DESCRIPTION
Title of Invention: REFRIGERATOR OIL COMPOSITION AND
REFRIGERATOR
Technical Field
5 [0001] The present invention relates to a refrigerating machine oil
composition, a working fluid composition for a rekigerating machine,
use of a composition comprising an ester-based base oil, an epoxy
compound, and a carbodiimide compound for a refrigerating machine
oil or a working fluid composition for a refiigerating machine, use of a
10 composition for manufacturing a refrigerating machine oil composition
or a working fluid composition for a refrigerating machine, and a
refiigerating machine.
Background Art
[0002] In a refiigerating machine such as cold storages and air
15 conditioners, a refrigerating machine oil is used with a refrigerant, in
order to prevent friction, wear, and seizure in a compression sliding
portion. Examples of the properties required for such refkigerating
machine oils include compatibility with a refrigerant and compatibility
with members inside the refrigerating machine.
20 [0003] That is, in addition to lubricity, thermal/chemical stability, and
refrigerant compatibility in the presence of a refi-igerant, the
refrigerating machine oil is required not to degrade the members when
coming in contact with the members of a refkigerating machine, and so
on. Thus, depending on the material of the members in the
25 refrigerating machine, it is suggested to use a refrigerating machine oil
which is compatible with them. For example, in the folloxving Patent
Literature 1, a refrigerating machine oil for suppressing degradation of
polyamide resin such as nylon is disclosed.
Citation List
Patent Literature
[0004] Patent Literature 1: Japanese Unexamined Patent Publication
NO. 2012-13 1994
Summary of Invention
Technical Problem
[0005] However, a refrigerating machine comprises members of various
types which differ in the physical or chemical characteristics, and it is
difficult to achieve compatibility with the members with one
refi-igerating machine oil.
[0006] In particular, it is extremely difficult to simultaneously achieve
compatibility with members containing polyethylene terephthalate and
compatibility with members containing hydrogenated acrylonitrile
butadiene rubber. In the case where a conventional refrigerating
machine oil is used, it is not possible to sufficiently suppress
degradation of both the members. Also, the degree of such
degsadation depends on types of refrigerants, and degradation of the
20 above described members tends to be significant under use of a
fluoropropene refi-igerant.
[0007] The present invention has been made in consideration of the
situation described above, and it is an object of the present invention to
provide a refjigerating machine oil composition and a working fluid
25 composition for a refrigerating machine which are compatible with any
of members containing polyethylene terephthalate and members
containing hydrogenated ac~ylonitrile butadiene rubber under use of a
fluoropropene refsigerant.
Solution to Problem
[0008] The present invention provides a refrigerating machine oil
composition comprising an ester-based base oil, an epoxy compound,
and a carbodiimide compound, wherein the refrigerating machine oil
composition is used with a refrigerant containing a fluoropropene in a
refrigerating machine comprising a member containing polyethylene
terephthalate and/or a member containing hydrogenated acsylonitrile
butadiene rubber.
[0009] It is preferred that the ester-based base oil comprise an ester of
pentaerythritol and a monocarboxylic fatty acid and/or an ester of
dipentaerythritol and a monocarboxylic fatty acid.
[0010] It is more preferred that the ester-based base oil comprise an
ester of pentaerythritol and a mixture of two or more monocarboxylic
fatty acids andor an ester of dipentaerythritol and a mixture of two or
more monocarboxylic fatty acids.
[0011] Also, the present invention provides a working fluid
composition for a refrigerating machine comprising the above described
20 refiigerating machine oil composition and a refrigerant containing a
fluoropropene, wherein the working fluid composition for a
reeigerating machine is used in a reftigerating machine comprising a
member containing polyethylene terephthalate andfor a member
containing hydrogenated ac~ylonitrileb utadiene rubber.
[0012] It may also be said that the present invention is use of a
composition for a refrigerating machine oil composition or a working
a~ ~,~ -,~ - ~ ~ -
A
i
fluid composition for a refrigerating machine, the composition
comprising an ester-based base oil, an epoxy compound, and a
carbodiimide compound, wherein the refiigerating machine oil
composition is used with a refrigerant containing a fluoropropene in a
refrigerating machine comprising a member containing polyethylene
terephthalate andlor a member containing hydrogenated aciylonitrile
butadiene rubber, and wherein the working fluid composition for a
refkigerating machine comprises a refrigerating machine oil composition
and a refrigerant containing a fluoropropene and is used in a
refi-igerating machine comprising a member containing polyethylene
terephthalate andfor a member containing hydrogenated aclylonitrile
butadiene rubber.
