KR102368349B1 - Alphaolefin oligomer having low short chain branching and method for preparating thereof - Google Patents

Abstract

상기 식 1에서, logM_n은 수평균분자량(Number-Average Molecular Weight; M_n)의 로그 값이고, 평균 SCB는 FT-IR 스페트럼으로부터, CH₃ 피크와 CH₂ 피크의 강도(Intensity) 비(I_CH3/I_CH2)이다.Disclosed are an alpha-olefin oligomer having little short-chain branching, which can be used as a base oil for lubricating oil, and a method for preparing the same. The present invention comprises the steps of preparing an alpha olefin oligomer primary reactant by polymerizing an alpha olefin monomer having 3 to 20 carbon atoms in the presence of an olefin polymerization catalyst composition, in the presence of an acid catalyst, all or part of the alpha olefin oligomer primary reactant ( preparing an alpha olefin oligomer by polymerizing the separated intermediate with an alpha olefin monomer having 3 to 20 carbon atoms, after preparing the alpha olefin oligomer, unreacted alpha olefin monomer and side reaction product A nickel (Ni) or cobalt (Co)-based catalyst; Or hydrogenation in the presence of a noble metal catalyst containing palladium (Pd) or platinum (Pt), wherein the alpha olefin oligomer has an OBI (Oligomer Braching Index) of 43 or less according to Formula 1 below. including a manufacturing method of
[Equation 1]

In Equation 1, logM _n is the log value of Number-Average Molecular Weight (M _n ), and the average SCB is the intensity ratio of the CH ₃ peak and the CH ₂ peak from the FT-IR spectrum ( I _CH3 /I _CH2 ).

Description

Alpha olefin oligomer having low short chain branching and manufacturing method thereof

The present invention relates to an alpha olefin oligomer having little short-chain branching and a method for preparing the same, and more particularly, to an alpha olefin oligomer having little short-chain branching, which can increase the yield of trimers and tetramers, which are the main active ingredients used in lubricating base oil. It relates to an olefin oligomer and a method for preparing the same.

In general, lubricating oil is composed of a lubricating base oil and an additive for improving physical properties, and the lubricating base oil is typically divided into mineral oil and synthetic oil. Mineral oil refers to naphthenic oil produced in the process of separating and refining crude oil, and synthetic oil refers to poly alpha olefin (PAO) produced by polymerizing alpha-olefin produced during petroleum refining. .

In the past, mineral oil was mainly used as a lubricating base oil, but as the industry develops, a lubricating oil with high performance is required due to the high performance, high output, and severe operating conditions of internal combustion engines and industrial machines. Compared to oil, it has a high viscosity index and excellent fluidity at low temperatures, providing a wide range of use environments in low-temperature environments, and the demand for polyalphaolefins with excellent shear stability is increasing. Accordingly, polyalphaolefin synthetic lubricants have been commercially produced through various research and development for decades, and industrial research to improve the performance of synthetic lubricants based on the oligomerization reaction of alphaolefins having 6 to 20 carbon atoms is also actively conducted. is becoming

A general method that can be used to prepare a high-quality polyalphaolefin synthetic lubricant is a method using a Friedel-Crafts catalyst such as aluminum trichloride or boron trifluoride, which is disclosed in US Pat. No. 4,041,098, and in US Pat. No. 8,143,467, ammonium and phosphorus A method for producing polyalphaolefin using an ionic liquid catalyst material such as phonium is disclosed. However, in the case of polyalphaolefin prepared through the above preparation method, skeletal isomerization occurs according to a cationic reaction mechanism, thereby generating various and complex structures. In particular, many methyl groups are generated at arbitrary positions along the carbon chain, and if a large number of such short chain branches are provided, there is a disadvantage in that the properties of the base oil of the polyalphaolefin are deteriorated.

As an alternative to overcoming the above disadvantages and producing high quality polyalphaolefin, a production method using a metallocene catalyst is disclosed in US 8,207,390. However, polyalphaolefin having excellent base oil properties can be prepared through the above method, but in the case of polyalphaolefin prepared using a metallocene catalyst, a significant amount of dimer is produced, and this dimer has low low temperature characteristics. And since it is not suitable as a lubricant due to its viscosity characteristics, there is a disadvantage in that profitability is lowered.

Dimers, trimers, tetramers, pentamers, and higher-order oligomers synthesized in order to obtain a composition having a desired viscosity in a conventional polyalphaolefin process used as a lubricating base oil are subjected to a vacuum distillation unit (VDU) using a vacuum distillation unit (VDU). Distilled to obtain a kinematic viscosity in the range of 2 cSt to 10 cSt at 100 °C. In particular, there is a large market for a synthetic lubricant base raw material having a kinematic viscosity of 4 cSt. In the manufacturing process, it is desirable to increase the content of a composition having a kinematic viscosity of 4 cSt at 100 ° C. It is more preferred to prepare a cSt composition. For 4 cSt prepared in 1-decene oligomerization, the main composition is trimers and tetramers, in particular trimers are present in high proportions.

Accordingly, the present inventors were studying to prepare an alpha olefin oligomer having high trimer and tetramer while having excellent physical properties, Shirayama group reported J. Polym. Sci. Focusing on the correlation between the distribution of LDPE molecules and the distribution of short-chain branches of various commercial products with different short-chain branches described in Part A. 1965, 3, 907-916, the generation of short short-chain branches is suppressed, resulting in excellent viscosity index, Specific factors such as NOACK evaporation and flash point have been improved, and an alpha olefin oligomer having high trimer and tetramer as an active ingredient of a synthetic lubricant and a method for manufacturing the same have been developed.

US 4,041,098 US 8,143,467 US 8,207,390

Accordingly, it is an object of the present invention to provide an alpha olefin oligomer in which the generation of short short chain branches satisfying low NOACK evaporation, high flash point, and high viscosity index is suppressed.

In addition, another object of the present invention is to provide a method for producing an alpha olefin oligomer in which the generation of short branched branches is suppressed in order to achieve the above physical properties.

Another object of the present invention is to provide a method for preparing a trimer and a tetramer in high yield in preparing the alpha olefin oligomer.

Another object of the present invention is to provide an alpha olefin oligomer having a kinematic viscosity of 4 cSt at 100° C. in which the reactant is removed in preparing the alpha olefin oligomer.

In order to achieve the above object, the present invention provides the steps of preparing an alpha olefin oligomer intermediate by polymerizing an alpha olefin monomer having 3 to 20 carbon atoms in the presence of an olefin polymerization catalyst composition, in the presence of an acid catalyst, the alpha olefin oligomer intermediate and Preparing an alpha olefin oligomer by polymerizing an alpha olefin monomer having 3 to 20 carbon atoms, after preparing the alpha olefin oligomer, unreacted alpha olefin monomer and an isomer of an alpha olefin monomer that is a side reaction product and an alpha olefin monomer are combined Removal of the formed dimer and residual dimer and the alpha olefin oligomer from which the unreacted alpha olefin monomer and side reaction products are removed is used as a nickel (Ni) or cobalt (Co)-based catalyst; or hydrogenation in the presence of a noble metal catalyst containing palladium (Pd) or platinum (Pt), wherein the alpha olefin oligomer has an OBI (Oligomer Braching Index) of 43 or less according to Formula 1 below. It provides a manufacturing method of

[Equation 1]

In Equation 1, logM _n is the log value of Number-Average Molecular Weight (M _n ), and the average SCB is the intensity ratio of the CH ₃ peak and the CH ₂ peak from the FT-IR spectrum ( I _CH3 /I _CH2 ).

