NZ616261B2 - Decorated thermoplastic film and methods for making the same - Google Patents

Abstract

Disclosed herein are variably decorative thermoplastic films having a graphic design saturated into a laminate or coated substrate, which can be pre-formed using heat and pressure and then placed in injection molds for product molding without impacting the quality of the graphics. In one embodiment the thermoplastic film comprises: (i) a substrate having a first surface and a second surface located opposite the first surface, the substrate having a graphic saturated into the first surface and the first surface comprising a film layer comprising polyvinyl fluoride (PVF); and (ii) a thermoplastic composition in contact with the second surface of the substrate, wherein the thermoplastic composition does not contact the first surface of the substrate. the thermoplastic film comprises: (i) a substrate having a first surface and a second surface located opposite the first surface, the substrate having a graphic saturated into the first surface and the first surface comprising a film layer comprising polyvinyl fluoride (PVF); and (ii) a thermoplastic composition in contact with the second surface of the substrate, wherein the thermoplastic composition does not contact the first surface of the substrate.

Description

Decorated plastic Film and s for Making the Same This application claims priority to U.S. Provisional Application No. 61/450,312, filed March 8, 2011, the contents ofwhich are hereby orated by reference in its entirety.

Field of the Invention The invention pertains to rendering dispersion dye graphics into the surface of film uctions which are then used with in-mold decoration operations during injection molding.

More specifically, the invention pertains to substantially clear dye-receptive films laminated over opaque substrates, or coated substrates, to achieve film constructions that are ideal for supporting dye—rendered graphics. After printing, the films can be pre-formed using heat and pressure and then placed in injection molds for product g with decorated surfaces without impacting the quality of the graphics.

Background of the Invention Decorative thermoplastics have been widely used as protective coverings from flooring to electronics. Thermoplastics can be melted and molded, making them le for virtually any application where a protective covering is desired.

There are various processes commonly used to inlay a decoration onto thermoplastics.

These processes, such as in-mold labeling (IML), film insert molding (F1M) and in~mold decoration (IMD), involve printing a film with a decorative graphic; inserting the film into the injection mold; and injecting a thermoplastic molding compound behind the film. When the film is removed from the injection mold, the printed film has theoretically adhered to the molding nd and acts as the decorative first e. The printing s itself typically involves methods such as silk-screening, rotary screening, flexographic printing techniques and offset lithography printing, among others.

In practice, the combination of the printing processes and inlay processes described above can result in a graphic that is not durable and can be easily damaged, abraded or chemically removed from the printed e of the finished film. In order to avoid such W0 2012/122360 2012/028244 potential damage, standard ce has been to print the backside of a arent film, and then place the film in the mold with the graphic facing the inside of the mold. Molding compound is then shot against the graphically printed and coated e. This yields a graphic that is protected by a layer of transparent plastic film on the first surface.

However, printed graphics cannot easily e the conditions inside the injection mold, which can be up to 12,000 psi and 600f. Graphics are burned and sheared off the surface of the films that are facing the inside of the mold, when the hot resins flow in through the injection gates. Methods have been developed for specialized gating that will allow specific areas Within the mold to support film insert molding without destroying the graphics, as long as specialized and c processing parameters are maintained.

Another attempt to s the problem of graphic survival inside the mold is to coat the graphic with a high temperature coating that will protect the c from the hot molding compounds that are injected into the mold and onto the cally printed surface that has been coated. However, the coatings used to protect the graphics cannot create a miscible bond with the hot flowing molding compounds made up of thermoplastic resins. In fact these protective coatings generally interfere with and defeat a quality lamination bond between the decorated films and the hot molding compounds. Therefore, specialized adhesion ers have been developed that will help to e the bond between the protective coatings on the in—mold decorative films and the hot flowing resins. A series of adhesion promoters have been developed specific to each of the thermoplastic resins and protective coatings used in molding the t.

However, delarnination between the decorative film and the molded parts remains a challenge.

