tetramethylbutyldithio) -1,2,4-thiadiazole, 4,5-bis (n-hexyldithio) -1,2 , 3-thiadiazole, 4 5-bis (n-octyldithio) -1,2,3-thiadiazole, 4,5-bis (n-nonyldithio) -1,2,3-thiadiazole, 4,5-bis (1,1,3,3) Preferred examples include -tetramethylbutyldithio) -1,2,3-thiadiazole and a mixture thereof.

  Examples of the alkylthiocarbamoyl compound include a compound represented by the following general formula (16).

［式中、Ｒ^２４〜Ｒ^２７は同一でも異なっていてもよく、それぞれ炭素数１〜２０のアルキル基を示し、ｋは１〜８の整数を示す。］

[Wherein, R ^{24 to} R ²⁷ may be the same or different and each represents an alkyl group having 1 to 20 carbon atoms, and k represents an integer of 1 to 8. ]

Specific examples of such alkylthiocarbamoyl compounds include bis (dimethylthiocarbamoyl) monosulfide, bis (dibutylthiocarbamoyl) monosulfide, bis (dimethylthiocarbamoyl) disulfide, bis (dibutylthiocarbamoyl) disulfide, and bis (diamil). Preferred examples include thiocarbamoyl) disulfide, bis (dioctylthiocarbamoyl) disulfide, and mixtures thereof.
Examples of the alkylthiocarbamate compound include a compound represented by the following general formula (17).

［式中、Ｒ^２８〜Ｒ^３１は同一でも異なっていてもよく、それぞれ炭素数１〜２０のアルキル基を示し、Ｒ^３２は炭素数１〜１０のアルキル基を示す。］

[Wherein, R ^{28 to} R ³¹ may be the same or different and each represents an alkyl group having 1 to 20 carbon atoms, and R ³² represents an alkyl group having 1 to 10 carbon atoms. ]

  Preferable examples of such alkylthiocarbamate compounds include methylenebis (dibutyldithiocarbamate), methylenebis [di (2-ethylhexyl) dithiocarbamate] and the like.

Further, examples of the thioterpene compound include a reaction product of phosphorus pentasulfide and pinene, and examples of the dialkylthiodipropionate compound include dilauryl thiodipropionate, distearyl thiodipropionate, and a mixture thereof. be able to.
Sulfided mineral oil refers to one obtained by dissolving elemental sulfur in mineral oil. Here, the mineral oil used in the sulfide mineral oil according to the present invention is not particularly limited. Specifically, specifically, a lubricating oil fraction obtained by subjecting crude oil to atmospheric distillation and vacuum distillation is used as a solvent. Examples thereof include paraffinic mineral oil, naphthenic mineral oil, and the like, which are refined by appropriately combining purification treatments such as deblocking, solvent extraction, hydrocracking, solvent dewaxing, catalytic dewaxing, hydrorefining, sulfuric acid washing, and clay treatment. In addition, as the elemental sulfur, any form such as a lump, powder, molten liquid, etc. may be used, but when powdered or molten liquid elemental sulfur is used, it is efficiently dissolved in the base oil. Is preferable. In addition, molten liquid elemental sulfur has the advantage that the melting operation can be performed in a very short time because the liquids are mixed together, but it must be handled above the melting point of elemental sulfur, heating equipment, etc. It is not always easy to handle because it requires special equipment and is handled in a high temperature atmosphere. On the other hand, powdery simple sulfur is particularly preferable because it is inexpensive and easy to handle, and the time required for dissolution is sufficiently short. Moreover, although there is no restriction | limiting in particular in the sulfur content in the sulfide mineral oil concerning this invention, Preferably it is 0.05-1.0 mass% normally on the basis of the sulfide mineral oil whole quantity, More preferably, it is 0.1-0. 5% by mass.

  The zinc dithiophosphate compound, zinc dithiocarbamate compound, molybdenum dithiophosphate compound and molybdenum dithiocarbamate compound mean compounds represented by the following general formulas (18) to (21), respectively.

［式中、Ｒ^３３、Ｒ^３４、Ｒ^３５、Ｒ^３６、Ｒ^３７、Ｒ^３８、Ｒ^３９、Ｒ^４０、Ｒ^４１、Ｒ^４２、Ｒ^４３、Ｒ^４４、Ｒ^４５、Ｒ^４６、Ｒ^４７及びＲ^４８は同一でも異なっていてもよく、それぞれ炭素数１以上の炭化水素基を表し、Ｘ^１及びＸ^２はそれぞれ酸素原子又は硫黄原子を表す］

[Wherein R ³³ , R ³⁴ , R ³⁵ , R ³⁶ , R ³⁷ , R ³⁸ , R ³⁹ , R ⁴⁰ , R ⁴¹ , R ⁴² , R ⁴³ , R ⁴⁴ , R ⁴⁵ , R ⁴⁶ , R ⁴⁷ and R ⁴⁸ may be the same or different, each represents a hydrocarbon group having 1 or more carbon atoms, and X ¹ and X ² each represent an oxygen atom or a sulfur atom]

Here, specific examples of the hydrocarbon group represented by R ^{33 to} R ⁴⁸ are exemplified by methyl group, ethyl group, propyl group (including all branched isomers), butyl group (all branched isomers). ), Pentyl groups (including all branched isomers), hexyl groups (including all branched isomers), heptyl groups (including all branched isomers), octyl groups (including all branched isomers) Branch isomers), nonyl groups (including all branch isomers), decyl groups (including all branch isomers), undecyl groups (including all branch isomers), dodecyl groups (all ), Tridecyl group (including all branched isomers), tetradecyl group (including all branched isomers), pentadecyl group (including all branched isomers), hexadecyl group (Including all branched isomers), heptadeci Groups (including all branched isomers), octadecyl groups (including all branched isomers), nonadecyl groups (including all branched isomers), icosyl groups (including all branched isomers) , Heicosyl group (including all branched isomers), docosyl group (including all branched isomers), tricosyl group (including all branched isomers), tetracosyl group (including all branched isomers) Alkyl groups such as cyclopentyl group, cyclohexyl group and cycloheptyl group; methylcyclopentyl group (including all substituted isomers), ethylcyclopentyl group (including all substituted isomers), dimethylcyclopentyl Groups (including all substituted isomers), propylcyclopentyl groups (including all branched and substituted isomers), methylethylcyclope Til group (including all substituted isomers), trimethylcyclopentyl group (including all substituted isomers), butylcyclopentyl group (including all branched and substituted isomers), methylpropylcyclopentyl group (all Branched isomers, including substituted isomers, diethylcyclopentyl group (including all substituted isomers), dimethylethylcyclopentyl group (including all substituted isomers), methylcyclohexyl group (including all substituted isomers) ), Ethylcyclohexyl group (including all substituted isomers), dimethylcyclohexyl group (including all substituted isomers), propylcyclohexyl group (including all branched isomers and substituted isomers), methylethylcyclohexyl group (Including all substituted isomers), trimethylcyclohexyl group (all substituted isomers) Butyl cyclohexyl group (including all branched and substituted isomers), methylpropyl cyclohexyl group (including all branched and substituted isomers), diethyl cyclohexyl group (including all substituted isomers) Isomers), dimethylethylcyclohexyl group (including all substituted isomers), methylcycloheptyl group (including all substituted isomers), ethylcycloheptyl group (including all substituted isomers), dimethylcyclohexane Heptyl group (including all substituted isomers), propylcycloheptyl group (including all branched isomers and substituted isomers), methylethylcycloheptyl group (including all substituted isomers), trimethylcycloheptyl group (Including all substituted isomers), butylcycloheptyl group (including all branched isomers, substituted isomers), Tilpropylcycloheptyl group (including all branched and substituted isomers), diethylcycloheptyl group (including all substituted isomers), dimethylethylcycloheptyl group (including all substituted isomers), etc. Alkylcycloalkyl groups; aryl groups such as phenyl and naphthyl groups; tolyl groups (including all substituted isomers), xylyl groups (including all substituted isomers), ethylphenyl groups (including all substituted isomers) ), Propylphenyl group (including all branched and substituted isomers), methylethylphenyl group (including all substituted isomers), trimethylphenyl group (including all substituted isomers), butylphenyl group (Including all branched isomers and substituted isomers), methylpropylphenyl group (including all branched isomers and substituted isomers), Ethylphenyl group (including all substituted isomers), dimethylethylphenyl group (including all substituted isomers), pentylphenyl group (including all branched and substituted isomers), hexylphenyl group (all Branched isomers, including substituted isomers), heptylphenyl group (including all branched isomers, including substituted isomers), octylphenyl group (including all branched isomers, including substituted isomers), nonyl Phenyl group (all branched isomers, including substituted isomers), decylphenyl group (including all branched isomers, substituted isomers), undecylphenyl group (all branched isomers, substituted isomers) ), Dodecylphenyl group (including all branched and substituted isomers), tridecylphenyl group (including all branched and substituted isomers), tetradecylphenyl group (including All branched isomers, including substituted isomers), pentadecylphenyl group (including all branched isomers, including substituted isomers), hexadecylphenyl group (including all branched isomers, substituted isomers) Alkylaryl groups such as heptadecylphenyl group (including all branched isomers and substituted isomers), octadecylphenyl group (including all branched isomers and substituted isomers); benzyl group, phenethyl group Arylalkyl groups such as phenylpropyl group (including all branched isomers), phenylbutyl group (including all branched isomers), and the like.

  When using the above sulfur compound, the content is preferably 0.01% by mass or more, more preferably 0.05% by mass or more, and further preferably 0.1% by mass or more, based on the total amount of the composition. When the content of the sulfur compound is less than the lower limit, the effect of improving the wear resistance and frictional properties due to the addition tends to be insufficient. In addition, the content of the sulfur compound is preferably 10% by mass or less, more preferably 5% by mass or less, based on the total amount of the composition, from the point that an effect commensurate with the addition amount cannot be obtained even if blended more than that. More preferably, it is 3 mass% or less, Most preferably, it is 1 mass% or less.

  The lubricating oil composition for machine tools of the present invention may be composed of the lubricating base oil according to the present invention and a compound containing phosphorus and / or sulfur as constituent elements, in order to further improve the characteristics thereof. In addition, you may further contain the additive shown below.

  The lubricating oil composition for machine tools of the present invention may further contain a dispersion type viscosity index improver from the viewpoint of sludge suppression.

  As the dispersion-type viscosity index improver, any compound used as a dispersion-type viscosity index improver for lubricating oils can be used. For example, a copolymer containing a nitrogen-containing monomer having an ethylenically unsaturated bond as a copolymer component. Polymers are preferred. More specifically, one or more monomers selected from the compounds represented by the following general formula (22), (23) or (24) (hereinafter referred to as “monomer (M-1)”); A copolymer with one or more monomers selected from the compounds represented by the following general formula (25) or (26) (hereinafter referred to as “monomer (M-2)”) is preferable.

［式中、Ｒ^４９は水素原子又はメチル基を示し、Ｒ^５０は炭素数１〜１８のアルキル基を示す。］

[Wherein, R ⁴⁹ represents a hydrogen atom or a methyl group, and R ⁵⁰ represents an alkyl group having 1 to 18 carbon atoms. ]

［式中、Ｒ^５１は水素原子又はメチル基を示し、Ｒ^５２は炭素数１〜１２の炭化水素基を示す。］

[Wherein, R ⁵¹ represents a hydrogen atom or a methyl group, and R ⁵² represents a hydrocarbon group having 1 to 12 carbon atoms. ]

［式中、Ｙ^１及びＹ^２は同一でも異なっていてもよく、それぞれ水素原子、炭素数１〜１８のアルコキシ基、又は炭素数１〜１８のモノアルキルアミノ基を示す。］

[Wherein Y ¹ and Y ² may be the same or different and each represents a hydrogen atom, an alkoxy group having 1 to 18 carbon atoms, or a monoalkylamino group having 1 to 18 carbon atoms. ]

［式中、Ｒ^５３は水素原子又はメチル基を示し、Ｒ^５４は炭素数２〜１８のアルキレン基を示し、ｍは０又は１を示し、Ｙ^３は窒素原子を含有する炭素数１〜３０の有機基を示す。］

[Wherein, R ⁵³ represents a hydrogen atom or a methyl group, R ⁵⁴ represents an alkylene group having 2 to 18 carbon atoms, m represents 0 or 1, and Y ³ represents 1 to 30 carbon atoms containing a nitrogen atom. An organic group of ]

［式中、Ｒ^５５は水素原子又はメチル基を示し、Ｙ^５６は窒素原子を含有する炭素数１〜３０の有機基を示す。］

[Wherein, R ⁵⁵ represents a hydrogen atom or a methyl group, and Y ⁵⁶ represents a C 1-30 organic group containing a nitrogen atom. ]

Specific examples of the alkyl group having 1 to 18 carbon atoms represented by R ⁵⁰ in the general formula (22) include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, and an octyl group. Group, nonyl group, decyl group, undecyl group, dodecyl group, tridecyl group, tetradecyl group, pentadecyl group, hexadecyl group, heptadecyl group, octadecyl group, etc. alkyl groups (these alkyl groups may be linear or branched) Is mentioned.

