Abstract:
A refrigerator oil, particularly a refrigerator oil for a hydrofluorocarbon refrigerant, comprising a base oil composed of an oxygen-containing organic compound, such as a polyalkylene glycol and polyester, and a fluorinated silicone oil having a kinematic viscosity of 500 mm.sup.2 /sec or more at 25.degree. C. is disclosed. A process for lubrication of a refigeration system comprising lubricating a compression-type refrigeration system by using the refrigerator oil is also disclosed.By using the refrigerator oil, the foaming phenomenon during boiling of the refrigerant dissolved in the refrigerator oil can effectively be suppressed. In the refrigeration system using the refrigerator oil, effective lubrication can be achieved.
Abstract:
Provided is a method of measuring a degree of degradation/alteration of a lubricating oil, including obtaining dielectric constants or electrostatic capacitances at two or more different frequencies and determining a degradation/alteration state of the lubricating oil based on values of the dielectric constants or the electrostatic capacitances, in which one frequency (H1) of the two or more frequencies is in a range of 1 to 100 Hz, and another frequency (H2) is more than the frequency (H1) and in a range of 10,000 Hz or less. Accordingly, it is possible to provide a method of measuring a degree of degradation/alteration of a lubricating oil and a measuring device therefor, which are capable of measuring a degree of degradation of the lubricating oil easily and precisely and predicting a degradation/alteration mechanism of the lubricating oil.
Abstract:
Provided are a method of measuring a degree of degradation of a lubricating oil and a measuring device therefor, in which (a) acidity is measured through use of an ISFET of hydrogen ion sensitive type and (b) dielectric constants or electrostatic capacitances at two or more different frequencies are obtained, to thereby determine a degradation state of the lubricating oil based on the acidity and a plurality of values of the dielectric constants or the electrostatic capacitances. Accordingly, the degree of degradation of the lubricating oil can be measured easily and precisely and a degradation mechanism of the lubricating oil can be predicted.
Abstract:
A lubricating composition comprising a base oil, (A) one or more kinds of compounds selected from phenolic antioxidants and aminic antioxidants, and (B) an ester compound having a disulfide structure is provided. The lubricating composition of the present invention has excellent stability against oxidation, prevents increase of acid value and sludge formation, and has low corrosivity to non-ferrous metals.
Abstract:
An additive for lubricating oils and fuel oils comprising a disulfide compound, as the main component, represented by the general formula (I) R1OOC—CR3R4—CR5(COOR2)—S—S—CR10(COOR7)—CR8R9—COOR6 (I) wherein R1, R2, R6, and R7 each independently represent a hydrocarbyl group having from 1 to 30 carbon atoms and may contain an oxygen, sulfur, or nitrogen atom; and R3 to R5 and R8 to R10 each independently represent a hydrogen atom or hydrocarbyl group having from 1 to 5 carbon atoms, a lubricant oil composition and fuel oil composition comprising the additive are prepared to provide a sulfur-based extreme-pressure additive which exhibits excellent load carrying capacity and wear resistance and corrosion resistance against nonferrous metals and can be used in lubricating oils and fuel oils, and to provide a lubricating oil composition and fuel oil composition containing the additive.
Abstract:
The present invention provides a lubricating oil composition for diesel engines, and more particularly to a lubricating oil composition for diesel engines, which comprises low ashes and no metals, has exceedingly high detergency and excellent antiwear so that it is suitably used for diesel engines equipped with an apparatus for after-treatment of exhaust gas. The lubricating oil composition for diesel engines, of which a lubricating base oil comprises a component (A): 2 to 30% by mass, based on the total amount of the composition, of a succinimide compound having an alkenyl group or an alkyl group of a number average molecular weight of 80 to 500 or a boronic compound thereof, and a component (B): 0.5 to 30% by mass, based on the total amount of the composition, of a succinimide compound having an alkenyl group of a number average molecular weight of 800 to 3,500 or a boronic compound thereof.
Abstract:
A lubricant composition for compression-type refrigerating machines containing tetrafluoroethane or the like as a refrigerant and a lubricant comprising (A) 40 to 95% by weight of a synthetic oil composed of a poly-.alpha.-olefin and/or an ethylene/.alpha.-olefin copolymer or a mixture of an alkylbenzene and a poly-.alpha.-olefin and/or an ethylene/.alpha.-olefin copolymer and (B) 5 to 60% by weight of a fluidity improver composed of both or either of an ester compound and a triglyceride. The lubricant composition is excellent in the performance such as wear resistance, electrical insulating properties, hydrolytic stability, nonhygroscopicity, etc. and also in returnability of the lubricant composition. Thus, the lubricant is especially effective when used in automobile or household air conditioner, refrigerator, etc. having high industrial usefulness.
Abstract:
Provided are a method of measuring a degree of degradation of a lubricating oil and a measuring device therefor, in which (a) acidity is measured through use of an ISFET of hydrogen ion sensitive type and (b) dielectric constants or electrostatic capacitances at two or more different frequencies are obtained, to thereby determine a degradation state of the lubricating oil based on the acidity and a plurality of values of the dielectric constants or the electrostatic capacitances. Accordingly, the degree of degradation of the lubricating oil can be measured easily and precisely and a degradation mechanism of the lubricating oil can be predicted.
Abstract:
Provided is a method of measuring a degree of degradation/alteration of a lubricating oil, including obtaining dielectric constants or electrostatic capacitances at two or more different frequencies and determining a degradation/alteration state of the lubricating oil based on values of the dielectric constants or the electrostatic capacitances, in which one frequency (H1) of the two or more frequencies is in a range of 1 to 100 Hz, and another frequency (H2) is more than the frequency (H1) and in a range of 10,000 Hz or less. Accordingly, it is possible to provide a method of measuring a degree of degradation/alteration of a lubricating oil and a measuring device therefor, which are capable of measuring a degree of degradation of the lubricating oil easily and precisely and predicting a degradation/alteration mechanism of the lubricating oil.
Abstract:
A lube oil composition which is suitably used for diesel engines which exhaust large amounts of sulfur dioxides (Sox). The composition exhibit excellent corrosion/wear preventive properties against SOx. The lube oil composition of the invention for diesel engines includes a lube oil base having a kinematic viscosity of 8-35 mm2/s at 100° C.; a component (A) which is a compound selected from the group consisting of over based sulfonates of alkaline earth metals, over based phenates of alkaline earth metals, and over based salicylates of alkaline earth metals; and a component (B) which is a bis-type succinic imide compound having an absorption ratio, &agr;/&bgr; (wherein &agr; is the intensity of an absorption peak at 1550±10 cm−1 and &bgr; is the intensity of an absorption peak at 1700±10 cm−1), of absorption peaks in an IR spectrum of not more than 0.005.