阅读说明：本技术 高密度柱阵列 (High density pillar array ) 是由 萨拉·E·黑默尔 居伊·M·卡尔曼 于 2019-07-15 设计创作，主要内容包括：本发明提供了一种膜基制品,该膜基制品包括：膜层,该膜层具有第一主侧面和第二主侧面；粘合剂层,该粘合剂层包括与膜的第二主侧面相邻的第一表面和与第一表面相反的第二表面,其中粘合剂层的第二表面包括结构化表面,该结构化表面包括多个向外延伸的突出部,各个突出部具有基部,其中多个突出部的基部占粘合剂层的第二表面的总表面积的至少大约6％；以及油墨层,该油墨层以至少100％的油墨沉积施加到膜层的第一主侧面。(The present invention provides a film-based article comprising: a film layer having a first major side and a second major side; an adhesive layer comprising a first surface adjacent to the second major side of the film and a second surface opposite the first surface, wherein the second surface of the adhesive layer comprises a structured surface comprising a plurality of outwardly extending protrusions, each protrusion having a base, wherein the bases of the plurality of protrusions comprise at least about 6% of the total surface area of the second surface of the adhesive layer; and an ink layer applied to the first major side of the film layer at an ink deposition of at least 100%.)

1. A film-based article comprising:

a film layer having a first major side and a second major side;

an adhesive layer comprising a first surface adjacent to the second major side of the film and a second surface opposite the first surface, wherein the second surface of the adhesive layer comprises a structured surface comprising a plurality of outwardly extending protrusions, each protrusion having a base, wherein the bases of the plurality of protrusions comprise at least about 6% of the total surface area of the second surface of the adhesive layer; and

an ink layer applied to the first major side of the film layer at an ink deposition of at least 100%.

2. The film-based article of claim 1, wherein the ink layer comprises a solvent-based ink.

3. The film-based article of claim 1, wherein the ink layer applied to the first major side of the film layer is comprised of at least two different pigments.

4. The film-based article of claim 1, wherein the film layer is at least one of: optically clear, transparent, translucent, opaque and colored.

5. The film-based article of claim 1, wherein the film layer comprises at least one of: vinyl resins, polyvinyl chloride, plasticized polyvinyl chloride, Polyurethane (PU), polyethylene, polypropylene, fluorine resins, polyethylene terephthalate (PET), glycol-modified polyethylene terephthalate (PETG), polymethyl methacrylate (PMMA), Polycarbonate (PC), and Acrylonitrile Butadiene Styrene (ABS).

6. The film-based article of claim 1, wherein the film layer comprises a plurality of material layers.

7. The film-based article of claim 6, wherein at least one material layer of the plurality of material layers comprises a primer material.

8. The film-based article of claim 1, further comprising a laminating layer adjacent to the outer surface of the ink layer.

9. The film-based article of claim 1, wherein the bases of the plurality of protrusions comprise from about 9% to about 25% of the total surface area of the second surface of the adhesive layer.

10. The film-based article of claim 1, wherein the second surface of the adhesive layer further comprises at least one channel.

11. The film-based article of claim 10, wherein the at least one channel comprises an array of channels.

12. The film-based article of claim 10, wherein the at least one channel comprises an irregular array of channels.

13. A film-based article comprising:

a film layer having a first major side and a second major side;

an adhesive layer comprising a first surface adjacent to the second major side of the film and a second surface opposite the first surface, wherein the second surface of the adhesive layer comprises a structured surface comprising:

a plurality of outwardly extending protrusions, each protrusion having a base, wherein the bases of the plurality of protrusions comprise at least about 6% of a total surface area of the second surface of the adhesive layer; and

an array of channels; and

a solvent-based ink coating applied to the first major side of the film layer.

14. A method of applying a film-based article to a substrate, the method comprising the steps of:

positioning a film-based article adjacent to an outer surface of a substrate, wherein the film-based article comprises:

a film layer having a first major side and a second major side;

an adhesive layer comprising a first surface adjacent to the second major side of the film and a second surface opposite the first surface, wherein the second surface of the adhesive layer comprises a structured surface comprising a plurality of outwardly extending protrusions, each protrusion having a base, wherein the bases of the plurality of protrusions comprise at least about 6% of the total surface area of the second surface of the adhesive layer;

a release liner adjacent the second surface of the adhesive layer; and

an ink layer applied to the first major side of the film layer at an ink deposition of at least 100%;

removing the release liner from the second surface of the adhesive layer; and

applying the second surface of the adhesive layer to the outer surface of the substrate.

Technical Field

The present disclosure relates generally to adhesive materials having positionable and repositionable bonding characteristics, and more particularly to adhesive materials having an array of structured adhesive surfaces.

Background

Pressure Sensitive Adhesive (PSA) films are commonly applied to a wide variety of substrates for decorative, protective, or other purposes involving changes in the aesthetic or functional properties of the underlying substrate. While it is relatively easy to place small pieces of PSA film material on such substrates, it is much more difficult to accurately position larger PSA film materials, such as in the case of automotive wrap or fleet graphic installations.

To facilitate the placement of larger sized PSA films, it is known to use liquids such as water, detergents and/or surfactants or lubricants between the PSA layer of the film and the substrate to which it is to be applied. While effective in some cases, this process is prone to a number of drawbacks, including difficulty in removing enough liquid to allow proper adhesion of the film and inadvertent damage to surrounding materials caused by excess liquid.

