Note: Descriptions are shown in the official language in which they were submitted.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to processes for the pro-
ductior. of oligomers from olefins, and more particularly re-
lates to the production of oligomers from internal olefinsby means of a boron trifluoride catalyst.
2. Description of Related Methods
Friedel-Crafts catalysts have long been known to
oligomerize olefins. For example, see U. S. Patent 3,410,925
to Eby, et al. in which olefins are mixed with alkylatable
aromatic hydrocarbons over a Friedel-Crafts catalyst to form
an alkylation sludge which is then mixed with olefins having
3 to '8 carbon atoms which are also passed over the catalyst
to produce olefin dimers. U. S. Patent 3,652,706 to Saines,
et al. describes the polymerization of olefins having 2 to
20 carbon atoms over a Friedel-Crafts metal halide catalyst
plus a hydrogen form of mordenite to produce compounds hav-
ing a molecular weight between 700 and 2,500. Production of
a gasoline fuel composition is described in U. S. Patent
3,749,560 to Perilstein which occurs by reacting a mixture
of mono olefins (greater than 50 weight per cent alpha ole-
fins~ over a Friedel-Crafts catalyst heated to a temperature
around 145~C to produce oligomers having molecular weights
between 350 to l,500. Also, U. S. Patent 3,149,178 to
Hamilton, et al. reveals an improved method for making
polymerized olefin synthetic lubricants via a particular
distillation techni~ue of oligomers made from alpha mono
olefins using a Friedel-Crafts catalyst. Alpha olefins hav-
ing six to twelve carbon atoms may be dimerized in the pre-
- 30 sence of a Friedel-Crafts catalyst according to the method
--1--
described in U. S. Patent 4,172,855 to Shubkin, et al.
It is also known that the term "Friedel-Crafts cat
alysts" includes boron trifluoride among other metal halide-
type Lewis catalysts, see Kirk-Othmer Encyclopedia of Chemical
Technology, Third Edition, Vol. 11, pg 292. Boron trifluoride
has also been known to polymexize olefins, as seen in F. Albert
Cotton, et al., Advanced Inorqanic Chemistry: ~ Comprehensive
Text, Interscience Publishers, 1962, p. 191.
A number of U. S. patents have also used BF3 to
oligomerize olefins. Close study will revea~ that alpha ole-
fins are considered the only useful form. For example, U. S.
Patent 2,780,664 to Serniuk describes the reaction of conju-
gated dienes with mono alpha and internal olefins over BF3
promoted by an ether mixed with a halo aIkane diluent at a
temperature from -30 to 100C to produce oligomers suitable
for drying oils. Alpha olefins having from 5 to 20 carbon
atoms are oligomeri~ed using BF3 plus an alcohol or water
promoter as described in U. S. Patent 3,382,291 to Brennan.
In this patent, BF3 and a mixture of BF3 plus the promoter
complex are introduced in two separate streams. Another U. S.
patent by Brennan, 3,742,082, concerns the dimerization of
alpha olefins via BF3 which is promoted with phosphoric acid
or water at a temperature from 100 to 150C. U. S. Patent
3,763,244 to Shubkin, which describes the oligomerization of
n-alpha olefins having 6 to 16 carbon atoms over BF3 pro-
moted with water, at a temperature between 10 and 60C where
it is preferred that BF3 is added continuously.
Yet another U. S. patent to Brennan, 3,769,363,
describes the oligomerization of olefins having 6 to 12 car-
bon atoms using BF~ with a carboxylic acid promoter having
at least 3 carbon atoms at a temperature between 0 and20C to produce olefins heavy in trimer form. U. S.
Patent 3,780,128 also to Shubkin relates to the oligomer-
ization of alpha olefins having 6 to 16 carbon atoms in
which BF3 is employed in a molar excess of alcohol. U. S.
Patent 3,876,720 to Heilman, et al. describes a two-step
procedure by which alpha olefins having 8 to 12 carbon atoms
are converted to vinylidene olefins which are then reacted
over a 1:1 molar complex of BF3 and alcohol to produce
oligomerized vinylidene olefins. A method for oligomerizing
both short and long chain alpha olefins having from 14 to 20
carbon atoms simultaneously over BF3 with an alcohol or
water promoter at 0 to 60C with a monomer recycle is des-
cribed in U. S. Patent 4,225,739 to Nipe, et al. There is
also U. S. Patent 4,263,465 to Sheng, et al. which describes
a two-step process for reacting one-butene with a higher
alpha olefin over BF3 in the pres~nce of a proton donor at a
temperature from -30 to 50C to produce an oligomer having 8
to 18 carbon atoms. The intermediate oligomer i~ reacted
with other higher alpha mono olefins over the same catalyst
system from -30 to 60~C to produce oligomers having 20 to 40
carbon atoms. For more information on BF3-catalyzed olig-
omerization of alpha olefins, see Brennan, "Wide-Temperature
Range Synthetic Hydrocarbon Fluids," Ind. Eng. Chem. Prod.
Res. Dev. 19~0, Vol. l9, pp 2-6 and Shubkin, et al., "Olefin
Oligomer Synthetic Lubricants: Structure and Mechanism of
Formation," Ind. Eng. Chem. Prod. Res~ Dev. 1980, Vol. 19,
pp 15-19.
