Method of patterning adhesive layer

Abstract

The present disclosure generally relates to patterning adhesives for use on rough substrates. More particularly, the present disclosure relates to methods of patterning an adhesive via a roll-to-roll process to facilitate ultra strong adhesion to rough substrates.

Description

Technical Field

[0001] The present disclosure generally relates to patterning adhesives for use on rough substrates. More particularly, the present disclosure relates to methods for patterning adhesives by a roll-to-roll process to facilitate super-strong adhesion to rough substrates. Background Art

[0002] Adhesive laminates are known in the art. Such products are provided in various forms, including for example tapes, sheets, and labels. While satisfactory in many respects, there is a need for new classes of laminates that provide one or more functions and that can be produced in a cost-effective manner.

[0003] Various techniques for applying adhesives to face materials are known. Also known are methods of coating an adhesive on a secondary material and then combining it with a face material. The adhesive layer can be continuous or discontinuous. Discontinuous adhesive layers typically include regular or uniform patterns or structures. While such patterning can reduce the amount of adhesive used, regular or uniform patterns or structures can have limitations, such as unglued / uncoated edges of labels resulting in poor dispensing, sagging, poor printing quality, and / or poor die-cutting. While satisfactory in many respects, there is still a need for additional strategies for depositing adhesives on face materials that can maintain or improve specific properties and / or characteristics of the resulting structure. Summary of the Invention

[0004] Exemplary embodiments relate to a method for patterning an adhesive layer, which includes: providing a backing (liner) having a first side, a second side, a first edge, and a second edge; contacting the first side of the backing with a deformable member to at least temporarily deform the backing by the contact with the deformable member; and while the backing is temporarily deformed, substantially simultaneously applying an adhesive to at least a portion but not the entire first side of the backing in a substantially uniform manner when the backing is at least temporarily deformed, thereby forming a pattern of the adhesive; and the contact of the pattern of the adhesive with a rough substrate enables enhanced adhesion to the rough substrate with less adhesive than a flood coat. This embodiment or another exemplary embodiment may provide that the adhesive is applied in a discontinuous manner. This embodiment or another exemplary embodiment may provide that the adhesive is applied in a continuous manner. This embodiment or another exemplary embodiment may provide that the backing is a paper-derived backing having a moisture content. This embodiment or another exemplary embodiment may provide that, prior to the contact, it further includes: adjusting the moisture content of the backing. This embodiment or another exemplary embodiment may provide that the moisture content is adjusted by adding moisture to the backing. This embodiment or another exemplary embodiment may provide that the moisture content is adjusted by removing moisture from the backing. This embodiment or another exemplary embodiment may provide that the moisture content of the backing is adjusted after applying the adhesive. This embodiment or another exemplary embodiment may provide that the backing includes PET. This embodiment or another exemplary embodiment may provide that at least a portion of the backing is silicated. This embodiment or another exemplary embodiment may provide that the backing is laminated with a facestock material. This embodiment or another exemplary embodiment may provide that the applied adhesive has a peak height in a first direction and a peak width between the first edge and the second edge, and wherein the ratio between the peak height and the width is from about 0.02 to about 0.05. This embodiment or another exemplary embodiment may provide that the average height is in the range of about 20 μm to about 40 μm. This embodiment or another exemplary embodiment may provide that the average width is in the range of 0.4 mm to about 2.0 mm. This embodiment or another exemplary embodiment may provide that the percentage of the first side of the backing covered by the peaks of the adhesive is from about 40% to about 60%. This embodiment or another exemplary embodiment may provide that the adhesive is a pressure-sensitive adhesive applied at a weight of from about 6 gsm to about 20 gsm. This embodiment or another exemplary embodiment may provide that the adhesive is a hot-melt adhesive and is applied at a weight of from about 6 gsm to about 40 gsm. This embodiment or another exemplary embodiment may provide that the adhesion of the adhesive to the rough substrate is about 10% to about 50% higher than in the case of the same coating weight. This embodiment or another exemplary embodiment may provide that the deformable member is a roll having a patterned surface etch.This embodiment or another exemplary embodiment may provide that the deforming member is a roller with a patterned surface attachment. This embodiment or another exemplary embodiment may provide that the deforming step is performed at a pressure of 5 PSI to 150 PSI. BRIEF DESCRIPTION OF THE DRAWINGS

[0005] These and other features, aspects, and advantages will be more fully understood and appreciated by reference to the following more detailed description of the presently preferred exemplary embodiments of the invention in conjunction with the accompanying drawings.

[0006] Figure 1 Side view schematic of an exemplary apparatus for patterning a gasket.

[0007] Figure 2a Side view plan view of an exemplary adhesive pattern in accordance with the present disclosure.

[0008] Figure 2b Additional side view plan view of another exemplary adhesive pattern in accordance with the present disclosure.

[0009] Figure 3 Side view perspective view of an exemplary spherical cap in relation to the present disclosure.