Modifying the exposed adhesive surface of certain PSA materials is another method for allowing repositioning relative to an underlying substrate. For example, a discontinuous coating of non-adhesive material extending beyond the PSA layer may prevent the PSA from initially adhering to the substrate; however, the actual adhesion of the adhesive to the substrate is also blocked by the non-PSA extensions. Other surface modifications to films having non-adhesive portions have also been used, resulting in repositionability during equilibrium placement with similar difficulties in final adhesion of the film material.

Other adhesive materials may have a topologically structured adhesive surface, such as adhesive tacks provided by graphic film material commercially available under the trade designation "Controltac" from 3M Company of st paul, Minnesota. Such materials are effective for many applications; however, there is a continuing need to provide structured pressure sensitive adhesive patterns that can be used in certain applications (such as automotive wraps and fleet graphic installations) that achieve desirable slip characteristics to facilitate installation while maintaining chemical properties and mitigating the effects of solvent migration that can occur in some structured adhesive patterns.

Disclosure of Invention

Provided herein are film materials having a structured adhesive surface that includes extended posts and/or recessed channels on one side of the film layer to provide a material that can be easily repositioned during application and securely and/or permanently attached to a substrate once positioned in its desired location. This is even achieved by depositing the printed film with an ink using a solvent ink. The array of pillars may be relatively dense, which reduces the amount of initial tack due to less area of exposed adhesive contacting the substrate. With such a dense array of pillars, the bulk chemistry of the adhesive remains unchanged and continues to build over time as with or without the pillar features. According to embodiments described herein, there can be a controlled reduction in initial tack while maintaining the same adhesion build-up over time.

Furthermore, by varying the geometry and density of the pillars, the slidability performance can be manipulated and controlled. The slip of the pattern was evaluated when the adhesive was first applied to the substrate. The slip properties allow the graphic to freely slip around the substrate, at least to some extent, before actually being applied and adhered to the substrate. In some cases, beads are incorporated into the posts to achieve greater sliding by making fewer contact points with a flat adhesive available. Also, by having a relatively dense array pattern of pillars, the pillars create a more rigid structure in the adhesive, which allows for increased slippage. This behavior was further confirmed when the solvent was printed on the graphic film. In some cases, solvent printing can result in reduced sliding performance due to its interaction with the adhesive. The relatively dense pillar array pattern provided herein helps to mitigate the reduction in slip performance due to its stiffness when printed, and further shows improved slip.

It has also been found that repositionability allows for the graphic film described herein to be applied and then lifted and repositioned on a substrate. In conventional repositionable graphic films, a change in repositionability is achieved upon changing the bulk modulus of the adhesive chemistry. However, with the denser pillar array pattern provided herein, repositionability can be altered and further improved without altering the adhesive chemistry. A denser array of posts allows for easier repositioning of the material due to their increased stiffness, slidability, and lower initial tack. In addition, the relatively dense array of posts can provide a more desirable level of "bite" of the graphic film after adhering to the substrate, which occurs when an installer lifts the material relatively quickly after a large area is applied to the substrate.

Embodiments of the film-based article, according to the film materials described herein, include: a film layer having a first major side and a second major side; an adhesive layer comprising a first surface adjacent to the second major side of the film and a second surface opposite the first surface, wherein the second surface of the adhesive layer comprises a structured surface comprising a plurality of outwardly extending protrusions, each protrusion having a base, wherein the bases of the plurality of protrusions comprise at least about 6% of the total surface area of the second surface of the adhesive layer; and an ink layer applied to the first major side of the film layer at an ink deposition of at least 100%.

The ink layer of the film-based article can comprise a solvent-based ink, and the ink layer can be applied to the first major side of the film layer at an ink deposition of at least 150%, or at least 200%, or at least 250%. The ink layer may be composed of at least two different pigments or at least three different pigments or at least four different pigments.

The film layer may be at least one of: optically clear, transparent, translucent, opaque and colored. The film layer comprises at least one of: vinyl resins, polyvinyl chloride, plasticized polyvinyl chloride, Polyurethane (PU), polyethylene, polypropylene, fluorine resins, polyethylene terephthalate (PET), glycol-modified polyethylene terephthalate (PETG), polymethyl methacrylate (PMMA), Polycarbonate (PC), and Acrylonitrile Butadiene Styrene (ABS). The film layer may include one or more material layers, wherein at least one material layer of the plurality of material layers may be a primer material. The film-based article can include a overlaminate layer adjacent an outer surface of the ink layer.

According to the film material described herein, the bases of the plurality of protrusions of embodiments comprise from about 9% to about 25% of the total surface area of the second surface of the adhesive layer. According to the film material described herein, the bases of the plurality of protrusions of embodiments comprise from about 16% to about 20% of the total surface area of the second surface of the adhesive layer.

According to the film materials described herein, the second surface of the adhesive layer of embodiments further comprises at least one channel, and the at least one channel may comprise an array of channels, which may be irregular.

In accordance with the film material described herein, the plurality of protrusions of an embodiment comprise at least one protrusion having a height that is the same as the height of at least one additional protrusion, and/or at least one protrusion having a height that is different from the height of at least one additional protrusion.