[0013] It may also be said that the present invention is application of a
composition for manufacturing a refrigerating machine oil composition
15 or a working fluid composition for a refrigerating machine, the
composition comprising an ester-based base oil, an epoxy compound,
and a carbodiiinide compound, wherein the refrigerating machine oil
composition is used with a refrigerant containing a fluoropropene in a
refkigerating machine comprising a member containing polyethylene
20 terephthalate andlor a member containing hydrogenated acrylonitrile
butadiene tubber, and wherein the working fluid composition for a
regigerating machine comprises a refiigerating machine oil composition
and a refrigerant containing a fluoropropene and is used in a
refrigerating machine comprising a member containing polyethylene
25 terephthalate and/or a member containing hydrogenated acrylonitrile
butadiene rubber.
[0014] Also, the present invention provides a refrigerating machine
comprising a refrigerant cisculation system containing a compressor, a
condenser, an expansion mechanism, and an evaporator, wherein the
refrigerant circulation system comprises a member containing
polyethylene terephthalate andor a member containing hydrogenated
acrylonitrile butadiene lubber, and wherein the refrigerant circulation
system is filled with a refrigerating machine oil composition comprising
an ester-based base oil, an epoxy compound, and a casbodiimide
compound and a refrigerant containing a fluoropropene.
Advantageous Effects of Invention
[0015] According to the present invention, it is possible to provide a
refrigerating machine oil composition and a working fluid composition -
for a refrigerating machine which are compatible with any of menibers
containing polyethylene terephthalate and members containing
hydrogenated ac~ylonitrile butadiene rubber under use of a
fluoropropene refrigerant.
Brief Description of Drawings
[0016] [Figure 11 Figure 1 is a schematic view showing an example of
the configuration of a refrigerating machine.
Description of Embodiments
[0017] Hereinafter, preferred embodiments of the present invention will
be described in detail.
[0018] A itfiigerating machine oil composition according to the present
embodiment comprises an ester-based base oil, an epoxy compound,
and a carbodiimide compound, and is used with a refrigerant containing
a fluoropropene in a refrigerating machine comprising a member
containing polyethylene terephthalate and/or a member containing
hydrogenated acrylonitrile butadiene rubber.
[0019] Also, a working fluid composition for a refiigerating machine
according to the present embodiment comprises a refrigerating machine
oil composition comprising an ester-based base oil, an epoxy
compound, and a carbodiimide compound, and a refrigerant containing
a fluoropropene, and is used in a refrigerating machine comprising a
member containing polyethylene terephthalate and/or a member
containing hydrogenated acrylonitrile butadiene lubber. It should be
noted that the working fluid composition for a refrigerating machine
according to the present embodiment includes an aspect comprising the
refiigerating machine oil composition according to the present
embodiment and a refrigerant containing a fluoropropene.
[0020] As the ester-based base oil contained in the reeigerating
machine oil according to the present embodiment, polyol esters obtained
by the esterification reaction of a polyhydric alcohol (polyol) and a
monocarboxylic acid (monocarboxylic fatty acid), complex esters of a
polyhydric alcohol, a monocarboxylic acid, and a polycarboxylic acid,
complex esters of a polyhydric alcohol, a monohydric alcohol, and a
polycarboxylic acid, or their mixtures are preferred.
[0021] As the above described polyhydric alcohol, neopentyl polyols,
such as neopentyl glycol, trimethylolpropane, pentae~ythritol, and
dipentaerythritol are preferred. As the above described
monocarboxylic acid, monocarboxylic acids in which the number of
carbon atoms is fiom 4 to 10 are preferred, and specific examples
include n-butanoic acid, n-pentatioic acid, 11-liexanoic acid, n-heptanoic
acid, n-octanoic acid, n-nonanic acid, n-decanoic acid, i-butanoic acid,
i-pentanoic acid, i-hexanoic acid, i-heptanoic acid, Zethylpentanoic
acid, 2-methylhexanoic acid, i-octanoic acid, 2-ethylhexanoic acid,
i-nonanic acid, 3,5,5-trimethylhexanoic acid, and i-decanoic acid. As
5 the above described polycarboxylic acid, dicasboxylic acids, such as
malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid,
suberic acid, and azelaic acid are preferred. As an alcohol and a
carboxylic acid constituting the above described ester, one alcohol and
one carboxylic acid may be used, and one or both of the alcohol and the
10 carboxylic acids may be used in combinations of two or more.
