Patent ID: 8642504

Claim:
A composition comprising an oxygen-containing transition metal compound, a base, and an aqueous solvent, wherein the base is at least one of an alkali metal hydroxide, an alkali metal carbonate, an alkaline earth metal hydroxide, an alkaline earth metal carbonate, an ammonium hydroxide, an ammonium carbonate, or an amine of the formula (R 2 R 3 R 4 )N, wherein R 2 , R 3 and R 4 are the same or different, and wherein R 2 , R 3 and R 4 are independently hydrogen, C 1-8 -alkyl or aryl, or wherein R 2 can be hydrogen, C 1-8 -alkyl or aryl and R 3 and R 4 can together with the nitrogen to which they are attached form a 5- or 6-membered cyclic ring, wherein C 1-8 -alkyl and aryl may be mono- or polysubstituted with hydroxyl or amino, wherein the oxygen-containing transition metal compound is at least one of an oxygen-containing chromium, molybdenum or tungsten compound, and wherein the composition is colorless and can form a transparent colorless coating, which can yield markings of high contrast on exposure to energy, and wherein a transparent coating is defined as a coating that has a transmittance of greater than 80% of the visible wavelength, and wherein the composition comprises 10 to 50% by weight of the base based on the weight of the total composition.