Durable security laminate with hologram

• US 5,658,411 A
• Filed: 12/22/1995
• Issued: 08/19/1997
• Est. Priority Date: 01/19/1995
• Status: Expired due to Term

• Current Assignee: Minnesota Mining and Manufacturing Co (3M Company)
• Original Assignee: Minnesota Mining and Manufacturing Co (3M Company)
• Inventors: Faykish, Lynn E.
• Primary Examiner(s): Sells, James
• Assistant Examiner(s): Lorengo, J. A.
• Application Number:
  US08/577,133
• Time in Patent Office: 606 Days
• Field of Search: 156/209, 156/220, 156/234, 156/241, 156/233, 359/2, 428/142, 428/195, 428/204, 428/343, 428/206
• US Class Current: 156/233
• CPC Class Codes: B32B 2325/00 Polymers of vinyl-aromatic compounds, e.g. polystyrene
• CPC Class Codes: B32B 2327/06 PVC, i.e. polyvinylchloride
• CPC Class Codes: B32B 2333/12 Polymers of methacrylic acid esters, e.g. PMMA, i.e. polymethylmethacrylate
• CPC Class Codes: B32B 2367/00 Polyesters, e.g. PET, i.e. polyethylene terephthalate
• CPC Class Codes: B32B 27/08 of synthetic resin
• CPC Class Codes: B32B 27/302 comprising aromatic vinyl (co)polymers, e.g. styrenic (co)polymers
• CPC Class Codes: B32B 27/304 comprising vinyl halide (co)polymers, e.g. PVC, PVDC, PVF, PVDF
• CPC Class Codes: B32B 27/32 comprising polyolefins comprising vinyl (co)polymers or acrylic (co)polymers B32B27/30
• CPC Class Codes: B32B 27/36 comprising polyesters
• CPC Class Codes: B32B 7/12 using interposed adhesives or interposed materials with bonding properties
• CPC Class Codes: B42D 25/29 Securities; Bank notes
• CPC Class Codes: G02B 5/32 Holograms used as optical elements
• CPC Class Codes: G03H 2250/12 Special arrangement of layers
• CPC Class Codes: G03H 2250/35 Adhesive layer
• CPC Class Codes: G09F 3/0292 tamper indicating labels
• CPC Class Codes: Y10T 428/24364 with transparent or protective coating
• CPC Class Codes: Y10T 428/24802 Discontinuous or differential coating, impregnation or bond [e.g., artwork, printing, retouched photograph, etc.]
• CPC Class Codes: Y10T 428/24851 Intermediate layer is discontinuous or differential
• CPC Class Codes: Y10T 428/2486 with outer strippable or release layer
• CPC Class Codes: Y10T 428/24876 Intermediate layer contains particulate material [e.g., pigment, etc.]
• CPC Class Codes: Y10T 428/24917 : including metal layer
• CPC Class Codes: Y10T 428/31786 : Of polyester [e.g., alkyd, etc.]
• CPC Class Codes: Y10T 428/31797 : Next to addition polymer from unsaturated monomers
• CPC Class Codes: Y10T 428/31855 : Of addition polymer from unsaturated monomers
• CPC Class Codes: Y10T 428/31935 : Ester, halide or nitrile of addition polymer

Abstract

A security laminate comprising a protective layer having first and second surfaces, an embossing layer bonded to at least a portion of the second surface of the protective layer, a reflective layer bonded to at least a portion of the embossed layer/protective layer composite, an adhesion enhancing layer bonded to a portion of the reflective layer/embossed layer/protective layer composite, an adhesive bonded to at least a portion of the adhesion enhancing layer/reflective layer/embossed layer/protective layer composite wherein the bond between the reflective layer and the adhesion enhancing layer and the bond between the adhesion enhancing layer and the adhesive are each more tenacious than the bond between the reflective layer and the embossed layer and further wherein the bond between the adhesive and the adhesion enhancing layer is more tenacious than the bond between the adhesive and the reflective layer.

Claims

1. A method of rendering an article tamper resistant, comprising the steps of:

(a) providing a security laminate, comprising

(i) a protective layer having first and second surfaces;

(ii) an embossed layer having first and second surfaces, the first surface of the embossed layer bonded to at least a portion of the second surface of the protective layer;

(iii) a reflective layer having first and second surfaces, the first surface of the reflective layer bonded to at least a portion of the second surface of the embossed layer;

(iv) an adhesion enhancing layer bonded to portions of the second surface of the reflective layer; and

(v) an adhesive bonded to at least a portion of the adhesion enhancing layer/reflective layer/embossed layer/protective layer composite wherein the bond between the reflective layer and the adhesion enhancing layer and the bond between the adhesion enhancing layer and the adhesive are each more tenacious than the bond between the reflective layer and embossed layer and further wherein the bond between the adhesive and the adhesion enhancing layer is more tenacious than the bond between the adhesive and the reflective layer, and

(b) adhering the security laminate to the article in a desired location, so that delamination of the security laminate from the article renders the security laminate tamper-evident.

2. The method of claim 1, wherein the adhesion enhancing layer is comprised of ethylene acrylic acid.

3. The method of claim 1, wherein said embossed layer has an image visible to the unaided eye.

4. The method of claim 1, wherein said embossed layer is selected from the group consisting of a polystyrene, polymethyl methacrylate, and nitrocellulose-based resin.

5. The method of claim 1, wherein the protective layer and the reflective layer are at least partially transparent.

6. The method of claim 1, wherein the adhesive layer comprises heat activated adhesive.

7. The method of claim 1, wherein the adhesive layer comprises pressure sensitive adhesive.

8. The method of claim 1, wherein the reflective layer has a higher refractive index than the embossed layer.

9. The method of claim 1, wherein the reflective layer is selected from the group of bismuth trioxide, zinc sulfide, titanium dioxide, and zirconium oxide.

10. The method of claim 1, wherein the protective layer is selected from the group consisting essentially of polyester, polyvinyl chloride, polyolefin, and cellulose acetate films.

11. The method of claim 1, wherein the adhesion enhancing layer is invisible to the unaided eye.

12. The method of claim 1, wherein tampering by attempting to delaminate the security laminate from the article results in delamination of the reflective layer from the embossed layer substantially in the pattern of the adhesion enhancing layer.

13. The method of claim 12, wherein step (b) includes applying the security laminate to a document.