U.S. patent application number 09/739343 was filed with the patent office on 2001-08-30 for lubricating oil for flon refrigerant.
This patent application is currently assigned to Idemitsu Kosan Co.. Invention is credited to Kaneko, Masato.
Application Number | 20010018406 09/739343 |
Document ID | / |
Family ID | 17527619 |
Filed Date | 2001-08-30 |
United States Patent
Application |
20010018406 |
Kind Code |
A1 |
Kaneko, Masato |
August 30, 2001 |
Lubricating oil for flon refrigerant
Abstract
A lubricating oil for a flon refrigerant, containing a
polyglycol compound having a kinematic viscosity at 40.degree. C.
of at least 30 cSt, a viscosity index of at least 150 and a water
content of not more than 200 ppm as a main component. The
lubricating oil of the present invention has good stability in the
presence of a flon refrigerant, does not cause the copper plating
phenomenon and has good compatibility with not only flon-11 and
flon-12 but also sparingly soluble refrigerants such as
hydrogen-containing flon compounds and perfluoroalkane.
Inventors: |
Kaneko, Masato; (Chiba-ken,
JP) |
Correspondence
Address: |
OBLON SPIVAK MCCLELLAND MAIER & NEUSTADT PC
FOURTH FLOOR
1755 JEFFERSON DAVIS HIGHWAY
ARLINGTON
VA
22202
US
|
Assignee: |
Idemitsu Kosan Co.
1-1 Marunouchi 3-chome, Chiyoda-ku
Tokyo
JP
|
Family ID: |
17527619 |
Appl. No.: |
09/739343 |
Filed: |
December 19, 2000 |
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Current U.S.
Class: |
508/579 ;
252/68 |
Current CPC
Class: |
C10N 2020/01 20200501;
C10M 2209/108 20130101; C10M 2209/105 20130101; C10M 2211/022
20130101; C10N 2040/00 20130101; C10N 2040/30 20130101; C10N
2040/44 20200501; C10N 2040/40 20200501; C10M 2209/109 20130101;
C10N 2040/34 20130101; C10M 2209/103 20130101; C10N 2040/38
20200501; C10N 2040/42 20200501; C09K 5/044 20130101; C10M 2209/107
20130101; C10N 2040/32 20130101; C10M 2211/06 20130101; C10M
171/008 20130101; C10M 2209/104 20130101; C10N 2040/36 20130101;
C09K 5/045 20130101; C10M 107/34 20130101; C10N 2040/50
20200501 |
Class at
Publication: |
508/579 ;
252/68 |
International
Class: |
C10M 17/34; C09K
005/00 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 30, 1987 |
JP |
273418/1987 |
Claims
What is claimed is:
1. A lubricating oil for a flon refrigerant, containing a
polyglycol compound having a kinematic viscosity at 40.degree. C.
of at least 30 cSt, a viscosity index of at least 150 and a water
content of not more than 200 ppm as a main component.
2. The lubricating oil as claimed in claim 1 wherein the polyglycol
compound is represented by the general formula:
R.sup.1O--R.sup.2.paren close-st..sub.nOR.sup.3 (wherein R.sup.1
and R.sup.3 are each hydrogen, an alkyl group having 1 to 20 carbon
atoms, or an acyl group, R.sup.2 is a straight or branched alkylene
group having 2 to 4 carbon atoms, and n is a number of at least
10).
3. The lubricating oil as claimed in claim 1 wherein water content
of the polyglycol compound is not more than 100 ppm.
4. The lubricating oil as claimed in claim 1 wherein a flon
refrigerant is fluorine-containing alkane selected from the group
consisting of trichloromonofluoromethane, dichlorodifluoromethane,
1,1-dichloro-2,2,2-trifluoroethane, 1,1,1,2-tetrafluoroethane,
1-chloro-1,1-difluoroethane, 1,1-difluoroethane, trifluoromethane,
monochlorodifluoromethane, 1,1,1,2,2,2-hexafluoroethane and
tetrafluoromethane.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a lubricating oil for flon
refrigerant and more particularly to a lubricating oil containing,
as a main component, polyglycol compound with high viscosity and
small water content, which is suitable for a lubricant in
refrigerators using a flon compound as a refrigerant and so
forth.
[0003] 2. Description of the Related Arts
[0004] Polyglycol compounds have heretofore been used as
lubricating oils for refrigerators and so forth. When they are used
in an open-type refrigerator and so forth, an evaporation loss is
large because their viscosities are relatively low. Particularly
when they are used in a high-speed and multi cylinder refrigerator,
the amount of oil consumed is considerably large, and thus they are
unsuitable for practical use. Moreover, when they are used in
closed type and half-closed type refrigerators and so forth, they
suffer from disadvantages in that the amount of oil recycled is
increased and cooling performance is decreased. Conventional
polyglycol compounds, when used as refrigerator oils and so forth,
produce the copper plating phenomenon on the iron surface in
refrigerators (this copper plating phenomenon means a phenomenon
that copper eluted from copper pipes covers the iron surface) and
thus have a danger of causing unsatisfactory working of vane,
bearings and so forth.