Specific examples of the hydrocarbon group having 1 to 12 carbon atoms represented by R ⁵² in the general formula (23) include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, Alkyl groups such as octyl, nonyl, decyl, undecyl, dodecyl (these alkyl groups may be linear or branched); butenyl, pentenyl, hexenyl, heptenyl, octenyl, nonenyl Groups, decenyl groups, undecenyl groups, dodecenyl groups and the like (these alkenyl groups may be linear or branched); C5-C7 cycloalkyl groups such as cyclopentyl, cyclohexyl, and cycloheptyl Methylcyclopentyl group, dimethylcyclopentyl group, methylethylcyclopentyl group, diethylcyclopentyl group, methyl An alkylcycloalkyl group having 6 to 11 carbon atoms such as a cyclohexyl group, a dimethylcyclohexyl group, a methylethylcyclohexyl group, a diethylcyclohexyl group, a methylcycloheptyl group, a dimethylcycloheptyl group, a methylethylcycloheptyl group, or a diethylcycloheptyl group (alkyl The group may be linear or branched, and the bonding position to the cycloalkyl group is also arbitrary); aryl groups such as phenyl group, naphthyl group; tolyl group, xylyl group, ethylphenyl group, propylphenyl group Each alkylaryl group having 7 to 12 carbon atoms such as butylphenyl group, pentylphenyl group, hexylphenyl group (the alkyl group may be linear or branched, and the bonding position to the aryl group is arbitrary) ); Benzyl group, phenylethyl group, phenylpropyl group C7-12 arylalkyl groups such as phenylbutyl group, phenylpentyl group, phenylhexyl group (the alkyl group may be linear or branched, and the bonding position of the aryl group to the alkyl group is arbitrary) ) And the like.

The alkoxy group having 1 to 18 carbon atoms represented by Y ¹ and Y ² in the general formula (24) is a residue obtained by removing a hydrogen atom from a hydroxyl group of an alkyl alcohol having 1 to 18 carbon atoms (—OR ⁵⁷ ; R ⁵⁷ Is an alkyl group having 1 to 18 carbon atoms. The alkyl group having 1 to 18 carbon atoms represented by R ^57, include the exemplified alkyl group in the description of the alkyl group having 1 to 18 carbon atoms represented by ^{R 50} in the general formula (22).

The monoalkylamino group having 1 to 18 carbon atoms represented by Y ¹ and Y ² in the general formula (24) is a residue (—NHR) obtained by removing a hydrogen atom from the amino group of a monoalkylamine having 1 to 18 carbon atoms. ⁵⁸ ; R ⁵⁸ represents an alkyl group having 1 to 18 carbon atoms. The alkyl group having 1 to 18 carbon atoms represented by R ^58, include the exemplified alkyl group in the description of the alkyl group having 1 to 18 carbon atoms represented by ^{R 50} in the general formula (22).

Specific examples of the alkylene group having 2 to 18 carbon atoms represented by R ⁵⁴ in the general formula (25) include ethylene group, propylene group, butylene group, pentylene group, hexylene group, heptylene group, octylene group, Nonylene group, decylene group, undecylene group, dodecylene group, tridecylene group, tetradecylene group, pentadecylene group, hexadecylene group, heptadecylene group, octadecylene group and other alkylene groups (these alkylene groups may be linear or branched), etc. Can be mentioned.

Y ³ in the general formula (25) and Y ⁴ in the general formula (26) are each a C 1-30 organic group containing a nitrogen atom. The number of nitrogen atoms in the organic group represented by Y ³ and Y ⁴ is not particularly limited, but is preferably one. Further, the carbon number of the organic group represented by ^{Y 3} and ^{Y 4} are as defined above 30, preferably 1 to 20, more preferably 1 to 16.

The organic group represented by Y ³ and Y ⁴ is preferably a group further containing an oxygen atom, and is preferably a group having a ring. In particular, from the viewpoint of sludge suppression, the organic group represented by Y ³ and Y ⁴ preferably has a ring containing an oxygen atom. Further, when the organic group represented by Y ³ and Y ⁴ is a group having a ring, the ring may be either an aliphatic ring or an aromatic ring, but is preferably an aliphatic ring. Further, the ring having an organic group represented by Y ³ and Y ^4, from the viewpoint of sludge inhibiting properties, it is preferably a 6-membered ring.

Specific examples of the organic group represented by Y ³ and Y ⁴ include a dimethylamino group, a diethylamino group, a dipropylamino group, a dibutylamino group, an anilino group, a toluidino group, a xylidino group, an acetylamino group, and a benzoylamino group. Morpholino group, pyrrolyl group, pyrrolino group, pyridyl group, methylpyridyl group, pyrrolidinyl group, piperidinyl group, quinonyl group, pyrrolidonyl group, pyrrolidono group, imidazolino group, pyrazino group, etc., among which morpholino group is particularly preferable .

  Preferred examples of the compounds represented by the above general formulas (22) to (24) include alkyl acrylates having 1 to 18 carbon atoms, alkyl methacrylates having 1 to 18 carbon atoms, olefins having 2 to 20 carbon atoms, styrene, Examples thereof include methylstyrene, maleic anhydride ester, maleic anhydride amide, and a mixture thereof.

  Preferred examples of the compound represented by the general formula (25) or (26) include dimethylaminomethyl methacrylate, diethylaminomethyl methacrylate, dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate, 2-methyl-5-vinylpyridine, Examples include morpholinomethyl methacrylate, morpholinoethyl methacrylate, N-vinylpyrrolidone, and mixtures thereof.

  Among the compounds represented by the general formulas (22) to (24), from the viewpoint of viscosity-temperature characteristics, the monomer (M-1) is preferably a compound represented by the general formula (22). On the other hand, the monomer (M-2) is preferably a compound represented by the general formula (25) among the compounds represented by the general formula (25) or (26) from the viewpoint of sludge suppression.

  In copolymerizing the monomer (M-1) and the monomer (M-2), the polymerization ratio (molar ratio) of the monomer (M-1) and the monomer (M-2) is arbitrary, but 80:20 It is preferable to be within the range of ~ 95: 5. The copolymerization reaction method is also arbitrary. Usually, the monomer (M-1) and the monomer (M-2) are subjected to radical solution polymerization in the presence of a polymerization initiator such as benzoyl peroxide. This copolymer can be obtained easily and reliably. Although the number average molecular weight of the copolymer obtained is also arbitrary, Preferably it is 1,000-1,500,000, More preferably, it is 10,000-200,000.

  The content of the dispersion type viscosity index improver in the lubricating oil composition for machine tools of the present invention is preferably 10% by mass or less, more preferably 5% by mass or less, and further preferably 2% by mass, based on the total amount of the composition. is there. Even if the content of the dispersion-type viscosity index improver exceeds 10% by mass, no further improvement in the sludge inhibiting property commensurate with the content is observed, and a decrease in viscosity due to shearing is caused, which is not preferable. The content of the dispersion type viscosity index improver is preferably 0.01% by mass or more, more preferably 0.05% by mass, and still more preferably 0.1% by mass or more based on the total amount of the composition. When the content of the dispersion type viscosity index improver is less than 0.01% by mass, the effect of improving the sludge suppression by the addition tends to be insufficient.

Moreover, it is preferable that the lubricating oil composition for machine tools of this invention contains at least 1 sort (s) chosen from the compound represented by the following general formula (27)-(29) from the point which can further improve a friction characteristic.
^{_{R 59 -CO-NR 60 - (}} CH 2) p -COOX 5 (27)
[Wherein, R ⁵⁹ represents an alkyl group having 6 to 30 carbon atoms or an alkenyl group having 6 to 30 carbon atoms, R ⁶⁰ represents an alkyl group having 1 to 4 carbon atoms, X ⁵ represents a hydrogen atom, and 1 carbon atom. Represents an -30 alkyl group or an alkenyl group having 1 to 30 carbon atoms, and p represents an integer of 1 to 4. ]
_{^{[R 61 -CO-NR 62 -}} (CH 2) q -COO] r Y 5 (28)
[Wherein, R ⁶¹ represents an alkyl group having 6 to 30 carbon atoms or an alkenyl group having 6 to 30 carbon atoms, R ⁶² represents an alkyl group having 1 to 4 carbon atoms, and Y ⁵ represents an alkali metal atom or alkaline earth. N represents an integer of 1 to 4, and r represents 1 when Y ⁵ is an alkali metal atom, and 2 when Y ⁵ is an alkaline earth metal. ]
_{^{[R 63 -CO-NR 64 -}} (CH 2) s -COO] t -Z- (OH) u (29)
[Wherein R ⁶³ represents an alkyl group having 6 to 30 carbon atoms or an alkenyl group having 6 to 30 carbon atoms, R ⁶⁴ represents an alkyl group having 1 to 4 carbon atoms, and Z represents a polyhydric alcohol having two or more valences. The residue remove | excluding the hydroxyl group from is shown, s shows the integer of 1-4, t shows the integer of 1 or more, and u shows the integer of 0 or more. ]

In General Formulas (27) to (29), R ⁵⁹ , R ⁶¹ , and R ⁶³ each represent an alkyl group having 6 to 30 carbon atoms or an alkenyl group having 6 to 30 carbon atoms. The number of carbon atoms of the alkyl group or alkenyl group represented by R ⁵⁹ , R ⁶¹ , R ⁶³ is 6 or more, preferably 7 or more, more preferably 8 or more, from the viewpoint of solubility in a lubricating base oil. In view of storage stability, the alkyl group or alkenyl group represented by R ⁵⁹ , R ⁶¹ , and R ⁶³ has 30 or less carbon atoms, preferably 24 or less, and more preferably 20 or less. Specific examples of such alkyl groups and alkenyl groups include hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, Alkyl groups such as heptadecyl group, octadecyl group, nonadecyl group, icosyl group (these alkyl groups may be linear or branched); hexenyl group, heptenyl group, octenyl group, nonenyl group, decenyl group, undecenyl group, dodecenyl group Group, tridecenyl group, tetradecenyl group, pentadecenyl group, hexadecenyl group, heptadecenyl group, octadecenyl group, nonadecenyl group, icocenyl group and the like alkenyl groups (these alkenyl groups may be linear or branched, and the position of the double bond) Are also optional)

In general formulas (27) to (29), R ⁶⁰ , R ⁶² , and R ⁶⁴ each represent an alkyl group having 1 to 4 carbon atoms. The carbon number of the alkyl group represented by R ⁶⁰ , R ⁶² , or R ⁶⁴ is 4 or less, preferably 3 or less, more preferably 2 or less, from the viewpoint of storage stability.

  Moreover, in general formula (27)-(29), p, q, and s show the integer of 1-4, respectively. p, q, and s are required to be an integer of 4 or less from the viewpoint of storage stability and the like, preferably 3 or less, and more preferably 2 or less.

Further, in the general formula (27), ^{X 5} represents a hydrogen atom, an alkyl group or alkenyl group having 1 to 30 carbon atoms having 1 to 30 carbon atoms. The number of carbon atoms of the alkyl group or alkenyl group represented by X ⁵ is 30 or less, preferably 20 or less, more preferably 10 or less, from the viewpoint of storage stability. Specific examples of such an alkyl group or alkenyl group include alkyl groups such as a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, and a decyl group. (These alkyl groups may be linear or branched); alkenyl groups such as ethenyl, propenyl, butenyl, pentenyl, hexenyl, heptenyl, octenyl, nonenyl, decenyl (these alkenyl groups) May be linear or branched, and the position of the double bond is arbitrary). X ⁵ is preferably an alkyl group from the viewpoint of excellent sludge suppression. Further, from the viewpoint of improving the friction characteristics and improving the durability of the friction characteristics effect, X ⁵ is a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, or an alkenyl group having 1 to 20 carbon atoms. It is preferably a hydrogen atom or an alkyl group having 1 to 20 carbon atoms, more preferably a hydrogen atom or an alkyl group having 1 to 10 carbon atoms.

In the general formula (28), Y ⁵ represents an alkali metal atom or alkaline earth metal atom, specifically, for example, sodium, potassium, magnesium, calcium, and the like. Among these, alkaline earth metals are preferable from the viewpoint of improving the sustainability of the friction characteristic effect. In the general formula (28), r represents 1 when Y ⁵ is an alkali metal, and represents 2 when Y ⁵ is an alkaline earth metal.

  In general formula (29), Z represents the residue remove | excluding the hydroxyl group from the polyhydric alcohol more than bivalence. Specific examples of such polyhydric alcohols include ethylene glycol, propylene glycol, 1,4-butanediol, 1,2-butanediol, neopentyl glycol, 1,6-hexanediol, 1,2- Octanediol, 1,8-octanediol, isoprene glycol, 3-methyl-1,5-pentanediol, sorbite, catechol, resorcin, hydroquinone, bisphenol A, bisphenol F, hydrogenated bisphenol A, hydrogenated bisphenol F, dimer diol Divalent alcohols such as glycerin, 2- (hydroxymethyl) -1,3-propanediol, 1,2,3-butanetriol, 1,2,3-pentanetriol, 2-methyl-1,2,3 -Propanetriol, 2-methyl-2,3,4- Tantriol, 2-ethyl-1,2,3-butanetriol, 2,3,4-pentanetriol, 2,3,4-hexanetriol, 4-propyl-3,4,5-heptanetriol, 2,4 -Trihydric alcohols such as dimethyl-2,3,4-pentanetriol, 1,2,4-butanetriol, 1,2,4-pentanetriol, trimethylolethane, trimethylolpropane; pentaerythritol, erythritol, 1, 2,3,4-pentanetetrol, 2,3,4,5-hexanetetrol, 1,2,4,5-pentanetetrol, 1,3,4,5-hexanetetrol, diglycerin, sorbitan Tetrahydric alcohols such as adonitol, arabitol, xylitol, triglycerin, etc .; dipentaerythritol Le, sorbitol, mannitol, iditol, inositol, dulcitol, talose, hexavalent alcohols such as allose, polyglycerin or their dehydrated condensates and the like.

