TRANSLUCENT CARD
Technical Field
The present invention is directed to an improved transparent or translucent card, such as a credit card, or the like, and method of making same. The card is transparent or translucent to human viewing yet can be detected by infrared light.
Credit cards, as well as other cards such as shopping cards, pre-paid cards, retail store cards, financial cards, insurance cards, traveling cards, transit passes, tickets, personal identification cards, are finding increasingly widespread use. So, efforts have been made to provide these cards with attractive, distinctive appearances to identify, promote or distinguish the company or association, which is issuing or supporting the card. Cards having a transparent portion can be found, combined with printed graphics and stamped holograms that are useful for validating cards and supporting their authenticity. For example, Citibank, at one time, issued a "Citibank Magic Middle Card", which had a transparent zone in the middle of the card. Chase Manhattan Bank offered a card with a transparent magnifier in the middle of the card. Further, U.S. Patent No.
5,608,203 to Finkelstein et al. and U.S. Design Patent No. Des. 358,419 teach credit cards with magnifying lenses.
One problem associated with transparent credit cards is effectively securing the layers of the credit card so they will remain bonded without encountering problems in breakage. Further, the card must be transparent and yet readable by the infrared (IR) scanning equipment used to note the presence of credit cards. Typically, the light sources in an automatic teller machine or ATM are laser diodes, and so the source and detector operate in the range of 720 to 1200 nanometers (run) wave-length, which is near infrared wave-length. Upon bringing the appropriate layers together to form a card structure, that structure needs to meet the standards for identification cards or credit cards, such as International Standard ISO 7810-1985. As such, it needs to resist delaminating and curling, have enough flexibility to handle the stress of being handled and flexed in wallets, while functioning for a variety of card purposes, including as a credit card. U.S. Patent Nos. 6,290,137 and 6,296, 188 to John H. Kiekhaefer disclose a transparent or translucent financial transaction card which is detectable to automated card processing equipment by screen-printing an IR blocking filter coating on the surface of
the PVC core stock. Kiekhaefer suggests that the light filtering material could be incorporated into the "material sheet" prior to or during extrusion or calendaring or is sublimated in by heat diffusion processing, but neither patent contains any examples for the concept nor any materials to use or details on how to achieve it. The patents issued based upon claims to covering (preferably screen-printing) the material sheet with a filter, i.e., an IR filter. One of the difficulties with manufacturing the transparent cards using screen printing techniques is imperfections from the printing step can occur due to the printing step itself or due to errors in the ink composition which prevent proper flow and result in the imperfections. Further transparent or partially transparent credit cards are taught in several design patents, including U.S. Patent Nos. Des 438,563; Des. 442,627; and Des. 406,861.
IR compositions are known for incorporation into polymeric films that are used for agricultural films or optical laminates. For example, U.S. Patent No. 5,518,810 to Nishihara et al and No.6,261,684 to Takahashi et al. teach the use of tin-doped indium oxide or ITO powders in various polymers, including polyvinyl chloride polymers. U.S. Patent No. 6,136,904 to Amano et al. teaches the use of diimmonium type IR absorbers in polycarbonate resins. U.S. Patent No. 4,590,118 to Yatabe et al and No. 3,850,502 to Bloom et al teach the use of metal complex compounds in polymeric layers to produce optical laminates. U.S. Patent No. 5,705,101 to Oi et al teaches the use of phthalocyanine which can be coated on to films or kneaded into adhesives for application to films which are used as optical recording medium or window materials. U.S. Patent Nos. 6,248,817 5,767,179 to K. Takado teach the use of metal (lithium-aluminum) hydroxide complex salts in agricultural films.
Background Art The present invention is to a card, such as a credit card, which is transparent to the human eye or has a translucent appearance, and a method of making a card. The card structure is essentially a polyvinyl chloride core, in the form of a card, having first and second faces and incorporating an IR absorber or blocker. On the first face, which might be considered the front of the card, is the printing or graphics on it and a clear overlay layer. Magnetic information containing strips, as well as signature strips, and the like, can be adhered to the second face of the card over the clear overlay layer.
For the purposes of this application, the term "superclear" or "superclear PVC" is
intended to mean a layer of polyvinyl chloride having the highest clarity. While this is, unfortunately, a subjective quality, it is usually measured visually against the clarity of a high standard, such as, e.g., water. The "clear overlay" is not intended to be less clear than the "superclear" layer and can be the same, although not the same dimensionally. The "clear overlay" functions to protect the printed layer and its clarity will vary depending upon the needs of the card. Thus, the "clear overlay" can range in clarity from "superclear" to simply "clear".
