JP2018062576A - Method for producing oligomer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing an oligomer capable of sufficiently suppressing generation of a polymer of an α-olefin in oligomerization of a polymerizable monomer including an α-olefin.SOLUTION: There is provided a method for producing an oligomer which comprises a step of oligomerizing a polymerizable monomer containing an α-olefin having 6 or more carbon atoms in the presence of a catalyst comprising an iron compound represented by the following general formula (1) and a methylaluminoxane and/or a boron compound. [in the formula (1), R represents a hydrocarbyl group having 1 to 6 carbon atoms or an aromatic group having 6 to 12 carbon atoms and a plurality of R in the same molecule may be the same or different from each other; R' represents a free radical having an oxygen atom and/or a nitrogen atom and a plurality of R' in the same molecule may be the same or different from each other; and Y represents a chlorine atom or a bromine atom.]SELECTED DRAWING: None

Description

  The present invention relates to a method for producing an oligomer, and specifically relates to a method for producing an oligomer from a monomer containing an α-olefin having 6 or more carbon atoms.

  As a catalyst used for copolymerization of ethylene and α-olefin, a catalyst comprising a metallocene compound and methylaluminoxane, a palladium-based catalyst, an iron complex, a cobalt complex and the like are known (for example, Non-Patent Documents 1 to 3 and (See Patent Documents 1 to 3). Iron complexes are also known as ethylene polymerization catalysts. (For example, refer to the following non-patent documents 4 to 6).

  Moreover, poly (alpha) -olefin (PAO) manufactured from the alpha-olefin using the metallocene compound as a base oil of lubricating oil is known (for example, refer the following patent document 4). Propylene is mentioned as a typical alpha olefin used for manufacture of the conventional PAO.

Special Table 2000-516295 JP 2002-302510 A Chinese Patent Application No. 10243415 JP 2011-121991 A

“Macromol. Chem. Phys.”, 197, 1996, p. 3907 “J. Am. Chem. Soc.”, 117, 1995, p. 6414 “J. Am. Chem. Soc.”, 120, 1998, p. 7143 “J. Mol. Cat. A: Chemical”, 179, 2002, p. 155 “Appl. Cat. A: General”, 403, 2011, p. 25 “Organometallics”, 28, 2009, p. 3225

  Lubricating oils are widely used as lubricants for industrial products typified by automobiles, but particularly when used in automobiles, lowering the viscosity of lubricating oils is desired from the viewpoint of improving fuel saving characteristics.

  However, PAO produced from an α-olefin using a metallocene compound usually contains a highly polymerized α-olefin having a high viscosity. For this reason, when conventional PAO is used as a base oil of a lubricating oil composition, it is necessary to remove such a high viscosity α-olefin polymer by distillation purification and reduce the viscosity. It is difficult to reduce the viscosity without impairing the performance of the resin.

  This invention is made | formed in view of such a situation, In the oligomerization of the polymerizable monomer containing an alpha olefin, the production | generation of the oligomer which can fully suppress the production | generation of the highly polymerized alpha olefin is demonstrated. An object is to provide a manufacturing method.

［式（１）中、Ｒは炭素数１〜６のヒドロカルビル基または炭素数６〜１２の芳香族基を示し、同一分子中の複数のＲは同一でも異なっていてもよく、Ｒ’は酸素原子および／または窒素原子を有する遊離基を示し、同一分子中の複数のＲ’は同一でも異なっていてもよく、Ｙは塩素原子または臭素原子を示す。］ That is, the present invention provides a polymerizable monomer containing an α-olefin having 6 or more carbon atoms in the presence of a catalyst containing an iron compound represented by the following general formula (1) and a methylaluminoxane and / or boron compound. Provided is a method for producing an oligomer, comprising the step of oligomerization.

[In the formula (1), R represents a hydrocarbyl group having 1 to 6 carbon atoms or an aromatic group having 6 to 12 carbon atoms, a plurality of R in the same molecule may be the same or different, and R ′ represents oxygen A free radical having an atom and / or a nitrogen atom is represented, and a plurality of R ′ in the same molecule may be the same or different, and Y represents a chlorine atom or a bromine atom. ]

  According to the said manufacturing method, the high polymerization thing of the alpha olefin in a reaction product can fully be reduced. The polymerizable monomer used in the production method includes an α-olefin having 6 or more carbon atoms, which is larger than propylene used in the production of conventional PAO. By oligomerizing the polymerizable monomer in the presence of the specific catalyst, it is possible to efficiently obtain the target oligomer while suppressing excessive progress of the polymerization reaction. Therefore, an oligomer having a molecular weight comparable to that of conventional PAO can be efficiently obtained with a degree of polymerization smaller than that of conventional PAO, and α-olefin polymerization reaction than propylene used in the production of conventional PAO. It is possible to suppress the excessive progression of.

  The polymerizable monomer may contain an α-olefin having 8 or more carbon atoms.

  The oligomer obtained in the above step may contain an α-olefin dimer and / or trimer. In this case, the sum of the content ratios of the α-olefin dimer and trimer contained in the oligomer can be 70% by mass or more based on the total mass of the oligomer.