  In general formula (29), t is an integer of 1 or more, u is an integer of 0 or more, and t + u is the same as the valence of Z. That is, all of the hydroxyl groups of the polyhydric alcohol that gives the residue Z may be substituted, or only a part thereof may be substituted.

Among the compounds selected from the general formulas (27) to (29), at least one selected from the compounds represented by the general formulas (27) and (28) from the viewpoint of improving the durability of the friction characteristic effect. Species are preferred. Preferable examples of the compound represented by the general formula (27) include N-oleoyl sarcosine in which R ⁵⁹ is an alkenyl group having 17 carbon atoms, R ⁶⁰ is a methyl group, X ⁵ is a hydrogen atom, and p is 1. It is done.

  In addition, the compound represented by General formula (27)-(29) may be used individually by 1 type, and may be used in combination of 2 or more type.

  The content of the compounds represented by the general formulas (27) to (29) is preferably 5% by mass or less, more preferably 2% by mass or less, and still more preferably 1% by mass or less, based on the total amount of the composition. Even if the content of the compounds represented by the general formulas (27) to (29) exceeds 5% by mass, no further improvement in the frictional properties commensurate with the content is observed, and the storage stability tends to decrease. It is in. The content of the compounds represented by the general formulas (27) to (29) is preferably 0.001% by mass or more, more preferably 0.003% by mass or more, and still more preferably 0, based on the total amount of the composition. 0.005% by mass or more. When the content of the compounds represented by the general formulas (27) to (29) is less than 0.001% by mass, the effect of improving the friction characteristics due to the addition tends to be insufficient.

Moreover, the lubricating oil composition for machine tools of this invention can contain the compound represented by following General formula (30) from the point which a friction characteristic improves more.
R ⁶⁵ —CH ₂ COOH (30)
[Wherein R ⁶⁵ represents an alkyl group having 7 to 29 carbon atoms, an alkenyl group having 7 to 29 carbon atoms, or the following general formula (31):
R ⁶⁶ -C ₆ H ₄ O- (31)
(In the formula, R ⁶⁶ represents an alkyl group having 1 to 20 carbon atoms or a hydrogen atom.)
The group represented by these is shown. ]

When R ⁶⁵ in the general formula (30) is an alkyl group, the carbon number of the alkyl group is 7 or more, preferably 9 or more, from the viewpoint of solubility in a lubricating base oil. From the viewpoint of storage stability and the like, the alkyl group has 29 or less carbon atoms, preferably 22 or less, and more preferably 19 or less. Specific examples of such alkyl groups include heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, A nonadecyl group and the like (these alkyl groups may be linear or branched).

When R ⁶⁵ in the general formula (30) is an alkenyl group, the carbon number of the alkenyl group is 7 or more, preferably 9 or more, from the viewpoint of solubility in a lubricating base oil. In view of storage stability, the alkenyl group has 29 or less carbon atoms, preferably 22 or less, and more preferably 19 or less. Specific examples of such alkenyl groups include heptenyl, octenyl, nonenyl, decenyl, undecenyl, dodecenyl, tridecenyl, tetradecenyl, pentadecenyl, hexadecenyl, heptadecenyl, octadecenyl, A nonadecenyl group and the like (these alkenyl groups may be linear or branched).

When ^{R 65} in formula (31) in is a group represented by the general formula (31), ^{R 66} in the general formula (31) is an alkyl group or a hydrogen atom having 1 to 20 carbon atoms. The number of carbon atoms of the alkyl group represented by R ⁶⁶ is 20 or less, preferably 19 or less, more preferably 15 or less, from the viewpoint of storage stability. Moreover, the carbon number of the alkyl group is 3 or more, preferably 5 or more, from the viewpoint of solubility in a lubricating base oil. In addition, when R ⁶⁶ is an alkyl group, the substitution position on the benzene ring of the alkyl group is arbitrary, but from the point of being superior in the effect of improving the frictional characteristics, with respect to —CH ₂ COOH in the general formula (30) The para position or the meta position is preferable, and the para position is more preferable.

In the general formula (30), R ⁶⁵ may be any of an alkyl group having 7 to 29 carbon atoms, an alkenyl group having 7 to 29 carbon atoms, or a group represented by the general formula (31). From the standpoint of superiority, it is preferably a group represented by the general formula (31).

  The content of the compound represented by the general formula (30) is arbitrary, but if mixed in a large amount, there is a risk that the sludge inhibiting property may be lowered. Therefore, the total amount is preferably 5% by mass or less, more preferably Is 1% by mass or less, more preferably 0.5% by mass or less. On the other hand, the content of the compound represented by the general formula (30) is preferably 0.001% by mass or more based on the total amount of the composition, more preferably 0.001% by mass or more from the viewpoint of sufficiently exerting the effect of improving the friction characteristics. It is 0.003 mass% or more, More preferably, it is 0.005 mass% or more.

Moreover, the lubricating oil composition for machine tools of this invention can contain an epoxy compound from the point of sludge suppression property. Examples of the epoxy compound include those shown below.
(1) Phenyl glycidyl ether type epoxy compound,
(2) Alkyl glycidyl ether type epoxy compound (3) Glycidyl ester type epoxy compound (4) Allyl oxirane compound (5) Alkyl oxirane compound (6) Alicyclic epoxy compound (7) Epoxidized fatty acid monoester (8) Epoxidation Vegetable oil.

  (1) Specific examples of the phenyl glycidyl ether type epoxy compound include phenyl glycidyl ether and alkylphenyl glycidyl ether. As used herein, the alkylphenyl glycidyl ether includes those having 1 to 3 alkyl groups having 1 to 13 carbon atoms, and those having one alkyl group having 4 to 10 carbon atoms, such as n-butylphenyl glycidyl. Ether, i-butylphenyl glycidyl ether, sec-butylphenyl glycidyl ether, tert-butylphenyl glycidyl ether, pentylphenyl glycidyl ether, hexylphenyl glycidyl ether, heptylphenyl glycidyl ether, octylphenyl glycidyl ether, nonylphenyl glycidyl ether, decylphenyl A glycidyl ether etc. can be illustrated as a preferable thing.

  (2) As the alkyl glycidyl ether type epoxy compound, specifically, decyl glycidyl ether, undecyl glycidyl ether, dodecyl glycidyl ether, tridecyl glycidyl ether, tetradecyl glycidyl ether, 2-ethylhexyl glycidyl ether, neopentyl glycol di Examples thereof include glycidyl ether, trimethylolpropane triglycidyl ether, pentaerythritol tetraglycidyl ether, 1,6-hexanediol diglycidyl ether, sorbitol polyglycidyl ether, polyalkylene glycol monoglycidyl ether, polyalkylene glycol diglycidyl ether and the like.

  (3) Specific examples of the glycidyl ester type epoxy compound include compounds represented by the following general formula (32).

［式中、Ｒ^６７は炭素数１〜１８の炭化水素基を表す。］

[Wherein, R ⁶⁷ represents a hydrocarbon group having 1 to 18 carbon atoms. ]

In the above formula (32), R ⁶⁷ represents a hydrocarbon group having 1 to 18 carbon atoms. Examples of such a hydrocarbon group include an alkyl group having 1 to 18 carbon atoms, an alkenyl group having 2 to 18 carbon atoms, C5-C7 cycloalkyl group, C6-C18 alkylcycloalkyl group, C6-C10 aryl group, C7-C18 alkylaryl group, C7-C18 arylalkyl group, etc. Is mentioned. Among these, an alkylphenyl group having an alkyl group having 5 to 15 carbon atoms, an alkenyl group having 2 to 15 carbon atoms, a phenyl group, and an alkyl group having 1 to 4 carbon atoms is preferable.

  Among the glycidyl ester type epoxy compounds, preferred examples include glycidyl-2,2-dimethyloctanoate, glycidyl benzoate, glycidyl-tert-butyl benzoate, glycidyl acrylate, glycidyl methacrylate, and the like.

  (4) Specific examples of the allyloxirane compound include 1,2-epoxystyrene, alkyl-1,2-epoxystyrene, and the like.

  (5) Specific examples of the alkyloxirane compound include 1,2-epoxybutane, 1,2-epoxypentane, 1,2-epoxyhexane, 1,2-epoxyheptane, 1,2-epoxyoctane, 1 , 2-epoxynonane, 1,2-epoxydecane, 1,2-epoxyundecane, 1,2-epoxydodecane, 1,2-epoxytridecane, 1,2-epoxytetradecane, 1,2-epoxypentadecane, 1, 2,2-epoxyhexadecane, 1,2-epoxyheptadecane, 1,1,2-epoxyoctadecane, 2-epoxynonadecane, 1,2-epoxyicosane and the like.

  (6) As an alicyclic epoxy compound, the compound in which the carbon atom which comprises an epoxy group directly comprises the alicyclic ring like the compound represented by the following general formula (33) is mentioned.

  Specific examples of the alicyclic epoxy compound include 1,2-epoxycyclohexane, 1,2-epoxycyclopentane, 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate, and bis (3,4 -Epoxycyclohexylmethyl) adipate, exo-2,3-epoxynorbornane, bis (3,4-epoxy-6-methylcyclohexylmethyl) adipate, 2- (7-oxabicyclo [4.1.0] hept-3- Yl) -spiro (1,3-dioxane-5,3 ′-[7] oxabicyclo [4.1.0] heptane, 4- (1′-methylepoxyethyl) -1,2-epoxy-2-methyl Examples include cyclohexane and 4-epoxyethyl-1,2-epoxycyclohexane.

  (7) Specific examples of the epoxidized fatty acid monoester include esters of an epoxidized fatty acid having 12 to 20 carbon atoms with an alcohol or phenol having 1 to 8 carbon atoms or an alkylphenol. In particular, butyl, hexyl, benzyl, cyclohexyl, methoxyethyl, octyl, phenyl and butylphenyl esters of epoxy stearate are preferably used.

  (8) Specific examples of epoxidized vegetable oils include epoxy compounds of vegetable oils such as soybean oil, linseed oil, and cottonseed oil.

  When the lubricating oil composition for machine tools of the present invention contains an epoxy compound, the content is not particularly limited, but is preferably 0.1 to 5.0% by mass, more preferably 0.8%, based on the total amount of the composition. 2 to 2.0% by mass.

  Moreover, the lubricating oil composition for machine tools of this invention can contain a phenolic antioxidant, an amine antioxidant, or both from the point which can further improve oxidation stability.

  As the phenolic antioxidant, any phenolic compound used as an antioxidant for lubricating oil can be used, and is not particularly limited. For example, the following general formula (34) or general formula One or more alkylphenol compounds selected from the compounds represented by (35) are preferred.

［式中、Ｒ^６８は炭素数１〜４のアルキル基を示し、Ｒ^６９は水素原子又は炭素数１〜４のアルキル基を示し、Ｒ^７０は水素原子、炭素数１〜４のアルキル基、下記一般式（３４−ｉ）で表される基又は下記一般式（３４−ｉｉ）で表される基を示す。

（式中、Ｒ^７１は炭素数１〜６のアルキレン基を示し、Ｒ^７２は炭素数１〜２４のアルキル基又はアルケニル基を示す。）

（式中、Ｒ^７３は炭素数１〜６のアルキレン基を示し、Ｒ^７４は炭素数１〜４のアルキル基を示し、Ｒ^７５は水素原子又は炭素数１〜４のアルキル基を示す。）］

[Wherein, R ⁶⁸ represents an alkyl group having 1 to 4 carbon atoms, R ⁶⁹ represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, R ⁷⁰ represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, The group represented by the following general formula (34-i) or the group represented by the following general formula (34-ii) is shown.

(In the formula, R ⁷¹ represents an alkylene group having 1 to 6 carbon atoms, and R ⁷² represents an alkyl group or alkenyl group having 1 to 24 carbon atoms.)

(In the formula, R ⁷³ represents an alkylene group having 1 to 6 carbon atoms, R ⁷⁴ represents an alkyl group having 1 to 4 carbon atoms, and R ⁷⁵ represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms.) ]

［式中、Ｒ^７６及びＲ^８０は同一でも異なっていてもよく、それぞれ炭素数１〜４のアルキル基を示し、Ｒ^７７及びＲ^８１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１〜４のアルキル基を示し、Ｒ^７８及びＲ^７９は同一でも異なっていてもよく、それぞれ炭素数１〜６のアルキレン基を示し、Ｗは炭素数１〜１８のアルキレン基又は下記一般式（３５−ｉ）で表される基を示す。
−Ｒ^８２−Ｓ−Ｒ^８３− （３５−ｉ）
（式中、Ｒ^８２及びＲ^８３は同一でも異なっていてもよく、それぞれ炭素数１〜６のアルキレン基を示す。）］

[Wherein, R ⁷⁶ and R ⁸⁰ may be the same or different and each represents an alkyl group having 1 to 4 carbon atoms; R ⁷⁷ and R ⁸¹ may be the same or different and each represents a hydrogen atom or a carbon number; 1 to 4 alkyl groups, R ⁷⁸ and R ⁷⁹ may be the same or different and each represents an alkylene group having 1 to 6 carbon atoms, and W represents an alkylene group having 1 to 18 carbon atoms or the following general formula ( The group represented by 35-i) is shown.
^{-R 82 -S-R 83 - (} 35-i)
(Wherein R ⁸² and R ⁸³ may be the same or different and each represents an alkylene group having 1 to 6 carbon atoms)]

In the general formula (34), R ⁶⁸ specifically includes methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group and the like. Although mentioned, a tert- butyl group is preferable from the point which is excellent in oxidation stability. Examples of R ⁶⁹ include a hydrogen atom and an alkyl group having 1 to 4 carbon atoms as described above, and a methyl group or a tert-butyl group is preferable from the viewpoint of excellent thermal and oxidation stability.