In addition, in the alpha olefin oligomer formed by polymerization of an alpha olefin monomer having 3 to 20 carbon atoms, the alpha olefin oligomer has an alpha olefin oligomer having an OBI (Oligomer Braching Index) of 43 or less according to Formula 1, mineral oil, dispersant, antioxidant , an antiwear agent, an antifoam agent, a corrosion inhibitor, a detergent, a seal swelling agent, a viscosity improver, and combinations thereof.

The alpha olefin oligomer having little short-chain branching according to the present invention and a method for preparing the same suppress the generation of short-chain branches that deteriorate the physical properties of the lubricating base oil, and increase the content of trimers and tetramers that are easy to use as a lubricating base oil, and residual reactants It is possible to prepare an alpha olefin oligomer with a kinematic viscosity of 4 cSt at 100 ° C., and has a low OBI (Oligomer Branching Index) as a uniform molecular structure, improved thermal stability, oxidation stability, long service life, and low Alphaolefin oligomers with volatility and high viscosity index can be prepared.

Hereinafter, the present invention will be described in more detail.

The alpha olefin oligomer according to the present invention is prepared by polymerizing an alpha-olefin having 3 to 20 carbon atoms in the presence of an olefin polymerization catalyst composition to prepare an alpha olefin oligomer first reactant, and the whole of the prepared alpha olefin oligomer first reactant or An alpha olefin oligomer is prepared by polymerization of a trimer or less or a dimer with an alpha olefin monomer having 3 to 20 carbon atoms in the presence of an acid catalyst, wherein the alpha olefin oligomer has an OBI (Oligomer Braching Index) of 43 or less according to Formula 1 below. have a value

[Equation 1]

In Equation 1, logM _n is the log value of Number-Average Molecular Weight (M _n ), and the average SCB is the intensity ratio of the CH ₃ peak and the CH ₂ peak from the FT-IR spectrum ( I _CH3 /I _CH2 ).

The olefin polymerization catalyst composition may be composed of a metallocene compound (A), an activator compound (B), and an auxiliary activator compound (C), which will be described in detail as follows.

Metallocene compound (A)

The metallocene compound (A) according to the present invention may be one or more selected from the group consisting of compounds represented by the following Chemical Formulas 1 to 6.

In Formulas 1 to 4, M is a transition metal selected from titanium, zirconium or hafnium,

B is an alkylene group having 1 to 20 carbon atoms, an arylene group having 6 to 20 carbon atoms, dialkyl silicon having 1 to 20 carbon atoms, dialkyl germanium having 1 to 20 carbon atoms, an alkylphosphine group having 1 to 20 carbon atoms, or an alkylphosphine group having 1 to 20 carbon atoms. A linking group of an alkylamine group or a form without a linking group,

X ₁ and X ₂ are each independently a halogen atom, an alkyl group having 1 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, an alkynyl group having 2 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, an alkyl group having 7 to 40 carbon atoms an aryl group, an arylalkyl group having 7 to 40 carbon atoms, an alkylamido group having 1 to 20 carbon atoms, an arylamido group having 6 to 20 carbon atoms, an alkylidene group having 1 to 20 carbon atoms, or an alkoxy group having 1 to 20 carbon atoms;

R ₁ to R ₁₀ are each independently hydrogen, an alkyl group having 1 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, an alkylaryl group having 7 to 20 carbon atoms, an arylalkyl group having 7 to 20 carbon atoms , a cycloalkyl group having 5 to 60 carbon atoms, a heterocyclic group having 4 to 20 carbon atoms, an alkynyl group having 1 to 20 carbon atoms, or a hetero or silyl group containing an aryl group having 6 to 20 carbon atoms.

In Formulas 5 and 6, M is a transition metal selected from titanium, zirconium, and hafnium,

B is an alkylene group having 1 to 20 carbon atoms, an arylene group having 6 to 20 carbon atoms, dialkyl silicon having 1 to 20 carbon atoms, dialkyl germanium having 1 to 20 carbon atoms, an alkylphosphine group having 1 to 20 carbon atoms, or an alkylphosphine group having 1 to 20 carbon atoms. In the form of an alkylamine linking group or no linking group,

X ₁ and X ₂ are each independently a halogen atom, an alkyl group having 1 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, an alkynyl group having 2 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, alkylaryl having 7 to 40 carbon atoms group, an arylalkyl group having 7 to 40 carbon atoms, an alkylamido group having 1 to 20 carbon atoms, an arylamido group having 6 to 20 carbon atoms, an alkylidene group having 1 to 20 carbon atoms, or an alkoxy group having 1 to 20 carbon atoms,

R ₁ to R ₁₀ are each independently hydrogen, an alkyl group having 1 to 20 carbon atoms, alkenyl having 2 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, an alkylaryl group having 7 to 20 carbon atoms, an arylalkyl group having 7 to 20 carbon atoms , a cycloalkyl group having 5 to 60 carbon atoms, a heterocyclic group having 4 to 20 carbon atoms, an alkynyl group having 1 to 20 carbon atoms, or a hetero or silyl group containing an aryl group having 6 to 20 carbon atoms.

R ₁₁ , R ₁₃ and R ₁₄ are the same hydrogen as each other, and R ₁₂ are each independently hydrogen, an alkyl group having 1 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, and an aryl group having 7 to 20 carbon atoms. A hetero group or silyl containing an alkylaryl group, an arylalkyl group having 7 to 20 carbon atoms, a cycloalkyl group having 5 to 60 carbon atoms, a heterocyclic group having 4 to 20 carbon atoms, an alkynyl group having 1 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms it's gi

In addition, the metallocene compound (A) of Formulas 2 to 6 may include a compound form substituted by hydrogenation, and a metallocene compound represented by Formulas 2 to 6 or a metal substituted by hydrogenation. It may be at least one selected from the group consisting of strong compounds.

Non-limiting examples of the metallocene compound (A) include Me2Si(nPropyl-Cp)(OctahydroFlu)ZrCl2, Me2Si(iPropyl-Cp)(OctahydroFlu)ZrCl2, Me2Si(nHexyl-Cp)(OctahydroFlu)ZrCl2, Me2Si( nOctyl-Cp)(OctahydroFlu)ZrCl2, Me2Si(nDecyl-Cp)(OctahydroFlu)ZrCl2, Me2Si(TetrahydroInd)2ZrCl2-, Me2Si(Me-TetrahydroInd)2ZrCl2, Me2Si2ZrCl2ZrCl2, Me2Si(Et-IndetrahydroInd)(Et-IndetrahydroInd) , Me2Si(Et-Ind)2ZrCl2, CH2CH2(TetrahydroInd)2ZrCl2, CH2CH2(Me-TetrahydroInd)2ZrCl2, CH2CH2(Et-TetrahydroInd)2ZrCl2, etc. can be illustrated.

