JP2008069321A - Heat-treatment oil - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a heat-treatment oil exhibiting high cooling performance in a treatment such as the hardening of a metallic material and having high flash point and lowered fire hazard risk. <P>SOLUTION: The heat-treatment oil contains a base oil containing ≥70 mass% α-olefin oligomer compound and satisfies formula (1): FP≥250 loglogν+200 wherein FP(°C) is flash point and ν (mm<SP>2</SP>/s) is kinematic viscosity of the oil at 40°C. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a heat-treated oil, and more specifically, includes a base oil mainly composed of an α-olefin oligomer compound, and has a good cooling property and a high flash point in a treatment such as quenching of a metal material. The present invention relates to a heat-treated oil with reduced risk.

In heat treatment of metals, especially quenching, it is important to select heat treatment oils suitable for the heat treatment conditions. If the selection is inappropriate, sufficient quenching hardness may not be obtained, and significant distortion may occur. May occur.
In the quenching of the steel material, for example, the heated steel material in an austenite state is cooled at an upper critical cooling rate or more to transform it into a quenched structure such as martensite. By this quenching, the processed material becomes very hard. In this case, an oil-based, aqueous (aqueous solution), or emulsion-based heat treatment liquid is generally used as the coolant. The quenching of the steel material will be described. When the heated steel material is put into a heat treatment liquid as a coolant, the cooling rate is not constant, and usually goes through three stages. That is, (1) the first stage (steam film stage) in which the steel material is encased in steam of the heat treatment liquid, (2) the second stage (boiling stage) in which the steam film is broken and boiling occurs, and (3) the temperature of the steel material is It becomes below the boiling point of heat processing liquid, and it cools through the 3rd stage (convection stage) from which heat is taken by convection. In these three stages, the cooling rate is the highest in the second boiling stage. In conventional heat-treated oils, the heat transfer coefficient, which indicates the cooling performance, rises abruptly, especially in the boiling stage, and a very large temperature difference occurs in the state where the vapor film stage and the boiling stage coexist on the surface of the processed material, and the heat shrinkage associated therewith. Thermal stress and transformation stress are generated due to the difference in temperature and transformation time, and the quenching strain increases.
As a heat-treated oil composition that overcomes the disadvantages of such conventional heat-treated oils and is hard to cause uneven cooling in quenching of a metal material, ensuring the hardness of the quenched product and reducing quenching distortion, ( a) temperature 40 50 to 95 weight percent low viscosity base oil having kinematic viscosity of 5 to 60 mm ² / s at ° C., (B) a kinematic viscosity at 40 ° C. is not less than 300 mm ² / s high-viscosity base oil 50-5 A heat-treated oil composition containing a mixed base oil consisting of% by weight and optionally (C) a vapor film breaker is disclosed (see, for example, Patent Document 1).

By the way, in general, carbon steel is a steel material that is difficult to so-called “quenching”, and therefore quenching of carbon steel contains synthetic polymer hydrocarbons and asphalt petroleum-based polymer hydrocarbons as hardenability improvers. A quenching oil having a kinematic viscosity at 40 ° C. of about 10 to 20 mm ² / s is used, and a heat treatment oil having a viscosity as low as possible as a quenching oil for a steel material that is difficult to quench due to its good quenchability. Is usually chosen. However, as a general tendency, the heat-treated oil having a low viscosity has a disadvantage that the flammability becomes high because a relatively large amount of low-boiling mineral oil is blended. Quenching is an operation in which a steel material heated to a high temperature is poured into the oil and rapidly cooled, so it can be said that the use of heat-treated oil with high flammability is always dangerous.
Under such circumstances, 5% distillation temperature is 290 to 310 ° C. as a heat-treated oil that can impart sufficient hardness to a steel material with poor quenching hardenability and has low flammability, and A heat-treated oil having a kinematic viscosity at 40 ° C. of 12 to 30 mm ² / s is disclosed (for example, see Patent Document 2).
In general, heat-treated oils are desired to have a high flash point in order to avoid the risk of ignition on the oil surface, and therefore a high viscosity base oil is employed. However, the cooling property of the heat-treated oil tends to be lower as the viscosity is higher. That is, when it is desired to increase the flash point, the cooling performance is sacrificed.
The heat-treated oil composition and the heat-treated oil disclosed in the above publication cannot be said to sufficiently satisfy both the high flash point and the good cooling properties.

JP 2002-327191 A Japanese Patent Laid-Open No. 10-158777

  An object of the present invention is to provide a heat-treated oil that has good cooling properties, a high flash point, and a reduced risk of fire in such conditions as quenching of a metal material. To do.

As a result of intensive studies to develop a heat-treated oil having the above-mentioned preferable properties, the present inventor includes α-olefin oligomeric compounds at a ratio of a certain value or more, and the flash point and kinematic viscosity have a specific relationship. It has been found that a heat-treated oil containing a certain base oil can meet its purpose. The present invention has been completed based on such findings.
That is, the present invention
[1] An α-olefin oligomer compound containing 70% by mass or more, and a flash point FP (° C.) and a 40 ° C. kinematic viscosity ν (mm ² / s) are represented by the formula (1)
FP ≧ 250loglogν + 200 (1)
A heat-treated oil characterized by containing a base oil satisfying the relationship
[2] The heat-treated oil according to the above [1], wherein the base oil has a kinematic viscosity at 40 ° C. of 4 to 100 mm ² / s,
[3] The heat-treated oil according to the above [1] or [2] containing a vapor film breaker,
[4] The above [1] to [1], wherein the α-olefin oligomer compound is at least one selected from compounds having 8 to 72 carbon atoms and having structures represented by formulas (2) to (8): 3], the heat-treated oil according to any one of

［式中、ｐ、ｑ及びｒは、それぞれ独立に０〜１８の整数、ｎは０〜８の整数を示し、ｎが２以上の場合、ｑは繰り返し単位毎同一でも異なっていてもよく、ｐ＋ｎ×（２＋ｑ）＋ｒの値は４〜５２である。
ａ、ｂ及びｃは、それぞれ独立に０〜１８の整数、ｍは０〜８の整数を示し、ｍが２以上の場合、ｂは繰り返し単位毎同一でも異なっていてもよく、ａ＋ｍ×（２＋ｂ）＋ｃの値は４〜５２である。
Ｒ¹〜Ｒ¹²は、それぞれ独立に水素原子又は炭素数１〜１６の直鎖状若しくは分岐を有するアルキル基を示し、Ｒ¹〜Ｒ⁴の合計炭素数、Ｒ⁵〜Ｒ⁸の合計炭素数及びＲ⁹〜Ｒ¹²の合計炭素数は、それぞれが０〜６４の整数である。
Ｒ¹³及びＲ¹⁶は炭素数２〜２２の直鎖状若しくは分岐を有するアルキル基、Ｒ¹⁴及びＲ¹⁵は、それぞれ独立に水素原子又は炭素数１〜２２の直鎖状若しくは分岐を有するアルキル基を示し、Ｒ¹³〜Ｒ¹⁵の合計炭素数及びＲ¹⁶〜Ｒ¹⁸の合計炭素数は、それぞれ２〜６６の整数である。］

