JP2010235851A - Lubricating oil composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lubricating oil composition capable of achieving satisfactory wear resistance and oxidation stability. <P>SOLUTION: The lubricating oil composition contains: a lubricating base oil, which has ≥90 mass% saturated component, a cyclic saturated component accounting for ≤60 mass% of the saturated component and ≥100 viscosity index; and the alkanoyl borate shown by general formula (1) (wherein R<SP>1</SP>and R<SP>2</SP>may be the same or different from each other and are each a hydrogen atom or a 1-30C alkyl or alkenyl group). Even when a metal-free, phosphorus-free and sulfur-free additive are used, the lubricating oil composition can be achieved satisfactory wear resistance and oxidation stability. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a lubricating oil composition.

  In recent years, there has been an increasing interest in global environmental problems, and in particular, reduction of metallic additives contained in exhaust gas including diesel engine oil has been demanded. On the other hand, in the industrial field, additives containing phosphorus and sulfur are added as antiwear and antioxidant agents, which are directly emitted into the atmosphere or when used oil is discarded. Cause various problems such as processing problems. Therefore, development of a base oil with a sulfur content reduced as much as possible, and studies on additives that do not contain phosphorus content, metal content, and sulfur content have been made (see Patent Documents 1 to 10).

JP-A-4-36391 JP 63-223094 A JP-A-8-302378 JP 9-003463 A JP-T-2006-502298 JP-T-2002-503754 Japanese Patent Laid-Open No. 2001-226381 JP 2005-60527 A JP 2005-290158 A JP 2008-106199 A

  The reduction in the sulfur content of the base oil can be achieved to some extent by limiting the raw materials and the production method. However, with respect to the additive, from the viewpoint of maintaining the original function of the additive, the metal content, the phosphorus content, or The limit is to reduce the sulfur content, and problems still remain in the practical use of metal-free, phosphorus-free, and sulfur-free anti-wear additives.

  Recently, it has been confirmed that boron improves wear resistance and oxidation stability, and a method of containing or dispersing boron in an existing additive has been studied. There is room.

  The present invention has been made in view of such circumstances, and a lubricating oil composition capable of achieving sufficient wear resistance and oxidation stability using an additive free of metal, phosphorus and sulfur. The purpose is to provide goods.

［式（１）中、Ｒ^１及びＲ^２はそれぞれ同一でも異なっていてもよく、それぞれ水素又は炭素数１〜３０のアルキル基又はアルケニル基を示す。］ In order to solve the above problems, the present invention provides a lubricating base oil having a saturated content of 90% by mass or more, a cyclic saturated content accounting for 60% by mass or less, and a viscosity index of 100 or more, and the following general formula ( A lubricating oil composition comprising the alkanoyl borate represented by 1) is provided.

[In Formula (1), R ¹ and R ² may be the same or different, and each represents hydrogen or an alkyl group or alkenyl group having 1 to 30 carbon atoms. ]

The lubricating base oil preferably has a urea adduct value of 4% by mass or less.
The urea adduct value as used in the present invention is measured by the following method. 100 g of weighed sample oil (lubricating base oil) is placed in a round bottom flask, 200 g of urea, 360 ml of toluene and 40 ml of methanol are added and stirred at room temperature for 6 hours. As a result, white granular crystals are produced as urea adducts in the reaction solution. The reaction solution is filtered through a 1 micron filter to collect the produced white granular crystals, and the obtained crystals are washed 6 times with 50 ml of toluene. The recovered white crystals are put in a flask, 300 ml of pure water and 300 ml of toluene are added, and the mixture is stirred at 80 ° C. for 1 hour. The aqueous phase is separated and removed with a separatory funnel, and the toluene phase is washed three times with 300 ml of pure water. A desiccant (sodium sulfate) is added to the toluene phase for dehydration, and then toluene is distilled off. The ratio (mass percentage) of the urea adduct thus obtained to the sample oil is defined as the urea adduct value.

  Moreover, the viscosity index as used in the present invention and the kinematic viscosity at 40 ° C. or 100 ° C. described later mean a viscosity index measured according to JIS K 2283-1993 and a kinematic viscosity at 40 ° C. or 100 ° C., respectively. .

  In the present invention, a lubricating base oil is used in which the saturated component, the non-cyclic saturated component in the saturated component, and the viscosity index satisfy the above requirements. The lubricating base oil preferably has a urea adduct value of 4% by mass or less. In addition, the alkanoyl borate represented by the general formula (1) has sufficient wear resistance and oxidation stability when blended in the lubricating base oil, in spite of a metal-free additive that does not contain a metal as a constituent element. It is possible to impart sex.

  The inventors of the present invention have analyzed by using GC and NMR that the main component of the urea adduct is a normal paraffin and an isoparaffin urea adduct having 6 or more carbon atoms from the end of the main chain to the branch position. Confirm that there is.

  In the present invention, the lubricating base oil is hydrogenated so that the raw material oil containing normal paraffin has a urea adduct value of 4% by mass or less and a viscosity index of 100 or more. A lubricating base oil obtained by the process of cracking / hydroisomerization is preferred. Further, the feedstock oil preferably contains 50% by mass or more of slack wax obtained by solvent dewaxing of the lubricating base oil.

  As described above, according to the lubricating oil composition of the present invention, it is possible to achieve sufficient wear resistance and oxidation stability using a metal-free additive.

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

  The lubricating oil composition of the present invention comprises a lubricating base oil (hereinafter referred to as “lubricant according to the present invention”) having a saturated content of 90% by mass or more, a cyclic saturated content of 60% by mass or less, and a viscosity index of 100 or more. "Oil base oil").

  In addition, the urea adduct value of the lubricating base oil according to the present invention is preferably 4% by mass or less, more preferably 3 as described above, from the viewpoint of improving the low temperature viscosity characteristics without impairing the viscosity-temperature characteristics. 0.5% by mass or less, more preferably 3% by mass or less, and further preferably 2.5% by mass or less. Further, the urea adduct value of the lubricating base oil may be 0% by mass.

  The viscosity index of the lubricating base oil according to the present invention needs to be 100 or more as described above from the viewpoint of viscosity-temperature characteristics, preferably 110 or more, more preferably 120 or more, still more preferably 130 or more. Especially preferably, it is 140 or more.

  When producing the lubricating base oil according to the present invention, a normal oil containing normal paraffin or a wax containing normal paraffin can be used. The raw material oil may be either mineral oil or synthetic oil, or may be a mixture of two or more of these. Further, the content of normal paraffin in the raw material oil is preferably 50% by mass or more, more preferably 70% by mass or more, still more preferably 80% by mass or more, more preferably 90% by mass, based on the total amount of the raw material oil. Especially preferably, it is 95 mass% or more, Most preferably, it is 97 mass% or more.

  Moreover, it is preferable that the raw material oil used by this invention is a wax containing raw material which boils in the lubricating oil range prescribed | regulated to ASTMD86 or ASTM D2887. The wax content of the raw material oil is preferably 50% by mass or more and 100% by mass or less based on the total amount of the raw material oil. The wax content of the raw material can be measured by analytical techniques such as nuclear magnetic resonance spectroscopy (ASTM D5292), correlated ring analysis (ndM) method (ASTM D3238), solvent method (ASTM D3235) and the like.

  Examples of the wax-containing raw material include oils derived from solvent refining methods such as raffinate, partial solvent dewaxed oil, dewaxed oil, distillate, reduced pressure gas oil, coker gas oil, slack wax, foots oil, and fisher Examples include Tropsch wax, and among these, slack wax and Fischer-Tropsch wax are preferable.

