U.S. patent application number 16/982662 was filed with the patent office on 2021-02-04 for method for producing wax isomerized oil.
This patent application is currently assigned to ENEOS Corporation. The applicant listed for this patent is ENEOS Corporation. Invention is credited to Fuyuki AIDA, Kazuo TAGAWA, Koshi TAKAHAMA.
Application Number | 20210032550 16/982662 |
Document ID | / |
Family ID | 1000005193288 |
Filed Date | 2021-02-04 |
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United States Patent
Application |
20210032550 |
Kind Code |
A1 |
TAGAWA; Kazuo ; et
al. |
February 4, 2021 |
METHOD FOR PRODUCING WAX ISOMERIZED OIL
Abstract
A method for producing a wax isomerized oil, comprising a step
of providing an ethylene polymer wax, a step of hydrocracking the
ethylene polymer wax by a hydrocracking catalyst to obtain a
cracked product, and a step of isomerization dewaxing the cracked
product by a hydroisomerization catalyst to obtain a wax isomerized
oil.
Inventors: |
TAGAWA; Kazuo; (Tokyo,
JP) ; AIDA; Fuyuki; (Tokyo, JP) ; TAKAHAMA;
Koshi; (Tokyo, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
ENEOS Corporation |
Tokyo |
|
JP |
|
|
Assignee: |
ENEOS Corporation
Tokyo
JP
|
Family ID: |
1000005193288 |
Appl. No.: |
16/982662 |
Filed: |
February 21, 2019 |
PCT Filed: |
February 21, 2019 |
PCT NO: |
PCT/JP2019/006557 |
371 Date: |
September 21, 2020 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C10G 65/12 20130101;
C10M 105/04 20130101; C10G 2300/1022 20130101; C10N 2040/25
20130101; C10G 2300/302 20130101; C10G 2300/308 20130101; C10G
2300/304 20130101; C10M 2203/0206 20130101; C10N 2030/54
20200501 |
International
Class: |
C10G 65/12 20060101
C10G065/12; C10M 105/04 20060101 C10M105/04 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 27, 2018 |
JP |
2018-059580 |
Claims
1. A method for producing a wax isomerized oil, comprising a step
of providing an ethylene polymer wax, a step of hydrocracking the
ethylene polymer wax by a hydrocracking catalyst to obtain a
cracked product, and a step of isomerization dewaxing the cracked
product by a hydroisomerization catalyst to obtain a wax isomerized
oil.
Description
TECHNICAL FIELD
[0001] The present invention relates to a method for producing a
wax isomerized oil.
BACKGROUND ART
[0002] Conventionally, there has been wax isomerized oil in
addition to mineral base oil, as lubricating base oil. As the
examples of wax for a raw material of wax isomerized oil, natural
wax such as petroleum slack wax obtained by solvent dewaxing of
hydrocarbon oil, or synthetic wax such as one produced by Fischer
Tropsch synthesis by use of synthetic gas (FT wax), are included.
There is known, as a method for producing a high-quality
lubricating base oil, for example, a method involving performing
hydrotreatment and dewaxing treatment of a raw material oil derived
from the above-described wax or the like (see, for example, Patent
Literature 1).
CITATION LIST
Patent Literature
[0003] [Patent Literature 1] Japanese Unexamined Patent Publication
No. 2007-510798
SUMMARY OF INVENTION
Technical Problem
[0004] While a lubricating base oil prepared using conventional raw
material wax or the like can satisfy requirements such as an
improvement in fuel economy and a reduction in amount of discharge
to some extent, as described above, it has been found by studies of
the present inventor that even the lubricating base oil still has
room for improvement in terms of a reduction in traction
coefficient.
[0005] An object of the present invention is then to provide a
method for producing a wax isomerized oil having low in traction
coefficient.
Solution to Problem
[0006] The present invention provides a method for producing a wax
isomerized oil, comprising a step of providing an ethylene polymer
wax, a step of hydrocracking the ethylene polymer wax by a
hydrocracking catalyst to obtain a cracked product, and a step of
isomerization dewaxing the cracked product by a hydroisomerization
catalyst to obtain a wax isomerized oil.
Advantageous Effects of the Invention
[0007] According to the present invention, there is provided a
method for producing a wax isomerized oil having low in traction
coefficient.
DESCRIPTION OF EMBODIMENTS
[0008] Hereinafter, modes for carrying out the present invention
will be described.
[0009] A method for producing a wax isomerized oil, according to
the present embodiment, comprises a step of providing an ethylene
polymer wax (first step), a step of hydrocracking the ethylene
polymer wax by a hydrocracking catalyst to obtain a cracked product
(second step), and a step of isomerization dewaxing the cracked
product by a hydroisomerization catalyst to obtain a wax isomerized
oil (third step).
[0010] The present inventor presumes that the reason why a wax
isomerized oil obtained by the production method according to the
present embodiment exhibits a low traction coefficient is because
of specificity of the carbon number distribution.
[0011] That is, first, in the case of a conventional wax isomerized
oil, a raw material wax such as wax obtained by FT synthesis is
usually a mixture of a hydrocarbon compound having an even number
of carbon atoms (hydrocarbon compound having 2n carbon atoms; n
represents an integer of 1 or more. The same applies hereinafter.)
and a hydrocarbon compound having an odd number of carbon atoms
(hydrocarbon compound having 2n+1 carbon atoms), and the ratio of
both such hydrocarbon compounds are almost the same. While such
hydrocarbon compounds can also be each changed in molecular
structure due to cracking and/or isomerization in a wax isomerized
oil obtained by a conventional method for producing a base oil, for
example, the production method described in Patent Literature 1,
there is not any case where the ratio of one of the hydrocarbon
compound having 2n carbon atoms or the hydrocarbon compound having
2n+1 carbon atoms is extremely high as a whole.
[0012] On the contrary, the raw material wax in the present
embodiment is an ethylene polymer wax (namely, a wax as a polymer
of ethylene), and is mostly a hydrocarbon compound having an even
number of carbon atoms (hydrocarbon compound having 2n carbon
atoms). In a case where a wax isomerized oil is prepared by the
method for producing a wax isomerized oil according to the present
embodiment described above, with the ethylene polymer wax as a raw
material wax, isomerization can allow the change in molecular
structure (for example, production of isoparaffin having 2n-1
carbon atom(s) along with isomerization of normal paraffin having
2n carbon atoms) to occur, and thus the resulting wax isomerized
oil exhibits a specific carbon number distribution where the
proportion of one of a hydrocarbon compound having an even number
of carbon atoms or a hydrocarbon compound having an odd number of
carbon atoms is high. The reason why the wax isomerized oil
according to the present embodiment exhibits a low traction
coefficient as compared with a conventional wax isomerized oil
equivalent in viscosity and viscosity index is considered because
of specificity of such a carbon number distribution.
[0013] Isomerization dewaxing, by use of a hydroisomerization
catalyst in dewaxing of a cracked product obtained by
hydrocracking, is here for allowing low-temperature fluidity to be
favorable. While it is considered that, for example, solvent
dewaxing cannot remove any short-chain normal paraffin prepared by
hydrocracking, then the normal paraffin causes deterioration in
low-temperature fluidity. It is considered that isomerization
dewaxing by use of a hydroisomerization catalyst can allow
isomerization of short-chain normal paraffin to progress, to
suppress deterioration in low-temperature fluidity.
[0014] Examples of the ethylene polymer wax provided in the first
step include ethylene oligomer wax obtained by oligomerization of
ethylene. The "oligomer" in the present embodiment here means a
polymer whose number average molecular weight (Mn) is 5000 or less.
The Mn of such an ethylene oligomer is preferably 3000 or less,
more preferably 1000 or less. The lower limit value of the Mn of
the ethylene oligomer is not particularly limited, but is, for
example, preferably 200 or more, more preferably 250 or more,
further preferably 300 or more. The Mw/Mn representing the degree
of molecular weight distribution (dispersibility) is, for example,
preferably 1.0 to 5.0, more preferably 1.1 to 3.0. When the Mn of
the ethylene oligomer is 3000 or less, it is possible to
efficiently obtain a desired base oil without any need for
stringent isomerization conditions such as an increase in reaction
temperature for obtaining a base oil of a targeted viscosity with
the oligomer as a raw material. It is also possible to prevent an
increase in traction coefficient due to excess isomerization. On
the other hand, when the Mn of the ethylene oligomer is 200 or
more, it is possible to efficiently obtain a base oil of a targeted
viscosity.
[0015] The Mn and Mw of the oligomer can be each determined as, for
example, the molecular weight in terms of polystyrene based on the
calibrated with standard polystyrene by use of a GPC apparatus.
[0016] Normal paraffin is usually included in the ethylene polymer
wax used as the raw material wax. The content of normal paraffin in
the ethylene polymer wax is not particularly limited, and is, for
example, preferably 40% by mass or more, more preferably 50% by
mass or more, further preferably 60% by mass or more based on the
total amount of the ethylene polymer wax. The upper limit of the
content of normal paraffin is also not particularly limited, and
is, for example, usually 100% by mass or less, more preferably 90%
by mass or less, further preferably 85% by mass or less.