  ADVANTAGE OF THE INVENTION According to this invention, in the oligomerization of the polymerizable monomer containing an alpha olefin, the production method of the oligomer which can fully suppress the production | generation of the high polymerization product of an alpha olefin is provided.

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

  The oligomer production method according to this embodiment includes a step of oligomerizing a polymerizable monomer containing an α-olefin having 6 or more carbon atoms in the presence of a catalyst. The catalyst for oligomerization includes an iron compound and a methylaluminoxane and / or boron compound.

  In the present embodiment, the iron compound is represented by the following general formula (1).

  In the formula (1), R represents a hydrocarbyl group having 1 to 6 carbon atoms or an aromatic group having 6 to 12 carbon atoms, and a plurality of R in the same molecule may be the same or different. R ′ represents a radical having an oxygen atom and / or a nitrogen atom, and a plurality of R ′ in the same molecule may be the same or different. Y represents a chlorine atom or a bromine atom.

  As a C1-C6 hydrocarbyl group, a C1-C6 alkyl group, a C2-C6 alkenyl group, etc. are mentioned. The hydrocarbyl group may be linear, branched or cyclic. Furthermore, the hydrocarbyl group may be a monovalent group in which a linear or branched hydrocarbyl group and a cyclic hydrocarbyl group are bonded.

  Examples of the alkyl group having 1 to 6 carbon atoms include linear alkyl groups having 1 to 6 carbon atoms such as methyl group, ethyl group, n-propyl group, n-butyl group, n-pentyl group, and n-hexyl group; -Propyl group, iso-butyl group, sec-butyl group, tert-butyl group, branched pentyl group (including all structural isomers), branched hexyl group (including all structural isomers), etc. Examples thereof include branched alkyl groups having 3 to 6 carbon atoms; cyclic alkyl groups having 1 to 6 carbon atoms such as cyclopropyl group, cyclobutyl group, cyclopentyl group, and cyclohexyl group.

  As a C2-C6 alkenyl group, C2-C6 linear alkenyl groups, such as an ethenyl group (vinyl group), n-propenyl group, n-butenyl group, n-pentenyl group, n-hexenyl group; Carbon such as iso-propenyl group, iso-butenyl group, sec-butenyl group, tert-butenyl group, branched pentenyl group (including all structural isomers), branched hexenyl group (including all structural isomers), etc. A branched alkenyl group having 2 to 6 carbon atoms; a cyclic alkenyl group having 2 to 6 carbon atoms such as a cyclopropenyl group, a cyclobutenyl group, a cyclopentenyl group, a cyclopentadienyl group, a cyclohexenyl group, and a cyclohexadienyl group. .

  Examples of the aromatic group having 6 to 12 carbon atoms include phenyl group, toluyl group, xylyl group, and naphthyl group.

  In the formula (1), a plurality of R in the same molecule may be the same or different, but may be the same from the viewpoint of simplifying the synthesis of the compound.

  The free radical having an oxygen atom and / or a nitrogen atom may be a free radical having 0 to 6 carbon atoms having an oxygen atom and / or a nitrogen atom. For example, a methoxy group, an ethoxy group, an isopropoxy group, a nitro group Etc.

  Specific examples of such iron compounds include compounds represented by the following formulas (1a) to (1h). These iron compounds can be used individually by 1 type or in combination of 2 or more types.

  In the iron compound represented by the general formula (1), a compound constituting the ligand (hereinafter sometimes referred to as a diimine compound) is obtained by, for example, dehydrating condensation of benzoylpyridine and an aniline compound in the presence of an acid. Can be synthesized.

  A preferred embodiment of the method for producing the diimine compound includes a first step in which 2,6-benzoylpyridine, an aniline compound, and an acid are dissolved in a solvent, and dehydration condensation is performed under solvent heating and reflux, and a reaction mixture after the first step. A second step of performing a separation / purification treatment to obtain a diimine compound.

  As the acid used in the first step, for example, an organoaluminum compound can be used. Examples of organoaluminum compounds include trimethylaluminum, triethylaluminum, tripropylaluminum, triisopropylaluminum, tributylaluminum, triisobutylaluminum, trihexylaluminum, trioctylaluminum, diethylaluminum chloride, ethylaluminum chloride, ethylaluminum sesquichloride, methylaluminoxane. Etc.

  As the acid used in the first step, a protonic acid can be used in addition to the organoaluminum compound. Protic acid is used as an acid catalyst for donating protons. The proton acid used is not particularly limited, but is preferably an organic acid. Examples of such a protonic acid include acetic acid, trifluoroacetic acid, methanesulfonic acid, trifluoromethanesulfonic acid, paratoluenesulfonic acid, and the like. When using these protonic acids, it is preferable to remove water with a Dean-Stark water separator or the like from the viewpoint of suppressing water by-generation. It is also possible to carry out the reaction in the presence of an adsorbent such as molecular sieves. The addition amount of the protonic acid is not particularly limited, and may be a catalytic amount.

  Examples of the solvent used in the first step include hydrocarbon solvents and alcohol solvents. Examples of the hydrocarbon solvent include hexane, heptane, octane, benzene, toluene, xylene, cyclohexane, methylcyclohexane, and the like. Examples of the alcohol solvent include methanol, ethanol, isopropyl alcohol, and the like.

