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US 5,965,495 AGranted
Lubricating oil composition for internal combustion engines
AssigneeIdemitsu Kosan Co., Ltd.
InventorsMasahisa Goto, Tomomi Miyaji
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AssigneeIdemitsu Kosan Co., Ltd.
InventorsMasahisa Goto, Tomomi Miyaji
Estimating the term…
A lubricating oil composition for internal combustion engines which comprises a base oil, (a) an ashless dispersant containing boron, (b) a metallic detergent, and optionally (c) at least one selected from a group consisting of esters of aromatic carboxylic acids having hydroxyl group and hydroxy compounds and compounds containing boron which are derived from the esters, wherein a ratio [B]/[M] of a content of boron [B] in the composition in % by weight to a total content of metals [M] derived from the detergent in the composition in % by weight is not less than 0.15, and a sulfated ash content in the composition is not more than 1.5% by weight. The lubricating oil composition has a low ash content, does not show adverse effects on the performance of apparatuses for exhaust gas treatment, and exhibits excellent resistance to coking and oxidation stability.
A lubricating oil composition for internal combustion engines which comprises a base oil, (a) an ashless dispersant containing boron, and (b) a metallic detergent which is comprised of a mixture of at least one compound selected from the group consisting of alkali metal salicylates and alkaline earth metal salicylates and at least one compound selected from the group consisting of alkali metal phenates, alkaline earth metal phenates, alkali metal sulfonates, and alkaline earth metal sulfonates, wherein a ratio [B]/[M] of a content of boron [B] in the composition in % by weight to a total content of metals [M] derived from the metallic detergent in the composition in % by weight is not less than 0.15, and a sulfated ash content in the composition is not more than 1.5% by weight.
A lubricating oil composition for internal combustion engines which comprises a base oil, (a) an ashless dispersant containing boron, (b) a metallic detergent, and (c) at least one selected from a group consisting of esters of aromatic carboxylic acids having hydroxyl group and hydroxy compounds and compounds containing boron which are derived from the esters, wherein a ratio [B]/[M] of a content of boron [B] in the composition in % by weight to a total content of metals [M] derived from the detergent in the composition in % by weight is not less than 0.15, and a sulfated ash content in the composition is not more than 1.5% by weight.
Dependencies are inferred from the claim text.