[Wherein, p, q and r each independently represent an integer of 0 to 18, n represents an integer of 0 to 8, and when n is 2 or more, q may be the same or different for each repeating unit, The value of p + n × (2 + q) + r is 4 to 52.
a, b and c are each independently an integer of 0 to 18, m is an integer of 0 to 8, and when m is 2 or more, b may be the same or different for each repeating unit, and a + m × (2 + b ) The value of + c is 4 to 52.
R ^{1 to} R ¹² each independently represent a hydrogen atom or a linear or branched alkyl group having ¹ to 16 carbon atoms, the total carbon number of R ^{1 to} R ^{4 and} the total carbon number of R ^{5 to} R ^8. And the total carbon number of R ^{9 to} R ¹² is an integer of 0 to 64, respectively.
R ¹³ and R ¹⁶ are each a linear or branched alkyl group having 2 to 22 carbon atoms, and R ¹⁴ and R ¹⁵ are each independently a hydrogen atom or a linear or branched alkyl group having 1 to 22 carbon atoms. are shown, the total number of carbon atoms of R ¹³ to R ¹⁵ and the total number of carbon atoms of R ¹⁶ to R ¹⁸ are each an integer of 2-66. ]

[5] An α-olefin having 8 to 72 carbon atoms obtained by oligomerizing an α-olefin having 2 to 20 carbon atoms using a metallocene catalyst, the α-olefin oligomer compound represented by the formula (2) The heat-treated oil according to the above [4], which is an oligomer,
[6] The α-olefin oligomer compound represented by the formula (3) is an α-olefin having 8 to 72 carbon atoms obtained by oligomerizing the α-olefin having 2 to 20 carbon atoms using a metallocene catalyst. The heat-treated oil according to the above [4], which is a hydrogenated product of an oligomer,
[7] The vinylidene olefin obtained by dimerizing the α-olefin using the metallocene catalyst as the α-olefin oligomer compound represented by the formula (4) and the formula (5) is further obtained using an acid catalyst. The heat-treated oil according to the above [4], which is a dimerized α-olefin tetramer,
[8] An α-olefin oligomer compound represented by the formula (6) is obtained by further dimerizing a vinylidene olefin obtained by dimerizing an α-olefin using a metallocene catalyst using an acid catalyst. The heat-treated oil according to the above [4], which is a hydrogenated product of α-olefin tetramer,
[9] The α-olefin oligomer compound represented by the formula (7) is a vinylidene olefin obtained by dimerizing an α-olefin using a metallocene catalyst, and an acid catalyst is used to obtain 4 to 24 carbon atoms. The heat-treated oil according to the above [4], which is a compound formed by adding an α-olefin of the above, and [10] an α-olefin oligomeric compound represented by the formula (8) using a metallocene catalyst, The heat-treated oil according to the above [4], which is a compound obtained by adding an α-olefin having 4 to 24 carbon atoms to a vinylidene olefin obtained by dimerization of an α-olefin using an acid catalyst and hydrogenating the vinylidene olefin,
Is to provide.

  According to the present invention, it contains a base oil mainly composed of an α-olefin oligomer compound, and has a good cooling property, a high flash point, and a reduced risk of fire in a treatment such as quenching of a metal material. Heat treated oil can be provided.

In the heat-treated oil of the present invention, an oil containing 70% by mass or more, preferably 80% by mass or more, more preferably 90% by mass or more, and particularly preferably 100% by mass is used as the base oil. . When the content of the α-olefin oligomer compound in the base oil is less than 70% by mass, it is difficult to obtain a base oil satisfying the relationship of the following formula (1).
The base oil has a flash point FP (° C.) and a 40 ° C. kinematic viscosity ν (mm ² / s) according to the formula (1)
FP ≧ 250loglogν + 200 (1)
It is necessary to satisfy this relationship. When the flash point is lower than the value of “250 log log ν + 200” (ν is the same as described above), the base oil has a large amount of evaporation at the required kinematic viscosity (viscosity with good cooling properties), and the flash point is low. Thus, a fire may occur during the quenching of the metal material, and the object of the present invention cannot be achieved.
The base oil is preferably a formula (1-a)
FP ≧ 250loglogν + 205 (1-a)
More preferably, the formula (1-b)
FP ≧ 250loglogν + 210 (1-b)
(FP and ν are the same as above.)
It is desirable to satisfy this relationship.

In the base oil, the kinematic viscosity at 40 ° C., preferably in the range of 4~100mm ² / s, and more preferably in the range of 4~50mm ² / s. If the kinematic viscosity at 40 ° C. of the base oil is in the range of 4 to 100 mm ² / s, it has good hardenability (coolability, prevention of distortion and cracking), and flash point of 160 to 260 ° C. The risk of ignition is small.
The kinematic viscosity is a value measured according to JIS K 2283, and the flash point is a value measured by the COC method according to JIS K 2265.
Moreover, as an alpha olefin oligomer type compound used for the said base oil, Formula (2)-Formula (8)

The at least 1 sort (s) chosen from the C8-72 compound which has a structure represented by these can be mentioned. If the α-olefin oligomeric compound has a carbon number in the range of 8 to 72, a base oil having low-temperature fluidity, high flash point, low evaporation and good oxidation stability can be obtained. The heat-treated oil thus obtained can achieve the object of the present invention. The preferred carbon number is in the range of 8-40.
First, the α-olefin oligomer compound represented by the formula (2) will be described.
The α-olefin oligomeric compound represented by the formula (2) has a structure having a vinylidene bond at the terminal. In the formula (2), p, q and r are each independently 0 to 18 An integer, n represents an integer of 0 to 8, and when n is 2 or more, q may be the same or different for each repeating unit, and the value of p + n × (2 + q) + r is 4 to 52.
Such an α-olefin oligomer compound is not particularly limited in its production method, and has the above-described structure, and the relationship between the flash point FP and the 40 ° C. kinematic viscosity ν satisfies the above formula (1). As long as the compound is obtained, any method may be used, but in particular, an α-olefin having 8 to 72 carbon atoms obtained by oligomerization of an α-olefin having 2 to 20 carbon atoms using a metallocene catalyst. Oligomers are preferred.