[0017] The content of the hydrocarbon compound having an even
number of carbon atoms with respect to the constitution of the
hydrocarbon compounds included in the ethylene polymer wax is
preferably 80% by mass or more, more preferably 90% by mass or more
based on the total amount of the ethylene polymer wax. It is
further preferable to include substantially no hydrocarbon compound
having an odd number of carbon atoms, from the viewpoint of being
capable of more effectively reducing the traction coefficient of
the resulting wax isomerized oil.
[0018] The content of the above-described normal paraffin and the
content of the hydrocarbon compound having an even number of carbon
atoms here mean respective values obtained by performing gas
chromatographic analysis under the following conditions with
respect to the ethylene polymer wax, and measuring and calculating
the proportions of the normal paraffin and the hydrocarbon compound
having an even number of carbon atoms in the total amount of the
ethylene polymer wax. A mixed sample of normal paraffin having 5 to
50 carbon atoms is here used as a standard sample in such
measurement, and such each proportion is determined as the total
proportion of the peak area value corresponding to such normal
paraffin or the total proportion of the peak area value
corresponding to the hydrocarbon compound having an even number of
carbon atoms relative to the total peak area value of a
chromatogram. In the case of hydrocarbon compounds having the same
number of carbon atoms, a hydrocarbon compound having the highest
boiling point (the longest distillation time) is here normal
paraffin, and thus a peak present between the peak corresponding to
the distillation time of normal paraffin having n carbon atom(s)
and the peak corresponding to the distillation time of normal
paraffin having n-1 carbon atom(s) in measurement of the
above-described standard sample is defined to correspond to
non-normal paraffin having n carbon atom(s), and normal paraffin
and non-normal paraffin that are the same in the number of carbon
atom(s) are distinguished from each other, in calculation of the
number of carbon atoms.
[0019] (Gas Chromatography Conditions)
[0020] Column: liquid phase non-polar column (length: 25 mm, inner
diameter: 0.3 mm.PHI., thickness of liquid phase: 0.1 .mu.m)
[0021] Temperature program: 50 to 400.degree. C. (rate of
temperature increase: 10.degree. C./min)
[0022] Carrier gas: helium (linear speed: 40 cm/min)
[0023] Split ratio: 90/1
[0024] Injection volume of sample: 0.5 .mu.L (injection volume of
sample diluted with carbon disulfide 20-fold)
[0025] Detector: hydrogen flame ionization detector (FID)
[0026] The method for producing the ethylene polymer wax is not
particularly limited, and the ethylene polymer wax can be obtained
by, for example, polymerizing (oligomerizing) ethylene in the
presence of an ethylene polymerization catalyst. Examples of
specific one aspect include a method involving introducing ethylene
into a reaction apparatus filled with a catalyst. The method for
introducing ethylene into the reaction apparatus is not
particularly limited.
[0027] A solvent may also be used in such a polymerization
reaction. Examples of the solvent include aliphatic
hydrocarbon-based solvents such as butane, pentane, hexane,
heptane, octane, cyclohexane, methylcyclohexane and decalin; and
aromatic hydrocarbon-based solvents such as tetralin, benzene,
toluene and xylene. The catalyst can be dissolved in such a solvent
to perform solution polymerization, slurry polymerization or the
like.
[0028] The reaction temperature in the polymerization reaction is
not particularly limited, and is, for example, preferably
-50.degree. C. to 100.degree. C., more preferably -30.degree. C. to
80.degree. C., further preferably -20.degree. C. to 70.degree. C.,
particularly preferably 0.degree. C. to 50.degree. C., intensely
preferably 5.degree. C. to 30.degree. C., most preferably 5.degree.
C. to 15.degree. C. from the viewpoint of catalyst efficiency. When
the reaction temperature is -50.degree. C. or more, it is possible
to suppress precipitation of a polymer prepared with the catalyst
activity being maintained, and when the reaction temperature is
100.degree. C. or less, it is possible to suppress degradation of
the catalyst. The reaction pressure is also not particularly
limited, but is, for example, preferably 100 kPa to 5 MPa. The
reaction time is also not particularly limited, but is, for
example, preferably 1 minute to 24 hours, more preferably 5 minutes
to 60 minutes, further preferably 10 minutes to 45 minutes,
particularly preferably 20 minutes to 40 minutes.
[0029] The ethylene polymerization catalyst is not particularly
limited, and examples thereof include a catalyst including an iron
compound represented by the following formula (1).
##STR00001##
[0030] In the formula (1), R represents a hydrocarbyl group of 1 to
6 carbon atoms or an aromatic group of 6 to 12 carbon atoms, and a
plurality of R in the same molecule may be the same or different.
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. Y represents a chlorine atom or a bromine
atom.
[0031] Examples of the hydrocarbyl group of 1 to 6 carbon atoms
include an alkyl group of 1 to 6 carbon atoms and an alkenyl group
of 2 to 6 carbon atoms. The hydrocarbyl group may be any of a
linear, branched or cyclic group. Furthermore, the hydrocarbyl
group may be a monovalent group where a linear or branched
hydrocarbyl group and a cyclic hydrocarbyl group are bonded.
[0032] Examples of the alkyl group of 1 to 6 carbon atoms include
linear alkyl groups of 1 to 6 carbon atoms, such as a methyl group,
an ethyl group, a n-propyl group, a n-butyl group, a n-pentyl group
and a n-hexyl group; branched alkyl group of 3 to 6 carbon atoms,
such as an iso-propyl group, an iso-butyl group, a sec-butyl group,
a tert-butyl group, a branched pentyl group (including all
structural isomers) and a branched hexyl group (including all
structural isomers); and cyclic alkyl groups of 1 to 6 carbon
atoms, such as a cyclopropyl group, a cyclobutyl group, a
cyclopentyl group and a cyclohexyl group.
[0033] Examples of the alkenyl group of 2 to 6 carbon atoms include
linear alkenyl groups of 2 to 6 carbon atoms, such as an ethenyl
group (vinyl group), a n-propenyl group, a n-butenyl group, a
n-pentenyl group and a n-hexenyl group; branched alkenyl groups of
2 to 6 carbon atoms, such as an iso-propenyl group, an iso-butenyl
group, a sec-butenyl group, a tert-butenyl group, a branched
pentenyl group (including all structural isomers) and a branched
hexenyl group (including all structural isomers); and cyclic
alkenyl groups of 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.
[0034] Examples of the aromatic group of 6 to 12 carbon atoms
include a phenyl group, a toluyl group, a xylyl group and a
naphthyl group.
[0035] In the formula (1), a plurality of R and a plurality of R'
in the same molecule may be the same or different. But they may be
the same from the viewpoint of simplifying compound synthesis.
[0036] The free radical having an oxygen atom and/or a nitrogen
atom may be a free radical of 0 to 6 carbon atoms, having an oxygen
atom and/or a nitrogen atom, and examples thereof include a methoxy
group, an ethoxy group, an isopropoxy group and a nitro group.
[0037] Specific examples of such an iron compound include compounds
represented by the following formulas (1a) to (1h). Such iron
compounds can be used singly or in combinations of two or more
thereof.
##STR00002## ##STR00003##
[0038] The compound (hereinafter, sometimes also referred to as
"diimine compound") constituting a ligand in the iron compound
represented by formula (1) can be obtained by, for example,
performing condensation between dibenzoylpyridine and an aniline
compound with eliminating water in the presence of an acid.
[0039] A preferable aspect of the method for producing the
above-described diimine compound includes a first step of
dissolving 2,6-dibenzoylpyridine, an aniline compound and an acid
in a solvent and performing dehydration and condensation under
heating and reflux of the solvent, and a second step of performing
a separation/purification treatment of a reaction mixture after the
first step, to obtain a diimine compound.
[0040] It is possible to use, for example, an organoaluminum
compound as the acid used in the first step. Examples of the
organoaluminum compound include trimethyl aluminum, triethyl
aluminum, tripropyl aluminum, triisopropyl aluminum, tributyl
aluminum, triisobutyl aluminum, trihexyl aluminum, trioctyl
aluminum, diethyl aluminum chloride, ethyl aluminum dichloride,
ethyl aluminum sesquichloride and methylaluminoxane.
[0041] It is also possible to use a protonic acid, besides the
above-described organoaluminum compound, as the acid used in the
first step. Such a protonic acid is used as an acid catalyst
donating a proton. The protonic acid used is not particularly
limited, but an organic acid is prefered. Examples of such a
protonic acid are acetic acid, trifluoroacetic acid,
methanesulfonic acid, trifluoromethanesulfonic acid and
p-toluenesulfonic acid. In a case where such a protonic acid is
used, it is preferable to remove water by a Dean-Stark water
separator or the like, from the viewpoint of suppression of
by-production of water. It is also possible to perform a reaction
in the presence of an adsorbent such as molecular sieves. The
amount of the protonic acid to be used is not particularly limited,
but a catalytic amount may be enough.
[0042] Examples of the solvent used in the first step are a
hydrocarbon-based solvent and an alcohol-based solvent. Examples of
the hydrocarbon-based solvent are hexane, heptane, octane, benzene,
toluene, xylene, cyclohexane and methylcyclohexane. Examples of the
alcohol-based solvent are methanol, ethanol and isopropyl
alcohol.
[0043] The reaction conditions in the first step can be
appropriately selected depending on the types and amounts of the
raw material compound, the acid and the solvent.
