Water-soluble metalworking oil, and metalworking coolant

Abstract

A water-soluble metalworking fluid of the invention contains a component (A) that is a dicarboxylic acid including a sulfide structure and a component (B) that is a monocarboxylic acid, in which the fluid contains no polyalkylene glycol. A metalworking coolant of the invention is provided by diluting the above-described water-soluble metalworking fluid with water.

1 . A water-soluble metalworking fluid, comprising:
 a component (A), which is a dicarboxylic acid comprising a sulfide structure; and   a component (B), which is a monocarboxylic acid, wherein   the water-soluble metalworking fluid does not comprise polyalkylene glycol.   
     
     
         2 . The water-soluble metalworking fluid according to  claim 1 , wherein the component (A) is a compound of formula (1):
   HOOC—R 1 —S n —R 2 —COOH  (1)
   wherein   R 1  and R 2  are each independently a hydrocarbon group having 1 to 5 carbon atoms, and   n is an integer of from 1 to 8.   
     
     
         3 . The water-soluble metalworking fluid according to  claim 1 , wherein a content of the component (A) is in a range from 0.1 mass % to 14 mass % of a total amount of the fluid. 
     
     
         4 . The water-soluble metalworking fluid according to  claim 1 , wherein the component (B) is a compound of formula (2):
   R 3 —COOH  (2)
   wherein R 3  is a hydrocarbon group having 11 or more carbon atoms.   
     
     
         5 . The water-soluble metalworking fluid according to  claim 1 , wherein a content of the component (B) is in a range from 1 mass % to 20 mass % of the total amount of the fluid. 
     
     
         6 . The water-soluble metalworking fluid according to  claim 1 , further comprising:
 a component (C), which is an acethylene glycol surfactant.   
     
     
         7 . The water-soluble metalworking fluid according to  claim 6 , wherein a content of the component (C) is in a range from 1 mass % to 15 mass % of the total amount of the fluid. 
     
     
         8 . The water-based metalworking fluid according to  claim 1 , wherein the water-based metalworking fluid is in a form of an undiluted solution comprising water in a range from 15 mass % to 75 mass %. 
     
     
         9 . A metalworking coolant, obtained diluting the water-based metalworking fluid according to  claim 1  with water by 2 to 200 times in volume. 
     
     
         10 . The metalworking coolant according to  claim 9 , wherein the metalworking coolant is suitable for grinding.