In the general formula (34), when R ⁷⁰ is an alkyl group having 1 to 4 carbon atoms, specifically, R ⁶¹ is methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, An isobutyl group, a sec-butyl group, a tert-butyl group and the like can be mentioned, and a methyl group or an ethyl group is preferable from the viewpoint of excellent oxidation stability.

Among the alkylphenol compounds represented by the general formula (34), particularly preferred as a compound when R ⁷⁰ is an alkyl group having 1 to 4 carbon atoms is 2,6-di-tert-butyl-p-cresol. 2,6-di-tert-butyl-4-ethylphenol and mixtures thereof.

In case ^{R 70} in the general formula (34) in is a group represented by the general formula (34-i), an alkylene group having 1 to 6 carbon atoms represented by ^{R 71} in formula (34-i) is It may be linear or branched. Specifically, for example, methylene group, methylmethylene group, ethylene group (dimethylene group), ethylmethylene group, propylene group (methylethylene group), trimethylene group, linear chain Or a branched butylene group, a linear or branched pentylene group, a linear or branched hexylene group, etc. are mentioned.

R ⁷¹ is an alkylene group having 1 to 2 carbon atoms, specifically, for example, a methylene group, a methylmethylene group, an ethylene group (dimethylene group), in that the compound represented by the general formula (34) can be produced by a reaction process with few. Etc. are more preferable.

On the other hand, the alkyl group or alkenyl group having 1 to 24 carbon atoms represented by R ⁷² in the general formula (34-i) may be linear or branched, and specifically includes, for example, methyl group, ethyl group Propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, nonadecyl Group, icosyl group, henicosyl group, docosyl group, tricosyl group, tetracosyl group and the like (these alkyl groups may be linear or branched); vinyl group, propenyl group, isopropenyl group, butenyl group, Pentenyl, hexenyl, heptenyl, octenyl, nonenyl, decenyl, undecenyl, dopenyl Decenyl group, tridecenyl group, tetradecenyl group, pentadecenyl group, hexadecenyl group, heptadecenyl group, octadecenyl group, octadecadienyl group, nonadecenyl group, icocenyl group, heicocosenyl group, dococenyl group, tricocenyl group, tetracocenyl group, etc. The alkenyl group may be linear or branched, and the position of the double bond is arbitrary).

R ⁷² is preferably an alkyl group having 4 to 18 carbon atoms from the viewpoint of excellent solubility in a lubricating base oil. Specifically, for example, butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl Group, decyl group, undecyl group, dodecyl group, tridecyl group, tetradecyl group, pentadecyl group, hexadecyl group, heptadecyl group, octadecyl group and other alkyl groups (these alkyl groups may be linear or branched) are preferred. Further, a linear or branched alkyl group having 6 to 12 carbon atoms is more preferable, and a branched alkyl group having 6 to 12 carbon atoms is particularly preferable.

Among the phenol compounds represented by the general formula (34), as a compound in the case where R ⁷⁰ is a group represented by the general formula (34-i), R ⁷¹ in the general formula (34-i) is carbon. More preferably, it is an alkylene group having 1 or 2 and R ⁷² is a linear or branched alkyl group having 6 to 12 carbon atoms, and R ⁷¹ in the general formula (34-i) is 1 to 1 carbon atoms. Particularly preferred is an alkylene group having 2 and R ⁷² is a branched alkyl group having 6 to 12 carbon atoms.

  More specific examples of the more preferable compound include (3-methyl-5-tert-butyl-4-hydroxyphenyl) acetate n-hexyl, (3-methyl-5-tert-butyl-4-hydroxyphenyl) isohexyl acetate, N-heptyl (3-methyl-5-tert-butyl-4-hydroxyphenyl) acetate, isoheptyl (3-methyl-5-tert-butyl-4-hydroxyphenyl) acetate, (3-methyl-5-tert-butyl) -4-hydroxyphenyl) acetic acid n-octyl, (3-methyl-5-tert-butyl-4-hydroxyphenyl) isooctyl acetate, (3-methyl-5-tert-butyl-4-hydroxyphenyl) acetic acid 2-ethylhexyl , (3-Methyl-5-tert-butyl-4-hydroxyphenyl) acetic acid n-no , Isononyl (3-methyl-5-tert-butyl-4-hydroxyphenyl) acetate, n-decyl (3-methyl-5-tert-butyl-4-hydroxyphenyl) acetate, (3-methyl-5-tert -Butyl-4-hydroxyphenyl) isodecyl acetate, (3-methyl-5-tert-butyl-4-hydroxyphenyl) n-undecyl acetate, (3-methyl-5-tert-butyl-4-hydroxyphenyl) isoundecyl acetate N-dodecyl (3-methyl-5-tert-butyl-4-hydroxyphenyl) acetate, isododecyl (3-methyl-5-tert-butyl-4-hydroxyphenyl) acetate, (3-methyl-5-tert- N-hexyl butyl-4-hydroxyphenyl) propionate, (3-methyl-5-tert-butyl) 4-Hydroxyphenyl) isohexyl propionate, n-heptyl (3-methyl-5-tert-butyl-4-hydroxyphenyl) propionate, (3-methyl-5-tert-butyl-4-hydroxyphenyl) propion Isoheptyl acid, n-octyl (3-methyl-5-tert-butyl-4-hydroxyphenyl) propionate, isooctyl (3-methyl-5-tert-butyl-4-hydroxyphenyl) propionate, (3-methyl- 5-tert-butyl-4-hydroxyphenyl) propionic acid 2-ethylhexyl, (3-methyl-5-tert-butyl-4-hydroxyphenyl) propionic acid n-nonyl, (3-methyl-5-tert-butyl- 4-hydroxyphenyl) isononyl propionate, (3-methyl N-decyl til-5-tert-butyl-4-hydroxyphenyl) propionate, isodecyl (3-methyl-5-tert-butyl-4-hydroxyphenyl) propionate, (3-methyl-5-tert-butyl- 4-hydroxyphenyl) n-undecyl propionate, (3-methyl-5-tert-butyl-4-hydroxyphenyl) isoundecyl propionate, (3-methyl-5-tert-butyl-4-hydroxyphenyl) propionate n -Dodecyl, isododecyl (3-methyl-5-tert-butyl-4-hydroxyphenyl) propionate, (3,5-di-tert-butyl-4-hydroxyphenyl) acetate n-hexyl, (3,5-di-) -Tert-butyl-4-hydroxyphenyl) isohexyl acetate, (3,5- -Tert-butyl-4-hydroxyphenyl) acetic acid n-heptyl, (3,5-di-tert-butyl-4-hydroxyphenyl) isoheptyl acetate, (3,5-di-tert-butyl-4-hydroxyphenyl) N-octyl acetate, (3,5-di-tert-butyl-4-hydroxyphenyl) isooctyl acetate, (3,5-di-tert-butyl-4-hydroxyphenyl) acetic acid 2-ethylhexyl, (3,5- N-nonyl di-tert-butyl-4-hydroxyphenyl) acetate, isononyl (3,5-di-tert-butyl-4-hydroxyphenyl) acetate, (3,5-di-tert-butyl-4-hydroxyphenyl) ) N-decyl acetate, (3,5-di-tert-butyl-4-hydroxyphenyl) isodecyl acetate, (3,5-di-) tert-butyl-4-hydroxyphenyl) acetic acid n-undecyl, (3,5-di-tert-butyl-4-hydroxyphenyl) isoundecyl acetate, (3,5-di-tert-butyl-4-hydroxyphenyl) acetic acid n-dodecyl, (3,5-di-tert-butyl-4-hydroxyphenyl) isododecyl acetate, (3,5-di-tert-butyl-4-hydroxyphenyl) propionate n-hexyl, (3,5- Di-tert-butyl-4-hydroxyphenyl) isohexyl propionate, n-heptyl (3,5-di-tert-butyl-4-hydroxyphenyl) propionate, (3,5-di-tert-butyl-4- Hydroxyphenyl) isoheptyl propionate, (3,5-di-tert-butyl-4-hydroxypheny N) -octyl propionate, (3,5-di-tert-butyl-4-hydroxyphenyl) isooctyl propionate, 2-ethylhexyl (3,5-di-tert-butyl-4-hydroxyphenyl) propionate, N-nonyl (3,5-di-tert-butyl-4-hydroxyphenyl) propionate, isononyl (3,5-di-tert-butyl-4-hydroxyphenyl) propionate, (3,5-di-tert -Butyl-4-hydroxyphenyl) n-decyl propionate, (3,5-di-tert-butyl-4-hydroxyphenyl) isodecyl propionate, (3,5-di-tert-butyl-4-hydroxyphenyl) N-undecyl propionate, (3,5-di-tert-butyl-4-hydroxyphenyl) propiate Isoundecylate, n-dodecyl (3,5-di-tert-butyl-4-hydroxyphenyl) propionate, isododecyl (3,5-di-tert-butyl-4-hydroxyphenyl) propionate, and mixtures thereof Etc.

In the case where R ⁷⁰ in the general formula (34) is a group represented by the general formula (34-ii), R ⁷³ in the general formula (34-ii) represents an alkylene group having 1 to 6 carbon atoms. . As the alkylene group may be a branched be linear, and specific examples include various alkylene groups exemplified for R ⁷² above. R ⁷³ is an alkylene group having 1 to 3 carbon atoms, specifically, for example, a methylene group, a methylmethylene group, ethylene, because the compound of the general formula (34) can be produced by a reaction process with few compounds and its raw materials are easily available. A group (dimethylene group), ethylmethylene group, propylene group (methylethylene group), trimethylene group and the like are more preferable. In addition, as R ⁷⁴ in the general formula (34-ii), specifically, methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert- Although a butyl group etc. are mentioned, a tert-butyl group is preferable from the point which is excellent in oxidation stability. Examples of R ⁷⁵ include a hydrogen atom or an alkyl group having 1 to 4 carbon atoms as described above, and a methyl group or a tert-butyl group is preferable from the viewpoint of excellent oxidation stability.

Of the alkylphenol compounds represented by the general formula (34), specific examples of preferred compounds in the case where R ⁷⁰ is a group represented by the general formula (34-ii) include bis (3, 5-di-tert-butyl-4-hydroxyphenyl) methane, 1,1-bis (3,5-di-tert-butyl-4-hydroxyphenyl) ethane, 1,2-bis (3,5-di-) tert-butyl-4-hydroxyphenyl) ethane, 1,1-bis (3,5-di-tert-butyl-4-hydroxyphenyl) propane, 1,2-bis (3,5-di-tert-butyl- 4-hydroxyphenyl) propane, 1,3-bis (3,5-di-tert-butyl-4-hydroxyphenyl) propane, 2,2-bis (3,5-di-tert-butyl-4-hydroxy) Siphenyl) propane, and mixtures thereof.

On the other hand, in the general formula (35), R ⁷⁶ and R ⁸⁰ may be the same or different and each represents an alkyl group having 1 to 4 carbon atoms. Specific examples of the alkyl group include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, and a tert-butyl group. From the viewpoint of excellent stability, both are preferably tert-butyl groups.

R ⁷⁷ and R ⁸¹ may be the same or different and each represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. Examples of the alkyl group represented by R ⁷⁷ and R ⁸¹ include the alkyl groups exemplified in the description of R ⁷⁶ and R ^{80. From} the viewpoint of excellent thermal and oxidative stability, each is independently a methyl group or A tert-butyl group is preferred.
In the general formula (35), the alkylene group having 1 to 6 carbon atoms represented by R ⁷⁸ and R ⁷⁹ may be linear or branched, and specifically, alkylene groups exemplified in the description of R ⁷¹ can be mentioned. R ⁷⁸ and R ⁷⁹ are each independently an alkylene group having 1 to 2 carbon atoms in that the compound represented by the general formula (35) can be produced with few reaction steps and the raw material is easily available. Specifically, a methylene group, a methylmethylene group, an ethylene group (dimethylene group), or the like is preferable.

  Further, in the general formula (35), the alkylene group having 1 to 18 carbon atoms represented by W specifically includes, for example, a methylene group, a methylmethylene group, an ethylene group (dimethylene group), an ethylmethylene group, and a propylene group. (Methylethylene group), trimethylene group, butylene group, pentylene group, hexylene group, heptylene group, octylene group, nonylene group, decylene group, undecylene group, dodecylene group, tridecylene group, tetradecylene group, pentadecylene group, hexadecylene group, heptadecylene group , Octadecylene groups and the like (these alkylene groups may be linear or branched). From the viewpoint of easy availability of raw materials, an alkylene group having 1 to 6 carbon atoms, specifically, for example, a methylene group , Methylmethylene group, ethylene group (dimethylene group), ethylmethylene group, Pyrene group (methylethylene group), trimethylene group, butylene group, pentylene group, hexylene group and the like (these alkylene groups may be linear or branched) are more preferable, ethylene group (dimethylene group), trimethylene group, A linear alkylene group having 2 to 6 carbon atoms such as a linear butylene group (tetramethylene group, linear pentylene group (pentamethylene group), linear hexylene group (hexamethylene group), etc. is particularly preferred. Among the alkylphenol compounds represented, a compound represented by the following formula (36) is particularly preferable as a compound when W is an alkylene group having 1 to 18 carbon atoms.

