Compositions – Vaporization – or expansion – refrigeration or heat or energy...
Reexamination Certificate
1998-06-09
2001-06-26
Ogden, Necholus (Department: 1751)
Compositions
Vaporization, or expansion, refrigeration or heat or energy...
C252S068000, C508S577000, C508S582000, C508S433000
Reexamination Certificate
active
06251300
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a refrigerator oil composition and a fluid composition for a refrigerator, and in particular to a refrigerator oil composition and a fluid composition containing said oil composition for use in a refrigerator, the refrigerator oil comprising a mixed base oil consisting essentially of an alkyl benzene oil having specific features and a synthetic oil and being suited for use in combination with an HFC refrigerant containing 1,1,1,2-tetrafluoroethane (HFC-134a) and/or pentafluoroethane (HFC-125).
2. Prior Art
Due to the recent problems as to the destruction of the ozone layer, the use of CFC (chlorofluorocarbon) and HCFC (hydrochlorofluorocarbon) which have been conventionally used as a refrigerant for a refrigerator is now restricted under a regulation. Therefore, as a replacement of these materials, HFC (hydrofluorocarbon) has been increasingly employed as a refrigerant.
Under the circumstances, PAG (polyalkylene glycol) and esters which are compatible with HFC have been studied or used as an oil for a refrigerator using an HFC refrigerant. For example, the use of PAG is proposed in U.S. Pat. No. 4,755.316; Japanese Patent Unexamined Publications Nos. Hei 1-198694, Hei 1-256594, Hei 1-259093, Hei 1-259094, Hei 1-259095, Hei 1-274191, Hei 2-43290, Hei 2-55791 and Hei 2-84491. The use of esters is proposed in PCT. Publication No. Hei 3-505602 as well as in Japanese Patent Unexamined Publications Nos. Hei 3-88892, Hei 2-128991, Hei 3-128992, Hei 3-200895, Hei 3-227397, Hei 4-20597, Hei 4-72390, Hei 4-218592 and Hei 4-249593.
However, PAG is rather high in hygroscopicity and poor in electric characteristics (volume resistivity). On the other hand, ester-based oils are readily hydrolyzed to generate an acid thus possibly giving rise to various problems. Moreover, these oils are accompanied with a serious problem that they are inferior in lubricity as compared with a mineral oil/CFC or a mineral oil/HCFC.
On the other hand, Japanese Patent Unexamined Publication No. Hei 5-157379 describes a refrigerating system for an HFC-134a refrigerant wherein there is used a refrigerator oil which is incompatible with a refrigerant; as an example of such an incompatible oil, an alkylbenzene oil is disclosed therein. Further, Japanese Patent Unexamined Publication No. Hei 5-59386 describes a mixed oil comprising a hydrocarbon compound and ester or ether, which is useful as a refrigerator oil for a refrigerator using tetrafluoroethane. However, it has been found that if an ordinary alkylbenzene oil is to be used as a refrigerator oil for HFC-134a and/or HFC-125, some specific means is required to be taken on the side of the system, and that if an ordinary alkylbenzene oil is used as a refrigerator oil for HFC-134a and/or HFC-125 without taking such specific means, the seizure of a refrigerating compressor used may possibly be caused after a long period of its operation.
The present inventors took notice of an alkylbenzene oil (alkylbenzenes) which is free from hydrolysis and hygroscopicity and made an extensive study to finally find out that if a mixture comprising an alkylbenzene oil having a specific property and a specific synthetic oil is used as a refrigerator oil for HFC-134a and/or HFC-125, the seizure of the refrigerating compressor can be avoided, thus indicating an excellent lubricity of the alkylbenzene oil, and that the alkylbenzene oil is capable of maintaining a high reliability for a long period of time. This invention has thus been accomplished in one aspect.
It has further been found out by the present inventors that when a phosphorus compound is added in a specific ratio to the above mixed base oil comprising an alkylbenzene oil having a specific property and a synthetic oil and the resulting mixture is used as a refrigerator oil composition in a refrigerator, the wear resistance and load resistance of the refrigerator can be improved. This invention has thus been accomplished in another aspect.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a refrigerator oil composition to be used with an HFC refrigerant containing HFC-134a and/or HFC-125, which enables a refrigerating compressor to be prevented from its seizure, is excellent in lubricity and retains high reliability for a long period of time.
Another object of the present invention is to provide a fluid composition for use in a refrigerator, which comprises the above refrigerator oil composition and an HFC refrigerant containing HFC-134a and/or HFC-125.
In a first aspect of this invention, there is provided a refrigerator oil composition for use with an HFC refrigerant containing HFC-134a, HFC-125 or a mixture thereof, which comprises component (A) and component (B), said component (A) being 70 to 99% by weight of an alkylbenzene oil containing at least 60% by weight, based on the total weight of component (A), of alkylbenzenes having a molecular weight of 200 to 350 and said component (B) being 30 to 1% by weight of at least one synthetic oil containing oxygen selected from the group consisting of an ester, a polyalkylene glycol, an alkyl ether of the polyalkylene glycol, a modified compound of polyglycol, a ketone, a polyphenyl ether, a silicone, a polysiloxane and a perfluoro ether.
In a second aspect of this invention, there is provided a refrigerator fluid composition which comprises:
(I) an HFC refrigerant containing HFC-134a, HFC-125 or a mixture thereof and
(II) a refrigerator oil comprising component (A) and component (B), said component (A) being 70 to 99% by weight of an alkylbenzene oil containing at least 60% by weight, based on the total weight of component (A), of alkylbenzenes having a molecular weight of 200 to 350 and said component (B) being 30 to 1% by weight of at least one synthetic oil containing oxygen selected from the group consisting of an ester, a polyalkylene glycol, an alkyl ether of the polyalkylene glycol, a modified compound of polyglycol, a ketone, a polyphenyl ether, a silicone, a polysiloxane and a perfluoro ether.
REFERENCES:
patent: 4046533 (1977-09-01), Olund
patent: 4199461 (1980-04-01), Olund
patent: 5154846 (1992-10-01), Thomas et al.
patent: 5262076 (1993-11-01), Ishida et al.
patent: 5391311 (1995-02-01), Ishida et al.
patent: 5431835 (1995-07-01), Katafuchi et al.
patent: 5445753 (1995-08-01), Fukuda et al.
patent: 5553465 (1996-09-01), Fukuda et al.
patent: 5554311 (1996-09-01), Katafuchi et al.
patent: 0496937 (1992-08-01), None
patent: 0557796 (1993-09-01), None
patent: 0693546 (1996-01-01), None
patent: 9005172 (1990-05-01), None
patent: 90/05172 (1990-05-01), None
Abstract of Japanese Pat. Appln. Laid-Open Gazette No. Hei 6-184576(A), Jul. 1994.
Sasaki Umekichi
Suda Satoshi
Takigawa Katsuya
Bucknam and Archer
Nippon Mitsubishi Oil Corporation
Ogden Necholus
LandOfFree
Refrigerator oil compositions and fluid compositions for... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Refrigerator oil compositions and fluid compositions for..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Refrigerator oil compositions and fluid compositions for... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2513112