IMPACT INDICATOR COATINGS AND METHODS
Impact indicator compositions, application devices, and methods comprising coating a surface to be impacted, wherein the coating comprises microcapsules having a cross-linked polyurea shell and a core surrounded by the shell, the core comprising at least one color former; and a developer capable of activating the color former when in contact therewith.
1 . An impact indicator composition, comprising:
microcapsules having a cross-linked polyurea shell and a core surrounded by the shell, wherein the polyurea shell comprises at least one isocyanate and at least one polyamine, and the core comprises at least one color former; and
a developer capable of activating the color former when in contact therewith;
wherein the microcapsules are configured to remain intact during application upon a first surface to be coated, and to rupture upon impact between the first surface and another surface thereby releasing the color former to contact the developer and provide a visual indication of location of the impact.
2 . An impact indicator composition according to claim 1 wherein the microcapsules have a diameter of about 2-8 microns.
3 . An impact indicator composition according to claim 1 wherein the microcapsules have a wall thickness of about 110-120 nanometers.
4 . An impact indicator composition according to claim 1 wherein the developer is in the form of particles.
5 . An impact indicator composition according to claim 1 wherein the composition further comprises about 40-60% pigment.
6 . An impact indicator composition according to claim 1 wherein the composition further comprises about 5-20% binder.
7 . An impact indicator composition according to claim 1 wherein the developer comprises a phenolic resin.
8 . An impact indicator composition according to claim 1 wherein the core comprises the at least one color former dissolved in a carrier oil.
9 . An impact indicator composition according to claim 1 wherein the color former is a leuco dye.
10 . An impact indicator composition according to claim 1 wherein the composition is an aqueous liquid comprising about 5 to 35% by weight microcapsules, wherein the core comprises at least one color former dissolved in a carrier oil; about 5 to 30% by weight developer particles; and about 3 to 30% binder; wherein the isocyanate comprises a bis-isocyanate and the polyamine comprises guanidine.
11 . A device for precisely indicating an impact location, comprising:
a container; and
a liquid impact indicator composition within the container;
wherein the impact indicator composition comprises:
microcapsules having a cross-linked polyurea shell and a core surrounded by the shell, wherein the core comprises at least one color former in a carrier oil; and
a developer capable of activating the color former when in contact therewith.
12 . A device according to claim 11 , further comprising a pump or aerosol spray nozzle configured to spray the composition.
13 . A device according to claim 12 , wherein the impact indicator composition further comprises a foam control agent.
14 . A device according to claim 11 , wherein the developer comprises phenolic resin particles.
15 . A device according to claim 11 wherein the core comprises the at least one color former dissolved in a carrier oil and the color former is a leuco dye.
16 . A device according to claim 11 , wherein the microcapsules have a diameter of about 2-8 microns and a wall thickness of about 110-120 nanometers.
17 . A method of indicating a contact location, comprising:
applying an impact indicator composition to at least a portion of a first surface;
wherein the impact indicator composition comprises microcapsules having a cross-linked polyurea shell and a core surrounded by the shell, wherein the core comprises at least one color former dissolved in a carrier oil; and
developer particles capable of activating the color former when in contact therewith.
18 . A method of indicating a contact location according to claim 17 where the applying is by spraying a coating of the composition on at least a portion of the first surface.
19 . A method of indicating a contact location according to claim 17 comprising activating the impact indicator composition by causing or permitting an impact from a second surface on the first surface causing a visual color change to appear on the first surface.
20 . A method according to claim 17 further comprising indicating a relative force of impact wherein the composition comprises a plurality of microcapsules carrying different color formers and being capable of rupturing at pre-determined impact forces.