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Патент USA US3070646

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Dec. 25, 1962
J. A. KIERAS
3?7??36
PROCESS FOR THE PREPARATION OF POSITION ISOMERS QF' C's TO
C35 MONOCHLQRO STRAIGHT-CHAIN PARAFF INS
-
Filed Nov. 25, 1959
WEIGHT
O
2
PER
4
6
CENT
GHLORINE
8
l2
IO
l4
l6
I820
|
00
IO
20
3O
,CUMULATIVE
4O
50 6O
MIDv PER
7O 8O 90 I00
GENT POINT
JOSEPH A. K! ERAS
INVENTOR.
BY
..
5M
ATTORNEY
'
United States Patent O?lice
1
' 3,070,636
Patented Dec. 25, 1962
2
such as the synthetic Fischer-Tropsch waxes and the like. .
3,070,636
In general, petroleum para?in wax fractions melting be
PROCESS FOR THE PREPARATION OF POSITION
ISOMERS ’0F
.
C18
T0
C35
tween 100° F. and 150° F. are suitable as well as the,
MONOCHLORO
higher melting synthetic Waxes. The para?in wax fraction
STRAIGHT-CHAlN PARAFFINS
is fractionally distilled at subatmospheric pressures pref- .
erably at a pressure of from 1 to 10 mm. of mercury to
produce a plurality of narrow boiling range fractions.‘ A
Joseph A. Kieras, Lincoln University, Pa., assignor to
The Atlantic Re?ning Company, Philadelphia, Pa., a
corporation of Pennsylvania
'
fraction containing a major amount of the desired paraffin
Filed Nov. 25, 1959, Ser. No. 855,303
hydrocarbon is selected (Cu), i.e., containing “n” car
4 Claims. (Cl. 260-660)
10 bon atoms, wherein n is an integer from 18 to 35. This
This invention relates to a process for the preparation
in the C18 to C35 range and, in particular, it relates to a
fraction, in addition to containing the desired straight
chain para?in as the major component, will also contain
minor amounts of higher and lower molecular weight
process for the preparation and separation of the in
straight-chain paraf?ns together with isopara?ins and
of position isomers of monochloro straight-chain paraf?ns
dividual position isomers of a single C18 to C35 mono 15 cyclopara?ins in the same molecular weight range. This
chloro straight-chain para?in.
fraction is redistilled at sub-atmospheric pressures again
Heretofore, it was believed that the individual isomers
of a single paraffin in the C18 to C35 range could not be
preferably in the 1 to 10 mm. of mercury range to pro—
duce an additional number of narrow boiling range frac
prepared except by exceedingly complex methods of
tions. The intermediate fractions, the so-called heart
synthesis and, consequently, only a very few of these iso 20 cut fractions, .from this distillation are selected since they I '
mers were synthesized. The production of the individual
contain a major amount of the desired sgraight-chain
position isomers of a single monochloro straight-chain
parat?n hydrocarbon with very minor amounts of lower
parat?n in the range of 18 to 35 carbon atoms has long
molecular weight straight-chain para?ins, isoparaf?ns,
been desired since these alkyl chlorides can be used to
and cyelopara?ins, but no compounds of higher molecu
produce the corresponding primary and secondary alco 25 lar weight. These intermediate fractions are dissolved
in a wax solvent and fractionally crystallized from the
hols. Furthermore, these alkyl chlorides can be used to
alkylate aromatics and the resulting alkyl aromatics when
solvent to produce a plurality of narrow melting range
sulfonated give oil-soluble detergent compounds having
fractions. The ?rst fraction constituting the highest
unique and controllable characteristics and properties
melting point material is selected since it contains the
when employed as additives in motor oils.
