Water-soluble metalworking fluid

Abstract

A water-soluble metalworking fluid that includes a base oil (A) and an ether carboxylic acid (B) represented by general formula (b-1), where A is a C1-4 alkylene group, when multiple A are present, each A may be the same group or may be a different group, B is a single bond or a C1-4 alkylene group, n is an integer of 1-100, and R is a hydrocarbon group. The ether carboxylic acid (B) content is 0.1-10 mass % based on the total amount of the water-soluble metalworking fluid.

1 . A water-soluble metalworking oil, comprising
 a base oil (A); and   an ether carboxylic acid (B) represented by the following formula (b-1), wherein a content of the ether carboxylic acid (B) is 0.1 to 10% by mass based on a total mass of the water-soluble metalworking oil:   
       
         
           
           
               
               
           
         
         
           wherein A is an alkylene group having 1 to 4 carbon atoms, and when a plurality of A are present, each A is the same or different from each other, 
           B is a single bond or an alkylene group having 1 to 4 carbon atoms, 
           n is an integer of 1 to 100, and 
           R is a hydrocarbon group 
         
       
     
     
         2 . The water-soluble metalworking oil according to  claim 1 , wherein B in the formula (b-1) is a methylene group. 
     
     
         3 . The water-soluble metalworking oil according to  claim 1 , wherein the ether carboxylic acid (B) has an HLB of 5.0 or more. 
     
     
         4 . The water-soluble metalworking oil according to  claim 1 , wherein the ether carboxylic acid (B) has an HLB of more than 6.0. 
     
     
         5 . The water-soluble metalworking oil according to  claim 1 , wherein A in the formula (b-1) is an ethylene group. 
     
     
         6 . The water-soluble metalworking oil according to  claim 1 , wherein n in the formula (b-1) is 6 or more. 
     
     
         7 . The water-soluble metalworking oil according to  claim 1 , wherein R in the formula (b-1) is a hydrocarbon group having 10 to 30 carbon atoms. 
     
     
         8 . The water-soluble metalworking oil according to  claim 1 , further comprising a nonionic surfactant (C). 
     
     
         9 . The water-soluble metalworking oil according to  claim 8 , wherein a mass ratio of a content of the nonionic surfactant (C) to a content of the ether carboxylic acid (B) [(C)/(B)] is 1 to 25. 
     
     
         10 . The water-soluble metalworking oil according to  claim 1 , further comprising an amine compound (D). 
     
     
         11 . The water-soluble metalworking oil according to  claim 10 , wherein a mass ratio of a content of the amine compound (D) to a content of the ether carboxylic acid (B) [(D)/(B)] is 1 to 166. 
     
     
         12 . A metalworking fluid, comprising the water-soluble metalworking oil according to  claim 1 . 
     
     
         13 - 14 . (canceled) 
     
     
         15 . A method of working a metal workpiece, the method comprising
 processing the metal workpiece while the metal workpiece is in contact with the metalworking fluid of claim  12 .   
     
     
         16 . The method of  claim 15 , wherein the metalworking fluid of  claim 12  is in contact with an emulsion inhibitor. 
     
     
         17 . The method of  claim 15 , wherein the emulsion inhibitor is grease.