WO2008060918A1

WO2008060918A1 - Card with color-shifting film

Info

Publication number: WO2008060918A1
Application number: PCT/US2007/083931
Authority: WO
Inventors: John H. Ko; Yuin Chang Oh; Kiam Seng Lau
Original assignee: 3M Innovative Properties Company
Priority date: 2006-11-15
Filing date: 2007-11-07
Publication date: 2008-05-22
Also published as: TW200900263A

Abstract

The present invention is directed to a card with a color-shifting film and a method of making same. The card comprises a substrate layer having a thermoplastic surface, a color-shifting film comprising a plurality of openings, and a top layer having first and second thermoplastic surfaces, wherein the color-shifting film is laminated between the thermoplastic surface of the substrate layer and the first thermoplastic surface of the top layer at elevated temperature and pressure.

Description

CARD WITH COLOR-SHIFTING FILM

Field of Invention

The present invention relates to a card with a color-shifting film and a method of making same.

Background

Cards, having personalization data such as photographs, signatures, fingerprints, personal alphanumeric information, barcodes, or the like, are commonly used to prove identity, to verify age, to access a secure area, to evidence driving privileges, to cash a check, and more. To prevent forgery of personalization data and subsequent use of forged cards, security features, preferably capable of showing evidence of tampering, are often added to cards for authentication.

One example of an overt security feature is a color-shifting film. A color-shifting film has several hundred thin layers of biaxially stretched polymers, and exhibits one color when viewed straight-on and then shifts to another color when viewed at a large angle. When a color-shifting film is laminated into a card, the bonding between the film and the card body is often quite weak. As a result, counterfeiters may cut the card apart, remove the film from the card body and reuse the film in a forged card. Further, in a color-shifting film the adhesion between the skin layers and the optical core is often very low, so delamination may readily occur at the interfaces between the skin layers and the optical core. Thus even if a color-shifting film is coated with a primer or an adhesive before it is laminated into a card to increase the bonding between the film and the card body, counterfeiters may still cut the card apart, peel off the optical core from the skin layers and reuse the optical core in a forged card.

Summary

The present invention is directed to a card with a color-shifting film comprising a plurality of openings and a method of making same. The card of the present invention comprises a substrate layer having a thermoplastic surface, a color-shifting film comprising a plurality of openings, and a top layer having first and second thermoplastic surfaces, wherein the color-shifting film is laminated between the thermoplastic surface of the substrate layer and the first thermoplastic surface of the top layer at elevated temperature and pressure. A preferred material for the thermoplastic surface of the substrate layer is poly( vinyl chloride). In one embodiment, the substrate layer is a poly(vinyl chloride) core attached with a laminate of three alternating layers of poly( vinyl chloride) and poly(ethylene terephthalate). A preferred material for the first and second thermoplastic surfaces of the top layer is poly( vinyl chloride). In one embodiment, the top layer is a laminate of three alternating layers of poly( vinyl chloride) and poly(ethylene terephthalate). A preferred color- shifting film is clear-to-cyan color-shifting film. The method of making a card of the present invention comprises providing a substrate layer having a thermoplastic surface, providing a color-shifting film comprising a plurality of openings, providing a top layer having first and second thermoplastic surfaces, and laminating the color-shifting film between the thermoplastic surface of the substrate layer and the first thermoplastic surface of the top layer at elevated temperature and pressure.

Drawings

Fig. 1 illustrates a card of the present invention;

Fig. 2 is an exploded view of the structure of the card in Fig. 1 (for clarity, personalization data, scrambled indicia, security artwork, covert security features, and physical security elements are not shown);

Fig. 3 illustrates two more patterns of openings of the color-shifting film: A. slits of crosshatching ('x'); B. circular openings overlapped with slits of crosshatching ('x').