Embodiments of the film-based article, according to the film materials described herein, include: a film layer having a first major side and a second major side; an adhesive layer comprising a first surface adjacent to the second major side of the film and a second surface opposite the first surface, wherein the second surface of the adhesive layer comprises a structured surface comprising a plurality of outwardly extending protrusions, each protrusion having a base, wherein the bases of the plurality of protrusions comprise at least about 6% of the total surface area of the second surface of the adhesive layer; and a solvent-based ink coating applied to the first major side of the film layer.

The film-based articles of the present invention may be applied to a substrate using a method comprising the steps of: positioning a film-based article adjacent to the outer surface of the substrate, wherein the film-based article comprises: a film layer having a first major side and a second major side; an adhesive layer comprising a first surface adjacent to the second major side of the film and a second surface opposite the first surface, wherein the second surface of the adhesive layer comprises a structured surface comprising a plurality of outwardly extending protrusions, each protrusion having a base, wherein the bases of the plurality of protrusions comprise at least about 6% of the total surface area of the second surface of the adhesive layer; a release liner adjacent a second surface of the adhesive layer, the release liner adjacent the second surface of the adhesive layer; and an ink layer applied to the first major side of the film layer at an ink deposition of at least 100%; removing the release liner from the second surface of the adhesive layer; and applying the second surface of the adhesive layer to the outer surface of the substrate.

Drawings

The invention will be further explained with reference to the accompanying drawings, in which:

FIG. 1 is a cross-sectional side view of one embodiment of a film-based article showing an exemplary structured surface comprising a plurality of protrusions and one channel; and is

FIG. 2 is a profile view of one embodiment of a structured pressure sensitive adhesive layer including an array of adhesive pillars.

Detailed Description

According to embodiments described herein, structured Pressure Sensitive Adhesive (PSA) patterns for film materials, such as vinyl, are provided that can be used to apply the film materials in the form of, for example, automotive wraps and fleet graphic installations. Film materials having such structured PSA patterns are able to achieve the desired slip characteristics for ease of installation while maintaining chemical properties and mitigating the effects of solvent migration that may occur in some printed structured adhesive patterns. Exemplary uses of the film-based articles described herein include vehicle wraps, medical tapes, graphic materials for signage, structural tapes, and/or tapes for industrial and/or commercial applications, among others. The dimensions of the film-based article may vary and may be applied to all or only a portion of a particular substrate.

The film-based articles described herein include a film-based article printed with a solvent-based ink and have at least one topologically structured adhesive surface and a backing. The structured adhesive surface allows the sheet to initially adhere weakly to or to a substrate, allowing for relatively easy repositioning as desired, while also allowing for a permanently strong bond to the substrate by compressing the projections until the underlying base adhesive surface contacts the substrate to which it is to be applied. The structured adhesive surface includes a distribution of adhesive protrusions that project or extend outwardly from the adhesive surface. When it is desired to adhere the article to a substrate, the tab will be exposed by removing the liner sheet or layer. The tab may comprise the same adhesive material as the underlying adhesive layer. In some cases, the protrusions may comprise a different adhesive material than the underlying adhesive layer. In some cases, the projections may contain non-adhesive materials, such as particles or beads, that provide a non-tacky or non-adhesive surface to initially contact the substrate to which the film is applied, allowing the film to "slide" on the surface.

The protrusions may be distributed and arranged to account for about 9% and about 25%, or more preferably about 16% and about 20%, of the total adhesive area at their bases. To achieve these percentages, the approximate areas of all bases of the protrusions in the representative region are added together and compared to the overall dimensions of the representative region. The protrusions may have an average height of, for example, about 8 to 30 microns.

Referring now to the drawings, and initially to FIG. 1, there is shown an exemplary embodiment of a film material or film-based article 10 generally comprising: a film layer 12 having a first side 14 and a second side 16; an adhesive layer 20 having a first side 22 and an opposite second side 24, the first side being adjacent to and bonded to the second side 16 of the film layer 12; a release liner 30 having a first side 32 releasably attached to the second side 24 of the adhesive layer 20 and a second side 34; an ink layer 46 adjacent to the film layer 12; and a coating layer 50 adjacent to ink layer 46. The adhesive layer 20 is a pressure sensitive adhesive that includes a plurality of protrusions 26 and at least one optional channel 27. The release liner 30 includes channels or recesses into its first side 32 that are used to form corresponding protrusions 26 extending from the adhesive layer 20. The release liner 30 also includes projections from its first side 32 that are used to form corresponding channels 27 in the adhesive layer 20. The release liner 30 also serves to protect the underlying adhesive layer 20 and its corresponding protrusions 26 at any time prior to application of the film-based article 10 to a substrate. The release liner 30 can be partially or completely removed from the adhesive layer 20 prior to application of the article 10 to a substrate.

Film layer 12 may be conformable or non-conformable, but is preferably a conformable or compliant film material having an elongation level of at least 50% and comprising one or more layers. As used herein, the term "conformable" generally refers to a film that may substantially or completely assume the shape of a three-dimensional substrate comprising convex features, concave features, and/or other shapes or contours. However, determination of the conformability of the film is not limited to the actual application of the film to such substrates, but also includes the case where the film has such capability prior to application to the substrate. In some embodiments, it is possible to assume such shapes without causing undesirable changes to the structural integrity and/or aesthetic appearance of the film. In this sense, conformable films are distinguishable from non-conformable films that may be capable of being applied to a flat surface and/or slightly curved around a surface having a sufficiently large radius of curvature (such as a large cylinder), but may not be capable of being applied to (and conforming to) a more complex three-dimensional substrate.