Examples of the α-olefin having 2 to 20 carbon atoms of the raw material include ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene and 1-undecene. 1-dodecene, 1-tridecene, 1-tetradecene, 1-pentadecene, 1-hexadecene, 1-heptadecene, 1-octadecene, 1-nonadecene, 1-icosene. These α-olefins may be linear or branched. In the present invention, one type may be used alone, or two or more types may be used in combination.
In the present invention, as the metallocene catalyst used for oligomerization of α-olefin, a conventionally known catalyst, for example, (a) a metallocene complex containing a group 4 element of the periodic table, and (b) (b-1) (A) A combination of a compound capable of forming an ionic complex by reacting with the component metallocene complex or a derivative thereof and / or (b-2) an aluminoxane and (c) an organoaluminum compound used as desired. be able to.

As the metallocene complex containing the Group 4 element of the Periodic Table of the component (a), a complex having a conjugated carbon 5-membered ring containing titanium, zirconium or hafnium, preferably zirconium can be used. Here, as a complex having a conjugated carbon 5-membered ring, a complex having a substituted or unsubstituted cyclopentadienyl ligand can be generally mentioned.
Examples of the metallocene complex of the catalyst component (a) include conventionally known compounds such as bis (n-octadecylcyclopentadienyl) zirconium dichloride, bis (trimethylsilylcyclopentadienyl) zirconium dichloride, bis (tetrahydroindenyl) zirconium dichloride. Bis [(t-butyldimethylsilyl) cyclopentadienyl] zirconium dichloride, bis (di-t-butylcyclopentadienyl) zirconium dichloride, ethylidenebis (indenyl) zirconium dichloride, biscyclopentadienyl zirconium dichloride, ethylidene Bis (tetrahydroindenyl) zirconium dichloride and bis [3,3- (2-methyl-benzindenyl)] dimethylsilanediylzirconium dichloride, ( , 2'-dimethylsilylene) (2,1'-dimethylsilylene) bis (3-trimethylsilyl-methylindenyl) such as zirconium dichloride.
These metallocene complexes may be used individually by 1 type, and may be used in combination of 2 or more type.

Examples of the compound (b-1) that can react with the metallocene complex or a derivative thereof to form an ionic complex include dimethylanilinium tetrakispentafluorophenylborate and triphenylcarbenium tetrakispentafluorophenyl. Examples thereof include borates such as borates. These may be used individually by 1 type and may be used in combination of 2 or more type.
Examples of the aluminoxane as the (b-2) compound include chain aluminoxanes such as methylaluminoxane, ethylaluminoxane, butylaluminoxane, and isobutylaluminoxane, and cyclic aluminoxanes. These aluminoxanes may be used alone or in combination of two or more.
In the present invention, as the catalyst component (b), one or more compounds (b-1) may be used, one or more compounds (b-2) may be used, and (b-1) One or more compounds and (b-2) one or more compounds may be used in combination.

The use ratio of (a) catalyst component to (b) catalyst component is preferably 10: 1 to 1: 100 in terms of molar ratio when (b-1) compound is used as (b) catalyst component. Preferably, the range of 2: 1 to 1:10 is desirable, and if it deviates from the above range, the catalyst cost per unit mass polymer increases, which is not practical. When the (b-2) compound is used, the molar ratio is preferably 1: 1 to 1: 1000000, more preferably 1:10 to 1: 10000. When deviating from this range, the catalyst cost per unit mass polymer becomes high, which is not practical.
Examples of the (c) organoaluminum compound used as a catalyst component include trimethylaluminum, triethylaluminum, triisopropylaluminum, triisobutylaluminum, dimethylaluminum chloride, diethylaluminum chloride, methylaluminum dichloride, ethylaluminum dichloride, dimethyl. Examples include aluminum fluoride, diisobutylaluminum hydride, diethylaluminum hydride, ethylaluminum sesquichloride, and the like.
These organoaluminum compounds may be used individually by 1 type, and may be used in combination of 2 or more type.

The use ratio of the catalyst component (a) to the catalyst component (c) is preferably 1: 1 to 1: 10000, more preferably 1: 5 to 1: 2000, still more preferably 1:10 to 1 in terms of molar ratio. : The range of 1000 is desirable. By using the catalyst component (c), the polymerization activity per transition metal can be improved. However, if it is too much, the organoaluminum compound is wasted and a large amount remains in the polymer, which is not preferable.
When a catalyst is prepared using the catalyst component (a) and the catalyst component (b), the contact operation is preferably performed in an inert gas atmosphere such as nitrogen gas.
Moreover, when preparing a catalyst using (a) catalyst component, (b) catalyst component, and (c) organoaluminum compound, (b) catalyst component and (c) organoaluminum compound may be contacted in advance. A sufficiently high active catalyst can also be obtained by contacting the component (a), the component (b) and the component (c) in the presence of an α-olefin.
As the catalyst component, one prepared in advance in a catalyst preparation tank may be used, or one prepared in an oligomerization step may be used for the reaction.
The oligomerization of the α-olefin may be either a batch type or a continuous type. In the oligomerization, a solvent is not necessarily required, and the oligomerization can be carried out in a suspension, a liquid monomer or an inert solvent. In the case of oligomerization in a solvent, liquid organic hydrocarbons such as benzene, ethylbenzene, toluene and the like are used. The oligomerization is preferably carried out in a reaction mixture in which liquid monomer is present in excess.

The conditions for oligomerization are a temperature of about 15 to 100 ° C. and a pressure of about atmospheric pressure to about 0.2 MPa. Moreover, the use ratio of the catalyst with respect to the α-olefin is such that the molar ratio of the α-olefin / (A) component metallocene complex is usually 1000 to 10 ⁶ , preferably 2000 to 10 ⁵ , and the reaction time is usually 10 minutes to It is about 48 hours.
As a post-treatment of the oligomer reaction, first, a known deactivation treatment is performed by adding water or alcohol to the reaction system, and after the oligomerization reaction is stopped, the catalyst is deashed using an alkaline aqueous solution or an alcohol-alkaline solution. Do. Next, neutralization washing, distillation operation, and the like are performed to remove unreacted α-olefin and olefin isomers by-produced in the oligomerization reaction by stripping, and further represented by the formula (2) having a desired degree of polymerization. The α-olefin oligomer is isolated.
Thus, although the alpha olefin oligomer manufactured by the metallocene catalyst has a double bond, the content of the terminal vinylidene bond is particularly high.

