Any water-soluble solvent may be employed as long as it is soluble in water, and examples include an alkyl alcohol with 1 to 4 carbon atoms such as methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, sec-butyl alcohol, or t-butyl alcohol; an amide such as dimethylformamide or dimethylacetamide; a ketone or a ketoalcohol such as acetone or diacetone alcohol; an ethe