A further obstacle for printed thermoplastics is that the printed and coated films are often therrnoformed to conform to the shape of the mold before they are inserted into the injection mold. Therefore the film printing must also be able to survive the heating and stretching of the film over profiles and complex curves during the thermoforming process. Inks that can go through a vacuum forming s, “Formable inks”, have been developed. However, because these le ink systems are pigment-based inks and printed to the surface of the films, they can only withstand film stretching of less than half inch before the graphic print thins and degrades. This failure severely limits the scope of form factors that can be decorated using the traditional in-mold decoration s in practice today. 1001024141 * 5 MAR 20% There exists a need in the art for a variably decorated thermoplastic film which retains its graphic throughout the molding process, as well as throughout the use of the film to which it is applied. [0009A] Reference to any prior art in the specification is not, and should not be taken as, an acknowledgment, or any form of suggestion, that this prior art forms part of the common general knowledge in New Zealand or any other jurisdiction or that this prior art could reasonably be expected to be ascertained, understood and regarded as relevant by a person skilled in the art. [0009B] As used herein, except where the context requires otherwise, the term "comprise" and variations of the term, such as ”comprising", "comprises" and "comprised", are not intended to exclude other additives, components, integers or steps.

Summary of the Invention It is therefore an object of the invention to provide a variably decorated thermoplastic film having a durable imprinted graphic and s of making the same.

In certain embodiments, the present invention is directed to a ted plastic film comprising: (i) a substrate having a first surface and a second surface located te the first e, the first surface having a graphic saturated into the substrate; and the first surface comprising a film layer comprising polyvinyl fluoride (PVF); and (ii) a thermoplastic composition in contact with the second surface of the substrate, wherein the thermoplastic composition does not contact the first surface of the substrate.

[0012] In certain embodiments, the present invention is ed to a decorated thermoplastic film comprising: (i) a coated substrate having a first surface and a second surface d te of the first surface, the first surface having a graphic saturated into the ate; and (ii) a thermoplastic composition in contact with the second surface of the coated substrate, wherein the thermoplastic composition does not contact the first e of the coated substrate.

[0013] In certain embodiments, the present invention is directed to a decorated thermoplastic film comprising: (i) a laminate substrate having a first e and a second surface located opposite of the first surface, the first surface having a graphic ted into the substrate; and (ii) a thermoplastic composition in contact with the second surface of the te substrate, wherein the thermoplastic composition does not t the first surface of the laminate substrate. 1001024141 “ 5 MAR 2015 In certain embodiments, the present invention is directed to a decorated thermoplastic film sing: (i) a substrate comprising from about 5% to about 25% common- light wavelength light transmission, the substrate having a first surface and a second surface located opposite of the first surface, the first surface having a graphic saturated into the substrate; and (ii) a thermoplastic ition in t with the second e of the substrate, wherein the thermoplastic composition does not contact the first surface of the ate.

In certain embodiments, the present invention is directed to a method for making a decorated thermoplastic film comprising: (i) rendering a graphic into a ate having a first surface and a second surface d opposite of the first surface, wherein the c is rendered into the first e of the substrate; and the first surface further comprises a film layer comprising polyvinyl fluoride (PVF); (ii) placing the substrate in a mold, n the first surface of the substrate is positioned to be in contact with the mold; and (iii) injecting a thermoplastic composition into the mold onto the second surface of the substrate.

In certain embodiments, the present invention is directed to a method for making a decorated thermoplastic film sing: (i) rendering a graphic into a laminate substrate having a first surface and a second surface located opposite of the first surface, wherein the graphic is rendered into the first surface of the laminate substrate; (ii) placing the laminate substrate in a mold, wherein the first surface of the laminate ate is positioned to be in contact with the mold; and (iii) injecting a thermoplastic composition into the mold onto the second surface of the laminate substrate.

In certain embodiments, the present invention is directed to a method for making a decorated film comprising: (i) rendering a graphic into a coated substrate comprising a first surface and a second surface located opposite of the first e, wherein the graphic is rendered into the first surface of the coated substrate; (ii) placing the coated substrate in a mold, wherein the first surface of the coated substrate is positioned to be in t with the mold; and (iii) injecting a thermoplastic composition into the mold onto the second surface of the coated substrate.