The card structure is made by laminating together the layers that comprise the card structure, or could be made by the lamination of two or more layers together to form a substructure and subsequently joining the additional layers. For example, if the card structure is made of five individual layers, the card can be made by assembling and laminating the layers together or by making a first laminate which includes the PVC layer which contains the IR blocker and subsequently joining the subassembly to additional layers or laminates comprised preferably of PVC, although other polymeric materials could be employed. Printing and the further identification components are added at appropriate steps in the manufacturing process to tailor the card so that it will serve a specific function, such as a credit card, a shopping card, a pre-paid card, an identification card, or the like. In addition, other polymeric or PVC layers can be joined to the laminate as necessary.
The core is preferably made using a single PVC core, which contains the IR blocker, but it could be made using two or more layers of PVC, containing an IR blocker, where each layer is about one-half, or a fraction, of the desired thickness of the core structure, and the two or more layers are subsequently joined together. Of course, manufacturing the core using more than two layers of PVC, normally, is less desirable because the additional steps would add to the manufacturing cost. For example, the use of two core layers allows the additional layers and/or printing used to make the card to be joined to a respective half of the core and then each half of the core is joined to make the whole card.
As was noted earlier, the card structure can be made by laminating the core layer and two superclear outer layers together to form a substructure and subsequently joining additional layers to the core structure. Using a three-part PVC core and selecting one of the two outer surfaces or faces of the PVC core structure, printing or graphics will be applied, and subsequently a clear overlay layer is adhered to the first face of the PVC core
structure. This face can be considered the front of the card. To the second face of the PVC core element or substructure, further graphics or printing can be placed, and another clear overlay layer is bonded to the second face of the PVC core element. Preferably, the laminate is made by assembling the layers and then joining them under heat and/or pressure so that they are bonded across the entire face of the card. But, when there is a lot of printing and graphics are employed, it may be desirable to use an adhesive to bond the overlayer(s). The adhesive is a PVC-based adhesive.
Printing and the further identification components are added at appropriate steps in the manufacturing process so that the card can be tailored to serve its desired specific function, such as a credit card, a shopping card, a pre-paid card, an identification card, or the like. Magnetic information containing panels or pads, as well as signature strips and the like, can be adhered to the second face of the clear overlay that covers the core element. Also, chips, which require contact or are contactless, can be placed upon either or both clear overlay layers, if desired.
The core elements are made by mixing the infrared or IR blocking agent(s), which are also referred to as IR filter(s) or IR blocking dyes, and the PVC polymer composition and calendaring the composition to form the core stock. The amount of IR blocking agent will be an amount that is effective to enable an ATM to read the presence of a card when it is in use, as is typically done as part of the operation of the card reader that is part of an ATM. The DR. blocking agent and PVC polymer can be mixed or blended by extrusion, banbury mixing, or the like mixer used for blending additives and polymers such as PVC. The amount of IR blocker will be in an amount of between about 0.05 % by weight of the polymer and 10% by weight, with O.05% to 5.0% and 0.1% to 3.0% being preferred ranges. The precise amount will depend upon the blocker or blockers employed and the color desired for the card. If the amount is too much, it will reduce the clarity of the card as well as increase the costs due to excessive use of materials. The IR blocker or blockers employed will be reflective of near infrared light in the range of 720 to 1100 nanometers.
After blending the mixture is calendared or extruded into sheet form, and cut to printable and laminatable sheet size. Although a single IR blocker can be used, it is preferred to employ a blend of IR blockers. Although not critical, depending upon the processing chosen, the IR blocker(s), may be such that will not be affected by the heat of processing. So, some blockers are more stable at higher temperatures and thus acceptable for the processing conditions. The IR blocking agents can be light absorbing, light
scattering, light detracting, light deflecting, or light blocking compositions. The IR blocking agents can be any color, including clear, blue, red, smoke, green, yellow, or any other color. A preferred core stock, in which the IR blocking agents and the PVC are already blended and calendared, is available from Empire Plastics, Newcomerstown, Ohio, as IR-TruBlock. The core stock incorporates a blend of IP blocking agents that provides heat resistance up to 165°C, preferably in the range of 120°C to 165°C, with
120°C to 140°C being also preferred, and adsorption of near infrared light in the range of 720 to 1100 nanometers. Alternatively one or more of the many IR blocking compounds know for incorporation in PVC compositions can be employed, such as the infrared absorption dye powders sold under the names Epolight HI-57 from Epolin, Inc., Newark, NJ; ADS 1120P, ADS 870MC, and ADS 1065A sold by American Dye Source, Quebec, Canada; and 3D Blue Dye sold by Coburn Corp. The finished PVC core stock will have to be able to block IR light transmittance in the range of 720 to 1100 nanometers.
