MULTI-LAYER FILM FOR FOG-FREE MIRROR

Abstract

The present invention includes a multi-layer film that may be applied to reflective surfaces in order to reduce fogging, wherein the multi-layer film also serves as a protective covering. In one embodiment, a multi-layer film that may be applied to a mirror or other reflective surface includes a first layer of PET (polyester), a second layer of PSA (pressure sensitive adhesive) or thermally activated acrylic, a third layer of PET transparent substrate, a fourth layer of an anti-fog film, which is which is a chemical mixed coating and a fifth layer of PE (polyethylene) acrylic electrostatic protective film.

Claims

1. A reflective surface covering comprising: a reflective substrate; and a multi-layer film comprising: a first layer of thermoplastic resin; a layer of thermally activated adhesive; a second layer of thermoplastic resin; a layer of an anti-fog film; and a layer of polyethylene acrylic electrostatic protective film.

2. The reflective surface covering set forth in claim 1, wherein said first layer of thermoplastic resin has a thickness in the range of 48 and 52 μm.

3. The reflective surface covering set forth in claim 1, wherein said layer of adhesive has a thickness in the range of 8 and 10 μm.

4. The reflective surface covering set forth in claim 1, wherein said second layer of polymeric resin includes a thickness in the range of 95 and 105 μm.

5. The reflective surface covering set forth in claim 1, wherein said layer of anti-fog film has a thickness in the range of 10 and 12 μm.

6. The reflective surface covering set forth in claim 1, wherein said layer of polyethylene acrylic electrostatic protective film has a thickness in the range of 40 and 50 μm.

7. The reflective surface covering set forth in claim 1, wherein said first layer of thermoplastic resin is selected from the group consisting of polyethylene terephthalate, polyurethane and polyurethane.

8. The reflective surface covering set forth in claim 7, wherein said first layer of thermoplastic resin includes at least one additive selected from the group consisting of a hydrophilic polymer, an isocyanate prepolymer with free isocyanate groups, an organic solvent solution of a hydrophilic polyol, and a surfactant having isocyanate-reactive functionality.

9. The reflective surface covering set forth in claim 1, wherein said second layer of thermoplastic resin is selected from the group consisting of polyethylene terephthalate, polyurethane and polyurethane.

10. The reflective surface covering set forth in claim 9, wherein said second layer of thermoplastic resin includes at least one additive selected from the group consisting of a hydrophilic polymer, an isocyanate prepolymer with free isocyanate groups, an organic solvent solution of a hydrophilic polyol, and a surfactant having isocyanate-reactive functionality.

11. The reflective surface covering set forth in claim 1, wherein said first thermoplastic polymeric resin layer is positioned between said thermally activated adhesive layer and the second thermoplastic polymeric resin layer.

12. The reflective surface covering set forth in claim 1, wherein said second thermoplastic polymeric resin layer forms the top surface of the multi-layer film.

13. The reflective surface covering set forth in claim 1, wherein said layer of polyethylene acrylic electrostatic protective film forms the top surface of the multi-layer film.

14. A method of preparing a reflective surface covering comprises: providing a reflective substrate and a multi-layer film comprising: a protective layer; and an anti-fog complex comprising: a first thermoplastic polymeric resin layer; a thermally activated adhesive layer; a second thermoplastic polymeric resin layer; laminating the multi-layer film and the reflective substrate together to form a laminated composite; maintaining the laminated composite in ambient conditions for a time sufficient to permit solidification of the multi-layer film; removing the protective layer from the laminated composite to expose the anti-fog complex; and performing a post-lamination cleaning cycle.

15. The method of preparing a reflective surface covering set forth in claim 14, wherein said multi-layer film and the reflective substrate are laminated together at a pressure of from about 0.66 pounds per square inch to about 1.54 pounds per square inch.

16. A method for manufacturing an anti-fog film comprising the steps of: providing a sheet of PET material having a first side and a second side; adding an anti-fog solvent coating with micro gravure onto said first side of said sheet of PET material thermally curing said coated PET material with said anti-fog solvent; adding an acrylic adhesive on said second side of the PET sheet to form a composite film; thermally curing said composite film; attaching a PET release film to said acrylic adhesive; attaching a metallocene protection film to said anti-fog coating; and winding said composite film onto a plastic tube.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0019] These and other features, aspects, and advantages of the present invention will become better understood with regard to the following description, appended claims, and accompanying drawings where:

[0020] FIG. 1 is an exploded view of one embodiment of a multi-layer film that may be applied to a mirror or reflective surface, wherein the multi-layer film includes a first layer of PET (polyester), a second layer of PSA (pressure sensitive adhesive) acrylic, a third layer of PET transparent substrate, a fourth layer of which is a chemical mixed anti-fog coating and a fifth layer of PE (polyethylene) acrylic electrostatic protective film.

