Gasoline engine lubricant oil composition and manufacturing method therefor

Abstract

Provided is a lubricating oil composition capable of revealing fuel consumption reducing properties due to a friction reducing effect within a short period of time while having excellent fuel consumption reducing properties, specifically a lubricating oil composition of the present invention includes a base oil, a molybdenum dithiocarbamate, a calcium detergent, a magnesium detergent, and a boron-free succinimide, wherein the content of the molybdenum dithiocarbamate as converted into a molybdenum atom is 1,200 ppm by mass or less on a basis of the whole amount of the composition; the content of the boron-free succinimide as converted into a nitrogen atom is less than 1,200 ppm by mass on a basis of the whole amount of the composition; and a mass ratio of the molybdenum atom (Mo) to a magnesium atom (Mg) of the magnesium detergent [Mo/Mg] is 0.1 or more.

1 : A lubricating oil composition, comprising:
 a base oil;   a molybdenum dithiocarbamate;   a calcium detergent;   a magnesium detergent; and   a boron-free succinimide,   wherein:   a content of the molybdenum dithiocarbamate as converted into a molybdenum atom is 1,200 ppm by mass or less on a basis of a whole amount of the lubricating oil composition;   a content of the boron-free succinimide as converted into a nitrogen atom is less than 1,200 ppm by mass on a basis of the whole amount of the lubricating oil composition; and   a mass ratio of the molybdenum atom (Mo) to a magnesium atom (Mg) of the magnesium detergent [Mo/Mg] is 0.1 or more.   
     
     
         2 : The lubricating oil composition according to  claim 1 , wherein a content of the calcium detergent as converted into a calcium atom is 2,000 ppm by mass or less on a basis of the whole amount of the composition. 
     
     
         3 : The lubricating oil composition according to  claim 1 , further comprising:
 a boron-containing succinimide,   wherein a content of the boron-containing succinimide as converted into a boron atom being 50 ppm by mass or more on a basis of the whole amount of the lubricating oil composition.   
     
     
         4 : The lubricating oil composition according to  claim 1 , further comprising:
 a poly(meth)acrylate-based viscosity index improver.   
     
     
         5 : The lubricating oil composition according to  claim 1 , wherein the content of the molybdenum dithiocarbamate as converted into a molybdenum atom is 60 to 1,200 ppm by mass on a basis of the whole amount of the lubricating oil composition. 
     
     
         6 : The lubricating oil composition according to  claim 1 , wherein the content of the molybdenum dithiocarbamate as converted into a molybdenum atom is 100 to 1,100 ppm by mass on a basis of the whole amount of the lubricating oil composition. 
     
     
         7 : The lubricating oil composition according to  claim 1 , wherein the content of the molybdenum dithiocarbamate as converted into a molybdenum atom is 300 to 1,100 ppm by mass on a basis of the whole amount of the lubricating oil composition. 
     
     
         8 : The lubricating oil composition according to  claim 1 , wherein a content of the calcium detergent as converted into a calcium atom is 1,000 to 2,000 ppm by mass on a basis of the whole amount of the lubricating oil composition. 
     
     
         9 : The lubricating oil composition according to  claim 1 , which does not include a sodium detergent. 
     
     
         10 : The lubricating oil composition according to  claim 1 , wherein the base oil is at least one selected from a mineral oil and a synthetic oil which are classified into Groups 3 to 5 of the base stock categories of the API (American Petroleum Institute). 
     
     
         11 : The lubricating oil composition according to  claim 1 , which has a kinematic viscosity at 100° C. of 3.8 to 12.5 mm 2 /s. 
     
     
         12 : The lubricating oil composition according to  claim 1 , which is adapted to function as a lubricating oil composition for a gasoline engine. 
     
     
         13 : A method for producing a lubricating oil composition, the method comprising blending a base oil with
 a molybdenum dithiocarbamate,   a calcium detergent,   a magnesium detergent, and   a boron-free succinimide,   such that   a content of the molybdenum dithiocarbamate as converted into a molybdenum atom is 1,200 ppm by mass or less on a basis of a whole amount of the lubricating oil composition,   a content of the boron-free succinimide as converted into a nitrogen atom is less than 1,200 ppm by mass on a basis of the whole amount of the lubricating oil composition, and   a mass ratio of the molybdenum atom (Mo) to a magnesium atom (Mg) of the magnesium detergent [Mo/Mg] is 0.1 or more.