Lubricant oil composition for spark ignition type internal combustion engine, method for producing lubricant oil composition, spark ignition type internal combustion engine using lubricant oil composition, and method for lubricating internal combustion engine

Abstract

Provided are a lubricating oil composition for internal combustion engine capable of preventing a deterioration of the combustion state of a spark-ignition internal combustion engine, specifically, a lubricating oil composition to be used for a spark-ignition internal combustion engine in which a total tension per piston of tensions applied to the piston ring is 100 N or less, the lubricating oil composition being a lubricating oil composition including a base oil, (A) a calcium-based detergent, at least one selected from (B1) a sodium-based additive and (B2) a magnesium-based additive, and (C) an ash-free sulfur-based additive in predetermined contents; a method for producing the lubricating oil composition; a spark-ignition internal combustion engine using the lubricating oil composition; and a method for lubricating the internal combustion engine.

1 : A lubricating oil composition, comprising:
 a base oil;   (A) a calcium-based detergent;   (B) at least one of (B1) a sodium-based additive and (B2) a magnesium-based additive; and   (C) an ash-free sulfur-based additive,   wherein:   a content of the calcium-based detergent (A) as expressed in terms of a calcium atom content is 0.15% by mass or less on a basis of a total amount of the lubricating oil composition;   a sum total of a content of the sodium-based additive (B1), as expressed in terms of a sodium atom content, and a content of the magnesium-based additive (B2), as expressed in terms of a magnesium atom content, is 0.2% by mass or less on a basis of the total amount of the lubricating oil composition; and   a content of the ash-free sulfur-based additive (C) as expressed in terms of a sulfur atom content is 0.01% by mass or more on a basis of the total amount of the lubricating oil composition.   
     
     
         2 : The lubricating oil composition according to  claim 1 , wherein a NOACK volatile loss of the lubricating oil composition is 10% by mass or more. 
     
     
         3 : The lubricating oil composition according to  claim 1 , wherein the calcium-based detergent (A) is a calcium-based detergent having a base number of 10 to 600 mgKOH/g. 
     
     
         4 : The lubricating oil composition according to  claim 1 , wherein the sodium-based additive (B1) is a sodium-based detergent having a base number of 10 to 600 mgKOH/g. 
     
     
         5 : The lubricating oil composition according to  claim 1 , wherein the magnesium-based additive (B2) is a magnesium-based detergent having a base number of 10 to 600 mgKOH/g. 
     
     
         6 : The lubricating oil composition according to  claim 1 , further comprising:
 (D) an organic molybdenum-based additive,   
       wherein a content of the molybdenum-based additive (D) is 0.005 to 0.20% by mass as expressed in terms of a molybdenum atom content on a basis of the total amount of the lubricating oil composition. 
     
     
         7 : The lubricating oil composition according to  claim 1 , which has a sulfated ash content of 1.0% by mass or less on a basis of the total amount of the composition. 
     
     
         8 : The lubricating oil composition according to  claim 1 , wherein:
 the content of the calcium-based detergent (A) as expressed in terms of a calcium atom content is from 0.05 to 0.15% by mass on the basis of the total amount of the lubricating oil composition; and   a mass ratio of the magnesium atom (Mg), the sodium atom (Na), or both, to the calcium atom (Ca) is from 0.03 to 3.5.   
     
     
         9 : The lubricating oil composition according to  claim 1 , further comprising:
 at least one additive for lubricating oil selected from the group consisting of a viscosity index improver, a dispersant, an anti-wear agent, an extreme pressure agent, a non-sulfur-based antioxidant, and a defoaming agent.   
     
     
         10 : The lubricating oil composition according to  claim 1 , wherein the lubricating oil composition is adapted to function as a lubricating oil composition for a spark-ignition internal combustion gasoline engine. 
     
     
         11 : A method for producing a lubricating oil composition, the method comprising:
 blending a base oil with
 (A) a calcium-based detergent, 
 (B) at least one of (B1) a sodium-based additive and (B2) a magnesium-based additive, and 
 (C) an ash-free sulfur-based additive, in such a manner that: 
   a content of the calcium-based detergent (A) as expressed in terms of a calcium atom content is 0.15% by mass or less on a basis of a total amount of the lubricating oil composition;   a sum total of a content of the sodium-based additive (B1), as expressed in terms of a sodium atom content, and a content of the magnesium-based additive (B2), as expressed in terms of a magnesium atom content, is 0.2% by mass or less on a basis of the total amount of the lubricating oil composition; and   a content of the ash-free sulfur-based additive (C) as expressed in terms of a sulfur atom content is 0.01% by mass or more on a basis of the total amount of the lubricating oil composition.   
     
     
         12 : A spark-ignition internal combustion engine in which a total tension per piston of tensions applied to the piston ring is 100 N or less, the spark-ignition internal combustion engine comprising a lubricating oil composition, said composition comprising:
 a base oil;   (A) a calcium-based detergent;   (B) at least one of (B1) a sodium-based additive and (B2) a magnesium-based additive; and   (C) an ash-free sulfur-based additive,   wherein:   a content of the calcium-based detergent (A) as expressed in terms of a calcium atom content is 0.15% by mass or less on a basis of a total amount of the lubricating oil composition;   a sum total of a content of the sodium-based additive (B1), as expressed in terms of a sodium atom content, and a content of the magnesium-based additive (B2), as expressed in terms of a magnesium atom content, is 0.2% by mass or less on a basis of the total amount of the lubricating oil composition; and   a content of the ash-free sulfur-based additive (C) as expressed in terms of a sulfur atom content is 0.01% by mass or more on a basis of the total amount of the lubricating oil composition.   
     
     
         13 : A method for lubricating a spark-ignition internal combustion engine, the method comprising lubricating the spark-ignition internal combustion engine with a lubricating oil composition comprising:
 a base oil;   (A) a calcium-based detergent;   (B) at least one of (B1) a sodium-based additive and (B2) a magnesium-based additive; and   (C) an ash-free sulfur-based additive,   wherein:   a content of the calcium-based detergent (A) as expressed in terms of a calcium atom content is 0.15% by mass or less on a basis of a total amount of the lubricating oil composition;   a sum total of a content of the sodium-based additive (B1), as expressed in terms of a sodium atom content, and a content of the magnesium-based additive (B2), as expressed in terms of a magnesium atom content, is 0.2% by mass or less on a basis of the total amount of the lubricating oil composition; and   a content of the ash-free sulfur-based additive (C) as expressed in terms of a sulfur atom content is 0.01% by mass or more on a basis of the total amount of the lubricating oil composition.   
     
     
         14 : The lubricating oil composition of  claim 1 , which is adapted to function as a lubricating oil composition for a spark-ignition internal combustion engine in which a total tension per piston of tensions applied to the piston ring is 100 N or less.