Detailed Description In one aspect, the present invention is directed to a card comprising a substrate layer having a thermoplastic surface, a color-shifting film comprising a plurality of openings, and a top layer having first and second thermoplastic surfaces, wherein the color-shifting film is laminated between the thermoplastic surface of the substrate layer and the first thermoplastic surface of the top layer at elevated temperature and pressure. Fig. 1 shows one embodiment of the invention. Card 10 has personalization data 12 such as photographs, signatures, fingerprints, personal alphanumeric information, barcodes, or the like that may be used for identification. Examples of card 10 include credit cards, debit cards, bank cards, passports, driver's licenses, employee badges, national ID cards, government ID cards, citizenship cards, permanent resident cards, voter registration cards, police ID cards, border crossing cards, security clearance badges and cards, and membership cards. Turning to Fig. 2, the substrate layer 20 of card 10 has a thermoplastic surface 22.

Thermoplastic refers to any pure or modified plastic that softens or melts when heated and then solidifies and regains its original properties upon cooling. Examples of suitable material for thermoplastic surface 22 include pure or modified polycarbonate, poly(ethylene terephthalate), poly(butylene terephthalate), polyethylene, polypropylene, poly( vinyl chloride), polyurethane, polyamide, polystyrene, acrylonitrile butadiene styrene, polyetherimide, polyacrylate, poly(vinyl acetate), polyacrylonitrile, polysulfone, poly(ether nitride), polycaprolactone, and combinations thereof. A preferred material for thermoplastic surface 22 is poly(vinyl chloride). In one embodiment, the substrate layer 20 is a poly( vinyl chloride) core attached with a laminate of three alternating layers of poly( vinyl chloride) and poly(ethylene terephthalate). For purposes of the present invention, the substrate layer 20 can be a multilayer structure.

The top layer 30 of card 10 has first and second thermoplastic surfaces 32, 34. Examples of suitable material for thermoplastic surfaces 32, 34 include pure or modified polycarbonate, poly(ethylene terephthalate), poly(butylene terephthalate), polyethylene, polypropylene, poly(vinyl chloride), polyurethane, polyamide, polystyrene, acrylonitrile butadiene styrene, polyetherimide, polyacrylate, poly(vinyl acetate), polyacrylonitrile, polysulfone, poly(ether nitride), polycaprolactone, and combinations thereof. A preferred material for thermoplastic surfaces 32, 34 is poly( vinyl chloride). In one embodiment, the top layer 30 is a laminate of three alternating layers of poly( vinyl chloride) and poly(ethylene terephthalate). For purposes of the present invention, the top layer 30 can also be a multilayer structure.

Preferably, thermoplastic surface 22 and/or thermoplastic surface 34 are capable of receiving images. Examples of suitable material for image-receiving, thermoplastic surfaces 22, 34 include pure or modified polyolefϊn, polycarbonate, poly(vinyl chloride), polyester, and combinations thereof. A preferred material for image-receiving, thermoplastic surfaces 22, 34 is poly( vinyl chloride) or plasticized poly(vinyl chloride). Color-shifting films 40 suitable for use in the present invention include any multilayer optical films that exhibit one color when viewed straight-on and then shift to another color when viewed at a large angle. A preferred color-shifting film 40 is clear-to-cyan color- shifting film (available from 3M Company, St. Paul, MN). This film 40 is substantially clear when viewed straight-on but becomes cyan when viewed at a large angle.

Preferably, indelible custom marks 44, such as logos, names, initials, or the like, are embossed onto the color-shifting film 40 where the marks 44 are red-gold when viewed straight-on and then shift to blue when viewed at a large angle. Color graphics 46 may also be used below the film 40 to create additional color shifts when viewed through the film 40. Further, covert security features 48, such as UV fluorescent ink, optical variable ink, or the like, may be added onto the film 40 to provide extra security.

The color-shifting film 40 used in the present invention comprises a plurality of openings 42. The openings can have any shape, such as circles, squares, triangles, letters, numbers, logos, slits, or the like, and can be arranged in any pattern, preferably in a regular pattern. Preferably, the openings comprise bi-directional slits, such as plus sign ('+'), crosshatching ('x'), caret ('^Λ'), greater-than sign ('>'), less-than sign ('<'), or the like. Fig. 3A depicts one type of bi-directional opening 42', a crosshatching. If other openings, such as circles or squares, are also used, the bi-directional slits may be overlapped or alternated with these additional openings. Fig. 3B shows circular openings overlapped with crosshatching slits 42". The openings can be made using mechanical methods, such as, for example, die cutting, but other suitable means, such as, for example, laser ablation or chemical etching, can also be used.