[0044] The separation/purification treatment in the second step is
not particularly limited, and examples thereof are silica gel
column chromatography and a recrystallization method. Especially,
when the organoaluminum compound described above is used as the
acid, it is preferable to make purification after mixing of a
reaction solution with a basic aqueous solution to decompose and
remove aluminum compound.
[0045] The method for mixing the diimine compound with iron is not
particularly limited, and examples thereof include [0046] (i) a
method involving adding and mixing a salt of iron (hereinafter,
also sometimes simply referred to as "salt") to and with a solution
where the diimine compound is dissolved, and [0047] (ii) a method
involving physically mixing the diimine compound with such a salt
without use of any solvent.
[0048] The method for taking out a complex from a mixture of the
diimine compound with iron is not particularly limited, and
examples thereof include [0049] (a) a method involving distilling
off a solvent, if the solvent is used to prepare the mixture, to
separate a solid by filtration, [0050] (b) a method involving
separating a precipitate generated from the mixture by filtration,
[0051] (c) a method involving adding a poor solvent to the mixture
for purification and separating a precipitate by filtration, and
[0052] (d) a method involving directly taking out a solvent-free
mixture. [0053] Thereafter, the resultant mixture may be washed
with a solvent dissolving the diimine compound, a solvent
dissolving a metal, and a recrystallization with a proper solvent,
and/or the like.
[0054] Examples of the salt of iron are iron(II) chloride,
iron(III) chloride, iron(II) bromide, iron(III) bromide,
acetylacetonate iron(II), acetylacetonate iron(III), iron(II)
acetate and iron(III) acetate. The above-described salts having a
ligand such as a solvent or water may also be used. Among them, a
salt of iron(II) is preferable, and iron(II) chloride is more
preferable.
[0055] The solvent for mixing the diimine compound with iron is not
particularly limited, and any of a non-polar solvent and a polar
solvent can be used. Examples of the non-polar solvent are
hydrocarbon-based solvents such as hexane, heptane, octane,
benzene, toluene, xylene, cyclohexane and methylcyclohexane.
Examples of the polar solvent are polar protonic solvents such as
alcohol and polar aprotic solvents such as tetrahydrofuran.
Examples of the alcohol solvent are methanol, ethanol and isopropyl
alcohol. Especially, when the mixture is used directly as a
catalyst, it is preferable to use a hydrocarbon-based solvent
having substantially no effect on an ethylene polymerization
reaction.
[0056] The mixing ratio between the diimine compound and the iron
compound in contacting both is not particularly limited. The ratio
of diimine compound/iron compound may be 0.2/1 to 5/1, may be 0.3/1
to 3/1, may be 0.5/1 to 2/1, or maybe 1/1, on a molar ratio.
[0057] While it is preferable that two imine moieties in the
diimine compound are both E-forms, a Z-form diimine may be included
as a diimine compound where both imine moieties are E-forms. The
diimine compound including a Z-form hardly forms a complex with a
metal, and thus can be formed into a complex in a system and then
easily removed in a purification step such as solvent washing.
[0058] An ethylene polymerization catalyst including the iron
compound represented by the formula (1) may further contain an
organoaluminum compound in order to allow a polymerization reaction
to more efficiently progress. Examples of the organoaluminum
compound are trimethyl aluminum and methylaluminoxane. The content
ratio between the iron compound represented by formula (1) and the
organoaluminum compound is preferably G:H=1:10 to 1:1000, more
preferably 1:10 to 1:800, further preferably 1:20 to 1:600,
particularly preferably 1:20 to 1:500 on a molar ratio in a case
where the number of moles of the iron compound is designated as G
and the number of moles of an aluminum atom in the organoaluminum
compound is designated as H. When the ratio is in the above range,
it is possible to suppress an increase in cost with a more
sufficient polymerization activity being exhibited.
[0059] In a case where methylaluminoxane is used as the
organoaluminum compound, it is possible to not only use a
commercially available methylaluminoxane product diluted with a
solvent, but also use trimethyl aluminum partially hydrolyzed in a
solvent. It is also possible to use modified methylaluminoxane
obtained by allowing trialkyl aluminum other than trimethyl
aluminum, like triisobutyl aluminum, to coexist in partial
hydrolysis of trimethyl aluminum and performing co-partial
hydrolysis. Furthermore, in a case where unreacted trialkyl
aluminum remains during the above-described partial hydrolysis, the
unreacted trialkyl aluminum may be removed by distillation under
reduced pressure. Modified methylaluminoxane obtained by modifying
methylaluminoxane with an active proton compound such as phenol or
a derivative thereof may also be used.
[0060] In a case where trimethyl aluminum and methylaluminoxane are
used in combination in the organoaluminum compound, the content
ratio between trimethyl aluminum and methylaluminoxane in the
ethylene polymerization catalyst is preferably
H.sub.1:H.sub.2=100:1 to 1:100, more preferably 50:1 to 1:50,
further preferably 10:1 to 1:10 on a molar ratio in a case where
the number of moles of trimethyl aluminum is designated as H.sub.1
and the number of moles of an aluminum atom in methylaluminoxane is
designated as H.sub.2. When the ratio is in the above range, it is
possible to suppress an increase in cost with a more sufficient
catalyst efficiency being exhibited.
[0061] The ethylene polymerization catalyst including the iron
compound represented by the formula (1) may further include a boron
compound as an arbitrary component.
[0062] The boron compound has a function as a co-catalyst that
further enhances the catalyst activity of the iron compound
represented by the formula (1) in the ethylene polymerization
reaction.
[0063] Examples of the boron compound are an aryl boron compound
such as trispentafluorophenyl borane. It is possible to use a boron
compound having anion species, as the boron compound. The examples
are aryl borates such as tetrakispentafluorophenylborate and
tetrakis(3,5-trifluoromethylphenyl)borate. Specific examples of
such aryl borate include lithium tetrakispentafluorophenylborate,
sodium tetrakispentafluorophenylborate, N,N-dimethylanilinium
tetrakispentafluorophenylborate, trityl
tetrakispentafluorophenylborate, lithium
tetrakis(3,5-trifluoromethylphenyl)borate, sodium
tetrakis(3,5-trifluoromethylphenyl)borate, N,N-dimethylanilinium
tetrakis(3,5-trifluoromethylphenyl)borate and trityl
tetrakis(3,5-trifluoromethylphenyl)borate. Among them,
N,N-dimethylanilinium tetrakispentafluorophenylborate, trityl
tetrakispentafluorophenylborate, N,N-dimethylanilinium
tetrakis(3,5-trifluoromethylphenyl)borate or trityl
tetrakis(3,5-trifluoromethylphenyl)borate is preferable. Such boron
compounds can be used singly or in combinations of two or more
thereof.
[0064] In a case where the organoaluminum compound and the boron
compound are used in combination in the ethylene polymerization
catalyst, the content ratio between the organoaluminum compound and
the boron compound is preferably H:J=1000:1 to 1:1, more preferably
800:1 to 2:1, further preferably 600:1 to 10:1 on a molar ratio in
a case where the number of moles of the organoaluminum compound is
designated as H and the number of moles of the boron compound is
designated as J. When the ratio is in the above range, it is
possible to suppress an increase in cost with a more sufficient
catalyst efficiency being exhibited.
[0065] The ethylene polymerization catalyst including the iron
compound represented by the formula (1) may further contain a
compound represented by the following formula (2) (hereinafter,
sometimes also referred to as "ligand") from the viewpoint of
ensuring a more sufficient catalyst efficiency.
##STR00004##
[0066] In the formula (2), R'' represents a hydrocarbyl group of 1
to 6 carbon atoms or an aromatic group of 6 to 12 carbon atoms, a
plurality of R'' in the same molecule may be the same or different,
R''' represents a free radical of 0 to 6 carbon atoms, the radical
having an oxygen atom and/or an nitrogen atom, and a plurality of
R''' in the same molecule may be the same or different.
[0067] Examples of the hydrocarbyl group of 1 to 6 carbon atoms
include an alkyl group of 1 to 6 carbon atoms and an alkenyl group
of 2 to 6 carbon atoms. The hydrocarbyl group may be any of a
linear, branched or cyclic group. Furthermore, the hydrocarbyl
group may be a monovalent group where a linear or branched
hydrocarbyl group and a cyclic hydrocarbyl group are bonded.
[0068] Examples of the alkyl group of 1 to 6 carbon atoms include
linear alkyl groups of 1 to 6 carbon atoms, such as a methyl group,
an ethyl group, a n-propyl group, a n-butyl group, a n-pentyl group
and a n-hexyl group; branched alkyl group of 3 to 6 carbon atoms,
such as an iso-propyl group, an iso-butyl group, a sec-butyl group,
a tert-butyl group, a branched pentyl group (including all
structural isomers) and a branched hexyl group (including all
structural isomers); and cyclic alkyl groups of 1 to 6 carbon
atoms, such as a cyclopropyl group, a cyclobutyl group, a
cyclopentyl group and a cyclohexyl group.
