| abstract |
A method of imparting colour to a plastic substrate comprising applying to the substrate, or incorporating within the substrate, a diacetylene compound of general formula (I) wherein n = 1 to 20; R 1 = an optionally substituted C 1-20 alkyl group which may contain heteroatoms; T = H, an optionally substituted C 1-20 alkyl group which may contain heteroatoms or -(CH 2 ) m -C(=O)-Q 2 R 2 ; Q 1 = NH, CO, NHCONH, OCONH, COS, NHCSNH or NR 3 , wherein m, Q 2 and R 2 are independently selected from the same groups as n, Q 1 and R 1 respectively; R 3 is an optionally substituted C 1-20 alkyl group which may contain heteroatoms; and irradiating the substrate to impart colour to the substrate. |