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 method of evaluation a degree of degradation of a lubricating oil, comprising: using a device for evaluating a degree of degradation of a lubricating oil, the device comprising a pH-ISFET which is free from a reference electrode; and measuring a current flowing between a drain and a source of the pH-ISFET with a first circuit wherein a constant voltage is applied between the drain and the source, or measuring a voltage between a drain and a source with a second circuit wherein a constant current is caused to flow between the drain and the source.

Abstract: A lubricating oil composition for diesel engines, particularly a composition with low ashes and no metals. The lubricating oil composition 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 contains a lubricating base oil which includes 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 lubricating oil composition for diesel engines, particularly a composition with low ashes and no metals. The lubricating oil composition 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 contains a lubricating base oil which includes 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: 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 to a fuel oil for a Diesel engine having a Diesel particulate filter (DPF), which comprises a molybdenum compound and having the function of improving the combustion property of a particulate matter (PM) trapped with DPF; a fuel oil comprising the additive; a lubricating oil composition for a Diesel engine having DPF, which has a sulfated ash content of 1.0% by weight or smaller, a sulfur content of 0.3% by weight or smaller and a molybdenum content of 100 ppm or greater; and DPF for removing PM in combustion gas discharged from a Diesel engine vehicle by trapping and burning PM, DPF comprising a filter supporting a molybdenum compound. The combustion property of PM trapped with the filter of DPF is improved, PM is burned at a low temperature with stability, the efficiency of removal of PM is improved and the life of DPF is increased.

Abstract: Provided are a device for evaluating a degree of degradation of a lubricating oil, a method of evaluating a degree of degradation of a lubricating oil, and an on-line lubricating oil management device, which are capable of measuring the degree of degradation of the lubricating oil in a simple and stable manner. The device for evaluating a degree of degradation of a lubricating oil, the method of evaluating a degree of degradation of a lubricating oil, and the on-line lubricating oil management device using the device and the method use a pH-ISFET, and make a determination as to a state of degradation of the lubricating oil through measurement of a change in hydrogen concentration of the lubricating oil by using, as an output, a change in current flowing between a drain and a source in a case where a constant voltage is applied between the drain and the source or a change in voltage between the drain and the source in a case where a constant current is caused to flow between the drain and the source.

Abstract: Processes for producing disulfide compounds that are useful as additives for lubricating oils and fuel oils comprising a disulfide compound, as the main component, is provided.

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 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 to a fuel oil for a Diesel engine having a Diesel particulate filter (DPF), which comprises a molybdenum compound and having the function of improving the combustion property of a particulate matter (PM) trapped with DPF; a fuel oil comprising the additive; a lubricating oil composition for a Diesel engine having DPF, which has a sulfated ash content of 1.0% by weight or smaller, a sulfur content of 0.3% by weight or smaller and a molybdenum content of 100 ppm or greater; and DPF for removing PM in combustion gas discharged from a Diesel engine vehicle by trapping and burning PM, DPF comprising a filter supporting a molybdenum compound. The combustion property of PM trapped with the filter of DPF is improved, PM is burned at a low temperature with stability, the efficiency of removal of PM is improved and the life of DPF is increased.

Abstract: The invention provides a lubricating oil additive for internal combustion engines which additive enables to prepare a lubricating oil composition for internal combustion engines having an enhanced base number without impairing the performance of an exhaust gas treatment apparatus such as a PM trap or an oxidation catalyst member; a lubricating oil additive composition for internal combustion engines; and a lubricating oil composition for internal combustion engines containing the lubricating oil additive composition.

Abstract: An additive to a fuel oil for a Diesel engine having a Diesel particulate filter (DPF), which comprises a molybdenum compound and having the function of improving the combustion property of a particulate matter (PM) trapped with DPF; a fuel oil comprising the additive; a lubricating oil composition for a Diesel engine having DPF, which has a sulfated ash content of 1.0% by weight or smaller, a sulfur content of 0.3% by weight or smaller and a molybdenum content of 100 ppm or greater; and DPF for removing PM in combustion gas discharged from a Diesel engine vehicle by trapping and burning PM, DPF comprising a filter supporting a molybdenum compound. The combustion property of PM trapped with the filter of DPF is improved, PM is burned at a low temperature with stability, the efficiency of removal of PM is improved and the life of DPF is increased.

Abstract: An additive to a fuel oil for a Diesel engine having a Diesel particulate filter (DPF), which comprises a molybdenum compound and having the function of improving the combustion property of a particulate matter (PM) trapped with DPF; a fuel oil comprising the additive; a lubricating oil composition for a Diesel engine having DPF, which has a sulfated ash content of 1.0% by weight or smaller, a sulfur content of 0.3% by weight or smaller and a molybdenum content of 100 ppm or greater; and DPF for removing PM in combustion gas discharged from a Diesel engine vehicle by trapping and burning PM, DPF comprising a filter supporting a molybdenum compound. The combustion property of PM trapped with the filter of DPF is improved, PM is burned at a low temperature with stability, the efficiency of removal of PM is improved and the life of DPF is increased.

Abstract: Provided are novel succinimide compounds obtained by reacting a polyamine having a carbon/nitrogen weight ratio of from 0.85 to 1.25 with a succinic acid compound in a molar ratio to the polyamine of up to 1.40; a process for producing them; a lubricating oil additive containing the compound; and a lubricating oil composition for internal combustion engines which comprises a lube base oil, (a) at least one compound selected from the group consisting of overbased sulfonates, phenates and salicylates with alkaline earth metals, and (b) the succinimide compound, and which has a total base number of from 30 to 150 mg-KOH/g. The composition is for use in internal combustion engines that may discharge a large amount of sulfur oxides (SOx), having the advantage of good corrosion resistance against SOx to be discharged in large quantities.

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.