DETAILED DESCRIPTION OF THE INVENTION

[0021] Overview

[0022] Generally, the present invention provides a reflective surface covering comprising: a reflective substrate; and a multi-layer film comprising: a first thermoplastic polymeric resin layer; a thermally activated adhesive layer; and a second thermoplastic polymeric resin layer; and an anti-fog coating. The thickness of the adhesive layer is preferably linked to the thickness of the thickness of the anti-fog coating. For example, if the anti-fog coating layer has a maximum thickness of about 12 μm, then the thickness ratio between the thermally activated adhesive layer and the anti-fog coating layer is preferably from about 0.66:1. Alternatively, if the thickness of the adhesive layer is a minimum of 8 μm and the anti-fog coating layer has a maximum thickness of 10 μm, then the thickness ratio between the adhesive layer and the anti-fog coating is about 1:1.

TABLE-US-00001 Thickness Classification Unit For Bath Remark Ratio Protection μm 45 ± 5 Anti fog coating μm 11 ± 1 AF 1 Base Film μm 100 ± 5  PET Adhesive μm  9 ± 1 ACR 0.8~0.83 Liner μm 50 ± 2 Total μm 215 ± 14

[0023] Multi-Layer Film Structure

[0024] The present invention includes, in a first embodiment, a multi-layer film that may be applied to a mirror or other reflective surface includes a first layer of PET (polyethylene terephthalate or polyester—also referred to herein as the ‘first polymeric resin layer’) preferably having a thickness in the range of 48 and 52 μm, a second layer of PSA (pressure sensitive adhesive) or thermally activated acrylic preferably having a thickness in the range of 8 and 10 μm, a third layer of PET transparent substrate (also referred to herein as the ‘second polymeric resin layer’) preferably having a thickness in the range of 95 and 105 μm, a fourth layer of an anti-fog film, which is preferably a chemical mixed coating preferably having a thickness in the range of 10 and 12 μm, and a fifth layer of PE (polyethylene) acrylic electrostatic protective film, which preferably has a thickness in the range of 40 and 50 μm.

[0025] The anti-fog layer may be a film or coating. Some examples of anti-fog compositions include a polymer which is polyvinylpyrrolidone, polydimethylacrylamide or a polyvinylprrolidone copolymer with a polymerizable alpha olefin free of functional groups reactive with isocyanates; a polyisocyanate prepolymer; a surfactant which will chemically bond to a reaction product of the polymer and prepolymer, and an organic solvent to form a solution of the foregoing ingredients. Other examples include substrates having an anti-fog transparent coating comprising the reaction product of polyvinylpyrrolidone, a polyvinylpyrrolidone copolymer with a polymerizable alpha olefin free of functional groups reactive with isocyanates or polydimethylacrylamide with a polyisocyanate prepolymer, said reaction product being chemically bound to a surfactant. Both nonionic and anionic surfactants may be used in the same coating composition to good effect. In another embodiment, the anti-fog coating consists essentially of a copolyester binder and an anionic surfactant, wherein the surfactant contains less than about 0.5 weight percent of a fluorosurfactant. Another example of an antifogging film may include a two-package coating agent for forming an antifogging film. This coating agent contains a first coating agent comprising an isocyanate containing an isocyanate group; and a second coating agent comprising (a) a polyol component comprising at least a water-absorbing polyol and a hydrophobic polyol and (b) a surfactant comprising a group that is reactive with the isocyanate group. It is possible to form an antifogging film by a method including the steps of mixing the first and second coating agents together to prepare a coating agent; applying the coating agent to the substrate to form a precursory film on the substrate; and hardening the precursory film under room temperature or heating into the antifogging film. Other types of anti-fogging films, coatings and agents are described and disclosed in the above-referenced patent documents (patents and published applications), all of which are incorporated herein by reference, in their entireties. Similarly, anti-fog films, coatings and agents are commercially available worldwide, and any suitable anti-fog films, coatings or agents may be used. One particularly preferred Anti-Fog film is commercially manufactured and sold by SEWHA P&C Co., Ltd.

[0026] Other types of thermoplastic resins may be used, as well, in place of the first layer of PET and the third layer of PET. For example, polyurethane or a polyurethane based layer may be used, and may include a hydrophilic polymer, an isocyanate prepolymer with free isocyanate groups, an organic solvent solution of a hydrophilic polyol and a surfactant having isocyanate-reactive functionality. One example of suitable polyurethane based layers may be found in U.S. Pat. No. 5,877,254, which is also incorporated herein by reference.

[0027] It should be understood that different embodiments may have a different configuration of layers with respect to one another. For some versions of the present invention, each layer of the multi-layer film has a particular arrangement. In some embodiments, the first thermoplastic polymeric resin layer is positioned between the thermally activated adhesive layer and the second thermoplastic polymeric resin layer. In those embodiments wherein the multi-layer film further comprises a protective layer, the protective layer is adjacent to the second thermoplastic polymeric resin layer. In other embodiments wherein the multi-layer film further comprises a protective layer, there may be no intervening layers between the protective layer and the second thermoplastic polymeric resin layer.

