Note: Descriptions are shown in the official language in which they were submitted.
~ INSULATING OIL COMPOSIr~IONS
.
BACKGRO~ND OF THE INVENTION
.
1. Field of the__Invention
~` This invention relates t~ novel insulatin~ oil composi-
tions comprising a major amount of an insulating oil and a
minor amount of a product obtained as a result of a process
which comprises reacting benzene with ethylene in the pre-
sence of an alkylation catalyst to obtain a reaction mixture
containing largely unreacted benzene, ethylbenzene, poly-
ethylbenzenes, l,l-diphenylethane and heavier material,
separating at least benzene, ethylbenzene and polyethylben-
zenes from said reaction mixture and thereafter recovering
from said heavier material a fraction whose boiling points
fall within a temperature range of about 255 to about 420C.
as said product.
2. Description of the Prior Art
Insulating oils, for exàmple, transformer oils, are
required to have low power factors and high dielectric
strengths, and to be able to maintain thermal and oxidative
stability toward deyradation and oxidation and to possess
minimum tendency toward the formation of gas while in use.
See, for example, U.S. Patent No. 3,549,537 to Brewster et
al. Insulating oils composed largely of naphthenes and~or
highly-branched, non-cyclic, paraffins can be used satis-
factorily as transformer oils, for example, but unfortunately,they possess the tendency to produce gas during service.
SUMMARY OF THE INVENTION
.
We have found that the gassing characteristics of
insulating oils composed largely of naphthenes and/or highly-
branched, noncyclic paraffins can be greatly decreased bythe addition the`reto of a selected amount of a product ob-
tained as a result of a process which comprises reacting
benzene with ethylene in the presence of an alkylation catalyst
~b '
to obtain a reaction mixture containing largel~ unreac~ed
benzene, ethylbenzene, polyethylben~enesr l,1-diphenylethane
and heavier materlal, separating at least benzene, ethylbenzene
and polyethylbenzenes from said reaction mixture and there-
aEter recovering from said heavier material a fraction whoseboiling points fall within a temperature range of about 255
to about 420C. as said product.
sRIEF DESCRIPTION OF NOVEL INSULATING OIL COMPOSITIONS
The insulating oils used herein can be obtained from
any naphthenic and/or paraffinic origin. By "naphthenic and/
or paraffinic oils" we mean to include naturally-derived, or
synthetic, stocks containing largely one-ring structures,
such as cyclopentane and cyclohexane derivatives, two-ring
structures, such as decalin and dicyclohexyl derivatives,
three-, four-, and five-membered ring structures, which may
be part of the same or different molecule and their mixtures,
etc. The paraffinic oils are defined as being largely of
highly-branched, non-cyclic, compounds. A more useful conven-
tional definition is that developed by E. C. Lane and E. L.
Garton in the "Bureau of Mines ~eport of Investigations No.
3279", September, 1935, and reported in "Petroleum Refining
Processes" by M. M. Stephens and O. F. Spencer, 4th Edition,
The Pennsylvania State University Press, University Park,
Pa., 1958, page 38, in which classification is based on the
gravity of the first two distillation cuts. Typical naph-
thenic crudes include those from ~untingdon Beach, San
Joaquin, Coastal B-l, etc. Typical paraffinic crudes are the
Poza Rica, Kuwait, Grand Bay/Quarantine Bay, Ordovician
Crudes, etc. In addition these oils can be synthetic oils,
such as those obtained as the result of the oligomerization
of 1-olefins having from six to 14 carbon atoms, preferably
from eight to 12 carbon atoms, such as l-decene, mixtures of
l-decene and 1-octene, l-dodecene, etc., as described, for
example, in U.S. Patent No. 4,045,507 to Cupples et al.
Mixtures of naphthenic and paraffinic oils, including mixtures
of natural and s~nthetic oils, can also be used, for example,
in weight ratios of about 99:1 to about 1:99, preferably
, about 90:10 to about lQ:90~ In general the insulating oil
used herein can be defined in accordance with the parameters
: : :. .
.. , . - , :
~3~
,
set forth in Table I.
TABLE I
Preferred
Broad Ran~e Range
Specific Gravity, 60/60FØ75 to ~.91 0.79 to 0.91
tl5.5/15.5C.)