[0022] As the ester-based base oil, specifically, the following esters and
the following mixtures of esters are preferably used, for example:
esters of pentaerythritol and a mixed acid of 2-methylpropanoic
acid/3,5,5-trimethylhexanoic acid (at a molar ratio of 119 to 911);
15 esters of neopentyl glycol and a mixed acid of 2-ethylhexanoic
acid/3,5,5-trimethylhexanoic acid (at a molar ratio of 119 to 911);
esters of dipentaerythritol and a mixed acid of 2-ethylhexanoic
acid/3,5,5-trimethylhexanoic acid (at a molar ratio of 119 to 911);
esters obtained by allowing an ester intermediate fi-om reaction of
20 tsimethylolpropane with adipic acid to further react with 2-ethylhexanol
and distilling the remaining unreacted material off (at a molar ratio of 5
to 40 mol% of trimethylolpropane, 20 to 60 mol% of adipic acid, and 20
to 60 mol% of 2-ethylhexanol); and
esters of pentaerythritol and a mixed acid of n-pentanoic
25 acidln-heptanoic acid/3,5,5-trimethylhexanoic acid (at the molar ratio of
20 to 60 mol% of n-pentanoic acid, n-heptanoic acid and 5 to 40 mol%
of 3,5,5-trimethylhexanoic acid).
[0023] The refrigerating machine oil composition according to the
present embodiment may comprise a base oil other than ester-based
base oils. As the base oil, known mineral oils or synthetic oils may be
used, and it is preferred to use an ether-based base oil.
[0024] As the ether-based base oil, various types can be used, and
typical examples include polyether compounds represented by the
following formula (1):
[Chemical Formula I]
xf 0-( AO )"-R' ] m (1)
[In the formula (I), X represents a hydrocarbon group in the form of a
mono01 or polyol &om which a hydroxyl group is removed, A
represents an atkylene group in which the number of carbon atoms is
from 2 to 4, R' represents a hydrogen atom or an alkyl group in which
15 the number of carbon atoms is from 1 to 10, m represents the valence of
X, and n represents an integer of 2 or more].
In the fo~mula(I ), (AO),, represents one formed by connecting a total of
n groups selected from one or two or more of an oxyethylene group, an
oxypropylene group, and an oxybutylene group, and it is possible to
20 arrange each oxyalkylene group in (AO), in a desired order.
[0025] In the present embodiment, the content of the base oil is
preferably 20% by mass or more, and more preferably 40% by mass or
more, based on the total amount of the refrigerating machine oil
composition. The content of the ester-based base oil is preferably 20%
25 by mass or more, and preferably 40% by mass or more, based on the
total amount of the refrigerating machine oil composition.
[0026] The refsigerating machine oil composition according to the i
present embodiment comprises an epoxy compound and a carbodiimide I i
compound in addition to the above described base oil.
[0027] Examples of the epoxy compound include, but not palticularly
5 limited to, glycidyl ether-type epoxy compounds, glycidyl ester-type
epoxy compounds, oxirane compounds, alkyl oxirane compounds,
!
alicyclic epoxy compounds, epoxidized fatty acid monoesters, and
I
epoxidized vegetable oils.
[0028] As the glycidyl ether-type epoxy compound, it is possible to use,
10 for example, an aryl glycidyl ether-type epoxy compound or alkyl
glycidyl ether-type epoxy compound represented by the following
formula (2).
;
[0029]
[Chemical Fosmula 21
[In the formula (2), R~ represents an aryl group or an alkyl group in
which the number of carbon atoms is fsom 5 to 181.
[0030] As the glycidyl ether-type epoxy compound represented by the
formula (2), n-butylphenyl glycidyl ether, i-butylphenyl glycidyl ether,
20 sec-butylphenyl glycidyl ether, tert-butylphenyl glycidyl ether,
pentylphenyl glycidyl ether, hexylphenyl glycidyl ether, heptylphenyl
glycidyl ether, octylphenyl glycidyl ether, nonylphenyl glycidyl ether,
decylphenyl glycidyl ether, decylglycidyl ether, undecylglycidyl ether,
dodecyl glycidyl ether, tridecyl glycidyl ether, tetradecyl glycidyl ether,
25 and 2-ethylhexyl glycidyl ether are prefesred.