In the case where W in the general formula (35) is a group represented by the general formula (35-i), the carbon number of 1 to 6 represented by R ⁸² and R ⁸³ in the general formula (35-i) The alkylene group may be linear or branched, and specific examples thereof include the alkylene groups exemplified in the description of R ⁷¹ . Since the raw materials for producing the compound represented by the general formula (35) are easily available, R ⁸² and R ⁸³ are each independently an alkylene group having 1 to 3 carbon atoms, specifically, for example, methylene. More preferably a group, a methylmethylene group, an ethylene group (dimethylene group), an ethylmethylene group, a propylene group (methylethylene group), a trimethylene group, or the like. Of the alkylphenols represented by the general formula (35), a compound represented by the following formula (37) is particularly preferable as a compound when W is a group represented by the general formula (35-i). is there.

  In the present invention, one kind selected from the alkylphenol compound represented by the general formula (31) and the alkylphenol compound represented by the general formula (32) may be used alone, or two or more compounds are combined. May be used.

  The content of the phenolic antioxidant in the lubricating oil composition for machine tools of the present invention is preferably 3% by mass or less, more preferably 2% by mass or less, and still more preferably 1% by mass, based on the total amount of the composition. . Even if the content of the phenolic antioxidant exceeds 3% by mass, there is no further improvement in thermal / oxidative stability and sludge suppression that is commensurate with the content, and solubility in lubricating base oils. Tends to be insufficient. The content of the phenolic antioxidant is preferably 0.01% by mass or more, more preferably 0.1% by mass or more, and further preferably 0.2% by mass or more, based on the total amount of the composition. When the content of the phenolic antioxidant is less than 0.01% by mass, the effect of improving the heat / oxidation stability and sludge suppression by the addition tends to be insufficient.

  As the amine-based antioxidant, any amine-based compound used as an antioxidant for lubricating oil can be used, and is not particularly limited. For example, in the following general formula (38) One or more aromatic amines selected from phenyl-α-naphthylamine represented by the formula and p, p′-dialkyldiphenylamine represented by the general formula (39) are preferred.

［式中、Ｒ^８４は水素原子又は炭素数１〜１６のアルキル基を示す。］

[Wherein, R ⁸⁴ represents a hydrogen atom or an alkyl group having 1 to 16 carbon atoms. ]

［式中、Ｒ^８５及びＲ^８６は同一でも異なっていてもよく、それぞれ炭素数１〜１６のアルキル基を示す。］

[Wherein, R ⁸⁵ and R ⁸⁶ may be the same or different and each represents an alkyl group having 1 to 16 carbon atoms. ]

In the general formula (38) representing phenyl-α-naphthylamine, R ⁸⁴ represents a hydrogen atom or a linear or branched alkyl group having 1 to 16 carbon atoms. When ^R84 has more than 16 carbon atoms, the proportion of the functional group in the molecule is small, and the antioxidant ability may be weakened. The alkyl group of R ^84, specifically, for example, a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, heptyl group, octyl group, nonyl group, decyl group, undecyl group, dodecyl group, A tridecyl group, a tetradecyl group, a pentadecyl group, a hexadecyl group and the like (these alkyl groups may be linear or branched).

Among the compounds represented by the general formula (38), when ^R84 is an alkyl group, a branched alkyl group having 8 to 16 carbon atoms is preferable because of its excellent solubility of the oxidation product itself in the base oil. Further, a branched alkyl group having 8 to 16 carbon atoms derived from an oligomer of an olefin having 3 or 4 carbon atoms is more preferable. Specific examples of the olefin having 3 or 4 carbon atoms include propylene, 1-butene, 2-butene, and isobutylene. From the viewpoint of excellent solubility of the oxidation product itself in the base oil, Propylene or isobutylene is preferred.

When the phenyl-α-naphthylamine represented by the above general formula (38) is used as the amine-based antioxidant, R ⁸⁴ is a branched octyl group derived from a hydrogen molecule or a dimer of isobutylene, and 3 amounts of propylene. Branched nonyl group derived from the body, branched dodecyl group derived from the trimer of isobutylene, branched dodecyl group derived from the tetramer of propylene, or branched pentadecyl derived from the pentamer of propylene A branched octyl group derived from a hydrogen molecule or a dimer of isobutylene, a branched dodecyl group derived from a trimer of isobutylene or a branched dodecyl group derived from a tetramer of propylene. Particularly preferred.

When Np-alkylphenyl-α-naphthylamine in which R ⁸⁴ is an alkyl group is used as the phenyl-α-naphthylamine represented by the general formula (38), as this Np-alkylphenyl-α-naphthylamine, A commercially available product may be used. In addition, phenyl-α-naphthylamine and a halogenated alkyl compound having 1 to 16 carbon atoms, an olefin having 2 to 16 carbon atoms, or an olefin oligomer having 2 to 16 carbon atoms and phenyl-α-naphthylamine using a Friedel-Crafts catalyst. It can be easily synthesized by reacting. Specific examples of Friedel-Crafts catalysts in this case include metal halides such as aluminum chloride, zinc chloride, and iron chloride; sulfuric acid, phosphoric acid, phosphorus pentoxide, boron fluoride, acidic clay, activated clay, etc. Or an acidic catalyst.

On the other hand, in the general formula (39) representing p, p′-dialkyldiphenylamine, R ⁸⁵ and R ⁸⁶ each independently represents an alkyl group having 1 to 16 carbon atoms. When one or both of R ⁸⁵ and R ⁸⁶ are hydrogen atoms, they themselves may precipitate as sludge due to oxidation. On the other hand, when the number of carbon atoms exceeds 16, the proportion of functional groups in the molecule is small. Therefore, the antioxidant ability may be weakened.

Specific examples of R ⁸⁵ and R ⁸⁶ include, for example, methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group, undecyl group, dodecyl group, A tridecyl group, a tetradecyl group, a pentadecyl group, a hexadecyl group and the like (these alkyl groups may be linear or branched). Among these, as R ⁸⁵ and R ⁸⁶ , a branched alkyl group having 3 to 16 carbon atoms is preferable from the viewpoint of excellent solubility of its own oxidation product with respect to the lubricating base oil, and further having 3 or 4 carbon atoms. A branched alkyl group having 3 to 16 carbon atoms derived from an olefin or an oligomer thereof is more preferable. Specific examples of the olefin having 3 or 4 carbon atoms include propylene, 1-butene, 2-butene, and isobutylene, but the oxidation product itself has excellent solubility in a lubricating base oil. From the viewpoint, propylene or isobutylene is preferable.

When p, p′-dialkyldiphenylamine represented by the above general formula (39) is used as the amine antioxidant, R ⁸⁵ and R ⁸⁶ are isopropyl groups derived from propylene, and tert-butyl derived from isobutylene. A branched hexyl group derived from a propylene dimer, a branched octyl group derived from an isobutylene dimer, a branched nonyl group derived from a propylene trimer, and an isobutylene trimer Branched dodecyl groups derived from propylene tetramers or branched pentadecyl groups derived from propylene pentamers are particularly preferred, tert-butyl groups derived from isobutylene, propylene Branched hexyl group derived from the dimer of glycan, branched octyl group derived from the dimer of isobutylene A branched nonyl group derived from propylene trimer, is a branched dodecyl group derived from a tetramer of a branched dodecyl or propylene derived from a trimer of isobutylene particularly preferred.

  A commercially available product may be used as p, p'-dialkyldiphenylamine represented by the general formula (39). Further, similarly to the phenyl-α-naphthylamine represented by the general formula (38), diphenylamine and a halogenated alkyl compound having 1 to 16 carbon atoms, an olefin having 2 to 16 carbon atoms, an olefin having 2 to 16 carbon atoms, or these These oligomers and diphenylamine can be easily synthesized using a Friedel-Crafts catalyst. As the Friedel-Crafts catalyst at this time, specifically, for example, metal halides and acidic catalysts listed in the synthesis of phenyl-α-naphthylamine are used.

  In the present invention, one type selected from phenyl-α-naphthylamine represented by the general formula (38) and p, p′-dialkyldiphenylamine represented by the general formula (39) may be used alone, or Two or more compounds may be used in combination.

  The content of the amine-based antioxidant in the lubricating oil composition for machine tools of the present invention is preferably 3% by mass or less, more preferably 2% by mass or less, and still more preferably 1% by mass or less, based on the total amount of the composition. is there. Even if the content of the amine-based antioxidant exceeds 3% by mass, there is no further improvement effect of thermal / oxidative stability and sludge inhibiting property commensurate with the content, and solubility in the lubricating base oil. Tends to be insufficient. On the other hand, the lower limit of the content of the amine antioxidant is preferably 0.01% by mass or more, more preferably 0.1% by mass or more, and further preferably 0.2% by mass or more, based on the total amount of the composition. is there. When the content of the amine-based antioxidant is less than 0.01% by mass, the effect of improving the heat / oxidation stability and sludge suppression by the addition tends to be insufficient.

  Moreover, the lubricating oil composition for machine tools of this invention can contain an oil-based agent from the point of a frictional characteristic improvement.

  Examples of oil agents include ester oil agents, alcohol oil agents, carboxylic acid oil agents, ether oil agents, amine oil agents, amide oil agents, and the like.

  The ester oily agent is obtained by reacting an alcohol and a carboxylic acid. The alcohol may be a monohydric alcohol or a polyhydric alcohol. The carboxylic acid may be a monobasic acid or a polybasic acid.

  As the monohydric alcohol constituting the ester oil-based agent, those having 1 to 24 carbon atoms, preferably 1 to 12 carbon atoms, more preferably 1 to 8 carbon atoms are usually used. May be saturated, saturated or unsaturated. 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 pentanol, and linear Linear or branched hexanol, linear or branched heptanol, linear or branched octanol, linear or branched nonanol, linear or branched decanol, linear or branched Undecanol, linear or branched dodecanol, linear or branched tridecanol, linear or branched tetradecanol, linear or branched pentadecanol, linear or branched hexadecane Decanol, linear or branched heptadecanol, linear or branched octadecanol, linear or branched nonadecanol, linear or branched icosa Lumpur, linear or branched Hen'ikosanoru, linear or branched Torikosanoru, such as linear or branched tetracosanol, and mixtures thereof.

  Moreover, as a polyhydric alcohol which comprises ester oiliness agent, a 2-10 valence is used normally, Preferably a 2-6 valence is used. Specific examples of the 2 to 10 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, etc.), trimethylolalkanes (trimethylolethane, trimethylolpropane, trimethylolbutane, etc.) and their 2- to 8-mer, pentaerythritol and their 2- to 4-mer, 1,2,4- Butanetriol, 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 That.

  Among these polyhydric alcohols, 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, trimethylol Methylol butane and the like, 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 preferable. Even more preferred are ethylene glycol, propylene glycol, neopentyl glycol, glycerin, trimethylol ethane, trimethylol propane, pentaerythritol, sorbitan, and mixtures thereof.

  The alcohol constituting the ester oily agent may be a monohydric alcohol or a polyhydric alcohol as described above, but is preferably a polyhydric alcohol from the viewpoint of superior friction characteristics.

  Of the acids constituting the ester oily agent, as the monobasic acid, a fatty acid having 2 to 24 carbon atoms is usually used. The fatty acid may be linear or branched, and may not be saturated. It may be saturated. Specifically, for example, acetic acid, propionic acid, linear or branched butanoic acid, linear or branched pentanoic acid, linear or branched hexanoic acid, linear or branched heptane Acid, linear or branched octanoic acid, linear or branched nonanoic acid, linear or branched decanoic acid, linear or branched undecanoic acid, linear or branched dodecane Acid, linear or branched tridecanoic acid, linear or branched tetradecanoic acid, linear or branched pentadecanoic acid, linear or branched hexadecanoic acid, linear or branched heptadecane Acid, linear or branched octadecanoic acid, linear or branched hydroxyoctadecanoic acid, linear or branched nonadecanoic acid, linear or branched icosanoic acid, linear or branched Henicosanoic acid, linear or branched Saturated fatty acids such as cosanoic acid, linear or branched tricosanoic acid, linear or branched tetracosanoic acid, acrylic acid, linear or branched butenoic acid, linear or branched pentenoic acid, Linear or branched hexenoic acid, linear or branched heptenoic acid, linear or branched octenoic acid, linear or branched nonenoic 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 heptadecenoic acid, linear or branched octadecenoic acid, linear or branched hydroxyoctadecenoic acid, linear or branched nonadecene Acid, linear or branched Unsaturated fatty acids such as cocenoic acid, linear or branched heicosenoic acid, linear or branched docosenoic acid, linear or branched tricosenoic acid, linear or branched tetracosenoic acid, and the like And the like.

  Examples of the polybasic acid include dibasic acid and trimellitic acid, and dibasic acid is preferable. The dibasic acid may be a chain dibasic acid or a cyclic dibasic acid. Further, in the case of a chain dibasic acid, it may be either linear or branched, and may be either saturated or unsaturated. The chain dibasic acid is preferably a chain dibasic acid having 2 to 16 carbon atoms. 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 heptanedioic acid, linear or branched octanedioic acid, linear or branched nonane diacid Acid, linear or branched decanedioic acid, linear or branched undecanedioic acid, linear or branched dodecanedioic 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 heptenedioic acid Linear or branched octene diacid, linear or branched nonene diacid, linear or branched Branched decenedioic acid, linear or branched undecenedioic acid, linear or branched dodecenedioic acid, linear or branched tridecenedioic acid, linear or branched tetradecenedioic acid And linear or branched heptacene diacid, linear or branched hexadecene diacid, and mixtures thereof. Examples of the cyclic dibasic acid include 1,2-cyclohexanedicarboxylic acid, 4-cyclohexene-1,2-dicarboxylic acid, and aromatic dicarboxylic acid. Among these, a chain dibasic acid is preferable from the viewpoint of stability.

