Laser engraving methods and compositions, and articles having laser engraving thereon

Abstract

The invention provides a composition having laser engraving properties, comprising a host material and an effective amount of a laser enhancing additive. The laser enhancing additive comprises a first quantity of least one of copper potassium iodide (CuKI 3 ) or Copper Iodide (CuI), and a second quantity at least one substance selected from the group consisting of zinc sulfide (ZnS), barium sulfide (BaS), alkyl sulfonate, and thioester. The composition can be engraved with grayscale images by an Nd:Yag laser and can be added to laminates or coatings. The composition can be used during the manufacture of many articles of manufacture, including identification documents.

1 . A composition having laser engraving properties, comprising: 
 a host material; and    an effective amount of a laser enhancing additive, the laser enhancing additive comprising: 
 a first quantity of at least one of copper potassium iodide (CuKI 3 ) or Copper Iodide (CuI); and  
 a second quantity of at least one substance selected from the group consisting of zinc sulfide (ZnS), barium sulfide (BaS), alkyl sulfonate, and thioester.  
   
     
     
         2 . The composition as recited in  claim 1 , wherein the laser enhancing additive is present in an amount from about 0.001 to 100 percent by weight based on the total weight of the composition.  
     
     
         3 . The composition as recited in  claim 1 , wherein host material is substantially transparent and the laser enhancing additive is present in an amount from about 0.001 to 0.1 percent by weight based on the total weight of the composition.  
     
     
         4 . The composition as recited in  claim 1 , wherein the laser enhancing additive is present in an amount that is about 0.06 percent by weight based on the total weight of the composition.  
     
     
         5 . The composition as recited in  claim 1 , wherein the composition comprises a coating.  
     
     
         6 . The composition as recited in  claim 1 , wherein the composition comprises a laminate.  
     
     
         7 . The composition as recited  claim 1 , wherein the composition is laser engraveable to form a grayscale image.  
     
     
         8 . An article of manufacture capable of being laser engraved with a grayscale image, comprising: 
 a core layer having a first surface;    a first layer comprising a first host material, the first host material comprising an effective amount of a first laser enhancing additive comprising at least one of one of copper potassium iodide (CuKI 3 ) or Copper Iodide (CuI); and    a second layer comprising a second host material, the second layer oriented in relation to the first host material such that a single laser beam can penetrate both at least a portion of the first layer and at least a portion of the second layer, the second host material comprising an effective amount of a second laser enhancing additive, the second laser enhancing additive selected from the group consisting of zinc sulfide (ZnS), barium sulfide (BaS), alkyl sulfonate, and thioester;    wherein the first and second layers are operably coupled to each other and at least one of the first and second layers is operably coupled to the first surface of the core layer.    
     
     
         9 . The article of manufacture as recited in  claim 9 , further comprising a grayscale image laser engraved into at least one of the first and second layers.  
     
     
         10 . The article of manufacture as recited in  claim 8 , wherein the article of manufacture is an identification document.  
     
     
         11 . A method of engraving a material by exposing the material to laser radiation, comprising: 
 adding to the material an effective amount of a laser enhancing additive, the laser enhancing additive comprising: 
 at least one of copper potassium iodide (CuKI 3 ) or Copper Iodide (CuI); and  
 at least one substance selected from the group consisting of zinc sulfide (ZnS), barium sulfide (BaS), alkyl sulfonate, and thioester; and  
   exposing the material to laser radiation in a manner that causes the material to be engraved by the laser radiation.    
     
     
         12 . The method recited in  claim 12 , wherein the effective amount of the laser enhancing additive comprises 0.001% to 100% by weight of the material.  
     
     
         13 . The method recited in  claim 12 , further comprising laser engraving an indicium in grayscale in at least a portion of the material.  
     
     
         14 . The method recited in  claim 12 , further comprising using the laser engraved material in the manufacture of an identification document.  
     
     
         15 . An identification document, comprising: 
 a core layer;    a first layer overlaying at least a portion of the core layer and affixed to the portion of the core layer, the first layer comprising an additive that comprises: 
 an effective amount of least one of copper potassium iodide (CuKI 3 ) or Copper Iodide (CuI); and  
 an effective amount of at least one substance selected from the group consisting of zinc sulfide (ZnS), barium sulfide (BaS), alkyl sulfonate, and thioester.  
   
     
     
         16 . The identification document of  claim 15 , wherein the first layer is at least one of a coating and a laminate.  
     
     
         17 . The identification document recited in  claim 15 , wherein the identification document bears a first indicium thereon, the indicium obtained by directing a laser beam through at least a portion of the first layer.  
     
     
         18 . The identification document recited in  claim 17 , wherein the indicium comprises at least one of a gray scale image, photograph, text, tactile text, graphics, information, security pattern, security indicia, and digital watermark.  
     
     
         19 . The identification document recited in  claim 17  wherein the first indicia comprises variable information.  
     
     
         20 . The identification document recited in  15  above, wherein the first layer further comprises: 
 a first sub layer comprising an effective amount of least one of copper potassium iodide (CuKI 3 ) or Copper Iodide (CuI); and  
 a second sub layer comprising an effective amount of at least one substance selected from the group consisting of zinc sulfide (ZnS), barium sulfide (BaS), alkyl sulfonate, and thioester.