Two patents have been located which involve
the reaction of internal olefins over Friedel-Crafts cat-
--3--
alysts. U. S. Patent 4,167,S34 to Petrillo, et al. des-
cribes olefins which are both alpha and internal having from
10 to 15 carbon atoms which are reacted over Friedel-Crafts
catalysts between 20 and 200~C to produce oligomers. The
catalysts used in the examples of this patent are only AlCl3
and NaAlCl~. The internal olefins are also those that are
statis-tically distributed. Also, the oligomers found useful
therein seem to be the hydxogenated bottoms product after
the unreacted olefins are removed, without further dis-
tillation. U. S. Patent 4,218,330 to ~hubkin describes
hydrogenated dimers from alpha olefins having from 12 to 18
carbon atoms, especially 1-tetradecene, made u~ing a Friedel-
Crafts catalys-t, which includes therein boron trifluoride
with a promoter. Shubkin's method uses predominantly alpha
olefins, although the specification mentions that "fairly
large amounts of internal olefins can be tolerated ~ithout
adversely affecting the physical properties o~ the oligomer."
This last remark from Shubkin reveals the general feeling of
those working in the field that internal olefins do not pro-
duce oligomers with good properties for synthetic lu~ricants.For example, in U. S. Patent 3,952,071 to Isa, et al., it is
revealed that olefins may be oligomerized in the presence of
a mixture of a polyhydric alcohol derivative and an aluminum
halide. Isa, et al. mention that the olefin could be internal
or alpha although alpha olefins are -the only ones used in
the examples therein. U. S. Patent 3,947,509, also to Isa,
et al., also claims that internal olefins may be used over a
ketone and ester ether or alcohol promoted aluminum chloride
catalyst although only alpha olefins are used in the ex-
amples.
U. S. Patent 4,300,006 was issued on November 10,1981. It describes a process for producing a hydrocarbon
oil by contacting a mixture of alpha and at least 50 weight
per cent internal olefins with, a boron trifluoride dimeri-
zation catalyst. However, the productivity of useful pro-
ducts from the process revealed in U. S. Patent 4,300,006
is ~lite low. For example, an alkane diluent is found to
be necessary in the process described therein which, in
addition to distilling out the lights and the heavies to
obtain the lube oil, results in little useful product. Fur-
ther, this method requires a much longer reaction time and a
higher catalyst concentration than desired. It would be
beneficial if a method or producing synthetic lubricant com-
ponents could be devised which would overcome the afore-
mentioned disadvantages.
In the field of oligomerizing olefins for syntheticlubricants, it is a continual problem to produce olefins hav-
ing low viscosities at room temperature and below but which
have a high viscosity index and low volatility.
SUMMARY OF THE INVENTION
The invention relates to a process for oligomeriz-
ing mono olefins comprising contacting a mixture of olefins
having between 9 and 24 carbon atoms, inclusive, and having
'' A 99 weight per cent or more of internal olefins with a cat-
pre~e,rab/~-
alyst comprising boron trifluoride)~together with a promoterat a reaction temperature sufficient to effect oligomeri-
zation of said olefins.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
It has been surprisingly discovered that oligomers
which have an unusual blend of properties may be made by re-
--5--
acting predominantly internal mono olefins with boron tri-
fluoride and a promoter. It must be stressed that this dis-
covery has not been found by any of the other researchers in
the field. It is also important to note that predominantly
internal olefins are employed in the method of this in-
vention.
Generally, the olefins should have between 9 and
24 carbon atoms, inclusive. The internal olefins used here-
in have the double bond randomly distributed across the
molecule. In this context, the term "randomly distributed"
means that the double bond in the internal olefin is not
predominantly in any one location. For example, an olefin
mixture being comprised of a majority of alpha olefins would
be outside the scope of this definition since the double
bond would be located predominantly between the first and
second carbon atoms of the molecules. Likewise, since the
internal olefins used for oligomerization in the method of
U. S. Patent 4,300,006 are made by disproportionation of
alpha olefins, the double bond is located predo.minantly at
or near the center of the molecule, and such olefin feed-
stocks also fall outside the definition of having a "random
distribution" of the double bond. A random distribution in-
cludes the distribution one may obtain upon the dehydro~
genation of paraffins. One would expect a small amount of
alpha olefin to result from such a distribution. However,
one would also anticipate that the alpha olefin proportion
would be only about 0.1 weight per cent, with a maximum
value belng about 1.0 weight per cent. As a practical
matter, the feedstocks herein can be considered to be
- 30 entirely internal olefins.
The internal olefins may ~e generally expressed as
compounds having the formula RCH=C~R' where R and R' are the
same or different alkyl radicals of one to twenty one carbon
atoms. However, the total number of carbon atoms sho~ld not
exceed about twenty four and should not be less than nine.
The internal olefin mixtures are potentlally more available
than the pure cut alpha olefins and are potentially as cheap
or cheaper than the corresponding pure cut alphas. It will
be shown that the method of this invention affords higher
quality products and higher conversions than those obtained
with AlCl3 and AlCl~Na catalysts.
By careful selection of the molecular weight of
the feed olefins and the reaction conditions, it was found
that a synthetic lubricant base oil with a specific ~is-
cosity can be made by the method of this invention which hassuperior proper-ties o~er those made by other methods. For
example, it has been found that a base oil having a 210F
viscosity of about 4 centistokes with excellent properties
can be made with internal olefins having 13 or 14 carbon
atoms. A l'four centistoke fluid" is a designation given to
fluids used in lubricating oil compositions which generally
have 210E' viscosities of about 4 centistokes.
