Base oil for cooling of device, device-cooling oil containing the base oil, device to be cooled by the cooling oil, and device cooling method using the cooling oil

Abstract

A device-cooling base oil includes 30 mass % of at least one of an oleyl ester (e.g., oleate and oleyl alcohol ester) and oleyl ether. The oleyl ester and the oleyl ether each have 23 or more of a total number of a terminal methyl group, a methylene group and an ether group in a main chain and 1 or less of a total number of a methyl branch and an ethyl branch. The base oil has a kinematic viscosity at 40 degrees C. in a range of 4 mm 2 /s to 30 mm 2 /s. A device-cooling oil provided by blending the base oil is excellent in electrical insulation properties and thermal conductivity, and thus is favorably usable for cooling a motor, a battery, an inverter, an engine, an electric cell or the like in an electric vehicle, a hybrid vehicle or the like.

1 . A base oil, comprising 30 mass % or more of at least one of an oleyl ester and an oleyl ether,
 wherein:   the oleyl ester and the oleyl ether each have 23 or more of a total number of a terminal methyl group, a methylene group and an ether group in a main chain;   the oleyl ester and the oleyl ether each have 1 or less of a total number of a methyl branch and an ethyl branch; and   the base oil has a kinematic viscosity in a range of 4 mm 2 /s to 30 mm 2 /s.   
     
     
         2 . The base oil of  claim 1 , comprising 50 mass % or more of the at least one of the oleyl ester and the oleyl ether. 
     
     
         3 . A base oil, comprising 30 mass % or more of at least one of an aliphatic monoester and an aliphatic monoether,
 wherein:   the aliphatic monoester and the aliphatic monoether each have 18 or more of a total number of a terminal methyl group, a methylene group and an ether group in a main chain;   the aliphatic monoester and the aliphatic monoether each have 2 or less of a total number of a methyl branch and an ethyl branch; and   the base oil has a kinematic viscosity in a range of 4 mm 2 /s to 30 mm 2 /s.   
     
     
         4 . The base oil of  claim 3 , wherein at least one of the aliphatic monoester and the aliphatic monoether has a chain structure. 
     
     
         5 . A base oil, comprising 30 mass % or more of at least one of an aliphatic diester and an aliphatic diether,
 wherein:   the aliphatic diester and the aliphatic diether each have 20 or more of a total number of a terminal methyl group, a methylene group and an ether group in a main chain;   the aliphatic diester and the aliphatic diether each have 2 or less of a total number of a methyl branch and an ethyl branch; and   the base oil has a kinematic viscosity in a range of 4 mm 2 /s to 30 mm 2 /s.   
     
     
         6 . A base oil, comprising 30 mass % or more of at least one compound selected from the group consisting of an aliphatic triester, an aliphatic triether, an aliphatic tri(etherester), an aliphatic tetraester, an aliphatic tetraether, an aliphatic tetra(etherester), an aromatic diester, an aromatic diether and an aromatic di(etherester),
 wherein:   each of the at least one compound has 18 or more of a total number of a terminal methyl group, a methylene group and an ether group in a main chain, and 1 or less of a total number of a methyl branch and an ethyl branch; and   the base oil has a kinematic viscosity in a range of 4 mm 2 /s to 30 mm 2 /s.   
     
     
         7 . The base oil of  claim 1 , wherein a thermal conductivity of the base oil at 25 degrees C. is 0.142 W/(m·K) or more. 
     
     
         8 . The base oil of  claim 1 , wherein a volume resistivity of the base oil at 25 degrees C. is 10 10  Ω·cm or more. 
     
     
         9 . A device-cooling oil, comprising the base oil of  claim 1 . 
     
     
         10 . A device configured to be cooled by the device-cooling oil of  claim 9 . 
     
     
         11 . The device of  claim 10 , wherein the device is suitable for an electric vehicle or a hybrid vehicle. 
     
     
         12 . The device of  claim 10 , wherein the device is at least one selected from the group consisting of a motor, a battery, an inverter, an engine and an electric cell. 
     
     
         13 . A device cooling method, comprising contacting a device with the device-cooling oil of  claim 9 . 
     
     
         14 . The device of  claim 11 , wherein the device is at least one selected from the group consisting of a motor, a battery, an inverter, an engine and an electric cell. 
     
     
         15 . The base oil of  claim 3 , wherein a thermal conductivity of the base oil at 25 degrees C. is 0.142 W/(m·K) or more. 
     
     
         16 . The base oil of  claim 3 , wherein a volume resistivity of the base oil at 25 degrees C. is 10 10  Ω·cm or more. 
     
     
         17 . A device-cooling oil, comprising the base oil of  claim 3 . 
     
     
         18 . A device configured to be cooled by the device-cooling oil of  claim 17 . 
     
     
         19 . The device of  claim 18 , wherein the device is suitable for an electric vehicle or a hybrid vehicle. 
     
     
         20 . The device of  claim 18 , wherein the device is at least one selected from the group consisting of a motor, a battery, an inverter, an engine and an electric cell. 
     
     
         21 . A device cooling method comprising contacting a device with the device-cooling oil of  claim 17 . 
     
     
         22 . The device of  claim 19 , wherein the device is at least one selected from the group consisting of a motor, a battery, an inverter, an engine and an electric cell. 
     
     
         23 . The base oil of  claim 5 , wherein a thermal conductivity of the base oil at 25 degrees C. is 0.142 W/(m·K) or more. 
     
     
         24 . The base oil of  claim 5 , wherein a volume resistivity of the base oil at 25 degrees C. is 10 10  Ω·cm or more. 
     
     
         25 . A device-cooling oil, comprising the base oil of  claim 5 . 
     
     
         26 . A device configured to be cooled by the device-cooling oil of  claim 25 . 
     
     
         27 . The device of  claim 26 , wherein the device is suitable for an electric vehicle or a hybrid vehicle. 
     
     
         28 . The device of  claim 26 , wherein the device is at least one selected from the group consisting of a motor, a battery, an inverter, an engine and an electric cell. 
     
     
         29 . A device cooling method, comprising contacting a device with the device-cooling oil of  claim 25 . 
     
     
         30 . The device of  claim 27 , wherein the device is at least one selected from the group consisting of a motor, a battery, an inverter, an engine and an electric cell. 
     
     
         31 . The base oil of  claim 6 , wherein a thermal conductivity of the base oil at 25 degrees C. is 0.142 W/(m·K) or more. 
     
     
         32 . The base oil of  claim 6 , wherein a volume resistivity of the base oil at 25 degrees C. is 10 10  Ω·cm or more. 
     
     
         33 . A device-cooling oil, comprising the base oil of  claim 6 . 
     
     
         34 . A device configured to be cooled by the device-cooling oil of  claim 33 . 
     
     
         35 . The device of  claim 34 , wherein the device is suitable for an electric vehicle or a hybrid vehicle. 
     
     
         36 . The device of  claim 34 , wherein the device is at least one selected from the group consisting of a motor, a battery, an inverter, an engine and an electric cell. 
     
     
         37 . A device cooling method, comprising contacting a device with the device-cooling oil of  claim 33 . 
     
     
         38 . The device of  claim 35 , wherein the device is at least one selected from the group consisting of a motor, a battery, an inverter, an engine and an electric cell.