ises an aqueous composition comprising at least one base chosen from mineral bases and organic bases.The pH of the component (C) may range, for example, from 7 to 12 and further, for example, from 8 to 10.The mineral bases used in the composition disclosed herein may, for example, be chosen from at least one of alkali metal and alkaline-earth metal salts, such as sodium hydroxide, potassium hydrox