Patent ID: 8828373

Claim:
A polyalkylene glycol derivative comprising a compound of the formula (1): wherein R is a hydrocarbon group having 1 to 24 carbon atoms, OA 1 and OA 2 are each an oxyalkylene group having 2 to 4 carbon atoms, the groups represented by R are the same or different from each other in one molecule, the groups represented by OA 2 are the same or different from each other in one molecule, m and n each is an average number of moles of the above oxyalkylene group added, m represents 10 to 1000, n represents 1 to 1000, X represents a functional group capable of chemically reacting with a residual group selected from the group selected from the group (I): Group (I) wherein Z represents an alkylene group alone or an alkylene group containing an ether bond, an ester bond, a urethane bond, an amide bond, a carbonate bond, or a secondary amino group and W′ is a halogen atom selected from Cl, Br, and I, and Y is a linker and represents an ether bond, an amide bond, a urethane bond, an ester bond, a secondary amino group, a carbonate bond, or an alkylene group containing these bonds, polydispersity Mw/Mn of the above polyalkylene glycol derivative in gel permeation chromatography satisfying the following relationship: Mw/Mn<1.08 wherein Mw represents a weight average molecular weight and Mn represents a number average molecular weight.