Factors that may affect the conformability of the film include the type of material used to make the film, the molecular weight of such material, the conditions to which such film is subjected (e.g., temperature, radiation exposure, and humidity), and the presence of additives in the film material (e.g., plasticizer content, reinforcing fibers, pigments, stabilizers (e.g., UV stabilizers), and hardness-enhancing particles).

The film layer 12 utilized in the embodiments described herein is typically made from a variety of plastic materials used by those skilled in the art. Suitable film layers include, for example, film layers that provide some optical property to the finished construction, such as reflected or transmitted color, opacity, retroreflectivity, transparency, scattering, print acceptance, printed images, and patterns. Chemicals for film layers in the 25 μm to 300 μm range may include plasticized PVC film layers (both cast and calendered), urethanes, cellulose, acrylics, olefins, polyesters, and blends thereof. The film layer may be primed with a suitable primer, such as a nitrogen-rich polymer, e.g., an acrylic copolymer, polyamide, or urethane. The primer may or may not be crosslinked via a suitable chemical such as epoxy, melamine, or isocyanate. The film layer thickness may vary widely depending on the desired application, but is typically in the range of about 300 μm or less and preferably about 25 μm to about 100 μm. The film layer may be optically clear or transparent so that light can pass through it and objects behind the layer can be clearly seen; may be translucent such that light (but not the detail image) is transmitted through it (i.e., translucent); may be opaque such that it cannot be seen through (i.e., opaque); and/or colored over its entire area.

A specific example of a suitable film layer is a plasticized polyvinyl chloride film and has sufficient inelastic deformation after stretching that the film does not recover to its original length when stretched. Preferably, the film layer has an inelastic deformation of at least 5% once it has been stretched to 115% of its original length. Typical formulations for vinyl films include polyvinyl chloride resin, light and/or heat stabilizers, plasticizers, and optionally pigments. The amount of plasticizer may be less than about 40 weight percent and is preferably comprised of a non-migratable polymeric plasticizer that is compatible with the ethylene film and provides the desired flexibility and durability. One suitable plasticizer is a combination of a polymeric polyester elastomer and an ethylene vinyl acetate copolymer, such as Elvaloy742, manufactured by DuPont Co, which are soluble in aromatic solvents and are present in amounts of about 26 parts and 10 parts, respectively, per 100 parts of vinyl resin.

Non-limiting examples of film layers that can be used in the present invention can be thin or thick plastics (synthetic or natural), reflective sheets, fabrics (woven or non-woven), paper, metal foils, composite release liners, and the like. The film layer can be configured such that the resulting article is a graphic article, transfer tape, double-sided tape, awning, and the like. In addition, the film layer may include additional functional and decorative layers such as clear coats, decorative graphics, dust and weather resistant coatings, adhesive layers known in the art, screen printable inks, barrier layers, adhesion promoters, multilayer translucent films, and the like. Such functional layers and decorative layers are known in the art and may be used, applied or laminated according to techniques known to those skilled in the art.

One or more primer layers may optionally be used to enhance the bond between the film layer and the adhesive layer. The type of primer will vary with the type of film and adhesive used, and one skilled in the art can select an appropriate primer. Examples of suitable primer layers include chlorinated polyolefins, polyamides, and modified polymers disclosed in U.S. patents 5,677,376, 5,623,010 and those disclosed in WO 98/15601 and WO 99/03907, as well as other modified acrylic polymers. Typically, the primer is dispersed in sufficient solvent at very low concentrations, e.g., less than about 5% solids, and applied to the film and dried at room or elevated temperature to form a very thin layer. Typical solvents used may include water, heptane, toluene, acetone, ethyl acetate, isopropanol, and the like, used alone or as a blend thereof.

According to embodiments of the film article, the pressure sensitive adhesive layer may comprise adhesives, such as those capable of retaining protrusions extending from the exposed surface after formation with a molding tool, backing, or liner, or after coating on a molding tool, backing, or liner from which it is subsequently removed. The particular pressure sensitive adhesive selected for a given application depends on the type of substrate to which the article will be applied and the method used to produce the adhesive-backed article. In addition, useful structured pressure sensitive adhesives should be able to retain their structured surface long enough to allow for the use of adhesive backed articles.

Pressure sensitive adhesives are adhesives that are in dry form (substantially free of solvent other than residual solvent) and in some cases are permanently tacky at room temperature (e.g., about 15 ℃ to about 25 ℃) and can be securely adhered to a variety of different surfaces with only contact, without the need for further manual pressure. The adhesive does not need to be activated by water, solvents or heat to exert strong adhesive holding power on materials such as paper, cellophane, glass, plastic, wood, painted surfaces, and metal. The pressure-sensitive adhesive is generally chemically composed of a rubber resin material, an acrylic resin, a urethane resin, a silicone resin, or the like. Non-pressure sensitive adhesives, heat activated or solvent activated adhesives may be used if they can exhibit certain elastic elongation properties.

