ylene glycol and dipropylene glycol, and polyhydric alcohols, such as glycerol, trimethylolpropane, 1,4-cyclohexanedimethanol, hydroxypivalic acidneopentyl glycol ester, 1,4-cyclohexanediol and hydrogenated bisphenol A, or there may be mentioned acrylic polymers having hydroxyl or amino groups in the side chains.