[003 11 If the number of carbon atoms of the alkyl group represented by
R' is 5 or more, the stability of the epoxy compound is ensured, and it is
possible to suppress decomposition before reaction with moisture, fatty
acid, and oxidization deteriorated material or self-polymerization
5 between epoxy compounds, and the intended fi~nctionb ecomes easy to
achieve, Meanwhile, if the number of carbon atoms of the alkyl group
represented by R' is 18 or less, the solubility in a refrigerant, in
particular, a hydrofluorocarbon refiigerant is well maintained, and it is
possible to make malfunctions such as cooling defects due to deposition
10 in refrigerating apparatuses less likely to occw
LO0321 Also, as the glycidyl ether-type epoxy compound, other than
epoxy compounds represented by the formula (2), it is possible to use
neopentyl glycol diglycidyl ether, trimethylolpropane triglycidyl ether,
pentaerythritol tetraglycidyl ether, 1,6-hexanediol diglycidyl ether,
15 sorbitol polyglycidyl ether, polyalkylene glycol monoglycidyl ethers,
polyalkylene glycol diglycidyl ethers and the like.
[0033] As the glycidyl ester-type epoxy compound, it is possible to use,
for example, those represented by the following formula (3).
[0034]
20 [Chemical Formula 31
[In the formula (3), R~ represents an aryl group, an alkyl group in which
the number of carbon atoms is from 5 to 18, or an alkenyl group].
(00351 As the glycidyl ester-type epoxy compound represented by the
25 fo~mula (3), glycidyl benzoate, glycidyl neodecanoate, glycidyl
-2,2-dimnethyloctanoate,g lycidyl acrylate, and glycidyl methacrylate are
preferred.
[0036] If the number of carbon atoms of the alky1 group represented by
R~ is 5 or more, the stability of the epoxy compound is ensured, and it is
5 possible to suppress decomposition before reaction with moisture, fatty
acid, and oxidization deteriorated material or ~el~polymerization
between epoxy compounds, and the intended hction becomes easy to
achieve. Meanwhile, if the number of carbon atoms of the allcyl group
or alkenyl group represented by R~ is 18 or less, the solubility in a
10 refkigerant, in particular, a hydrofluorocarbon rekigermt is well
maintained, and it is possible to make malfunctions such as cooling
defects due to deposition in rekigerating apparatuses less likely - to
occur.
LO0371 An alicyclic epoxy conlpound is a compound having a partial
15 structure represented by the following formula (4) in which carbon
atoms constitutingthe epoxy group directly constitute the alicyclic ring.
[003 81
[Chemical Formula 41
20 [0039] As the alicyclic epoxy compound, 1,2-epoxycyclohexane,
1,2-epoxycyclopentane,
3',4'-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate,
bis(3,4-epoxy~yclohexylmethyl)adipate, exo-2,3-cpoxynorbomane,
bis(3,4-epoxy-6-methylcyclohexylmethyl)adipate,
2-(7-oxabicyclo[4.1.0]hept-3-yl)-spko(1,3-dioxane-5,3'-[7]oxabicyclo[4
.l.O]heptane, 4-(l'-methylepoxyethyl)-1,2-epoxy-2-methylcyclohexane,
and 4-epoxyethyl-1,2-epoxycyclohexanea re preferred.
[0040]Examples of the allyloxirane compound include
5 1,Zepoxystyrene and alkyl-1,2-epoxystyrenes.
[0041] Examples of the alkyl oxirane compound include
1,2-epoxybutane, l,2-epoxypentane, 1 ,2-epoxyhexane,
1,2-epoxyheptane, 1,2-epoxyoctane, 1,2-epoxynonane,
1,2-epoxydecane, 1,2-epoxyundecane, 1,2-epoxydodecane,
10 1,2-epoxytridecane, 1,2-epoxytetradecane, 1,2-epoxypentadecane,
l,Zepoxyhexadecane, 1,2-epoxyheptadecane, 1,2-epoxyoctadecane,
1,2-epoxynonadecane, and 1,2-epoxyicosane.