In certain embodiments, the t invention is directed to a method for making a decorated thermoplastic film comprising: (i) rendering a graphic into a substrate comprising from about 5% to about 25% common-light wavelength light transmission, the substrate having a first surface and a second surface located opposite of the first surface, wherein the graphic is rendered into the first surface of the coated substrate; (ii) placing the substrate in a mold, wherein l001024l41 - Eat/1R 20l5 the first surface of the substrate is oned to be in contact with the mold; and (iii) injecting a thermoplastic composition into the mold onto the second surface of the substrate.

In describing the present invention, the ing terms are to be used as indicated below. As used herein, the singular forms "a, H H an," and "the" include plural references unless the context clearly indicates otherwise.

As used herein, the term "durable" means resistant to normal wear and tear, scratches, removal, color fading, etc.

As used herein, the terms ”ink", "dye" and nk" are used interchangeably. 2012/028244 As used herein, the terms “rendered” or “rendering” and “saturated” or “saturating”, respectively, are used interchangeably.

Detailed Description The present invention provides a method for making a ted thermoplastic film through the process of injection molding using a decorated film inserted into the mold. The graphic is printed into first surface (facing the eye) of the film . The method produces films that will present bright, full color, photo quality graphics unmuted by layers of protective plastics, yet the graphic can meet durability requirements for OEM manufacturing of consumer products.

One ofthe benefits of the present invention is that the resulting decorated thermoplastic films will not lose their color and brightness over time, the graphic cannot be hed offthe surface, and the decorative thennoplastics can be produced using any printing method suitable for injection g processes, such as, e.g;, digital and analog printing methods.

The films of the present invention are particularly suitable when a design having a high resolution is required, as the films of the present invention maintain the high resolution of their cs imprinted in them.

An additional benefit of the present invention is that the film inserts do not require tive back-coatings over the cs in order to t survival of the graphics during the molding process. The unprinted side (second surface) of the film ate, onto which the hot flowing resins are injected, protects the first surface graphic during injection molding. As the ted side is the only side in contact with the thermoplastic resin, the printed side does not require a protective coating. Therefore, the s of the present invention does not create bonding issues between the ted films and the molding compounds, as the molding compounds are shot onto naked, unprinted film surfaces. The present invention allows the selection of films and resins from compatible categories of thermoplastic materials commonly used in injection molding. Then, after printing the films, combining these materials under the conditions prevailing in the common injection g process produces an inviolable miscible and/or adhesive bond between the decorated films inserted into the molds and the molding compounds shot in behind them.

W0 2012/122360 PCT/U82012/028244 In certain embodiments, the substrate used for the films comprises a thermoplastic resin le for injection molding, such as, e.g., polycarbonate homopolymers, copolycarbonates, acrylonitrile-butadiene—styrene resins (ABS), styrene/acrylonitrile (SAN), polyamides, thermoplastic polyurethane, polymethylmethacrylate (PMMA Acrylics), thermoplastic urethane (TPU), Thermoplastic Elastomer (TPE), polyvinyl fluoride (PVF), poly vinylidine fluoride (PVDF), blends of polycarbonate, resins thereof, or mixtures thereof. In preferred embodiments, the laminate ate comprises a polycarbonate resin.

In certain embodiments, the substrate used for the films comprises multiple film layers, which can include, e.g., transparent layers, opaque layers, or a combination thereof.

In other embodiments, the substrate comprises a single film layer, preferably an opaque layer.

In preferred ments of the present invention, the films used are preferably clear or substantially clear, dye-receptive films laminated over , or substantially opaque, substrates. In such ments the substrate is ably white.

The y of a white film can be reduced to a pigment to polymer ratio that allows the dye images to be successfully rendered directly into the white films. No clear layer, to support dye cs, becomes necessary. Preferably, the opacity is suitable to render dye images on a thermoplastic film, and preferably provides about a m of 5%, 8%, 10% or 15% light transmission. In some embodiments, a film comprising titanium dioxide and a polycarbonate can be used to create the appropriate level of light transmission suitable for the dye .