The catalyst of choice is boron trifluoride. A
number of different kinds of promoters may be used, such as
alcohols, carboxylic acids or water. It is especially pre-
ferred that 1 butanol be used as the promoter. The temper-
ature range at which the oligomerization may be performed
successfully is between 25 and 150C, with an especially
preferred range between 65 to 105C. The pressure range of
- 30 the reaction may run from atmospheric to 1000 psig. The
oligomerization of the olefins may be conducted in a batch or
continuous mode. First, the experimental methods will be
described, and then the results will be tabulated.
COMPARATIVE EXAMPLES
A number of comparative oligomerization examples were
run using the procedures of U. S. Patent 4,167,534. It is
believed that this patent constitutes the closest prior art.
The examples herein were patterned after Examples 1, 5 and 7
therein. These examples were chosen because they represented
a wide variety of conditions, particularly temperature. The
primary variable in the comparative examples is the olefin feed
material, although sometimes twice the amount of AlC13 used
in the 4,167,534 patent is employed in an attempt to improve
the conversion.
Accorcling to the disclosure in U. S. Patent 4,167,534,
Example 1 is begun by heating the feedstock to 80C. The
feedstock is then added over 15 minutes with 1% AlC13. The
temperature is then raised to 100C and maintained for 100
minutes. The product is then discharged, separated from the
heavy catalytic layer, washed with caustic solution and then
distilled.
Example 5 begins by adding the olefin feed at room
temperature with 1% AlC13 in only one portion. The temperature
is allowed to rise on its own for 120 minutes. The product is
then discharged, separated from the heavy catalytic layer,
washed with caustic solution and distilled.
The feed in Example 7 of U. S. Patent 4,167,534 is
added at 13~C with 5% NaAlC14 over 90 minutes. The reaction
mass is then maintained at 130C Eor 60 minutes
further. The product is then discharged, separated from the
heavy catalytic layer, washed with caus-tic solution and dis-
tilled. The results of the comparative examples are shown
in Table I.
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With respect to the results outlined in Table I,
the conversion is a weight per cent of monomer oligomeIized
as determined by liquid chromatography. The weight per cent
of the bottoms as based on the olefin charged is given in
the next column. While these two columns of data generally
measure the same concept (notice the qualitative correlation),
the applicants prefer to use "% conversion" while the in-
ventors in U. S. Patent 4,167,534 used the "% bottoms" method.
Both are employed in the examples of Table I for comparative
purposes.
Kinematic viscosities at two standard temperatures
are given in centistokes. The viscosity index (VI) is the
change in viscosity with temperature such that the higher
the number, the lower is the change in viscosity with temp-
erature. Conversely, a low VI signifies a large change inviscosity with temperature. Pour point is a measure of the
lowest temperature, in degrees Fahrenheit, at which the
sample will begin to pour. Below that temperature the
composition may generally be regarded as a solid. The
thermogravimetric analysis (TGA~ is a measure of volatility
via measuring the weight per cent of sample remaining at
233C as the temperature is raised in a slow, uniform manner,
usually 10C per minute. An oligomer product should have a
TGA analysis with at least 80% of the sample remaining at
233C in order to have sufficiently low volatility to be use-
ful as a base stock for lube oil formulation.
EXAMPLES ILLUSTRATING THE INVENTION
The following examples illustrate the method of
the invention using BF3 as the catalyst and only internal
- 30 olefins as the olefin feed. Two examples are included using.
Cl4 alpha olefin as the feedstock to show that an unsuitable
oligomer mixture is produced. The oligomer from alpha ole-
fins having 14 carbon atoms (l-tetradecene) was deficient in
its low temperature properties for use in crankcase engine
oils. Generally, the viscosity at 25C should be 30 to 30.5
centistokes ~cs) or less while the C14 alpha olefin oligomer
was observed to be in the 32-33 cs range. The pour point of
a synthetic lubricant base oil candidate should be less than
-50F. These differences are exaggerated at -30C (the temp-
erature at which cold cranking viscosity tests are done) and
would result in a too viscous fluid at cold temperatures.
Preferably, a "4 centistoke fluid" (measured at
210F) should have a viscosity between 25 and 40 centistokes
at 25C, a viscosity between 3.5 and 5.0 centistokes at 210F,
a viscosity index of greater than 100, a pour point of less
than -50F and a thermoyravimetric analysis per cent remain-
ing at 233C value of greater than 80 weight per cent. It
is especially preferred that 4 centisto~e fluids have a
viscosity of between 25 and 34 centistokes at 25C, a vis-
cosity between 3.5 and ~.5 cs at 210F, a minimum viscosity
index of 110, a maximum pour point of less than -50F and a
thermogravimetric analysis (TGA) value of 86%, minimum.
