Patent Application
20100028619
The present invention relates to tearable security laminates. More specifically, the present invention relates to a security card, comprising: a plastic card having edges; and a tearable security laminate attached to the plastic card by an adhesive layer, where the security laminate is tearable along an edge of the plastic card. In addition, the invention relates to methods of making security cards with security laminates.
A number of security features have been developed to help authenticate a document of value, thus assisting in preventing counterfeiters from altering, duplicating or simulating a document of value. Some of these security features may include overt security features or covert security features. Overt security features are features that are easily viewable to the unaided eye, such features may include holograms and other diffractive optically variable images, embossed images, and color-shifting films. In contrast, covert security features include images only visible under certain conditions, such as inspection under light of a certain wavelength, polarized light, or retroreflected light. One example of a security laminate that includes both overt and covert security features is 3M™ Confirm™ Security Laminate, which is commercially available from 3M Company based in St. Paul, Minn. This security laminate may be used with documents of value, such as identification cards, badges and driver licenses, and assists in providing identification, authentication and to help protect against counterfeiting, alteration, duplication, and simulation. Other examples of security laminates that include both overt and covert security features are illustrated in U.S. Pat. Publication No. 2003/0170425 A1 “Security Laminate,” (Mann et al.), and U.S. Pat. Publication No. 2006/0029753-A1, “Tamper-Indicating Printable Sheet for Securing Documents of Value and Methods of Making the Same,” (Kuo et al.) Examples of some other security-related devices or films are taught in U.S. Pat. Nos. 3,801,183, 4,688,894, and 6,288,842.
Embodiments of the invention are generally directed at tearable security laminates and in particular, security cards with tearable security laminates attached to them. In one embodiment, the invention is directed to a security card comprising: a plastic card having edges; and a tearable security laminate comprising: a retroreflective layer comprising a plurality of microbeads partially embedded in a beadbond layer; a reflector layer between at least one of the microbeads and the beadbond layer; and an adhesive layer attached to the beadbond layer; where the security laminate is attached to the plastic card by the adhesive layer, and where the security laminate is tearable along an edge of the plastic card to form a tear in the security laminate that aligns with the edge of the plastic card.
In another embodiment, the invention is directed to a method of making a security card with a security laminate, the method comprising the steps of: providing a plastic card having edges; providing a tearable security laminate comprising: a retroreflective layer comprising a plurality of microbeads partially embedded in a beadbond layer; a reflector layer between at least one of the microbeads and the beadbond layer; and an adhesive layer attached to the beadbond layer; where the security laminate is larger than the plastic card; adhering the security laminate to the plastic card by the adhesive layer; and tearing the security laminate along an edge of the plastic card to form a tear in the security laminate that aligns with the edge of the plastic card.
In another embodiment, the invention is directed to a security card comprising: a plastic card having edges; and a tearable security laminate comprising: a retroreflective layer comprising a plurality of microbeads partially embedded in a beadbond layer, where the beadbond layer comprises polyurethane; a reflector layer between at least one of the microbeads and the beadbond layer; and an adhesive layer attached to the beadbond layer; where the security laminate is attached to the plastic card by the adhesive layer, where the adhesive layer comprises a polyester-based, hot-melt adhesive, and where the security laminate is tearable along an edge of the plastic card to form a tear in the security laminate that aligns with the edge of the plastic card.
As used herein, the term “normal lighting conditions” refers to the presence of ambient light that is substantially diffused, as with light typically used to light a room. The term “retroreflected light conditions” refers to ambient light that is substantially collimated, such as light cast by the headlight of an automobile or by a flashlight, and returns to the light source or the immediate vicinity thereof. The term “unaided eye” means normal (or corrected to normal) human vision not enhanced by, for example, magnification.