  Slack waxes are typically derived from hydrocarbon feedstocks by solvent or propane dewaxing. Slack wax may contain residual oil, which can be removed by deoiling. Foots oil corresponds to deoiled slack wax.

  Fischer-Tropsch wax is produced by a so-called Fischer-Tropsch synthesis method.

  Furthermore, you may use a commercial item as raw material oil containing normal paraffin. Specific examples include Paraflint 80 (hydrogenated Fischer-Tropsch wax) and Shell MDS Waxy Raffinate (hydrogenated and partially isomerized middle distillate synthetic waxy raffinate).

  Moreover, the raw material oil derived from solvent extraction is obtained by sending a high-boiling petroleum fraction from atmospheric distillation to a vacuum distillation apparatus and solvent-extracting the distillation fraction from this apparatus. The residue from the vacuum distillation may be denitrified. In the solvent extraction method, aromatic components are dissolved in the extraction phase while leaving more paraffinic components in the raffinate phase. Naphthene is partitioned into the extraction phase and the raffinate phase. As the solvent for solvent extraction, phenol, furfural, N-methylpyrrolidone and the like are preferably used. By controlling the solvent / oil ratio, the extraction temperature, the method of contacting the distillate to be extracted with the solvent, etc., the degree of separation between the extraction phase and the raffinate phase can be controlled. Furthermore, a bottom fraction obtained from a fuel oil hydrocracking apparatus may be used as a raw material by using a fuel oil hydrocracking apparatus having higher hydrogenation resolution.

The raw material oil is subjected to hydrocracking / hydroisomerization so that the urea adduct value of the material to be treated is 4% by mass or less and the viscosity index is 100 or more. Such a lubricating base oil can be obtained. The hydrocracking / hydroisomerization step is not particularly limited as long as the urea adduct value and the viscosity index of the obtained workpiece satisfy the above conditions. The preferred hydrocracking / hydroisomerization step in the present invention is:
A first step of hydrotreating a raw oil containing normal paraffin using a hydrotreating catalyst;
A second step of hydrodewaxing the object to be treated obtained in the first step using a hydrodewaxing catalyst;
The to-be-processed object obtained by a 2nd process is equipped with the 3rd process of hydrotreating using a hydrotreating catalyst.

  In the conventional hydrocracking / hydroisomerization, a hydrotreating step is provided before the hydrodewaxing step for the purpose of desulfurization / denitrogenation for the prevention of poisoning of the hydrodewaxing catalyst. There is a thing. On the other hand, in the first step (hydrotreating step) in the present invention, a part of the normal paraffin in the feedstock (for example, about 10% by mass, preferably in the previous stage of the second step (hydrodewaxing step), preferably 1 to 10% by mass), and desulfurization / denitrogenation is possible in the first step, but the purpose is different from that of the conventional hydrotreatment. Providing such a first step is preferable for ensuring that the urea adduct value of the article to be processed (lubricant base oil) obtained after the third step is 4% by mass or less.

  Examples of the hydrogenation catalyst used in the first step include a catalyst containing a Group 6 metal, a Group 8-10 metal, and a mixture thereof. Preferred metals include nickel, tungsten, molybdenum, cobalt, and mixtures thereof. The hydrogenation catalyst can be used in a form in which these metals are supported on a refractory metal oxide support, and the metal is usually present as an oxide or sulfide on the support. When a metal mixture is used, the metal may be present as a bulk metal catalyst in which the amount of metal is 30% by mass or more based on the total amount of the catalyst. Examples of the metal oxide support include oxides such as silica, alumina, silica-alumina, and titania, and among these, alumina is preferable. Preferred alumina is γ-type or β-type porous alumina. The amount of metal supported is preferably in the range of 0.5 to 35% by mass based on the total amount of the catalyst. Also, when using a mixture of Group 9-10 metal and Group 6 metal, either Group 9 or Group 10 metal is present in an amount of 0.1-5% by weight, based on the total amount of catalyst, The Group 6 metal is preferably present in an amount of 5 to 30% by mass. Metal loading may be measured by atomic absorption spectroscopy, inductively coupled plasma emission spectroscopy, or other methods specified by ASTM for individual metals.

  The acidity of the metal oxide support can be controlled by adding additives, controlling the nature of the metal oxide support (eg, controlling the amount of silica incorporated into the silica-alumina support), and the like. Examples of additives include halogens, especially fluorine, phosphorus, boron, yttria, alkali metals, alkaline earth metals, rare earth oxides, and magnesia. Cocatalysts such as halogen generally increase the acidity of the metal oxide support, but weakly basic additives such as yttria or magnesia tend to weaken the acidity of such support.

Regarding the hydrotreatment conditions, the treatment temperature is preferably 150 to 450 ° C., more preferably 200 to 400 ° C., the hydrogen partial pressure is preferably 1400 to 20000 kPa, more preferably 2800 to 14000 kPa, and the liquid space velocity (LHSV) is preferably 0.1 to 10 ^-1, more preferably 0.1～5Hr ^-1, a hydrogen / oil ratio is preferably 50~1780m ³ / ^{m 3,} more preferably 89～890M ³ / M ³ . In addition, said conditions are an example and the hydrotreating conditions in the 1st process for the urea adduct value and viscosity index of the to-be-processed object obtained after a 3rd process satisfy | fill the said conditions respectively are a raw material, a catalyst, an apparatus, etc. It is preferable to select appropriately according to the difference.

  The object to be processed after the hydrogenation treatment in the first step may be used as it is in the second step, but the object to be processed is stripped or distilled to generate gas from the object to be processed (liquid product). It is preferable to provide a step of separating and removing the object between the first step and the second step. Thereby, the nitrogen content and sulfur content contained in the object to be treated can be reduced to a level without affecting the long-term use of the hydrodewaxing catalyst in the second step. The object of separation and removal by stripping or the like is mainly gaseous foreign matters such as hydrogen sulfide and ammonia, and stripping can be performed by ordinary means such as a flash drum and a fractionator.

  Moreover, when the conditions of the hydrogenation treatment in the first step are mild, there is a possibility that the remaining polycyclic aromatics may pass through depending on the raw materials used. It may be removed by purification.

  Further, the hydrodewaxing catalyst used in the second step may contain either crystalline or amorphous material. Examples of the crystalline material include molecular sieves having a 10- or 12-membered ring passage mainly composed of aluminosilicate (zeolite) or silicoaluminophosphate (SAPO). Specific examples of zeolite include ZSM-22, ZSM-23, ZSM-35, ZSM-48, ZSM-57, ferrierite, ITQ-13, MCM-68, MCM-71 and the like. Moreover, ECR-42 is mentioned as an example of an aluminophosphate. Examples of molecular sieves include zeolite beta and MCM-68. Among these, it is preferable to use 1 type, or 2 or more types selected from ZSM-48, ZSM-22, and ZSM-23, and ZSM-48 is particularly preferable. The molecular sieve is preferably in the hydrogen form. Although the reduction of the hydrodewaxing catalyst can occur in situ at the time of hydrodewaxing, a hydrodewaxing catalyst that has been subjected to a reduction treatment in advance may be subjected to hydrodewaxing.

  Examples of the amorphous material of the hydrodewaxing catalyst include alumina doped with a group 3 metal, fluorided alumina, silica-alumina, fluorided silica-alumina, silica-alumina, and the like.