[0042] Examples of the epoxidized fatty acid monoester include esters
of an epoxidized fatty acid in which the number of carbon atoms is &om
15 12 to 20 and an alcohol in which the number of carbon atoms is f?om 1
to 8 or a phenol or alkyl phenol. As the epoxidized fatty acid
monoester, butyl, hexyl, benzyl, cyclohexyl, methoxyethyl, octyl,
phenyl, and butylphenyl esters of epoxystearic acids are preferably
used.
20 [0043] Examples of the epoxidized vegetable oil include epoxy
compounds of vegetable oils, such as soy oil, linseed oil, and cottonseed
oil.
[0044] The content of the epoxy compound is preferably 0.1% by mass
or more and 4.5% by mass or less, more preferably 0.5% by mass or
25 more and 3.5% by mass or less, hrther preferably 1.0% by mass or
more and 2.5% by mass or less, based on the total amount of the
refiigerating machine oil composition. If the content is the above
described lower limit or more, it is possible to suppress an increase in
the acid value of the refsigerating machine oil composition. If the
content is the above described upper limit or less, even in the case
5 where the refrigerating machine oil composition is used with a
fluoropropene refi-igerant, it is possible to suppress a deterioration in a.
member containing polyethylene terephthalate and a member containing
hydrogenated acrylonitrile butadiene rubber.
[0045] As the carbodiimide compound, which is not particularly
10 limited, for example, it is possible to use dialkylcarbodiimide,
diphenylcarbodiimide, and bis(alkylpheny1)carbodiimide.
[0046] Example of the dialkylcarbodiimide include
diisopropylcarbodiimide and dicyclohexylcarbodiimide.
[0047] Examples of the bis(alkylpheny1)carbodiimide include
15 ditolylcarbodiimide, bis(isopropylphenyl)casbodiimide,
bis(diisopropylphenyl)carbodiimide,
bis(triisopropylphenyl)casbodiimide, bis(butylphenyl)carbod'imide,
bis(dibutylphenyl)carbodiimide, and bis(nonylpheny1)casbodiimide.
[0048] The content of the carbodiimide compound is preferably 0.01%
20 by mass or more and 1% by mass or less, more preferably 0.05% by
mass or more and 0.5% by mass or less, based on the total amount of
the refiigerating machine oil composition. If the content is the above
described lower limit or more, the stability of the refrigerating machine
oil composition is more increased. If the content is the above
25 described upper limit or less, it is possible to suppress occurrence of
sludge derived fiom additives during a long time of use.
[0049] The kinematic viscosity of the refsigerating machine oil
composition at 40°C can be preferably from 3 to 1000 rnm2/s, more
p~tferablyf rom 4 to 500 m d s , and further preferably from 5 to 400
mm2/s. The kinematic viscosity of the refrigerating machine oil
5 composition at 100°C can be preferably from 1 to 100 mm2/s and more
preferably from 2 to 50 mn2/s. The kinematic viscosity in the present
invention means the kinematic viscosity measused in compliance with
JIS K2283:2000.
[0050] The pour point of the refrigerating machine oil composition can
10 be preferably -10°C or less and more preferably -20°C or less. The
pour point in the present invention means the pour point measured in
compliance with JIS K2269-1987.
[0051] The volume resistivity of the refrigerating machine oil
composition can be preferably 1 .O x lo9 Q+m or more, more preferably
15 1.0 x lot0 C2.m or more, and fkrther preferably 1.0 x 10" Om or more.
In particular, in the case of being used for a hesmetic-type refrigerating
machine, it is preferred that the composition be highly insulating. The
volume resistivity in the present invention means the volume resistivity
at 25°C measured in compliance with JIS C2101: 1999.
20 [0052] The moisture content of the refrigerating machine oil
composition can be preferably 200 ppm or less, more preferably 100
ppm or less, and fit~therp referably 50 ppm or less, based on the total
amount of the refrigerating machine oil composition. Particularly, in
the case of being used for a hermetic-type refrigerating machine, it is
25 preferred that the moisture content be low, from the viewpoint of the
influence on the thermal/che~nicasl tability and the electrical insulation
property of the refi-igerating machine oil composition.