[0069] Examples of the alkenyl group of 2 to 6 carbon atoms include
linear alkenyl groups of 2 to 6 carbon atoms, such as an ethenyl
group (vinyl group), a n-propenyl group, a n-butenyl group, a
n-pentenyl group and a n-hexenyl group; branched alkenyl groups of
2 to 6 carbon atoms, such as an iso-propenyl group, an iso-butenyl
group, a sec-butenyl group, a tert-butenyl group, a branched
pentenyl group (including all structural isomers) and a branched
hexenyl group (including all structural isomers); and cyclic
alkenyl groups of 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.
[0070] Examples of the aromatic group of 6 to 12 carbon atoms
include a phenyl group, a toluyl group, a xylyl group and a
naphthyl group.
[0071] In the formula (2), a plurality of R'' and a plurality of
R''' in the same molecule may be each the same or different. But
they may be each the same from the viewpoint of simplifying
compound synthesis.
[0072] The free radical having an oxygen atom and/or a nitrogen
atom may be a free radical of 0 to 6 carbon atoms, the radical
having an oxygen atom and/or a nitrogen atom, and examples thereof
include a methoxy group, an ethoxy group, an isopropoxy group and a
nitro group.
[0073] Specific examples of such a ligand include compounds
represented by the following formulas (2a) to (2d). Such ligands
can be used singly or in combinations of two or more thereof.
##STR00005##
[0074] R in the formula (1) and R'' in the formula (2), and R' in
the formula (1) and R''' in the formula (2), in the iron compound
represented by the above-described formula (1) and the compound
represented by the above-described formula (2) included in the
ethylene polymerization catalyst in the present embodiment, may be
each the same or different, and are preferably each the same from
the viewpoint of allowing the same performance as in the iron
compound represented by the formula (1) to be maintained.
[0075] In a case where the above-described ligand is included in
the ethylene polymerization catalyst in the present embodiment, the
content ratio between the iron compound and the ligand is not
particularly limited. The ratio of ligand/ iron compound is
preferably 1/100 to 100/1, more preferably 1/20 to 50/1, further
preferably 1/10 to 10/1, particularly preferably 1/5 to 5/1, very
preferably 1/3 to 3/1 on a molar ratio. When the ratio of ligand/
iron compound is 1/100 or more, it is possible to sufficiently
exert the effect of addition of the ligand, and when the ratio is
100/1 or less, it is possible to suppress the cost with the effect
of addition of the ligand being exerted.
[0076] The above-described method for producing the ethylene
polymerization catalyst is not particularly limited, and, in a case
where the ethylene polymerization catalyst includes the iron
compound represented by the formula (1) and the organoaluminum
compound, examples include a method involving adding and mixing a
solution including the organoaluminum compound to and with a
solution including the iron compound represented by the formula (1)
and a method involving adding and mixing a solution including the
iron compound represented by the formula (1) to and with a solution
including the organoaluminum compound. For example, in a case where
the above-described boron compound and the ligand are further
included besides the iron compound represented by the formula (1)
and the organoaluminum compound, all the components may be
contacted collectively or may be contacted in any order. Examples
of the method for producing the ethylene polymerization catalyst in
the present embodiment include [0077] (A) a method involving mixing
a solution including the iron compound represented by the formula
(1) and a solution including the boron compound, and then
contacting the resulting mixture with the organoaluminum compound,
[0078] (B) a method involving mixing a solution including the iron
compound represented by the formula (1) and a solution including
the organoaluminum compound, and then contacting the resulting
mixture with the boron compound, [0079] (C) a method involving
mixing a solution including the boron compound and a solution
including the organoaluminum compound, and then contacting the
resulting mixture with the iron compound represented by the formula
(1), [0080] (D) a method involving mixing a solution including the
iron compound represented by the formula (1) and a solution
including the ligand, and then contacting the resulting mixture
with the organoaluminum compound, [0081] (E) a method involving
mixing a solution including the iron compound represented by the
formula (1) and a solution including the organoaluminum compound,
and then contacting the resulting mixture with the ligand, [0082]
(F) a method involving mixing a solution including the
organoaluminum compound and a solution including the ligand, and
then contacting the resulting mixture with the iron compound
represented by the formula (1), [0083] (G) a method involving
mixing a solution including the iron compound represented by the
formula (1) and a solution including the boron compound, then
adding and mixing a solution including the organoaluminum compound
thereto and therewith, and then contacting the resulting mixture
with the ligand, [0084] (H) a method involving mixing a solution
including the iron compound represented by the formula (1) and a
solution including the boron compound, then adding and mixing a
solution including the ligand thereto and therewith, and then
contacting the resulting mixture with the organoaluminum compound,
[0085] (I) a method involving mixing a solution including the iron
compound represented by the formula (1) and a solution including
the organoaluminum compound, then adding and mixing a solution
including the boron compound thereto and therewith, and then
contacting the resulting mixture with the ligand, [0086] (J) a
method involving mixing a solution including the iron compound
represented by the formula (1) and a solution including the
organoaluminum compound, then adding and mixing a solution
including the ligand thereto and therewith, and then contacting the
resulting mixture with the boron compound, [0087] (K) a method
involving mixing a solution including the iron compound represented
by the formula (1) and a solution including the ligand, then adding
and mixing a solution including the organoaluminum compound thereto
and therewith, and then contacting the resulting mixture with the
boron compound, [0088] (L) a method involving mixing a solution
including the iron compound represented by the formula (1) and a
solution including the ligand, then adding and mixing a solution
including the boron compound thereto and therewith, and then
contacting the resulting mixture with the organoaluminum compound,
[0089] (M) a method involving mixing a solution including the boron
compound and a solution including the organoaluminum compound, then
adding and mixing a solution including the iron compound
represented by the formula (1) thereto and therewith, and then
contacting the resulting mixture with the ligand, [0090] (N) a
method involving mixing a solution including the boron compound and
a solution including the organoaluminum compound, then adding and
mixing a solution including the ligand thereto and therewith, and
then contacting the resulting mixture with the iron compound
represented by the formula (1), [0091] (O) a method involving
mixing a solution including the boron compound and a solution
including the ligand, then adding and mixing a solution including
the iron compound represented by the formula (1) thereto and
therewith, and then contacting the resulting mixture with the
organoaluminum compound, [0092] (P) a method involving mixing a
solution including the boron compound and a solution including the
ligand, then adding and mixing a solution including the
organoaluminum compound thereto and therewith, and then contacting
the resulting mixture with the iron compound represented by the
formula (1), [0093] (Q) a method involving mixing a solution
including the organoaluminum compound and a solution including the
ligand, then adding and mixing a solution including the iron
compound represented by the formula (1) thereto and therewith, and
then contacting the resulting mixture with the boron compound,
[0094] (R) a method involving mixing a solution including the
organoaluminum compound and a solution including the ligand, then
adding and mixing a solution including the boron compound thereto
and therewith, and then contacting the resulting mixture with the
iron compound represented by the formula (1), [0095] (S) a method
involving contacting the boron compound with a solution including
the iron compound represented by the formula (1), and then adding
and mixing a solution including the organoaluminum compound thereto
and therewith, and [0096] (T) a method involving contacting the
boron compound with a solution including the iron compound
represented by the formula (1), then adding and mixing a solution
including trimethyl aluminum thereto and therewith, and then
contacting the resulting mixture with methylaluminoxane.
[0097] It is possible in the second step to hydrocrack the raw
material by a hydrocracking catalyst with the above-described
ethylene polymer wax as a raw material to thereby obtain a cracked
product. Examples of the hydrocracking catalyst are respective
catalysts containing a Group 6 metal, a Group 8 to 10 metal, and a
mixture thereof Examples of a preferable metal are nickel,
tungsten, molybdenum, cobalt, and a mixture thereof. The
hydrocracking catalyst can be used in a mode where the
above-described metal is supported on a heat-resistant metal oxide
carrier, and usually the metal is present as oxide or sulfide, on
the carrier. In a case where such a metal mixture is used, there
may be present as a bulk metal catalyst where the amount of metals
is 30% by mass or more based on the total amount of the catalyst.
Examples of the metal oxide carrier are oxides such as silica,
alumina, silica-alumina or titania, and in particular, alumina is
preferable. Preferable alumina is .gamma. or .beta. porous alumina.
The amount of the metal to be supported is preferably in the range
from 0.5 to 35% by mass based on the total amount of the catalyst.
In a case where a mixture of any of a Group 9 to 10 metal and a
Group 6 metal is used, it is preferable that any Group 9 or 10
metal be present in an amount of 0.1 to 5% by mass and a Group 6
metal be present in an amount of 5 to 30% by mass based on the
total amount of the catalyst. The amount of the metal to be
supported may be measured by atomic absorption spectrometry,
inductively coupled plasma optical emission spectrometry, or other
method prescribed in ASTM with respect to each metal.
[0098] The acidity of the metal oxide carrier can be controlled by
addition of an additional substance, control of properties of the
metal oxide carrier (for example, control of the amount of silica
to be incorporated into a silica-alumina carrier), and/or the like.
Examples of the additional substance are halogen, in particular,
fluorine, phosphorus, boron, yttria, alkali metals, alkaline earth
metals, rare-earth oxide, and magnesia. While a co-catalyst like
halogen generally increases the acidity of the metal oxide carrier,
a weak basic additional substance like yttria or magnesia tends to
decrease the acidity of such a carrier.
