Document zo9YoqL4mRnyyyyND4eexGgxB
United States Patent i>9
Nislilmalsu cl al.
C
mi 3,959,162 (45] May 25, 1976
154] INSULATING OIL
(75) Inventors: Mincakl Nishimatsti, Kyoto;
Sadayoshi Mukai, Katano; Kaname Ishida, Kyoto, all of Japan
[73] Assignee: Nissln Electric Co., Ltd., Kyoto,
Japan
'
[22] Filed: Aug. 2, 1974
[2I] Appl No : 494,342
OTHER PUBLICATIONS
Chemical Abstracts, Vol. 77, Col. 77638m. Chemical Abstracts, Vol. 76. Col. 86589c.
Primary Examiner--John D. Welsh Attorney, Agent, or Firm--Christensen, O'Connor, Garrison St Havclka
(30) Foreign Application Priority Data Aug. 20, 1973 Japan........................... 4S-93III
(52} US. Cl................................... 252/63.7; 252/64; 336/94; 252/78; 174/17 LF; 252/49.8
|5I) Int. Cl.......................II0IB 3/18; HOIF 27/02 (58) Field of Search............ 260/966; 252/63.7, 64,
252/49.8, 78,79; 336/94; 174/17 LF
|56) 1,721,295
References Cited UNITED STATES PATENTS 7/1929 Docrflinger......................... 252/63.7
|57] ABSTRACT
An insulating oil for use in electrical devices, compris ing a mixture of trixylcnylphosphatc and 10% to 40% by volume of insulating oil having a viscosity of $ cp to 15 cp at 30*C and selected from the group consist ing of mineral oil, alkylbcnzenc, alkylnaphthalenc, diallylalkane, 2-diphcnylmcthylether, 2-diphcnylisopropylcthcr, paraffin hydrocarbon oil and naph'thcnc hydrocarbon oil.
11 Claims, No Drawings
M0NS 060420
Jfs
3
4
3.959.162
12
selected from the following group: mineral oil (to he
INSULATING OIL
referred to as MO), alkylbcnzcnc (to be referred to as
BACKGROUND OP THE INVENT ION
Afi), alkylnaphlhalcnc (to be referred to as AN), diullylalkanc (to be referred to as DAA), paraffin hydro-
This invention relates to insulating oil compositions 5 carbon oil (to be referred to as PO), naphthene hydro
used in oil-filled or oil-immersed electrical devices.
carbon oil (lo be referred to as NO), 2-diphcnylme-
Insulating oil is widely used in various types of elec thylcthcr (to be referred to as DME). 2-diphcnyliso-
trical devices such as power cables, transformers, ca propylcther (to be referred to as DPE). etc.
pacitors and so on. It has hithcrcto been customary to
use mineral oil or diphenyl chloride as the Insulating oil 10 DETAILED DESCRIPTION OF I HR INVENTION
for such electrical devices. Recently, such electrical
AND THE PREFERRED EMBODIMENTS
devices tend to become of greater capacity and more
The combustibility and electrical characteristics of
capable of withstanding higher voltages, so that the TXP and the above-mentioned insulating oils arc given
insulating oil used in them must have characteristics to in TABLE 1.
TABLE 1
Charade riitka
fiuufatirtf oil txp MO AB AN OAA fO NO DME DPE
ViKOtily Up)
tat JOT)
Specific Haiti gravity point Comhuttihilily (at 1ST i <T>
10)
V 10 t 9 9 IJ 14.7
1 12 3)0 Incombuttibk 017 1)2 Comtiuiiihlr 0.11 136 096 140 096 ISO 016 >32 Oil 136 0 91 134 0.91 1)9
Charerteritliea
Dfcfectrk conttani (at SOT)
Ok fectrfc loa* tangent
<) tat SOT)
Vofumr reiiflivtly tn-em)
Vuibk |at
|tncriin| voita| (kV/mml
(mutating off
TXP MO AB AN DAA PO NO DME DPE
3*9
0.21
I.OxtO"
37 0
2.20
0010
1 S*I0'
470
2 20
ooto
2 Ox 10'*
320
247
0.010
3 5X10"
6S0
291
0010
1 0X10"
70 0
230
ooto
2.5x10**
40 0
2.21
0 010
2 0X10"
43 0
3.10
0.06
1 0X10"
6* S
4.IS
0.06
10*10"
67.0
meet the tendney.
