Coolant composition
A coolant composition includes a mineral oil or a synthetic oil and a surfactant, in which a conductivity of the coolant composition is lower than 0.1 μS/cm, and the surfactant is a nonionic surfactant that is a fatty acid ester having a freezing point of lower than −15° C. and having a cyclic structure.
1 . A coolant composition comprising:
90 mass % of a mineral oil as a base oil;
5 mass % of a sucrose fatty acid ester as a nonionic surfactant, wherein the sucrose fatty acid ester has a freezing point of less than −15° C. and a cyclic structure, and wherein an alkyl group of the fatty acid ester has a linear or branched structure; and
5 mass % of water, wherein the mass % is based on a total mass of the mineral oil, the sucrose fatty acid ester and the water,
wherein an electrical conductivity of the coolant composition is lower than 0.0009 μS/cm, and
a viscosity of the coolant composition at −15° C. is less than 40 mm 2 /s.
2 . The coolant composition according to claim 1 , further comprising one or more selected from an antioxidant, a rust inhibitor, a viscosity index improver, a pour point depressant, a dispersant, a surface active agent, an antiwear additive, a defoamer, or an antistatic fluid.
3 . The coolant composition according to claim 1 , wherein a viscosity of the coolant composition is 10 mm 2 /s or lower at 40° C.