[0099] With respect to the hydrocracking treatment conditions, the
treatment temperature is preferably 150 to 450.degree. C., more
preferably 200 to 400.degree. C., the hydrogen partial pressure is
preferably 1400 to 20000 kPa, more preferably 2800 to 14000 kPa,
the liquid hourly space velocity (LHSV) is preferably 0.1 to 10
hr.sup.-1, more preferably 0.1 to 5 hr.sup.-1, and the hydrogen/oil
ratio is preferably 50 to 1780 m.sup.3/m.sup.3, more preferably 89
to 890 m.sup.3/m.sup.3. The above-described conditions are merely
examples, and it is preferable for the hydrocracking treatment
conditions to be appropriately selected depending on the
differences in raw material, catalyst, apparatus, and the like.
[0100] It is possible in the third step a lubricating base oil as a
wax isomerized oil can be obtained by isomerization dewaxing of the
cracked product obtained in the above-described second step The
isomerization dewaxing is to contact the ethylene polymer wax with
a hydroisomerization catalyst in the presence of hydrogen
(molecular hydrogen) and thus dewax a raw material by
hydroisomerization. Examples of such hydroisomerization here also
include conversion of olefins to paraffin by hydrogenation and
conversion of alcohols to paraffin by a dehydrogenation group, in
addition to isomerization of normal paraffin to isoparaffin.
[0101] The hydroisomerization catalyst may include any of
crystalline or amorphous material. Examples of the crystalline
material include a molecular sieve having 10- or 12-membered ring
channels mainly made of aluminosilicate (zeolite) or
silicoaluminophosphate (SAPO). Specific examples of the zeolite
include ZSM-22, ZSM-23, ZSM-35, ZSM-48, ZSM-57, Ferrierite, ITQ-13,
MCM-68 and MCM-71. Examples of the aluminophosphate include ECR-42.
Examples of the molecular sieve are zeolite beta and MCM-68. Among
them, it is preferable to use one or two or more selected from
ZSM-48, ZSM-22 and ZSM-23, and ZSM-48 is particularly preferable.
The molecular sieve is preferably a hydrogen type. Reduction of the
hydroisomerization catalyst can occur on site in the
hydroisomerization, and a hydroisomerization catalyst subjected to
a reductive treatment in advance may be subjected to the
hydroisomerization.
[0102] Examples of the amorphous material of the hydroisomerization
catalyst are alumina doped with a Group 3 metal, fluorinated
alumina, silica-alumina, and fluorinated silica-alumina.
[0103] Examples of a preferable aspect of the hydroisomerization
catalyst are bifunctional one, namely, one where a metal
hydrogenation component being at least one Group 6 metal, at least
one Group 8 to 10 metal, or a mixture thereof is attached. A
preferable metal is a Group 9 or 10 noble metal such as Pt, Pd or a
mixture thereof. The amount of such a metal to be attached is
preferably 0.1 to 30% by mass based on the total amount of the
catalyst. Examples of the methods of catalyst preparation and metal
attachment are an ion-exchange method and an impregnation method
each using a decomposable metal salt, respectively.
[0104] In a case where the molecular sieve is used, a composite
with a binder material having heat resistance under the
hydroisomerization conditions may be formed, or no binder
(self-binding) may be used. Examples of the binder material include
inorganic oxides including two-component combinations with other
metal oxide such as silica, alumina, silica-alumina, silica and
titania, magnesia, thoria, and zirconia, and three-component
combinations of oxides, such as silica-alumina-thoria and
silica-alumina-magnesia. The amount of the molecular sieve in the
hydroisomerization catalyst is preferably 10 to 100% by mass, more
preferably 35 to 100% by mass based on the total amount of the
catalyst. The hydroisomerization catalyst is formed by a method
such as spray-drying or extrusion. The hydroisomerization catalyst
can be used in a sulfide or non-sulfide mode, preferably a sulfide
mode.
[0105] With respect to the hydroisomerization conditions, the
temperature is preferably 250 to 400.degree. C., more preferably
275 to 350.degree. C., the hydrogen partial pressure is preferably
791 to 20786 kPa (100 to 3000 psig), more preferably 1480 to 17339
kPa (200 to 2500 psig), the liquid hourly space velocity is
preferably 0.1 to 10 hr.sup.-1, more preferably 0.1 to 5 hr.sup.-1,
and the hydrogen/oil ratio is preferably 45 to 1780 m.sup.3/m.sup.3
(250 to 10000 scf/B), more preferably 89 to 890 m.sup.3/m.sup.3
(500 to 5000 scf/B). The above conditions are merely examples, and
it is preferable for the hydroisomerization conditions to be
appropriately selected depending on the differences in raw
material, catalyst, and apparatus.
[0106] The production method according to the present embodiment
may include, before subjecting the ethylene polymer wax to the
above-described second step, a step (raw material distillation
step) of fractionally distilling the raw material wax. The fraction
obtained by undergoing the raw material distillation step can be
subjected, as a treated oil, to the second step and the third step,
thereby allowing a wax isomerized oil of an objective viscosity
grade to be efficiently obtained.
[0107] The boiling point range of the fraction in the raw material
distillation step can be appropriately adjusted. The boiling point
range of the fraction can be adjusted to, for example, fractionally
distill a fraction whose boiling point range is 250 to 500.degree.
C. Furthermore, in a case where a wax isomerized oil corresponding
to 70 Pale, SAE-10 or VG6 is obtained, the boiling point range of
each fraction can be as follows, for example.
[0108] 70 Pale: fraction whose boiling point range is 300 to
460.degree. C.
[0109] SAE-10: fraction whose boiling point range is 360 to
500.degree. C.
[0110] VG6: fraction whose boiling point range is 250 to
440.degree. C.
[0111] For example, the boiling point range being 250 to
500.degree. C. indicates that the initial boiling point and the end
point are in the range from 250 to 500.degree. C.
[0112] The distillation conditions in the raw material distillation
step are not particularly limited as long as there are conditions
that enable an objective fraction to be fractionally distilled from
the ethylene polymer wax. For example, the raw material
distillation step may be a step of fractionally distilling by
distillation under reduced pressure, or may be a step of
fractionally distilling with a combination of distillation at
ambient pressure (or distillation under pressure) and distillation
under reduced pressure. For example, a single fraction may be
fractionally distilled or a plurality of fractions depending on the
viscosity grade may be fractionally distilled, from the ethylene
polymer wax in the raw material distillation step.
[0113] A wax isomerized oil where normal paraffin included in the
cracked product is isomerized to isoparaffin in the above-described
third step may be, if desired, subjected to hydrorefining or may be
fractionally distilled to a fraction having a desired viscosity
grade.
[0114] For example, olefins in the wax isomerized oil are
hydrogenated and oxidation stability and hue of a lubricating oil
are improved, by hydrorefining. Such hydrorefining can be performed
by, for example, using a hydrorefining catalyst.
[0115] It is preferable that the hydrorefining catalyst be one
obtained by supporting a Group 6 metal, a Group 8 to 10 metal, or a
mixture thereof on the metal oxide carrier. Example of a preferable
metal is a noble metal, particularly platinum, palladium, and a
mixture thereof In a case where such a metal mixture is used, there
may be present as a bulk metal catalyst where the amount of metals
is 30% by mass or more based on that of the catalyst. It is
preferable that the content of the non-noble metals in the catalyst
is 20% by mass or less and that of noble metals in the catalyst is
1% by mass or less. The metal oxide carrier may be either amorphous
or crystal. Specific examples are weak-acidic oxides such as
silica, alumina, silica-alumina or titania, and alumina is
preferable. It is preferable to use a hydrorefming catalyst where a
metal having a relatively strong hydrogenation function is
supported on a porous carrier, from the viewpoint of saturation of
an aromatic compound.
[0116] Examples of a preferable hydrorefining catalyst are a
mesoporous material belonging to an M41S class or a series of
catalysts thereof A series of M41S catalysts are each a mesoporous
material having a high content ratio of silica, and specific
examples thereof include MCM-41, MCM-48 and MCM-50. Such a
hydrorefining catalyst has a pore size of 15 to 100 .ANG., and
MCM-41 is particularly preferable. MCM-41 corresponds to an
inorganic, porous non-layered phase having a hexagonal arrangement
of evenly sized pores. The physical structure of MCM-41 is like a
bundle of straws where the diameter of a straw opening (the cell
diameter of a pore) is in the range from 15 to 100 .ANG.. MCM-48
has a cubic symmetry and MCM-50 has a layered structure. MCM-41 can
be prepared with pore openings different in size falling within a
mesoporous range. The mesoporous material may have a metal
hydrogenation component being at least one Group 8, 9 or 10 metal,
and the metal hydrogenation component is preferably a noble metal,
particularly a Group 10 noble metal, most preferably Pt, Pd, or a
mixture thereof.
[0117] With respect to the hydrorefining conditions, the
temperature is preferably 150 to 350.degree. C., more preferably
180 to 250.degree. C., the total pressure is preferably 2859 to
20786 kPa (about 400 to 3000 psig), the liquid hourly space
velocity is preferably 0.1 to 5 hr, more preferably 0.5 to 3
hr.sup.-1, and the hydrogen/oil ratio is preferably 44.5 to 1780
m.sup.3/m.sup.3 (250 to 10,000 scf/B). The above conditions are
merely examples, and it is preferable for the hydrorefining
conditions to be appropriately selected depending on the
differences in raw material and treatment apparatus.
