| abstract |
The present invention addresses the problem of providing a lubricant having excellent lubrication performance. The present invention also addresses the problem of producing a polyester composition which places little burden on the environment and which can be mass-produced. The present invention pertains to a production method for a composite polyester composition in which components having weight average molecular weights of 1300 or lower account for 43% or less of the area of a GPC chart of the composite polyester composition, and the production method includes a step of obtaining a composite polyester composition by condensing in the absence of a solvent a polyhydric alcohol, a polyhydric carboxylic acid, which has 5 or more carbon atoms and which has at least 2 carboxyl groups, and a monohydric alcohol having at least 1 oxyalkylene group. Furthermore, the present invention pertains to a composite polyester composition, a lubricant composition and a lubricant. |