In order to achieve the desired opacity of the film, the ratio of polymer to pigment will vary ing on the thickness of the film gauge. For e, a thinner gauge film will require more pigment, while a film with a thicker gauge will e less pigment to achieve the desired opacity. Thus, the rzpigment ratio can be e.g., from 1:20 to 20:1, 1:15 to 15:1; 1:10 to 10:1, 1:5 to 5:1, depending on the film gauge.

In certain embodiments of the present invention, the substrate can be coated with a material suitable for use in injection molding. For example, coatings such as water—based, solvent-based or UV cured coatings, can be placed over opaque, or substantially opaque, substrates. In such embodiments, any type of coating known in the art that can be applied to injection mold films to achieve hardness and chemical resistance can be used.

PCT/U82012/028244 In preferred embodiments, the coatings are placed over the substrate at about 0.001” in ess, or less than about 0.001” in thickness.

The graphic is created using dye s that saturate color into the films rather than traditional surface printed, pigment-based, high temperature ink systems. As the ink is saturated into the film as opposed to resting on the surface, the decorated films produced by this invention without can be easily thermoformed to m to the mold in which they will be inserted, damaging the graphic. The dye images are intimate with the polymer structure of the films and therefore flow with the resins when formed rather than hing and ing like surface printed films. Films produced using the t invention, can be thermofonned over complex loss of color or curves and deep draws (inches), before insertion in the injection mold, t distortion of the graphic. No changes in gate design or molding technique are required to achieve a final decorated product using the methods ofthe present invention.

In the saturation process, the ink is saturated into the films to a depth of from about .0001” to about 0.01”, and preferably to a depth of about .004”. Preferably, the ink is saturated into the film by sublimation.

In embodiments wherein the substrate comprises both a transparent and an opaque layer, the graphic is preferably printed into the transparent layer.

After the c is printed into the film, the film can be pre-formed using heat and and thereby ing pressure and then placed in injection molds for product molding decorated surfaces without impacting the quality of the graphics. The thermoplastic composition which is shot into the injection molds forms a miscible and/or adhesive bond with the surface of the substrate not directly touching the inside of the mold.

The decorated thermoplastic films of the present invention can be d to any article made by injection molding, such as, e.g., wireless device covers (cell phone covers, etc.), computer cases, car interiors (dashboards, trim, etc.), plastic ware (bowls, utensils, etc.), and the like.

The following examples are set forth to assist in understanding the invention and should not be construed as specifically limiting the invention described and claimed herein. Such variations of the invention, including the substitution of all equivalents now known or later developed, which would be within the w of those skilled in the art, and changes in W0 2012/122360 PCT/U82012/028244 formulation or minor changes in experimental graphic, are to be considered to fall within the scope of the invention incorporated herein. {0041] A decorated thermoplastic film was made by: (i) rendering a dye—based ink graphic on a surface of transfer paper; (ii) transferring the graphic by dye dispersion into a laminate substrate; (iii) placing the decorated ate in a mold, with the c being in contact with the inside wall of the mold; and (iv) injecting a thermoplastic composition into the mold.

A decorated thermoplastic film was made by: (i) printing a sed ink a graphic on a surface oftransfer paper; (ii) transferring the graphic by dye dispersion into the top layer of a laminate substrate made ofthermoplastic resins; (iii) forming the decorated substrate to attain a three-dimensional decorated substrate; (iv) g the decorated substrate in a mold, with the top layer ofthe laminate substrate with the graphic in contact with the inside wall of the mold; and (iv) injecting a thermoplastic composition into the mold.

Example 3 A decorated thermoplastic film was made by: (i) printing a dye—based inkjet ink a graphic on a e of transfer paper; (ii) transferring the graphic by sublimation into the surface of a multiple laminate substrate comprising a ntially opaque layer and a substantially transparent layer, where the graphic was transferred into the substantially transparent layer; (iii) placing the decorated substrate in a mold, with the graphic surface layer in contact with the inside wall of the mold; and (iv) injecting a thermoplastic composition into the mold.