-12-
EXAMPLE 12
A solution of 43.8g C13 14 15 random internal lin~
ear olefins (53.4% C13, 45.0% C14, 0.5% C15, 1.1% paraffi~s)
and 0.12g l~butanol in a nitrogen atmosphere was saturated
with BF3 at 25C by slow sparging for 25 minutes. Pot con-
tents were maintained at 25-27C by external cooling while
55 6g of a solution of 55.0g C13_14_15
1-butanol was added over 1 2/3 hours. ~oron trifluoride
saturation was maintained during this addition and for 1-3/4
hours thexeafter. Boron trifluoride introduction was stopped
and the pot contents were heated to 86C over a 1-3/4 hour
period, and maintained at 85-86~C for 1/2 hour. After cool
ing, 110 ml H20 was added; the contents were stirred rapidly
for 20 minutes, and the top layer was removed. It was washed
with 115 ml H20 and stripped on a rotary evaporator at 30 mm
Hg to a maximum bath temperature of 95C; 96.9g of a clear
light yellow liquid remained (98.3% recovery). Analysis by
gel permeation chromatography indicated 61.34% dimer, 25.13%
trimer, and 12.95% monomer, the bala~ce being higher olig-
omers.
2~
-13-
-, .
EXAMPLE 13
The product of Example 12 (93.8g) was hydrogenated
over 9.60g of a powdered Wi/Cu/Cr catalyst, which is described
in U. S. Patent 3,152,99B. The conditions included a pressure
of 1800 psig H2 and a temperature of predominantly 208C (with
temperature briefly reaching 316C).
Vacuum stripping was conducted at 0.9 mm Hg, with a
maximum head temperature of 105C and a maximum pot temperature
of 157C, to remove 11.89g of lighter components (~91% monomers).
The hydrogenated bottoms product consisted (GPC analysis) of
26.7% trimer, >67.8% dimer, and >3.41% monomer. The kinematic
viscosities at 25C, 100F, and 210F were 29.57, 18.26 and
3.89 centistokes, respectively. The pour point was measured
to be less than -50F. Thermogravimetric analysis indicated
81.3% of the sample remained at 233C.
~ -14-
5t9
EXAMPLE 14
This is essentially the same procedure as Example 12
except BF3 introduction was stopped when olefin/ l-butanol
introduction stopped. The heating period was for 2 hours at
90C. GPC analysis indicated 19.8% trimer, 62.2~ dimer and
17.94% monomer, the balance being higher oligomers.
Hydrogenation
In order to form materials which have adequate oxida-
tive stability for lubricants, the oligomerized olefins are
optionally hydrogenated either partially or totally. This
hydrogenation is done by procedures known to those skilled in
the art as exemplified by U. S. Patents 4,045,508; 4,013,736;
3,997,622 and 3,997,621. A particularly preferred catalyst
for this hydrogenation is a nickel-copper-chromia catalyst
described in U. S. Patent 3,152,998. As is well known, such
hydrogenations may be perEormed in either batch or continuous
modes.
When the instant inventive method was scaled up for
a pilot plant run, it was discovered that the resulting oligomer
mixture did not give the expected desirable properties seen in
the lab scale experiments. In the pilot plant scale-up, strip-
ping out the monomer was performed first and then hydrogenation
was conduc-ted over the nickel-copper-chromia catalyst described
above. Monomer removal was performed before hydrogenation
and recycled to the oligomerization step. However, during
the pilot plant stripping step over 50% of the oligomer
material came off overhead at temperatures starting at about
210C to about 282C at the finish in an attempt to obtain a
material with a good TGA (vola-tility) value. ~pparently, some
of the unhydrogenated oligomer mixture was thermally unstable
-- ~. .,
3 :\ f
" i/
and portions of it were reverting to monomers or intermedia-tes
and distilling off as volatiles. It is, therefore, importan-t
that monomer removal be accomplished at as mild conditions as
possible; that is~ the reboiler or pot temperatures should
preferably be kept at or under 180C, preferably from 150C
to 180C or 160C to 180C, when stripping out monomer.
While the methods of others in the field include a
distillation step after hydrogenation procedure to obtain pro-
ducts of various 210F viscosities, i-t is much preferred in the
method of the invention that no fur-ther distilla-tion be
conducted. In other words, the monomer-stripped, hydrogenated
bottoms are the desired synthetic lubricant components. Thus
the method of this invention does not require the customary
distillation step, yet surprisingly produces a synthetic
lubricant component that has excellent properties and performs
in a superior fashion. ~Iowever, it is also anticipated that
one skilled in the art may find subsequent distillation useful
in the practice of the method of this invention.
~16-
EXAMPLES 15-26
The following examples illustrating the method of
the invention were conducted according to one of the follow-
ing procedures.
Procedure A
Examples 15 through 18 used the following experi-
mental procedure. To a 390 ml stainless steel clave (316
SS) was charged 158.6g of olefin and 1.4g of 1-butanol. The
clave was sealed and hea-ted to approximately 98C at which
time BF3 gas was introduced in amounts ranging from 3.1 to
4.4g (average 3.8g BF3 per run). The reaction was stirred
and allowed to exotherm on its own (no cooling). The re-
action was stirred for 60 minutes (time measured from first
BF3 addition and BF3 added over a 3-6 minute period) and
then cooling water turned on. The cool reaction mixture was
neutralized with 10 grams of Na2C03 and 100 ml H20. After
layer separation, the organic layer was washed twice more
with fresh water and dried. The oligomer was analyzed
(GPC/LC) for conversion and subjected to hydrogenation at
210C (2 hours), 2,000 psig H2 pressure in the presence of a
nickel-copper-chromium oxide catalyst (5% by weight basis
weight oligomer). Stripping the oligomers of monomer was
performed after hydrogenation in all of Examples 15-26 in a
manner similar to that of Example 27.