Activator Compound (B)

The activator compound (B) is a compound that reacts with the metallocene compound (A) to form an ionic compound, and a boron compound or the like may be used. Specific examples of the activator compound (B) include triethylammonium tetraphenyl borate, tributyl ammonium tetraphenyl borate, trimethyl ammonium tetraphenyl borate, tripropyl ammonium tetraphenyl borate, and trimethyl ammonium tetra (p). -Tolyl) borate, tripropylammonium tetra(p-tolyl) borate, triethylammonium tetra(o,p-dimethylphenyl) borate, trimethylammonium tetra(o,p-dimethylphenyl) borate, tributylammonium Tetra (p-trifluoromethylphenyl) borate, trimethylammonium tetra (p-trifluoromethylphenyl) borate, tributylammonium tetrapentafluorophenyl borate, N,N-diethylanilinium tetraphenylborate, N, N-diethylanilinium tetraphenylborate, N,N-dimethylaniliniumtetrapentafluorophenylborate, N,N-diethylaniliniumtetrapentafluorophenylborate, diethylammoniumtetrapentafluorophenylborate, Triphenylphosphonium tetraphenylborate, trimethylphosphonium tetraphenylborate, triphenylcarbonium tetraphenylborate, triphenylcarboniumtetra(p-trifluoromethylphenyl)borate, triphenylcarboniumtetrapentafluorophenyl At least one member may be selected from the group consisting of borates and compounds thereof.

Coactivator Compound (C)

The auxiliary activator compound (C) is an organoaluminum compound, and serves to assist the activation of the catalyst. Specific examples of the auxiliary activator compound (C) include trialkyl aluminum such as trimethylaluminum, triethylaluminum, triisopropylaluminum, dimethylethylaluminum, triisobutylaluminum, trihexylaluminum, and trioctylaluminum; Alkyl aluminum halides, such as dimethyl aluminum chloride, diethyl aluminum chloride, methyl aluminum dichloride, ethyl aluminum dichloride, dimethyl aluminum fluoride, diisobutyl aluminum hydride, diethyl aluminum hydride, and ethyl aluminum sesquichloride; or in combination with an alumoxane co-active agent such as dimethylaluminum or methylalumoxane. The auxiliary activator compound (C) may be used alone or in combination of two or more.

Component Content of Olefin Polymerization Catalyst Composition

In the olefin polymerization catalyst composition according to the present invention, the metallocene compound (A) and the activator compound (B) are mixed in a molar ratio of 10:1 to 1:100, more preferably 2:1 to 1:10. can be used

Further, when the auxiliary activator compound (C) is used, the molar ratio of the metallocene compound (A) to the auxiliary activator compound (C) is preferably 1:1 to 1:10,000, more preferably 1:5 to 1 : can be 1,000. When the molar ratio of the metallocene compound (A) and the auxiliary activator compound (C) is less than 1:1, the amount of the auxiliary activator compound is small, so that the alkylation of the catalyst compound does not proceed completely, and 1: If it exceeds 10,000, it is not preferable because a problem occurs that activation is not completely achieved due to a side reaction between the compounds.

Since the alpha olefin monomer used in the present invention is sensitive to moisture, it is important to manage the moisture contained therein for reasons such as catalyst poison, and the auxiliary activator compound for a scavenger to reduce the effect of moisture in polymerization (C) is used. The use ratio of water and auxiliary activator compound (C) is in the range of 1:1 to 1:1,000, more preferably 1:1 to 1:100.

In the present invention, as a reaction solvent when preparing the olefin polymerization catalyst, hydrocarbon solvents such as pentane, hexane, and heptane or aromatic solvents such as benzene, toluene, and xylene may be used, but the present invention is not limited thereto, and is used when preparing the olefin polymerization catalyst All possible solvents can be used.

Preparation of alpha olefin oligomer first reactant

In order to prepare the alpha olefin oligomer according to the present invention, in the presence of an olefin polymerization catalyst composition, an aliphatic alpha olefin monomer having 3 to 20 carbon atoms, preferably 6 to 14 carbon atoms, is polymerized to form a branched chain branch having 6 to 40 carbon atoms. A first reactant of the alpha olefin oligomer with minimal production is prepared first.

The alpha olefin monomer is specifically, 1-hexene, 4-methyl-1-pentene, 3-methyl-1-pentene, 1-heptene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, etc. can be given as an example, and 1-decene is preferably used. In addition, one of the above monomers may be used alone, or two or more may be used in combination. This includes forms containing isomers.

When preparing the alpha olefin olefin oligomer, as a reaction solvent or diluent, hydrocarbon-based or unsaturated hydrocarbon-based compounds that do not react with the olefin polymerization catalyst composition such as pentane, hexane, and heptane, or aromatic compounds such as benzene, toluene, and xylene may be used, The present invention is not limited thereto, and any solvent or diluent that can be used for olefin polymerization may be used.

The content of the alpha-olefin monomer is 50 to 99 mol%, preferably 70 to 99 mol%, and the olefin polymerization catalyst composition is 0.0001 to 1 mol%, preferably 0.0001 to 0.1 mol%. In addition, the content of the olefin polymerization solvent or diluent is 0 to 50 mol%, preferably 0 to 30 mol%. When there are too many said olefin polymerization solvents or diluents, there exists a problem that polymerization activity falls. When the amount of the alpha-olefin monomer is too small, there is a problem in that a small amount of a target polymerization product is generated or polymerization activity is lowered. In addition, when the amount of the olefin polymerization catalyst composition is too small, there is a problem that polymerization activity is lowered. There is a quality problem.

The molar ratio of the metallocene catalyst used is 1:1,000 to 1:1,000,000, more preferably 1:5,000 to 1:1,000,000, relative to the alpha olefin monomer.

In the preparation of the first reactant of the alpha olefin oligomer, the alpha olefin oligomerization is performed in the presence of an inert gas such as argon or nitrogen, wherein the reaction temperature is 15 to 200 ° C, preferably 50 to 120 ° C, and the polymerization pressure is atmospheric pressure to 2.0 MPa The reaction may proceed under the conditions of, and the reaction time is 10 minutes to 48 hours.

The first reactant of the alpha olefin oligomer includes a long chain branch having 6 to 40 carbon atoms, preferably 16 to 28 carbon atoms, and branched branching generated from the polymerization termination mechanism of the long chain extra-branched metallocene catalyst derived from the alpha olefin chain. exists

The branched branch may be present at the end of the structure of the primary reactant of the alpha olefin oligomer as a short-chain branch, and specifically, an alkylene group having 1 to 3 carbon atoms, for example, a substituted or unsubstituted vinylidene or vinyl group.

An alpha olefin oligomer primary reactant having an average SCB of 80 to 120, preferably 90 to 110 at a number average molecular weight of 1,100 or less of the primary reactant of the alpha olefin oligomer including the branched branch may be prepared.

The weight average molecular weight (Mw) of the primary reactant of the alpha olefin oligomer including the branched branch is 1,500 or less, preferably 400 to 1,100 by gel permeation chromatography using polystyrene as a calibration material.

The first reactant of the alpha olefin oligomer is a post-treatment process, typically, after the type of reaction, the metallocene compound is inactivated using an aqueous solution of a strong base, and all or part of the first reactant of the alpha olefin oligomer from which the monomer is removed. , but the alpha olefin oligomer can be prepared in stages, but the present invention is not limited thereto, and the alpha olefin oligomer is continuously prepared without inactivating the metallocene compound included in all or part of the first reactant of the alpha olefin oligomer. can be manufactured.

In the present invention, the alpha olefin oligomer intermediate may mean a trimer or less of an alpha olefin in the first reactant of the alpha olefin oligomer or a dimer. That is, the first reactant of the alpha olefin oligomer contains all or part of a trimer or less or a dimer (intermediate), and specifically, with respect to the first reactant of the alpha olefin oligomer, a trimer or less or a dimer (intermediate) is 10 to 100% by weight.

A part of the first reactant of the alpha olefin oligomer refers to a trimer or less or a dimer (intermediate) separated from the alpha olefin oligomer from which the monomer is removed. Specifically, the content of the trimer or less or dimer (intermediate) is 50 to 100% by weight, preferably 80 to 100% by weight.