Mineral oil atone, however, is combustible and infe
The physical properties such as viscosity, etc, as well
rior in such electrical characteristics as dielectric con is the electrical characteristics such as dielectric con-
stant and visible gas generating voltage. While diphenyl 45 stanl, visible gas generating voltage, etc of mixtures
chloride is incombustible and superior tn the above- comprising TXP and 10%, 20%, 30% by volume, re
mentioned characteristics, it is very toxic to the human spcctivcly, of one or two of the above insulating oils are
body so that the use of this compound is undesirable given In TABLES 2 through 12 in comparison with
from the view point of environmental pollution.
those of the mixtures comprising TXP and 45% and
Accordingly, the primary object of the invention is to 50 50% of one or (wo of those insulating oils.
provide an insulating oil composition which has good
In TABLE 2 the material tested comprises a mixture
characteristics as such oil.
of TXP and MO; in TABLE 3 it comprises a mixture of
Another object of the invention is to provide an insu TXP and AB;in TABLE 4 it comprisesa mixture of
lating oil composition which is superior to mineral oil in TXP and AN;in TABLE 5 it comprisesa mixture of
electrical characteristics such as dielectric constant, $5 TXP and DAA; in TABLE 6 it comprises a mixture of
visible gas generating voltage, etc.
TXP and PO;in TABLE 7 it comprisesa mixture of
Another object of the invention is to provide such an TXP and NO;in TABLE 8 it comprisesa mixture of
insulating oil composition as aforesaid which is incum- TXP and DME; in TABLE 9 it comprises a mixture of
bustiblc and has no toxicity to the human as well as TXP and DPE; in TABLE 10 it comprises a mixture of
animal life.
60 TXP, MO and AN; in T ABLE 11 it comprises a mixture
In accordance with the invention there is provided an of TXP, AN and DMF; and in TABLE 12 it comprises
insulating oil composition which comprises a mixture a mixture of TXP, MO and DMF..
of trixylcnylphosphalc (which will be referred to as
In the above TABLES one or two of the insulating
TXP) and an insulating oil having a viscosity of 5 to 15 oils are mixed with TXP. If three or more of the insulut-
ccntipoiscs (which will be abbreviated to cp) at 30C, 65 jng oils ^rc mixed with TXP, similar results arc ob
the amount of of the latter oil to be mixed with TXP tained to those obtained from the mixture of I'XP and
being 10% to 40% by volume of the mixture. The insu one or two of the insulating oils, as will be obvious to
lating oil which has a viscosity of 5 cp to IS cp can be those skilled in (lie an.
M0NS 060421
3,959,162
34
The flash point has been measured in the following to the sleeve for three seconds, after which the flame is
manner, 't he oil whose flash point is to be tested is put moved away from the sleeve so as to see if (here is a
in a pot, which is tightly closed The oil is slowly heated burning flume on the sleeve. In the TABLES, the word
while it is being stirred at a constant speed. A thermom ''combustible" means that there was a burning flame
eter is provided to measure the temperature of-the oil 5 under the above condition while the word ` incombusti
In the pot. When the oil approaches the expected flash ble" means that there was no such burning flame.
point, the Min ing is stopped whenever the temperature
7'hc visible gas generating voltage has been measured
rises a predetermined number of degrees, say, 2C, in the following manner. A voltage is applied to I sheet
wheteupon a small window provided in the lid of the of paper immersed with the insulating oil to be tested
pot is opened so that a 7 mm long flame is put in the pot 1 and tlic voltage is increased until visible gas is gener
so as to see if the vapor of the oil is ignited. The lowest ated. The level of the impressed voltage at which visible
temperature at which the vapor is ignited is the flash pas is generated is the visible gas generating voltage. It
point of that oil.