  The reaction conditions in the first step can be appropriately selected according to the types and amounts of the raw material compound, acid and solvent.

  In addition, the separation / purification treatment in the second step is not particularly limited, and examples thereof include silica gel column chromatography and a recrystallization method. In particular, when the above-described organoaluminum compound is used as the acid, it is preferable to purify after mixing the reaction solution with a basic aqueous solution to decompose and remove aluminum.

The iron compound in this embodiment contains iron as a central metal. The method for mixing the diimine compound and iron is not particularly limited. For example,
(I) A method of adding and mixing an iron salt (hereinafter sometimes simply referred to as “salt”) to a solution in which a diimine compound is dissolved,
(Ii) a method of physically mixing a diimine compound and a salt without using a solvent;
Etc.

In addition, the method for taking out the complex from the mixture of the diimine compound and iron is not particularly limited, for example,
(A) a method of distilling off the solvent when a solvent is used in the mixture and filtering off the solid,
(B) a method of filtering the precipitate formed from the mixture,
(C) a method of purifying the precipitate by adding a poor solvent to the mixture and filtering it off;
(D) a method of taking out the solventless mixture as it is,
Etc. Thereafter, a washing treatment using a solvent capable of dissolving the diimine compound, a washing treatment using a solvent capable of dissolving the metal, a recrystallization treatment using an appropriate solvent, and the like may be performed.

  Examples of the iron salt include iron chloride (II), iron chloride (III), iron bromide (II), iron bromide (III), acetylacetone iron (II), acetylacetone iron (III), iron acetate (II) ), Iron (III) acetate, and the like. You may use what has ligands, such as a solvent and water, in these salts. Among these, a salt of iron (II) is preferable, and iron (II) chloride is more preferable.

  Moreover, it does not restrict | limit especially as a solvent which makes a diimine compound and iron contact, Any of a nonpolar solvent and a polar solvent can be used. Nonpolar solvents include hydrocarbon solvents such as hexane, heptane, octane, benzene, toluene, xylene, cyclohexane, and methylcyclohexane. Examples of the polar solvent include polar protic solvents such as alcohol solvents, polar aprotic solvents such as tetrahydrofuran, and the like. Examples of the alcohol solvent include methanol, ethanol, isopropyl alcohol, and the like. In particular, when the mixture is used as a catalyst as it is, it is preferable to use a hydrocarbon solvent that does not substantially affect olefin polymerization.

  Further, the mixing ratio of the diimine compound and iron when they are brought into contact with each other is not particularly limited. The diimine compound / iron ratio may be 0.2 / 1 to 5/1, 0.3 / 1 to 3/1, or 0.5 / 1 to 2/1 in molar ratio. , 1/1 may be used.

  The two imine sites in the diimine compound are preferably both E-forms, but may contain a diimine compound containing a Z-form as long as the diimine compound is an E-form. Since the diimine compound containing Z form is difficult to form a complex with a metal, it can be easily removed by a purification step such as solvent washing after forming a complex in the system.

  In this embodiment, the catalyst for oligomerization contains a methylaluminoxane and / or boron compound in addition to the iron compound represented by the general formula (1). Methylaluminoxane and a boron compound have a function as a promoter of the iron compound represented by the general formula (1).

  As the methylaluminoxane, a commercially available product diluted with a solvent can be used, and a product obtained by partially hydrolyzing trimethylaluminum in a solvent can also be used. When unreacted trimethylaluminum remains in the methylaluminoxane, the unreacted trimethylaluminum may be used as an organoaluminum compound described in detail below, or the trimethylaluminum and the solvent are distilled off under reduced pressure. It may be used as a dried methylaluminoxane. Further, in the partial hydrolysis of trimethylaluminum, modified methylaluminoxane obtained by co-hydrolysis by coexisting trialkylaluminum other than trimethylaluminum such as triisobutylaluminum can also be used. In this case as well, when there is residual trialkylaluminum, the unreacted trialkylaluminum may be used as an organoaluminum compound described in detail below, or the trialkylaluminum and the solvent are distilled off. It may be used as a dry modified methylaluminoxane.

  Examples of the boron compound include aryl boron compounds such as trispentafluorophenylborane. As the boron compound, a boron compound having an anionic species can be used. Examples thereof include aryl borates such as tetrakispentafluorophenyl borate and tetrakis (3,5-trifluoromethylphenyl) borate. Specific examples of the aryl borate include lithium tetrakis pentafluorophenyl borate, sodium tetrakis pentafluorophenyl borate, N, N-dimethylanilinium tetrakis pentafluorophenyl borate, trityl tetrakis pentafluorophenyl borate, lithium tetrakis (3,5-tri Fluoromethylphenyl) borate, sodium tetrakis (3,5-trifluoromethylphenyl) borate, N, N-dimethylanilinium tetrakis (3,5-trifluoromethylphenyl) borate, trityltetrakis (3,5-trifluoromethyl) Phenyl) borate and the like. Among these, N, N-dimethylanilinium tetrakispentafluorophenylborate, trityltetrakispentafluorophenylborate, N, N-dimethylanilinium tetrakis (3,5-trifluoromethylphenyl) borate or trityltetrakis (3,5 -Trifluoromethylphenyl) borate is preferred. These boron compounds can be used alone or in combination of two or more.