Specifically, after the monomer is removed by distilling the first reactant of the alpha olefin oligomer under reduced pressure, the following reaction may be performed using the entire first reactant as an alpha olefin oligomer intermediate, and the alpha olefin oligomer intermediate (a trimer or less or a dimer) is When included as a part of the first reactant, the next reaction may be carried out by separating the alpha olefin oligomer intermediate of the trimer or less or the dimer. In the first reactant, as a method for isolating the trimer or lower or dimer alpha olefin oligomer intermediate, for example, single distillation or multi-stage distillation through vacuum distillation may be used.

Accordingly, the alpha olefin oligomer can be prepared step by step with the isolated trimer or lower or dimer alpha olefin oligomer intermediate.

Alpha Olefin Oligomer Preparation

The alpha olefin oligomer intermediate (the whole of the primary reactant; or a trimer or less or a part of the primary reactant from which the dimer is separated;) is copolymerized with an alpha olefin monomer having 3 to 20 carbon atoms in the presence of an acid catalyst to obtain trimers and tetramers An alpha olefin oligomer comprising a sieve can be prepared.

The prepared alpha olefin oligomer intermediate can be used by separating the trimer or less, preferably the dimer or less, and more preferably the dimer oligomer. That is, the isolated alpha-olefin oligomer intermediate contains 50 to 100% by weight, preferably 80 to 100% by weight of the dimer. The trimer or less may include, for example, a trimer, a dimer, a dimer including a part of the trimer, or a residual monomer, and the dimer or less may include, for example, a dimer and a residual monomer. .

The alpha olefin monomer includes an aliphatic olefin having 3 to 20 carbon atoms, and specifically, 1-hexene, 4-methyl-1-pentene, 3-methyl-1-pentene, 1-heptene, 1-octene, and 1-decene. , 1-dodecene, 1-tetradecene, etc. may be mentioned as examples, and 1-decene is preferably used. In addition, one of the above monomers may be used alone, or two or more may be used in combination. This includes forms containing isomers.

The acid catalyst is a Friedel-Crafts catalyst, which includes commonly used metal halides and metalloid halides, and may be selected from the group consisting of alone or one or more protic promoters, one or more aprotic promoters, or a combination thereof. The protic promoter may be selected from water, alcohol, acid, or a combination thereof, and the aprotic promoter may be selected from an aldehyde, an anhydride, a ketone, an organic ester, an ether, or a combination thereof. In addition, the solid acid catalyst may be selected from the group consisting of zeolite or zeolite molecular sieve, acid clay mineral, polymer acid resin, ion exchange resin, amorphous solid catalyst, or a combination thereof, preferably boron trifluoride.

In a specific example of the method for preparing an alpha olefin oligomer, which is the secondary reaction of the present invention, a protic promoter selected from boron trifluoride and an alcohol having 1 to 20 carbon atoms is used. The protic promoter acts as a secondary reaction catalyst by forming a complex with boron trifluoride.

The boron trifluoride catalyst is circulated and reused after completion of the reaction, or the non-circulated catalyst is inactivated with water or alcohol.

In the preparation of the alpha olefin oligomer, the alpha olefin oligomerization is performed in the presence of an inert gas such as argon or nitrogen, wherein the reaction temperature is -20 to 100° C., preferably 0 to 60° C., and the polymerization pressure is atmospheric pressure to 1.0 MPa. The reaction can be carried out in a reaction time of 10 minutes to 12 hours.

In the alpha-olefin oligomer, the content of the alpha-olefin monomer is 30 to 70 mol%, preferably 40 to 60 mol%, and when the alpha-olefin monomer is too small, there is a problem in that the content of the trimer is reduced , when too many, there is a problem in that the content of short-chain branches causing deterioration of physical properties increases.

The content of the acid catalyst is 1 to 10 mol%, preferably 2 to 5 mol%, and when the acid catalyst is too small, there is a problem that the activity is lowered, and when too much, there is a problem that the content of the trimer is reduced there is.

The mass ratio of the first reactant of the alpha olefin oligomer (or a part of the first reactant) and the alpha olefin monomer is 1:1 or more, preferably 1:1 to 5:1, and more preferably the result of the following formula 2 1 to 5, more preferably 2 to 4.

[Equation 2]

In Equation 2, the first oligomer product refers to an alpha olefin oligomer primary reactant, that is, all or part of the alpha olefin oligomer primary reactant refers to an alpha olefin oligomer intermediate.

In the polymerization reaction of the alpha olefin oligomer intermediate and the alpha olefin oligomer of the present invention, liquid phase, slurry phase, bulk phase, or gas phase polymerization may be performed alone or in a hydrocarbon solvent. The solvent is specifically an aliphatic hydrocarbon solvent having 5 to 20 carbon atoms, for example, a solvent of pentane, hexane, heptane, nonane, decane and the like and an isomer structure thereof and an aromatic hydrocarbon solvent such as toluene, benzene, and xylene; A hydrocarbon solvent containing a halogen atom such as chlorobenzene may be included, and one type or a combination of two or more types of the hydrocarbon-based solvent may be injected and reacted in a mixed form. The polymerization reaction step may be carried out in a batch, semi-continuous or continuous reaction in a single or combined reactor such as a batch reactor, a flow-through reactor, a semi-batch reactor, and a loop reactor.

The alpha olefin oligomer according to the present invention reacts with an alpha olefin oligomer intermediate in which short-chain branching is suppressed, and as a result, short-chain branching is suppressed, and trimers and tetramers can be obtained in high yield.

After preparing the alpha olefin oligomer, an unreacted alpha olefin monomer, an isomer of an alpha olefin monomer as a side reaction product, and a dimer formed by combining the alpha olefin monomer are removed. The unreacted alpha olefin monomer and side reaction product may be removed by distillation under reduced pressure at a pressure of 0.45 torr and a temperature of 120 to 180°C.

A nickel (Ni) or cobalt (Co)-based catalyst; Alternatively, by hydrogenation in the presence of a noble metal catalyst including palladium (Pd) or platinum (Pt), the double bond of the alpha olefin oligomer may be converted to a saturated state.

In the alpha olefin oligomer, double bonds remain in the oligomerization process, and these double bonds act as a disadvantage when used as lubricating oil or engine oil. In general, a hydrotreating process is performed to convert the alpha olefin oligomer into a saturated state.

The oligomer of the alpha olefin according to the present invention includes trimers and tetramers, and specifically, the content of trimers and tetramers is 70% by weight or more, preferably 85% by weight or more, and more preferably 90% by weight or more.

The average weight molecular weight (Mw) of the alpha olefin oligomer is 1,250 or less, preferably 1,000 or less, more preferably 600 to 900 by gel permeation chromatography using polystyrene as a calibration material, and number average molecular weight (Mn) It is 1,100 or less, Preferably it is 1,000 or less, More preferably, it is 550-800, It is preferable that molecular weight distribution (Mw/Mn) is 1.0-3.0.

The alpha olefin oligomer prepared in the present invention provides an alpha olefin oligomer having a low OBI (Oligomer Braching Index) with a uniform molecular structure and a low methyl group content as a short-chain branch in Equation 1 below.

Specifically, the alpha olefin oligomer of the present invention has an OBI value of 43 or less according to Formula 1, and more specifically, a value of 40 or less.