Many types of pressure sensitive adhesives may be used for the film-based article 10. The adhesive used may be selected based on the type of substrate to which it is to be adhered. Classes of pressure sensitive adhesives include acrylics, tackified rubbers, tackified synthetic rubbers, ethylene vinyl acetate, silicones, and the like. Suitable acrylic adhesives are disclosed in, for example, U.S. Pat. nos. 3,239,478, 3,935,338, 5,169,727, U.S. Pat. No. RE24,906, U.S. Pat. nos. 4,952,650 and 4,181,752. Preferred classes of pressure sensitive adhesives are the reaction products of at least an alkyl acrylate and at least one reinforcing comonomer. Suitable alkyl acrylates are those having a homopolymer glass transition temperature of less than about-10 ℃ and include, for example, n-butyl acrylate, 2-ethylhexyl acrylate, isooctyl acrylate, isononyl acrylate, octadecyl acrylate, and the like. Suitable reinforcing monomers are those having a homopolymer glass transition temperature of about-10 ℃ and include, for example, acrylic acid, itaconic acid, isobornyl acrylate, N-dimethylacrylamide, N-vinyl caprolactam, N-vinyl pyrrolidone, and the like.

The adhesive layer may comprise a polymer dispersed in a solvent or water, and coated onto a release liner and dried, and optionally crosslinked. The drying process may include one or more of air drying, oven drying, and UV curing, depending on the material. If solvent-based or aqueous pressure sensitive adhesive compositions are employed, the adhesive layer typically undergoes a drying step to remove all or most of the carrier liquid. The additional coating step may help to achieve a smooth surface. The adhesive may also be hot melt coated on a liner or structured backing. Alternatively, the monomeric pre-adhesive composition may be coated onto a liner and polymerized with an energy source such as heat, UV radiation, electron beam radiation.

Where a relatively thick coating of pressure sensitive adhesive is desired, it may be desirable to apply a multilayer adhesive or an in situ photopolymerized adhesive. For example, a mixture of the monomers alkyl acrylate, copolymerizable monomer (such as acrylic acid), and optional polymer may be copolymerized by exposure to ultraviolet radiation to have reached a pressure sensitive adhesive state.

In an exemplary manufacture of the film-based article 10, the adhesive layer 20 is applied to the liner 30 such that the adhesive mixture flows into recesses in the liner surface corresponding to the protrusions 26 to be formed. The film layer 12 is then laminated to the adhesive layer 20. While the film layer 12 is shown as a single ply, it may alternatively be formed of multiple plies or layers of thermoplastic material, additional adhesive layers, primer layers, protective coatings, barrier layers, and any other structure and combination of structures known to those skilled in the art, such as signage sheets, transfer or release liners, transfer tapes, adhesive coated film foams, woven and nonwoven sheets, paper, and metal foil.

Referring also to fig. 2, an embodiment of an adhesive layer of an adhesive film backing or layer is shown. As shown, the plurality of protrusions 26 are relatively evenly distributed on the functional portion of the adhesive layer surface 20, but in some cases, the protrusions 26 are arranged in a pattern that includes more or less dense areas, random distribution, or the like. The shape of the projections 26 may be set such that the cross-section of the projections taken parallel to the plane of the adhesive layer may be oval, circular, polygonal, rectangular, star-shaped, annular, irregular, and any combination thereof. The base of these projections 26 is considered to be the portion of the projection directly adjacent to the adhesive layer surface 20.

FIG. 1 shows a protrusion having a relatively flat top; however, the top surface of the protrusion may alternatively be curved, contoured, or irregular, and may include beads that provide the protrusion with a textured type of top surface. In embodiments, the interior angle between the top and sides of the projections 26 is preferably no greater than 150 degrees, and more preferably between 90 and 135 degrees. In embodiments, the size and shape of the protrusions closely match the mold or tool that alters the surface of the pad; however, in other embodiments, the adhesive does not completely fill the recessed area during the forming process, thereby forming a material with protrusions that generally match the shape of the mold or tool, but that also have differences.

The average height of the array of protrusions on the adhesive surface may be at least 12 μm, as measured from the adhesive surface from which the protrusions extend to the point or general area of the protrusions furthest from the adhesive surface. The protrusions typically have a maximum height of 200 μm, preferably 150 μm and more preferably 50 μm. The height may vary, but the height variation is preferably random, as it may be undesirable to have multiple shorter protrusions grouped together. In addition, the average height of the projections 26 is about 15 μm, so height variations are taken into account within a single projection. However, the height and interior angle depend in part on the adhesive composition selected for practicing the invention. While the tab height is preferably uniform, it is contemplated to have a plurality of tabs with manufacturing height variations. It is also contemplated to have a plurality of protrusions having a predetermined height variation to advantageously further control the positionability and/or repositionability.

Generally, the protrusions may be formed by applying an adhesive directly onto the structured liner. For composite protrusions, the protrusions may be formed by applying an adhesive directly onto the structured liner, with the small recesses having been previously filled with beads and optionally a functionally sufficient amount of a polymeric binder. Alternatively, the composite projections may be formed with a first coat of binder/bead slurry followed by a binder-only coat. The second adhesive-only coat may be a chemically different adhesive, provided that the second adhesive is sufficiently compatible with the first coat adhesive. This is generally useful to keep the protrusions on the adhesive (second coating) surface after the liner is removed during application. As shown in fig. 2, the shape of the projections 26 may be rounded or irregular depending on whether a portion of the adhesive or bead remains in the recess in the liner when the liner is removed from the adhesive and/or whether the adhesive coated on the liner completely fills the recess during the filling process.

While the projections described herein may be made entirely of binder, they may alternatively be comprised of a composite of binder and beads, wherein the beads are substantially covered by binder. In some cases, a small portion of the beads may be above or below the surface and not covered by adhesive, provided that the entire surface of the protrusions provides the adhesive surface.