  The acid constituting the ester oily agent may be a monobasic acid or a polybasic acid as described above, but a monobasic acid is preferred from the viewpoint that the effect of improving friction characteristics is more excellent.

The combination of the alcohol and the acid in the ester-based oily agent is arbitrary and is not particularly limited, and examples thereof include esters by the following combinations (i) to (vii).
(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 Ester (v) monohydric alcohol, mixture of polyhydric alcohol and polybasic acid (vi) mixed ester of polyhydric alcohol with monobasic acid, polybasic acid (vii) monohydric alcohol A mixed ester of a mixture of a polyhydric alcohol and a monobasic acid or polybasic acid.

  Each of the esters (ii) to (vii) may be a complete ester in which all of the hydroxyl groups of the polyhydric alcohol or the carboxyl groups of the polybasic acid are esterified, and some of them are hydroxyl groups or carboxyl groups. The remaining partial ester may be used, but the partial ester is preferable from the viewpoint of the effect of improving the friction characteristics.

  Among the esters (i) to (vii) above, (ii) an ester of a polyhydric alcohol and a monobasic acid is preferable. This ester has a very high effect of improving friction characteristics.

  In the ester (ii), the number of carbon atoms of the monobasic acid is preferably 10 or more, more preferably 12 or more, and still more preferably 14 or more, from the viewpoint of improving the frictional properties.

  In addition, the number of carbon atoms of the monobasic acid is preferably 28 or less, more preferably 26 or less, and still more preferably 24 or less, from the viewpoint of preventing precipitation. Examples of such esters include glycerin monooleate and sorbitan monooleate.

  Examples of the alcohol oil-based agent include alcohols exemplified in the description of the ester oil-based agent. The number of carbon atoms in the alcohol oil-based agent is preferably 6 or more, more preferably 8 or more, and most preferably 10 or more, from the viewpoint of improving frictional characteristics. Moreover, since there exists a possibility that it may precipitate easily when carbon number is too large, 24 or less are preferable, 20 or less are more preferable, and 18 or less are the most preferable.

  The carboxylic acid oily agent may be a monobasic acid or a polybasic acid. Examples of such carboxylic acids include monobasic acids and polybasic acids exemplified in the description of the ester oily agent. Among these, a monobasic acid is preferable from the viewpoint of improving the friction characteristics. In addition, the number of carbon atoms of the carboxylic acid oil-based agent is preferably 6 or more, more preferably 8 or more, and most preferably 10 or more from the viewpoint of improving the friction characteristics. Moreover, since there exists a possibility that it may precipitate easily when carbon number of a carboxylic acid oiliness agent is too large, 24 or less are preferable, 20 or less are more preferable, and 18 or less are the most preferable.

  Examples of ether oily agents include etherified products of 3 to 6 aliphatic polyhydric alcohols, bimolecular condensates or trimolecular condensates of 3 to 6 aliphatic polyhydric alcohols, and the like.

  The etherified product of a 3-6 valent aliphatic polyhydric alcohol is represented, for example, by the following general formulas (40)-(45).

［式中、Ｒ^８７〜Ｒ^１１１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１〜１８の直鎖状もしくは分岐鎖状のアルキル基、アリル基、アラルキル基、−（Ｒ^aＯ）_n−Ｒ^b（Ｒ^aは炭素数２〜６のアルキレン基、Ｒ^bは炭素数１〜２０のアルキル基、アリル基、アラルキル基、ｎは１〜１０の整数を示す）で示されるグリコールエーテル残基を示す。］

[Wherein, R ^{87 to} R ¹¹¹ may be the same or different, and each represents a hydrogen atom or a linear or branched alkyl group having 1 to 18 carbon atoms, an allyl group, an aralkyl group, — (R ^a O ) _N -R ^b (R ^a is an alkylene group having 2 to 6 carbon atoms, R ^b is an alkyl group having 1 to 20 carbon atoms, an allyl group, an aralkyl group, and n is an integer of 1 to 10) Indicates an ether residue. ]

Specific examples of the 3-6 valent aliphatic polyhydric alcohol include glycerin, trimethylolpropane, erythritol, pentaerythritol, arabitol, sorbitol, mannitol and the like. R ^{87 to} R ¹¹¹ in the general formulas (40) to (45) are methyl group, ethyl group, n-propyl group, isopropyl group, various butyl groups, various pentyl groups, various hexyl groups, various heptyl groups, Various octyl groups, various nonyl groups, various decyl groups, various undecyl groups, various dodecyl groups, various tridecyl groups, various tetradecyl groups, various pentadecyl groups, various hexadecyl groups, various heptadecyl groups, various octadecyl groups, phenyl groups, benzyl groups, etc. Is mentioned. The etherified product also includes a partially etherified product in which a part of R ^{87 to} R ¹¹¹ is a hydrogen atom.

  As the etherified product of a bimolecular condensate or a trimolecular condensate of a 3-6 valent aliphatic polyhydric alcohol, the same or different condensates of the compounds represented by the general formulas (40) to (45) are used. Is mentioned. For example, a bimolecular condensate and a trimolecular condensate of alcohol represented by the general formula (40) are represented by the general formulas (46) and (47), respectively. Moreover, the etherified product of the alcohol bimolecular condensate and trimolecular condensate represented by the general formula (43) is represented by the general formulas (48) and (49), respectively.

［式中、Ｒ^８７〜Ｒ^８９及びＲ^９７〜Ｒ^１００はそれぞれ式（４０）中のＲ^８７〜Ｒ^８９及び式（４３）中のＲ^９７〜Ｒ^１００と同一の定義内容を示す。］

Wherein ^indicates the same definition as ^R 97 ^{to R 100} of the ^R 87 ^{to R 89} and the formula (43) in R 87 ^{to R 89} and ^R 97 ^{to R 100} each equation (40) in. ]

  Specific examples of the bimolecular condensate and trimolecular condensate of 3 to 6-valent aliphatic polyhydric alcohol include diglycerin, ditrimethylolpropane, dipentaerythritol, disorbitol, triglycerin, tritrimethylolpropane, and tripentaerythritol. And trisorbitol.

  Specific examples of the ether oil agents represented by the general formulas (40) to (45) include glycerol trihexyl ether, glycerol dimethyl octyl triether, glycerol di (methyloxyisopropylene) dodecyl triether, Diphenyl octyl triether, di (phenyloxy isopropylene) dodecyl triether of glycerol, trihexyl ether of trimethylol propane, dimethyl octyl triether of trimethylol propane, di (methyloxy isopropylene) dodecyl triether of trimethylol propane, Tetrahexyl ether of pentaerythritol, trimethyloctyl tetraether of pentaerythritol, tri (methyloxyisopropylene) dodecylte of pentaerythritol Laether, Hexapropyl ether of sorbitol, Tetramethyloctylpentaether of sorbitol, Hexa (methyloxyisopropylene) ether of sorbitol, Tetrabutyl ether of diglycerol, Dimethyldioctyltetraether of diglycerol, Tri (methyloxyisopropylene) ) Dodecyl tetraether, triglycerin pentaethyl ether, triglycerin trimethyldioctylpentaether, triglycerin tetra (methyloxyisopropylene) decylpentaether, ditrimethylolpropane tetrabutylether, ditrimethylolpropane dimethyldioctyltetraether, Tri (methyloxyisopropylene) dodecyltetrae of ditrimethylolpropane Ter, tritrimethylolpropane pentaethyl ether, tritrimethylolpropane trimethyldioctylpentaether, tritrimethylolpropane tetra (methyloxyisopropylene) decylpentaether, dipentaerythritol hexapropylether, dipentaerythritol pentamethyloctylhexa Ether, dipentaerythritol hexa (methyloxyisopropylene) ether, tripentaerythritol octapropyl ether, tripentaerythritol pentamethyloctyl hexaether, tripentaerythritol hexa (methyloxyisopropylene) ether, disorbitol octater Methyl dioctyl deca ether, disorbitol deca (methyloxyisopropylate) N) ether.

  Among these, diphenyl octyl triether of glycerin, di (methyloxyisopropylene) dodecyl triether of trimethylolpropane, tetrahexyl ether of pentaerythritol, hexapropyl ether of sorbitol, dimethyldioctyl tetraether of diglycerin, triglycerin Tetra (methyloxyisopropylene) decyl pentaether, hexapropyl ether of dipentaerythritol, and pentamethyloctyl hexaether of tripentaerythritol are preferred.

  Examples of the oily agent that can be used in the present invention include amine oily agents and amide oily agents in addition to the above.

  Examples of the amine oily agent include monoamines, polyamines, and alkanolamines. Among these, monoamines are preferable from the viewpoint of improving friction characteristics.

Specific examples of monoamines include monomethylamine, dimethylamine, trimethylamine, monoethylamine, diethylamine, triethylamine, monopropylamine (including all isomers), dipropylamine (including all isomers), Propylamine (including all isomers), monobutylamine (including all isomers), dibutylamine (including all isomers), tributylamine (including all isomers), monopentylamine (all including all isomers) Including isomers), dipentylamine (including all isomers), tripentylamine (including all isomers), monohexylamine (including all isomers), dihexylamine (including all isomers) ), Monoheptylamine (including all isomers), diheptylamine (including all isomers) ), Monooctylamine (including all isomers), dioctylamine (including all isomers), monononylamine (including all isomers), monodecylamine (including all isomers), monoundecyl (Including all isomers), monododecylamine (including all isomers), monotridecylamine (including all isomers), monotetradecylamine (including all isomers), monopentadecyl Amine (including all isomers), monohexadecylamine (including all isomers), monoheptadecylamine (including all isomers), monooctadecylamine (including all isomers), mononona Decylamine (including all isomers), monoicosylamine (including all isomers), monohenicosylamine (including all isomers), monodocosyl Min (including all isomers), monotricosylamine (including all isomers), dimethyl (ethyl) amine, dimethyl (propyl) amine (including all isomers), dimethyl (butyl) amine (all Isomers), dimethyl (pentyl) amine (including all isomers), dimethyl (hexyl) amine (including all isomers), dimethyl (heptyl) amine (including all isomers), dimethyl ( Octyl) amine (including all isomers), dimethyl (nonyl) amine (including all isomers), dimethyl (decyl) amine (including all isomers), dimethyl (undecyl) amine (all isomers) ), Dimethyl (dodecyl) amine (including all isomers), dimethyl (tridecyl) amine (including all isomers), dimethyl (tetradecyl) ) Amine (including all isomers), dimethyl (pentadecyl) amine (including all isomers), dimethyl (hexadecyl) amine (including all isomers), dimethyl (heptadecyl) amine (all isomers) ), Dimethyl (octadecyl) amine (including all isomers), dimethyl (nonadecyl) amine (including all isomers), dimethyl (icosyl) amine (including all isomers), dimethyl (henicosyl) Alkylamines such as amines (including all isomers), dimethyl (tricosyl) amine (including all isomers);
Monovinylamine, divinylamine, trivinylamine, monopropenylamine (including all isomers), dipropenylamine (including all isomers), tripropenylamine (including all isomers), monobutenylamine (Including all isomers), dibutenylamine (including all isomers), tributenylamine (including all isomers), monopentenylamine (including all isomers), dipentenylamine (all isomers) ), Tripentenylamine (including all isomers), monohexenylamine (including all isomers), dihexenylamine (including all isomers), monoheptenylamine (all isomers) ), Diheptenylamine (including all isomers), monooctenylamine (including all isomers), dioctenylamine (Including all isomers), monononenylamine (including all isomers), monodecenylamine (including all isomers), monoundecenyl (including all isomers), monododecenylamine (Including all isomers), monotridecenylamine (including all isomers), monotetradecenylamine (including all isomers), monopentadecenylamine (including all isomers), Monohexadecenylamine (including all isomers), monoheptadecenylamine (including all isomers), monooctadecenylamine (including all isomers), monononadecenylamine (all isomers) ), Monoicosenylamine (including all isomers), monohenicocenylamine (including all isomers), monodocosenylamine (including all isomers), Trichoderma cell (including all isomers) cycloalkenyl amines alkenyl amines, such as;
Dimethyl (vinyl) amine, dimethyl (propenyl) amine (including all isomers), dimethyl (butenyl) amine (including all isomers), dimethyl (pentenyl) amine (including all isomers), dimethyl ( Hexenyl) amine (including all isomers), dimethyl (heptenyl) amine (including all isomers), dimethyl (octenyl) amine (including all isomers), dimethyl (nonenyl) amine (all isomers) ), Dimethyl (decenyl) amine (including all isomers), dimethyl (undecenyl) amine (including all isomers), dimethyl (dodecenyl) amine (including all isomers), dimethyl (tridecenyl) Amine (including all isomers), dimethyl (tetradecenyl) amine (including all isomers), dimethyl (pen Decenyl) amine (including all isomers), dimethyl (hexadecenyl) amine (including all isomers), dimethyl (heptadecenyl) amine (including all isomers), dimethyl (octadecenyl) amine (all isomers) ), Dimethyl (nonadecenyl) amine (including all isomers), dimethyl (icosenyl) amine (including all isomers), dimethyl (henicosenyl) amine (including all isomers), dimethyl (tricosenyl) Monoamines having alkyl and alkenyl groups such as amines (including all isomers);
Monobenzylamine, (1-phenyltyl) amine, (2-phenylethyl) amine (also known as monophenethylamine), dibenzylamine, bis (1-phenethyl) amine, bis (2-phenylethylene) amine (also known as diphenethylamine) Aromatic substituted alkylamines such as
C5-C16 cycloalkylamines such as monocyclopentylamine, dicyclopentylamine, tricyclopentylamine, monocyclohexylamine, dicyclohexylamine, monocycloheptylamine, dicycloheptylamine;
Monoamines having an alkyl group and a cycloalkyl group, such as dimethyl (cyclopentyl) amine, dimethyl (cyclohexyl) amine, dimethyl (cycloheptyl) amine;
(Methylcyclopentyl) amine (including all substituted isomers), bis (methylcyclopentyl) amine (including all substituted isomers), (dimethylcyclopentyl) amine (including all substituted isomers), bis (dimethylcyclopentyl) ) Amine (including all substituted isomers), (ethylcyclopentyl) amine (including all substituted isomers), bis (ethylcyclopentyl) amine (including all substituted isomers), (methylethylcyclopentyl) amine ( All substituted isomers included), bis (methylethylcyclopentyl) amine (including all substituted isomers), (diethylcyclopentyl) amine (including all substituted isomers), (methylcyclohexyl) amine (all substituted isomers) Isomers), bis (methylcyclohexyl) amine (all substituted isomers) ), (Dimethylcyclohexyl) amine (including all substituted isomers), bis (dimethylcyclohexyl) amine (including all substituted isomers), (ethylcyclohexyl) amine (including all substituted isomers), bis (Ethylcyclohexyl) amine (including all substituted isomers), (Methylethylcyclohexyl) amine (including all substituted isomers), (Diethylcyclohexyl) amine (including all substituted isomers), (Methylcycloheptyl) ) Amine (including all substituted isomers), bis (methylcycloheptyl) amine (including all substituted isomers), (dimethylcycloheptyl) amine (including all substituted isomers), (ethylcycloheptylamine) (Including all substituted isomers), (methylethylcycloheptyl) amine (all substituted isomers) And alkyl cycloalkylamines such as (diethylcycloheptyl) amine (including all substituted isomers), etc. The monoamine also includes monoamines derived from fats and oils such as beef tallow amine. It is.