[0053] The acid value of the refrigerating machine oil composition can
be preferably 10.0 mgKOWg or less, more preferably 1.0 mgKOWg or
less, and fitsther preferably 0.1 mgKOWg or less. The hydroxy value
5 of refrigerating machine oil composition can be preferably 50.0
mgKOWg or less, more preferably 30.0 mgKOWg or less, and further
preferably 10.0 mgKOWg or less. It is preferred that the acid value
and the hydroxy value of the refrigerating machine oil be in the above
described range, from the viewpoints of prevention of conosion of the
10 metal used in a refrigerating machine or piping and of prevention of
degradation of the ester contained in the refrigerating machine oil
composition. The acid value in the present invention means the acid
value measured in compliance with JIS K2501:2003. The hydroxy
value in the present invention means the hydroxy value measured in
15 compliance with JIS K0070-1992.
[0054] The ash content of the refrigerating machine oil composition can
be preferably 100 ppm or less and more preferably 50 ppm or less, from
the viewpoint of increasing the thermaVchemica1 stability of the
refrigerating machine oil composition and suppressing the occurrence of
20 sludge and the like. The ash content in the present invention means the
ash content measured in compliance with JIS K2272: 1998.
[0055] In the present embodiment, in order to impart total performance,
it is possibIe to add the following additives or other known additives to
the ref7igerating machine oil composition as appropriate, within the
25 extent that the properties of the refrigerating machine oil composition
are not impaired.
Antiwear agent: sulfkr-based, phosphorous-based, zinc
thiophosphate-based, and the like;
Antioxidant: phenol-based, amine-based, phosphorous-based, and the
like;
5 Metal deactivator: benzotriazole (derivatives), thiadiazoles,
dithiocarbamates, and the like;
Oiliness agent: higher fatty acids, alcohols, amines, and the like; and
Antifoaming agent: silicone oils and the like.
[0056] The refrigerating machine oil composition according to the
10 present embodiment is used with a refrigerant containing a
fluoropropene, and also, the working fluid composition for a
refrigerating machine according to the present embodiment comprises a
refrigerant containing a fluoropropene.
[0057] As the fluoropropene refiigerant, fluoropropenes of which the
15 number of fluorine atoms is 3 to 5 are preferred, and it is preferred that
the fluoropropene refrigerant be any one of
1,2,3,3,3-pentafluoropropene (HFO-1225ye), 1,3,3,3-tetrafluoropropene
(HFO-1234ze), 2,3,3,3-tetrafl uoropropene (HFO-1234~9, 1,2,3,3-
tetrafluoropropene (HFO-1234ye), and 3,3,3-trifluoropropene
20 @O-1243zf) or a mixture of two or more of these. From the
viewpoint of refrigerant physical properties, it is preferred that the
refitgerant be one or two or more selected fsom HFO-1225ye,
HFO- 1234ze, and HFO-1234yf.
[0058] The refrigerant used with the refrigerating machine oil
25 composition according to the present embodiment may include
refkigerants other than fluoropropene. Examples of the refiigerant
other than fluoropropene include saturated hydrofluorocarbon
refrigerant, fluorine-containing ether-based refrigerants such as
perfluoroether, bis(trifluoro~nethyl)sulfide refrigerants,
trifluoroiodomethane refrigerants, and natural refrigerant, such as
5 dimethyl ether, carbon dioxide, ammonia, and hydrocarbons.
[0059] The refrigerating machine 02 composition and the working fluid
composition for a refrigerating machine according to the present
embodiment are preferably used for a refrigerating machine comprising
a member containing polyethylene terephthalate andlor a member
10 containing hydrogenated acrylonitrile butadiene rubber. Specific
examples of the refi~gerating machine include a refrigerating machine,
such as automobile - air conditioners comprising a reciprocating or rotary
compressor, air conditioners, dehumidifiers, cold storages, freezers,
freezing cold storages, vending machines, showcases, and cooling
15 apparatus for chemical plants.
[0060] Hereinafter, the aforementioned refi-igerating machine will be
described in more detail. Figure 1 is a schematic view showing an
example of the configuration of a refkigerating machine. As shown in
Figure 1, a refrigerating machine 10 comprises a refrigerant circulation
20 system in which at least a compressor 1, a condenser 2, an expansion
mechanism 4, and an evaporator 5 are successively connected by a
passage 6. The refrigerant circulation system may hrther comprise a
desiccator 3. Also, the rekigerant circulation system a member
containing polyethylene terephthalate andlor a member containing
25 hydrogenated acrylonitrile butadiene rubber.