[0005] The present inventors have studied to overcome the above
defects of conventional polyglycol compounds and to develop a
polyglycol compound having suitable properties as refrigerator oils
and so forth. As a result, it has been found that water contained
in polyglycol compounds is responsible for the above copper plating
phenomenon. It has further been found that polyglycol compounds
having a small water content and a high viscosity do not have a
danger of causing the copper plating phenomenon and have good
compatibility with various flon compounds to be used as
refrigerants for refrigerators and so forth.
SUMMARY OF THE INVENTION
[0006] The present invention relates to a lubricating oil for a
flon refrigerator, containing a polyglycol compound having a
kinematic viscosity at 40.degree. C. of at least 30 cSt, a
viscosity index of at least 150 and a water content of not more
than 200 ppm as a main component.
DESCRIPTION OF PREFERRED EMBODIMENTS
[0007] The lubricating oil of the present invention contains a
polyglycol compound as a main component. The polyglycol compound
has a kinematic viscosity at 40.degree. C. of at least 30 cSt,
preferably 80 to 1,000 cSt and more preferably 120 to 800 cSt. If
the kinematic viscosity at 40.degree. C. is less than 30 cSt, the
amount of oil consumed or the amount of oil recycled is increased
by evaporation and, furthermore, sealing properties are poor. The
viscosity index of the polyglycol compound is at least 150 and
preferably at least 170. If the viscosity index is less than 150,
lubricating properties at high temperatures are reduced.
[0008] Among various polyglycol compounds satisfying the above
specified properties, polyglycol, polyglycolether or
polyglycolester represented by the general formula (I) is
preferable:
R.sup.1O--R.sup.2.paren close-st..sub.nOR.sup.3 (I)
[0009] In the general formula (I), R.sup.1 and R.sup.3 each are
hydrogen, an alkyl group having 1 to 20 carbon atoms, preferably 1
to 10 carbon atoms, or an acyl group, and R.sup.2 is a straight or
branched alkylene group having 2 to 4 carbon atoms. n is 10 or
more, preferably 20 to 150 and more preferably 30 to 120.
[0010] The water content of the polyglycol compound of the present
invention is not more than 200 ppm and preferably not more than 100
ppm. If the water content is more than 200 ppm, the copper plating
phenomenon may be caused. Such low water content polyglycol
compounds can be obtained by subjecting the polyglycol compound of
the general formula (I) to vacuum heating or by contacting the
polyglycol compound with silica gel, activated alumina, zeolite and
the like. It is particularly preferred that the polyglycol compound
be contacted with zeolite having a particle diameter of 0.1 to 10
mm, preferably 0.2 to 5 mm (natural zeolite or synthetic zeolite,
e.g., molecular sieves 3A, 4A, 5A, 13X). Contacting conditions are
not critical and can be determined appropriately depending on
circumstances. If necessary, supersonic waves of 10 to 50 KHz may
be applied at the contact treatment, and this application of
supersonic waves increases a dephydration efficiency. Since the
polyglycol compound having a small water content as obtained above
is hygroscopic, it is preferably stored under shielding conditions
of moisuture. Concretely, the polyglycol compound is stably stored
by placing it in a sealed container with a molding obtained by
solidifying zeolite by itself or using a binder, e.g., magnesium
oxide.
[0011] The lubricating oil of the present invention contains the
polyglycol compound having high viscosity, high viscosity index and
low water content as obtained above, as a main component. If
necessary, an anti-wear agent, a chlorine-capturing agent, an
antioxidant, a metal deactivator, a defoaming agent and so forth
can be added. Preferred examples of the chlorine-capturing agent
are phosphorous acid esters such as triphenyl phosphite and
tricresyl phosphite. The amount of the chlorine-capturing agent
added is 0.001 to 0.5% by weight.
[0012] The lubricating oil of the present invention is effective as
a lubricant for refrigerators, coolers, heat pumps and so forth
using a flon compound as a refrigerant. In the specification, flon
compound means fluorine-containing alkane. Typical examples of the
flon compound are trichloromonofluoromethane (flon-11) and
dichlorodifluoromethane (flon-12). The lubricating oil of the
present invention has good compatibility or solubility with, as
well as flon-11 and flon-12, hydrogen-containing flon and
perfluoroalkane which are said to be sparingly compatible with the
usual lubricating oil. Examples of such hydrogen-containing flons
are 1,1-dichloro-2,2,2-trifluoroethane (flon-123),
1,1,1,2-tetrafluoroethane (flon-134a), 1-chloro-1,1-difluoroethane
(flon-142b), 1,1-difluoroethane (flon-152a), trifluoromethane
(flon-23) and monochlorodifluoromethane (flon-22). Examples of
perfluoroalkane are 1,1,1,2,2,2-hexafluoroethane (flon-116) and
tetrafluoromethane (flon-14).