Next, the α-olefin oligomer compound represented by the formula (3) will be described.
The α-olefin oligomeric compound represented by the formula (3) has a saturated structure having no unsaturated bond in the molecule. In the formula (3), a, b, c and m are The same as p, q, r and n in the formula (2).
Such an α-olefin oligomer compound is not particularly limited in its production method, and has the above-described structure, and the relationship between the flash point FP and the 40 ° C. kinematic viscosity ν satisfies the above formula (1). As long as such a compound can be obtained, any method may be used, but the following method is preferably employed. That is, an α-olefin oligomer having a desired degree of polymerization isolated as described above is obtained by oligomerizing an α-olefin by a method similar to the compound of the formula (2) using a metallocene catalyst. The method of producing by hydrogenation by a known method, or after the above-mentioned oligomerization reaction, after decalcification treatment, neutralization treatment and washing treatment, the isolation operation of α-olefin oligomer by distillation is not performed. The hydrogenated product of the α-olefin oligomer having a desired degree of polymerization is then isolated by distillation, and then the product can be obtained by a method of production.

The hydrogenation reaction of α-olefin oligomer is carried out by using known hydrogenation catalysts such as Ni and Co catalysts, noble metal catalysts such as Pd and Pt, specifically diatomaceous earth-supported Ni catalysts, cobalt trisacetylacetonate / organoaluminum. The reaction is performed using a catalyst such as a catalyst, a palladium catalyst supported on activated carbon, or a platinum catalyst supported on alumina.
The conditions for the hydrogenation reaction are typically 150 to 200 ° C. for Ni-based catalysts and 50 to 150 ° C. for homogeneous noble metal catalysts such as Pd and Pt, and homogeneous systems such as cobalt trisacetylacetonate / organoaluminum. If it is a catalyst, it will normally be set as the temperature range of 20-100 degreeC, and a hydrogen pressure is a normal pressure-about 20 Mpa.
If the reaction temperature in each catalyst is in the above range, it is possible to suppress the formation of isomers in oligomers having an appropriate reaction rate and having the same degree of polymerization.

Next, the α-olefin oligomer compound represented by the formulas (4) and (5) will be described.
The α-olefin oligomer compound represented by the formula (4) and the formula (5) has a double bond in the molecule. In the formula (4) and the formula (5), R ^{1 to} R ⁸ Are each independently a hydrogen atom or a linear or branched alkyl group having 1 to 16 carbon atoms. In the present invention, it is preferably a linear alkyl group having 8 to 16 carbon atoms. Examples of the linear alkyl group having 8 to 16 carbon atoms include n-octyl group, n-nonyl group, n-decyl group, n-undecyl group, n-dodecyl group, n-tridecyl group, n-tetradecyl group, Examples include an n-pentadecyl group and an n-hexadecyl group. The total carbon number of R ^{1 to} R ^{4 and} the total carbon number of R ^{5 to} R ⁸ are each an integer of 0 to 64.
Such an α-olefin oligomer compound is not particularly limited in its production method, and has the above-described structure, and the relationship between the flash point FP and the 40 ° C. kinematic viscosity ν satisfies the above formula (1). As long as the compound is obtained, any method may be used. In particular, vinylidene olefin obtained by dimerizing α-olefin using a metallocene catalyst is further dimerized using acid catalyst, and α -It is preferable to use an olefin tetramer.
As the raw material α-olefin, the general formula H ₂ C═CH— (CH ₂ ) _n —CH ₃
(In the formula, n represents an integer of 7 to 15.)
Are preferable, and examples thereof include 1-decene, 1-dodecene, 1-tridecene, 1-tetradecene, 1-pentadecene, 1-hexadecene, 1-heptadecene and 1-octadecene. Among these, 1-decene, 1-dodecene and 1-tetradecene, in which n is an α-olefin of 7, 9 and 11, are preferably used. These α-olefins may be used alone or in combination of two or more.
The metallocene catalyst used for the dimerization of the α-olefin, the dimerization reaction conditions, the post-treatment, and the like are as described in the α-olefin oligomer represented by the above formula (2).

In the present invention, the vinylidene olefin obtained using the metallocene catalyst is further dimerized using an acid catalyst. In this case, the same vinylidene olefins may be reacted with each other or different vinylidene olefins may be reacted with each other.
As the acid catalyst in the dimerization reaction, a Lewis acid catalyst, a solid acid catalyst, or the like can be used, but a solid acid catalyst is preferable from the viewpoint of easy post-treatment operation.
Examples of the solid acid catalyst include acidic zeolite, acidic zeolite molecular sieve, acid-treated clay mineral, acid-treated porous desiccant or ion exchange resin. That is, the solid acid catalyst is an acidic zeolite such as HY, acidic zeolite molecular sieve having a pore size of about 0.5 to 2 nm, silica alumina, silica magnesia, montmorillonite or halloysite treated with an acid such as sulfuric acid, Ion exchange resin systems including porous desiccants such as silica gel and alumina gel with hydrochloric acid, sulfuric acid, phosphoric acid, organic acid, BF _3, etc., or sulfonated products of divinylbenzene / styrene copolymer Solid acid catalyst.

The addition amount of a solid acid catalyst is 0.05-20 mass parts normally with respect to 100 mass parts of preparation amounts of vinylidene olefin. When the addition amount of the solid acid catalyst is more than 20 parts by mass, not only is it uneconomical, but a side reaction proceeds and the viscosity of the reaction solution may increase or the yield may decrease. When the amount is less than 0.05 parts by mass, the reaction efficiency becomes low and the reaction time becomes long.
More preferable addition amount is affected by the acidity of the solid acid catalyst. For example, in the case of sulfuric acid treatment of a montmorillonite clay mineral, 3 to 15 parts by mass with respect to 100 parts by mass of the vinylidene olefin charged. In the case of a sulfonated ion exchange resin of divinylbenzene / styrene copolymer, 1 to 5 parts by mass is preferable. Depending on the reaction conditions, two or more of these solid acid catalysts may be used in combination.
The reaction is usually performed at a temperature of 50 to 150 ° C., but it is preferable to perform the reaction at 70 to 120 ° C. because the activity and selectivity can be improved. The reaction pressure is from atmospheric pressure to about 1 MPa, but the effect of pressure on the reaction is small.
Thus, the α-olefin tetramer represented by the above formula (4) or formula (5) is obtained.
This vinylidene olefin dimerization reaction liquid contains unreacted vinylidene olefin, vinylidene olefin trimer and the like in addition to the above-mentioned vinylidene olefin dimer (α-olefin tetramer). Therefore, after removing the solid acid catalyst from the dimerization reaction solution by filtration, the vinylidene olefin dimer (α-olefin tetramer represented by the above formula (4) or formula (5) is subjected to distillation treatment as necessary. (Mer) may be isolated.

