DRYING AND FINISHING AGENT FOR AUTOMATIC DISHWASHER

PROBLEM TO BE SOLVED: To provide a drying and finishing agent having improved performance, by using a polyglycerol fatty acid ester which is obtained by esterification between polyglycerols containing a single polyglycerol having a specific polymerization degree and a fatty acid. SOLUTION: A polyglycerol which has a wide polymerization degree distribution and contains some unreacted materials is subjected to molecular distillation, a vacuum distillation using steam as a carrier gas, liquid chromatography and the like, to remove or reduce reaction products having lower molecular weights than that of a product of a specific polymerization degree. Polyglycerols containing a polyglycerol having a single polymerization degree of n (n is 3, 4 or 5) in an amount of 50 wt.% or more are thus obtained. These polyglycerols are esterificated with a fatty acid having a carbon number of (2n) to (2n+4), thereby providing a drying and finishing agent for an automatic dish washer, which comprises a polyglycerol fatty acid ester having a value of (hydrophilic group chain length/hydrophobia group chain length) of 1.3 to 2.4. This finishing agent is incorporated into rinsing water in an amount of 7.5 to 150 mg/liter.