  Preferred embodiments of the dewaxing catalyst include those equipped with bifunctional, ie, metal hydrogenation components that are at least one Group 6 metal, at least one Group 8-10 metal, or mixtures thereof. Preferred metals are group 9-10 noble metals such as Pt, Pd or mixtures thereof. The mounting amount of these metals is preferably 0.1 to 30% by mass based on the total amount of the catalyst. Examples of the catalyst preparation and the metal mounting method include an ion exchange method and an impregnation method using a decomposable metal salt.

  When molecular sieves are used, they may be combined with a binder material having heat resistance under hydrodewaxing conditions, or may be without a binder (self-bonding). As binder materials, silica, alumina, silica-alumina, combinations of two components of silica and other metal oxides such as titania, magnesia, tria, zirconia, silica-alumina-tria, silica-alumina-magnesia, etc. Inorganic oxides such as a combination of three components of oxides such as The amount of the molecular sieve in the hydrodewaxing catalyst is preferably 10 to 100% by mass, more preferably 35 to 100% by mass, based on the total amount of the catalyst. The hydrodewaxing catalyst is formed by a method such as spray drying or extrusion. The hydrodewaxing catalyst can be used in a sulfided or non-sulfided form, and a sulfided form is preferred.

Regarding hydrodewaxing conditions, the temperature is preferably 250-400 ° C., more preferably 275-350 ° C., and the hydrogen partial pressure is preferably 791-20786 kPa (100-3000 psig), more preferably 1480-17339 kPa (200- a 2500 psig), liquid hourly space velocity is preferably 0.1 to 10 ^-1, more preferably 0.1~5hr ^-1, a hydrogen / oil ratio is preferably 45~1780m ³ / ^{m 3} (250~10000scf / B), more preferably ^{89~890m 3 / m 3 (500~5000scf /} B). In addition, said conditions are an example and the hydrodewaxing conditions in the 2nd process for the urea adduct value and viscosity index of the to-be-processed object obtained after a 3rd process satisfy | fill the said conditions are a raw material, a catalyst, and an apparatus, respectively. It is preferable to select appropriately according to the difference.

  The object to be treated that has been hydrodewaxed in the second step is subjected to hydrorefining in the third step. Hydrorefining is a form of mild hydrotreating that aims to saturate olefins and residual aromatic compounds by hydrogenation in addition to removal of residual heteroatoms and hues. The hydrorefining in the third step can be carried out in cascade with the dewaxing step.

  The hydrorefining catalyst used in the third step is preferably a metal oxide carrier on which a Group 6 metal, a Group 8-10 metal or a mixture thereof is supported. Preferred metals include noble metals, especially platinum, palladium and mixtures thereof. If a mixture of metals is used, it may be present as a bulk metal catalyst where the amount of metal is 30% by weight or more based on the catalyst. The metal content of the catalyst is preferably 20% by mass or less for non-noble metals and 1% by mass or less for noble metals. The metal oxide support may be either amorphous or crystalline oxide. Specific examples include low acid oxides such as silica, alumina, silica-alumina or titania, and alumina is preferred. From the viewpoint of saturation of the aromatic compound, it is preferable to use a hydrorefining catalyst in which a metal having a relatively strong hydrogenation function is supported on a porous support.

  Preferred hydrorefining catalysts include mesoporous materials belonging to the M41S class or family of catalysts. M41S series catalysts are mesoporous materials with high silica content, and specifically include MCM-41, MCM-48 and MCM-50. Such a hydrorefining catalyst has a pore diameter of 15 to 100 mm, and MCM-41 is particularly preferable. MCM-41 is an inorganic porous non-layered phase having a hexagonal arrangement of uniformly sized pores. The physical structure of MCM-41 is like a bundle of straws where the opening of the straw (cell diameter of the pores) is in the range of 15-100 angstroms. MCM-48 has cubic symmetry, and MCM-50 has a layered structure. MCM-41 can be manufactured with pore openings of different sizes in the mesoporous range. The mesoporous material may have a metal hydrogenation component that is at least one of a Group 8, 9 or 10 metal, and the metal hydrogenation component is preferably a noble metal, particularly a Group 10 noble metal, Pt , Pd or mixtures thereof are most preferred.

Regarding the hydrorefining conditions, the temperature is preferably 150-350 ° C, more preferably 180-250 ° C, the total pressure is preferably 2859-20786 kPa (about 400-3000 psig), and the liquid space velocity is preferably 0. 0.1 to 5 hr ⁻¹ , more preferably 0.5 to ³ hr ⁻¹ , and the hydrogen / oil ratio is preferably 44.5 to 1780 m ³ / m ³ (250 to 10,000 scf / B). In addition, said conditions are an example and the hydrogenation production | generation conditions in the 3rd process for the urea adduct value and viscosity index of the to-be-processed object obtained after a 3rd process satisfy | fill the said conditions respectively are the difference of a raw material or a processing apparatus. It is preferable to select appropriately according to.

  Moreover, about the to-be-processed object obtained after a 3rd process, you may separate and remove a predetermined component by distillation etc. as needed.

  In the lubricating base oil according to the present invention obtained by the above production method, the other properties are not particularly limited as long as the urea adduct value and the viscosity index satisfy the above conditions, respectively, but the lubricating base oil according to the present invention is It is preferable that the following conditions are further satisfied.

  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 oil base oil. Moreover, the ratio of the cyclic | annular saturated part which occupies for the said saturated part becomes like this. Preferably it is 0.1-60 mass%, More preferably, it is 0.5-50 mass%, More preferably, it is 1-30 mass%, Most preferably, it is 5-20. % By mass. Viscosity-temperature characteristics and thermal / oxidative stability can be achieved by satisfying the above conditions for the content of the saturated component and the ratio of the cyclic saturated component in the saturated component, respectively. When the additive represented by the general formula (1) is blended, the additive function is expressed at a higher level while the additive is sufficiently stably dissolved and retained in the lubricating base oil. Can be made. Furthermore, when the content of the saturated component and the ratio of the cyclic saturated component in the saturated component satisfy the above conditions, the friction characteristics of the lubricating base oil itself can be improved, and as a result, the friction reducing effect is improved. As a result, energy saving can be improved.

  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 additive represented by General formula (1) is mix | blended with lubricating base oil as the ratio of the cyclic | annular saturated part which occupies for a saturated part is less than 0.1 mass%, dissolution of the said additive is carried out. Therefore, the effective amount of the additive dissolved and held in the lubricating base oil is lowered, and the function of the additive tends to be unable to be obtained effectively. Furthermore, when the ratio of the cyclic saturated component in the saturated component exceeds 60% by mass, the effectiveness of the additive tends to be reduced when the additive is blended with the lubricating base oil.

  In the present invention, the ratio of the cyclic saturated component in the saturated component being 0.1 to 60% by mass is equivalent to the non-cyclic saturated component in the saturated component being 99.9 to 40% by mass. Here, the non-cyclic saturated component includes both normal paraffin and isoparaffin. The proportion of normal paraffin and isoparaffin in the lubricating base oil according to the present invention is not particularly limited, but the proportion of isoparaffin is preferably 40 to 99.9 mass%, more preferably 50, based on the total amount of lubricating oil base oil. To 99.9% by mass, more preferably 70 to 99% by mass, and particularly preferably 80 to 99.9% by mass. When the ratio of isoparaffin in the lubricating base oil satisfies the above conditions, the viscosity-temperature characteristics and thermal / oxidative stability can be further improved, and the lubricating base oil is represented by the general formula (1). When the additive to be added is blended, the function of the additive can be expressed at a higher level while the additive is sufficiently stably dissolved and held.