[0061] In the compressor 1, a small amount of the refrigerant and a
large amount of the refrigerating machine oil composition coexist under
a high temperature (usually 70 to 120°C) condition. The reeigerant
released from the ref+igerant compressor 1 to the passage 6 is gaseous
and contains a small amount of (usually 1 to 10% of) the refrigerating
5 machine oil composition as mist, and in this mist refkigerating machine
oil composition, a small amount of the refsigerant is dissolved (point a
in Figure 1). Next, in the condenser 2, the gaseous re&igerant is
compressed to be high-density fluid, and under a relatively high
temperature (usually 50 to around 70°C) condition, a large amount of
10 the refrigerant and a small amount of the refrigerating machine oil
coexist (point b in Figure 1). Furthemore, the mixture of a large
amount of the refrigerant and a small amount of the refrigerating
machine oil is successively supplied to the desiccator 3, the expansion
mechanism 4, and the evaporator 5 to rapidly have a lower temperature
15 (usually -40 to O°C) (points c and d in Figure 1) and be retuned back to
the refrigerant compressor 1.
[0062] As the compressor 1, it is possible to use both open type
compressors, which have a prime mover externally, and hermetic type
compressors, which incorporate a motor internally.
20 [0063] Examples of the open type compressor include reciprocating
types such as pistonfcrank types and pistonfswash plate types, and
rotating types such as rotating piston types, rotary vane types, scroll
types, and screw types. Examples of the external prime movers
include engines and motors, but particularly in the case of automobile
25 air conditioners, it is common to use driving engines as extelnal prime
movers.
[0064] Examples of the hemetic type compressor include high-pressure
container-type compressors housing a motor comprising a rotor and a
stator in a sealed container storing a refrigerating machiie oil
composition, a rotation axis fitted in the rotor, and a compressor linked
5 to the motor via the rotation axis, wherein high-pressuse refrigerant gas
released fkom the compressor is retained in the sealed container, and
low-pressure container-type compressors housing a motor comprising a
rotor and a stator in a sealed container storing a refiigerating machine
oil composition, a rotation axis fitted in the rotor, and a compressor
10 linked to the motor via the rotation axis, wherein high-pressure
re~igerantg as released f?om the compressor is directly discharged out
of - the sealed container.
[0065] The desiccator 3 is packed with a desiccant such as synthetic
zeolites comprising, for example, silicic acid and alkali aluminate metal
15 complex salts.
[0066] In the refrigerant circulation system of the reeigerating machine
10, a member containing polyethylene terephthalate andlor a member
containing hydrogenated acrylonitrile butadiene subber are used in, for
example, insulating portions inside the compressor 1 and sealing
20 materials for preventing leakage of the refrigerant and the refrigerating
machiie oil composition in the compressor 1.
Examples
[0067] Hereinafter, the present invention will be described based on
Examples and Comparative examples, but the present invention is not
25 limited to the Examples.
[0068] In Examples 1 to 16, Comparative Examples 1 to 10, and
Reference Examples 1 to 2, the following base oils and additives were
used to prepare refrigerating machine oil compositions of which
compositions are shown in Tables 1 to 5, and the following material
cotnpatibility test was conducted on each refrigerating machine oil
5 composition obtained. The results are shown in Tables 1 to 5.
[0069] (Base oil)
Base oil 1: an ester base oil in which (al) an ester of pentaesythritol and
a mixed acid of 2-methylpropanic acid/3,5,5-tsimethylhexanoic acid (at
a molar ratio of 1/1) and (bl) an ester of neopentyl glycol and a mixed
10 acid of 2-ethylhexanoic acid/3,5,5-trimethylhexanoic acid (at a molar
ratio of 1/1) are mixed at a ratio of (al) 50% by mass:(bl) 50% by mass.
Base oil 2: an ester base oil in which (a2) an ester of pentaerythritol and
a mixed acid of 2-ethylhexanoic acidl3,5,5-trimethylhexanoic acid (at a
molar ratio of 1/1) and @2) an ester of dipentaesythsitol and a mixed
15 acid of Zethyhexanoic acid/3,5,5-trimethylhexanoic acid (at a molar
ratio of 111) are mixed at a ratio of (a2) 75% by mass:(b2) 25% by mass.
Base oil 3: an ester base oil obtained by reacting 2-ethylhexan01 (2.0
mol) with an ester intermediate of trimethylolpropane (1 mol) and
adipic acid (2.4 mol) and distilling the remaining unreacted material off.
