Examples of the polyhydric alcohols are glycols, such as ethylene glycol, propylene glycol, 1,3-butylene diol, 1,6-hexane diol, diethylene glycol, neopentyl glycol, triethylene glycol and the like; hydrogenated bisphenol A; bisphenol dihydroxypropyl ether; glycelol; trimethylolethane; trimethylolpropane; pentaerythritol; and a mixture thereof.