The present invention will be further explained with reference to the appended Figures, wherein like structure is referred to by like numerals throughout the several views, and wherein:
a is an enlarged view of a portion of the digitally recorded micrograph of the security laminate and card illustrated in
Security laminates are often used to protect documents of value, such as identification cards, badges and driver licenses. Security laminates may also assist in providing identification, authentication, or to help protect against counterfeiting, alteration, duplication, and simulation. When prior art security laminates are applied to identification cards, badges, driver licenses or other types of cards, they are typically die cut to size and then laminated to the cards. For example, for a typical printed card body measuring 2.12 inches wide by 3.37 inches in length, a security laminate will be die cut to approximately 2 inches wide by 3.2 inches in length, and then laminated to the card by use of a hot roll laminator. However, this configuration leaves the peripheral area on the card body unprotected from weathering or tampering, and it is not preferable from a cosmetic point of view. It is possible to achieve edge to edge coverage with the use of prior art security laminates on cards, however it often becomes necessary to cut the security laminate before lamination to exactly match the dimensions of the card. For example, in this case, cutting the security laminated to precisely measure 2.12 inches wide by 3.37 inches in length to match the dimensions of the card. However, it is often difficult to have the edges of the cut security laminate exactly register or align with the edges of the card. In addition, such equipment is often expensive or difficult to use. Alternatively, other prior art security laminates may be used to achieve edge to edge coverage of the security laminate on the card by applying an oversized security laminate to the card and then to die cut the laminate around the card. However, it is often difficult to provide equipment for achieving such means and the equipment may actually end up cutting off portions of the card, if the alignment between the card and equipment is not exact.
Therefore, there exists a need to provide a security laminate that is capable of adhering to a card and is tearable along the edge of the card to provide a security laminate that can protect and cover the entire surface of the card (sometimes referred to as “edge to edge coverage”) and not leave peripheral areas of the card body unprotected. In addition, there is also a need for a security laminate that may be easily torn along the edge of the card by hand to form a “clean” tear. The term “clean tear”, as used herein, refers to the tear in the security laminate as conforming with or aligning with the edge of the card after the security laminate 10 has been torn against the edge 30 of the card 22, regardless of the shape or edges of the card. That is, when a person runs his finger along the edge of the card, the edge of the security laminate is adjacent or aligns with the edge of the card and it is smooth to the touch, in comparison to prior art security laminates that are torn by hand that leave jagged edges or security laminates that may lift off of the card surface after they are torn by hand.
One embodiment of the tearable security laminate 10 of the present invention on a card is illustrated in
The reflector layer 20 is preferably a transparent, high refractive index material. Examples of useful reflector layer materials include bismuth trioxide, zinc sulfide, titanium dioxide, zirconium oxide, and a stack of zinc sulfide/Na3AlF6. One example of a suitable reflector layer 20 is a transparent, high refractive index material that is described in U.S. Pat. No. 3,801,183, which is hereby incorporated by reference.
One example of a suitable beadbond layer 14 is the inkjet receptive beadbond layer described in U.S. Pat. Publication No. 2006/0029753-A1, which is hereby incorporated by reference. This inkjet receptive beadbond layer 14 is used to accept images or other information in a discernable or readable form, typically by printing onto the exposed bead side of security laminate 10, with the majority of the printed ink retained in the inkjet receptive layer 14. The ink in the inkjet receptive beadbond layer 14 forms an image and other information, such as a picture or personalized information in the case of a passport or driver's license, illustrated in
In one preferred embodiment, the beadbond layer 14 includes polyurethane. In another preferred embodiment, the elongation at break of the beadbond layer is less than about 500%. In another preferred embodiment, the elongation at break of the beadbond layer is less than about 200%. Another example of a suitable beadbond layer 14 is disclosed in U.S. Pat. No. 4,530,859, which is hereby incorporated by reference. Other examples of suitable materials for the beadbond layer 14 is a polyurethane sold under the Bayhydrol brand available from Bayer Corporation in Pittsburg, Pa. These embodiments of the beadbond material for the beadbond layer 14 are especially useful for creating security laminates 10 that can be torn along the edge of the substrate or plastic card 22, because they are not as elastic and have a tendency to break more easily than other beadbond materials.
