Working fluid for brittle material and working fluid for hard material

Abstract

Provided is a water-containing working fluid for a brittle material and a hard material, which includes (A) water, (B) a water soluble polymeric compound having an oxygen-containing group and a number average molecular weight of 6,000 to 3,000,000, and (C) a nonionic surfactant having a clouding point of 10 to 70° C. in a 1% by mass aqueous solution. In a loose-abrasive grain method, the working fluid allows a slurry thereof to be supplied into the working gap sufficiently and has excellent abrasive grain dispersion stability and excellent properties to wash and disperse cutting swarf. In a method using a fixed-abrasive grain wire saw, the working fluid rarely causes detachment of the fixed abrasive grains and has excellent properties to wash and disperse cutting swarf.

1 . A working fluid, comprising,
 (A) water;   (B) a water soluble polymeric compound comprising an oxygen-comprising group and having a number average molecular weight of 6,000 to 3,000,000; and   (C) a nonionic surfactant having a clouding point of 10 to 70° C. in a 1% by mass aqueous solution.   
     
     
         2 . The working fluid of  claim 1 , wherein the oxygen-comprising group of the component water soluble polymeric compound (B) is selected from the group consisting of a carboxyl group, a hydroxyl group, an oxyethylene group and an oxypropylene group. 
     
     
         3 . The working fluid of  claim 1 , wherein the water soluble polymeric compound (B) is at least one selected from the group consisting of a carboxylic acid-based polymeric compound and an alkylene glycol-based polymeric compound. 
     
     
         4 . The working fluid of  claim 3 , wherein the water soluble polymeric compound (B) is a combination of the carboxylic acid-based polymeric compound and the alkylene glycol-based polymeric compound. 
     
     
         5 . The working fluid of  claim 1 , wherein the nonionic surfactant (C) comprises an oxypropylene group and has a number average molecular weight of 70 to 5,000. 
     
     
         6 . The working fluid of  claim 1 , wherein
 a content of the water (A) is 50 to 99% by mass,   a content of the water soluble polymeric compound (B) is 0.01 to 30% by mass, and   a content of the nonionic surfactant (C) is 0.1 to 20% by mass,   based on a total amount of the working fluid.   
     
     
         7 . The working fluid of  claim 1 , wherein the working fluid has a pH of 2 to 10. 
     
     
         8 . The working fluid of  claim 7 , wherein the working fluid comprises an acid component and an alkaline component, and wherein the pH is adjusted by controlling a blending ratio of the acid component and the alkaline component. 
     
     
         9 . The working fluid of  claim 2 , wherein the water soluble polymeric compound (B) is at least one selected from the group consisting of a carboxylic acid-based polymeric compound and an alkylene glycol-based polymeric compound. 
     
     
         10 . The working fluid of  claim 9 , wherein the water soluble polymeric compound (B) is a combination of the carboxylic acid-based polymeric compound and the alkylene glycol-based polymeric compound. 
     
     
         11 . The working fluid of  claim 2 , wherein the nonionic surfactant (C) comprises an oxypropylene group and has a number average molecular weight of 70 to 5,000. 
     
     
         12 . The working fluid of  claim 3 , wherein the nonionic surfactant (C) comprises an oxypropylene group and has a number average molecular weight of 70 to 5,000. 
     
     
         13 . The working fluid of  claim 4 , wherein the nonionic surfactant (C) comprises an oxypropylene group and has a number average molecular weight of 70 to 5,000. 
     
     
         14 . The working fluid of  claim 2 , wherein
 a content of the water (A) is 50 to 99% by mass,   a content of the water soluble polymeric compound (B) is 0.01 to 30% by mass, and   a content of the nonionic surfactant (C) is 0.1 to 20% by mass,   based on a total amount of the working fluid.   
     
     
         15 . The working fluid of  claim 3 , wherein
 a content of the water (A) is 50 to 99% by mass,   a content of the water soluble polymeric compound (B) is 0.01 to 30% by mass, and   a content of the nonionic surfactant (C) is 0.1 to 20% by mass,   based on a total amount of the working fluid.   
     
     
         16 . The working fluid of  claim 4 , wherein
 a content of the water (A) is 50 to 99% by mass,   a content of the water soluble polymeric compound (B) is 0.01 to 30% by mass, and   a content of the nonionic surfactant (C) is 0.1 to 20% by mass,   based on a total amount of the working fluid.   
     
     
         17 . The working fluid of  claim 5 , wherein
 a content of the water (A) is 50 to 99% by mass,   a content of the water soluble polymeric compound (B) is 0.01 to 30% by mass, and   a content of the nonionic surfactant (C) is 0.1 to 20% by mass,   based on a total amount of the working fluid.   
     
     
         18 . The working fluid of  claim 2 , wherein the working fluid has a pH of 2 to 10. 
     
     
         19 . The working fluid of  claim 3 , wherein the working fluid has a pH of 2 to 10. 
     
     
         20 . The working fluid of  claim 4 , wherein the working fluid has a pH of 2 to 10.