The color-shifting film 40 can have any shape, such as, for example, strip or patch, and can be arranged in any manner, such as, for example, from one edge of card 10 to another edge in either longitudinal or transverse direction. The film 40 can be coated with a primer or an adhesive to increase the bonding between the film 40 and thermoplastic surface 22 and/or the bonding between the film 40 and thermoplastic surface 32. When the film 40 is laminated between thermoplastic surface 22 and thermoplastic surface 32 at elevated temperature and pressure, thermoplastic surfaces 22, 32 are softened and fused together through the openings 42 of the film 40. This mechanically locks the film 40 between the thermoplastic surface 22 of the substrate layer 20 and the first thermoplastic surface 32 of the top layer 30. If the mechanical locks are sufficiently strong, when counterfeiters attempt to tamper with the film 40, at least one of the openings 42, 42', 42" causes the film 40 to show evidence of such tampering, which preferably prevents the film 40 from being reused. Evidence of tampering includes permanent stretching or damage to the film 40, such as, for example, tearing, breaking or delamination. Suitable lamination temperature and pressure can be selected based on the materials used as thermoplastic surfaces 22, 32. For example, to laminate two poly( vinyl chloride) surfaces, temperatures between about 140 ⁰C and about 150 ⁰C and pressures in the range of about 300 psi (-2.07 MPa) to about 350 psi (-2.41 MPa) may be used.

If thermoplastic surface 22 is capable of receiving images, security artwork 24, such as logos, microtext, guilloche, images or the like, may be printed using regular inks onto such surface 22 using printing technologies, such as, for example, dye diffusion thermal transfer printing, dye sublimation printing, laser printing, inkjet printing, and laser engraving/marking/etching, that are commonly used in card printing. Covert security features 26, such as UV fluorescent ink, optical variable ink, or the like, may also be printed onto such surface 22. Further, personalization data 12 may be printed onto such surface 22, where scrambled indicia 14, such as digital watermark, encoded images, or the like, may be embedded with such data 12. Physical security elements 28, such as magnetic strip, signature strip, hologram, IC chip (contact or contactless), or the like, may be added onto the substrate layer 20. If thermoplastic surface 34 is capable of receiving images, personalization data 12 can be printed onto such surface 34, where scrambled indicia 14, such as digital watermark, encoded images, or the like, may be embedded with such data 12. To protect thermoplastic surface 34 against abrasion, scratching, cuts, or the like, a protective layer or other suitable mechanisms, such as, for example, multiple, discrete regions of abrasion- resistant coating may be added over such surface 34.

In another aspect, the present invention is directed to a method of making a card comprising providing a substrate layer having a thermoplastic surface, providing a color- shifting film comprising a plurality of openings, providing a top layer having first and second thermoplastic surfaces, and laminating the color-shifting film between the thermoplastic surface of the substrate layer and the first thermoplastic surface of the top layer at elevated temperature and pressure. If thermoplastic surface 22 is capable of receiving images, the method may include printing security artwork 24, covert security features 26, and/or personalization data 12 onto such surface 22. Further, the method may include adding physical security elements 28 onto the substrate layer 20. If thermoplastic surface 34 is capable of receiving images, the method may include printing personalization data 12 onto such surface 34. If personalization data 12 are printed, the method may include embedding scrambled indicia 14 with the data 12.

The method may also include embossing indelible custom marks 44 and adding covert security features 48 onto the color-shifting film 40 and using color graphics 46 below the film 40.

Examples

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.