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

  Moreover, the ratio of the cyclic saturated component and the non-cyclic saturated component in the saturated component referred to in the present invention is a naphthene component measured according to ASTM D 2786-91, respectively (measuring object: 1-ring to 6-ring naphthene, unit : Mass%) and alkane content (unit: mass%).

In addition, the ratio of normal paraffin in the lubricating base oil referred to in the present invention is a gas chromatographic analysis of the saturated component separated and fractionated by the method described in ASTM D 2007-93 under the following conditions. This means a value obtained by converting the measured value when the ratio of normal paraffin in the saturated content is identified and quantified, based on the total amount of the lubricating base oil. In the identification and quantification, a normal paraffin mixed sample having 5 to 50 carbon atoms is used as a standard sample, and the normal paraffin occupying the saturated component is the total peak area value of the chromatogram (the peak derived from the diluent). Is obtained as a ratio of the sum of peak area values corresponding to each normal paraffin.
(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)

  Further, the ratio of isoparaffin in the lubricating base oil means a value obtained by converting the difference between the non-cyclic saturated component in the saturated component and the normal paraffin component in the saturated component, based on the total amount of the lubricant base oil. .

  In the method of separating saturated components, or in analyzing the composition 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.

  In the lubricating base oil according to the present invention, when the bottom fraction obtained from the fuel oil hydrocracking apparatus is used as a raw material, the content of the saturated component is 90% by mass or more and occupies the saturated component. The proportion of cyclic saturated component is 30 to 50% by mass, the proportion of non-cyclic saturated component in the saturated component is 50 to 70% by mass, the proportion of isoparaffin in the lubricating base oil is 40 to 70% by mass, and the viscosity index is A base oil of 100 to 135, preferably 120 to 130 can be obtained, and the urea adduct value satisfies the above conditions, so that the effect of the present invention, improvement in low temperature viscosity characteristics and low friction can be achieved. In particular, it is possible to obtain an effect that the low temperature viscosity characteristics can be greatly improved. In the lubricating base oil according to the present invention, when slack wax or Fischer-Tropsch wax, which is a raw material having a high wax content (for example, a normal paraffin content of 50% by mass or more) is used as a raw material, Of 90% by mass or more, the proportion of cyclic saturated component in the saturated component is 0.1 to 40% by mass, the proportion of non-cyclic saturated component in the saturated component is 60 to 99.9% by mass, lubrication A base oil having a ratio of isoparaffin in the oil base oil of 60 to 99.9% by mass and a viscosity index of 100 to 170, preferably 135 to 160 can be obtained. The effect of the invention, improvement in low temperature viscosity characteristics and low friction properties can be achieved at the same time, and in particular, a lubricating oil composition having extremely excellent characteristics in high viscosity index and low temperature viscosity characteristics can be obtained. .

  The aromatic content in the lubricating base oil according to the present invention is preferably 5% by mass or less, more preferably 0.05 to 3% by mass, and still more preferably 0.1 to 3% by mass, based on the total amount of the lubricating base oil. 1% by mass, particularly preferably 0.1 to 0.5% by mass. 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. Further, the lubricating base oil according to the present invention may not contain an aromatic component, but the solubility of the additive is further improved by setting the aromatic content to 0.05% by mass or more. Can be increased.

  In addition, content of an aromatic content here 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.

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 98, and particularly preferably 90 to 97. If the% C _p of the lubricating base oil is less than 80, the viscosity-temperature characteristics, thermal / oxidative stability, and friction characteristics tend to be reduced, and when the additive is added to the lubricating base oil The effectiveness of the additive tends to decrease. Further, when the% C _p value of the lubricating base oil exceeds 99, the additive solubility will tend to be lower.

Moreover,% _{C N} of the lubricating base oil according to the present invention is preferably 20 or less, more preferably 15 or less, more preferably 1 to 12, particularly preferably 3 to 10. If the% C _N value of the lubricating base oil exceeds 20, the viscosity - temperature characteristic, heat and oxidation stability and frictional properties will tend to be reduced. Moreover, when% _CN is less than 1, the solubility of the additive tends to decrease.

Moreover,% _{C A} of the lubricating base oil according to the present invention is preferably 0.7 or less, more preferably 0.6 or less, more preferably 0.1 to 0.5. When% C _A of the lubricating base oil exceeds 0.7, the viscosity - temperature characteristic, heat and oxidation stability and frictional properties will tend to be reduced. 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.

Furthermore, the ratio of the lubricating base% in oil _{C P} and% _{C N} of the present _invention,% C is preferably P /% _{C N} is 7 or more, more preferably 7.5 or more, More preferably, it is 8 or more. When% C _P /% _CN is less than 7, viscosity-temperature characteristics, thermal / oxidative stability and friction characteristics tend to be reduced, and further when an additive is blended in the lubricating base oil. The effectiveness of the additive tends to decrease. _{Moreover,% C} P /% C _N is preferably 200 or less, more preferably 100 or less, more preferably 50 or less, particularly preferably 25 or less. By setting% C _P /% _CN to 200 or less, the solubility of the additive can be further increased.

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.

  The iodine value of the lubricating base oil of the present invention is preferably 0.5 or less, more preferably 0.3 or less, still more preferably 0.15 or less, and less than 0.01. However, it is preferably 0.001 or more, more preferably 0.05 or more, from the viewpoint of small effects that are commensurate with it and economic efficiency. By setting the iodine value of the lubricating base oil to 0.5 or less, the thermal and oxidation stability can be dramatically improved. In addition, the iodine value as used in the field of this invention means the iodine value measured by the indicator titration method of JIS K0070 "the acid value of a chemical product, the saponification value, the iodine value, the hydroxyl value, and the unsaponification value."

  Further, the content of sulfur in the lubricating base oil according to the present invention depends on the content of sulfur in 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 lubricating base oil and microwax obtained in the refinement process, further improvements in thermal and oxidation stability and reduction of sulfur are required. Therefore, the sulfur content is preferably 10 ppm by mass or less, more preferably 5 ppm by mass or less, and even more preferably 3 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.

Moreover, the kinematic viscosity at 100 ° C. of the lubricating base oil according to the present invention is preferably 1 to 50 mm ² / s, more preferably ² to 10 mm ² / s, and more preferably 2.5 to 8 mm ² / s. . When the kinematic viscosity at 100 ° C. of the lubricating base oil is less than the lower limit, 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 the upper limit, the yield is low, and it is difficult to increase the decomposition rate even when heavy wax is used as a raw material. This is not preferable.

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. For example, the kinematic viscosity of the lubricating base oil at 100 ° C. is 3.7-4. When it is within the range of 4 mm ² / s, the CCS viscosity of the lubricating base oil at −35 ° C. is preferably 3200 mPa · s or less, more preferably 2000 mPa · s or less, and further preferably 1600 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 ) at 15 ° C. of the lubricating base oil according to the present invention depends on the viscosity grade of the lubricating base oil, but is not more than the value of ρ represented by the following formula (1), that is, ρ It is preferable that ₁₅ ≦ ρ.
ρ = 0.0025 × kv100 + 0.816 (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, in the case of a lubricating base oil having a kinematic viscosity at 100 ° C. in the range of 3.7 to 4.4 mm ² / s, ρ ₁₅ is preferably 0.84 or less, more preferably 0.83 or less. is there.