In one embodiment of the security laminate of the present invention, the security laminate 10 may include an overt indicia 24 that is preferably visible through the security laminate 10 when viewed under normal lighting conditions. In this embodiment, the retroreflective layer 18 is substantially transparent with overt indicia 24 being visible when illuminated under normal lighting conditions. The overt indicia 24 may include a printed image of a human face, signature, fingerprint, alphanumeric information, a barcode, or any combination thereof. The overt indicia 24 may be attached or printed directly to the beadbond layer 14 opposite the microbeads 12. (not shown) Alternatively, the overt indicia 24 may be attached or printed directly on the substrate 22, which is then attached to the security laminate 10 by a layer of adhesive 16. In this embodiment, the adhesive 16 is preferably transparent to allow the viewer to see the overt indicia 24. Alternatively, the overt indicia 24 may be observed in reverse format on the rear side of the security laminate 10.
In another embodiment, the security laminate 10 may include a floating image as an overt indicia 24. One example of a suitable floating image taught in U.S. Pat. No. 6,288,842 which is hereby incorporated by reference.
In another embodiment, the security laminate 10 may include a covert indicia 26 that is preferably visible when the security laminate 10 is illuminated by, for example, retroreflected light. The covert indicia 26 is located between the reflector layer 20 and the glass microbeads 12. The covert indicia 26 may be included adjacent a portion of the microbeads 12 or adjacent all of the microbeads 12. The different covert indicia 26 under adjacent microbeads 12 may form a printed image of symbol, word, logo, or any combination thereof.
The security laminate 10 may include any combination and any number of overt indicia 24, 28 and covert indicia 26. For example, the security laminate 10 may include an overt indicia 24 in combination with a covert indicia 26. As another example, the security laminate 10 may include either an overt indicia 24 or a covert indicia 26. As yet another example, the tamper-indicating security laminate 10 may include an overt indicia 28 in combination with a covert indicia 26. The security laminate 10 may just include an overt indicia 28, or may include an overt indicia 24, a covert indicia 26 and an overt indicia 28.
The security laminate 10 is preferably bonded to a substrate 22 by the adhesive 16, as illustrated in
Useful adhesives 16 for bonding the security laminate 10 to the substrate 22 include heat activated adhesives, ultraviolet light curable adhesives, thermosetting adhesives and remoistenable adhesives. In another embodiment, additional layers of adhesive or substrates may be attached to the substrate 22. For example, a layer of pressure sensitive adhesive and liner may be added to create a self-adhesive label. In a preferred embodiment, the adhesive 16 is a polyester-based, hot-melt adhesive. In another preferred embodiment, the thickness of the adhesive layer is less than about 3 mils. These embodiments of the adhesive 16 are especially useful for creating security laminates 10 that can be torn along the edge of the substrate or plastic card 22, as they provide sufficient adhesion between the security laminate 10 and the plastic card 22.
The adhesive 16 is illustrated in
In
In contrast,
The tear strength of the security laminate 10 of the invention is reached before the bond strength of the adhesive 16 is surpassed to allow the security laminate to tear before lifting off from the card. In addition, the security laminate 10 of the invention allows tearing of the security laminate when attached to the card which aligns with the edge of the card.
a illustrates an enlarged view of a portion of the digitally recorded micrograph of the security laminate and card illustrated in
The operation of the present invention will be further described with regard to the following detailed examples. These examples are offered to further illustrate the various specific and preferred embodiments and techniques. It should be understood, however, that many variations and modifications may be made while remaining within the scope of the present invention.
An adhesive solution was prepared by dissolving a polyester resin (Vitel 2200B, available from Bostik Findley, Middleton, Mass., or Adcote 2140, available from Rhom and Haas, Philadelphia, Pa.) by 40 wt % in methyl ethyl ketone (MEK) and toluene. The solution was then coated onto a silicone release liner (2 SAB, available from Mitsubishi Polyester Film, Greer, S.C.) using a coating speed of 10 foot/min. The coating was dried in a 3-zone oven with temperature set at 140° F., 150° F. and 160° F. The wet gap was varied so that the thickness of the dried adhesive was approximately 0.5 mil (12.7 μm), 1 mil (25.4 μm), 2 mil (50.8 μm) and 3 mil (76.2 μm).
