EP0419241A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Transparent overlay for protecting a document from tampering
Assignee: 3M Co
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Filing: 1990-09-19
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Granted: —
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Expires: 2010-09-19
Abstract
Abstract A transparent overlay that can protect a document from tampering has a transparent cover sheet, a layer of hot-melt adhesive over one surface of the transparent cover sheet, and a polymeric image-receiving layer over the exposed face of said hot-melt adhesive layer. The transparent cover sheet can be a simple thermoplastic film but preferably is retroreflective sheeting which can bear a pattern or legend that is noticeable only when viewed retroreflectively. When the polymeric image-receiving layer is dye-receptive, it can be imaged by using a thermal printing head with a dye-donor element. A preferred polymeric image-receiving layer that is dye-receptive is chlorinated poly(vinylchloride).
Inventors
- 👤 Douglas K. C/O Minnesota Mining And Fossum
- 👤 Susan K. C/O Minnesota Mining And Jongewaard
- 👤 John W. C/O Minnesota Mining And Mcconville
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-07 21:30
CPC Classifications
B; B41; B41M; B41M7/00; B41M7/0027; B41M5/00; B41M5/50; B41M5/52; B41M5/5254; B42; B42D; B42D25/00; B42D25/20; B42D25/29; Y; Y10; Y10S; Y10S283/00; Y10S283/904; Y10T; Y10T428/00; Y10T428/26; Y10T428/263; Y10T428/264
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
77 words
A transparent overlay by which a document can be protected from tampering, characterized in that said overlay comprises: (a) a transparent flexible cover sheet (b) a layer of hot-melt adhesive over one surface of said transparent cover sheet, which adhesive has a glass transition temperature of at least about -15°C, and (c) a polymeric image-receiving layer over the exposed face of said hot-melt adhesive layer, which image-receiving layer is no more than about 50 microns in thickness.
Claim 2
Dependent Claim
77 words
A transparent overlay by which a document can be protected from tampering, characterized in that said overlay comprises: (a) a transparent flexible cover sheet (b) a layer of hot-melt adhesive over one surface of said transparent cover sheet, which adhesive has a glass transition temperature of at least about -15°C, and (c) a polymeric image-receiving layer over the exposed face of said hot-melt adhesive layer, which image-receiving layer is no more than about 50 microns in thickness.
Claim 3
Dependent Claim
50 words
A transparent overlay as defined in claim 1 further characterized in at least one of the following: (a) said cover sheet is a thermoplastic film; or (b) said cover sheet is retroreflective sheeting which incorporates means for bearing a pattern or legend that is readily legible only when viewed retroreflectively.
Claim 4
Dependent Claim
109 words
A transparent overlay as defined in claim 1 further characterized in at least one of the following: (a) the major polymeric component of said image-receiving layer is selected from poly(vinylchloride)s, polyesters, cellulosic derivatives, polyvinylpyrollidones, polycarbonates, butyral vinyl acetates, acrylates, methacrylates, and styrene/acrylonitrile copolymers; or (b) the glass transition temperature of the major polymeric component of said image-receiving layer is from about 60° to about 150°C; or (c) said image-receiving layer comprises chlorinated poly(vinylchloride) having a glass transition temperature no lower than about 80°C, and an inherent viscosity of about 0.4 to about 1.5; or (d) the thickness of said image-receiving layer is from about 8 to about 25 microns.
Claim 5
Dependent Claim
87 words
A transparent overlay as defined in claim 1 further characterized in at least one of the following: (a) said hot-melt adhesive has a glass transition temperature of from about 40°C to about 100°C; or (b) said hot-melt adhesive comprises a linear, random copolyester of one or more aromatic dibasic acids and one or more aliphatic diols, modified with up to about 30 mole percent of one or more aliphatic dibasic acids; or (c) the thickness of said hot-melt adhesive is from about 25 to about 200 microns.
Claim 6
Dependent Claim
23 words
A transparent overlay as defined in claim 1 and further comprising a barrier layer between said hot-melt adhesive layer and said cover sheet.
Claim 7
Dependent Claim
80 words
A document having a transparent overlay characterized in that said overlay comprises: (a) a transparent cover sheet, (b) a layer of hot-melt adhesive over one surface of said transparent covering, which adhesive has a glass transition temperature of at least about -15°C, and (c) a polymeric image-receiving layer over the exposed face of said hot-melt adhesive layer, which image-receiving layer is no more than about 50 microns in thickness. said overlay being bonded to the document by said hot-melt adhesive.
Claim 8
Dependent Claim
80 words
A document having a transparent overlay characterized in that said overlay comprises: (a) a transparent cover sheet, (b) a layer of hot-melt adhesive over one surface of said transparent covering, which adhesive has a glass transition temperature of at least about -15°C, and (c) a polymeric image-receiving layer over the exposed face of said hot-melt adhesive layer, which image-receiving layer is no more than about 50 microns in thickness. said overlay being bonded to the document by said hot-melt adhesive.
Claim 9
Dependent Claim
26 words
A document as defined in claim 6 further characterized in that said image-receiving layer bears an image which is protected from tampering by the transparent overlay.
Claim 10
Dependent Claim
57 words
A document as defined in claim 7 further characterized in at least one of the following: (a) said cover sheet comprises retroreflective sheeting; or (b) said cover sheet comprises retroreflective sheeting that bears a pattern or legend that is readily legible only when the document is viewed retroreflectively; or (c) said cover sheet is a thermoplastic film.
Claim 11
Dependent Claim
97 words
Method of protecting a document from tampering, characterized in that said method comprises: 1) creating a transparent overlay comprising (a) a transparent cover sheet, (b) a layer of hot-melt adhesive over one surface of said transparent cover sheet, which adhesive has a glass transition temperature of at least about -15°C, and (c) a polymeric image-receiving layer over the exposed face of said hot-melt adhesive layer, which image-receiving layer is no more than about 50 microns in thickness; 2) forming an image on said image-receiving layer; and 3) adhering said overlay by its hot-melt adhesive to the document.
Claim 12
Dependent Claim
97 words
Method of protecting a document from tampering, characterized in that said method comprises: 1) creating a transparent overlay comprising (a) a transparent cover sheet, (b) a layer of hot-melt adhesive over one surface of said transparent cover sheet, which adhesive has a glass transition temperature of at least about -15°C, and (c) a polymeric image-receiving layer over the exposed face of said hot-melt adhesive layer, which image-receiving layer is no more than about 50 microns in thickness; 2) forming an image on said image-receiving layer; and 3) adhering said overlay by its hot-melt adhesive to the document.
References Cited (Backward Citations)
No citation records indexed.
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