  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 = 4.3 × kv100 + 100 (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, in the case of a lubricating base oil having a kinematic viscosity at 100 ° C. in the range of 3.7 to 4.4 mm ² / s, the AP is preferably 110 ° C. or higher, more preferably 118 ° 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, in the case of a lubricating base oil having a kinematic viscosity at 100 ° C. in the range of 3.7 to 4.4 mm ² / s. The NOACK evaporation amount is preferably 6% by mass or more, more preferably 8% by mass or more, still more preferably 10 or more, and preferably 20% by mass or less, more preferably 16% by mass or less, still more preferably. It is 14 mass% or less. 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. A lubricating base oil having a desired viscosity range can be obtained by rectifying one or more fractions selected from the fractions in the range.

Regarding the distillation properties of the lubricating base oil according to the present invention, for example, in the case of a lubricating base oil having a kinematic viscosity at 100 ° C. in the range of 3.7 to 4.4 mm ² / s, its initial boiling point (IBP) Is preferably 300 to 400 ° C, more preferably 320 to 390 ° C, and still more preferably 340 to 380 ° C. Moreover, 10% distillation temperature (T10) becomes like this. Preferably it is 360-440 degreeC, More preferably, it is 380-430 degreeC, More preferably, it is 390-420 degreeC. The 50% distillation point (T50) is preferably 400 to 480 ° C, more preferably 410 to 470 ° C, still more preferably 420 to 460 ° C. Moreover, 90% distillation point (T90) becomes like this. Preferably it is 420-500 degreeC, More preferably, it is 430-490 degreeC, More preferably, it is 440-480 degreeC. Moreover, an end point (FBP) becomes like this. Preferably it is 440-520 degreeC, More preferably, it is 450-500 degreeC, More preferably, it is 460-500 degreeC. Moreover, T90-T10 becomes like this. Preferably it is 30-120 degreeC, More preferably, it is 40-100 degreeC, More preferably, it is 50-80 degreeC. Moreover, FBP-IBP becomes like this. Preferably it is 80-200 degreeC, More preferably, it is 90-180 degreeC, More preferably, it is 100-140 degreeC. Moreover, T10-IBP becomes like this. Preferably it is 10-100 degreeC, More preferably, it is 15-70 degreeC, More preferably, it is 20-50 degreeC. Moreover, FBP-T90 becomes like this. Preferably it is 5-80 degreeC, More preferably, it is 10-60 degreeC, More preferably, it is 15-40 degreeC.

  By setting IBP, T10, T50, T90, FBP, T90-T10, FBP-IBP, T10-IBP, and FBP-T90 to the above preferred ranges, further improvement in low-temperature viscosity and further reduction in evaporation loss Is possible. 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.

  The lubricating base oil according to the present invention having the above structure has improved thermal / oxidation stability and wear resistance, and is excellent in viscosity-temperature characteristics, low-temperature viscosity characteristics and friction characteristics, viscosity resistance and The stirring resistance is low. Therefore, by using the lubricating base oil according to the present invention, the heat / oxidation stability and the wear resistance can be improved, and further the energy saving can be achieved. Moreover, when an additive is mix | blended with the lubricating base oil concerning this invention, the function of the said additive can be expressed at a higher level.

  In the lubricating oil composition 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 is used in combination with one or more other base oils. May be. 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. 50% by mass or more is more preferable, and 70% by mass or more is still more preferable.

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 of the present invention contains an alkanoyl borate represented by the following general formula (1).

In the general formula (1), R ¹ and R ² may be the same or different, and each represents hydrogen or an alkyl group or alkenyl group having 1 to 30 carbon atoms. When R ¹ and / or R ² is an alkyl group or an alkenyl group, the alkyl group or alkenyl group may be linear or branched, but is preferably linear. Carbon number of the alkyl group or alkenyl group represented by R ¹ and R ² is 1 to 30, preferably 3 to 18, and more preferably 6 to 10. It is preferable that one or both of R ¹ and R ² is a linear alkyl group having 4 to 10 carbon atoms from the viewpoint of superior wear resistance, and both R ¹ and R ² are carbon atoms from the viewpoint of superior oxidation stability. It is preferably an alkyl group or an alkenyl group having a number of 4 to 18, and since both oxidation stability and wear resistance can be achieved at a higher level, both R ¹ and R ² are alkyl groups having 6 to 10 carbon atoms. Preferably there is. The alkanoyl borate represented by the general formula (1) may be used alone or in combination of two or more.

  In addition, there is no restriction | limiting in particular in the manufacturing method of the alkanoyl borate represented with the said General formula (1), For example, Preferably the glycerol monocarboxylic acid ester by which the hydroxyl group of (alpha) position was esterified and boric acid are 1 0.1-3: 1, preferably 1.5-2.5: 1, more preferably 1.8-2.2: 1 (molar ratio).

  Here, the glycerin monocarboxylic acid ester in which the hydroxyl group at the α-position is esterified is selectively synthesized by a chemical method such as a method in which 1,2-isopropylideneglycerin and fatty acid chloride are reacted and then acid-decomposed. It can also be obtained by separating and purifying only the monoester from a mixture containing mono-, di- and triesters. As a mixture containing the monoester used here, the glycerol partial carboxylic acid ester etc. which were manufactured by direct esterification reaction of carboxylic acid and glycerol, transesterification of fats and oils, and glycerol etc. are mentioned, for example. As a method of separation and purification, it is preferable to purify using a molecular distillation apparatus or a thin film distillation apparatus. Since glycerin has three hydroxyl groups, glycerin carboxylic acid monoester has two isomers. That is, there are those in which the hydroxyl group at the α-position is esterified and those in which the hydroxyl group at the β-position is esterified. However, in the present invention, it is sufficient if the hydroxyl group at the α-position is esterified. It is desirable to use those having a proportion of 50 mol% or more, more preferably 90 mol% or more.

  The carboxylic acid constituting the glycerin monocarboxylic acid ester includes formic acid, acetic acid, propionic acid, butanoic acid (butyric acid), pentanoic acid (valeric acid), isopentanoic acid (isovaleric acid), hexanoic acid (caproic acid), heptane Acid, isoheptanoic acid, octanoic acid (caprylic acid), 2-ethylhexanoic acid, isooctanoic acid, nonanoic acid (pelargonic acid), isononanoic acid, decanoic acid (capric acid), isodecanoic acid, undecanoic acid, isoundecanoic acid, dodecanoic acid (Lauric acid), isododecanoic acid, tridecanoic acid, isotridecanoic acid, tetradecanoic acid (myristic acid), hexadecanoic acid (palmitic acid), octadecanoic acid (stearic acid), isostearic acid, eicosanoic acid (arachic acid), docosanoic acid (behenic acid) ), Tetracosanoic acid (lignoceric acid), f C 1-30 carbon atoms such as sacosanoic acid (serotic acid), octacosanoic acid (montanic acid), 10-undecenoic acid, zomarinic acid, oleic acid, elaidic acid, linoleic acid, linolenic acid, gadrenic acid, erucic acid, ceracolic acid Examples thereof include carboxylic acids having an alkyl group or an alkenyl group.

In the general formula (1), when both R ¹ and R ² are hydrogen, formic acid may be used as the carboxylic acid constituting the glycerin monocarboxylic acid ester in which the α-position hydroxyl group is esterified, When ^one of R ¹ and R ² is hydrogen and the other is an alkyl or alkenyl group having 1 to 30 carbon atoms, the carboxylic acid constituting the glycerin monocarboxylic acid ester in which the hydroxyl group at the α-position is esterified is formic acid And a carboxylic acid having 2 to 30 carbon atoms, and when both R ¹ and R ² are an alkyl group or an alkenyl group having 1 to 30 carbon atoms, a glycerin monocarboxylic acid in which the α-position hydroxyl group is esterified As the carboxylic acid constituting the ester, a carboxylic acid having 2 to 30 carbon atoms may be used.