Next, the α-olefin oligomer compound represented by the formula (6) will be described.
The α-olefin oligomer compound represented by the formula (6) has a saturated structure having no unsaturated bond in the molecule, and in the formula (6), R ^{9 to} R ¹² are the same as the above. R ^{1 to} R ⁴ in the formula (4) or R ^{5 to} R ⁸ in the formula (5) are the same.
Such an α-olefin oligomer compound is not particularly limited in its production method, and has the above-described structure, and the relationship between the flash point FP and the 40 ° C. kinematic viscosity ν satisfies the above formula (1). As long as such a compound can be obtained, any method may be used, but the following method is preferably employed. That is, first, in the same manner as the compounds of formula (4) and formula (5), vinylidene olefin obtained by dimerizing α-olefin using a metallocene catalyst and further dimerizing using an acid catalyst. A vinylidene olefin dimer (α-olefin tetramer) is produced.
Subsequently, it can obtain by hydrogenating the reaction liquid containing the vinylidene olefin dimer after a solid acid catalyst removal, or the vinylidene olefin dimer isolated by the distillation process of this reaction liquid. When the reaction solution is hydrogenated, the hydrogenated vinylidene olefin dimer may be isolated by distillation if necessary.
About the catalyst of this hydrogenation reaction, reaction conditions, etc., it is as having demonstrated in the hydrogenated substance of the alpha-olefin oligomer of said Formula (3).
In this way, a hydrogenated α-olefin oligomer represented by the formula (6) can be obtained.

Next, the α-olefin oligomer compound represented by the formula (7) will be described.
The α-olefin oligomer compound represented by the formula (7) has a double bond in the molecule, and R ^{13 in} the formula is a linear or branched alkyl group having 2 to 22 carbon atoms. , R ¹⁴ and R ¹⁵ each independently represent a hydrogen atom or a linear or branched alkyl group having 1 to 22 carbon atoms, and the total carbon number of R ^{13 to} R ¹⁵ is an integer of 2 to 66.
Such an α-olefin oligomer compound is not particularly limited in its production method, and has the above-described structure, and the relationship between the flash point FP and the 40 ° C. kinematic viscosity ν satisfies the above formula (1). As long as such a compound can be obtained, any method may be used, but the following method is preferably employed. That is, first, in the same manner as in the compounds of the above formulas (4) and (5), a vinylocene olefin obtained by dimerizing an α-olefin using a metallocene catalyst is added to a vinylidene olefin in the presence of an acid catalyst. A compound represented by the formula (7) can be obtained by adding 4 to 24 α-olefin.

The method of dimerizing the α-olefin using the metallocene catalyst is the same as the vinylidene olefin production step in the production of the α-olefin oligomer represented by the above formula (4) or formula (5). Similarly, by dimerizing the α-olefin, a vinylidene olefin can be selectively obtained in a high yield.
The vinylidene olefin thus obtained is added with an α-olefin having 4 to 24 carbon atoms using an acid catalyst.
The acid catalyst used in this addition reaction, the amount used, and the reaction conditions are the same as those in the dimerization step of vinylidene olefin described in the method for producing the compound represented by the above formula (4) or formula (5). It is. The α-olefin having 4 to 24 carbon atoms may be linear or branched. In the present invention, one type may be used alone, or two or more types may be used in combination.

Next, the α-olefin oligomer compound represented by the formula (8) will be described.
The α-olefin oligomeric compound represented by the formula (8) has a saturated structure having no unsaturated bond in the molecule, and R ¹⁶ , R ¹⁷ and R ¹⁸ in the formula are each represented by the formula: The same as R ¹³ , R ¹⁴ and R ¹⁵ in (7).
Such an α-olefin oligomer compound is not particularly limited in its production method, and has the above-described structure, and the relationship between the flash point FP and the 40 ° C. kinematic viscosity ν satisfies the above formula (1). As long as such a compound can be obtained, any method may be used, but the following method is preferably employed. That is, first, a vinylidene olefin obtained by dimerizing an α-olefin using a metallocene catalyst in the same manner as the compound of the above formula (7) is converted into an α-carbon having 4 to 24 carbon atoms using an acid catalyst. The compound of formula (8) can be obtained by adding an olefin and further hydrogenation.
About the method of hydrogenation reaction, a catalyst, reaction conditions, etc., it is as having demonstrated the hydrogenated substance of the alpha olefin oligomer of said Formula (3).

In the heat-treated oil of the present invention, as the base oil, the α-olefin oligomeric compounds represented by the above formulas (2) to (8) may be used alone or in appropriate combination of two or more. It may be used. In addition, when an α-olefin oligomer compound having a double bond is compared with a saturated α-olefin oligomer compound, a saturated α-olefin oligomer compound is preferable from the viewpoint of thermal stability and oxidation stability.
In the base oil, as long as the relationship between the flash point FP and the 40 ° C. kinematic viscosity ν satisfies the formula (1), mineral oil or synthetic oil other than the α-olefin oligomer compound described above is 30% by mass or less, Preferably it is 20 mass% or less, More preferably, it can contain in the ratio of 10 mass% or less.
As the mineral oil, a crude oil fraction obtained by atmospheric distillation and vacuum distillation is subjected to solvent degreasing, solvent extraction, hydrocracking, solvent dewaxing, catalytic dewaxing, hydrorefining, sulfuric acid washing, Examples thereof include paraffinic mineral oil and naphthenic mineral oil obtained by appropriately combining and applying refining treatment such as clay treatment. Synthetic oils include, for example, alkylbenzenes, alkylnaphthalenes, esters, polyoxyalkylene glycols, polyphenyl ethers, dialkyldiphenyl ethers, phosphate esters (such as tricresyl phosphate), fluorine-containing compounds (perfluoropolyethers, fluorinated polyolefins). Etc.), and silicone oil.

