Abstract:
In one embodiment, a limited play optical storage medium for data comprises: a reflective layer (8), a control portion comprising an optically transparent polymeric resin and a light absorbing material, wherein the control portion has a light transmission of greater than or equal to about 70% at 650 nm, a curing index of greater than or equal to about 0.1 and a filtration index of greater than or equal to about 2.5, and wherein the light absorbing material has a minimum extinction coefficient (measured in CH2C12 solution) at 600 nm of greater than or equal to 1,500 mol-1 cm-1 L, a maximum extinction coefficient (measured in CH2C12 solution) at 650 nm of less than about 1,000 mol-1 cm-1 L, a ratio of extinction coefficient at 650 nm to 600 nm less than about 0.1, and a reactive layer (9) disposed between the reflective layer (8) and the control portion, wherein the reactive layer (9) is designed to limit the time during which data on the medium (disposed on a side of the reactive layer (9) opposite the control portion), can be accessed after exposure to oxygen.