  In the lubricating oil composition of the present invention, the content of the alkanoyl borate represented by the general formula (1) is preferably 0.01 to 10% by mass, more preferably 0, based on the total amount of the lubricating oil composition. 0.1 to 5% by mass, more preferably 0.5 to 3% by mass. When the content of the alkanoyl borate is less than the lower limit, the wear prevention property tends to be insufficient, and when the content exceeds the upper limit, an effect corresponding to the content cannot be obtained, and Tend to be insufficient.

  In addition to the alkanoyl borate represented by the general formula (1), the lubricating oil composition of the present invention can further contain the following additives.

  Examples of additives that can be preferably added to the lubricating oil composition of the present invention include ashless antioxidants, organometallic antioxidants, viscosity index improvers, friction modifiers, antiwear agents, and corrosion inhibitors. And additives such as a rust inhibitor, a demulsifier, a metal deactivator, an antifoaming agent, and a colorant.

  As the ashless antioxidant, any ashless antioxidants such as phenolic antioxidants and amine antioxidants that are generally used in lubricating oils can be used. By adding the antioxidant, the oxidation stability, the high temperature cleanliness and the base number maintainability of the lubricating oil composition of the present invention can be further enhanced.

  Examples of phenolic antioxidants include 4,4′-methylenebis (2,6-di-tert-butylphenol), 4,4′-bis (2,6-di-tert-butylphenol), 4,4 ′. -Bis (2-methyl-6-tert-butylphenol), 2,2'-methylenebis (4-ethyl-6-tert-butylphenol), 2,2'-methylenebis (4-methyl-6-tert-butylphenol), 4,4′-butylidenebis (3-methyl-6-tert-butylphenol), 4,4′-isopropylidenebis (2,6-di-tert-butylphenol), 2,2′-methylenebis (4-methyl-6) -Nonylphenol), 2,2'-isobutylidenebis (4,6-dimethylphenol), 2,2'-methylenebis (4-methyl) 6-cyclohexylphenol), 2,6-di-tert-butyl-4-methylphenol, 2,6-di-tert-butyl-4-ethylphenol, 2,4-dimethyl-6-tert-butylphenol, 2, 6-di-tert-α-dimethylamino-p-cresol, 2,6-di-tert-butyl-4 (N, N′-dimethylaminomethylphenol), 4,4′-thiobis (2-methyl-6) -Tert-butylphenol), 4,4'-thiobis (3-methyl-6-tert-butylphenol), 2,2'-thiobis (4-methyl-6-tert-butylphenol), bis (3-methyl-4- Hydroxy-5-tert-butylbenzyl) sulfide, bis (3,5-di-tert-butyl-4-hydroxybenzyl) sulfide 2,2′-thio-diethylenebis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], tridecyl-3- (3,5-di-tert-butyl-4-hydroxy Phenyl) propionate, pentaerythrityl-tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], octyl-3- (3,5-di-tert-butyl-4-hydroxyphenyl) ) Propionate, octadecyl-3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate, 3-methyl-5-tert-butyl-4-hydroxyphenyl substituted fatty acid esters and the like are preferable examples. Can do. You may use these in mixture of 2 or more types.

  Examples of amine-based antioxidants include phenyl-α-naphthylamine, alkylphenyl-α-naphthylamine, and dialkyldiphenylamine. You may use these in mixture of 2 or more types.

  In addition, as the organometallic antioxidant, a known organometallic antioxidant containing a metal and having an antioxidant effect can be used, but an organomolybdenum compound and a composition containing sulfur as a constituent element. An organic molybdenum compound (molybdenum-based antioxidant) that does not contain sulfur as an element can be preferably used.

  You may mix | blend the said phenolic antioxidant, amine-type antioxidant, and organometallic antioxidant in combination.

  When the antioxidant is contained in the lubricating oil composition of the present invention, the content is usually 0.01 to 20% by mass, preferably 0.1 to 10% by mass, based on the total amount of the lubricating oil composition. Preferably it is 0.5-5 mass%. When the content exceeds 20% by mass, sufficient performance corresponding to the blending amount cannot be obtained. On the other hand, when the content is less than 0.01% by mass, the effect of improving the base number maintenance property is small. Each is not preferred.

Examples of the viscosity index improver include non-dispersed or dispersed viscosity index improvers. Specifically, non-dispersed or dispersed polymethacrylates, non-dispersed or dispersed ethylene-α-olefin copolymers or hydrides thereof, polyisobutylene or hydrides thereof, styrene-diene hydrogenated copolymers, Examples thereof include styrene-maleic anhydride ester copolymers, polymethacrylate-styrene copolymers, polymethacrylate-olefin copolymers, and polyalkylstyrenes. The weight average molecular weight of these viscosity index improvers is not particularly limited, and is usually 10,000 to 1,000,000, but is preferably 50,000 to 800,000 in terms of further improving fuel economy and excellent shear stability. More preferably, it is 100,000-600,000, Most preferably, it is 150,000-500,000. The PSSI of the viscosity index improver is not particularly limited, but is preferably 1 to 60, more preferably 10 to 40, and still more preferably 20 to 30. Here, PSSI (Permanent Shear Stability Index) is the following calculation using the kinematic viscosity at 100 ° C. before and after the shear stability test (ASTM D6278) and the kinematic viscosity at 100 ° C. of the base oil. formula:
PSSI (%) = {1− (kinematic viscosity after shearing−kinematic viscosity of base oil) / (kinematic viscosity before shearing−kinematic viscosity of base oil)} × 100
Means the index calculated by When the viscosity index improver is contained, the content is usually 0.1 to 20% by mass, preferably 1 to 15% by mass, and more preferably 3 to 10% by mass based on the total amount of the composition.

  Among the friction modifiers, as the ashless friction modifier, any compound usually used as an ashless friction modifier for lubricating oils can be used, for example, a hydrocarbon group having 6 to 30 carbon atoms, preferably An amine compound, an imide compound, a fatty acid ester, a fatty acid amide, a fatty acid, a fatty alcohol, a fatty acid having at least one alkyl group or alkenyl group, particularly a straight-chain alkyl group or straight-chain alkenyl group having 6 to 30 carbon atoms in the molecule Ashless friction modifiers such as aromatic ethers, or various ashless friction modifiers having 1 to 30 carbon atoms and two or more nitrogen atoms. In the present invention, among these ashless friction modifiers, an ashless friction modifier having an ester bond or an amide bond is preferable, and one or more selected from nitrogen, oxygen, and sulfur are used. Ashless friction modifiers having at least 3 atoms are preferred, and ashless friction modifiers selected from compounds having two or more nitrogen atoms and oxygen atoms and / or sulfur atoms, particularly those having an amide bond Is particularly preferred.

  The content of the ashless friction modifier is 0.01 to 10% by mass, preferably 0.1% by mass or more, more preferably 0.3% by mass or more, based on the total amount of the composition. Preferably it is 3 mass% or less, More preferably, it is 2 mass% or less, More preferably, it is 1 mass% or less. When the content of the ashless friction modifier is less than 0.01% by mass, the effect of reducing friction due to the addition tends to be insufficient. When the content exceeds 10% by mass, the effect of an anti-wear additive or the like. Tends to be inhibited, or the solubility of the additive tends to deteriorate.