20 Base oil 4: an ester base oil of pentae~ythritol and a mixed acid of
n-pentanoic acid/n-heptanoic acid/3,5,5-trimethylhexanoic acid (at a
molar ratio of 40/40/20).
[0070] (Additives)
(A) Epoxy co~npounds
25 Al: glycidyl neodecanoate
A2: 2-ethylhexyl glycidyl ether
A3 : 1,2-epoxytetradecane
A4: 3',4'-epoxycyclohexyItnethyl-3,4-epoxycyclohexanec asboxylate
(CELLOXIDE 2021P) I
I
(B) Ca~bodiimidec ompounds ii
5 B 1 : bis(diisopropy1phenyl)carbodiimide 1
B2: diisopropylcarbodiimide i I i
[0071] (Material compatibility test)
A sample of a strip made of hydrogenated acrylonitrile
butadiene rubber (H-NBR)o r polyethylene terephthalate (PET) placed
10 in a mixture of 80 g of a refrigerating machime oil composition and 20 g !
of 2,3,3,3-tetrafluoropropene refi-igerant (HFO-1234yf) of which
i
moisture content was adjusted to 500 ppm was heated in a 200 ml
autoclave at 150°C for 200 hours. After heating was hished, the acid
I I !
value of the refrigerating machine oil composition was measured, the
15 tensile strength of the strips made of H-NBR or PET was measured, and
the tensile strength change ratio (%) defined by the following formula
was calculated.
Tensile strength change ratio [%I = (Tensile strength of the strip
after the tesmensile strength of the strip before the test) x 100
20 [0072] The strips made of H-NBR and PET used in the test were each
shaped into the following form.
H-NBR: length x width x thickness = 5 cm x 2 cm x 0.2 cm
PET: length x width x thickness = 5 cm x 2 cm x 300 pm j I
The acid value was measured in compliance with JIS K2501 "Petroleun~ i
!
25 I products and lubricants - Determination of neutralization number", and
the tensile strength was measured in compliance with JIS K625 1.
[0073]
[Table 11

[Table 31
Balance

[0077]
[Table 51
[0078] 1 ... compressor, 2.. .condenser, 3 ... desiccator, 4. ..expansion
5 mechanism, S...evaporator, 6...passage, 10 ... refrigerating machine.

CLAIMS
1. A refrigerating machine oil composition comprising:
an ester-based base oil;
an epoxy compound; and
a carbodiimide compound,
the refrigerating machine oil composition being used with a
refrigerant containing a fluoropropene in a refrigerating machine
comprising a member containing polyethylene terephthalate and/or a
member containing hydrogenated acrylonitrile butadiene rubber.
10 2. The refrigerating machine oil composition according to claim 1,
wherein the ester-based base oil comprises an ester of pentaerythritol
and a monocarboxylic fatty acid andlor an ester of dipentaeqtlmtol and
a monocarboxylic fatty acid.
3. The refrigerating machine oil composition according to claim 1
15 or 2, wherein the ester-based base oil comprises an ester of
pentaerythritol and a mixture of two or more monocarboxylic fatty acids
and/or an ester of dipentae~ythritol and a mixture of two or more
monocarboxylic fatty acids.
4. Use of a composition for a refiigerating machine oil
20 composition, the composition comprising an ester-based base oil, an
epoxy compound, and a carbodiimide compound,
the refiigerating machine oil composition being used with a
refrigerant containing a fluoropropene in a reeigerating machine
comprising a member containing polyethylene terephthalate andor a
25 member containing hydrogenated acsylonitrile butadiene rubber,
5. Use of a composition for manufacturing a refiigerating machine
oil composition, the composition comprising an ester-based base oil, an
epoxy compound, and a carbodiimide compound, >
the reftigerating machine oil composition being used with a
reftigerant containing a fluoropropene in a rekigerating machine
5 comprising a member containing polyethylene terephthalate andlor a
member containing hydrogenated aclylonitxile butadiene lubber.
6. A re£rigerating machine comprising a refrigerant circulation
system containing a compressor, a condenser, an expansion mechanism,
and an evaporator,
10 the refrigerant circulation system comprising a member
containing polyethylene tesephthalate and/or a member containing
hydrogenated acrylonitrile butadiene lubber, and
the rekigerant circulation system being filled witfl a
refrigerating machine oil composition comprising an ester-based base
15 oil, an epoxy compound, and a carbodiimide compound and a
rekigerant containing a fluoropropene.