[0118] In a case where the wax isomerized oil is fractionally
distilled to a fraction having a desired viscosity grade, the
distillation conditions are not particularly limited, and it is
preferable to be performed by, for example, distillation at normal
pressure (or distillation under pressure) for distilling off a
light fraction from the wax isomerized oil, and distillation under
reduced pressure for fractionally distilling a desired fraction
from a bottom oil in the distillation at normal pressure.
[0119] It is possible in distillation to obtain a plurality of
lubricating oil fractions by setting a plurality of cut points and
distilling under reduced pressure a bottom oil obtained by
distilling the wax isomerized oil by distillation at ambient
pressure (or distillation under pressure). Examples include a
method involving obtaining a fraction whose boiling point range at
normal pressure is 330 to 410.degree. C., with a kinematic
viscosity at 100.degree. C. of 2.7 mm.sup.2/s as a target value, in
order to acquire a wax isomerized oil corresponding to 70 Pale
suitable as a lubricating base oil for ATF or a shock absorber
fluid; a method involving obtaining a fraction whose boiling point
range at normal pressure is 410 to 460.degree. C., with a kinematic
viscosity at 100.degree. C. of 4.0 mm.sup.2/s as a target value, in
order to acquire a lubricating base oil corresponding to SAE10
suitable as a lubricating base oil for an engine oil satisfying the
standard of the API group III; and a method involving collecting a
fraction whose boiling point range is 330.degree. C. or less, with
a kinematic viscosity at 100.degree. C. of 2.0 mm.sup.2/s as a
target value, in order to acquire a wax isomerized oil
corresponding to VG6.
[0120] The wax isomerized oil according to the present embodiment
exhibits a low traction coefficient as compared with a conventional
wax isomerized oil equivalent in viscosity and viscosity index.
[0121] The viscosity grade of the wax isomerized oil, according to
the present embodiment, is not particularly limited, and the
kinematic viscosity at 100.degree. C. is preferably 1.5 mm.sup.2/s
or more, more preferably 1.8 mm.sup.2/s or more, further preferably
2.0 mm.sup.2/s or more. On the other hand, the upper limit of the
kinematic viscosity at 100.degree. C. has particularly no
limitation, but is preferably 20 mm.sup.2/s or less, more
preferably 15 mm.sup.2/s or less, further preferably 10 mm.sup.2/s
or less, particularly preferably 4 mm.sup.2/s or less.
[0122] It is possible in the present embodiment to separately take
and use a wax isomerized oil whose kinematic viscosity at
100.degree. C. is in the following range, by distillation or the
like. [0123] (I) a wax isomerized oil whose kinematic viscosity at
100.degree. C. is 1.5 mm.sup.2/s or more and less than 2.3
mm.sup.2/s, more preferably 1.8 mm to 2.1 mm.sup.2/s [0124] (II) a
wax isomerized oil whose kinematic viscosity at 100.degree. C. is
2.3 mm.sup.2/s or more and less than 3.0 mm.sup.2/s, more
preferably 2.4 to 2.8 mm.sup.2/s [0125] (III) a wax isomerized oil
whose kinematic viscosity at 100.degree. C. is 3.0 to 20
mm.sup.2/s, more preferably 3.2 to 11 mm.sup.2/s, further
preferably 3.5 to 5 mm.sup.2/s, particularly preferably 3.6 to 4
mm.sup.2/s
[0126] The traction coefficient of the wax isomerized oil in the
present embodiment is measured by using a steel ball and a steel
disc as test pieces under conditions of a load of 20 N, a test oil
temperature of 25.degree. C., a circumferential velocity of 0.52
m/s and a slip ratio of 3%.
[0127] The wax isomerized oil according to the present embodiment
can have low traction coefficient. The traction coefficient of the
wax isomerized oil according to the present embodiment can be
appropriately selected depending on the viscosity grade, and, for
example, the traction coefficient of the above-described wax
isomerized oil (I) is preferably 0.0024 or less, more preferably
0.0023 or less. The traction coefficient of the above-described wax
isomerized oil (II) is preferably 0.0024 or less, more preferably
0.0023 or less. The traction coefficient of the above-described wax
isomerized oil (III) is preferably 0.0026 or less, more preferably
0.0025 or less. When the traction coefficient is in the
above-described numerical value range, it is preferable from the
viewpoint of energy conservation properties because it is possible
to ensure low friction properties. On the other hand, the lower
limit of the traction coefficient has no limited, but may be, for
example, 0.001 or more.
[0128] The viscosity index of the wax isomerized oil according to
the present embodiment can be appropriately selected depending on
the viscosity grade. For example, the viscosity index of the
above-described isomerized oil (I) is preferably 105 to 150, more
preferably 110 to 140, further preferably 115 to 135. The viscosity
index of the above-described isomerized oil (II) is preferably 120
to 160, more preferably 125 to 150, further preferably 130 to 150.
The viscosity index of the above-described isomerized oil (III) is
preferably 140 to 180, more preferably 145 to 170. When the
viscosity index is in the above-described range, it is preferable
from the viewpoint of energy conservation properties because it is
possible to ensure excellent viscosity-temperature characteristics.
The viscosity index mentioned in the present invention means a
viscosity index measured according to JIS K 2283-1993.
[0129] The density at 15.degree. C. (.rho..sub.15, unit:
g/cm.sup.3) of the wax isomerized oil, according to the present
embodiment, can be appropriately selected depending on the
viscosity grade. For example, the p.sub.15 of the above-described
isomerized oil (I) is preferably 0.82 g/cm.sup.3 or less, more
preferably 0.81 g/cm.sup.3 or less, further preferably 0.80
g/cm.sup.3 or less. The .rho..sub.15 of the above-described
isomerized oils (II) and (III) is preferably 0.84 g/cm.sup.3 or
less, more preferably 0.83 g/cm.sup.3 or less, further preferably
0.82 g/cm.sup.3 or less. When the density at 15.degree. C. is in
the above-described range, not only viscosity-temperature
characteristics and heat-oxidation stability, but also
volatilization preventing properties and low-temperature viscosity
characteristics are excellent, and, in a case where an additive is
compounded into the wax isomerized oil, it is possible to
sufficiently ensure the efficacy of the additive. The density at
15.degree. C. mentioned in the present invention means a density
measured at 15.degree. C. according to JIS K 2249-1995.
[0130] The pour point of the wax isomerized oil, according to the
present embodiment, can be appropriately selected depending on the
viscosity grade. For example, the pour point of the above-described
isomerized oil (I) is preferably -10.degree. C. or less, more
preferably -20.degree. C. or less, further preferably -30.degree.
C. or less. The pour point of the above-described isomerized oil
(II) is preferably -10.degree. C. or less, more preferably
-15.degree. C. or less, further preferably -20.degree. C. or less.
The pour point of the above-described isomerized oil (III) is
preferably -10.degree. C. or less, more preferably -15.degree. C.
or less. When the pour point of the isomerized oil is in the
above-described numerical value range, it is preferable from the
viewpoint of energy conservation properties because it is possible
to sufficiently ensure low-temperature fluidity of a lubricating
oil using the isomerized oil. The pour point mentioned in the
present invention means a pour point measured, according to JIS K
2269-1987.
[0131] The cloud point of the wax isomerized oil, according to the
present embodiment, depends on the viscosity grade, and the cloud
point of the above-described wax isomerized oil (I), is, for
example, preferably -15.degree. C. or less, more preferably
-17.5.degree. C. or less. The cloud point of the above-described
wax isomerized oil (II) is preferably -10.degree. C. or less, more
preferably -12.5.degree. C. or less. The cloud point of the
above-described wax isomerized oil (III) is preferably -10.degree.
C. or less. When the cloud point of the wax isomerized oil is in
the above-described numerical value range, it is preferable from
the viewpoint of energy conservation properties because it is
possible to sufficiently ensure low-temperature fluidity of a
lubricating oil using the wax isomerized oil. The cloud point
mentioned in the present invention means a cloud point measured
according to "4. Testing method for testing cloud point" in JIS K
2269-1987.
[0132] Furthermore, in a case where gas chromatographic analysis is
performed with respect to the wax isomerized oil, according to the
present embodiment, the carbon number distribution of the
hydrocarbon compound included in the wax isomerized oil can be
appropriately selected depending on the viscosity grade. For
example, the carbon number distribution in the above-described wax
isomerized oil (I) is preferably 10 to 35, more preferably 15 to
30. The carbon number distribution in the above-described wax
isomerized oil (II) is preferably 12 to 40, more preferably 15 to
35. The carbon number distribution in the above-described wax
isomerized oil (III) is preferably 15 to 50, more preferably 18 to
45.