Procedure B
Examples 19 through 23 used procedure B which was
identical to Procedure A except that 0.7g butanol was used
(instead of 1.4g) and the amount of BF3 added ranged from
2.2 to 2.8g with a 2.5g average.
- 30
-17-
Procedure C
Examples 24 through 26 used Procedure C which was
identical to Procedure A except that the temperature of the
reaction mixture (olefin and promoter) before BF3 addition
was 65C (instead of 98C~ and the amount of BF3 added
ranged from 2.2g to 4.0g (3.0g average). Conversions and
properties of the oligomers are summarized in Table II.
It sho~ld be noted that the amount of catalyst
used in the method of this invention (1.4 to 2.8 weight per
cent of the olefin feed) is notably less than the amount of
catalyst used in other methods in the field, such as the
method disclosed in U. S. Patent 4,300,006 (2.6 to 6.1
weight per cent). In further contrast with the method of
this particular patent, no employment of a diluent, no
heavies or lights (except monomers) removed, and a shorter
reaction time are features of the inventive method. Another
difference lies in the fact that the method of U. S. Patent
4,300,006 uses a mixture of alpha and internal olefins hav~
ing carbon numbers that are ~uite different from each other,
unlike the instant method.
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It may be noted from inspection of Tables I and II
that alpha olefins produce invariably poorer oligomer mix-
tures than do internal olefins. No examples have higher vis-
cosities at both 210~F and 25~C than do the alpha olefin Ex-
amples 4, 8 and 11. It must be remembered that the inventivemethod herein has the requirement of using only int~rnal ole-
fins to obtain low viscosities, a feature not found in any
related method. It should also be pointed out that oligomers
made from alpha olefins (Examples 4, 8, 11, 23 and 26) have
rather high pour points, which make them unacceptable for
use in synthetic lubricants. The high pour point of Example
19 is thought to be an erroneous data point.
Secondly, it may be noted that the viscosities of
the BF3 catalyzed oligomers are all lower than those pro
duced by the method of U. S. Patent 4,167,534. In addition,
the conversions are much higher in the BF3 runs~ It is par-
ticularly surprising that C13 14 internal olefins (Examples
15, 19 and 24), having a higher average molecular weight
than the C11 14 internal olefins (Examples 16-18, 20-22 and
25) produce olefin mixtures having a lower viscosity than
the mixtures from C11 14 internals. These examples show how
the choice of molecular weight range of the olefin feedstock
greatly affects the properties o the product oligomers.
It is surprising that such low viscosities (relative
to other methods) may be found in oligomer mixtures that also
have low pour points and viscosity indexes and volatilities
comparable with those of other methods. It is precisely
such a blend of advantageous properties that is being sought
after in the field and which has not been discovered until
now.
-20-
In addition, it should be noted that the method
revealed in U. S. Patent 4,300,006, re ~ res that the dimeriza-
tion feedstock be obtained from the dispropor-tionation of
alpha olefins having 8 to 10 carbon atoms. As a result, the
dimerization feedstocks therein are a mixture of alpha and
internal olefins where the alpha olefins have slightly more
than half the carbon number of the corresponding internal olefin
and the internal olefins are highly symmetrical (being formed
from the disproportionation of two alpha olefins). For example,
Runs IX and XII therein oligomerize C14, C16 and C18 internal
olefins where the double bond is at or near the center of the
olefin molecule. The inventive method uses instead internal
olefins where the double bond is randomly distributed instead
of located near the center of a symmetrical mono olefin.
These differences in the feedstocks cause impc,rtant differences
in the properties in the resulting oligomers, as shown by the
following examples involving C14 internal olefin and C8 alpha
olefin as a mixed feedstock.
EXAMPLE 27
Oligomerization
The oligomerization of a 70 weight per cent C14
internal olefin and 30 weigh-t per cent C8 alpha olefin mixture
was accomplished over 2.5g of a boron trifluoride catalyst
with l.lg of 1-butanol as a protonic promoter and initiated
at 95.1C.
To a dry and clean 300 ml Hastelloy C autoclave were
added ll9g of C14 internal olefin from Shell Chemical Company's
Higher Olefin Process (SHOP). The double bond in these
internal olefins is randomly diskributed throughout
~ 21-
the molecule. Added at the same time were 51g of C8
alpha (l-octene from Aldrich Chemical Company, Inc.). At
the time, this was the closest approximation possible of
the U. S. Patent 4,300,006 feedstock. These additions
were followed by l.lg of l-butanol promoter. The clave
was sealed and the contents heated to 95.1C with stirring.
Starting at 95.1C, BF3 gas was introduced by adding four
shots of BF3 over an 11 minute period (2.5g total BF3
added) to the stirred reaction mixture. At the end of 17
minutes (measured from the first BF3 addition), the temp-
erature had risen 110.2C fox a maximum exotherm of 15.1C.
One hour after the first BF3 addition the reaction temper-
ature was 101.5C. The heat was turned off and cooling
water turned on. The reaction mixture was neutralized with
an aqueous Na2C03 solution and water washed twice more. The
organic layer was separated and dried by filtering through
folded filter paper to obtain a net weight of 156.3g.
Liquid chromatography analysis indicated 31.9% o~f the
material was C8, C14 or C16 and 27.5% was dimer C22 (from C8
and C14) and 32-2% was dimer C28 (from C14 and C14) while
8.4% was C36 or heavier. Conversion to material higher than
C16 was about 68.1%. The ratio of dimer to trimer and
heavies was 7.19:1.