ts well known that as the voltage impressed on the
lire combustibility has been tested in the following oil-immersed sheet of paper is increased, visible gas is
manner. A clean glass sleeve obout 5 mm in diameter 15 generated immediately before breakdown occurs.
and about ?0 mm in length is dipped in the insulating 'Therefore the visible gas generating voltage can be
oil to be tested for one minute, after which it is taken taken as a measure of breakdown of the insulation of
out of the oil so as to be held horizontal for one minute. the oit-immersed paper.
TABLE 2
Characteristics
Viscosity (Cp)
(stwrc)
Specific gravity
<( is*c>
Flash point
rc>
Combustibility
Insulating all A volume ratio
txf
so 10 10 so
ss so
MO to 30 SO 40
45 SO
is
4) 41 SI 34
SO
1.09 1.07
1 04 1 02 1.00
0.99
163 Incombustible 155 ISI 146 144 Combustible
142 **
Characteristics
Dielectric constant (at S0*C|
Dielectric 1ms tangent
(*> (at I0*C)
Volume resistivity
(fl-em)
Visible pas generating
voltage (kV)mm)
Insulating oil
A volume ratio
TXF VO 0
TO *0
SS so
MO 10
SO SO 40
45 SO
3.07
4 15 4.SI 3.92 3 70 3 SO
0.21 020 0 15 0 12
0 to 0.01
1.0*10*' 1 SxiO" 39*10" .7.0XJ0" 9.0X10"
9.0X10"
57 0
37.0 36 3 562 35 1 SS.3
Then flame having a length of about 5 mm is applied
Characteristics `
Insulating oil A volumt ratio
TXF 90 so 70 <0
SS $0
AO 10 20
30 40
43 50
Characteristics
Insulating oil A volume tatio
TXF 90 10
70 60 93 90
AB 10 20 so 40 45 so
TABLE 3
Viscosity <cp|
(t30*C)
Specific itavily
(at 15*C)
Flash point
PC I
Combustibility
79 63 32 40 34 32
Dielectric constant (at IU*C)
t.09 07 1.04 1 02 too 0.94
Dielectric loss tangent
<*> (at *0*0
161 Incombustible 160 159 141
148 Combustible 145
Volume resistivity
(flcm)
Visible gas generating
voltage (kV/mm)
506 4 IS 4.31 5 47 3.70 9.50
021 020
0 16 0 19 0 10 (. 001
1,0x10"
1.3x(0" 4 0x10" 7 2x|0" I.SxlO" 9 5x10"
510 57 0
56 t
56 2 36 3 36.0
HONS 060422
Cheracteriitkct
Insulating oil
f volume ratio
TXf 90 0 70
00
AN 10 20
10 40
99 49 90 90
Charade ritlki
Insulating oil ft volume ratio
Txr 90
10 70 90
AN
10 20 10 40
95 4S 90 90
5
TABLR4
Viscosity (epl
(at J0*C)
Specific gravity
(at 15V)
Flash *v7
3,959,162
Combustibility
75 60 47 14 12 21
Dielectric constant (at I0*C)
III 1.09 1.07 1.05 104 I.OS
Dielectric lot* tangent
(*> (at 10V)
171 Incombuilible 16) ** ISI " 1)4 "
15) Combustible
151
Volume rciislivily
(flem)
Vitible gat generating
voltage (kV/mm>
9.25 5.05 4.51
4 19 1.90 110
0.20 0.20 0.17
0.1)
0.10 0 09
1.0x10'* 1tx|0" 4.0X10" 7.5X10"
l.lKtO'* 9.0X10"
51.0 51.5 59.5
61.0
61.5 62.0
TABLE 5
Characteristics
Vlacotlty
fep) (at 10V)
Specific gravity
(at I9*C)
Intulating oil
A volume ratio
Txr 90
90 70 60
DAA 10
20 10 40
59 45 90 SO
75 62 41 95
91 21
110
