Examples of the humectant include lower alcohol such as methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, sec-butyl alcohol, tert-butyl alcohol and the like; amide such as dimethylformamide, dimethylacetamide and the like; ketone such as acetone and the like; ketoalcohol such as diacetone alcohol and the like; ether such as tetrahydrofuran, dioxane and the like;