~ydrogenation and Strip~in~
A l-liter stirred 316 stainless steel clave was
charged with 144.5g of oligomer from the previous step and
7.2g of a nickel-copper-chromium oxide hydrogenation cat-
alyst. The clave was flushed with hydrogen three or four
times and pressured to 1,000 psig with hydrogen. Subse-
quently,-the clave was heated to 210C (the pressure in-
creased to only 1,200 psig) and pressurized again to 2,000
psig with hydrogen. The reaction mixture was stirred at
210C for four hours during which the pressure remained at
2,000 psig. The hydrogenated oligomer was filtered and
137.3g subjected to high vacuum stripping. The ma-terial was
distilled through a jacketed column (with about 12 in. of
Goodloe packing) until the head temperature reached 105C at
0.06 mm Hg. The bottoms weighed 67.lg (49.6% of the total
material, overhead plus bottoms) and the overhead weighed
68.3g (50.4% of the total material). The bottoms product
had a 210F viscosity of 3.6 cs, a 25C viscosi-ty of 27.4
cs, a pour point of <-50F and a viscosity index of llO.
Liquid chromatography analysis indicated the presence of
25.5% dimer (C22), 60.2% dimer (C28) and 14.3% heavier
materials. The TGA of the bottoms product indicated
volatility was moderately high (85.0% sample remained at
233C in TGA of 10C/minute).
EXAMPLE 28
Oligomerizatlon
Oligomerization of a 70% Cl4 internal olefin - 30%
C8 alpha olefin mixture catalyzed by 2.2g of BF3 with l.lg
of l-butanol as a promoter was initiated at 94.9C. As in
the previous example, ll9g of Cl4 internal olefin were added
to a 300 ml clave along with 51g of C8 alpha olefin followed
by l.lg of 1-butanol. The clave was ~ealed and heated to
94.9C. Starting at 94.9C, BF3 gas was added over an
11 minute period (totalling 2.2g of BF3) to produce a 15.1C
maximum exotherm af-ter 16 minutes had elapsed after the
first BF3 addition. After a one hour reaction time measured
-~3-
from the first BF3 addition, the mixture was cooled and
neutralized with aqueous sodium carbonate. The organic
layer was separated and dried by filtering through folded
filter paper, to give a net weight of 162.5g. Liquid
chromatography analysis indicated 31.1% of the material was
C8, C14 or C16 27.2% was dimer C22 and 33.4% was dimer C28
while 8.3% was C36 or heavier. Conversion to materials
higher than C16 was 68.9%. The ratio of dimer to trimer and
heavies was 7.3Q:1.
Hydrogenation and Stripping
From the above step, 145.0g of the oligomer was
hydrogenated over 7.2g of nickel-copper-chromium oxide cat-
alyst. The hydrogenation was conducted at 210C and 2,000
psig from hydrogen for four hours. It was followed by fil-
tration and stripping as described in the previous example.The bottoms products amounting to 55.3% of the charge had a
25C viscosity of 25.7 cs and a 210F viscosity of 3.45 cs.
The pour point of the bottoms material was unacceptably high,
-40F, and the viscosity index was lO9Ø Liquid chroma-
tography analysis indicated 33.6% dimer C22 and 53.8% dimer
C28 and 12.6% heavies. The ratio of dimer to trimer and
heavies was thus 6.94:1. The TGA indicated 82.1% sample
remaining.
2~
-24-
EXAMPLE 29
Oligomerization
Oligomerization of a 70% C14 internal olefin - 30%
C8 alpha olefin mixture catalyzed by 2.5g BF3 and l.lg
l-butanol as promoter was conducted starting at 75.1C. To
a clean and dry 300 ml clave were added ll9g of C14 internal
olefin and 51g of C8 alpha olefin of the same sources as the
previous two examples, followed by l.lg of 1 butanol pro-
moter. The clave was sealed and heated to 75.1C and at
that temperature BF3 gas was added in increments (shots)
over a 10 minute period. Five separate shots were applied
to total 2.5g. Eleven minutes after the first BF3 addition,
the reaction temperature had risen to 100.7C (a maximum
exotherm of 25.6C). The reaction was held at 75C for 1.5
hours total and then cooled and worked up as in the previous
examples. The dry product from this lower temperature olig-
omerization had the following liquid chromatography analy-
sis: 12-7% of monomer (C8, C14 and C16), % 22
42.1% of C28 and 21.5% of trimer and heavies. Conversion to
materials greater than C16 was 87.3% with the dimer to trimer
and heavies ~eing 3.07:1.
H~drogenatlon and stxiPping
Hydrogenation of the oligomer from the above step
was completed at 210C, 4.0 hours and 2,000 psig hydrogen
pressure. Workup (filtration) followed by high vacuum strip-
ping afforded a bottoms product which amounted to 70.7% of
the charge and had the following properties: 210F viscos-
ity of 4.16 cs, 25C viscosity of 34.5 cs, pour point of
<-50F and a viscosity index of 124.2. The li~uid chroma-
- 30 tography analysis indicated 16.7% of the material was C22,
-25-
'
z~
56.8% was C2~ and 26.5% was heavies. TGA indicated the
sample had excellent volatility (90% remaining a-t 233C).
EXAMPLES 30 - 38
Examples 30 - 35 were conducted in a manner
similar to Examples 27 - 29 except that certain parameters
were changed as shown in Table III.