When the film-based articles of the present invention are used for decorative purposes, the beads are preferably substantially less than the thickness of the adhesive layer, such that the beads do not damage the exposed face of the backing after being pressed into the adhesive layer. For example, when the thickness of the adhesive layer is about 20 to 40 μm, the average diameter of each bead is preferably less than 20 μm, the average diameter is preferably 1 to 15 μm, and the average diameter is more preferably 1 to 10 μm. The beads within such a set may be of the same size or a mixture of sizes. Beads smaller than about 0.5 μm may be more difficult and expensive to use than larger particles. In non-decorative applications such as masking tape, the beads may exceed the thickness of the adhesive. Composite protrusions may also be prepared by first coating the impression liner with latex resin to partially fill the depressions, wiping the surface of the liner, and allowing the resin to dry or set. The dried or coagulated resin is then coated with a binder solution.

Generally, the protrusions may be formed by applying an adhesive directly onto the structured liner. For composite protrusions, the protrusions may be formed by applying an adhesive directly onto the structured liner, with the small recesses having been previously filled with beads and optionally a functionally sufficient amount of a polymeric binder. Alternatively, the composite projections may be formed with a first coat of binder/bead slurry followed by a binder-only coat. The second adhesive-only coat may be a chemically different adhesive, provided that the second adhesive is sufficiently compatible with the first coat adhesive. This may be important to keep the protrusions on the adhesive (second coat) surface after the liner is removed from the film-based article during application.

A method for making a film-based article comprising composite protrusions comprises the steps of: (a) preparing a slurry of beads; (b) applying a paste onto the impression liner to fill the depressions in the impression liner; (c) wiping the impression liner to remove excess slurry; (d) coating the filled imprinting pad with an adhesive solution; and (e) allowing the binder solution to adsorb into and around the beads prior to drying. The binder solution may be a latex binder solution or a solution containing reactive monomers.

Preferred liners for the film-based articles of the present invention are low adhesion surface polymeric plastic films. The liner may be a protective liner, a release liner, or the like. When the film base article is manufactured by the first of the above methods, the plastic film may be embossed to form the concave portion. The embossable plastic film may be self-supporting, but a preferred liner is kraft paper having a relatively thin embossable polyethylene coating covered on one or more surfaces by a silicon release coating. Useful self-supporting plastic films include, but are not limited to, plasticized poly (vinyl chloride) and biaxially oriented poly (ethylene terephthalate) and polypropylene, which are both economical and have good strength, toughness and dimensional stability. Preferably, the recess in the impression pad is generally frustoconical in shape with a substantially flat base.

The film-based articles described herein may be provided in a sheet, roll, or other desired configuration. The film may be printed with any number of different types of inks to provide an ink layer 46 of the film-based article 10, such as an exemplary solvent-based ink, which, as will be described below, may be provided, for example, at an ink deposition of at least 45% (i.e., the ink deposition is the percentage of ink on a given area where the ink is made up of solvent-based pigments equal to 45%). The printing may be performed before or after laminating the adhesive layer to the film. Generally, providing a greater number of protrusions can mitigate the effects of solvent migration that affect the slip and tack of the adhesive, where more ink deposition generally makes the adhesive of the film-based article more tacky.

As used herein, the concept of ink deposition in digital printing generally refers to the amount of ink used to produce a certain color. More specifically, there are four primary colors (black, cyan, magenta, and yellow), and the print range for each primary color may be 0-100%. By mixing the primary colors, more than 100% ink deposition can be achieved. The actual volume of ink deposited varies from printer to printer, where ink deposition is a specified color that is converted to machine language and sent to the printer in an image file that is subsequently processed by software. In this conversion process, the colors calculated in the design are then referenced to the printer's color output/blend table, and the color management process will determine the ink laydown to achieve the specified color.

In one embodiment of the film-based articles provided herein, the release liner comprises an exemplary surface depression area coverage of 16% and 28900/in at a density of 170 lines/in (67 lines/cm)²(4480 pieces/cm)²) Of the housing. This produced an array of surface protrusions with a draft angle of 60 degrees in a square grid with a spacing of 390 microns and a height of 13 to 14 microns and a width of 40 microns on the particle-filled side of the release liner.

An overlaminate layer 50 (such as a film commercially available from 3M company, st paul, mn under the trade designation "Scotchcal") may be laminated to the film side of the overlaminate printed structured film to provide embodiments of the film constructions described herein. Generally, the overlaminate layer can be a film that protects the ink layer printed on the vinyl from UV, scratch, and weathering. The overlaminate layer may improve the appearance, performance, and durability of the graphic film.

Embodiments of the film-based article 10 provided herein additionally include channels 27 that allow some venting of air or fluid trapped between the adhesive and the surface of the substrate to which the article 10 is applied. The channels 27 may be considered to be part of a structured surface defining channels with specific characteristics in the pressure sensitive adhesive to allow such evacuation of air or fluid. Thus, the channels in the adhesive of embodiments of the articles provided herein are of particular size and characteristics to improve air/fluid egress including channels or channel segments that do not necessarily terminate at the perimeter of the film article.

Examples

Objects and advantages of this invention are further illustrated by the following examples, but the particular materials and amounts thereof recited in these examples, as well as other conditions and details, should not be construed to unduly limit this invention. These examples are for illustrative purposes only and are not intended to limit the scope of the appended claims.

