Indicator devices and articles comprising the indicator device

Abstract

An indicator device comprising a first carrier material; a first pigment disposed in the first carrier material, the first pigment capable of being degraded by exposure to UV radiation; and wherein the first carrier material is configured so as to have a varying thickness such that upon exposure to UV radiation, a visible change in the pigment will occur which will result in a varying visible change over a first surface of the first carrier material.

1 . An indicator device comprising: 
 a first carrier material;    a first pigment disposed in the first carrier material, the first pigment capable of being degraded by exposure to UV radiation; and    wherein the first carrier material is configured so as to have a varying thickness such that upon exposure to UV radiation, a visible change in the pigment will occur which will result in a varying visible change over a first surface of the first carrier material.    
     
     
         2 . The indicator device of  claim 1 , wherein the visible change comprises a color change.  
     
     
         3 . The indicator device of  claim 1 , wherein the varying visible change comprises a stepwise visible change.  
     
     
         4 . The indicator device of  claim 1 , further comprising a marking concealed by the first pigment, the marking capable of being visible upon degradation of the first pigment.  
     
     
         5 . The indicator device of  claim 1 , further comprising a second pigment disposed in the first carrier material, the second pigment capable of being degraded by exposure to UV radiation and having a different fastness to light than the first pigment.  
     
     
         6 . The indicator device of  claim 1 , further comprising a second carrier material disposed in contact with the first carrier material; and a second pigment disposed in the second carrier material, the second pigment capable of being degraded by exposure to UV radiation.  
     
     
         7 . The indicator device of  claim 1 , wherein the indicator device further comprises an adhesive disposed on a second surface of the first carrier material opposite the first surface of the first carrier material.  
     
     
         8 . The indicator device of  claim 1 , wherein the first carrier material comprises polyethylene; and the first pigment comprises C.I. Pigment red 48:30.  
     
     
         9 . The indicator device of  claim 1 , wherein the indicator device comprises a formulation comprising greater than or equal to about 90 wt. % of the first carrier material and 0.5 wt. % to about 10 wt. % of the first pigment, wherein weight percents are based on a total weight of the formulation.  
     
     
         10 . The indicator device of  claim 9 , wherein the first pigment is present in an amount of about 1 wt. % to about 3 wt. %.  
     
     
         11 . The indicator device of  claim 9 , wherein the first carrier material comprises polyethylene; the first pigment comprises C.I. Pigment red 48:30, and the formulation further comprises about 0.2 wt. % to about 0.5 wt. % of a UV stabilizer.  
     
     
         12 . The indicator device of  claim 1 , wherein degradation of the first pigment corresponds to degradation of an article, such that the indicator device is capable of providing a visual indication of a remaining life of the article.  
     
     
         13 . The indicator device of  claim 1 , wherein degradation of the first pigment corresponds to a predetermined maximum permitted UV exposure for an article such that the indicator device is capable of providing a visual indication that the article has received the predetermined maximum permitted UV exposure.  
     
     
         14 . The indicator device of  claim 1 , wherein the indicator device is fixedly disposed on or integrated into an article such that degradation of the pigment corresponds to degradation of the article, such that the indicator device is capable of providing a visual indication of a remaining life of the article.  
     
     
         15 . The indicator device of  claim 1 , wherein degradation of the pigment corresponds to a time interval that is predetermined by legislation or other regulations.  
     
     
         16 . An indicator device comprising: 
 a first carrier material;    a first pigment disposed in the first carrier material, the first pigment capable of being degraded by exposure to UV radiation;    a second carrier material disposed in contact with the first carrier material; and    a second pigment disposed in the second carrier material, the second pigment capable of being degraded by exposure to UV radiation, wherein the second pigment has a different fastness to light than the first pigment such that a visible change in indicator device occurs from the first carrier material to the second carrier material.    
     
     
         17 . The indicator device of  claim 16 , wherein the visible change comprises a color change.  
     
     
         18 . The indicator device of  claim 16 , wherein the visible change comprises a stepwise visible change.  
     
     
         19 . An indicator device comprising: 
 a carrier material;    a first pigment disposed in the carrier material, the first pigment capable of being degraded by exposure to UV radiation; and    a marking concealed by the first pigment, the marking capable of being visible upon degradation of the first pigment.    
     
     
         20 . The indicator device of  claim 19 , further comprising a second pigment disposed in the carrier material, the second pigment capable of being degraded by exposure to UV radiation, wherein the second pigment has a different fastness to light than the first pigment.  
     
     
         21 . An article comprising: 
 a surface;    an indicator device disposed in physical communication with the surface, the indicator device comprising    a first carrier material;    a first pigment disposed in the first carrier material, the first pigment capable of being degraded by exposure to UV radiation; and    wherein the first carrier material is configured so as to have a varying thickness such that upon exposure to UV radiation, a visible change in the pigment will occur which will result in a varying visible change over a first surface of the first carrier material.    
     
     
         22 . The article of  claim 21 , wherein the visible change comprises a color change.  
     
     
         23 . The article of  claim 21 , wherein the varying visible change comprises a stepwise visible change.  
     
     
         24 . The article of  claim 21 , wherein degradation of the first pigment corresponds to degradation of the article, such that the indicator device is capable of providing a visual indication of a remaining life of the article.  
     
     
         25 . The article of  claim 21 , wherein the article is a helmet.