  In the present embodiment, the catalyst for oligomerization may further contain an optional component. Examples of the optional component include organoaluminum compounds other than methylaluminoxane.

  Specific examples of organoaluminum compounds other than methylaluminoxane include trimethylaluminum, triethylaluminum, triisopropylaluminum, tripropylaluminum, tributylaluminum, triisobutylaluminum, trihexylaluminum, triphenylaluminum, diethylaluminum chloride, ethylaluminum dichloride, Examples include ethylaluminum sesquichloride. These organoaluminum compounds can be used alone or in combination of two or more. By further including the organoaluminum compound, the olefin polymerization ability can be more effectively improved while sufficiently suppressing the production of a high α-olefin polymer.

  In this embodiment, when the catalyst for oligomerization contains the iron compound represented by the above general formula (1) and methylaluminoxane, the content ratio is G, methylaluminoxane. When the number of moles of aluminum atoms in Y is Y, the molar ratio may be G: Y = 1: 10 to 1: 1000 or 1:20 to 1: 500. If a content rate is in the said range, the factor of a cost increase can be suppressed, exhibiting desired polymerization activity.

  In the present embodiment, when the catalyst for oligomerization includes the iron compound represented by the general formula (1) and the boron compound, the content ratio thereof is when the number of moles of the boron compound is J, The molar ratio may be G: J = 0.1: 1 to 10: 1, or 0.5: 1 to 2: 1. If a content rate is in the said range, the factor of a cost increase can be suppressed, exhibiting desired polymerization activity. In addition, when the catalyst for oligomerization contains an iron compound and a boron compound, you may add especially operation which uses an alkyl complex about the said iron compound, or converts into an alkyl complex. For example, in the case of conversion to a methyl complex, an organoaluminum compound such as trimethylaluminum, an organozinc compound such as dimethylzinc, an organolithium compound such as methyllithium, and a grineer such as methylmagnesium chloride. The method of converting into a methyl complex of an iron compound is mentioned by making a compound etc. and the said iron compound contact.

  In addition, as a specific example of an organoaluminum compound, what was illustrated as organoaluminum compounds other than the said methylaluminoxane can be used, for example. Specific examples of the organic zinc compound include alkyl zinc such as dimethyl zinc and diethyl zinc, and aryl zinc such as diphenyl zinc. In addition, an organic zinc compound is reacted in a reaction system by reacting a zinc halide such as zinc chloride, zinc bromide or zinc iodide with an alkyllithium, arylgrineer, alkylgrineer, or the above organoaluminum compound. An organozinc compound may be formed. These organozinc compounds can be used alone or in combination of two or more.

  In this embodiment, when the catalyst for oligomerization contains the iron compound represented by the general formula (1), methylaluminoxane, and a boron compound, the iron compound and the aluminum atom in methylaluminoxane And the content ratio of the iron compound and the boron compound is, as a molar ratio, G: Y = 1: 1 to 1: 100 and G: J = 1: 1 to 1:10. Alternatively, G: Y = 1: 1 to 1:50, and G: J = 1: 1 to 1: 2. If a content rate is in the said range, the factor of a cost increase can be suppressed, exhibiting desired polymerization activity. Furthermore, as described above, the conversion of an iron compound into an alkyl complex can be simultaneously performed.

  In addition, the manufacturing method of the catalyst which concerns on this embodiment is not restrict | limited in particular, For example, the solution containing a methylaluminoxane and / or a boron compound is added to the solution containing the iron compound represented by General formula (1) mentioned above, The method of mixing, the method of adding and mixing the solution containing a methylaluminoxane and / or a boron compound, etc. are mentioned. In addition, when the above-described optional component is included, the iron compound, methylaluminoxane and / or boron compound represented by the general formula (1), and the optional component may be brought into contact at the same time. You may contact in the order of. Examples of the method for producing a catalyst according to this embodiment include a method in which a methylaluminoxane is brought into contact with a solution containing an iron compound represented by the general formula (1) and then brought into contact with a boron compound.

  The catalyst according to the present embodiment may further contain a compound represented by the following general formula (2) (hereinafter sometimes referred to as a ligand) as necessary.

  In formula (2), R ″ represents a hydrocarbyl group having 1 to 6 carbon atoms or an aromatic group having 6 to 12 carbon atoms, and a plurality of R ″ in the same molecule may be the same or different. "" Represents a radical having an oxygen atom and / or a nitrogen atom, and a plurality of R '"in the same molecule may be the same or different.

  By further including such a ligand, the catalyst efficiency can be further improved while sufficiently suppressing the formation of a high α-olefin polymer, and the polymerization activity can be maintained for a long time.

  As a C1-C6 hydrocarbyl group, a C1-C6 alkyl group, a C2-C6 alkenyl group, etc. are mentioned. The hydrocarbyl group may be linear, branched or cyclic. Furthermore, the hydrocarbyl group may be a monovalent group in which a linear or branched hydrocarbyl group and a cyclic hydrocarbyl group are bonded.