Films with various post (protrusion) contact areas were prepared and printed at different ink deposition levels. The ability of the sample to slide on the surface was evaluated. All parts, percentages, ratios, etc. in the examples, as well as the remainder of the specification, are by weight unless otherwise indicated. The following abbreviations are used herein: in/min is inch/min; sec is seconds; cm is equal to centimeter; in is inch; lb is pounds; kg is Kg; DEG C is centigrade; RH-relative humidity.

Material

Sliding test

The slip test evaluates the slip of the material on the substrate. The substrate was a precoated 12in x 12in (4.7cm x 4.7cm) aluminum panel from almet SUPPLY (Parsippany, NJ Branch). The aluminum was pre-painted with a white acrylic paint.

Procedure for slide testing

First, the liner is removed from the graphic film to expose the adhesive. Next, the adhesive side of the graphic film is applied to a base plate (placed gently on the plate without pressure). The sample is then moved around the base plate by lifting one end of the material and pulling on the base. The slip rating level is then assigned based on the slip and stickiness of the graphic film (rating levels are as follows). Two separate evaluators were used and the average of the results was recorded for each sample using the following scale:

level 1: non-slip (no slip from side to side on substrate, high tack, film adhesion to substrate)

Level 2: low slip and moderate tack (wrinkles are noted when force is applied to break the adhesion)

Level 3: moderate slip and moderate tack (slight wrinkles noted when force was applied to break the adhesion)

Level 4: moderate slip and low tack (slip after horizontal application of force to break adhesion)

Level 5: maximum slipperiness (free sliding without adhesion to substrate)

Coefficient of friction sliding test

Coefficient of friction sliding test the sliding properties of the materials were evaluated. The test equipment used was I-MASS PEEL TESTER SP-2100(10lb/5kg load cell) from IMASS INC located at Worcester (Accord, MA), Mass.). A7.6 cm by 20.3cm sample was conditioned for 24 hours at 23 deg.C +/-2 deg.C and 50 +/-5% RH. The IMASS slide (201 grams) was wrapped with the liner removed from F2, with the paper side of the liner wrapped inward. An additional 800 grams of weight was added to the slide. The IMASS slide is secured by attaching a tether (fishing line) of the slide to the load cell. The tether length is about 6.5in (16.5 cm).

Procedure for coefficient of friction slip testing

The liner was removed from the film sample, leaving the adhesive exposed. The sample was then placed on the platen with the adhesive side facing up. The leading end of the sample was then glued to the platen. The slide is placed so that its starting position is just before the sample and partly on the tape. The slider was then pulled at a test speed of 300in/min (0.127m/sec) on the adhesive side of the sample and the results were recorded in grams.

Example 1-film printed structured film (E1)

The second pattern was embossed into the release liner (L1) by passing the release liner between a smooth silicone rubber roller and an engraved metal roller. This produced an array of surface protrusions with a draft angle of 60 degrees in a square grid with a spacing of 390 microns and a height of 13 to 14 microns and a width of 40 microns on the particle-filled side of the release liner.

The pressure sensitive adhesive solution (a1) slot film was coated and dried onto the particle-filled side of the embossed release liner using a continuous coater/dryer line. This results in an adhesive coated embossed release liner. The adhesive thickness when dry was 30 microns. The adhesive was dried at 93 ℃ for 54 seconds. The exposed adhesive side of the adhesive coated embossed release liner was laminated to film F1 at room temperature to form a structured adhesive film.

The structured adhesive film was inkjet printed using a Roland SOLJET PRO 4XR-640 high volume printer (Roland DGA Corp., Irvine, CA) with a solvent ink available from Roland corporation as ECO-SOL MAX 2. The printer was set up using 45% ink deposition. Ink deposition consisted of a solvent-based pigment combination equal to 45% ink deposition and was achieved by using 45% black pigment. The films were aged at room temperature for 24 hours. O1 was laminated to the film side of the printed structured adhesive film. This results in a film-printed structured adhesive film. The materials were tested using the sliding test described above. See table 1 for results.

Comparative example 1(CE1)

Comparative example 1 is unprinted film F2. The materials were tested using the above-described sliding test and coefficient of friction sliding test. See tables 1 and 2 for results.

Example 2-laminating printed structured film (E2)

The structured binder film in example 1 was processed the same as example 1 except that the ink was deposited at 100% and consisted of cyan pigment. The materials were tested using the sliding test described above. See table 1 for results.

Example 3 film-printed structured film (E3)

The structured adhesive film of example 1 was processed the same as example 1 except that the ink deposition was 150% and consisted of a solvent content level equal to 150% and consisted of 100% cyan pigment and 50% magenta pigment. The materials were tested using the sliding test described above. See table 1 for results.

Example 4 film-printed structured film (E4)

The structured binder film of example 1 was processed the same as example 1 except that the ink deposition was 200% and consisted of 100% cyan pigment and 100% magenta pigment. The materials were tested using the sliding test described above. See table 1 for results.

Example 5 film-printed structured film (E5)

The structured binder film of example 1 was processed the same as example 1 except that the ink deposition was 250% and consisted of 50% cyan pigment, 50% magenta pigment, 50% yellow pigment, and 100% black pigment. The materials were tested using the sliding test described above. See table 1 for results.

Example 6-film printed structured film (E6)

The second pattern was embossed into the release liner (L2) by passing the release liner between a smooth silicone rubber roller and an engraved metal roller. This produced an array of surface protrusions with a draft angle of 60 degrees in a square grid with a spacing of 390 microns and a height of 13 to 14 microns and a width of 40 microns on the particle-filled side of the release liner.