[0013] The lubricating oil of the present invention has good
stability in the presence of a flon refrigerant, does not cause the
copper plating phenomenon, and has a low two phase separation
temperature not only for flon-11 and flon-12 but also for sparingly
soluble refrigerants such as hydrogen-containing flon compounds and
perfluroalkane, i.e., has good compatibility therewith. Moreover
the lubricating oil of the present invention has advantages in that
anti-seizure properties are good, the amount of oil consumed by
evaporation is small, and the amount of oil recycled can be
decreased.
[0014] Accordingly the lubricating oil of the present invention is
effectively used as a lubricating oil for refrigerators, coolers
(particularly air conditioners for cars), heat pumps and so forth,
using various flon compounds as refrigerants.
[0015] The present invention is described in greater detail with
reference to the following examples.
EXAMPLES 1 to 3
Comparative Example 1 to 3, and Reference Examples 1 to 4
[0016] The mineral oil, alkylbenzene and polyglycol samples shown
in Table 1 were evaluated by the following methods. The results are
shown in Table 2.
[0017] Two Phase Separation Temperature of Flon-22
[0018] A sample and flon-22 were mixed in a ratio of 2 to 8 (by
weight) and a temperature at which the mixture was separated into
two phases was measured.
Two Phase Separation Temperature
[0019]
1 X More than 10.degree. C. .largecircle. 10 to 0.degree. C.
.circleincircle. Less than 0.degree. C.
[0020] Falex Seine Test
[0021] Measured according to ASTM D 3233 and indicated in terms of
seizure load (pounds).
[0022] Shield Tube Test
[0023] A 2:1 (by weight) mixture of a sample and flon-22 was placed
in a glass tube along with a catalyst of iron, copper and aluminum
and sealed. After heating at 175.degree. C. for 720 hours, the
appearance and the formation of precipitate were examined.
[0024] Evaporation Test
[0025] According to JIS C-2320, 20 g of a sample was placed in a
beaker and heated at 140.degree. C. for 24 hours, and thereafter
the amount lost by evaporation (wt %) was measured.
2TABLE 1 Kinematic Viscosity Average Water Sample at 40.degree. C.
Viscosity Molecular Content No. Type of Sample (cSt) Index Weight
(ppm) I Paraffinic 93 92 580 20 Mineral Oil II Naphthenic 97 43 585
32 Mineral Oil III Alkylbenzene 29 <0 340 25 IV Polyglycol
.sup.*1 20 171 500 250 V Polyglycol .sup.*2 227 213 1900 280 VI
Polyglycol .sup.*3 616 251 3000 320 VII Dehydrated 616 251 3000 50
Polyglycol .sup.*4 VIII Dehydrated 616 251 3000 100 Polyglycol
.sup.*5 IX Water-added 616 251 3000 2000 Polyglycol .sup.*6 X
Dehydrated 46 190 1000 100 Polyglycol .sup.*7 .sup.*1 Unilube
50MB-5 produced by Nippon Yushi Co., Ltd. .sup.*2 Unilube MB-38
produced by Nippon Yushi Co., Ltd. .sup.*3 Unilube MB-700 produced
by Nippon Yushi Co., Ltd. .sup.*4 Dehydrated Unilube MB-700 .sup.*5
Dehydrated Unilube MB-700 .sup.*6 Unilube MB-700 added with water
.sup.*7 Dehydrated Unilube MB-11 by Nippon Yushi Co., Ltd.
[0026]
3TABLE 2 Two- Phase Evap- Separation ora- Sam- Temp- Saizure Shield
Tube Test tion ple erature Test Appear- Precip- Test No. No.
(.degree. C.) (pounds) ance itate (wt %) Reference I X 400 Good
None 0.5> Example 1 Reference II X 450 Yellow- Precip- 0.5>
Example 2 brown itated Reference III .circleincircle. 250 Good None
20.3 Example 3 Comparative IV .circleincircle. 650 Little None 27.6
Example 1 copper plating Comparative V .circleincircle. 680 Little
None 15.8 Example 2 copper plating Comparative VI .circleincircle.
690 Little None 13.7 Example 3 copper plating Example 1 VII
.circleincircle. 700 Good None 12.4 Example 2 VIII .circleincircle.
690 Good None 12.6 Reference IX .circleincircle. 650 Consid- None
16.3 Example 4 erable copper plating Example 3 X .circleincircle.
670 Good None 17.5
* * * * *