  Examples of the alkyl group having 1 to 6 carbon atoms include linear alkyl groups having 1 to 6 carbon atoms such as methyl group, ethyl group, n-propyl group, n-butyl group, n-pentyl group, and n-hexyl group; -Propyl group, iso-butyl group, sec-butyl group, tert-butyl group, branched pentyl group (including all structural isomers), branched hexyl group (including all structural isomers), etc. Examples thereof include branched alkyl groups having 3 to 6 carbon atoms; cyclic alkyl groups having 1 to 6 carbon atoms such as cyclopropyl group, cyclobutyl group, cyclopentyl group, and cyclohexyl group.

  As a C2-C6 alkenyl group, C2-C6 linear alkenyl groups, such as an ethenyl group (vinyl group), n-propenyl group, n-butenyl group, n-pentenyl group, n-hexenyl group; Carbon such as iso-propenyl group, iso-butenyl group, sec-butenyl group, tert-butenyl group, branched pentenyl group (including all structural isomers), branched hexenyl group (including all structural isomers), etc. A branched alkenyl group having 2 to 6 carbon atoms; a cyclic alkenyl group having 2 to 6 carbon atoms such as a cyclopropenyl group, a cyclobutenyl group, a cyclopentenyl group, a cyclopentadienyl group, a cyclohexenyl group, and a cyclohexadienyl group. .

  Examples of the aromatic group having 6 to 12 carbon atoms include phenyl group, toluyl group, xylyl group, and naphthyl group.

  In the formula (2), a plurality of R ″ in the same molecule may be the same or different, but may be the same from the viewpoint of simplifying the synthesis of the compound.

  The free radical having an oxygen atom and / or a nitrogen atom may be a free radical having 0 to 6 carbon atoms having an oxygen atom and / or a nitrogen atom, such as a methoxy group, an ethoxy group, an isopropoxy group, a nitro group. Groups and the like.

  Specific examples of such a ligand include compounds represented by the following formulas (2a) to (2d). These ligands can be used alone or in combination of two or more.

  Further, in the iron compound represented by the general formula (1) and the compound represented by the general formula (2) included in the catalyst according to the present embodiment, R in the general formula (1) and the general formula (2) R ″ and R ′ ″ in the general formula (1) and R ′ ″ in the general formula (2) may be the same as or different from each other, but the iron compound represented by the general formula (1) From the viewpoint of maintaining the same performance, it is preferable that they are the same.

  The compound represented by the general formula (2) can be synthesized by the same method as that for the diimine compound described above, and redundant description is omitted here.

  In the catalyst according to this embodiment, the content ratio of the iron compound represented by the general formula (1) and the ligand is not particularly limited. For example, the ligand / iron compound ratio may be 1/100 to 100/1, 1/20 to 50/1, or 1/10 to 10/1 in molar ratio. 1/5 to 5/1, or 1/3 to 3/1. If the ratio of the ligand / iron compound is 1/100 or more, the effect of adding the ligand can be sufficiently exerted, and if it is 100/1 or less, the effect of adding the ligand can be exhibited and the cost can be suppressed. .

  In the catalyst in the present embodiment, the order of addition of the compound in the case where the compound represented by the general formula (2) is further included is not particularly limited. For example, methylaluminoxane and / or the solution containing the iron compound and the ligand described above are added. Alternatively, a method of adding and mixing a solution containing a boron compound, a method of adding and mixing a solution containing a ligand to a solution containing an iron compound and methylaluminoxane and / or boron compound, and the like can be mentioned.

  The method for producing an oligomer in the present embodiment includes a step of oligomerizing a polymerizable monomer containing an α-olefin having 6 or more carbon atoms in the presence of the catalyst according to the present embodiment described above.

  The polymerizable monomer is not particularly limited as long as it contains an α-olefin having 6 or more carbon atoms. For example, when the physical properties of the obtained oligomer are taken into consideration, the polymerizable monomer contains an α-olefin having 8 or more carbon atoms. It may be one containing an α-olefin having 10 or more carbon atoms. Further, the upper limit of the carbon number of the α-olefin is not particularly limited, but may be, for example, 18 or less from the viewpoint of reactivity. Examples of such α-olefins include 1-hexene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene and the like. Among these, considering the reactivity and physical properties of the resulting oligomer, at least one selected from the group consisting of 1-hexene, 1-octene, 1-decene and 1-dodecene is preferable. These α-olefins can be used alone or in combination of two or more.

  The polymerizable monomer used in the present embodiment may be composed of one kind of α-olefin having 6 or more carbon atoms, or may be composed of two or more kinds of α-olefin having 6 or more carbon atoms. Further, a monomer other than the α-olefin having 6 or more carbon atoms may be further contained. Further, as one aspect of the production method according to the present embodiment, a method of introducing a polymerizable monomer into a reaction apparatus filled with a catalyst can be mentioned. The method for introducing the polymerizable monomer into the reaction apparatus is not particularly limited, and in the case of a monomer mixture containing two or more polymerizable monomers, the monomer mixture may be introduced into the reaction apparatus, or each polymerizable property Monomers may be introduced separately.

  Moreover, you may use a solvent in the case of oligomerization. The solvent is not particularly limited, but a nonpolar solvent may be used from the viewpoint of favorably performing the polymerization reaction. Examples of the nonpolar solvent include normal hexane, isohexane, heptane, octane, isooctane, cyclohexane, methylcyclohexane, benzene, toluene, xylene and the like. These solvents can be recovered and reused simultaneously with the unreacted α-olefin when the oligomerization reaction is performed.