Viscosity, SUS:s (ASTM D-2161)
; (100F.. or 37.8C.) 40 to 70 50 to 70
(210F. or 98.9C.) .30 to 36.532 to 36.5
Viscosity, Xin: ~St
(100F. or 37.8C.) 4 to 13 6 to 13
(210F. or 98.9C.) 1.5 to 3.1 2 to 3.1
Pour Point, (ASTM D-97)
F. -120 to -40 -100 to -40
15 C. -80 to -40 -73 to -40
Flash Point, (ASTM D-92)
F. 293 to 500293 to 400
~. 140 to 260140 to 204
Weight Per Cent Total Paraffin*
Content 80 to 100 90 to 100
Weight Per Cent Aromatic
Content 0 to 20 0 to 10
Interfacial Tension, mN/m,
(ASTM D-971) 40 to 80 40 to 60
-
* Highly-branched, non-cyclic paraffins, highly-branched cyclic
paraffins and/or their mixtu~es.
The.product that is adaed to the above insulating oils
to reduce their gassing tendencies of such insulating oils
are defined in TJnited States Patent Nos. 4,111,~24 and
4,111,825.
Briefly, the product is obtained by reacting ben-
zene with ethylene to obtain a reaction mixture containing
largely unreacted benzene, ethyIbenzene, polyethylbenzenes,
l,l-diphenylethane and heavier material, separating at least
benzene, ethylbenzene, and polyethylbenzenes from said reaction
mixture and thereafter r~covering from said heavier material
the entire fraction, or any portion of said fraction, whose
boiling points at atmospheric pressure (ambient pressure)
fall wit~in a temperature range of about 255 to about 420C.,
preferably 260 to about 400C., most preferably about 268
to about 400~C. In case l,l-diphenyl ethane is also removed
from said heavier material the product that is added to the
above insulating oils is the entire fraction, or any portion
.. . . . .
353~
.~
-4-
of said fraction, whose boiling points at atmospheric pressure
fall within a temperature range of about 275 to about 420~C.,
preferably about 280 to about 400C.
The amounts of said procluct added to the insulating
oil to inhibit the gassing tendency thereof can be varied -
over a wide limit, but, in general, the amount present, based
on the weight of the final insulating composition, will be in
the range of about five to about 20 weight per cent, prefer-
ably about five to about 15 weic~ht per cent. Since the in-
sulating oil and said product are both hydrocarbons and
therefore completely miscible one in the other, mixing of the
two at ambient temperature and ambient pressure until a
homogeneous solution is obtained will suffice.
DESCRIPTION OF PREFERRED EMBODIMENTS
1'he following Table II compares the properties of the
naphthenic base oil employed herein with the ASTM D-3487
insulating oil specifications for Type I Oil. The naturally-
derived base oil (naphthenic) was obtained from Interprovincial
` Pipeline No. 1 and was a mixture of low sulfur, low pour point
~` 20 crudes. After conventional distillation, the fraction con-
sisting of a 50:50 mixture of light vacuum and heavy vacuum
oils (Gravity API 25) was subjected to hydrotreating follow-
ing the conditions in U.S. Patent No. 3,764,518. The purpose
of this treatment was to upgrade the product through hydro-
cracking, isomerization and saturation. After the first
stage hydrotreatment, the product was then subjected to a
second stage hydrotreatment following the conditions in
Canadian Patent No. 978,881, wherein the primary purpose of
such treatment is to saturate aromatic structures with hydro-
gen. The product from the two stage hydrotreatment has the
properties shown in Table II. The synthetic base oil was
prepared in accordance with the procedure of Example 1 of
U.S. Patent No. 4,045,507 of ~upples et al, employing l-decene
as feedstock. The product from this oligomerization, after
stripping off unreacted l-decene, indicated 53 per cent con-
version, and was found to contain 24 weight per cent dimer,
the remainder being the trimer, tetramer and pentamer of
, :
.. .. . ..
~3S~
l-decene. The total product was then passed over a commercial
nickel catalyst (NiO104T, 1/8-inch pellets having a surface
area of 125 square meters per gram) at 165C. and 600 pounds
per square inch gauge (41 kilograms per square centimeter)
of hydrogen pressure at a rate sufficient to effect stabiliza-
tion of the product through hydrogenation. Distillation
under vacuum afforded the synthetic base oil used herein, a
dimer fraction boiling in the temperature range of 160-
168C. at five millimeters of mercury.
TABLE II
ASTM D-3487,
Naturally-derived Synthetic Insulating Oil
Description Base Oil (Naph- Base Oil Specifications
or Test thenic) (ParaEfi~ic) Type I Oil
Gravity: API
(ASTM D-1298) 34 46.5 ___
Specific Gravity,
(ASTM-D941)
60/60F.
