US Patent 9068051 Method for producing refined polyrotaxane

The present invention aims to provide a method for producing a refined polyrotaxane which includes an industrially advantageous method of producing a polyrotaxane that has excellent storage stability. The method for producing a refined polyrotaxane includes the step of heat-cleaning a polyrotaxane with a cleaning medium, the polyrotaxane containing cyclodextrin molecules, a polyethylene glycol which is included in the cavities of the cyclodextrin molecules in a skewered manner, and a capping group that is placed at each end of the polyethylene glycol and prevents dissociation of the cyclodextrin molecules from the polyethylene glycol.