W0 2012/122360 PCT/U82012/028244 Example 4 A decorated thermoplastic film was made by: (i) printing a dye-based inkjet ink a graphic on a surface of transfer paper; (ii) erring the graphic by sublimation into the e of a multiple laminate substrate comprising a layer of substantially opaque polycarbonate homopolymer and a layer of transparent film, the multi-ply made up of one ply of opaque polycarbonate homopolymer, the transparent layer; one ply of transparent polymer, where the graphic was transferred into (iii) placing the decorated substrate in a mold, with the decorated surface of the ate in t with the inside wall of the mold; and (iv) injecting a thermoplastic composition into the mold to form an film such that a strong miscible bond developed between the opaque undecorated second surface of the decorated ate and the thermoplastic composition.

Example 5 A decorated thermoplastic film was made by: (i) printing a dye—based inkjet ink graphic on a surface of transfer paper; (ii) transferring the c by sublimation into the first surface of a multiple te substrate, wherein the first surface comprised a layer of polyvinyl fluoride (PVF) and a polycarbonate; (iii) placing the decorated substrate in a mold, with the decorated first surface ofthe substrate in contact with the inside wall of the mold; and (iv) injecting a thermoplastic composition into the mold to form an film such that a strong miscible bond developed between the opaque undecorated second surface of the decorated substrate and the thermoplastic composition.

Example 6 A decorated thermoplastic film was made by: (i) printing a dye-based inkjet ink graphic on a surface of transfer paper; (ii) transferring the graphic by dye sion into a surface of a transparent film; PCT/U82012/028244 (iii) laminating the d transparent film to another piece of substantially opaque white film, with the printed surface in contact with the film in lamination; wherein a miscible bond formed n the transparent printed surface and the white multiply film laminate. (v) placing the decorated multi-ply laminate in a mold with the transparent film touching the inside wall of the mold and the white film facing the mold ; and (vi) injecting a thermoplastic composition into the mold to form an film such that a strong miscible bond developed between the opaque undecorated second surface ofthe decorated ate and the thermoplastic composition.

Example 7 (Prophetic) A decorated thermoplastic film can be made by: (i) printing a dye-based ink a graphic directly into the surface of the substrate; (ii) placing the decorated substrate in a mold, with the top layer of the laminate substrate with the c in contact with the inside wall of the mold; and (iii) curing the film using heat and pressure. 1001024141 - 5 MR 2015

Claims (30)