  Among the above-mentioned monoamines, alkylamine, monoamine having an alkyl group and an alkenyl group, monoamine having an alkyl group and a cycloalkyl group, cycloalkylamine and alkylcycloalkylamine are particularly preferable from the viewpoint of improving frictional properties, alkylamine, A monoamine having an alkyl group and an alkenyl group is more preferable.

  Although there is no restriction | limiting in particular about carbon number of a monoamine, It is preferable that it is 8 or more from the point of rust prevention property, and it is more preferable that it is 12 or more. Further, from the viewpoint of improving the friction characteristics, it is preferably 24 or less, and more preferably 18 or less.

  Further, the number of hydrocarbon groups bonded to the nitrogen atom in the monoamine is not particularly limited, but is preferably 1 or 2 and more preferably 1 from the viewpoint of improving the frictional characteristics.

  Amide oil-based agents include nitrogen-containing compounds such as amine compounds containing only fatty acids having 6 to 30 carbon atoms or acid chlorides thereof, ammonia, hydrocarbon groups having 1 to 8 carbon atoms or hydroxyl group-containing hydrocarbon groups in the molecule. And amides obtained by reacting.

  The fatty acid here may be a linear fatty acid or a branched fatty acid, and may be a saturated fatty acid or an unsaturated fatty acid. The carbon number is 6-30, preferably 9-24.

  Specific examples of the fatty acid include heptanoic acid, octanoic acid, nonanoic acid, decanoic acid, undecanoic acid, dodecanoic acid, tridecanoic acid, tetradecanoic acid, pentadecanoic acid, hexadecanoic acid, heptadecanoic acid, octadecanoic acid, nonadecanoic acid, Saturated fatty acids such as icosanoic acid, henicosanoic acid, docosanoic acid, tricosanoic acid, tetracosanoic acid, pentacosanoic acid, hexacosanoic acid, heptacosanoic acid, octacosanoic acid, nonacosanoic acid and triacontyl group (these saturated fatty acids may be linear or branched) ); Heptenoic acid, octenoic acid, nonenoic acid, decenoic acid, undecenoic acid, dodecenoic acid, tridecenoic acid, tetradecenoic acid, pentadecenoic acid, hexadecenoic acid, heptadecenoic acid, octadecenoic acid (including oleic acid), nonadecenoic acid, icosenic acid, Henicosenoic acid Unsaturated fatty acids such as docosenoic acid, tricosenoic acid, tetracosenoic acid, pentacosenoic acid, hexacosenoic acid, heptacosenoic acid, octacosenoic acid, nonacenoic acid, triacontenoic acid (these unsaturated fatty acids may be linear or branched, The position of the heavy bond is also arbitrary); but the linear fatty acids derived from lauric acid, myristic acid, palmitic acid, stearic acid, oleic acid, various fats and oils (coconut oil fatty acid etc.) A mixture of linear fatty acid and branched fatty acid synthesized by the oxo method or the like is preferably used.

  Specific examples of the nitrogen-containing compound to be reacted with the fatty acid include ammonia; monomethylamine, monoethylamine, monopropylamine, monobutylamine, monopentylamine, monohexylamine, monoheptylamine, monooctylamine, dimethylamine, Alkylamines such as methylethylamine, diethylamine, methylpropylamine, ethylpropylamine, dipropylamine, methylbutylamine, ethylbutylamine, propylbutylamine, dibutylamine, dipentylamine, dihexylamine, diheptylamine, dioctylamine, etc. May be chain or branched); monomethanolamine, monoethanolamine, monopropanolamine, monobutanolamine, monopentanolamine, monohexene Noramine, monoheptanolamine, monooctanolamine, monononanolamine, dimethanolamine, methanolethanolamine, diethanolamine, methanolpropanolamine, ethanolpropanolamine, dipropanolamine, methanolbutanolamine, ethanolbutanolamine, propanolbutanolamine, di Examples thereof include alkanolamines such as butanolamine, dipentanolamine, dihexanolamine, diheptanolamine and dioctanolamine (the alkanol group may be linear or branched); and mixtures thereof.

  Specific examples of fatty acid amides include lauric acid amide, lauric acid diethanolamide, lauric acid monopropanolamide, myristic acid amide, myristic acid diethanolamide, myristic acid monopropanolamide, palmitic acid amide, palmitic acid diethanolamide, and palmitic acid. Acid monopropanolamide, stearic acid amide, stearic acid diethanolamide, stearic acid monopropanolamide, oleic acid amide, oleic acid diethanolamide, oleic acid monopropanolamide, coconut oil fatty acid amide, coconut oil fatty acid diethanolamide, coconut oil fatty acid mono Propanolamide, C12-13 synthetic mixed fatty acid amide, C12-13 synthetic mixed fatty acid diethanolamide, C12-13 synthetic blend Fatty acid mono-propanol amides, and mixtures thereof are particularly preferred.

  Among the oily agents, preferred are a polyhydric alcohol partial ester and an aliphatic amide from the viewpoint of the effect of improving frictional properties.

  The content of the oil-based agent in the lubricating oil composition for machine tools of the present invention is arbitrary, but is preferably 0.01% by mass or more, more preferably, based on the total amount of the composition, from the viewpoint of excellent effect of improving friction characteristics. Is 0.05 mass% or more, more preferably 0.1 mass% or more. In addition, the content is preferably 10% by mass or less, more preferably 7.5% by mass or less, and further preferably 5% by mass or less, based on the total amount of the composition, from the viewpoint of precipitation prevention.

  Moreover, the lubricating oil composition for machine tools of this invention can contain the triazole and / or its derivative which have a structure represented by following formula (50) from the point of a heat | fever and oxidation stability improvement.

  In the formula (50), two broken lines represent the same or different substituents substituted on the triazole ring, preferably a hydrocarbon group, respectively, and both can be bonded to each other to form a cyclic group, for example, a condensed benzene ring.

  A preferable compound as triazole and / or a derivative thereof is benzotriazole and / or a derivative thereof.

  As said benzotriazole, the compound represented by following formula (51) is illustrated.

  Examples of the benzotriazole derivative include alkylbenzotriazole represented by the following general formula (52) and (alkyl) aminoalkylbenzotriazole represented by the general formula (53).

In the above formula (52), R ¹¹² represents a linear or branched alkyl group having 1 to 4 carbon atoms, preferably a methyl group or an ethyl group, and x is an integer of 1 to 3, preferably 1. Or 2 is shown. Examples of R ¹¹² include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, and a tert-butyl group. As the alkylbenzotriazole represented by the formula (52), a compound in which R ¹¹² is a methyl group or an ethyl group and x is 1 or 2 is particularly preferable from the viewpoint of excellent heat and antioxidant properties. Examples thereof include methylbenzotriazole (tolyltriazole), dimethylbenzotriazole, ethylbenzotriazole, ethylmethylbenzotriazole, diethylbenzotriazole, and mixtures thereof.

In the above formula (53), R ¹¹³ represents a linear or branched alkyl group having 1 to 4 carbon atoms, preferably a methyl group or an ethyl group, R ¹¹⁴ represents a methylene group or an ethylene group, and R ¹¹⁵ And R ¹¹⁶ may be the same or different and each represents a hydrogen atom or a linear or branched alkyl group having 1 to 18 carbon atoms, preferably a linear or branched alkyl group having 1 to 12 carbon atoms. And y represents an integer of 0 to 3, preferably 0 or 1. Examples of ^R113 include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, and a tert-butyl group. As R ¹¹⁵ and R ¹¹⁶ , for example, a hydrogen atom, methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group, straight chain or A branched pentyl group, 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, Linear or branched undecyl group, linear or branched dodecyl group, linear or branched tridecyl group, linear or branched tetradecyl group, linear or branched pentadecyl group, linear or branched Alkyl groups such as a hexadecyl group, a linear or branched heptadecyl group, and a linear or branched octadecyl group.

As the (alkyl) aminobenzotriazole represented by the above formula (53), R ¹⁰⁴ is a methyl group, y is 0 or 1, and R ¹⁰⁵ is a methylene group or the Dialkylaminoalkylbenzotriazole, dialkylaminoalkyltolyltriazole or a mixture thereof, which is an ethylene group and R ¹⁰⁶ and R ¹⁰⁷ are linear or branched alkyl groups having 1 to 12 carbon atoms, are preferably used. Examples of these dialkylaminoalkylbenzotriazoles include dimethylaminomethylbenzotriazole, diethylaminomethylbenzotriazole, di (linear or branched) propylaminomethylbenzotriazole, and di (linear or branched) butylaminomethylbenzotriazole. , Di (straight or branched) pentylaminomethylbenzotriazole, di (straight or branched) hexylaminomethylbenzotriazole, di (straight or branched) heptylaminomethylbenzotriazole, di (straight or branched) ) Octylaminomethylbenzotriazole, di (straight or branched) nonylaminomethylbenzotriazole, di (straight or branched) decylaminomethylbenzotriazole, di (straight or branched) undecylaminomethylbenzotriazole, (Linear or branched) dodecylaminomethylbenzotriazole; dimethylaminoethylbenzotriazole, diethylaminoethylbenzotriazole, di (linear or branched) propylaminoethylbenzotriazole, di (linear or branched) butylaminoethylbenzo Triazole, di (straight or branched) pentylaminoethylbenzotriazole, di (straight or branched) hexylaminoethylbenzotriazole, di (straight or branched) heptylaminoethylbenzotriazole, di (straight or branched) Branch) Octylaminoethylbenzotriazole, Di (straight or branched) nonylaminoethylbenzotriazole, Di (straight or branched) decylaminoethylbenzotriazole, Di (straight or branched) undecylaminoethylbenzotriazole , Di (linear or straight Branched) dodecylaminoethyl benzotriazole; dimethylaminomethyltolyltriazole, diethylaminomethyltolyltriazole, di (linear or branched) propylaminomethyltolyltriazole, di (straight or branched) butylaminomethyltolyltriazole, di ( Linear or branched) pentylaminomethyltolyltriazole, di (linear or branched) hexylaminomethyltolyltriazole, di (straight or branched) heptylaminomethyltolyltriazole, di (linear or branched) octylamino Methyltolyltriazole, di (linear or branched) nonylaminomethyltolyltriazole, di (straight or branched) decylaminomethyltolyltriazole, di (straight or branched) undecylaminomethyltolyltriazole, di (direct Chain or branch) Silaminomethyltolyltriazole; dimethylaminoethyltolyltriazole, diethylaminoethyltolyltriazole, di (linear or branched) propylaminoethyltolyltriazole, di (linear or branched) butylaminoethyltolyltriazole, di (linear or Branched) pentylaminoethyltolyltriazole, di (straight or branched) hexylaminoethyltolyltriazole, di (straight or branched) heptylaminoethyltolyltriazole, di (straight or branched) octylaminoethyltolyltriazole , Di (linear or branched) nonylaminoethyl tolyl triazole, di (linear or branched) decylaminoethyl tolyl triazole, di (linear or branched) undecylaminoethyl tolyl triazole, di (linear or branched) Branch) Dodecylamino Tilt Lil triazole; or mixtures thereof.

  The content of triazole and / or its derivative in the lubricating oil composition for machine tools of the present invention is arbitrary, but is preferably 0.001% by mass or more, more preferably 0.005% by mass or more, based on the total amount of the composition. It is. When the content of triazole and / or its derivative is less than 0.001% by mass, the effect of improving thermal and oxidation stability due to the addition tends to be insufficient. Further, the content of triazole and / or a derivative thereof is preferably 1.0% by mass or less, more preferably 0.5% by mass or less, based on the total amount of the composition. When it exceeds 1.0 mass%, the further improvement effect of the heat | fever and oxidation stability only commensurate with content cannot be acquired, and there exists a possibility that it may become economically disadvantageous.