[0010] Figure 4 Side view of an exemplary adhesive structure on a rough substrate according to Example 1.

[0011] Figure 5 Side view of an exemplary adhesive structure according to Example 2.

[0012] Figure 6 Side view of an exemplary adhesive structure according to Example 4.

[0013] Unless otherwise indicated, the illustrations in the above figures are not necessarily drawn to scale.

[0014] DEFINITIONS

[0015] As used herein, "regular pattern" means the uniformity, consistency, and / or balance of the shape, arrangement, and / or pattern orientation variations and the homogeneity of the repetition.

[0016] As used herein, "irregular pattern" means the non-uniformity or imbalance of the shape, arrangement, and / or pattern orientation variations and the heterogeneity of the non-repetition.

[0017] As used herein, "repeating pattern" means that the pattern of the adhesive is regular in terms of shape, arrangement, and / or pattern orientation and the heterogeneity is repetitive.

[0018] As used herein, "discontinuous" means that one or more regions, portions, sites, or spaces of the gasket are not covered by the adhesive.

[0019] As used herein, "continuous" means that the entire surface of a liner is covered by an adhesive at a certain level.

[0020] As used herein, "rough substrate" refers to any substrate having a non-uniform surface level pattern with known irregularities. For example, cardboard and kraft paper are two such substrates that are rough substrates. Roughness can be expressed by different metrics depending on the source. For example, R a is the roughness average or arithmetic mean of the absolute values of the roughness profile. And R z is the average roughness depth as the arithmetic mean of the individual roughness depths.

[0021] As used herein, with respect to an adhesive pattern, the expression "substantially uniform" means that the area of the applied adhesive pattern that is defective is less than 2% relative to the total area of the applied adhesive pattern, and preferably, the area of the applied adhesive pattern that is defective is less than 1% relative to the total area of the applied adhesive pattern.

[0022] As used herein, with respect to an adhesive pattern, the term "defect" means a substantial deformation in the adhesive pattern that is different from the desired shape and results in poor adhesion. For example, if an adhesive is deposited with a standard height and width, any deviation in either direction can be considered a defect.

[0023] As used herein, with respect to a laminate structure, the term "multi-layer" means a face material coated with an adhesive having one or more additional layers. Non-limiting examples of such layers that make up the multi-layer include a protective layer, a spacer layer, an adhesive layer, a layer containing an optical component, a metal layer, a barrier layer, a release liner, a tie coat, a transparent layer, a colored layer, a white layer, a reflective layer, a fluid transfer layer, a strength enhancing layer, a face coat, a print-receiving layer, a layer containing a print, a marking layer, a functional layer, etc. and combinations thereof. The resulting multi-layer laminate structure described herein can be used in various applications, including but not limited to: graphic applications, such as automotive and architectural packaging; reflective applications, such as road and traffic signs, trains, and other commercial vehicles; and label and packaging applications.

[0024] As used herein, the first direction or along the vertical axis is defined as being measured in a plane that is substantially perpendicular to the first face of the liner between the first face of the liner and the face material. When measured, this refers to the height of a given component, for example, the height of the adhesive dots within the applied pattern.

[0025] As used herein, the horizontal axis is defined as measured in a plane substantially parallel to the first face of the embossed liner between the first and second ends of the embossed liner. When measured, this refers to the width of a given component, e.g., the width of the adhesive dots within the applied pattern.

[0026] As used herein, the term "coating" includes a range of deposition and / or material transfer techniques other than transfer coating. For example, the term coating includes direct coating, spraying, brushing, dipping, and other methods. These and other aspects are all described in more detail herein.

[0027] As used herein, the term "super adhesion" means that the adhesive performs better than or equal to the cast adhesive at a lower coating weight than the cast adhesive.

[0028] As used herein, "gsm" means grams per square meter. Detailed Description

[0029] Adhesive laminate / adhesive-coated facestock

[0030] Adhesive regions and / or adhesive structures disposed on a substrate are described herein. In some embodiments, the adhesive regions and / or adhesive structures exhibit specific dimensional ratios as described herein. In some embodiments, the adhesive is a pressure sensitive adhesive (PSA). The PSA can be applied to a facestock such as a release liner or facestock using various techniques such as spraying. After application, the PSA can optionally be cured and / or otherwise processed. In some embodiments, the release liner and the PSA deposited thereon are then contacted with a facestock such as labelstock or a polymer film, thereby transferring the PSA at least partially to the facestock. The release liner can be removed at a later time to expose the PSA face and enable the user to adhere the facestock to a target substrate. In other embodiments, the facestock (e.g., labelstock or polymer film) and the PSA deposited thereon are then contacted with the release liner. The release liner can be removed at a later time to expose the PSA face and enable the user to adhere the facestock to a target substrate.