Comparative Examples A-C The sample for Comparative Example A was prepared as follows. A strip of clear-to- cyan color-shifting film (available from 3M Company, St Paul, MN) of about 85.5 mm long and 4.76 mm wide was made using an Aristmat 1625 cutter (model number KL4040, available from ARISTO Graphic Systeme, Hamburg, Germany). The strip was then laminated longitudinally between a CR80 composite card (available from Newbold Corporation, Rocky Mount, VA) and a CR80 poly(vinyl chloride) film using an Alantek

CL-99 laminator (available from Zebra Technologies Corporation, Vernon Hills, IL). CR80 is an industry code for cards and films that are of a dimension of about 85.5 mm in length and 54 mm in width. The lamination temperature and pressure were 295 ⁰F (-146 ⁰C) and 325 psi (-2.24 MPa) respectively, and the laminator was set at '6' for both cool and heat times. The composite card is a poly( vinyl chloride) core sandwiched between two pre-laminated overlay films of poly( vinyl chloride)/poly(ethylene terephthalate), with a total thickness of about 0.762 mm. The poly( vinyl chloride) film is about 25.4 μm thick. The samples for Comparative Examples B&C were prepared using the same procedure and materials except that before the strips of clear-to-cyan color-shifting film were made, in Comparative Example B the film was coated on both sides with a WB-50 primer (available from 3M Company, St Paul, MN) of about 10 nm thick, and in Comparative Example C the film was coated on both sides with a KRTY adhesive (available from

Transilwrap Company, Franklin Park, IL) of about 2 mil (50.8 μm) thick.

For each sample card, the poly( vinyl chloride) top film was cut open near one end of the strip of clear-to-cyan color- shifting film using a penknife. The strip was then slowly peeled off the card from the cut. None of the strips in the three sample cards showed evidence of tampering, such as tearing or other damage to the strip of color-shifting film.

Working Examples 1-9

The sample for Working Example 1 was prepared using the same procedure and materials as that for preparing the sample for Comparative Example A except that while the strip of clear-to-cyan color-shifting film was made the Aristmat cutter was programmed to make slits along the length of the strip. Two rows of slits of alternating slash (V) and back-slash ('V) about 20 mm apart were made, with one row at each side and one row being reverse to the other. The samples for Working Examples 2&3 were prepared using the same procedure and materials except that before the strips of clear-to- cyan color-shifting film were made and the slits were cut into the strips, in Working

Example 2 the film was coated on both sides with a WB-50 primer of about 10 nm thick, and in Working Example 3 the film was coated on both sides with a KRTY adhesive of about 2 mil (50.8 μm) thick.

The sample for Working Example 4 was prepared using the same procedure and materials as that for preparing the sample for Working Example 1 except that the slits made were alternating greater-than signs ('>') and less-than signs ('<') and that only one row was made along the centerline. The samples for Working Examples 5&6 were prepared using the same procedure and materials except that before the strips of clear-to- cyan color-shifting film were made and the slits were cut into the strips, in Working Example 5 the film was coated on both sides with a WB-50 primer of about 10 nm thick, and in Working Example 6 the film was coated on both sides with a KRTY adhesive of about 2 mil (50.8 μm) thick. The sample for Working Example 7 was prepared using the same procedure and materials as that for preparing the sample for Working Example 1 except that the slits made were crosshatchings ('x') and that only one row was made along the centerline. The samples for Working Examples 8&9 were prepared using the same procedure and materials except that before the strips of clear-to-cyan color-shifting film were made and the slits were cut into the strips, in Working Example 8 the film was coated on both sides with a WB-50 primer of about 10 nm thick, and in Working Example 9 the film was coated on both sides with a KRTY adhesive of about 2 mil (50.8 μm) thick.

For each sample card, the poly( vinyl chloride) top film was cut open near one end of the strip of clear-to-cyan color- shifting film using a penknife. The strip was then slowly peeled off the card from the cut. All of the strips in the nine sample cards showed evidence of tampering, e.g. tearing or damage to the strip of color-shifting film.

Working Examples 10-15 The sample for Working Example 10 was prepared using the same procedure and materials as that for preparing the sample for Working Example 4 except that the Aristmat cutter was further programmed to make a square opening of about 2.5 mm by 2.5 mm in the middle between any two neighboring slits. The samples for Working Examples 11&12 were prepared using the same procedure and materials except that before the strips of clear-to-cyan color-shifting film were made and the slits and the square openings were cut into the strips, in Working Example 11 the film was coated on both sides with a WB- 50 primer of about 10 nm thick, and in Working Example 12 the film was coated on both sides with a KRTY adhesive of about 2 mil (50.8 μm) thick.