The heat-treated oil of the present invention can contain a vapor film breaker. By including this vapor film breaker, the vapor film stage is short and the increase in cooling performance in the boiling stage is suppressed, so that quenching distortion due to uneven cooling can be reduced. Moreover, the temperature range of a boiling stage is wide and the hardness of a processed material can be ensured.
Examples of the vapor film breaker include, for example, polymer polymers, specifically, ethylene-α-olefin copolymers, polyolefins, polymethacrylates, high molecular weight organic compounds such as asphaltam, oil-dispersed inorganic substances, and the like. Can be mentioned. These vapor film breakers may be used alone or in combination of two or more.
The content of the vapor film breaker is usually selected in the range of 1 to 10% by mass, preferably 3 to 6% by mass, based on the total amount of heat-treated oil. When the content is 1% by mass or more, the effect of the vapor film breaker is exhibited. On the other hand, when the content is 10% by mass or less, the viscosity of the heat-treated oil is increased and the performance is prevented from being lowered. Can do.

In the heat-treated oil of the present invention, various known additives that have been used in conventional heat-treated oils can be appropriately contained as desired according to the purpose of use within a range that does not impair the object of the present invention.
Examples of various additives include a glitter improvement agent, an antioxidant, and a cleaning dispersant.
Examples of the glitter improvement agent include conventionally known compounds, for example, fatty acids such as oleic acid and cottonseed oil fatty acid, fatty acid esters such as fats and oils, terpene resins, alkenyl succinimides, and substituted hydroxy aromatic carboxylic acid ester derivatives. . These glitter improvement agents may be used individually by 1 type, and may be used in combination of 2 or more type.
Conventionally known phenolic antioxidants and amine antioxidants can be used as the antioxidant.

  Examples of phenolic antioxidants include 2,6-di-tert-butyl-4-methylphenol; 2,6-di-tert-butyl-4-ethylphenol; 2,4,6-tri-tert-butylphenol. 2,6-di-tert-butyl-4-hydroxymethylphenol; 2,6-di-tert-butylphenol; 2,4-dimethyl-6-tert-butylphenol; 2,6-di-tert-butyl-4 -(N, N-dimethylaminomethyl) phenol; 2,6-di-tert-amyl-4-methylphenol; n-octadecyl 3- (4-hydroxy-3,5-di-tert-butylphenyl) propionate A monocyclic phenol, 4,4′-methylenebis (2,6-di-tert-butylphenol); Pyridenebis (2,6-di-tert-butylphenol); 2,2′-methylenebis (4-methyl-6-tert-butylphenol); 4,4′-bis (2,6-di-tert-butylphenol); 4 4,4′-bis (2-methyl-6-tert-butylphenol); 2,2′-methylenebis (4-ethyl-6-tert-butylphenol); 4,4′-butylidenebis (3-methyl-6-tert- Butylphenol); 2,2′-thiobis (4-methyl-6-tert-butylphenol); polycyclic phenols such as 4,4′-thiobis (3-methyl-6-tert-butylphenol).

Examples of amine-based antioxidants include diphenylamine-based compounds, specifically diphenylamine and monooctyldiphenylamine; monononyldiphenylamine; 4,4′-dibutyldiphenylamine; 4,4′-dihexyldiphenylamine; 4,4′-dioctyl. Diphenylamine; 4,4′-dinonyldiphenylamine; tetrabutyldiphenylamine; tetrahexyldiphenylamine; tetraoctyldiphenylamine: alkylated diphenylamine having 3 to 20 carbon atoms such as tetranonyldiphenylamine, and the like, and naphthylamine type Specifically, α-naphthylamine; phenyl-α-naphthylamine, further butylphenyl-α-naphthylamine; hexylphenyl-α-naphthylamine; octylphenyl α- naphthylamine; and alkyl-substituted phenyl -α- naphthylamine having 3 to 20 carbon atoms such as nonylphenyl -α- naphthylamine. Among these, the diphenylamine type is preferable to the naphthylamine type from the viewpoint of the effect, and in particular, an alkylated diphenylamine having an alkyl group having 3 to 20 carbon atoms, especially 4,4′-di (C _{3 to} C ₂₀ alkyl). Diphenylamine is preferred.
In this invention, 1 type (s) or 2 or more types chosen from the said phenolic antioxidant and amine antioxidant can be used as antioxidant.

As the cleaning dispersant, an ashless cleaning dispersant and / or a metal-based cleaning dispersant can be used.
Examples of the ashless detergent dispersant include alkenyl succinimides, boron-containing alkenyl succinimides, benzylamines, boron-containing benzylamines, succinic esters, fatty acids, and succinic acid. Examples of metal detergents include neutral metal sulfonates, neutral metal phenates, neutral metal salicylates, neutral metal phosphonates, basic sulfonates, basic phenates, and bases. Salicylates, overbased sulfonates, overbased salicylates, overbased phosphonates, and the like. These detergent dispersants may be used alone or in combination of two or more.
The detergent / dispersant has an effect of dispersing sludge produced by repeated use of heat-treated oil, but the metal detergent also has an action as a deteriorated acid neutralizer. Alkenyl succinimides also have an effect as a glitter improvement agent.

  The heat-treated oil of the present invention includes a base oil mainly composed of an α-olefin oligomer compound, and has a good cooling property, a high flash point, and a reduced risk of fire in heat treatment of metal materials. For example, carbon steel, nickel-manganese steel, chromium-molybdenum steel, manganese steel and other alloy steels when heat-treated such as quenching, annealing, tempering, etc., preferably when quenching It can be used as heat-treated oil.

EXAMPLES Next, although an Example demonstrates this invention further in detail, this invention is not limited at all by these examples.
The properties of the base oil and the cooling performance of the heat-treated oil were determined according to the following method.
<Properties of base oil>
(1) 40 ° C. kinematic viscosity [ν]
It was measured according to “Petroleum product kinematic viscosity test method” defined in JIS K 2283.
(2) Flash point Measured by the COC method in accordance with JIS K 2265.
<Coolability of heat-treated oil>
(3) JIS 400 ° C. Seconds Based on JIS K 2242, the number of seconds from 800 ° C. to 400 ° C. was determined from the silver bar cooling curve. The shorter it is, the higher the cooling performance.
(4) H value (hardening intensity)
A cooling curve was created in accordance with JIS K 2242, and the H value (cm ⁻¹ ) was determined. The larger the value, the higher the cooling performance.