[0028] In certain embodiments, the second thermoplastic polymeric resin layer forms the top surface of the multi-layer film. In those embodiments wherein the multi-layer film comprises a protective layer, the protective layer preferably forms the top surface of the multi-layer film.

[0029] It is also contemplated that the first thermoplastic polymeric resin layer may be positioned between the thermally activated adhesive layer and the second thermoplastic polymeric resin layer, such that there are no intervening layers between the first thermoplastic polymeric resin layer and the thermally activated adhesive layer. Alternatively, the first thermoplastic polymeric resin layer may be positioned between the thermally activated adhesive layer and the second thermoplastic polymeric resin layer, such that there are no intervening layers between the first thermoplastic polymeric resin layer and the second thermoplastic polymeric resin layer. Optionally, the first thermoplastic polymeric resin layer may be positioned between the thermally activated adhesive layer and the second thermoplastic polymeric resin layer, such that there are no intervening layers between the first thermoplastic polymeric resin layer and the second thermoplastic polymeric resin layer or any intervening layers between the first thermoplastic polymeric resin layer and the thermally activated adhesive layer.

[0030] In certain embodiments, each layer of the anti-fog complex has a particular arrangement. In some embodiments, the first thermoplastic polymeric resin layer is positioned between the thermally activated adhesive layer and the second thermoplastic polymeric resin layer of the anti-fog complex. In some embodiments, the second thermoplastic polymeric resin layer forms the top surface of the anti-fog complex. Optionally, the anti-fog complex may include no intervening layers between the first thermoplastic polymeric resin layer and the thermally activated adhesive layer. It is also foreseen that the anti-fog complex may include no intervening layers between the first thermoplastic polymeric resin layer and the second thermoplastic polymeric resin layer. In some embodiments, the anti-fog complex does not contain any intervening layers between the first thermoplastic polymeric resin layer and the second thermoplastic polymeric resin layer or any intervening layers between the first thermoplastic polymeric resin layer and the thermally activated adhesive layer.

[0031] The invention will be described in greater detail by way of specific examples. The following examples are offered for illustrative purposes and are not intended to limit the invention in any manner. Those skilled in the art will readily recognize a variety of noncritical parameters, which can be changed or modified to yield essentially the same results.

Example 1

[0032]

TABLE-US-00002 The Project Unit No Specifications Detection value Test die method Thickness PE film μm 40 ± 3 40 ASTM D374 PET substrate 100 ± 3  100 Anti-fog layer + 120 ± 5  121 PET substrate + PSA PET discrete 50 ± 3 50 membrane The PSA-layer Initial value N/25 mm >10 >10 ASTM D3330 stripping After the high N/25 mm >10 >10 force (For the temperature and SUS, 180° the high 300 mm/min humidity Fog degree % ≤4 1.41 ASTM D1003 Light transmittance ≥89 91.43 Anti-fog nature / For 20 times Qualified The 100° C. boiling water test Apables Qualified Note 1, High temperature and high wet conditions: 60° C. 90% RH 72 hours. The 2, can adjust the substrate thickness and rubber layer stripping force according to the customer requirements.

[0033] Manufacturing Method

[0034] In one embodiment, a method of preparing a reflective surface covering comprises: a) providing a reflective substrate and a multi-layer film comprising: a protective layer; and an anti-fog complex comprising: a first thermoplastic polymeric resin layer; a thermally activated adhesive layer; a second thermoplastic polymeric resin layer; b) laminating the multi-layer film and the reflective substrate together to form a laminated composite; c) maintaining the laminated composite in ambient conditions for a time sufficient to permit solidification of the multi-layer film; d) removing the protective layer from the laminated composite to expose the anti-fog complex; and e) performing a post-lamination cleaning cycle. In some embodiments, the multi-layer film and the reflective substrate are laminated together at a pressure of from about 0.66 pounds per square inch (psi) to about 1.54 psi.

[0035] One example of the manufacturing process involves the following steps: 1) providing a sheet of PET material and adding an anti-fog solvent coating with micro gravure onto a first side of the PET material, and thermally curing the coated PET material with the anti-fog solvent; 2) adding an acrylic adhesive on the second side (the opposite side of the anti-fog solvent coating) of the PET sheet, and thermally curing the composite; 3) attaching a PET release film to the acrylic adhesive side; 4) attaching a metallocene protection film to the anti-fog coating; and 5) winding the resulting composite film onto a plastic tube. The rolled film may then be applied in a separate process to a mirror or other reflective surface.

[0036] Although the present invention has been described in considerable detail with reference to certain preferred versions thereof, other versions are possible. Therefore, the spirit and scope of the appended claims should not be limited to the description of the preferred versions contained herein. All features disclosed in this specification may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise. Thus, unless expressly stated otherwise, each feature disclosed is one example only of a generic series of equivalent or similar features.