1.09 1.07 1.09 1.09 1.01
Characteristics
Dielectric constant (at 10*)
Dielectric lot* tangent
<%> (at 90V)
Imutatirtg oil ft volume ratio
TXP DAA 90 10
20 10 60 40
90 50
526 906 4.51 4.16
5.57
020
0.20 0.20 0.14 009 0.07
Flash point (V)
Combuttibilily
179 Incombuilible 164
160 192 150 Combuttlble
150
Volume retitlivlty
(ft-cm)
Visible pat generating
voltage (kV/mm)
1.0X10"
20X10" 4.0X10"
7.0X10" Ox 10"
9.5X10"
60.0 590 61.5 625
61.5
Charaderittict
Insulating oil ft volume ratio
0 70 00
SJ
Cbaradcritllei -
Intulating oil
6 volume ratio
txr
PO
90
70 90
TABLE 6
Viscosity
(cp) (at !0*C)
Specific gravity (at 15V)
70
04 47 19
12
SO
Dielectric constant
(I 90*0
| 04 1.04 1.09 100 0.91 0.97
Dielectric lots Kngent
(*) (at 10*)
9 11 496 4.50
0 20
0 20 0 14
Flub point (V)
Combuttibilily
|T0 Incombutlibk
100 " DO " 141 " 144 CombuttiWe
142 "
Volume resistivity (ft-cm)
Visible cat generating
voltage (kV/tnm)
1.0x10" 20X10" J.5XI0"
6
MCNS 060423
Characteristic*
55 45 SO 50
3,959,162 7
TABLE 6-continucd
Viicority
Upl (at JO'C)
Specific
Ftah
(tT
CftmbuMihility
4.04
5.42 Ml
0-12
0 10 0.0R
i.oxio" 4.0X10" 4.5*10"
ss.o 330
310
Chiiwitrlnici
Inuulating oil H lmt ratio
00 10 0 20 TO SO M 40 55 45 SO SO
Intulating oil A volume ratio
NO 10 10 SO TO SO 40 55 4S SO SO
TABLE 7
Vfccotily lepi
(at 30*C)
Specific gravity (at IS*C)
Plain point <*C>
iCombustibility
74 45 44 54 52 SO
Difl'etric constant (at 0*C)
110 1.01 103 1.0) 0 95 0 41
(Metectrk Iota tangent
<*> (at 10X)
172 145
Incombuttlble < .
tsa
141
144 Combustible
144
Volume
resistivity (0<m)
Vktible gat
ecncratint voltage
(kV/mmi
5 II 4.41 4.50 4.04
142 S.4I
0 20 0.20 0 15 12
0.10 0.04
1.0*10" 10*10" 1.5*10" 4.0*10" 4.0*10" 1.0*10"
STS S7.0 54.5 55 0
54 0
55.0
Cbaracterlatlca
Intulatlng oil
A volume ratio
txp 40 40
DME
10 20 SO 40
so 90
Intulatlng oil
A volume ratio
TXP DME 10
TO SO
40
SO SO
TABLE 8
Viscosity
(ep| (at )0*C
Specific
40 44.5 55 24
SO
24
Dielectric conetant (at S0*C)
1.10
1.04
I4ff
103 1.05 1.02
Dlclaetrlc lots tangent
<*>
(at 40*C>
5 45
520 SOS
4.40 4.SO 4.40
010
0.25 0.25
0.20 0.14 0.17
Flash point (Cl
<Combustibility
172 Incombuttlble
144 " ISS *
144 144 Combustible
142 "
Volume resistivity
((l*m)
Vieibte pai aencratme
voltage
(hV/mm)
2.0*10" 1.0*10" 7.5*10"
10*10" 5*10"
410 41.5 42 0
Cbaraetcrietici
Iniulallng ell A volume ratio Txr DPE *0 10 10 20
TO )0
*0 40
TABLE 9
Viseortty
<ep) (at J0*C1
Specific
,S`%
J 74
41 IN 4) 1.05
40 I 01 H 1.02
Flash point (*C>
Combuttibility
Incombuttlble Combustible
8 HONS 060424
Characteristics
CliifitItitlMci
Insulating oil A volume ratio
TXP 90 0 70 to 95 SO
DPE . 10
30 90
40 49 so
9
TABLE 9-continued
Viscosity (cpl
(at 90t')
Specific gravity
(at IS*C)
Flash point
ec
3,959,162
Combustibility
