Patent EP0175513A2 successfully refreshed from Google Patents.
EP0175513A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Tamper resistant security film
Assignee: 3M Co
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Filing: 1985-09-02
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Granted: —
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Expires: 2005-09-02
Abstract
Abstract 57 Security film (10, 10 1 ) comprising a monolayer of transparent microspheres (11) supported in a thin layer of binder material (12), a pressure-sensitive adhesive layer (15) coated on the layer of binder material, and at least one patterned layer (16, 17) disposed between the pressure-sensitive adhesive and binder layers. The patterned layer (16, 17) has differential adhesion to the pressure-sensitive adhesive layer (15) and the binder layer (12). Upon attempted elevated-temperature removal of the film from a substrate, the film splits, with part of the film remaining on the substrate and part being removed.
Inventors
- 👤 Wu Shyong C/O Minnesota Mining And Li
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-07 22:09
CPC Classifications
G; G03; G03C; G03C1/00; G03C1/74; B; B42; B42D; B42D25/00; B42D25/20; B42D25/29; B42D25/40; B42D25/45; B42D25/465; B42D25/47; C; C09; C09J; C09J7/00; C09J7/20; G02; G02B; G02B5/00; G02B5/12; G02B5/126; G02B5/128; G09; G09F; G09F3/00; G09F3/02; G09F3/0291; G09F3/0292; B42D2033/04; B42D2033/18; Y; Y10; Y10S; Y10S428/00; Y10S428/916
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
146 words
A security film comprising a monolayer of transparent microspheres supported in a thin layer of binder material that comprises an acrylic low-molecular-weight polymer soluble in a nonpolar solvent and a pressure-sensitive adhesive coated onto the binder material; characterized in that at least a first patterned layer disposed between the layer of pressure-sensitive adhesive and binder material and covers a portion of the interface between the two layers, said patterned layer comprising either a dye having lower adhesion to the binder material than to the pressure-sensitive adhesive or a nonpolar thermoplastic resin promoting adhesion between the binder material and pressure-sensitive adhesive such that upon exposure of the complete film to an elevated temperature of 100°C or more, the pressure-sensitive adhesive separates from the binder material in areas covered by the dye, but tends to remain adhered to the binder material in areas covered by the adhesion-promoting resin.
Claim 2
Dependent Claim
146 words
A security film comprising a monolayer of transparent microspheres supported in a thin layer of binder material that comprises an acrylic low-molecular-weight polymer soluble in a nonpolar solvent and a pressure-sensitive adhesive coated onto the binder material; characterized in that at least a first patterned layer disposed between the layer of pressure-sensitive adhesive and binder material and covers a portion of the interface between the two layers, said patterned layer comprising either a dye having lower adhesion to the binder material than to the pressure-sensitive adhesive or a nonpolar thermoplastic resin promoting adhesion between the binder material and pressure-sensitive adhesive such that upon exposure of the complete film to an elevated temperature of 100°C or more, the pressure-sensitive adhesive separates from the binder material in areas covered by the dye, but tends to remain adhered to the binder material in areas covered by the adhesion-promoting resin.
Claim 3
Dependent Claim
34 words
A security film of claim 1 which includes both a first patterned layer comprising said dye and a second patterned layer comprising said nonpolar thermoplastic resin, said layers having overlapping portions and non-overlapping portions.
Claim 4
Dependent Claim
18 words
A security film of claim 1 or 2 in which the pressure-sensitive adhesive is applied from a latex.
Claim 5
Dependent Claim
17 words
A security film of any of claims 1-3 in which the pressure-sensitive adhesive comprises an acrylic polymer.
Claim 6
Dependent Claim
18 words
A security film of any of claims 1-4 in which the nonpolar thermoplastic resin comprises an acrylic polymer.
Claim 7
Dependent Claim
25 words
A security film of any of claims 1-5 in which the dye is an ionic dye dispersed in a vehicle that comprises an acrylic polymer.
References Cited (Backward Citations)
No citation records indexed.
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