A sheet was prepared according to the procedure described in Example 1 of U.S. Pat. No. 3,801,183, utilizing the beadbond disclosed in U.S. Pat. No. 4,530,859 both of which are hereby incorporated by reference. The face side of the sheet was then laminated onto the aforesaid adhesive using a roller heated at 190-195° C. Upon cooling, the carrier and release liner were peeled off and a security laminate of a retro-reflective film layer with the adhesive on one side was obtained. The retro-reflective film had two layers; a layer of glass micro beads with diameter of about 40-100 μm partially embedded in a beadbond layer of polyurethane.
The security laminate was then bonded onto a Tuff II card (Plastag Company, Elk Grove Village, Ill.) using a P-640i Zebra Printer (Zebra Technologies Corporation, Vernon Hills, Ill.). The card was a composite made of alternating layers of polyvinylchloride (PVC) and polyethylene terephthalate (PET), with the exposed sides of the cards used being PVC. The card measured approximately 85.5 mm long, 54 mm wide and 0.762 mm thick. The temperature of the upper and lower heat rollers in the printer was set at 145° C. The roller speed was set at about 0.5 inch/sec. Because the security laminate produced above was larger than the card, an overlay was obtained after lamination, i.e. the security laminate extended beyond the outer card dimensions. The overlaying portion of the security laminate was then removed by hand tearing along the edges of the card. Visual examination indicated that the torn edges of the security laminate were clean and smooth, except for those samples with 3-mil (76.2-μm) thick adhesive where slight roughness was observed. An optical micrograph of the plan view of a typical clean edge was taken using an optical microscope (SZX12 made by Olympus Corporation, Tokyo, Japan) attached to a digital CCD camera (Spot Insight made by Diagnostic Instruments, Sterling Heights, Mich.). The micrograph of
A 1-mil (25.4-μm) thick adhesive was prepared as in Working Example 1. A 0.92-mil (23.4-μm) thick neat PET film (3M Company, St. Paul, Minn.) was then laminated onto the adhesive using a Model 5560 bench laminator (Thermal Laminating Corporation, Evanston, Ill.). The temperature of the front and rear heating zones of the laminator was set at 138° C. and 157° C., respectively. After removing the release liner, the security laminate was bonded onto a Tuff II card using the P-Model 5560 bench lamination as described in Working Example 1. Upon hand tearing of the excessive portion of the security laminate against the edges of the card, the security laminate showed apparent fractures, giving rise to a zigzag tear path illustrated in
A 2-mil thick ethylene-acrylic acid (EAA) adhesive was extruded using Primacor 3330 resin (Dow Chemicals, Midland, Mich.). A security laminate with a retroreflective film layer with the EAA adhesive on one side was prepared as in Working Example 1. After removing the release liner, the security laminate was bonded onto a Tuff II card using a Model 5560 bench laminator as described in Comparative Example 1. There was a very weak adhesion between the security laminate and the card. As a result, when hand tearing the overlaying portion of the security laminate against the edges of the card, part of the security laminate peeled off from the card surface, resulting in the tear path illustrated in
A piece of 3M Scotchlite 9720 laminate (3M Company, St. Paul, Minn.) was bonded onto a Tuff TI card using a Model 5560 bench laminator as described in Comparative Example 1. Scotchlite 9720 has a similar construction to the retroreflective security laminate prepared in Working Example 1. But, the key component used in the beadbond formulation in Scotchlite 9720 was Vitel 3550 (Bostik Findley, Middleton, Mass.). It has an elongation at breack of over 2000%. Therefore, Scotchlite 9720 is very stretchy. This property of Scotchlite 9720 made it very difficult to hand tear the excessive security laminate away from the card. This example appeared to suggest that to obtain clean or smooth tear edges it is important not to use an elastic material as the beadbond.
The tests and test results described above are intended solely to be illustrative, rather than predictive, and variations in the testing procedure can be expected to yield different results.
The present invention has now been described with reference to several embodiments thereof. The foregoing detailed description and examples have been given for clarity of understanding only. No unnecessary limitations are to be understood therefrom. All patents and patent applications cited herein are hereby incorporated by reference. It will be apparent to those skilled in the art that many changes can be made in the embodiments described without departing from the scope of the invention. Thus, the scope of the present invention should not be limited to the exact details and structures described herein, but rather by the structures described by the language of the claims, and the equivalents of those structures.