  Although the reaction temperature in the case of oligomerization is not specifically limited, For example, 0-100 degreeC may be sufficient, 10-90 degreeC may be sufficient, and 20-80 degreeC may be sufficient. If reaction temperature is 0 degreeC or more, it can react efficiently, without requiring enormous energy for cooling, and if it is 100 degrees C or less, the activity fall of an iron compound can be suppressed. Also, the reaction pressure is not particularly limited, but may be, for example, 100 kPa to 1 MPa. In pressurization, an inert gas such as nitrogen may be used. In addition, when a sealed container is used for a reactor, the vapor | steam generate | occur | produced from the raw material and solvent to be used may raise reactor pressure, but you may react, maintaining the pressure.

  The oligomer obtained by the oligomerization may be a homopolymer of one kind of the α-olefin having 6 or more carbon atoms, or may be a copolymer of two or more kinds. Such an oligomer may be, for example, a homopolymer of 1-hexene, a homopolymer of 1-octene, a homopolymer of 1-decene, or 1-dodecene. The homopolymer of 1-octene and 1-decene may be sufficient. Furthermore, the oligomer may further contain a structural unit derived from a monomer other than the α-olefin having 6 or more carbon atoms. Examples of the monomer other than the α-olefin having 6 or more carbon atoms include polar olefins having a substituent such as ester, amide, and nitrile.

  The oligomer obtained by oligomerization may contain the dimer and / or trimer of the α-olefin. The total content of dimer and trimer in the resulting oligomer may be, for example, 70% by mass or more, 80% by mass or more, based on the total mass of the oligomer, It may be 90% by mass or more. Considering the physical properties of the obtained oligomer, the oligomer is preferably composed of the above α-olefin dimer and / or trimer. In addition, the content ratio of the dimer and the trimer in the obtained oligomer can be determined by using an internal standard method by gas chromatography as described later, for example.

  Moreover, the number average molecular weight (Mn) of the oligomer obtained by oligomerization can be suitably adjusted according to the use. For example, when the oligomer is used as a lubricating oil, the Mn of the oligomer may be, for example, 100 to 1000, 200 to 800, 250 to 700, or 300 to 600. May be. The dispersity is a ratio of the weight average molecular weight (Mw) to Mn, and is expressed as Mw / Mn. For example, it may be 1.0 to 2.0, or 1.0 to 1.5. It may be. In addition, Mn and Mw of the oligomer can be obtained, for example, by using an internal standard method by gas chromatography to be described later, or obtained as a polystyrene equivalent amount based on a calibration curve created from standard polystyrene using a GPC apparatus. You can also.

  The manufacturing method according to the present embodiment is useful as a method for manufacturing a base material for lubricating oil such as PAO. In addition, the oligomer obtained by the production method according to the present embodiment can be suitably used, for example, as a base oil component of a lubricating oil composition, and in particular, a lubricating oil composition for automobiles and the like for which low viscosity is desired. It can be suitably used as a base oil.

  The following examples illustrate the invention, but the following examples are not intended to limit the invention.

[Preparation of materials]
The iron compound was synthesized by the method shown in the synthesis examples described later. The purchased reagents were used as they were. As the methylaluminoxane (hexane solution), TMAO-341 manufactured by Tosoh Finechem was used as it was. The trityl tetrakis pentafluorophenyl borate used as it was made by Tokyo Chemical Industry. As trimethylaluminum (toluene solution), a product made in Japan alkylaluminum was used as it was.

  As the solvent toluene, Aldrich dehydrated toluene was used as it was.

[Measurement of monomer conversion and oligomer selectivity]
A polymethylsiloxane column (manufactured by Agilent, product name: HP-1, length 30 m, diameter 320 μm, film thickness 0.25 μm) was connected to a GC apparatus (manufactured by Agilent, product name: 6850). Nitrogen was used as a carrier gas, and measurement was performed under the conditions of a linear velocity of 34 cm / s, a split ratio of 9: 1, and an inlet temperature of 300 ° C. The column oven was set to an initial temperature of 40 ° C., and the temperature was raised to 300 ° C. at 16 ° C./min. The sample was analyzed under such conditions, and the monomer conversion (mass%) was calculated from the area ratio of the initial α-olefin and the α-olefin after the reaction. Moreover, the selectivity (mass%) of a dimer, a trimer, etc. in the obtained oligomer was computed from each area ratio. In addition, it confirmed beforehand that the wax which has carbon number 20-40 distribution was detectable on the same GC conditions.

[Production Example 1: Synthesis of diimine compound (I)]
2-methyl-4-methoxyaniline (2.0893 g, 15.3 mmol, manufactured by Tokyo Chemical Industry), 2,6-diacetylpyridine (1.2429 g, 7.6 mmol, manufactured by Tokyo Chemical Industry), molecular sieve 4A (5.0 g) Then, a catalytic amount of para-toluenesulfonic acid was dispersed in dry toluene (60 ml) and stirred using a Dean-Stark water separator to heat and reflux for 24 hours while removing water.