The sample for Working Example 13 was prepared using the same procedure and materials as that for preparing the sample for Working Example 10 except that the circular openings of about 2.5 mm in diameter were made in place of the square openings. The samples for Working Examples 14&15 were prepared using the same procedure and materials except that before the strips of clear-to-cyan color-shifting film were made and the slits and the circular openings were cut into the strips, in Working Example 14 the film was coated on both sides with a WB-50 primer of about 10 nm thick, and in Working

Example 15 the film was coated on both sides with a KRTY adhesive of about 2 mil (50.8 μm) thick. For each sample card, the poly( vinyl chloride) top film was cut open near one end of the strip of clear-to-cyan color- shifting film using a penknife. The strip was then slowly peeled off the card from the cut. All of the strips in the six sample cards showed evidence of tampering, e.g. tearing or damage to the strip of color-shifting film. 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.

Claims

1. A card, comprising: a substrate layer having a thermoplastic surface, a color-shifting film comprising a plurality of openings, and a top layer having first and second thermoplastic surfaces, wherein the color- shifting film is laminated between the thermoplastic surface of the substrate layer and the first thermoplastic surface of the top layer at elevated temperature and pressure.

2. The card of claim 1, wherein security artwork is printed onto the thermoplastic surface of the substrate layer.

3. The card of claim 1, wherein covert security features are printed onto the thermoplastic surface of the substrate layer.

4. The card of claim 1, wherein physical security elements are added onto the substrate layer.

5. The card of claim 1, wherein personalization data are printed onto the second thermoplastic surface of the top layer and/or the thermoplastic surface of the substrate layer.

6. The card of claim 5, wherein scrambled indicia are embedded with the personalization data.

7. The card of claim 1 , wherein the color-shifting film is coated with a primer or an adhesive.

8. The card of claim 1, wherein the color-shifting film is clear-to-cyan color- shifting film.

9. The card of claim 1, wherein indelible custom marks are embossed onto the color- shifting film.

10. The card of claim 1, wherein color graphics are used below the color-shifting film.

11. The card of claim 1 , wherein covert security features are added onto the color-shifting film.

12. The card of claim 1, wherein the openings of the color-shifting film comprise slits.

13. The card of claim 1, wherein the thermoplastic surface of the substrate layer and the first thermoplastic surface of the top layer are fused together through the openings of the co lor- shifting film and wherein upon tampering at least one of the openings causes the film to show evidence of such tampering.

14. The card according to any preceding claim wherein the top layer comprise a laminate of three alternating layers of poly( vinyl chloride) and poly (ethylene terephthalate).

15. The card according to any preceding claim wherein the substrate layer comprises a poly( vinyl chloride) core attached with a laminate of three alternating layers of poly (vinyl chloride) and poly(ethylene terephthalate).

16. A method of making a card according to claim 1 comprising: providing a substrate layer having a thermoplastic surface, providing a color-shifting film comprising a plurality of openings, providing a top layer having first and second thermoplastic surfaces, and laminating the color-shifting film between the thermoplastic surface of the substrate layer and the first thermoplastic surface of the top layer at elevated temperature and pressure.

17. The method of claim 16 further comprising printing security artwork onto the thermoplastic surface of the substrate layer.

18. The method of claim 16 further comprising printing covert security features onto the thermoplastic surface of the substrate layer.

19. The method of claim 16 further comprising adding physical security elements onto the substrate layer.

20. The method of claim 16 further comprising printing personalization data onto the second thermoplastic surface of the top layer and/or the thermoplastic surface of the substrate layer.

21. The method of claim 20 further comprising embedding scrambled indicia with the personalization data.

22. The method of claim 16 further comprising coating the color-shifting film with a primer or an adhesive.

23. The method of claim 16, wherein the color-shifting film is clear-to-cyan color-shifting film.

24. The method of claim 16 further comprising embossing indelible custom marks onto the color-shifting film.

25. The method of claim 16 further comprising using color graphics below the color- shifting film.

26. The method of claim 16 further comprising adding covert security features to the color-shifting film.

27. The method of claim 16 further comprising making a plurality of openings in the color-shifting film.