[Equation 1]

In Equation 1, logM _n means the log value of Number-Average Molecular Weight (M _n ), and the average SCB (Short Chain Branch) is Fourier Transform IR (Fourier Transform IR; FT) -IR) is the intensity ratio (I _CH3 /I _CH2 ) of the CH ₃ peak and the CH ₂ peak from the spectrum, which means the content of a methyl group (-CH ₃ ) bonded as a side branch to the main chain. The logM _n and mean SCB were measured by GPC-IR.

Specifically, in the alpha olefin oligomer according to the present invention, the measured average short chain branching (SCB) is 120 or less, more preferably 115 or less.

The kinematic viscosity at 100° C. of the alpha olefin oligomer of the present invention is 3.5 cSt to 4.4 cSt, preferably 3.8 to 4.2 cSt, and more preferably about 4 cSt.

In addition, the alpha olefin oligomer has a viscosity index of 120 or more, preferably 125 or more, and the Noack evaporation amount is less than 12% by weight.

The alpha olefin oligomer according to the present invention has a more uniform molecular structure than the alpha olefin oligomer polymerized using an acid catalyst, and has a relatively low content of short chain branches, and thus has thermal stability, oxidation stability, long service life, low volatility and high viscosity index.

The alpha olefin oligomer is a base oil for lubricating oil, and is mixed with a fluid selected from the group consisting of mineral oil, dispersant, antioxidant, antiwear agent, defoaming agent, corrosion inhibitor, detergent, seal swelling agent, viscosity improver, and combinations thereof to form a lubricating oil composition. can be provided.

Hereinafter, preferred embodiments of the present invention will be described in detail. However, the present invention is not limited to the embodiments described herein and may be embodied in other forms. Rather, it is provided to fully convey the spirit of the present invention to those skilled in the art so that this disclosure will be thorough and complete.

[Example 1] Preparation of alpha olefin oligomer

1. Preparation of oligomer primary reactant using metallocene catalyst

After adding 392 g of decene to a 1 L stainless steel autoclave reactor substituted with nitrogen, it is maintained at 90° C., and 1 mmol of triisobutylaluminum is added as a scavenger, or if it is not necessary, do not put it. A previously prepared catalyst solution (dimethylsilylenebistetrahydromethylindenylzirconium dichloride 0.028mmol, N,N-dimethylaniliniumtetrapentafluorophenylborate 0.034mmol, triisobutylaluminum 2mmol and toluene 2.5ml) was added, and polymerization was carried out for 3 hours while stirring at 700 rpm. The polymer was added to 500 ml of a previously prepared 1M aqueous sodium hydroxide solution to terminate the reaction. Next, the upper organic layer was extracted, and unreacted decene and the decene isomer as a side reaction product were removed by distillation under reduced pressure to prepare a decene oligomer.

2. Dimer separation of oligomers

After 1500 ml of the decene oligomer prepared above was added to a 2L flask containing a 5-30 cm Viglux distillation column, it was maintained in a vacuum state to remove oxygen. After distillation under reduced pressure at a pressure of 0.45 torr and a temperature range of 120 to 160 ℃, the residue was cooled to room temperature in a vacuum state to prevent thermal decomposition. The unsaturated end group of the separated decene dimer was measured using H-NMR, and the mass % of the olefin composition of the dimer is shown in Table 1.

3. Preparation of alpha olefin oligomer using acid catalyst

In a 100 ml glass flask substituted with nitrogen, 37 mmol of a dimer, 37 mmol of decene, and 1.3 mmol of butanol, which were polymerized and separated using the metallocene catalyst, were added, and then maintained at 30°C. 1 Bar of boron trifluoride gas was introduced at a gauge pressure, and then the polymerization was carried out by stirring for 2 hours. The reaction was terminated by adding 10 ml of ethyl alcohol to the polymer, and the composition of the polymer was measured using GC-FID, and is shown in Table 2 below. Next, the upper organic layer was extracted, and unreacted decene and decene isomers and dimers, which were side reaction products, were removed to prepare decene oligomers.

4. Hydrogenation of oligomers

In a 100 ml stainless steel autoclave reactor, 14 g of 5 wt% palladium/alumina was charged, and the decene oligomer separated above was added, followed by purging with nitrogen at 120° C. for 30 minutes. Thereafter, the temperature was raised to 180° C. to initiate the reaction under a hydrogen pressure of 2 MPa, and the reaction was terminated after 4 hours. The viscosity, viscosity index, Noack, molecular weight and molecular weight distribution, average short chain branching (SCB) distribution, and OBI (Oligomer Branching Index) results of the above experiments are shown in Tables 3 and 4 below.

[Example 2] Preparation of alpha olefin oligomer

1. Preparation of oligomer primary reactant using metallocene catalyst

It proceeded in the same manner as in Preparation Example 1.

2. Dimer separation of oligomers

It proceeded in the same manner as in Preparation Example 1.

3. Preparation of alpha olefin oligomer using acid catalyst

In a 100 ml glass flask substituted with nitrogen, 37 mmol of a dimer, 37 mmol of decene, and 2.1 mmol of butanol, which were polymerized and separated using the metallocene catalyst, were added and maintained at 30°C. 1 Bar of boron trifluoride gas was introduced at a gauge pressure, and then the polymerization was carried out by stirring for 2 hours. The reaction was terminated by adding 10 ml of ethyl alcohol to the polymer, and the composition of the polymer was measured using GC-FID and is shown in Table 2 below. Next, the upper organic layer was extracted, and unreacted decene and decene isomers and dimers, which were side reaction products, were removed to prepare decene oligomers. The viscosity, viscosity index, Noack, molecular weight and molecular weight distribution, average short chain branching (SCB) distribution, and OBI (Oligomer Branching Index) results of the above experiments are shown in Tables 3 and 4 below.

4. Hydrogenation of oligomers

It proceeded in the same manner as in Preparation Example 1.

[Example 3] Preparation of alpha olefin oligomer

1. Preparation of oligomer primary reactant using metallocene catalyst

It proceeded in the same manner as in Preparation Example 1.

2. Dimer separation of oligomers

It proceeded in the same manner as in Preparation Example 1.

3. Preparation of alpha olefin oligomer using acid catalyst

In a 100 ml glass flask substituted with nitrogen, 29 mmol of a dimer, 44 mmol of decene, and 1.3 mmol of butanol, which were polymerized and separated using the metallocene catalyst, were added, and then maintained at 30°C. 1 Bar of boron trifluoride gas was introduced at a gauge pressure, and then the polymerization was carried out by stirring for 2 hours. The reaction was terminated by adding 10 ml of ethyl alcohol to the polymer, and the composition of the polymer was measured using GC-FID and is shown in Table 2 below. Next, the upper organic layer was extracted, and unreacted decene and decene isomers and dimers, which were side reaction products, were removed to prepare decene oligomers. The viscosity, viscosity index, Noack, molecular weight and molecular weight distribution, average short chain branching (SCB) distribution, and OBI (Oligomer Branching Index) results of the above experiments are shown in Tables 3 and 4 below.

4. Hydrogenation of oligomers

It proceeded in the same manner as in Preparation Example 1.

[Example 4] Preparation of alpha olefin oligomer

1. Preparation of oligomer primary reactant using metallocene catalyst

It proceeded in the same manner as in Preparation Example 1.

2. Dimer separation of oligomers

It proceeded in the same manner as in Preparation Example 1.