  Examples of the organometallic friction modifier include organic molybdenum compounds (molybdenum friction modifier) such as molybdenum dithiophosphate and molybdenum dithiocarbamate. The content of the molybdenum-based friction modifier is not particularly limited, but is preferably 0.001 to 0.2% by mass, more preferably 0.01 to 0.1% by mass in terms of molybdenum element based on the total amount of the composition. It is.

  As the antiwear agent, a sulfur antiwear agent, a phosphorus antiwear agent, or the like can be used.

  Examples of the sulfur-based antiwear agent include sulfur-containing compounds such as disulfides, polysulfides, sulfurized olefins, sulfurized fats and oils, sulfurized esters, dithiocarbamate, and zinc dithiocarbamate, and sulfurized fats and oils are most preferable. Among these compounds, the sulfur content in the sulfur-based antiwear agent is preferably 1 to 40% by mass, more preferably 5 to 20% by mass, and still more preferably 5 to 15% by mass. . Even if the sulfur content in the sulfur-based anti-wear agent is too high, the effect of suppressing wear may not be commensurate with the sulfur content, and the base number maintenance performance may be deteriorated. When the sulfur content in the agent is small, the effect of suppressing wear is small.

  Examples of phosphorus-based antiwear agents include phosphoric acid, monothiophosphoric acid, dithiophosphoric acid, trithiophosphoric acid, tetrathiophosphoric acid; phosphoric acid monoester having one hydrocarbon group having 1 to 30 carbon atoms, monothiophosphoric acid monoester, Dithiophosphoric acid monoester, trithiophosphoric acid monoester, tetrathiophosphoric acid monoester; phosphoric acid diester having two hydrocarbon groups having 1 to 30 carbon atoms, monothiophosphoric acid diester, dithiophosphoric acid diester, trithiophosphoric acid diester, tetrathiophosphoric acid diester A phosphoric acid triester, monothiophosphoric acid triester, dithiophosphoric acid triester, trithiophosphoric acid triester, tetrathiophosphoric acid triester having three hydrocarbon groups having 1 to 30 carbon atoms; a hydrocarbon having 1 to 30 carbon atoms; E having 1 to 3 groups Phosphonic acid, phosphonic acid monoester, phosphonic acid diester; phosphorus compound having a (poly) oxyalkylene group having 1 to 4 carbon atoms; β-dithiophosphorylated propionic acid, dithiophosphoric acid and olefin cyclopentadiene or (methyl) methacrylic acid And derivatives of the above phosphorus compounds such as a reaction product thereof, and mixtures thereof. Furthermore, only metal bases such as metal oxides, metal hydroxides, metal carbonates, metal chlorides, ammonia, hydrocarbon groups having 1 to 30 carbon atoms or hydroxyl group-containing hydrocarbon groups in the above phosphorus compound are contained in the molecule. And a salt obtained by allowing a nitrogen compound such as an amine compound to act on a part of or all of the remaining acidic hydrogen.

  As other antiwear agents, known ones such as boric acid esters, ashless antiwear agents, and metal antiwear agents can be used.

  In the lubricating oil composition of the present invention, the content of the antiwear agent is usually 0.01 to 10% by mass, preferably 0.1 to 5% by mass, based on the total amount of the composition.

  Examples of the corrosion inhibitor include benzotriazole, tolyltriazole, thiadiazole, and imidazole compounds.

  Examples of the rust inhibitor include petroleum sulfonate, alkylbenzene sulfonate, dinonylnaphthalene sulfonate, alkenyl succinic acid ester, and polyhydric alcohol ester.

  Examples of the demulsifier include polyalkylene glycol nonionic surfactants such as polyoxyethylene alkyl ether, polyoxyethylene alkyl phenyl ether, and polyoxyethylene alkyl naphthyl ether.

  Examples of metal deactivators include imidazoline, pyrimidine derivatives, alkylthiadiazoles, mercaptobenzothiazoles, benzotriazoles or derivatives thereof, 1,3,4-thiadiazole polysulfide, 1,3,4-thiadiazolyl-2,5-bis. Examples include dialkyldithiocarbamate, 2- (alkyldithio) benzimidazole, and β- (o-carboxybenzylthio) propiononitrile.

  When the lubricating oil composition of the present invention contains a pour point depressant, since the effect of adding the pour point depressant by the lubricating base oil according to the present invention is maximized, excellent low temperature viscosity characteristics (−40 MRV viscosity at a temperature of preferably 20000 mPa · s or less, more preferably 15000 mPa · s or less, still more preferably 10,000 mPa · s or less). In addition, MRV viscosity at -40 degreeC here means MRV viscosity at -40 degreeC measured based on JPI-5S-42-93. In this case, the blending amount of the pour point depressant is 0.05 to 2% by mass, preferably 0.1 to 1.5% by mass, based on the total amount of the composition, but in particular the MRV viscosity can be lowered. The pour point depressant is preferably from 1 to 300,000, more preferably from 5 to 200,000, and more preferably fluid. As the point depressant, polymethacrylates are particularly preferable.

  As the antifoaming agent, any compound usually used as an antifoaming agent for lubricating oil can be used, and examples thereof include silicones such as dimethyl silicone and fluorosilicone. One or two or more compounds arbitrarily selected from these can be blended in any amount. Examples of antifoaming agents include silicone oil, alkenyl succinic acid derivatives, esters of polyhydroxy aliphatic alcohols and long chain fatty acids, methyl salicylate and o-hydroxybenzyl alcohol, aluminum stearate, potassium oleate, N-dialkyl-allylamine Nitroaminoalkanol, aromatic amine salt of isoamyl octyl phosphate, alkylalkylene diphosphate, metal derivative of thioether, metal derivative of disulfide, fluorine compound of aliphatic hydrocarbon, triethylsilane, dichlorosilane, alkylphenyl polyethylene glycol ether sulfide, fluoro Examples thereof include alkyl ethers.

  As the colorant, any compound that is usually used can be used, and any amount can be blended. Usually, the blending amount is 0.001 to 1.0% by mass based on the total amount of the composition. is there.

  When these additives are contained in the lubricating oil composition of the present invention, the content is based on the total amount of the composition, 0.005 to 5% by mass for the corrosion inhibitor, the rust inhibitor, and the demulsifier, respectively, and the metal inertness. 0.005 to 1% by mass for the agent, 0.01 to 1% by mass for the pour point depressant, 0.0001 to 1% by mass for the antifoaming agent, and 0.001 to 1.0% by mass for the colorant. Usually selected by range.

  The sulfur content in the lubricating oil composition of the present invention is not particularly limited, but is preferably 0.2% by mass or less, more preferably 0.1% by mass or less, and 0.01% by mass or less. More preferably, it is particularly preferably 0.001% by mass or less. When the sulfur content is more than 0.2% by mass, the life of the oxidation catalyst, NOx storage reduction catalyst, and DPF of the exhaust gas aftertreatment device tends to be short when used for an internal combustion engine. Further, the sulfated ash content of the lubricating oil composition of the present invention is preferably 1% by mass or less, more preferably 0.8% by mass or less, and still more preferably 0 from the viewpoint of maintaining the performance of the exhaust gas aftertreatment device. The composition having excellent high-temperature cleanability can be obtained by adjusting the content to 0.6 mass% or less, preferably 0.1 mass% or more, and particularly 0.3 mass% or more.

  The phosphorus content in the lubricating oil composition of the present invention is not particularly limited, but is preferably 0.1% by mass or less, more preferably 0.8% by mass or less, and 0.05% by mass or less. By substantially not including the phosphorus-containing additive, a lubricating oil composition having a phosphorus content of 0.01% by mass or less or no phosphorus can be obtained.