30
A process now has been found whereby it is possible
to prepare the position isomers of a high molecular
weight straight-chain paraf?n byt?rst providing a paraflin
wax fraction containing a critical major amount of a
single straight-chain paraflin, monochlorinating this wax ‘
fraction, dissolving the chlorinated wax fraction in a
solvent and fractionally crystallizing from the solvent a
plurality of fractions containing respectively the non
chlorinated paratiins and the position isomers of the de
sired stright-chain para?in, leaving the higher chlorinated
parafiins in solution.
it is therefore an object of this invention to provide a
process for the preparation of position isomers of mono
chloro straight-chain para?ins in the C18 to C35 range.
It is another object of this invention to provide a proc
ess for the preparation of position isomers of monochloro
straight—chain p-"tratllns in the C13 to C35 range from
petroleum parallin wax fractions.
Other objects will be apparent from the description of
the invention and the claims that follow.
In accordance with this invention a para?’in wax frac
tion containing a critical major amount of a single
straight~chain paraf?n is utilized as the starting material
' which single straight-chain para?in constituting the
major component of the wax fraction must have a carbon
atom content in the range of from 18 to 35 carbon atoms.
This paratlin wax fraction is monochlorinated to give a
major quantity of the desired straight-chain paraf?n with
only very minor quantities of slightly lower molecular
weight straight-chain para?‘ins but no isopara?ins or cyclo
para?ins. If desired, this fraction may be redissolved in
fresh solvent'and recrystallized to produce a paraf?nic
fraction of high purity. In general, such a fraction will
contain at least 97 weight percent of the desired straight
chain para?in (C,,) with the remainder of the fraction
being straight-chain para?ins differing by one or two car- .
bon atoms from the number of carbon atoms in the de
sired major component (Cn_2 to CH2) wherein n is an
integer from 18 to 35.
The solvents which may be used include any of the
conventional wax solvents such as methyl ethyl ketone,
acetone-benzene. methyl ethyl ketone-benzene-toluene,
ethylene dichloride, ethyl acetate, low molecular weight
para?ins including liqui?ed normally gaseous paraf?ns
and the like. Since these solvents do not have equal
solvent power for dissolving waxes the ratio of solvent to
wax may be varied depending upon the solvent used and
the molecular weight of the wax fraction which it is de
sired to obtain. This ratio, like the solvent employed, .
is not critical and, in general, good results are obtained
when the solvent to wax ratio ranges between 5:1 and
15:1.
It has been found that the purity of the wax fraction
starting material is extremely critical. If the major com
ponent is present in an amount less than about 97 Weight
percent, or if the straight-chain para?in hydrocarbons
product containing unrcacted paratlin, essentially mono
chlorinated para?in and di- and polychlorinated para?in
present in minor amounts differ by more than about 2'
'in accordance with the principles of statistical distribution 60 carbon atoms from the number of carbon atoms in the
of the chlorine.
The chlorinated product is dissolved in a solvent pro
portion of a wax solvent which does not contain halogen
and thereafter the solution is chilled in successive steps
to produce by crystallization a plurality of fractions con
major component, it is not possible to produce a chlori
nated product from which the individual position isomers
of the monochloro straight-chain paratlin can be sep
arated.
Instead there is obtained a mixture which cannot -
‘be resolved by the method of this invention.
Alternatively, the desired high purity wax fraction start~
ing material may be produced by dissolving the commer
taining respectively the unreacted paraffin and the in
dividual position isomers of the monochlorinated para?in
cial wax in a solvent proportion, i.e., an amount of solvent
leaving the di- and polychlorinated para?ins in solution
although they may be separated if desired.
sufficient to provide the desired solvent to wax ratio, of a
The paraf?n wax fraction is preferably produced from 70 wax solvent and fractionally crystallizing a plurality of
commercial grade petroleum parat?n waxes although,
fractions from the solvent. The fraction containing a
of course, any source of paraffin wax may be employed
major proportion of the desired straight-chain paraf?n hy
8,070,686
drocarbon is selected and preferably this fraction is re
dissolved in fresh solvent and recrystallized to produce a
more highly puri?ed fraction essentially free of isoparaf
?ns and cycloparafiins but containing straight-chain
paraffins both of higher and lower molecular weight as
compared with the molecular weight of the desired
4
amount and the fractions should be of approximately
equal weight since the chlorination will produce approxi~
mately equal quantities of the isomers most easily formed.