[0133] In a case where gas chromatographic analysis is performed
with respect to the wax isomerized oil according to the present
embodiment, the average number of carbon atoms of the hydrocarbon
compound included in the wax isomerized oil can be appropriately
selected depending on the viscosity grade. For example, the average
number of carbon atoms in the above-described wax isomerized oil
(I) is preferably 15 to 25, more preferably 18 to 22. The average
number of carbon atoms in the above-described wax isomerized oil
(II) is preferably 15 to 30, more preferably 20 to 25. The average
number of carbon atoms in the above-described wax isomerized oil
(III) is preferably 20 to 40, more preferably 25 to 30. When the
carbon number distribution and/or the average number of carbon
atoms are/is in the above-described numerical value range(s), it is
preferable from the viewpoint of energy conservation properties
because it is possible to further reduce the traction
coefficient.
[0134] The wax isomerized oil according to the present embodiment
is obtained using the ethylene polymer wax as a raw material, as
described above, and most of the constituent hydrocarbon compounds
of the ethylene polymer wax correspond to the hydrocarbon compound
having an even number of carbon atoms. Accordingly, the wax
isomerized oil is not evenly balanced in contents of the
hydrocarbon compound having an even number of carbon atoms and the
hydrocarbon compound having an odd number of carbon atoms. A
specific content of the hydrocarbon compound having an even number
of carbon atoms with respect to the constitution of such
hydrocarbon compounds included in the wax isomerized oil is not
particularly limited, and is, for example, preferably less than 50%
by mass, more preferably 45% by mass or less, further preferably
43% by mass or less based on the total amount of the wax isomerized
oil.
[0135] The carbon number distribution, the average number of carbon
atoms, and the content of the hydrocarbon compound having an even
number of carbon atoms are respective values determined by
performing gas chromatographic analysis with respect to the wax
isomerized oil, under the same conditions as in the above-described
raw material wax. In measurement, a mixed standard sample of normal
paraffin having 5 to 50 carbon atoms as a basis sample is subjected
to measurement under the same conditions. Then, the carbon number
distribution and the ratio of each component with respect to each
number of carbon atoms, of the wax isomerized oil, are measured
with reference to the resulting chromatogram. The sum of the
products of the ratio of each component with respect to each number
of carbon atoms and such each number of carbon atoms is determined,
and defined as the average number of carbon atoms. In the case of
hydrocarbon compounds having the same number of carbon atoms, a
hydrocarbon compound having the highest boiling point (the longest
distillation time) is here normal paraffin, as described above, and
thus a peak present between the peak corresponding to the
distillation time of a hydrocarbon compound having n carbon atom(s)
and the peak corresponding to the distillation time of a
hydrocarbon compound having n-1 carbon atom(s) in measurement of
the above-described basis sample is defined to correspond to
non-normal paraffin having n carbon atom(s), in calculation of the
number of carbon atoms.
[0136] The wax isomerized oil according to the present embodiment
is excellent in energy conservation properties, and can be
preferably used as a lubricating base oil for various applications.
Specific examples of such an application of the wax isomerized oil,
according to the present embodiment, are a lubricating oil
(lubricating oil for an internal combustion engine) for use in an
internal combustion engine such as a gasoline engine for a
passenger automobile, a gasoline engine for a two-wheeled vehicle,
a diesel engine, a gas engine, an engine for a gas heat pump, a
marine engine or an electrical generation engine, a lubricating oil
(oil for a drive transmission apparatus) for use in a drive
transmission apparatus such as an automatic transmission, a manual
transmission, a continuously variable transmission or a final
reduction gear, a hydraulic oil for use in a hydraulic apparatus
such as a shock absorber or a construction machine, and a
compressor oil, a turbine oil, an industrial gear oil, a
refrigerator oil, a rust-proof oil, a heat medium oil, a gas holder
sealing oil, a bearing oil, a paper machine oil, a working machine
oil, a slip guide surface oil, an electrical insulating oil, a
cutting oil, a press oil, a rolling oil and a heat treatment oil.
The wax isomerized oil according to the present embodiment is used
for such an application to thereby make it possible to achieve
enhancements in properties such as energy conservation properties
of each lubricating oil.
[0137] The wax isomerized oil according to the present embodiment
may be used alone as the lubricating base oil or the wax isomerized
oil according to the present embodiment may be used in combination
with other one or two or more base oils, in the above applications.
In a case where the wax isomerized oil according to the present
embodiment is used in combination with other base oil(s), the
proportion of the wax isomerized oil according to the present
embodiment in such a mixed base oil is preferably 30% by mass, more
preferably 50% by mass or more, further preferably 70% by mass or
more.
[0138] Such other base oil for use in combination with the wax
isomerized oil according to the present embodiment is not
particularly limited, and examples of a mineral base oil include
mineral oils classified to Group Ito Group III in the API
classification.
[0139] Examples of a synthetic base oil include poly
.alpha.-olefins or hydrogenated products thereof, isobutene
oligomers or hydrogenated products thereof, isoparaffins,
alkylbenzenes, alkylnaphthalenes, diesters (ditridecyl glutarate,
di-2-ethylhexyl adipate, diisodecyl adipate, ditridecyl adipate,
di-2-ethylhexyl sebacate, and the like), polyol esters
(trimethylolpropane caprylate, trimethylolpropane pelargonate,
pentaerythritol 2-ethylhexanoate, pentaerythritol pelargonate, and
the like), polyoxyalkylene glycols, dialkyl diphenyl ethers, and
polyphenyl ethers, and among them, poly .alpha.-olefins are
preferable. Examples of such poly .alpha.-olefins typically include
oligomers or co-oligomers of .alpha.-olefins of 2 to 32, preferably
6 to 16 carbon atoms (1-octene oligomer, decene oligomer,
ethylene-propylene co-oligomer, and the like) and hydrogenated
products thereof.
[0140] The method for producing such poly .alpha.-olefins is not
particularly limited, and examples thereof include a method
involving polymerizing .alpha.-olefins in the presence of a
polymerization catalyst such as a Friedel-Crafts catalyst including
a complex of aluminum trichloride or boron trifluoride with water,
any alcohol (ethanol, propanol, butanol, or the like), any
carboxylic acid or any ester thereof.
[0141] It is possible to, if necessary, compound various additives
to the wax isomerized oil according to the present embodiment or a
mixed base oil of the wax isomerized oil with other base oil. Such
an additive is not particularly limited, and it is possible to
compound any additive conventionally used in the lubricating oil
field. Specific examples of such an additive of a lubricating oil
include an antioxidant, an ashless dispersant, a metallic cleaning
agent, an extreme-pressure agent, an anti-wear agent, a viscosity
index improver, a pour point depressant, a friction adjuster, an
oiliness agent, a corrosion inhibitor, a rust inhibitor, a
demulsifier, a metal deactivating agent, a seal swelling agent, a
defoamer and a colorant. Such additives may be used singly or in
combinations of two or more thereof.
EXAMPLES
[0142] Hereinafter, the present invention will be more specifically
described based on Examples and Comparative Examples, but the
present invention is not limited to the following Examples at
all.
[0143] [Measurement of Number Average Molecular Weight (Mn) and
Weight Average Molecular Weight (Mw)]
[0144] Two columns (product name: PL gel 10 .mu.m MIXED-B LS
manufactured by Polymer Laboratories Ltd.) were connected to a
high-temperature GPC apparatus (product name: PL-20 manufactured by
Polymer Laboratories Ltd.), thereby providing a differential
refractive index detector. To 5 mg of a sample was added 5 ml of
o-dichlorobenzene, and heated and stirred at 140.degree. C. for
about 1 hour.
[0145] Such a sample thus dissolved was subjected to measurement by
setting the flow rate to 1 ml/min and the temperature of a column
oven to 140.degree. C. Conversion of the molecular weight was
performed based on the calibration curve created with standard
polystyrene, and the molecular weight in terms of polystyrene was
determined.
[0146] [Calculation of Catalyst Efficiency]
[0147] The catalyst efficiency was calculated by dividing the
weight of the resulting oligomer by the number of moles of a
catalyst loaded.
Example 1
[0148] An iron compound (50 mg) represented by formula (1a) and a
ligand (19 mg) represented by formula (2a) were introduced into a
500-mL eggplant flask and dry toluene (200 mL) was added thereto,
under a nitrogen stream. A solution of methylaluminoxane in hexane
(3.64 M solution, 11 mL) was added to the toluene solution, thereby
producing solution (A).
[0149] Dry toluene (8 L) and a solution of methylaluminoxane in
hexane (3.64 M solution, 2.8 mL) were introduced under a nitrogen
stream into a 20-L autoclave equipped with an electromagnetic
induction stirrer sufficiently dried at 110.degree. C. under
reduced pressure in advance, and the temperature was adjusted to
30.degree. C.
[0150] Solution (A) was introduced into the above-described
autoclave, thereby producing an ethylene polymerization catalyst.
The proportion of methylaluminoxane contained in the resulting
ethylene polymerization catalyst was 500 equivalents relative to
the number of moles of the iron compound.
[0151] Ethylene (30.degree. C. and 1 MPa) was continuously
introduced into the autoclave which solution (A) was introduced.
After 9 hours, such introduction of ethylene was stopped, the
unreacted ethylene was purged, and ethanol (100 mL) was added to
deactivate the ethylene polymerization catalyst. The autoclave was
opened, the content was transferred to a 20-L eggplant flask, and
the solvent was distilled off under reduced pressure to thereby
obtain semi-solid ethylene oligomer wax (WAX 1). The catalyst
efficiency (C.E.) was 60824 kg Olig/Fe mol. The Mn, Mw and Mw/Mn of
WAX 1 obtained were 490, 890 and 1.8, respectively. The results of
the content of normal paraffin and the content of the hydrocarbon
compound having an even number of carbon atoms (content of an even
number of carbon atoms), in WAX 1 obtained, as obtained by gas
chromatographic analysis, are shown in Table 1.
