Solid anti-friction devices – materials therefor – lubricant or se – Lubricants or separants for moving solid surfaces and... – Heterocyclic ring compound; a heterocyclic ring is one...
Patent
1997-02-13
2000-08-01
Howard, Jacqueline V.
Solid anti-friction devices, materials therefor, lubricant or se
Lubricants or separants for moving solid surfaces and...
Heterocyclic ring compound; a heterocyclic ring is one...
549372, 252 68, C10M10518, C07D31718
Patent
active
060966920
DESCRIPTION:
BRIEF SUMMARY
TECHNICAL FIELD
The present invention relates to a synthetic lubricating oil using, as a base oil, cyclic ketals or cyclic acetals having a particular structure, and also to a working fluid composition for a refrigerating machine which uses the synthetic lubricating oil.
The present invention further relates to cyclic acetals which are useful as polar oils, organic solvents, lubricants, synthetic lubricating oils, or refrigeration oils, or as intermediates in the production of surfactants, organic solvents, polar oils, synthetic lubricating oils, refrigeration oils, etc., and to a method for producing the cyclic acetals.
BACKGROUND ART
With lengthened intervals of oil changes, need of energy-saving, use of high performance machines, and down-sizing of machines, demand for the performance of lubricating oils has become severe. In particular, lubricating oils with a high thermal stability and a high oxidation resistivity have been strongly sought. In the situation where there has been increasing public concern about global environmental pollution, such as depletion of ozone layer caused by freon, the earth warming due to excess carbon dioxide and methane, destruction of forests by sulfur dioxide and NO.sub.x in exhaust fumes, and pollution of soil and lakes due to chemical leakage, environmental protective measures have been strongly sought also in the field of lubricating oils.
In order to meet the requirements for high thermal stability and oxidation resistivity, ethers, such as polyalkylene glycols, and esters, such as aliphatic diesters and hindered esters, have been developed and used for engine oils, hydraulic oils, grease base oils, gear oils, rolling oils, precision instrument oils, etc.
However, ethers, such as polyalkylene glycols, have a higher polarity than conventionally used mineral oils to cause the following drawbacks: (1) high hygroscopicity, and (2) insolubility of additives which are conventionally used for lubricating oils. An ether synthesized from an alkyl halide and a polyol, which has a lower polarity than polyalkylene glycols, is described in Japanese Patent Examined Publication No. 1-29240. This ether also has a problem that a trace of residual halogen in the ether product may impair thermal stability and oxidation resistivity.
Esters also are not free from drawbacks. That is, carboxylic acid formed by hydrolysis of esters erodes metals, and esters tend to impair the effects of oiliness improvers and extreme pressure additives, though esters have a merit to reduce friction because they are well adsorbed onto metals.
Thus, synthetic lubricating oils with adequately low polarity, high thermal stability, high oxidation resistivity, no formation of carboxylic acids due to hydrolysis and low hygroscopicity are in high demand.
Recently, the use of dichlorodifluoromethane (CFC12) for refrigerators and car air conditioners is restricted, and will be legally banned at the end of 1995 in order to protect the ozone layer from the viewpoint of the environment of the earth, and also the use of chlorodifluoromethane (HCFC22) for room air conditioners is about to be legally regulated. Thus, hydrofluorocarbons which do not destroy the ozone layer, such as 1,1,1,2-tetrafluoroethane (HFC 134a), difluoromethane (HFC32), and pentafluoroethane (HFC125), have been developed as substitutes for CFC12 or HCFC22.
However, since the polarity of hydrofluorocarbons is higher than that of CFC12 or HCFC22, the use of conventional lubricating oils, such as naphthene mineral oils, poly-.alpha.-olefins and alkylbenzenes, causes two-phase separation of the working fluid at low temperatures. This is due to poor compatibility between the conventional lubricating oils and the hydrofluorocarbons. Two-phase separation hampers oil return, which in turn interferes with heat transfer due to deposition of a thick oil film around the condenser and evaporator used as heat exchangers. It can also cause significant failures, such as poor lubrication and foaming upon starting operation. Therefore, the conventional refrigeratio
REFERENCES:
patent: 1934309 (1933-11-01), Hoover
patent: 3714202 (1973-01-01), Nakaguchi et al.
patent: 3725438 (1973-04-01), Barone et al.
patent: 3741986 (1973-06-01), Hartmann
patent: 3900411 (1975-08-01), Andress, Jr.
patent: 3910845 (1975-10-01), Coon
patent: 4076727 (1978-02-01), Zey et al.
patent: 4659809 (1987-04-01), Matsumura
patent: 4755316 (1988-07-01), Magid et al.
patent: 4851144 (1989-07-01), McGraw et al.
patent: 5395544 (1995-03-01), Hagihara et al.
patent: 5523010 (1996-06-01), Sorensen et al.
patent: 5575944 (1996-11-01), Sawada et al.
patent: 5720895 (1998-02-01), Nakagawa et al.
Chemical Abstracts, vol. 77, No. 9, Abstract No. 61237u (XP-002097541), Jun. 29, 1990.
Hagihara Toshiya
Kobayashi Yuichiro
Nakagawa Shoji
Sakai Akimitsu
Taira Koji
Howard Jacqueline V.
Kao Corporation
LandOfFree
Synthetic lubricating oil does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Synthetic lubricating oil, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Synthetic lubricating oil will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-663793