Production Example 1
According to the following method, a hydrogenated product (mPAO-1) of an α-olefin oligomer using a metallocene catalyst was produced.
(A) Dimerization of decene In a three-necked flask with an internal volume of 5 liters substituted with nitrogen, 3.0 kg of 1-decene, 0.9 g of bis (cyclopentadienyl) zirconium dichloride which is a metallocene complex (also called zirconocene dichloride) (3 mmol) and methylaluminoxane (manufactured by Albemarle, 8 mmol in terms of Al) were sequentially added, and the mixture was stirred at room temperature (20 ° C. or lower). The reaction solution changed from yellow to reddish brown. After 48 hours from the start of the reaction, methanol was added to stop the reaction, and then an aqueous hydrochloric acid solution was added to the reaction solution to wash the organic layer. Next, the organic layer was vacuum distilled to obtain 2.5 kg of a fraction (decene dimer) having a boiling point of 120 to 125 ° C./26.6 Pa (0.2 Torr). When this fraction was analyzed by gas chromatography, the concentration of decene dimer was 99% by mass, and the vinylidene olefin ratio in the decene dimer was 97% by mass.
The flash point [FP] of this mPAO-1 was 178 ° C., and the kinematic viscosity [ν] at 40 ° C. was 4.975 mm ² / s.

Production Example 2
An α-olefin oligomer hydrogenated product (mPAO-2) using a metallocene catalyst was produced according to the following method.
(A) Oligomerization of decene A three-necked flask with an internal volume of 5 liters was charged with 4 liters (21.4 mol) of decene monomer (Idemitsu Kosan Co., Ltd .: Linearlen 10) under an inert gas stream. Methylalumoxane (Al conversion: 40 mmol) dissolved in toluene was added in the same manner as biscyclopentadienylzirconium dichloride (complex mass 1168 mg: 4 mmol) dissolved in toluene. These mixtures were kept at 40 ° C. and stirred for 20 hours, and then 20 ml of methanol was added to stop the oligomerization reaction. Next, the reaction mixture was taken out of the autoclave, 4 liters of a 5 mol / liter sodium hydroxide aqueous solution was added thereto, the mixture was forcedly stirred at room temperature for 4 hours, and then a liquid separation operation was performed. The upper organic layer was removed, and unreacted decene and side reaction product decene isomers were removed by stripping.
(B) Hydrogenation of decene oligomer Cobalt trisacetylacetonate (catalyst weight: 3.0 g) in which 3 liters of decene oligomer produced in (a) was placed in an autoclave with an internal volume of 5 liters under nitrogen flow and dissolved in toluene And triisobutylaluminum diluted with toluene (30 mmol) were added. After the addition, the inside of the system was replaced with hydrogen twice, and then the temperature was raised. The hydrogen pressure was maintained at 0.9 MPa at a reaction temperature of 80 ° C. Hydrogenation proceeded immediately with exotherm, the temperature was lowered at 4 hours after the start of the reaction, and the reaction was stopped. Then, after depressurizing and taking out the contents, the reaction product was subjected to simple distillation to separate a fraction (target compound) having a distillation temperature of 240 to 270 ° C. and a pressure of 530 Pa.
This mPAO-2 had a flash point [FP] of 230 ° C. and a 40 ° C. kinematic viscosity [ν] of 13.97 mm ² / s.

Production Example 3
An α-olefin oligomer hydrogenated product (mPAO-3) using a metallocene catalyst was produced according to the following method.
(A) Dimerization of decene In a three-necked flask with an internal volume of 5 liters substituted with nitrogen, 3.0 kg of 1-decene, 0.9 g of bis (cyclopentadienyl) zirconium dichloride which is a metallocene complex (also called zirconocene dichloride) (3 mmol) and methylaluminoxane (manufactured by Albemarle, 8 mmol in terms of Al) were sequentially added, and the mixture was stirred at room temperature (20 ° C. or lower). The reaction solution changed from yellow to reddish brown. After 48 hours from the start of the reaction, methanol was added to stop the reaction, and then an aqueous hydrochloric acid solution was added to the reaction solution to wash the organic layer. Next, the organic layer was vacuum distilled to obtain 2.5 kg of a fraction (decene dimer) having a boiling point of 120 to 125 ° C./26.6 Pa (0.2 Torr). When this fraction was analyzed by gas chromatography, the concentration of decene dimer was 99% by mass, and the vinylidene olefin ratio in the decene dimer was 97% by mass.
(B) Dimerization and hydrogenation step of decene dimerization product 2.5 kg of the dimer obtained in the previous section and 250 g of montmorillonite K-10 (manufactured by Aldrich) were added to a nitrogen-substituted 5 L three-necked flask at room temperature. After mixing, the temperature was raised to 110 ° C. with stirring, and the reaction was performed at that temperature for 9 hours. Then, the temperature was lowered and the catalyst montmorillonite was filtered off at room temperature. Next, the dimerization reaction product was transferred to an autoclave with an internal volume of 5 L, 5 g palladium / alumina 5 g was added thereto, and then purged with nitrogen. Further, after hydrogen substitution, the temperature was raised to a hydrogen pressure of 0.8 MPa. The hydrogenation reaction was carried out for 8 hours. After confirming that no more hydrogen absorption occurred, the temperature was lowered and the pressure was released, and the hydrogenated product was taken out of the autoclave. The catalyst was separated from the hydrogenated product by filtration to obtain 2.2 kg of a colorless transparent oily product. When the oily substance was analyzed by gas chromatography, saturated hydrocarbons having 20 carbon atoms, 40 carbon atoms, and 60 carbon atoms were produced in proportions of 45 mass%, 52 mass%, and 3 mass%, respectively.
(C) Isolation and identification of hydrogenated product 2.2 kg of the oily substance described above is transferred to a 5 L internal volume distillation flask immersed in a silicone oil bath, the degree of vacuum is 26.6 Pa (0.2 torr), and the oil bath is kept at room temperature. The temperature was raised to 150 ° C. and distillation under reduced pressure was performed. After distilling off the saturated hydrocarbon having 20 carbon atoms at 150 ° C., the temperature was further raised and the pressure was reduced at 190 ° C. and 26.6 Pa (0.2 torr) for 30 minutes. The distillation residue (target compound) was 1.2 kg (crude yield of all steps: 40%). When this was analyzed by gas chromatography, the hydrocarbon having 20 carbon atoms was 0.3% by mass, the hydrocarbon having 40 carbon atoms was 92.7% by mass, and the hydrocarbon having 60 carbon atoms was 7.0% by mass. there were.
The flash point [FP] of this mPAO-3 was 264 ° C., and the kinematic viscosity [ν] at 40 ° C. was 41.77 mm ² / s.