Examples 36 - 38 were conducted according to the
following procedure. Eighty three grams of delta 7 C14 and
36 g of delta 9 C18 internal olefin and 51g of C8 alpha ole-
fin were added to a 300 ml Hastelloy clave followed by l.lg
of 1-butanol. This olefin mixture is the closest approxi-
mation to the U. S. Patent 4,300,006 feedstocks ob-tainable
with the materials on hand. The clave was sealed and BF3
introduced in the indicated quantities. Workup was con-
ducted as usual involving an a~ueous Na~C03 wash followed by
two water washes and filtering the oryanic layer through
filter paper to dry it. Hydrogenation was accomplished at
210C and in the presence of 5% (by weight, basis olefin)
nickel catalyst and 2,000 psig hydrogen pressure for four
hours. The hydrogenation product was filtered and distilled
at high vacuum (<0.1 mm Hg) and to a head temperature of
110C. The bottoms product was submitted for analysis. The
results of this last set of comparative examples are summar-
ized in Table III.
-26-
%~
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XCC~C~ o l ~ 3~ ~20 3
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~,O q O I I I I ,+ ~ ~
O '' P-~ ~I V V V V
.
9 O O C~ D ~q C~
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-1 :~ I ~ O C`~ O ~ C`l
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Ll ~ ~J ~1 r-- L ~ `:t O L 0 1 1~
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H ~ ~ .,.j ~ ~ ~ 3~Cr) L'') ~--I O ~ ~ C~ ~ r~
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_~ ~ H ~ ~~qC~0~o ~ ~ 00 Cl~
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Cl:) H~1 ~ r ~ C ~ 1~ C~ D O
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P; ~ r~ LqC~LqLq~ D ~t ~ ~t L'~ r l L'')
X ~ ~ ~ ~-1 ~1C~t~~iC~i C~i ~i Li Lrl ~J Li Li
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O I ~ I O I ~-- I I I I I I I I I
~r-l ~ ~ ' C~ ~ ~ ' O ~t --I ~ O 0 1 0 ~ O LO O 00 C~
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C~ ~ 0~ 0~ 0~ 0~ 0~ 0~ 0~ 0
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~n ~ ~ ~J ~ ~ ~ ~ ~ ~ ~J ~ ~ ~ o~
a~ ~ 0~ 0~ O
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H I~ ~ + <¦ U
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c~ o~ o ~ c~ ~ ~ Lq ~D ~ C~
c~ ~ c~ cq ~q ~ ~ c~ ~ ~ ~ ~ -c
As can be seen from Table III, the product from
the feedstoc~s used in U. S. Patent 4,300,006 are unsuitable
for use as a synthetic lubricant without furthex distillation;
i.e., the bottoms product foun~ useful using the internal
olefin feedstocks of the invention are superior. Examples
32 - 38 have 210F and/or 25C viscosities and/or pour points
which are too high for use as 4 cs synthetic lubricants.
One skilled in the art would not expect these materials to
pass cold cranking tests. These same feedstocks, when run
at a higher temperature, produce a material with a low vis-
cosity index and a poor TGA value (see Example 31).
~ hus, it is determined by comparative examples
using the conditions of U. S. Patent 4,300,006 that the re-
sulting products would need to be distilled in ordex to meet
the 4.0 cs 210F viscosity re~uirement and apparently -the
cold cranking specifications as well.
The oligomer mixtures produced from Cl3 14 in-
ternal olefins via a promoted BF3 catalyst have proven to be
exceptional synthetic lubricant additives. As these mix-
tures have a 210F viscosity of about four centistokes, theyare considered "4 cs" fluids. A typical fluid of this in-
vention was compared with the commercially available 4
centistoke decene-1 derived polyalpha olefin (PAO). It
should be emphasized that the synthetic lubricant components
of the instant invention are preferably used without further
distillation after the monomer removal and hydrogenation steps.
In other words, the undistilled bottoms are the finished syn-
thetic lubricant component. The polyalpha olefins must be
distilled into "2 cs", "4 cs", "6 cs", etc. fractions before
- 30 they can be useful. Thus, the method of this invention does
-28-
not require a costly distillation step, which is an important
advantage over methods used by others in the field. Compari-
son of the properties of the fluids themselves are given in
Table IV. It may be seen that the fluid of this invention
(A) is somewhat less viscous than the polyalpha olefin fluid
(B) at the higher temperatures, though it is somewhat more
viscous at the lower temperatures. The viscosity index for
fluid A is somewhat less than for fluid B, but they are
generally comparable.
-29-
TABLE IV
PHYSICAL PROPERTIES OF 4 CFNTISTOKE FLUIDS
TESTS A * B
Kinematic Viscosity, cs at C F
100.0 212.0 3.81 3.90
40.0 104.0 17.0 17.1
Brookfield Viscosity,
centipoise at C F
-28.g -20.0 800 780
-40.0 -40.0 2340 2200
Viscosity Index 115 123
10 Pour Point, F** <-65 <-65
Gravity, API 40.8 41.1
Flash, C0C, F 430 435
CCS Viscosity, cP, -30C 980 930
ASTM color 0.0 0.0
Ash, % 0.001 0.001
*A = Fluid of this invention
B = Polyalpha olefin fluid
** = The actual pour points of the synthetic base oils were
less than 65F, the lowest temperature at which pour
points could be measured with available equipment.