(15.5/15.5C.) 0.8550 0.7949 max 0.91
Viscosity, SUV: s
(ASTM D-2161)
37.8C. (100F~) 59.5 42.6 max 70
98.9C. (210CF.) 34.7 31.6 max 36.5
Viscosity, Kin: cSt
37.8C. (100F.) 10.17 5.06 max 13.0
98.9C. (210F.) 2.55 1.65 max 3.1
Interfacial Tension:
mN/M (ASTM D-971) 55 50 min 40
Flash, COC: F. (C.)
(ASTM D-92) 350 (177) 315 (157) min 293 (145)
Fire, COC: F. (C.)
(ASTM D-92) 370 (188) 345 (174) --~
Pour Point: F.(C.)
(ASTM D-97) -55(-48) below -100 (-73) max ~40 (-40)
Appearance (Visual) bright water white clear & bright
Color, (ASTM D-1500) L 0.5 L 0.5 max 0.5
Corrosive Sulfur,
(ASTM D-1275) Non-corrosive Non-corrosive Non-corrosive
Water: PPM
(ASTM D-1315) 24 15 max 35
Neutralization No.,
(ASTM D-974)
Total Acid No. < 0.03 < 0.03 max 0.03
, . ,: , - . ~ , :: .: , : . , : . : . : ,
6--
TABLE II '('con't'd.)
Naturally-derived Synthetic Insulating Oil
Descripkion Base Oil (Naph- Base Oil Specifications
or Test_ theni'c) '' __ ' ('Para'ff'inic) Type I'Oil
(ASTM D-611):
F. (C.) 204 (95) 215 (102) 145~172 (63-78)
Power Factor,
(ASTM D-924):
Per Cent
25C (77F ) 0 o652 o o52 max 0 05
Dielectric Strength:
~, Kv (ASTM D-877) 47 46 min 30
Oxidation Test,
(ASTM D-2440)
(0.075 Per Cent
DBPC*)'
72 Hour
Sludge: Per Cent 0.008 0 001 max 0 1
Total Acid No. 0.10 0 06 max 0 5
164 Hour
Sludge Per Cent 0 09 0 103 max 0 6
Rotary Bomb Oxida-
tion:
Min (0.075 Per Cent :'
DBPC)
(ASTM D-2112), 140C. 125 480~ --~
30 Analysis, Weight Per
Cent
Aromatics 0.4 0.0
Saturates 99.6 100 Per Cent
Branched
Isoparaffins
Mass Spec Analysis,
Weight Per Cent Alkanes 24.0 Average Mol.
Weight = 280
l-Ring
Cycloalkanes 27,3
2-Ring
Cycloalkanes 18.7
3-Ring
~cloalkanes 13.7
4-Ring
Cycloalkanes 12.0
5-Ring
Cycloalkanes 4.2
Aromatics 0.1
~3S~
--7--
TABLE II' (co;nt'd.)
ASTM D-3487,
Naturally-derived Synthetic Insulating Oil
Description Base Oil (naph-Base OilSpecifications
or Test thenic)''(Paxaffinic) T'ype I Oil
Gassing Tendency;
(ASTM D-2300),
mm /min
Procedure B,
80C.
50 Minutes Using
Hydrogen as
Saturant Gas -~38.5 +32.0 ---
'~ * 2,6-ditertiarybutyl-p-cresol
A product for adding to the naphthenic oil was pre~
pared as follows: Benzene and ethylene in a molar ratio of
9:1 were contacted in the liquid phase, while stirring, in a
reactor at a temperature of 130C. and a pressure of 70 pounds
per square inch gauge (4.9 kilograms per square centimeter)
in the presence of AlC13 catalyst over a period of one hour,
which was sufficient to convert all of the ethylene. The
AlC13 complex catalyst was prepared by dissolving AlC13 in a
polyethylbenzene cut from a previous rlm so that after the
addition the composition of the catalyst complex was as fol-
lows: 31.5 weight per cent AlC13, 7.0 weight per cent
benzene, 19.3 weight per cent ethylbenzene, 29.8 weight per
cent polyalkylated benzenes, 3.4 weight per cent l,l-diphenyl-
ethane and 9.0 weight per cent higher-boiling components.
The amount of AlC13 present in the catalyst mixture amounted
to 0.0034 parts by weight per one part by weight of ethyl-
i benzene produced. Also present in the catalyst was ethyl
chloride as promoter in an amount corresponding 0.0034 parts
by weight per one part by weight of ethylbenzene produced to
maintain a high catalyst efficiency. Analysis of the alkyla-
'~ 35 tion product showed the presence of 49.0 weight per cent
benzene, 32.9 weight per cent ethylbenzene, 17.5 weight per
cent of polyalkylated benzenes (6.0 weight per cent diethyl-
benzene, 2.7 weight per cent triethylbenzenes, 2.1 weight per
cent tetraethylbenzenes and 6.7 welght per cent other alkyl-
~40 benzenes), 0.1 weight per cent l,l-dipehnylethane and 0.4
weight per cent residue. The alkylation product was subjected
:
. ~,~ . -.- - . . . .