Examples 1-3 and Comparative Examples 1-8
Each heat-treated oil composed of a base oil having a flash point and a 40 ° C. kinematic viscosity shown in Table 1 was evaluated for its cooling performance. The results are shown in Table 1.

(note)
1) mPAO-1: hydrogenated product of α-olefin oligomer obtained using metallocene catalyst obtained in Production Example 1 2) mPAO-2: α-olefin oligomer produced using metallocene catalyst obtained in Production Example 2 3) mPAO-3: hydrogenated product of α-olefin oligomer obtained using metallocene catalyst obtained in Production Example 3 4) mineral oil-1: paraffinic mineral oil 5) mineral oil-2: paraffinic mineral oil 6 ) Mineral oil-3: Paraffinic mineral oil 7) Mineral oil-4: Paraffinic mineral oil 8) PAO-1: 1-decene oligomer obtained using an acid catalyst according to a conventional method [trade name “Idemitsu Kogyo Co., Ltd. PAO-5002 "]
9) PAO-2: 1-decene oligomer obtained by a conventional method using an acid catalyst [trade name “Idemitsu PAO-5004” manufactured by Idemitsu Kosan Co., Ltd.]
10) PAO-3: 1-decene oligomer obtained by a conventional method using an acid catalyst [trade name “Idemitsu PAO-5006” manufactured by Idemitsu Kosan Co., Ltd.]
11) PAO-4: 1-decene oligomer obtained by a conventional method using an acid catalyst [trade name “Idemitsu PAO-5010” manufactured by Idemitsu Kosan Co., Ltd.]

Examples 4-6 and Comparative Examples 9-16
Each heat-treated oil comprising 95% by mass of the base oil shown in Table 2 and 5% by mass of PAS (asphaltum) [trade name “NC-505” manufactured by Nippon Chemicals Co., Ltd.], which is a vapor film breaker, is cooled. Sex was evaluated. The results are shown in Table 2.

（注）
１）〜１１）は、第１表の脚注と同じである。

(note)
1) to 11) are the same as the footnotes in Table 1.

  As can be seen from Tables 1 and 2, the heat-treated oils of the present invention (Examples 1 to 6) maintain good cooling properties, have a high flash point, and reduce the risk of fire.

  The heat-treated oil of the present invention includes a base oil mainly composed of an α-olefin oligomer compound, and has a good cooling property, a high flash point, and a low risk of fire in a treatment such as quenching of a metal material. It has the features such as.

Claims (10)

The α-olefin oligomer compound is contained in an amount of 70% by mass or more, and the flash point FP (° C.) and the 40 ° C. kinematic viscosity ν (mm ² / s) are expressed by the formula (1)
FP ≧ 250loglogν + 200 (1)
A heat-treated oil characterized by containing a base oil that satisfies the above relationship. The heat-treated oil according to claim 1, wherein the base oil has a 40 ° C. kinematic viscosity of 4 to 100 mm ² / s.   The heat-treated oil according to claim 1 or 2, comprising a vapor film breaker. The α-olefin oligomer compound is at least one selected from compounds having 8 to 72 carbon atoms and having a structure represented by the following formulas (2) to (8). The heat-treated oil as described.

[Wherein, p, q and r each independently represent an integer of 0 to 18, n represents an integer of 0 to 8, and when n is 2 or more, q may be the same or different for each repeating unit, The value of p + n × (2 + q) + r is 4 to 52.
a, b and c are each independently an integer of 0 to 18, m is an integer of 0 to 8, and when m is 2 or more, b may be the same or different for each repeating unit, and a + m × (2 + b ) The value of + c is 4 to 52.
R ^{1 to} R ¹² each independently represent a hydrogen atom or a linear or branched alkyl group having ¹ to 16 carbon atoms, the total carbon number of R ^{1 to} R ^{4 and} the total carbon number of R ^{5 to} R ^8. and the total number of carbon atoms in R ⁹ to R ¹² are each an integer of 0 to 64.
R ¹³ and R ¹⁶ are each a straight chain or branched alkyl group having 2 to 22 carbon atoms, R ¹⁴ , R ¹⁵ , R ¹⁷ and R ¹⁸ are each independently a hydrogen atom or a straight chain having 1 to 22 carbon atoms. or an alkyl group having a branched, total number of carbon atoms of R ¹³ to R ¹⁵ and the total number of carbon atoms of R ¹⁶ to R ¹⁸ are each an integer of 2-66. ]   The α-olefin oligomer compound represented by the formula (2) is an α-olefin oligomer having 8 to 72 carbon atoms obtained by oligomerizing an α-olefin having 2 to 20 carbon atoms using a metallocene catalyst. The heat-treated oil according to claim 4.   Hydrogen of α-olefin oligomer having 8 to 72 carbon atoms obtained by oligomerizing α-olefin oligomer compound represented by formula (3) by using metallocene catalyst to oligomerize C2 to C20 α-olefin. The heat-treated oil according to claim 4, which is an additive.   The α-olefin oligomeric compounds represented by the formulas (4) and (5) are further dimerized from the vinylidene olefin obtained by dimerizing the α-olefin using a metallocene catalyst using an acid catalyst. The heat-treated oil according to claim 4, which is an α-olefin tetramer.   An α-olefin obtained by further dimerizing a vinylidene olefin obtained by dimerizing an α-olefin using a metallocene catalyst into an α-olefin oligomer compound represented by the formula (6) using an acid catalyst The heat-treated oil according to claim 4, which is a tetramer hydrogenated product.   The α-olefin oligomer compound represented by the formula (7) is a vinylidene olefin obtained by dimerizing an α-olefin using a metallocene catalyst, and an α-olefin having 4 to 24 carbon atoms using an acid catalyst. The heat-treated oil according to claim 4, which is a compound formed by adding an olefin.   The α-olefin oligomer compound represented by the formula (8) is a vinylidene olefin obtained by dimerizing an α-olefin using a metallocene catalyst, and an acid catalyst having a C 4-24 α- The heat-treated oil according to claim 4, which is a compound obtained by adding an olefin and further hydrogenating.