~ 30
-30-
A measure of the volatility of the two fluids is
presented in Table V where it may be seen that oligomer A
is more volatile than fluid B.
TABLE V
A B
ASTM Eva~oration Test
Wt.% loss, 400F/6.5 hr 16.9 14.8
Thermal Gravimetric Anal~sis
Wt.% remaining at ~33C 91 92
Simulated Distillation
Wt.% off column, F
Initial Boiling Point 687 619
~ 710 737
4 71~ 761
6 723 767
8 727 771
730 773
736 775
741 778
7~5 785
762 800
Two motor oils were formulated having the same
proportions of the same components, except that formulation A
had 35 wt.% of a 4 cs fluid of this invention and formu-
lation B had 35 wt.% of the polyalpha olefin 4 cs fluid.
The rest of the components of the two formulations are
identical in type and proportion and include materials such
as mineral oils, dispersants, antioxidants, detergents,
friction modifiers, rust inhibitors, viscosity index im-
provers, pour point depressants and antifoamants. The
proportion of 35 wt.% is large enough for the additives to
- 30 have a profound effe~t on the behavior of the formulations
TABLE VI
PROPERTIES OF MOTOR OIL FORMULATIONS
API SW 30
A_ B Grade 1imits
Kin. vis. at 100C, cs 9.48 9.54 9.3 to 12.5
CCS vis. at -25C, cP 3500 3450 3500 max.
MBPT, ~C -34.7 -34.1 -30 max.
Pour Point -40 -45
TABLE VII
ENGINE TEST RESULTS
API SF/CC
TESTS A B GRADE LIMITS
SEO IIID TEST
Oxidation Stability Test
Vis. Inc.1, % at 64 Hr. 28 242 375 max.
Sludge 9.6 9.6 9.2 min.
Varnish 9.2 9.2 9.2 min.
ORLD2 8.0 7.1 4.8 min.
C~L3 Wear
Average, inch 0.0021 0.0011 0.0040 max.
Maximum, inch 0.0035 0.0027 0.0080 max.
Ring Sticking None None None
Lifter Sticking None None None
Cam +/or Lifter Scuffing None None None
Oil Consumption, quarts 5.0 6.47 6.38 max.
20 CRC L-38 TEST
Bearinq Corrosion
BWL~, mg 24.3 45.9,39.5 40.0 max.
CAT lH-2 TEST
Diesel Plston Deposits
Test
120 Hour TGF5, % 13.0 4.0
WTD6 25.6 71.9
480 Hour TGF, % 15.5 5.0 45 max.
WTD 96.5 137.1 140 max.
1Viscosity increase
2Oil ring land deposits
3Cam and Lifter
4Bearing Weight Loss
5Top Groove Filling
6Weighted Total Demerits
-32-
in testing. The properties of the motor oil formulations
are given in Table VI.
The results of the engine tests of the two formu-
lations are presented in Table VII. The engine tests run on
the two formulations are standard tests well known to those
skilled in the art. Sequence IIID tests are oxidation sta-
bility tests designed to measure the wear protection char-
acteristics; that is, to measure how the oils protect in-
ternal loaded engine components against excessive wear. The
engine is run at high speed under high loads. The first
measurement is the per cent increase in 40~C viscosity after
64 hours. It is surprising to note that formulation A had a
much lower viscosity change than did formulation B when it
is remembered that oligomer mixture B had a higher viscosity
index (indicating less change of viscosity with temperature)
than did oligomer mixture B ~see Table IV). What is also
surprising is -that formulation B required 6.47 quarts of oil
for the Se~uence IIID tests, whereas formulation A required
only 5.0 quarts. This result is contrary to what would be
expected from the volatility information derived from the
simulated distillation set out in Table V. It is particu-
larly surprising when it is realized that the 4 cs fluid of
this invention comprises only about 25% heavies. One skilled
in the art would expect the more volatile material ~A) to
cause any formulation made therefrom to require more oil.
However, as may be seen in Table VII, it is formulation B,
having the less volatile oligomer mixture, which has the
greater quantity requirements.
In the rest of the sequence IIID tests, the two
- 30 formulations were quite comparable. ~owever, formulation A
-33-
again gives better results in the Coordinating Research
Council L-38 test, which is a measure of bearing corrosion
by measuring the weight loss of the bearing. In the first
determination, formulation B failed the test with a weight
loss of 45.9 mg, though it passed on a second attempt with
39.5 mg loss. Formulation A caused a much lower weight
loss of 24.3 mg.
The Caterpillar 1~2 test is test measuring the
accumulation of deposits on diesel pistons, among other cri-
teria. Demerits are assigned in this test by the subjectiveopinion of a person approved by API (American Petroleum In-
stitute). Although formulation A performed poorer than
formulation B in the amount of top groove filling found, the
weighted total demeri-ts for both durations for formulation A
was much less than that for formulation B. These results
are further evidence of the surprisingly superior character-
istics of the oligomer mixtures made from only internal ole
fins and a promoted BF3 catalyst.
Many modifications may be macle in the method OI
this invention without departing fxom its scope which is de~
fined only by the appended claims. For example, it would be
expected that one skilled in the art could change the BF3
promoter, the temperature, pressure, modes of addition or
the olefin molecular weight in trying to maximize the con~
version or the oligomer properties.
-34-
;