3. Preparation of alpha olefin oligomer using acid catalyst

In a 100 ml glass flask substituted with nitrogen, 44 mmol of a dimer, 30 mmol of decene, and 1.4 mmol of butanol, which were polymerized and separated using the metallocene catalyst, were added, and then maintained at 30°C. 1 Bar of boron trifluoride gas was introduced at a gauge pressure, and then the polymerization was carried out by stirring for 2 hours. The reaction was terminated by adding 10 ml of ethyl alcohol to the polymer, and the composition of the polymer was measured using GC-FID and is shown in Table 2 below. Next, the upper organic layer was extracted, and unreacted decene and decene isomers and dimers, which were side reaction products, were removed to prepare decene oligomers. The viscosity, viscosity index, Noack, molecular weight and molecular weight distribution, average short chain branching (SCB) distribution, and OBI (Oligomer Branching Index) results of the above experiments are shown in Tables 3 and 4 below.

4. Hydrogenation of oligomers

It proceeded in the same manner as in Preparation Example 1.

[Comparative Example 1] Preparation of alpha olefin oligomer

1. Preparation of alpha-olefin oligomer using acid catalyst

In a 100 ml glass flask substituted with nitrogen, 118 mmol of decene and 1.5 mmol of butanol are added, and then maintained at 30°C. 1 Bar of boron trifluoride gas was introduced at a gauge pressure, and then the polymerization was carried out by stirring for 2 hours. The reaction was terminated by adding 10 ml of ethyl alcohol to the polymer, and the reaction was terminated by adding 10 ml of ethyl alcohol to the polymer. The composition of the polymer was measured using GC-FID, and is shown in Table 2 below. Next, the upper organic layer was extracted, and unreacted decene and decene isomers and dimers as side-reacted products were removed to prepare decene oligomers. The viscosity, viscosity index, Noack, molecular weight and molecular weight distribution, average short chain branching (SCB) distribution, and OBI (Oligomer Branching Index) results of the above experiments are shown in Tables 3 and 4 below.

2. Hydrogenation of oligomers

It proceeded in the same manner as in Preparation Example 1.

[Comparative Example 2] Preparation of alpha olefin oligomer

1. Preparation of oligomer primary reactant using metallocene catalyst

It proceeded in the same manner as in Preparation Example 1.

2. Dimer separation of oligomers

It proceeded in the same manner as in Preparation Example 1.

3. Preparation of alpha olefin oligomer using acid catalyst

In a 100 ml glass flask substituted with nitrogen, 5.3 mmol of a dimer, 107 mmol of decene, and 1.4 mmol of butanol, which was polymerized and separated using the metallocene catalyst, were added and maintained at 30°C. 1 Bar of boron trifluoride gas was introduced at a gauge pressure, and then the polymerization was carried out by stirring for 2 hours. The reaction was terminated by adding 10 ml of ethyl alcohol to the polymer, and the composition of the polymer was measured using GC-FID and is shown in Table 2 below. Next, the upper organic layer was extracted, and unreacted decene and decene isomers and dimers, which were side reaction products, were removed to prepare decene oligomers. The viscosity, viscosity index, Noack, molecular weight and molecular weight distribution, average short chain branching (SCB) distribution, and OBI (Oligomer Branching Index) results of the above experiments are shown in Tables 3 and 4 below.

4. Hydrogenation of oligomers

It proceeded in the same manner as in Preparation Example 1.

[Comparative Example 3] 1. Preparation of a primary reactant using a metallocene catalyst

It proceeded in the same manner as in Preparation Example 1.

2. Dimer separation of oligomers

It proceeded in the same manner as in Preparation Example 1.

3. Preparation of alpha olefin oligomer using acid catalyst

In a 100 ml glass flask substituted with nitrogen, 11 mmol of a dimer, 96 mmol of decene, and 1.4 mmol of butanol, which were polymerized and separated using the metallocene catalyst, were added, and then maintained at 30°C. 1 Bar of boron trifluoride gas was introduced at a gauge pressure, and then the polymerization was carried out by stirring for 2 hours. The reaction was terminated by adding 10 ml of ethyl alcohol to the polymer, and the composition of the polymer was measured using GC-FID and is shown in Table 2 below. Next, the upper organic layer was extracted, and unreacted decene and decene isomers and dimers, which were side reaction products, were removed to prepare decene oligomers. The viscosity, viscosity index, Noack, molecular weight and molecular weight distribution, average short chain branching (SCB) distribution, and OBI (Oligomer Branching Index) results of the above experiments are shown in Tables 3 and 4 below.

4. Hydrogenation of oligomers

It proceeded in the same manner as in Preparation Example 1.

[Evaluation of physical properties]

The physical properties of the alpha olefin oligomers prepared in Examples 1 to 4 and Comparative Examples 1 to 3 were measured as follows.

Analysis of double bond end groups of primary oligomer intermediates using metallocene catalysts

13C NMR was measured at room temperature using Bruker's AVANCE Ⅲ 500MHz Nuclear Magnetic Resonance Spectrometer equipped with a BBO probe, and all spectra were processed using Topspin 2.1 (NMR program provided by Bruker). visualized.

Specifically, Bruker's ZG30 pulse program was used as the pulse program. In the pulse program, the relaxation delay time was 5 seconds, the inductive free decay collection time was 2 seconds, and the S/N (signal to nosie) value was 1,000 or more. measured. In the measured H-NMR spectrum, the integrated intensity of each olefin region was measured using chloroform (7.24 ppm) as a reference material, and the number of hydrogen species in each olefin structure was divided. The mass % of the double bond end group is shown in Table 1 below by dividing the sum of the calculated values from the calculated values of the integrated strength of each olefin.

Unsaturated end group olefins chemical migration domain
(ppm) number of hydrogens in the olefin % by mass of olefin Vinylidene 4.5 - 4.85 2 72.3 Vinyl 4.85 - 5.05 2 5.8 Trisubstituted
Vinylene 5.05 - 5.2 One 18.1 Disubstituted
Vinylene 5.2 - 5.5 2 3.8

Composition analysis of alpha-olefin oligomers

Gas chromatography (GC-FID) analysis equipped with a FID detector (Flame Ionization Detector; FID Detector) is measured as follows. The model is Agilent's 7890A, and DB-5HT (15 m x 250 μm x 0.1 μm) is used as the separation column. Inject 1 μl sample into the column at 300 °C through the inlet. The column flow rate was 1 ml per minute, and the oven temperature was maintained at 35 °C for 2 minutes, then raised to 250 °C at a rate of 10 °C per minute and to 350 °C at a rate of 20 °C per minute, followed by holding for 20 minutes. Then, the temperature was raised to 380 °C at a rate of 60 °C per minute and maintained for 10 minutes. The temperature of the FID detector is 320°C. For reliability and consistency of the data, the analysis values were used as they are without additional correction, and the results are shown in Table 2 below.

Viscosity, Viscosity Index, Noack Measurement

Viscosity (ASTM D 445), VI (viscosity index; ASTM D 2270), and Noack (ASTM D 5800) properties of the alpha olefin oligomers prepared in Examples 1 to 4 and Comparative Examples 1 to 3 were measured.

