UV cured indicating devices
AssigneeJP Laboratories, Inc.
InventorGordhanbhai N Patel
Life of this patent
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Abstract
This invention relates to thin indicating devices, such as time-temperature indicators and a method of making by applying and UV curing one or more layers of indicating composition are disclosed. For example, an indicator layer is applied on substrate and cured with UV light, immediately followed by an application of an activator layer which is cured by UV light. The device can have other layers, such as a permeable barrier between the activator and indicator layer and a top protective layers which are also UV cured. This fast curing method prevents premature reactions, e.g., diffusion of activator into indicator layer and vice versa during manufacturing.
Claims15
A method of making a composite time-temperature indicating device by:
- (i) applying an indicator layer comprised of at least one UV curable binder and at least one indicator to a substrate;
- (ii) curing the UV curable binder of the indicator layer with UV light to form a cured indicator layer;
- (iii) applying an activator layer comprised of at least one UV curable binder and at least one activator on the indicator layer wherein said activator can react with said indicator after an induction period;
- (iv) curing the activator layer with UV light after said applying said activator layer on said indicator layer to form a cured activator layer;
- (v) applying a UV curable protective layer on the cured activator layer;
- and
- (vi) UV curing the protective layer.
A method of making a composite time-temperature indicating device by:
- applying an indicator layer comprised of at least one UV curable binder and at least one indicator to a substrate;
- applying an activator layer comprising at least one UV curable binder and at least one activator to the indicator layer wherein said activator can react with said indicator after an induction period
- curing the activator layer and the indicator layer with UV light;
- applying a UV curable protective layer on the cured activator layer;
- and
- UV curing the protective layer.
A time-temperature indicating device comprised of a substrate having thereon:
- (i) an indicator layer comprised of at least one UV cured binder and at least one indicator;
- ii) an activator layer comprised of at least one UV cured binder and at least one activator cured onto said indicator layer wherein said activator can react with said indicator after an induction period;
- and
- (iii) a protective layer.
A time-temperature indicating device comprised of a substrate having thereon a layer comprising a UV cured binder comprising solid particles of an indicator in an indicator layer and solid particles of an activator in an activator layer wherein said activator layer is cured onto said indicator layer and wherein said activator can react with said indicator after an induction period.
A time-temperature indicating device comprised of a substrate having thereon:
- (i) an indicator layer comprised of at least one UV cured binder and at least one indicator;
- (ii) a permeable layer cured onto said indicator layer;
- (iii) an activator layer comprised of at least one UV cured binder and at least one activator cured onto said permeable layer wherein said activator can react with said indicator after an induction period;
- and
- (iv) a protective layer cured on said activator layer.
A time-temperature indicating device comprised of a substrate having thereon:
- (i) an indicator layer comprising at least one UV cured binder and at least one indicator and a permeable layer;
- (ii) an activator layer comprised of at least one UV cured binder and at least one activator cured onto said permeable layer wherein said activator can react with said indicator after an induction period;
- and
- (iii) a protective layer cured onto said activator layer.
Dependencies are inferred from the claim text.