It is believed that the isomers most easily formed ‘are
those wherein the chlorine is substituted for hydrogen on
the carbons near the end of the carbon chain of the par
af?n molecule. Finally, only the di- and polychlorinated
products remain in the solution. If desired, these may be
removed as the last crystalline fractions, which fractions
a fraction containing the desired straight~chain para?in
hydrocarbon in a major quantity in excess of 97 weight 10 need not be separated by at least 3“ F. to 5° F. in melting
point or be of equal weight since they are not the desired
percent with only minor amounts of straight-chain par‘
fractions.
afiins differing by at most 2 carbon atoms in the molecule
The ?rst fractional crystallization can be used to pro
from the number of carbon atoms in the desired straight
duce
isomer fractions in each of which a particular mono
chain paraffin major component.
chloro paraf?n position isomer predominates admixed
The paraf?nic wax fraction containing the critical
with minor amounts of the other position isomers of the
amount of straight-chain paraf?n is monochlorinated in
straight-chain paraffin. This puri?ed fraction is frac
tionally distilled at sub-atmospheric pressure to produce
desired monochloro Cn paraffin and trace amounts of the
Cn_2 to CH2 monochloro paraf?ns. Each of these frac
tions may be recrystallized several times if desired to
temperatures may be employed. Likewise, if desired, liq 20 produce extremely pure fractions, each containing a single
accordance with conventional practices. Thus, gaseous
chlorine may be used at temperatures ranging from about
160° F. to 250° F. although somewhat higher or lower
uid chlorine may be utilized either alone or with a suitable
solvent at somewhat lower temperatures than those em
ployed with gaseous chlorine to produce the desired
chlorinated product. The amount of chlorine employed
and the length of time of the chlorination reaction is ad
justed so that there is produced a monochlorinated prod
net. It will be understood that monochlorination refers
to an average of one chlorine atom per molecule of par
a?‘in although portions of the product will contain two
position isomer of the Cu monochloro paraffin.
In order to demonstrate a speci?c embodiment of the
invention a ISO-gallon sample of a commercial petroleum
paraffin wax having a melting point of 132° F. and a
composition shown in Table I was fractionally distilled at
2 mm. of mercury pressure to produce 44 cuts of approxi'
mately 3 gallons each and a bottoms fraction. The 16th
fraction was selected, melting point 126.6“ F., since it
contained predominantly C25 straight-chain para?in. The
or more atoms of chlorine. A large portion of the prod 30 approximate composition of this fraction is shown in
Table II.
uct, however, will contain one atom of chlorine per mole
Table I
cule of para?in. It has been found preferable that the
chlorination be regulated so that on the average one atom
of chlorine is substituted for one atom of hydrogen in
each molecule of the para?in since excess chlorine lowers 35
Straight:
Carbon content
chain
paraffin
Cyclo
Iso
paraffin parat?n
the yield of the desired monochloro isomers.
Another convenient method of controlling the chlorina
tion reaction is to measure the increase in weight of the
paraf?n being chlorinated as the chlorinating proceeds
and, when the increase in weight corresponds to a mono
chlorinated product based on the calculated weight for
such product, the reaction is discontinued.
The chlorinated product is dissolved in a solvent of the
type that is used for dissolving wax with the exception
that wax solvents which contain halogens should be
avoided since these have too great a solvent power for the
chlorinated parat?ns and home do not give clean crystal
lization separations. Solvents which may be employed
include methyl ethyl ketone, ethyl acetate, acetone, iso
octane, normal heptane, liqui?ed propane, and the like. 50
The particular solvent employed is not a critical feature
of the invention provided that such solvent does not have
such a strong solvent power for the chlorinated para?ins
that they cannot be crystallized therefrom by fractional
crystallization methods. Moreover, since these solvents 55
Carbon content
Cyclo
paraffin parallln
do not have equal solvent power for the chlorinated com
pounds, the ratio of solvent to chlorinated product which
should be used will depend on the particular solvent and
the molecular weight of the chlorinated product. In gen
eral, however, a solvent to chlorinated product ratio of
from 5:1 to 15:1 has been found to be completely satis
factory.