[0152] WAX 1 was separated by distillation to thereby obtain a
fraction whose boiling point range was 350 to 450.degree. C.
Hydrocracking of the resulting fraction was performed in the
presence of a hydrocracking catalyst under conditions of a reaction
temperature of 350.degree. C., a hydrogen partial pressure of 5 MPa
and a liquid hourly space velocity of 1.0 hr.sup.-1, thereby
obtaining a cracked product. As the hydrocracking catalyst, a
catalyst where 3% by mass of nickel and 15% by mass of molybdenum
were supported on an amorphous silica-alumina carrier
(silica:alumina=20:80 (mass ratio)) was used in the state of being
sulfurized. The resulting cracked product was hydroisomerized by
using a zeolite-based hydroisomerization catalyst whose noble metal
content was adjusted to 0.1 to 5% by mass, under conditions of a
reaction temperature of 330.degree. C., a hydrogen partial pressure
of 5 MPa and a liquid hourly space velocity of 1.0 hr.sup.-1,
thereby obtaining a wax isomerized oil. Subsequently, the resulting
wax isomerized oil was distilled under reduced pressure, thereby
obtaining a wax isomerized oil corresponding to 70 Pale.
Characteristics of the resulting wax isomerized oil are shown in
Table 2. In Table 2, "Carbon number distribution", "Average number
of carbon atoms" and "Content of even number of carbon atoms" are
each obtained by performing gas chromatographic analysis with
respect to the resulting wax isomerized oil, and "Traction
coefficient" is a value measured by using a steel ball and a steel
disc as test pieces under conditions of a load of 20 N, a test oil
temperature of 25.degree. C., a circumferential velocity of 0.52
m/s and a slip ratio of 3% (the same applies hereinafter).
Comparative Example 1-1
[0153] FT wax (WAX 2) whose content of paraffin was 93% by mass and
which had a carbon number distribution of 18 to 60 was used as a
raw material wax. The results of the content of normal paraffin and
the content of the hydrocarbon compound having an even number of
carbon atoms (content of an even number of carbon atoms), in WAX 2,
as obtained by gas chromatographic analysis, are shown in Table
1.
[0154] A wax isomerized oil was obtained by using WAX 2 according
to the same method as in Example 1. Characteristics of the
resulting wax isomerized oil are shown in Table 2.
Comparative Example 1-2
[0155] WAX 1 was separated by distillation to thereby obtain a
fraction whose boiling point range was 250 to 500.degree. C.
Hydrocracking of the resulting fraction was performed in the
presence of a hydrocracking catalyst under conditions of a reaction
temperature of 350.degree. C., a hydrogen partial pressure of 5 MPa
and a liquid hourly space velocity of 1.0 hr-1, thereby obtaining a
cracked product. As the hydrocracking catalyst, a catalyst where 3%
by mass of nickel and 15% by mass of molybdenum were supported on
an amorphous silica-alumina carrier (silica:alumina=20:80 (mass
ratio)) was used in the state of being sulfurized. Subsequently,
the resulting cracked product was distilled under reduced pressure,
thereby obtaining a fraction corresponding to 70 Pale. Solvent
dewaxing of the fraction with a mixed solvent of methyl ethyl
ketone:toluene=1:1 under conditions of a ratio of solvent:oil=4:1
and a filtration temperature of -25.degree. C. was performed,
thereby obtaining a solvent dewaxed oil. Characteristics of the
resulting solvent dewaxed oil are shown in Table 2.
TABLE-US-00001 TABLE 1 Name of raw material wax WAX 1 WAX 2 Content
of normal paraffin 71 93 (% by mass) Content of even number 100 50
of carbon atoms (% by mass)
TABLE-US-00002 TABLE 2 Comparative Comparative Example 1 Example
1-1 Example 1-2 Raw material oil WAX 1 WAX 2 WAX 1 Fractional
distillation 350-450 350-450 250-500 of raw material, .degree. C.
Viscosity grade 70Pale 70Pale 70Pale Density (15.degree. C.), 0.81
0.81 0.81 g/cm.sup.3 Kinematic viscosity 2.66 2.6 2.66 (100.degree.
C.), mm.sup.2/s Viscosity index 132 127 128 Pour point .degree. C.
-22.5 -20 -25 Carbon number distribution 17-33 17-35 18-35 Average
number of 23.9 23.7 23.9 carbon atoms Even number of 42 50 44
carbon atoms, % by mass Traction coefficient 0.0023 0.0025
0.0025
Example 2
[0156] A wax isomerized oil was obtained according to the same
method as in Example 1 except that, in Example 2, WAX 1 was
separated by distillation and a fraction whose boiling point range
420 to 500.degree. C. was used, and the resulting wax isomerized
oil was distilled under reduced pressure, to thereby obtain a wax
isomerized oil corresponding to SAE-10. Characteristics of the wax
isomerized oil obtained in Example 2 are shown in Table 3.
Comparative Example 2-1
[0157] A wax isomerized oil was obtained according to the same
method as in Example 2 except that WAX 2 was used in Comparative
Example 2-1. Characteristics of the wax isomerized oil obtained in
Comparative Example 2-1 are shown in Table 3.
Comparative Example 2-2
[0158] A solvent dewaxed oil was obtained according to the same
method as in Comparative Example 1-2 except that a fraction
corresponding to SAE-10 was obtained in distillation under reduced
pressure of a cracked product in Comparative Example 2-2.
Characteristics of the solvent dewaxed oil obtained in Comparative
Example 2-2 are shown in Table 3.
TABLE-US-00003 TABLE 3 Comparative Comparative Example 2 Example
2-1 Example 2-2 Raw material oil WAX 1 WAX 2 WAX 1 Fractional
distillation 420-500 420-500 250-500 of raw material, .degree. C.
Viscosity grade SAE-10 SAE-10 SAE-10 Density (15.degree. C.), 0.81
0.81 0.81 g/cm.sup.3 Kinematic viscosity 3.91 3.91 3.9 (100.degree.
C.), mm.sup.2/s Viscosity index 145 142 142 Pour point, .degree. C.
-20 -20 -20 Carbon number distribution 21-39 21-40 20-41 Average
number of 28.5 28.7 28.6 carbon atoms Even number of 42 50 44
carbon atoms, % by mass Traction coefficient 0.0025 0.0030
0.0027
Example 3
[0159] A wax isomerized oil was obtained according to the same
method as in Example 1 except that, in Example 3, WAX 1 was
separated by distillation and a fraction whose boiling point range
was 300 to 440.degree. C. was used, and the resulting wax
isomerized oil was distilled under reduced pressure, to thereby
obtain a wax isomerized oil corresponding to VG6. Characteristics
of the wax isomerized oil obtained in Example 3 are shown in Table
4.
Comparative Example 3-1
[0160] A wax isomerized oil was obtained according to the same
method as in Example 3 except that WAX 2 was used in Comparative
Example 3-1. Characteristics of the wax isomerized oil obtained in
Comparative Example 3-1 are shown in Table 4.
Comparative Example 3-2
[0161] A solvent dewaxed oil was obtained according to the same
method as in Comparative Example 1-2 except that a fraction
corresponding to VG6 was obtained in distillation under reduced
pressure of a cracked product in Comparative Example 3-2.
Characteristics of the solvent dewaxed oil obtained in Comparative
Example 3-2 are shown in Table 4.
TABLE-US-00004 TABLE 4 Comparative Comparative Example 3 Example
3-1 Example 3-2 Raw material oil WAX 1 WAX 2 WAX 1 Fractional
distillation 300-440 300-440 250-500 of raw material, .degree. C.
Viscosity grade VG6 VG6 VG6 Density (15.degree. C.), 0.79 0.79 0.78
g/cm.sup.3 Kinematic viscosity 2.03 2.01 2.00 (100.degree. C.),
mm.sup.2/s Viscosity index 130 120 122 Pour point, .degree. C.
-32.5 -32.5 -32.5 Carbon number distribution 17-29 17-30 16-30
Average number of 20.7 20.9 20.5 carbon atoms Even number of 41 50
42 carbon atoms % Traction coefficient 0.0023 0.0026 0.0025
[0162] The wax isomerized oils (Examples 1 to 3) obtained by the
production method according to the present invention each exhibited
a low traction coefficient.
[0163] On the other hand, the wax isomerized oils according to
Comparative Examples 1-1, 2-1 and 3-1 where FT wax was used as a
raw material instead of the ethylene oligomer wax each resulted in
a high traction coefficient as compared with any wax isomerized oil
of an equivalent viscosity grade, obtained by the production method
according to the present invention.
[0164] The solvent dewaxed oils according to Comparative Examples
1-2, 2-2, and 3-2, which did not undergo any isomerization dewaxing
step by a hydroisomerization catalyst, each resulted in a high
traction coefficient as compared with any wax isomerized oil of an
equivalent viscosity grade, obtained by the production method
according to the present invention.
* * * * *