Kinematic viscosity at 100 ° C. of the lubricating oil composition of the present invention is preferably 21.9 mm ² / s or less, more preferably 16.3 mm ² / s or less, more preferably 12.5 mm ² / s or less, particularly preferably It is 9.3 mm ² / s or less. Further, the kinematic viscosity at 100 ° C. of the lubricating oil composition of the present invention is preferably 3.8 mm ² / s or more, more preferably 4.1 mm ² / s or more, further preferably 5.6 mm ² / s or more, particularly Preferably it is 8.0 mm < ² > / s or more. When the kinematic viscosity at 100 ° C. is less than 3.8 mm ² / s, there is a risk of insufficient lubricity, and when it exceeds 21.9 mm ² / s, the necessary low temperature viscosity and sufficient fuel saving performance are obtained. There is a risk of not being able to.

  The viscosity index of the lubricating oil composition of the present invention is preferably in the range of 140 to 300, more preferably 160 or more, still more preferably 180 or more, still more preferably 200 or more, and particularly preferably 220 or more. By setting the viscosity index of the lubricating oil composition of the present invention to 140 or more, it is possible to obtain a lubricating oil composition having an appropriate viscosity from low to high temperatures and excellent in low friction performance.

  Since the lubricating oil composition of the present invention can achieve sufficient wear resistance and oxidation stability using a metal-free, phosphorus-free, and sulfur-free additive, it can be applied to a wide range of applications. Can do. For example, it is a lubricating oil composition suitable for diesel engines and direct injection gasoline engines equipped with exhaust gas aftertreatment devices such as DPF and various catalysts. Moreover, it can be used not only for engines for such applications, but also for gasoline engines, diesel engines, gas engines for motorcycles, automobiles, power generation, cogeneration, etc. Not only can it be suitably used for these various engines using fuel of 50 mass ppm or less, but it is also useful for various engines for ships and outboard motors. Further, a low sulfur fuel, for example, a fuel having a sulfur content of 50 mass ppm or less, more preferably 30 mass ppm or less, particularly preferably 10 mass ppm or less (for example, gasoline, light oil, kerosene, alcohol, dimethyl ether, LPG, natural gas, (Hydrogen, GTL (Gas Liquid) fuel, etc.) are suitable for lubricating oil for internal combustion engines. The lubricating oil composition of the present invention is used as a lubricating oil for drive systems such as automatic or manual transmissions, grease, wet brake oil, hydraulic hydraulic oil, turbine oil, compressor oil, bearing oil, refrigerator oil, etc. Can also be suitably used.

  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 base oil 1]
First, 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 component (hereinafter referred to as “WAX1”), which was removed during solvent dewaxing and obtained as slack wax, was used as a base oil for a lubricating base oil. Table 1 shows the properties of WAX1.

  Next, hydroprocessing was performed using WAX1 as a raw material oil and a hydroprocessing catalyst. At this time, the reaction temperature and the liquid space velocity were adjusted so that the decomposition rate of a fraction of less than 370 ° C. in the feedstock was 5% by mass or more.

  Next, about the to-be-processed object obtained by said hydrogenation process, in the temperature range of 315 degreeC-325 degreeC using the zeolite-type hydrodewaxing catalyst adjusted to noble metal content 0.1 to 5 weight%. Hydrodewaxing was performed.

  Furthermore, the to-be-processed object (raffinate) obtained by the above hydrodewaxing was hydrorefined using a hydrogenation catalyst. Thereafter, a light component and a heavy component were separated by distillation to obtain a lubricating base oil (base oil 1) having the composition and properties shown in Table 3. In Table 3, “ratio of components derived from normal paraffin in urea adduct” is obtained by performing gas chromatography analysis on the urea adduct obtained at the time of measuring the urea adduct value. Yes (the same applies hereinafter).

[Manufacture of base oil 2]
First, an FT wax having a paraffin content of 95% by mass and having a carbon number distribution of 20 to 80 (hereinafter referred to as “WAX2”) was prepared. Table 2 shows the properties of WAX2.

  Next, a lubricating oil having the composition and properties shown in Table 3 was obtained by performing hydrotreatment, hydrodewaxing, hydrorefining and distillation in the same manner as base oil 1 except that WAX2 was used instead of WAX1. A base oil (Base oil 2) was obtained.

[Base oils 3 and 4]
As the base oil 3 and the base oil 4, mineral oil base oils having properties shown in Table 3 below were prepared. The base oil 3 was obtained by isomerization and dewaxing so that the bottom fraction (HDC bottom) obtained from the fuel oil hydrocracking apparatus had a saturated content of 95% by mass or more and a viscosity index of 100 or more. The base oil 4 is a lubricating base oil obtained by a solvent refining-solvent dewaxing process so that the saturated content is 95% by mass or more and the viscosity index is 100 or more.

[Examples 1-8, Comparative Examples 1-6]
In Examples 1 to 8 and Comparative Examples 1 to 6, lubricating oil compositions having the compositions shown in Tables 4 to 6 were prepared using the base oils 1 to 4 shown in Table 3 and the additives shown below. .
(Additive)
A1: Alkylated diphenylamine B1: Alkanoyl borate (a compound in which ^one of R ¹ and R ² is hydrogen and the other is an n-octyl group in general formula (1))
B2: Alkanoyl borate (in general formula (1), ^one of R ¹ and R ² is hydrogen and the other is an n-octadecyl group)
B3: Alkanoyl borate (a compound in which R ¹ and R ² are both n-octyl groups in the general formula (1))
B4: Alkanoyl borate (in general formula (1), ^one of R ¹ and R ² is an n-butyl group and the other is an n-octadecyl group)
B5: Alkanoyl borate (a compound in which R ¹ and R ² in the general formula (1) are both n-octadecyl groups)
C1: Ca sulfonate D1: Polybutenyl succinimide (bis type, weight average molecular weight: 8,500, nitrogen content: 0.65% by mass)
E1: Polymethacrylate viscosity index improver (number average molecular weight 295,000)

  Various properties of the lubricating oil compositions of Examples 1 to 8 and Comparative Examples 1 to 6 are shown in Tables 4 to 6. Here, the “acid number” and “base number” in Tables 4 to 6 are the properties of the new oil before the oxidation test. The “acid value increase” means an increase amount of the acid value before and after the implementation of the ISOT test (165.5 ° C., 24 hours). Furthermore, “amount of wear” means the total weight loss of the pins and blocks before and after operation for 30 minutes at 500 lbf, measured in a friction test using a Flaex P / V tester.

Claims (4)

A lubricant base oil having a saturated content of 90% by mass or more, a cyclic saturated content in the saturated content of 60% by mass or less, and a viscosity index of 100 or more;
A lubricating oil composition comprising an alkanoyl borate represented by the following general formula (1):

[In Formula (1), R ¹ and R ² may be the same or different, and each represents hydrogen or an alkyl group or alkenyl group having 1 to 30 carbon atoms. ]   The lubricating oil composition according to claim 1, wherein a urea adduct value of the lubricating base oil is 4% by mass or less.   Hydrocracking / hydroisomerization so that the lube base oil contains a normal paraffin, the urea adduct value of the material to be treated is 4% by mass or less and the viscosity index is 100 or more. The lubricating oil composition according to claim 1, wherein the lubricating oil composition is a lubricating base oil obtained by the step of converting into a lubricating oil.   The lubricating oil composition according to claim 3, wherein the raw material oil contains 50% by mass or more of slack wax obtained by solvent dewaxing of a lubricating base oil.