The solution of chlorinated product is chilled in a series
of steps to produce a plurality of fractions. The ?rst
PZ'HWNE"macwo
This 16th fraction was redistilled at 2 mm. of mercury’
pressure into 10 fractions of approximately equal weight.
fractions separated, i.e., those at the higher crystallization 65 Fractions 4 to 8 inclusive, the intermediate fractions,
weighing 2376 grams were selected and dissolved by heat
temperatures, are the unreacted paraf?ns containing small
ing to about 140° F. in 7 gallons of ethyl acetate, an ap
proximately 9:l volume ratio of solvent to wax.
The solution was cooled to 94° F. and crystallized at
As the crystallization temperatures are lowered, the next
fractions to separate are the monochlorinated para?ins. 70 this temperature. The ?rst wax fraction recovered hav
amounts of chlorinated paraffins since these fractions have
higher melting points than the monochlorinated para?ins.
These monochlorinated fractions should be of approxi
mately equal weight and separated in melting point by
from at least 3° F. to 5“ F. The melting points of the
fractions should be separated by at least 3° F. to 5° F.
ing a melting point of 128.2° F. and weighing 1499 grams
was redissolved in fresh ethyl acetate with a solvent to
wax ratio of about 15:1 and recrystallized at 70° F. to
obtain a fraction containing 97.6 weight percent C25
since the isomers differ in melting point by about this 76 straight~chain paraffin, 1.7 weight percent C24 straight
3,070,636
5
chain paraf?n, and 0.7 weight percent C23 straight-chain
and curve C is the plot of
paraf?n with no isopara?ins or cyclopara?ins.
A IOU-gram sample of this wax fraction was chlori
nated with chlorine gas at 220° F. to 240° F. until the
weight of the sample had increased to approximately 111
grams. By theory, if the Czs'paraf?n were monochlori
nated the weight of the 100-gram sample would have in- I
vs. the refractive index.
rectly with the weight percent of the chlorine in accord- ‘
ance with well-known theoretical considerations, namely,
that the refraction of light is an additive property de
creased to 110 grams, so a slight excess of chlorine was
pendent upon the composition of the compound and de
employed. The exact quantity of chlorine used is not
extremely critical, since there will always be some wax
e weight percent chlorine
It will be seen from the data in Table III as illus-i'
tnatcd in the drawing that the refractive index varies 'di
10
pendent only to a small extent on the structural arrange
ment of the atoms within the molecule.
Since in the,
not chlorinated and some wax di- and polychlorinated.
instant situation the chlorine isomers are structurally >
The amount of chlorine used should be adjusted, however,
very similar, the refractive index is a function solely of
the number of chlorine atoms substituted in the mole
cule. This is demonstrated by the fact that fractions 5,
6, 7, and 8 which contain an amount of chlorine corre
sponding approximately to the theoretical amount for
monochlorin'ation have approximately the same refrac
tive indices as shown by the plateau in curve B. These
monochlorinated fractions, however, are shown to be
to give approximately a theoretical monochlorinated
product since, if a large excess is used, little or no mono
chlorinated parat?ns are produced and polychlorinated
non-separable mixtures are produced instead. Thus, the
objects of the invention are defeated.