Measurement of mean short chain branching (SCB) distribution

Using gel permeation chromatography (GPC-IR) equipment equipped with an IR detector (Infrared Detector; IR Detector). Gel permeation chromatography equipped with an IR detector (Gel Permeation Chromatography-IR; GPC-IR; Polymer Laboratory Inc. 220 System) analysis was measured as follows. Two Olexis and one Guard were used as separation columns, and the column temperature was maintained at 160°C. Calibration was performed using a standard polystyrene set from Polymer Laboratory Inc. Trichlorobenzene containing 0.0125% by weight of BHT (antioxidant) was used as the eluent, and the sample concentration was prepared at 2.0 mg/mL, and was measured for 22 minutes at an injection amount of 0.5 mL and a pump flow rate of 1.0 mL/min. The average short chain branching distribution is, after receiving a Fourier transform IR (Fourier Transform IR; FT-IR) signal (Signal) at 3,000 to 2,700 cm-1, the CH ₃ peak located at 2,960 cm-1 and the CH located at 2,928 cm-1 It was calculated from the intensity ratio (I2,960/I2,928) of the _two peaks. The results described in Examples and Comparative Examples were measured after replacing the gel permeation chromatography column with a new one.

Oligomer Branching Index (OBI)

OBI (Oligomer Branching Index): The average short-chain branching distribution for determining the OBI value was measured using GPC-IR equipment. In the following formula 1, logMn is the log value of Number-Average Molecular Weight (Mn), and avg.SCB is the average short-chain branching distribution (when alpha-olefin is used as a comonomer in the ethylene polymerization process, it is derived from this It refers to the content of a methyl group (-CH ₃ ) bonded as a side branch attached to the main chain made by

[Equation 1]

Dimer/monomer dosage
ratio
(mass ratio) GC-FID monomer
zone dimer
zone trimer
zone tetramer
zone pentameric anomaly zone Example 1 2.00 0 % 5% 73% 14% 8 % Example 2 2.00 3% 6% 78% 11% 2 % Example 3 1.33 0 % 4 % 70% 19% 7% Example 4 3.00 0 % 8 % 70% 15% 7% Comparative Example 1 0.00 One % 5% 60% 24% 10% Comparative Example 2 0.10 0 % 4 % 57% 27% 11% Comparative Example 3 0.22 One % 5% 58% 26% 9%

With reference to Table 2, secondary cationic polymerization was performed according to the dimer/monomer mass ratio in Examples 1 to 4 and Comparative Examples 2 to 3, and alpha olefin oligomer polymers with a yield of 90% or more were obtained. When the dimer and monomer mass ratio of the reactants carried out in Examples 1 to 4 was 1:1 or more, it was confirmed that the trimer and tetramer of the polymer were prepared in high yield, and in particular, compared to Comparative Examples 1 to 3, the trimer was in a high ratio. It was confirmed that it was manufactured.

Viscosity Noack 100 ℃ 40 ℃ VI wt% Example 1 4.0 16.7 137 10.56 Example 2 3.5 14.2 129 11.98 Example 3 4.1 18.1 135 11.23 Example 4 4.0 17.2 138 10.24 Comparative Example 1 4.6 21.5 134 12.56 Comparative Example 2 4.7 21.9 135 12.11 Comparative Example 3 4.5 20.6 136 12.24

Referring to Tables 2 and 3, in Examples 1 to 4, alpha olefin oligomers having a trimer content of 70% or more were prepared, and thus only the reactants were removed to selectively remove alpha having a viscosity of about 4 cSt at 100 ° C. The preparation of olefin oligomers was possible.

On the other hand, in Comparative Examples 1 to 3, the content of the trimer is not sufficient, and has a range of viscosity higher than about 4 cSt. In general, the viscosity index has a higher value as the viscosity increases. In the case of the alpha olefin oligomers obtained in Examples 1 and 4, although the viscosity is relatively lower than that of the alpha olefin oligomers obtained in Comparative Examples 1 to 3, the high viscosity It can be confirmed that having better physical properties by having the index.

In the case of the alpha olefin oligomer obtained in Example 2, since it has a low viscosity index by having a lower viscosity compared to Comparative Examples 1 to 3, it is not appropriate to compare the alpha olefin oligomer with Comparative Examples having a high viscosity.

In the case of the alpha olefin oligomer obtained in Example 3, it has a similar viscosity index compared to Comparative Examples 1 to 3, but has a lower viscosity compared to Comparative Examples. Therefore, when compared at the same viscosity, the alpha olefin oligomer obtained in Example 3 has a better viscosity index It can be expected to have physical properties.

In addition, in general, in the case of Noack evaporation, the higher the viscosity, the lower the evaporation. In the case of the alpha olefin oligomers obtained in Examples 1 to 4, despite having a lower viscosity compared to Comparative Examples 1 to 3, a low evaporation amount was obtained. By showing it, it can be confirmed that it has better noak properties. In addition, it can be expected that the low evaporation rate of Noak has higher flash point properties compared to Comparative Examples 1 to 3.

Mn Mw/Mn Average SCB Log Mn OBI Example 1 659 1.05 109.53 2.819 38.89 Example 2 637 1.04 108.63 2.804 38.74 Example 3 673 1.06 115.89 2.828 40.98 Example 4 665 1.05 107.6 2.823 38.12 Comparative Example 1 692 1.07 123.81 2.840 43.59 Comparative Example 2 694 1.07 123.73 2.841 43.55 Comparative Example 3 689 1.06 123.59 2.838 43.54

Referring to Table 4, when the dimer and monomer mass ratio of the reactants carried out in Examples 1 to 4 is 1:1 or more, the average short chain branching distribution satisfies 120 or less, and in particular, the dimer to monomer mass ratio is 2 : In the case of Examples 1, 2 and 4 having 1 or more, it was confirmed that they had an average short chain branching distribution of 110 or less. When the mass ratio of the dimer and the monomer of the reactants carried out in Comparative Examples 1 to 3 is less than 1:1, the average short chain branching has a higher value than in Examples 1 to 4.

A high average short-chain branching value adversely affects the viscosity index, evaporation amount, and flash point properties of the synthetic alpha olefin oligomer, which can be confirmed from Table 4 above. In addition, it can be seen that OBI satisfies 43 or less in Examples 1 to 4, and in particular, in Examples 1, 2, and 4, OBI satisfies a value of 40 or less.

Claims (16)

preparing an alpha olefin oligomer intermediate by polymerizing an alpha olefin monomer having 3 to 20 carbon atoms in the presence of an olefin polymerization catalyst composition;
preparing an alpha olefin oligomer by polymerizing the alpha olefin oligomer intermediate with an alpha olefin monomer having 3 to 20 carbon atoms in the presence of an acid catalyst;
after preparing the alpha olefin oligomer, removing a dimer and residual dimer formed by combining unreacted alpha olefin monomer and an isomer of an alpha olefin monomer as a side reaction product and an alpha olefin monomer; and
A nickel (Ni) or cobalt (Co)-based catalyst; or hydrogenating in the presence of a noble metal catalyst comprising palladium (Pd) or platinum (Pt),
The alpha olefin oligomer has an OBI (Oligomer Braching Index) of 43 or less according to Formula 1 below.
[Equation 1]

