Patent ID: 8361587
Filing Date: 2013-01-29
Classification: C09D,G11B

Abstract:
1. An optical article comprising: a primary mark and a secondary mark disposed on a data storage region of an optical data layer; wherein the primary mark comprises a first optical-state change material and the secondary mark comprises a second optical-state change material; wherein the optical article is configured to be transformed from a pre-activated state to an activated state when a localized authorized activation method is selectively applied to the primary mark and not to the secondary mark resulting in the first optical-state change material changing from opaque to transparent; and wherein the optical article is configured to be transformed from the pre-activated state to a deactivated state when a non-localized unauthorized activation method is applied to the secondary mark along with the primary mark resulting in the first optical-state change material changing from opaque to transparent and the second optical-state change material changing from transparent to opaque; wherein the primary mark or the secondary mark is disposed using a thermochromic ink composition comprising a halochromic optical-state change material, at least one base, at least one solvent, and at least one binder material; wherein the pH of the thermochromic ink composition is such that the halochromic optical-state change material remains in its basic state until it is acted upon by a thermal stimulus; and wherein the thermochromic ink composition is capable of transforming from a first optical state to a second optical state upon a change in pH caused by exposure to a thermal stimulus.