Dielectric constant
(at I0*C>
Die Icctric Ion tangent
(at 10*0
Volume resistivity
(fl-cm)
Visible gas generating
voltage
(IV/irnn)
S.7S $45
$-50
s.os 4 15
4 70
0.31 0.31 0.24
020 o.ta o.tt
1.0x10" 3 0X10"
J.$xl0"
7.0X10" 1.5x10" 7.0x10"
99.0 99.0 40 5
410 42 0 4)0
10
Cheiectcrlilici
Insulating oil A volume ratio TXP MO AN 0 5 5 10 10 10 70 10 30 40 30 30 55 90 35 SO 20 90
Charactcritllrs
Insulating oM A volume ratio TXP MO AN 90 9 9 0 10 10 70 10 30 40 30 30 59 90 25 50 30 90
TABLE 10
Viscosity
<P> (at 30*0
Specific gravity
(at 13*0
Flash point
1*0
Combustibility
77 42 44 97 33 31
Dielectric constant (at 0*C>
109
1.07 I.0S 1.03 t-02 1.01
Dielectric lost tangant
<*> (at 90*0
144 1Incombustible 142 " 154 " ISO "
11144 Combustible
149
Volume resistivity (fl-cis)
Visible gas
acnaralint voltage
(kV/mm)
9 13 4.91 4.47 4.07
995 9.45
0.20
0.30 0.15 0 12 0.10
o.ot
10X10" 1.5x10"
4.0X10" 7.OX IO"
9.0X10" 9.0X10"
57.5 51.0 390 59.0 57.3
310
Characteristics
Insulating oil A volume ratio
TXP 90 10 TO
S3 SO
AN
S 10
10 30 90 30
IME 5 10
30 30 2590
Insulating oil A volume tatio
DME 9
90 10 10 70 10 20
20 20
SO 20 90
TABLE 11
Viscosity
(cp) (at 90*0
Specific gravity (at 1ST)
Flash point CO
Combustibility
II 4S 54 4) 99 94
Dielectric constant (at 10*0
1.14 t.ll 1.07 1 04 1.02 1.00
Dielectric loss tangent
<> (at 10*0
146 Incombustible ISI 154 ** 149 " 147 Combustible 14$
Volume resistivity (O-cmi
Visible gas generating
voltage
(kV/mm)
5.44
5.23 4.91 4.54 4.34 4.42
0.29 025 0.24 0.20 0 t 0.15
1.5x10"
2.7X10" 92x|0"
7.9X10" 1jxto" 9.5x10"
5*0 57.5 59 5 41.5
62.5
MOWS 060425
\
4-
3,959,162 11
12
TABLE 12
Out aclefiuict
Vbcotily (cp)
(Bt MFC)
Specific gravity
(< I3*C|
Fla* point ro
Comhuitibilily
ImuUiIdi ell 4 volume ratio
TXP MO OMC 90 5 S 10 10 10 70 10 50 so HI 50 95 50 55 90 TO 30
17 SB 55 44
40 35
1.17 1.09 105 1.03
1 02 0.99
les Incombuttiblc I5S tS2 147
US Combuilible 142
Cbatarte rlttick
Dielectiic eonitani
<( *0*C)
Dielectric
loti tangent
() (at *0*0
Volume tekittiviijr
Viiiblc |ai generating
voltage (kV/mm)
lniitlln| oil
4 volume ratio
TXP MO DMF. 00 5 > 10 10 10
TO 10 50 SO 20 20 55 90 20 SO 50 90
3.32 903 4 12 4.92
4 05 4 21
0.21 025 025 0 20 0.17 o.ts
I.SxlO"
2.5x10"
3.0X10** ?.|x|0 M
1.5*10" S.7XI0"
S7.0 570
57.0 56.0 55.5 5S.0
From the above TABLFS it is apparent that the mix
tures prepared in accordance with the invention have electrical characteristics such dielectric constant, visi
higher dielectric constants than that of mineral oil ble gas generating voltage and have little or no toxicity,
which It 2.20 at 80*C Also the mixed oils of the inven so that the oil compositions of the invention are highly
tion have higher visible gas generating voltage than that valued in industrial use.