In Equation 1, logM _n is the log value of Number-Average Molecular Weight (M _n ), and the average SCB is the intensity ratio of the CH ₃ peak and the CH ₂ peak from the FT-IR spectrum ( I _CH3 /I _CH2 ). The method of claim 1, wherein the OBI of the alpha olefin oligomer is 40 or less. The method of claim 1, wherein the average SCB is 120 or less. The method according to claim 1, wherein the unreacted raw material and solvent are removed from the alpha olefin oligomer, and the kinematic viscosity at 100°C is 3.5 to 4.4 cSt. The method of claim 1, wherein the viscosity index of the alpha olefin oligomer is 125 or more. The method of claim 1, wherein the NOACK evaporation of the alpha olefin oligomer is less than 12 wt%. The alpha olefin according to claim 1, wherein the alpha olefin oligomer has an average weight molecular weight (Mw) of 1,250 or less, a number average molecular weight (Mn) of 1,100 or less, and a molecular weight distribution (Mw/Mn) of 1.0 to 3.0. A method for preparing an oligomer. The method of claim 1, wherein the alpha-olefin oligomer intermediate comprises an alkylene group having 1 to 3 carbon atoms at the terminal thereof. The method of claim 1, wherein the mass ratio of the alpha olefin oligomer intermediate and the alpha olefin monomer is 1:1 to 5:1. The method of claim 1, wherein the alpha olefin oligomer intermediate contains 50 to 100 wt% of the dimer. According to claim 1, The alpha olefin oligomer, the sum of the trimer and the tetramer is 70% by weight or more, the alpha olefin oligomer production method. The method of claim 1, wherein the olefin polymerization catalyst composition is selected from the group consisting of metallocene compounds represented by the following Chemical Formulas 1 to 6.
[Formula 1]

[Formula 2]

[Formula 3]

[Formula 4]

In Formulas 1 to 4, M is a transition metal selected from titanium, zirconium or hafnium,
B is an alkylene group having 1 to 20 carbon atoms, an arylene group having 6 to 20 carbon atoms, dialkyl silicon having 1 to 20 carbon atoms, dialkyl germanium having 1 to 20 carbon atoms, an alkylphosphine group having 1 to 20 carbon atoms, or an alkylphosphine group having 1 to 20 carbon atoms. A linking group of an alkylamine group or a form without a linking group,
X ₁ and X ₂ are each independently a halogen atom, an alkyl group having 1 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, an alkynyl group having 2 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, an alkyl group having 7 to 40 carbon atoms an aryl group, an arylalkyl group having 7 to 40 carbon atoms, an alkylamido group having 1 to 20 carbon atoms, an arylamido group having 6 to 20 carbon atoms, an alkylidene group having 1 to 20 carbon atoms, or an alkoxy group having 1 to 20 carbon atoms;
R ₁ to R ₁₀ are each independently hydrogen, an alkyl group having 1 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, an alkylaryl group having 7 to 20 carbon atoms, an arylalkyl group having 7 to 20 carbon atoms , a cycloalkyl group having 5 to 60 carbon atoms, a heterocyclic group having 4 to 20 carbon atoms, an alkynyl group having 1 to 20 carbon atoms, or a hetero group or a silyl group containing an aryl group having 6 to 20 carbon atoms;
[Formula 5]

[Formula 6]

In Formulas 5 and 6, M is a transition metal selected from titanium, zirconium, and hafnium,
B is an alkylene group having 1 to 20 carbon atoms, an arylene group having 6 to 20 carbon atoms, dialkyl silicon having 1 to 20 carbon atoms, dialkyl germanium having 1 to 20 carbon atoms, an alkylphosphine group having 1 to 20 carbon atoms, or an alkylphosphine group having 1 to 20 carbon atoms. In the form of an alkylamine linking group or no linking group,
X ₁ and X ₂ are each independently a halogen atom, an alkyl group having 1 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, an alkynyl group having 2 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, alkylaryl having 7 to 40 carbon atoms group, an arylalkyl group having 7 to 40 carbon atoms, an alkylamido group having 1 to 20 carbon atoms, an arylamido group having 6 to 20 carbon atoms, an alkylidene group having 1 to 20 carbon atoms, or an alkoxy group having 1 to 20 carbon atoms,
R ₁ to R ₁₀ are each independently hydrogen, an alkyl group having 1 to 20 carbon atoms, alkenyl having 2 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, an alkylaryl group having 7 to 20 carbon atoms, an arylalkyl group having 7 to 20 carbon atoms , a cycloalkyl group having 5 to 60 carbon atoms, a heterocyclic group having 4 to 20 carbon atoms, an alkynyl group having 1 to 20 carbon atoms, or a hetero group or a silyl group containing an aryl group having 6 to 20 carbon atoms,
R ₁₁ , R ₁₃ and R ₁₄ are the same hydrogen as each other, and R ₁₂ are each independently hydrogen, an alkyl group having 1 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, and an aryl group having 7 to 20 carbon atoms. A hetero group or silyl containing an alkylaryl group, an arylalkyl group having 7 to 20 carbon atoms, a cycloalkyl group having 5 to 60 carbon atoms, a heterocyclic group having 4 to 20 carbon atoms, an alkynyl group having 1 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms it's gi According to claim 1, wherein the olefin polymerization catalyst composition is triethylammonium tetraphenyl borate, tributyl ammonium tetraphenyl borate, trimethyl ammonium tetraphenyl borate, tripropyl ammonium tetraphenyl borate, trimethyl ammonium tetra (p- Tolyl) borate, tripropylammonium tetra(p-tolyl) borate, triethylammonium tetra(o,p-dimethylphenyl) borate, trimethylammonium tetra(o,p-dimethylphenyl) borate, tributylammonium tetra (p-trifluoromethylphenyl)borate, trimethylammonium tetra(p-trifluoromethylphenyl)borate, tributylammonium tetrapentafluorophenylborate, N,N-diethylaniliniumtetraphenylborate, N,N -Diethylanilinium tetraphenylborate, N,N-dimethylaniliniumtetrapentafluorophenylborate, N,N-diethylaniliniumtetrapentafluorophenylborate, diethylammoniumtetrapentafluorophenylborate, tri Phenylphosphonium tetraphenyl borate, trimethylphosphonium tetraphenyl borate, triphenyl carbonium tetraphenyl borate, triphenyl carbonium tetra (p-trifluoromethylphenyl) borate, triphenyl carbonium tetrapentafluorophenyl borate and at least one activator compound (B) selected from the group consisting of compounds thereof; and
trialkylaluminum selected from the group consisting of trimethylaluminum, triethylaluminum, triisopropylaluminum, dimethylethylaluminum, triisobutylaluminum, trihexylaluminum, trioctylaluminum and mixtures thereof; The group consisting of dimethyl aluminum chloride, diethyl aluminum chloride, methyl aluminum dichloride, ethyl aluminum dichloride, dimethyl aluminum fluoride, diisobutyl aluminum hydride, diethyl aluminum hydride, ethyl aluminum sesquichloride, and mixtures thereof A method for producing an alpha olefin oligomer comprising at least one auxiliary activator compound (C) selected from the group consisting of alkylaluminum halides selected from and mixtures thereof. The method of claim 1, wherein the acid catalyst is boron trifluoride. The method according to claim 1, wherein the alpha olefin oligomer is used as a base oil for lubricating oil. In the alpha olefin oligomer formed by polymerization of an alpha olefin monomer having 3 to 20 carbon atoms, the alpha olefin oligomer has an OBI (Oligomer Braching Index) of 43 or less according to Formula 1 below,
The unreacted raw material and solvent are removed from the alpha olefin oligomer, and the kinematic viscosity at 100 ° C is 3.5 to 4.4 cSt,
an alpha olefin oligomer having an evaporation amount of NOACK of the alpha olefin oligomer of less than 12% by weight; and
A lubricating oil composition comprising a fluid selected from the group consisting of mineral oils, dispersants, antioxidants, antiwear agents, defoamers, corrosion inhibitors, detergents, seal swelling agents, viscosity improvers, and combinations thereof.
[Equation 1]

In Equation 1, logM _n is the log value of Number-Average Molecular Weight (M _n ), and the average SCB is the intensity ratio of the CH ₃ peak and the CH ₂ peak from the FT-IR spectrum ( I _CH3 /I _CH2 ).