  The molecular sieve was removed from the reaction solution by filtration, and the molecular sieve was washed with toluene. The washing liquid and the filtered reaction liquid were mixed and concentrated to dryness to obtain a crude solid (2.8241 g). The crude solid (2 g) obtained here was weighed and washed with absolute ethanol (30 ml). The ethanol-insoluble solid was filtered off, and the insoluble solid was further washed with ethanol. The remaining solid was sufficiently dried to obtain the following diimine compound (I) in a yield of 50%.

¹ H-NMR (600 MHz, CDCl ₃ ): 2.1 (s, 6H), 2.4 (s, 6H), 3.8 (s, 6H), 6.6 (m, 2H), 6.7 (M, 2H), 6.8 (m, 2H), 7.9 (m, 1H), 8.4 (m, 2H)
¹³ C-NMR (600 MHz, CDCl ₃ ): 16, 18, 56, 116, 119, 122, 125, 129, 137, 138, 143, 156, 167

[Production Example 2: Synthesis of iron compound (1a)]
FeCl ₂ .4H ₂ O (0.2401 g, 1.2 mmol, manufactured by Kanto Kagaku) was dissolved in dehydrated tetrahydrofuran (30 ml, manufactured by Aldrich), and the diimine compound (I) (0.4843 g, 1.2 mmol) synthesized earlier was dissolved. Of tetrahydrofuran (10 ml) was added. By adding a yellow diimine compound, a dark green tetrahydrofuran solution was instantaneously formed. Furthermore, it stirred at room temperature for 2 hours. The solvent was evaporated from the reaction solution to dryness, and the precipitated solid was washed with dehydrated ethanol until the filtrate had no color. Further, the washed solid was washed with dehydrated diethyl ether, and the solvent was removed to obtain an iron compound. Since the obtained iron compound obtained 527.0820 (calculated value: 527.0831) in FD-MASS, the structure of the following iron compound (1a) is suggested.

[Production Example 3: Synthesis of diimine compound (II)]
2-methyl-4-nitroaniline (1.048 g, 6.9 mmol, manufactured by Tokyo Chemical Industry), 2,6-diacetylpyridine (0.5618 g, 3.5 mmol, manufactured by Tokyo Chemical Industry), and a catalytic amount of para-toluenesulfonic acid. The mixture was dispersed in dry toluene (60 ml) and stirred using a Dean-Stark water separator to heat and reflux for 24 hours while removing water. After the start of heating, the dispersion immediately dissolved and became a uniform solution.

  The reaction solution was allowed to cool and the precipitated solid was filtered off. The obtained toluene solution was washed with saturated multistory water and saturated brine, and dried over anhydrous magnesium sulfate. The magnesium sulfate was separated by filtration, and toluene was removed under reduced pressure to precipitate a solid. The obtained solid was washed with ethanol to obtain the following diimine compound (II) in a yield of 30%.

¹ H-NMR (600 MHz, CDCl ₃ ): 2.2 (s, 6H), 2.3 (s, 6H), 6.8 (m, 2H), 8.0 (m, 1H), 8.1 (M, 4H), 8.4 (m, 2H)

[Production Example 4: Synthesis of iron compound (1c)]
FeCl ₂ .4H ₂ O (0.038 g, 0.19 mmol, manufactured by Kanto Chemical) was dissolved in dehydrated tetrahydrofuran (6 ml, manufactured by Aldrich), and the diimine compound (II) synthesized earlier (0.083 g, 0.19 mmol) Of tetrahydrofuran (5 ml) was added. By adding a yellow diimine compound, a dark green tetrahydrofuran solution was instantaneously formed. Furthermore, it stirred at room temperature for 2 hours. The solvent was evaporated from the reaction solution to dryness, and the precipitated solid was washed with dehydrated ethanol until the filtrate had no color. Further, the washed solid was washed with dehydrated diethyl ether, and the solvent was removed to obtain an iron compound. Since the obtained iron compound obtained 5557.0316 (calculated value: 557.0321) in FD-MASS, the structure of the following iron compound (1c) is suggested.

<Example 1>
Into a well-dried 100 ml eggplant-shaped flask, the iron compound (1a) (6.1 μmol) was introduced under a stream of nitrogen, dry toluene (41 g) was added, and a stirrer chip was added and stirred to obtain a solution (A1). It was. Methylaluminoxane (hexane solution, 3.0 mmol as Al) was added to the solution (A1) to obtain a solution (B1) containing a catalyst. To the solution (B1), 1-octene (33 mmol) was added and reacted at room temperature for 10 hours. A small amount of ethanol was added to the reaction solution, and the volatile component was distilled off with an evaporator. From the weight of the residue, the yield of oligomer was calculated to be 26% by mass. Moreover, when the residue was analyzed by gas chromatography and the selectivity was calculated, the dimer selectivity was 85 mass%, the trimer selectivity was 15 mass%, and no tetramer or more was detected. .

<Example 2>
The iron compound (1a) (16 μmol) was introduced into a well-dried 100 ml eggplant-shaped flask under a nitrogen stream, dry toluene (50 ml) was added, and a stirrer chip was added and stirred to obtain a solution (A2). . Methylaluminoxane (hexane solution, 8 mmol as Al) was added to the solution (A2) to obtain a solution (B2) containing a catalyst. To the solution (B2), 1-decene (89 mmol) was added and reacted at room temperature for 10 hours. A small amount of water was added to the reaction solution to deactivate the catalyst, and the supernatant was analyzed by gas chromatography to calculate the conversion rate of 1-decene and the selectivity of the oligomer. The conversion of 1-decene was 30% by mass, the dimer selectivity was 89% by mass, the trimer selectivity was 11% by mass, and no tetramer or more was detected.