The pressure sensitive adhesive solution (a1) slot film was coated and dried onto the particle-filled side of the embossed release liner using a continuous coater/dryer line. This results in an adhesive coated embossed release liner. The adhesive thickness when dry was 30 microns. The adhesive was dried at 93 ℃ for 54 seconds. The exposed adhesive side of the adhesive coated embossed release liner was laminated to film F1 at room temperature to form a structured adhesive film.

The structured adhesive film was inkjet printed using a Roland SOLJET PRO 4XR-640 high volume printer (Roland DGA Corp., Irvine, CA) with a solvent ink available from Roland corporation as ECO-SOL MAX 2. The printer was set up using 45% ink deposition. The ink deposit consisted of a solvent content level equal to 45% and consisted of black pigment. The films were aged at room temperature for 24 hours. O1 was laminated to the film side of the printed structured adhesive film. This results in a film-printed structured film. The materials were tested using the sliding test described above. See table 1 for results.

Example 7 film-coated printed structured film (E7)

The structured binder film in example 6 was processed the same as example 6 except that the ink was deposited at 100% and consisted of cyan pigment. The materials were tested using the sliding test described above. See table 1 for results.

Example 8 film-coated printed structured film (E8)

The structured adhesive film of example 6 was processed the same as example 6 except that the ink deposition was 150% and consisted of a solvent content level equal to 150% and consisted of 100% cyan pigment and 50% magenta pigment. The materials were tested using the sliding test described above. See table 1 for results.

Example 9 film-coated printed structured film (E9)

The structured binder film in example 6 was processed the same as example 6 except that the ink deposition was 200% and consisted of 100% cyan pigment and 100% magenta pigment. The materials were tested using the sliding test described above. See table 1 for results.

Example 10 film-printed structured film (E10)

The structured binder film in example 6 was processed the same as example 6 except that the ink deposition was 250% and consisted of 50% cyan pigment, 50% magenta pigment, 50% yellow pigment, and 100% black pigment. The materials were tested using the sliding test described above. See table 1 for results.

Table 1: sliding results of sliding test

Examples	Sliding rating scale (1-5)	Ink deposition (%)
			E1	4.5	45
CE1	4.5	0
			E2	4.0	100
E3	3.5	150
			E4	2.0	200
E5	3.0	250
			E6	5.0	45
E7	4.5	100
			E8	3.5	150
E9	3.5	200
			E10	4.0	250

Example 11 film-printed structured film (E11)

The structured adhesive film from example 1 was inkjet printed with an environmentally friendly solvent Ink obtained from the 3M SX Ink series (OKI Data Corporation, Tokyo, Japan) using an OKI Data colorpaint M-64s printer (OKI Data Corporation, Tokyo, Japan). The printer was set up using 250% ink deposition. Ink laydown consisted of a solvent-based pigment combination equal to 250% ink laydown, and was achieved with a pigment combination of 50% yellow, 50% magenta, 50% cyan, and 100% black. The films were aged at room temperature for 24 hours. O1 was laminated to the film side of the printed structured adhesive film. This results in a film-printed structured film. The materials were tested using the coefficient of friction sliding test described above. See table 2 for results.

Example 12 film-printed structured film (E12)

The structured adhesive film from example 6 was inkjet printed with an environmentally friendly solvent Ink obtained from the 3M SX Ink series (OKI Data Corporation, Tokyo, Japan) using an OKI Data colorpaint M-64s printer (OKI Data Corporation, Tokyo, Japan). The printer was set up using 250% ink deposition. Ink laydown consisted of a solvent-based pigment combination equal to 250% ink laydown, and was achieved with a pigment combination of 50% yellow, 50% magenta, 50% cyan, and 100% black. The films were aged at room temperature for 24 hours. O1 was laminated to the film side of the printed structured adhesive film. This results in a film-printed structured film. The materials were tested using the coefficient of friction sliding test described above. See table 2 for results.

Comparative example 2-overlay printed structured film (CE2)

Structured adhesive film F2 was inkjet printed with an environmentally friendly solvent Ink obtained from the 3M SX Ink series (OKI Data Corporation, Tokyo, Japan) using an OKI Data colorpaint M-64s printer (OKI Data Corporation, Tokyo, Japan). The printer was set up using 250% ink deposition. Ink laydown consisted of a solvent-based pigment combination equal to 250% ink laydown, and was achieved with a pigment combination of 50% yellow, 50% magenta, 50% cyan, and 100% black. The films were aged at room temperature for 24 hours. O1 was laminated to the film side of the printed structured adhesive film. This results in a film-printed structured film. The materials were tested using the coefficient of friction sliding test described above. See table 2 for results:

table 2: sliding results of coefficient of friction sliding test

Examples	Sliding value (gram)	Ink deposition (%)
			E11	176.9	250
E12	143.2	250
			CE1	128.3	0
CE2	486.9	250

The invention has now been described with reference to several embodiments thereof. The entire disclosure of any patent or patent application identified herein is hereby incorporated by reference. The foregoing detailed description and examples have been given for clarity of understanding only. They are not to be construed as unnecessarily limiting. It will be apparent to those skilled in the art that various modifications can be made to the described embodiments without departing from the scope of the invention. Thus, the scope of the present invention should not be limited to the structures described herein, but only by the structures described by the language of the claims and the equivalents of those structures.