'
A lOO-gram sample of the chlorinated product (melting
point 103.8° F.) was dissolved by heating to about 135°
F. in 1000 ml. of ethyl acetate. The solution was cooled 20 different isomers by their large spread in melting point
illustrated by the steep slope of curve A for the portion
to 78.5" F. to produce the ?rst crystalline fraction which
of the curve encompassing these fractions.
was separated from the solution by ?ltration. The crys—
Fractions 1, 2, 3, and 4 which have nearly the same
tals were washed separately with cold ethyl acetate. The
melting point are composed primarily of unreacted par- '‘
dried crystals weighed 14.5 grams and, when the wash
solution was evaporated, an additional 3.0 grams of prod 25 a?in with small amounts of chlorinated paraffin. Frac
tion 9 and the residue are composed of di- and poly
uct was obtained. The melting point, refractive index
chlorinlated para?‘ins predominantly. Thus, these data
(nD8°° 0') and chlorine content of the 14.5-gram fraction
demonstrate that it is possible to separate the unreacted
were determined. These results are set forth in Table III.
material, the monochlorinated product, and the poly
The ?ltrate was cooled to a temperature of 76° F. and
a second fraction of crystals separated by ?ltration. This 30 chlorinated product and, moreover, it is possible to sepa
rate the monochlorinated material into. fractions having
‘fraction vamounted to 3.5 grams and its melting point, re
different structures as shown by their differences in melt
fractive index and percent chlorine determined, all of
ing point which structures are the position isomers.
which art set forth in Table III. These crystals were also
I claim:
washed and the wash solution evaporated to recover an
1. A process for the preparation of straight-chain iso
35
additional 2.5 grams of crystals.
meric monochloroparaf?ns in the Cu; to C35 range, which .
The cumulative mid weight percent point was calcu
comprises monochlorinating a straight-chain parat?nic
lated for each fraction. This was calculated by adding
wax fraction containing at least 97 weight percent of
the weight of the preceding fractions together with the
a single straight-chain para?in (C,,) as the major com
weight of the preceding wash recoveries and 1/2 of the
weight of the fraction being calculated. Thus, the cumu 40 ponent and as minor components straight-chain paraf?ns
differing by not more than two carbon atoms per. mole
lative mid weight percent point for fraction No. 2 was
cule from the major component (Cn_2 to CH2) wherein
determined by adding 14.5, 3.0, and 1A of the weight of
n is an integer from 18 to 35, to produce a chlorinated
fraction No. 2, i.e., 1/: of 3.5 or 1.75 grams, giving a total
product, dissolving the chlorinated product in a solvent
of 19.25 grams. The cumulative mid weight percent point
for fraction No. 3 was found by adding the weight of frac 45 proportion of a halogen-free wax solvent and separating
from the solution of the chlorinated product by crystalli
tion Nos. 1 and 2 (18.0 grams), wash recoveries of frac
zation essentially unreacted paraf?ns and a plurality of
tion Nos. 1 and 2 (5.5 grams) and 1/2 of fraction No. 3
approximately equal weight fractious differing in melt~
(2.75 grams) which equals 26.25 grams. The cumulative
ing point by at least 3° F. to 5° F., said fractions com
mid weight percent point was calculated in the same man
ner for each fraction. The crystallization temperature, 50 prising the straight-chain isomers of the monochloro
straight-chain Cn paraffin.
weight of the fractions, weight of the wash recovery,
2. A process for the preparation of straight-chain iso
cumulative mid weight percent point, melting point of the
meric monochloro para?ins in the C18 to C35 range,
fractions, refractive index of the fractions, and weight
which comprises reacting a straight-chain para?‘inic wax
percent chlorine of the fractions are set forth in com
55 fraction containing at least 97 weight percent of a single
plete detail in Table III.
Table III
Fraction
number
Crystallization
tempera-
Weight of
traction,
grams
78. 5
76.0
62. 0
42.0
14. 5
3. 5
5. 5
4.0
3.0
2. 5
2. 5
1.0
7.25
19. 25
26. 25
33. 50
127. 6
127. 4
126. 9
124. 2
5.0
' 0. 25
30. 00
107. 0
1. 43442
8. 70
5. 5
9. 0
7. 5
6. 5
1.0
2.0
2. 5
0.5
44. 50
52. 75
63. 00
72.50
95.0
72. 5
51.0
45. 5
1. 43612
1. 43708
1. 43607
1. 43988
10.20
11.50
11. 80
14.00
87. 75
0. 0
1. 45064
21. 90
ture, ° F.