The core structure is made by laminating, using heat and pressure, a PVC core stock or film, which contains an infra red absorber and has a thickness of about 0.00175 to 0.025 inch, preferably a thickness of about 0.0075 to 0.0135 inch, with 9.75 mils being preferred, to two superclear PVC films, each of which has a thickness of about 0.0050 to 0.0125 inch, preferably a thickness of about 0.0075 to 0.0090 inch, with about 8.5 mils thick being preferred. The superclear PVC films are laminated to each of the two faces of the PVC core stock so that there is one on each side. The laminating could be achieved using a hydraulic laminating press. The temperatures and pressures are not critical, and will be in the range of 250°F to 300°F, with 275°F being preferred, and a pressure of 175 to 250 psi, with 200 psi being preferred.
Any printing to fonn the desired graphics, e.g., letters, number, pictures, shapes, patterns, etc., to provide the desired aesthetics is applied to first side of the core composite on the superclear layer on the PVC core stock. After the printing, a clear PVC overlay film is applied to protect the printed surface. The printing can be done by any typical printing technique, although heat set and cold set web offset printing conventional inks will work. Other types of printing that can be employed including printing by silk-screen printing, digital printing, gravure printing, rotary printing, and the like using with an ultraviolet curable ink which is cured immediately after being applied to the layer by directing ultraviolet light on the ink. Finally, the print layer is coated with a clear PVC overlay to protect the print surface. If graphics or printing is desired on the second face of
the card, it will be done after the first face is printed and the clear PVC overlay is laminated to that face. A second clear PVC overlay is laminated to the surface of the second superclear PVC film. Each of the clear overlay layers has a thickness of about .0005 inch to about .005 inch, preferably a thickness of about .001 inch to about .004 inch, with about 2.0 mils being preferred. If any further graphics are desired they can be applied to the clear PVC core structure by an appropriate printing technique before the clear PVC overlay is applied. The clear overlay laminates preferably are joined to the core structure by application of heat and/or pressure alone, but they could be joined by applying a PVC adhesive to the exposed superclear layer of the PVC core structure and joining the overlay laminate or, alternatively, the PVC adhesive could be precoated on the overlay layer. Each of the laminates could be made by continuous process where the process involves feeding continuous sheets of the materials or they could be made by forming sheets from which a fixed number of cards could be made. The plastic substrate is preferably in the fonn of a large sheet containing a plurality of credit cards. For example, the sheet could be of a size that would accommodate eight cards by eight cards, seven cards by eight cards, eight by nine, eight by ten, or twelve cards by six cards. Once the first and second laminates are joined, the cards can be die cut from the laminate sheets.
Identifying information means can be attached to each card. The identifying information means could be a magnetic tape which is attached to the card on a surface of the plastic substrate opposite the front surface of the substrate by a known hot stamping process, a roll or heat transfer process or a laminating process, or it could be a signature tape, a hologram, a photographic identification or the like.
The foregoing embodiments of the present invention have been presented for the purposes of illustration and description. These descriptions and embodiments are not intended to be exhaustive or to limit the invention to the precise fonn disclosed, and obviously many modifications and variations are possible in light of the above disclosure. The embodiments were chosen and described in order to best explain the principle of the invention and its practical applications to thereby enable others skilled in the art to best utilize the invention in its various embodiments and with various modifications as are suited to the particular use contemplated. It is intended that the invention be defined by the following claims.
Disclosure of the Invention
The present invention is the result of the discovery that transparent or translucent card structure, such as a credit, debit, or ATM card, a shopping card, a pre-paid card, an identification card, or the like, can be achieved using a polyvinyl chloride ("PVC") layers having an infra red (IR) blocker incorporated in it. The PVC layers are joined with additional polyvinyl chloride layers to form a card structure that will meet the standards for identification cards, such as International Standard ISO 7810-1985, and resist delamination and curling, and yet have enough flexibility to function for a variety of card purposes, including as a credit card. The cards can be overprinted, embossed, or provided with further identifying information components such as holograms, signature panels or pads, magnetic strips, photographic identification strips, contact chips, contactless chips, or a card company identifier.
For the purpose of this application, the term "credit card" is intended to include credit cards, as well as debit cards, ATM cards, shopping cards, pre-paid cards, security cards, identification cards, telephone cards, transit passes, traveling cards, personal identification cards, and the like, including cards having functional means such as holograms, signature panels or pads, magnetic strips, photographic identification strips, contact chips, contactless chips, card company identifier(s), and the like for identification, validation, and authentication.