<Example 3>
Into a well-dried 100 ml eggplant-shaped flask, the iron compound (1a) (7.4 μmol) was introduced under a nitrogen stream, dry toluene (50 ml) was added, and a stirrer chip was added and stirred to obtain a solution (A3). It was. Methylaluminoxane (hexane solution, 3.7 mmol as Al) was added to the solution (A3) to obtain a solution (B3) containing a catalyst. To the solution (B3), 1-dodecene (41 mmol) was added and reacted at room temperature for 10 hours. A small amount of water was added to the reaction solution to deactivate the catalyst, and the supernatant was analyzed by gas chromatography to calculate the conversion rate of 1-dodecene and the selectivity of the oligomer. The conversion of 1-dodecene was 18% by mass, the dimer selectivity was 94% by mass, the trimer selectivity was 6% by mass, and no tetramer or more was detected.

<Example 4>
The same operation as in Example 1 was performed except that the iron compound (1c) (8 μmol) was used instead of the iron compound (1a). The conversion of 1-octene was 22% by mass, the dimer selectivity was 85% by mass, the trimer selectivity was 15% by mass, and no tetramer or more was detected.

<Example 5>
An iron compound (1a) (8 μmol) and diimine compound (I) (3 μmol, ligand (2a)) as a ligand were introduced into a well-dried 100 ml eggplant-shaped flask under a nitrogen stream, and dried toluene (50 ml) Was added, and a stirrer chip was further added and stirred to obtain a solution (A5). Methylaluminoxane (hexane solution, 0.3 mmol as Al) was added to the solution (A5) to obtain a solution (B5) containing a catalyst. To the solution (B5), 1-decene (90 mmol) was added and reacted at room temperature for 10 hours. A small amount of water was added to the reaction solution to deactivate the catalyst, and the supernatant was analyzed by gas chromatography to calculate the conversion rate of 1-decene and the selectivity of the oligomer. The conversion of 1-decene was 30% by mass, the dimer selectivity was 89% by mass, the trimer selectivity was 11% by mass, and no tetramer or more was detected.

<Example 6>
Iron compound (1a) (6.1 μmol) and trityltetrakispentafluorophenylborate (61 μmol) were introduced into a well-dried 100 ml eggplant-shaped flask under a nitrogen stream, dry toluene (41 g) was added, and a stirrer chip was further added. And stirred to obtain a solution (A6). Trimethylaluminum (toluene solution, 0.6 mmol) was added to the solution (A6) to obtain a solution (B6) containing a catalyst. To the solution (B6), 1-octene (33 mmol) was added and reacted at room temperature for 10 hours. A small amount of ethanol was added to the reaction solution, and the volatile component was distilled off with an evaporator. From the weight of the residue, the yield of the oligomer was calculated as 25% by mass. Moreover, when the residue was analyzed by gas chromatography and the selectivity was calculated, the dimer selectivity was 84 mass%, the trimer selectivity was 16 mass%, and no tetramer or more was detected. .

<Comparative Example 1>
Ethylenebisindenylzirconium dichloride (6.1 μmol) was introduced into a well-dried 100 ml eggplant-shaped flask under a nitrogen stream, dry toluene (20 ml) was added, and a stirrer chip was added and stirred to obtain a solution (A7 ). Methylaluminoxane (hexane solution, 0.3 mmol as Al) was added to the solution (A7) to obtain a solution (B7) containing a catalyst. To the solution (B7), 1-decene (33 mmol) was added and reacted at room temperature for 20 hours. A small amount of water was added to the reaction solution to deactivate the catalyst, and the supernatant liquid was analyzed by gas chromatography. However, the polymerization reaction proceeded excessively, and the remaining 1-decene (conversion rate was 99% by mass). No product other than) was detected, and the oligomer selectivity could not be calculated.

Claims (4)

A step of oligomerizing a polymerizable monomer containing an α-olefin having 6 or more carbon atoms in the presence of a catalyst containing an iron compound represented by the following general formula (1) and a methylaluminoxane and / or boron compound; The manufacturing method of an oligomer.

[In the formula (1), R represents a hydrocarbyl group having 1 to 6 carbon atoms or an aromatic group having 6 to 12 carbon atoms, a plurality of R in the same molecule may be the same or different, and R ′ represents oxygen A free radical having an atom and / or a nitrogen atom is represented, and a plurality of R ′ in the same molecule may be the same or different, and Y represents a chlorine atom or a bromine atom. ]   The production method according to claim 1, wherein the polymerizable monomer contains an α-olefin having 8 or more carbon atoms.   The production method according to claim 1 or 2, wherein the oligomer obtained in the step contains a dimer and / or a trimer of the α-olefin.   The manufacturing method of Claim 3 whose sum total of the content rate of the said dimer and the said trimer which occupies for the said oligomer is 70 mass% or more on the basis of the total mass of the said oligomer.