'
of mineral oil which is 47.0 kV/mm. This means that 30 What we ciaim is:
the mixed oils prepared in accordance with the inven
I. An insulating oil composition for use in electrical
tion are superior to the conventional insulating oil com devices, comprising trixylcnylphosphate and from 10%
prising mineral oil alone with respect to dielectric con to 40% by volume of insulating oil having a viscosity of
stant and visible gas generating voltage.
5 cp to 15 cp at 30`C
With respect to combustibility, mineral oil is combus IS 2. An insulating oil composition for use in electrical
tible and the mixtures which comprises TXP and 45% devices, comprising trixylenylphosphate and from 10%
and 50%, respectively, or the insulating oils are also to 40% by volume of a tingle kind of insulating oil
combustible. AH. AN, DAA and all the other insulating having a viscosity of 5 cp to 10 cp at 30*C.
oils to be mixed with TXP are individually combustible,
3. An insulating oil composition for use in electrical
so that if the amount of the oil mixed with TXP exceeds 40 devices, comprising trixylcnylphosphate and from 10%
50% by volume, the resultant mixture will apparently to 40% by volume of a mixture of a plurality of insulat
become combustible. Therefore, the maximum volmc ing oils having a viscosity of 5 cp lo 15 cp at 30*C.
of the insulating oil or oils to be mixed with TXP is
4. The composition of claim 2, wherein said insulat
determined to be 40% so as to prevent the resultant ing oil is a mineral oil.
mixture from becoming combustible.
45 5, The composition of claim 2, wherein Mid insulat
From the above TABLFS it can be seen that as the ing oil is an alkylbcnzene.
volume of the insulating oil or oils to be mixed with
6. The composition of claim 2, wherein said insulat
TXP it increased, the dielectric constant of the resul ing oil is an alkylnaphthalene.
tant mixture becomes lower. Therefore the volume to
7. The composition of claim 2, wherein said fnsuJat-
be mixed with TXP should not be very large.
30 ing oil is 2-diphcnylmcthylcthcr.
The experiments have disclosed that TXP alone is
8. The composition of claim 2, wherein said insulat
incombustible. However, the viscosity of the com ing oil is 2-diphcnylisopropylcthcr.
pound is as high as 76.0 cp, so that if it alone is used as
9. The composition of claim 2, wherein said insulat
1
Insulating oil in an electrical device, problems occur ing oil is a paraffin hydrocarbon oil. due to its poor cooling effect and low degree of immer 35 10. The composition of claim 2, wherein said insulat
sion.
ing oil is a naphthene hydrocarbon oil.
Unlike diphenyl chloride, the mixed insulating oils of
II. The composition of claim 3, wherein said plural
the invention have little toxicity, to that their use in ity of insulating oils are selected from the group con
electrical devices arc desirable from the viewpoint of sisting of mineral oils, alkylbcnzcnes, alkylnaphtha-
environmental pollution and sanitation.
60 lenes, 2-diphcnylmcthylcthcr, 2-diphenyliso-
As can be seen from the foregoing description, the propylcthcr, paraffin hydrocarbon oils and naphthene
Insulating oil compositions of this invention arc incom hydrocarbon oils.
bustible and superior to the conventional mineral oil in
6$
MtiNS 060426