~L~3Si~
--8--
to distlllation to recover unreacted benzene, ethylbenzene,
polyalkylated benzenes and l,l-diphenylethane, and the
benzene and polyalkylated benzenes were recycled to the
reaction zone. The residue remaining was a dark, viscous,
high-boiling material, and was produced in an amount corres-
ponding to 0.012 parts for each part of ethylbenzene produced.
The residue so obtained was subjected to distillation to ob-
tain a cut having a boiling point at atmospheric pressure with-
in the temperature range of 275 to 400C. This cut was the
product added to the naphthenic oil and to the paraffinic oil
in a later example. The incorporation of the product in thenaphthenic oil was easily effected by physical blending,
since each is miscible in the other in all proportions. Two
blends were prepared, one containing 12 weight per cent of
the product from the residue (Blend No. 1) and the other 15
weight per cent (Blend No. 2). The results obtained are
tabulated below in Table III.
TAB E III
Blend Blend
Descri~ion or Test Nd. 1 No. 2
.. _ . ,
Gravity: API (ASTM D-1298) 31.4 30.5
Specific Gravity, (ASTM D-941)
60/60F. (15.5/15.5C.) 0.8697 0.8735
Viscosity, SUV: s (ASTM D-2161)
37.8C. (100F.) 55.4 54.9
98.9C. (210F.) 34.1 34.0
Viscosity, Kin: cSt
37.8C. (100F.) 8.99 8.87
98.9C. (210F.) 2.34 2.36
Interfacial Tension: mN/m
(ASTM D-971) 51 ___
Flash, COC: F. (C.) (ASTM D-92) 345 (174) -~~
Fire, COC: F. (C.) (ASTM D-92) 350 (177) --~
Pour Point: F. (C.) (ASTM D-97) -65 (-54) -65 (-54)
Appearance (Visual) bright bright
Color, ASTM D-1500 L 0.5 L 0.5
Corrosive Sulfur,
(ASTM D-1275) Non-corrosive ---
Water: PPM (ASTM D-1315) 14 ---
Neutralization No.,
(ASTM D-974)
Total Acid No. ~0.03 ---
~ 3s5~3~
TABLE III (cont'd.)
Blend Blend
Description or Test No. 1 No._2
Aniline Point,
(ASTM D-611): F (C.) 186 (85) ---
Power Factor,
~ASTM D-924): Per Cent
25C. (77F.) 0.002 ---
100C. (212F.) 0.065 ---
Dielectric Strength:
Kv (ASTM D-877;) 46 --
Oxidation Test,
(ASTM D-2440)
(0.075 Per Cent
DBPC*)
72 Hour
Sludge: Per Cent 0.002 0.001
Total Acid No. 0.21 0.21
164 Hour
Sludge: Per Cent 0.003 0.002
Total Acid No. 0.26 0.26
Rotary Bomb Oxidation:
Min (0.075 Per Cent
DBPC)
ASTM D-2112, 140C. 215 190
Analysis, Weight Per Cent
Aromatics 14 2 ---
Saturates 85 8 ---
Gassing Tendency;
(ASTM D-2300),
mm3/min
Procedure B, 80C.
50 Minutes Using
Hydrogen as
Saturant Gas -2.8 -11.3
* 2,6-ditertiarybutyl-p-cresol
The data in the above table clearly show the advan-
tages resulting from the claimed invention. The base oil
alone had a tendency to give off much gas. The mere addition
of a portion of the residue from the reaction of benzene with
ethylene to the base oil in fact not only greatly reduced
gassing tendency of the oil but resulted in a blend having
gas absorption properties. Note, too, the particularly sur-
prising fact that the addition of inherently unstable additive
to a base oil did not adversely affect the sludge and acid
number and that the number of minutes when such blends were
--10--
subjected to the rotary bomb oxidation tests was actually
extended ~rom 125 to at least 190. This is most unusual in
light of the data in Table IV, below, which shows that the
portion of the residue alone gave poor results when sub~ected
to the Oxidation Test ASTM D-2~0 and Rotary Bomb Oxidation
Test ASTM D-21120 Other data in Table III show that a com-
bination of base oil and residue from the reaction of benzene
with ethylene not only gives good oxidative stability and low
gassing tendencies, but that components in the mixture are
10 compatible with each other as physical properties show.
