Abstract: A heat-treatment oil composition contains (A) a first base oil with a kinematic viscosity at 40 degrees C. in a range of 5 mm2/s to 60 mm2/s in an amount of 50 mass % to 95 mass % of a total amount of the composition, (B) a second base oil with a kinematic viscosity at 40 degrees C. of 300 mm2/s or more in an amount of 5 mass % to 50 mass %, and (C) an alpha-olefin copolymer. The heat-treatment oil composition according to the invention can reduce distortion unevenness and hardness unevenness accompanying mass-quenching.

Abstract: A heat-treatment oil composition contains (A) a first base oil with a kinematic viscosity at 40 degrees C. in a range of 5 mm2/s to 60 mm2/s in an amount of 50 mass % to 95 mass % of a total amount of the composition, (B) a second base oil with a kinematic viscosity at 40 degrees C. of 300 mm2/s or more in an amount of 5 mass % to 50 mass %, and (C) an alpha-olefin copolymer. The heat-treatment oil composition according to the invention can reduce distortion unevenness and hardness unevenness accompanying mass-quenching.

Abstract: The present invention relates to a recycling feed apparatus for thinner which serves for purifying a used thinner recovered from a coating treatment process to control a concentration of impurities in the thinner within an adequate range, and recycling the thinner to the coating treatment process, wherein the concentration of the impurities can be detected at a high accuracy, thereby not only enabling feed of the thinner whose concentration is fully controlled but also enhancing a recovery rate of the thinner.

Abstract: Apparatus for producing a polishing solution composed of pure water and abrasive grains, the apparatus including a preparation tank to prepare a polishing solution containing abrasive grains at a predetermined concentration, by mixing an abrasive grain-containing slurry and pure water, and a circulation device for circulating the thus prepared polishing solution to keep the solution in a suspended state. The circulation device includes a circulation conduit and a flow-controllable bypass conduit fluidly associated with the circulation conduit providing a constant flow rate and having a light-extinction type particle detector for monitoring the polishing solution so as to detect large abrasive grains having a particle size not less than a predetermined value and measure the number of the large abrasive grains.

Abstract: The present invention relates to an apparatus for producing a polishing solution mainly comprising pure water and abrasive grains, which apparatus comprises:

Abstract: The present invention relates to a method for diluting an acid or alkaline stock solution with pure water to prepare a mixed solution of an aimed concentration, which method comprises:an initial preparation step A, in which the prescribed amounts of a stock solution and pure water are mixed to prepare a mixed solution with a concentration different from the preset target concentration;a concentration measuring step B, in which the concentration of the mixed solution is measured by the potentiometric titration method; anda preparation step C, in which the deficiency of the stock solution or pure water is calculated on the basis of the difference between the value of concentration measured in the step B and the value of target concentration, and 70 to 99% of the calculated deficiency of the stock solution or pure water is supplied to the mixed solution,the said steps B and C being repeated until the measured value of concentration falls within the range of the threshold of the preset target concentration.

Abstract: A coupling device intended to prevent impurities such as dust and particles adhering to the end face of a solution supplying male pipe 2 from being mixed with a high purity chemical solution N, which will be supplied through the device, not to degrade the purity of the solution. It includes a check valve 7 arranged in that end portion of a solution passage 5 in the male pipe 2 which is inserted into a cleaning chamber 15, a valve pusher 44a arranged in that end portion of a solution passage 43 in a solution supplied female pipe 3 which is connected to the passage 5 in the male pipe 2 to push the check valve 7 to open the passage 5, a valve system for opening and closing the passage 43 when the female pipe 3 is reciprocated in the axial direction, and a check valve 51 located on the outlet side of a cleaning liquid passage 48.