What is Claimed:
1. l. A decorated thermoplastic film comprising: (i) a substrate having a first surface and a second surface located opposite the first surface, the substrate having a graphic saturated into the first e and the first surface sing a film layer comprising polyvinyl fluoride (PVF); and (ii) a thermoplastic composition in contact with the second surface of the substrate, wherein the thermoplastic composition does not t the first surface of the ate.
2. 2. The decorated thermoplastic film of claim 1, wherein the thermoplastic composition, under heat and pressure, forms a miscible and/or adhesive bond with the second surface of the 10 substrate.
3. 3. The decorated thermoplastic film of claim 2, wherein the substrate comprises multiple film layers.
4. 4. The decorated thermoplastic film of claim 3, wherein the multiple film layers comprise transparent layers, opaque layers, or a combination thereof. 15
5. 5. The decorated thermoplastic film of claim 4, wherein the first surface of the substrate comprises a arent layer and the second surface of the substrate comprises an opaque layer.
6. 6. The decorated plastic film of any one of the preceding claims, wherein the substrate comprises a thermoplastic resin suitable for injection molding.
7. 7. The ted thermoplastic film of claim 6, wherein the thermoplastic resin is a 20 polycarbonate homopolymer, carbonate, acrylonitrile-butadiene-styrene resin (ABS), styrene/acrylonitrile (SAN), polyamide, thermoplastic polyurethane, polymethylmethacrylate (PMMA Acrylic), thermoplastic urethane (TPU), Thermoplastic Elastomer (TPE), polyvinyl fluoride (PVF), poly Vinylidine fluoride (PVDF), a blend of rbonate or a mixture thereof.
8. 8. The decorated thermoplastic film of claim 6, wherein the thermoplastic resin is a 25 polycarbonate resin.
9. 9. The decorated thermoplastic film of claim 7, wherein the thermoplastic resin is poly Vinyl fluoride (PVF). l001024l4l 2 5 MAR 2015
10. 10. The ted thermoplastic film of any one of the preceding claims, wherein the laminate substrate comprises polycarbonate resin.
11. 11. The decorated thermoplastic film of any one of the ing claims, wherein the graphic comprises a digital inkjet—printed graphic.
12. 12. The decorated thermoplastic film of any one of the preceding claims, wherein the substrate has a coating.
13. 13. A method for making a decorated thermoplastic film comprising: (i) ing a graphic into a substrate, the substrate having a first surface and a second surface located te of the first surface, wherein the graphic is rendered into the first 10 surface of the substrate and the first surface further comprises a film layer comprising polyvinyl fluoride (PVF); (ii) placing the substrate in a mold, wherein the first surface of the substrate is positioned to be in contact with the mold; and (iii) injecting a plastic composition into the mold onto the second surface. 15
14. 14. The method of claim 13, wherein the thermoplastic composition forms a miscible and/or adhesive bond with the second surface of the substrate.
15. 15. The method of claim 13 or 14, wherein the substrate comprises multiple film layers.
16. 16. The method of claim 14, wherein the multiple film layers comprise transparent , opaque layers, or a combination thereof. 20
17. 17. The method of claim 16, wherein the first e of the substrate comprises a transparent layer and the second surface of the substrate comprises an opaque layer.
18. 18. The method of any one of claims 13 to 17, wherein the ate comprises a thermoplastic resin le for injection molding.
19. 19. The method of claim 18, wherein the thermoplastic resin is a polycarbonate 25 homopolymer, copolycarbonate, acrylonitrile-butadiene—styrene resin (ABS), styrene/acrylonitrile (SAN), polyamide, thermoplastic polyurethane, polymethylmethacrylate (PMMA Acrylic), thermoplastic urethane (TPU), Thermoplastic Elastomer (TPE), polyvinyl e (PVF), poly vinylidine fluoride , a blend of rbonate or a mixture thereof. 1001024141 - 5 MAR 21115
20. 20. The method of claim 18, wherein the thermoplastic resin is a polycarbonate resin.
21. 21. The method of claim 18, wherein the thermoplastic resin is poly vinyl fluoride (PVF).
22. 22. The method of any one of claims 13 to 21, wherein the substrate comprises polycarbonate resin.
23. 23. The method of any one of claims 13 to 22, wherein the c is rendered Via digital ink-jet printing.
24. 24. The method of any one of claims 13 to 23, wherein the substrate comprises a coating.
25. 25. The method of any one of claims 13 to 24, wherein rendering the graphic into the substrate comprises: 10 (i) printing the graphic onto a surface of transfer paper; and (ii) transferring the c by sublimation into a side of the substrate.
26. 26. The method of claim 25, wherein the graphic is transferred into a top layer of the substrate comprising thermoplastic resin, and further wherein the substrate with the graphic is formed to attain a three—dimensional substrate. 15
27. 27. The method of claim 25, wherein the substrate comprises a le laminate substrate sing a substantially opaque layer and a ntially transparent layer, and further n the graphic is transferred into the substantially transparent layer.
28. 28. The method of claim 27, wherein the substantially opaque layer comprises polycarbonate homopolymer, plastic polyurethane or copolycarbonate. 20
29. 29. The method of claim 27, wherein a first surface of the multiple laminate substrate comprises a layer of polyvinyl fluoride (PVF), and a second surface opposite the first surface comprises thermoplastic polyurethane.
30. 30. A decorated thermoplastic film produced by the method of any one of claims 13-29.