TABLE IV
Properties
Portion o~ Residue
Description or Test Adde'd' to Ba'se Oil
Specific Gravity, (ASTM D-941)
60/60F. (15.5/15.5C.) 0.920
Boiling Point, C. 280-400
Molecular Weight 240
Viscosity, Kin: cSt (ASTM D-2161)
100F. (37.8C.) 6.35
210F. (98.9C.) 1.80
Flash Point COC: F. (C.) (ASTM D-92) 310 (154)
Fire Point, F. (C.) (ASTM D-92) 333 (167)
Pour Point: F. (C.) (ASTM D-97) -65 (-54)
Refractive Index, nD 1.5555
Interfacial Tension, mN/m ~ASTM D-971) 42
Color, (ASTM D-1500) L 0.05
Water: PPM (ASTM D-1315) 57
Neutralization No., (ASTM D-974)
Total Acid No. 0.03
Aniline Point, F. (C.)(ASTM D-611) 16.7 (-8.5)
Dielectric Constant, (ASTM D-924) 2.5
Dielectric Strength, kV: (ASTM D-877) 50+
Power Factor, Per Cent: (ASTM D-924)
77F. ~25C~) 0.005
212F. (100C.) 0.26
Rotary Bomb Oxidation, (Min ~STM D-2112)
0.075 Per Cent DBPC* 77
Oxidation Test, (ASTM D-2440)
(0.075 Per Cent DBPC)
72 Hour
Sludge: Per Cent 21.0
Total Acid No. 10.2 ~`
' '' ~' ' ' ' " ' , ' . ~ ' C; , ' .. '; ,-. , : ~"
: ' . , ' ' ':, ~
~3~
TABLE IV (cont'd.)
Properties
Portioll of Residue
5 Description or Test ~dded'to B'ase Ol'l
164 Hour
Sludge: Per Cent 40.0
Total Acid No. 10.4
* 2,6-ditertiarybutyl-p-cresol
Additional tests were carried out wherein the residue
added to the naphthenic oil was also added to the synthetic
oil defined above. For this purpose a mixture containing 90
weight per cent paraffin base oil and 10 weight per cen-t of
residue was used (Blend III). The results obtained are set
forth in Table V below.
TABLE V
Description or Test B'lend III
Gravity: API (ASTM D-1298) 42.2
Specific Gravity,
60/60F. (15.5/15.5C.) (ASTM D-941) 0.8146
Viscosity, SW: s (ASTM D-2161~
37.8C. (100F.) 42.7
98.9C. (210F.) 31.5
Viscosity, Kin: cSt
37.8C. (100F.) 5.10
98.9C. (210F.) 1.66
Interfacial Tension: mN/m (ASTM D-971) 43
Flash, COC: F. (C.) (ASTM D-92) 300 (149)
Fire, COC: F. (C.) (ASTM D-92) 330 (165)
Pour Point: F. (C.) (ASTM D-97) below -65 (-54)
Appearance (Visual) bright
Color (ASTM D-1500) L.05 ;
Corrosive Sulfur ~'
(ASTM D-1275) Non-corrosive
Water: PPM (ASTM D-13I5) 48
Neutralization No.,
(ASTM D-974) ~'
Total Acid No. ~0.03
';:
`:
~ ~5~9~
-12-
l'ABLE V (cont'd.)
on or Test Blend III
Aniline Point,
(ASTM D-611): F. (C.) 201 (94)
Power Factor,
(ASTM D-924): Per Cent
25C. (77F.) 0.006
100C. (212F.) 0.045
Dielectric Strength:
o Kv (ASTM D~877) 44
Oxidation Test,
(ASTM D-2440)
(0.30 Per Cent DBPC*)
72 Hour
Sludge: Per Cent 0.002
Total Acid No. 0.21
- 164 Hour
Sludge: Per Cent 0.002
Total Acid No. 0.26
Rotary Bomb Oxidation-
Min (0.30 Per Cent DBPC)
(ASTM D-2112), 140C. 300+
Gassing Tendency: (ASTM D-2300),
mm /min
Procedure B, 80C.
50 Minutes Using Hydrogen as
Saturant Gas -10.2
* 2,6-ditertiarybutyl-p-cresol
The data in Table V show that a blend of residue
from the reaction of benzene with ethylene and a paraffinic
base oil has excellent oxidative stability, very low gassing
tendency, and that the two fluids in a mixture are compatible
with each other as physical properties show.
Obviously, many modifications and variations of the
invention, as hereinabove set forth, can be made without de-
parting from the spirit and scope thereof, and therefore only
such limitations should be imposed as are indica-ted in the
appended claims.