26.0 Y
5
12.0
—12. 0
—24. 0
—52. 0
Residue ........................ _.
Weight of Cumulative
wash
mid weight,
recovery,
percent
grams
23. 0 .......... -.
point
Melting
oint of
raction,
In the drawing, the data ‘set forth in Table III are
plotted and smooth curves drawn therethrough. Curve
A is the plot of melting point of the fractions vs. the
cumulative mid percent point, curve B is the plot of
the refractive index vs. the cumulative mid percent point, 75
° F.
Refractive Weight
in ‘ex,
percent
m8“ chlorine in
of traction
1. 42636
1. 4%68
1. 42694
1. 42858
fraction
0.02
0.86
1. 10
2.80
straight-chain para?in (CD) as the major component and a
as minor components straight-chain para?ins differing by
not more than 2 carbon atoms per molecule from the
major component (C,,_3 to CH2) wherein n is an
integer from 18 to 35 with an amount of chlorine such
3,070,636
8
4. A process for the preparation of straight-chain iso
meric monochloro para?ins in the C18 to C35 range,
which comprises reacting a straight-chain para?inic wax
that an average of one atom of chlorine is substituted
for one atom of hydrogen in each molecule of the par
a?in thus producing a chlorinated product, dissolving the
chlorinated product in a solvent proportion of a halogen
fraction containing at least 97 weight percent of a
single straight-chain parat?n (Cn) as the major com
free wax solvent and separating from the solution of the
chlorinated product by crystallization essentially unre
ponent and as minor components straight-chain paraf?ns
acted paral?ns and a plurality of approximately equal
weight fractions differing in melting point by at least 3°
F. to 5° F., said fractions comprising ‘the straight-chain
cule from the major component (CH4 to CH2) where
isomers of the monochloro straight-chain Cx1 paraf?n.
differing by not more than 2 carbon atoms per mole
in n is an integer from 18 to 35 with an amount of chlo
10 rine such that an average of one atom of chlorine is sub
stituted for one atom of hydrogen in each molecule of
3. A process for the preparation of straight-chain iso~
meric monochloro para?‘ins in the C18 to C35 range,
which comprises monochlon'nating a straight-chain par
the para?in thus producing a chlorinated product, dis
solving the chlorinated product in from 5 to 15 volumes
of ethyl acetate per volume of chlorinated product and
separating from the ethyl acetate solution of the chlo
af?nic wax fraction containing at least 97 weight per—
cent of a single straight~chain para?in (Cu) as the major
component and as minor componentsvstraight-ch-ain par
rinated product by crystallization essentially unreacted
paraf?ns and a plurality of approximately equal weight
af‘?ns di?ering by not more than two carbon atoms per
fractions differing in melting point by at least 3° F. to 5°
molecule from the major component (CB4 to CH2),
F., said fractions containing the straight-chain isomers of
wherein n is an integer from 18 to 35, to produce a
the monochloro straight-chain Cn paraffin.
chlorinated product, dissolving the chlorinated product in
from 5 to 15 volumes of ethyl acetate per volume of
_ chlorinated product and separating from the ethyl acetate
References Cited in the ?le of this patent
UNITED STATES PATENTS
solution of the chlorinated product by crystallization es
sentially unreacted paraf?ns and a plurality of approxi
mately equal weight fractions differing in melting point
2,189,924
25
FOREIGN PATENTS
by at least 3° F. to 5° F., said fractions containing the
straight-chain isomers of the monochloro straight-chain
Cn paratlin.
Pier et a]. ___________ __ Feb. 13, 1940
650,273
785,969
Great Britain ________ .._. Feb. 21, 1951
Great Britain ________ .__ Nov. 6, 1957
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