  In addition, the lubricating oil composition for machine tools of the present invention has a viscosity index other than a rust inhibitor, a metal deactivator, and the above-described dispersed viscosity index improver, if necessary, for the purpose of further improving the performance. Various additives represented by an improver, a cleaning dispersant, a pour point depressant, an antifoaming agent, and the like may be contained alone or in combination.

  Specific examples of rust inhibitors include metal soaps such as fatty acid metal salts, lanolin fatty acid metal salts, and oxidized wax metal salts; partial alcohol esters such as sorbitan fatty acid esters; esters such as lanolin fatty acid esters; Examples thereof include sulfonates such as calcium sulfonate and barium sulfonate; oxidized wax; amines; phosphoric acid; In the present invention, one or two or more compounds arbitrarily selected from these rust inhibitors can be contained in any amount, but the content is usually based on the total amount of the composition. It is desirable that it is 0.01-1 mass%.

  Specific examples of the metal deactivator include imidazole compounds in addition to the above benzotriazole compounds. In the present invention, one kind or two or more kinds of compounds arbitrarily selected from these metal deactivators can be contained in any amount, but the content thereof is usually the composition. It is desirable that it is 0.001-1 mass% on the basis of the total amount.

  In addition, as the viscosity index improver other than the dispersion type viscosity index improver, specifically, a copolymer of one or two or more monomers selected from various methacrylic esters or a hydrogenated product thereof, ethylene-α -Olefin copolymers (Examples of α-olefins include propylene, 1-butene, 1-pentene, etc.) or hydrogenated products thereof, polyisobutylene or hydrogenated products thereof, styrene-diene hydrogenated copolymers, and polyalkylstyrenes And so-called non-dispersion type viscosity index improvers. Examples of the detergent dispersant other than the dispersion type viscosity index improver include alkenyl succinimide, sulfonate, salicylate, and phenate. One or two or more compounds arbitrarily selected from these viscosity index improvers and detergent dispersants can be contained in any amount, but the content is usually based on the total amount of the composition. It is desirable that it is 0.01-10 mass%.

  Specific examples of the pour point depressant include copolymers of one or more monomers selected from various acrylic esters and methacrylic esters or hydrogenated products thereof. One or two or more compounds arbitrarily selected from these pour point depressants can be contained in any amount, but the content is usually 0.01% based on the total amount of the composition. It is desirable that it is ˜5% by mass.

  Specific examples of the antifoaming agent include silicones such as dimethyl silicone and fluorosilicone. In the present invention, one or two or more compounds arbitrarily selected from these antifoaming agents can be contained in any amount, and the content is usually based on the total amount of the composition. It is desirable that it is 0.0001-0.05 mass%.

  The lubricating oil composition for machine tools of the present invention having the above-described configuration can achieve all of friction characteristics, stick-slip reduction and thermal / oxidation stability at a high level in a balanced manner. This is very useful in terms of performance.

  The lubricating oil composition for machine tools of the present invention is particularly suitably used for lubricating a sliding guide surface of a machine tool, and is also suitably used for lubricating various bearings, gears, hydraulic systems and the like of machine tools.

  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.

[Manufacture of lubricating base oil]
(Base oil 1)
The fraction separated by distillation under reduced pressure in the step of refining the solvent refined base oil was subjected to hydrogenation after solvent extraction with furfural, and then dewaxed with a methyl ethyl ketone-toluene mixed solvent. The wax removed during the solvent dewaxing (hereinafter referred to as “WAX1”) was used as a raw material for the lubricating base oil. Table 1 shows the properties of WAX1.

Next, in the presence of a hydrocracking catalyst, WAX1 was hydrocracked under the conditions of a hydrogen partial pressure of 5 MPa, an average reaction temperature of 340 ° C., and LHSV 0.8 hr ⁻¹ . As the hydrocracking catalyst, a catalyst in which nickel and molybdenum were supported on an amorphous silica / alumina carrier was used in a sulfurized state.

  Next, the cracked product obtained by the above hydrocracking was distilled under reduced pressure to obtain a 20% by volume lubricating oil fraction with respect to the raw material oil. The lubricating oil fraction was subjected to solvent dewaxing using a methyl ethyl ketone-toluene mixed solvent under conditions of a solvent / oil ratio of 2 times and a filtration temperature of -30 ° C. to obtain a target lubricating base oil (hereinafter referred to as “base oil 1”). ").

(Base oil 2)
700 g of zeolite and 300 g of an alumina binder were mixed and kneaded and molded into a cylindrical shape having a diameter of 1/16 inch (about 1.6 mm) and a height of 8 mm. The obtained molded body was fired at 480 ° C. for 2 hours to obtain a carrier. By impregnating this carrier with an aqueous solution of dichlorotetraamineplatinum (II) in an amount of 1.0% by mass of the carrier in terms of platinum, drying at 125 ° C. for 2 hours, and baking at 380 ° C. for 1 hour, The desired catalyst was obtained.

Next, the obtained catalyst was charged into a fixed bed flow reactor, and hydrocracking / hydroisomerization of feedstock containing paraffinic hydrocarbons was performed using this reactor. In this step, FT wax (hereinafter referred to as “WAX2”) having a paraffin content of 95% by mass and having a carbon number distribution of 20 to 80 was used as the raw material oil. Table 2 shows the properties of WAX2. The hydrocracking conditions were a hydrogen pressure of 3.5 MPa, a reaction temperature of 340 ° C., LHSV 1.5 h ^−1, and a fraction (decomposition product) having a boiling point of 370 ° C. or lower with respect to the raw material was 25 mass% (decomposition rate 25 %) Was obtained.

  Next, a lubricating oil fraction was obtained by distillation under reduced pressure of the cracked / isomerized product oil obtained in the hydrocracking / hydroisomerization step. The lubricating oil fraction was subjected to solvent dewaxing using a methyl ethyl ketone-toluene mixed solvent under the conditions of a solvent / oil ratio of 3 times and a filtration temperature of -30 ° C. to obtain a target lubricating base oil (hereinafter referred to as “base oil 2”). ").

(Base oil 3-5)
The fraction separated by distillation under reduced pressure in the step of refining the solvent refined base oil was subjected to hydrogenation after solvent extraction with furfural, and then dewaxed with a methyl ethyl ketone-toluene mixed solvent. A wax obtained by further deoiling the slack wax removed during the solvent dewaxing (hereinafter referred to as “WAX3”) was used as a raw material for the lubricant base oil. Table 3 shows the properties of WAX3.

Next, WAX3 was hydrocracked in the presence of a hydrocracking catalyst under the conditions of a hydrogen partial pressure of 5.5 MPa, an average reaction temperature of 340 ° C., and LHSV 0.8 hr ⁻¹ . As the hydrocracking catalyst, a catalyst in which nickel and molybdenum were supported on an amorphous silica / alumina carrier was used in a sulfurized state.

  Next, the cracked product obtained by the above hydrocracking was distilled under reduced pressure to obtain a 20% by volume lubricating oil fraction with respect to the raw material oil. About this lubricating oil fraction, solvent dewaxing was performed using a methyl ethyl ketone-toluene mixed solvent under the conditions of a solvent / oil ratio of 2 times and a filtration temperature of -30 ° C. to obtain a lubricating base oil (hereinafter referred to as “base oil 3”). .)

  Table 4 shows various properties and performance evaluation test results of the base oils 1 to 3. Table 5 shows various properties and performance evaluation test results of conventional high viscosity index base oils (base oil 4, base oil 5 and base oil 6).

[Examples 1 to 21, Comparative Examples 1 to 8]
In Examples 1-21, the lubricating oil composition for machine tools which has a composition shown to Tables 6-8 using the base oils 1-3 and the additive shown below was prepared. Moreover, in Comparative Examples 1-8, the lubricating oil composition for machine tools which has a composition shown to Tables 9-10 was prepared using the base oils 1-6 and the additive shown below.
(Compounds containing phosphorus and / or sulfur as constituent elements)
A1: oleyl acid phosphate A2: oleylamine salt of oleyl acid phosphate A3: tricresyl phosphate A4: sulfurized ester (sulfur content: 11.4% by mass)
A5: Sulfurized lard (sulfur content: 11.0% by mass)
(Other additives)
B1: oleic acid B2: 2,6-di-tert-butyl-p-cresol.

  Next, the following evaluation tests were carried out on the lubricating oil compositions for machine tools of Examples 1 to 21 and Comparative Examples 1 to 8.

[Thermal and oxidation stability test]
The sludge generation inhibitory property of each lubricating oil composition was evaluated in accordance with JIS K 2540-1989 “Lubricating oil thermal stability test method”. That is, 45 g of the lubricating oil composition was weighed into a 50 ml beaker, and a copper catalyst and an iron catalyst were placed therein, left in an air constant temperature bath at 140 ° C. for 72 hours, and then the amount of sludge in the lubricating oil composition was measured. . The amount of generated sludge was determined by diluting the tested lubricating oil composition with n-hexane, filtering it with a 0.8 μm membrane filter, and measuring the weight of the collected material. As the copper catalyst and the iron catalyst, the catalyst used in the turbine oil oxidation stability test (JIS K 2514) was cut into 8 volumes (about 3.5 cm in length). The obtained results are shown in Tables 6-10.

[Frictional property evaluation test]
FIG. 1 is a schematic configuration diagram showing a friction coefficient measurement system used in a friction characteristic evaluation test. In FIG. 1, a table 1 and a movable jig 4 connected via a load cell 5 are arranged on a bed 6, and a heavyweight 9 as a substitute for a processing tool is arranged on the table 1. Yes. Both the table 1 and the bed 6 are made of cast iron. The movable jig 4 has a bearing portion, and the bearing portion is connected to the A / C servo motor 2 via the feed screw 3. By operating the feed screw 3 by the A / C servometer 2, the movable jig 4 can be reciprocated in the axial direction of the feed screw 3 (arrow direction in the figure). Further, the load cell 5 is electrically connected to the computer 7, and the computer 7 and the A / C servometer 2 are electrically connected to the control plate 8, thereby controlling the reciprocating motion of the movable jig 4 and the table 1 and the movable jig. The load between 4 can be measured.

  In such a friction coefficient measurement system, a lubricating oil composition is dropped on the upper surface of the bed 6, and after adjusting the surface pressure between the table 1 and the bed 6 to 200 kPa by selecting the table weight 9, the feed rate is 1.2 mm. The movable jig 4 was reciprocated with a feed length of 15 mm / min. The load between the table 1 and the movable jig 4 at this time is measured by a load cell 5 (load meter), and the friction coefficient of the guide surface (table 1 / bed 6 = cast iron / cast iron) based on the obtained measurement value. Asked. In addition, the said test was done after running in 3 times. The friction coefficient of each lubricating oil composition is shown in Tables 6-12.

(Stick slip reduction evaluation test)
FIG. 2 is a schematic configuration diagram showing a stick-slip reduction evaluation apparatus (TE-77 tester manufactured by Print & Partners). In the apparatus shown in FIG. 2, a lower test piece 12, an upper test piece 11, and an elastic body 10 are laminated in this order on a support base 110, and the elastic body 10 is pressed while pressing the test pieces 11 and 12 together with a predetermined load. The test pieces 11 and 12 are slid by reciprocating (sliding) along the surface of the support table 110. And the friction coefficient between the test pieces 11 and 12 is calculated | required by measuring the load added to the test pieces 11 and 12 by the load detector 13 in the case of this sliding. FIG. 3 is a graph showing an example of the correlation between the friction coefficient obtained by the above operation and time. Δμ in the figure indicates the amplitude of the friction coefficient.

  In accordance with the method described in the literature (Tribology Society Tribology Conference Proceedings Tokyo 1999-5 D17) except that the test piece and conditions were improved for the evaluation of the lubricant for the sliding guide surface using such an apparatus. Δμ when each lubricating oil composition was interposed between the test pieces 11 and 12 was measured. Specifically, JIS G 4051 S45C was used for each of the test pieces 11 and 12, chloroprene rubber was used for the elastic body 10, and the test was performed at an average sliding speed of 0.3 mm / s and a load of 250N. Stick slip reduction was evaluated as “no stick slip” when Δμ was less than 0.02, and “with stick slip” when amplitude Δμ was 0.02 or more. The obtained results are shown in Tables 6-10.

It is a schematic block diagram which shows typically the friction coefficient measuring system used in the Example. It is a schematic block diagram which shows typically the stick slip reduction evaluation apparatus used in the Example. It is a graph which shows an example of the correlation with the friction coefficient obtained using the apparatus of FIG. 2, and time.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Table, 2 ... A / C servo meter, 3 ... Feed screw, 4 ... Movable jig, 5 ... Load cell, 6 ... Bed, 7 ... Computer, 8 ... Control panel, 9 ... Heavyweight, 10 ... Elastic body, 11 ... upper test piece, 12 ... lower test piece, 13 ... load detector, 110 ... support base.

Claims (1)

Lubricating oil fractions obtained by subjecting crude oil to atmospheric distillation and / or vacuum distillation can be subjected to solvent degreasing, solvent extraction, hydrocracking, solvent dewaxing, catalytic dewaxing, hydrorefining, sulfuric acid washing or clay treatment. It is at least one lubricating base oil selected from paraffinic mineral oil, normal paraffinic base oil and isoparaffinic base oil, which are refined by combining one of these refining treatments alone or in combination of two or more. ,% _{C A} of 2 or _{less,% C} P /% C _N is 6 or more 35 or less, and the lubricating oil base oil is an iodine value of 2.5 or less,
A lubricating oil composition for machine tools, comprising at least one selected from phosphoric acid monoesters and salts thereof, phosphoric acid diesters and salts thereof, phosphoric acid triesters, sulfurized fats and oils and sulfurized esters .

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