[0031] By using these structures, components, and / or techniques, a variety of PSA properties and deposition configurations are now achievable that were not possible prior to using conventional methods of depositing PSA onto facestock.

[0032] Also described are adhesive laminates and / or adhesively coated facing materials, particularly those produced using the methods described herein, and more particularly those produced by roll-to-roll coating of an adhesive onto the facing layer of a laminate. Many of these laminates can be configured to provide one or more of the functions detailed herein. However, it will be understood that the subject matter of the present invention includes laminates as described herein, which may, however, be produced by techniques other than the unique methods described herein.

[0033] Adhesive

[0034] The laminates / constructions described herein include one or more adhesives. The adhesive can be a PSA, a non-pressure sensitive adhesive, a hot melt adhesive, or a combination thereof. In some embodiments, the adhesive is a PSA. The PSA can be any known PSA. In some embodiments, the PSA is a solvent-based adhesive, an emulsion-based adhesive, or a non-emulsion-based adhesive. In some embodiments, the PSA is an emulsion adhesive. A hot melt PSA can also be used. The adhesive can be acrylic or any other available adhesive having the hardness and adhesion characteristics required for the laminate and / or the adhesively coated facing material. In certain embodiments, the adhesive should have a hardness sufficient to prevent extrusion of the adhesive from the laminate or article during processing.

[0035] Exemplary PSAs can be found in (1) Encyclopedia of Polymer Science and Engineering, Volume 13, Wiley-Interscience Publishers (New York, 1988); (2) Polymer Science and Technology, Volume 1, Interscience Publishers (New York, 1964); (3) those described in U.S. Patent Nos. 5,164,444, 5,183,459, and 5,264,532 (all assigned to Bernard) and U.S. Patent No. 5,385,965 (assigned to Bernard et al.); and (4) combinations thereof. The PSA can be a solvent-based adhesive or can be a water-based adhesive. Conventional PSAs can be used in the laminates / constructions described herein, including acrylic PSAs, rubber-based PSAs, and silicone-based PSAs. In one embodiment, the pressure sensitive adhesive comprises an acrylic emulsion adhesive.

[0036] In some embodiments, the pressure-sensitive adhesive is prepared by polymerizing an alkyl acrylate, a vinyl ester, a diester of a dicarboxylic acid, and an unsaturated acid. The alkyl acrylate typically contains from about 2 to about 12, or from about 4 to about 8 carbon atoms in the alkyl group. Examples of alkyl acrylates include, but are not limited to: ethyl acrylate, n-butyl acrylate, hexyl acrylate, 2-ethylhexyl acrylate, and isooctyl acrylate, with 2-ethylhexyl acrylate being preferred. In one embodiment, the alkyl acrylate is present in an amount of at least about 35%. In some embodiments, the alkyl acrylate is present in an amount of from about 35% to about 60% by weight.

[0037] The vinyl ester typically has from about 2 to about 12, or from about 4 to about 8 carbon atoms in the alkyl group. Examples of vinyl esters include, but are not limited to: vinyl acetate, vinyl propionate, vinyl butyrate, vinyl versatate, etc., with vinyl acetate being preferred. In some embodiments, the vinyl ester is present in an amount of from about 15% to about 35% or from about 20% to about 25% by weight.

[0038] The diesters of dicarboxylic acids include alkyl esters of unsaturated dicarboxylic acids such as maleic acid or anhydride and fumaric acid. The alkyl group typically contains from about 2 to about 20, or from about 4 to about 16, or from about 6 to about 12 carbon atoms. Examples of diesters of dicarboxylic acids include, but are not limited to: dibutyl fumarate, dioctyl fumarate; dihexyl maleate, didecyl maleate; bis(2-ethylhexyl) maleate; dibutyl fumarate; and bis(2-ethylhexyl) fumarate; and mixtures thereof. In some embodiments, the diester of dicarboxylic acid is present in an amount of from about 20% to about 35% by weight.

[0039] The unsaturated acid typically contains from about 2 to about 12, or from about 2 to about 6 carbon atoms. Examples of unsaturated acids include, but are not limited to: acrylic acid, methacrylic acid, itaconic acid, etc. In some embodiments, the unsaturated acid is present in an amount of from about 1% to about 3% or up to 5% by weight.

[0040] In an exemplary embodiment, the coating weight can be from 4 gsm to 60 gsm.

[0041] Release liner

[0042] In some embodiments, the laminates described herein can include one or more release liners. The liner can have a first side, a second side opposite the first side, a first edge, and a second edge opposite the second edge. The liner can be any available liner that provides the necessary support and release characteristics. The liner can be made of various materials including but not limited to paper or polymer film liners, or from various materials including but not limited to paper or polymer film liners. In one embodiment, the paper is thick enough to die cut the resulting laminate or article. In one embodiment, the liner has a laying flat property. In some embodiments, the liner has a machine glaze or finish. In some embodiments, the liner has a silicone retention layer. The retention layer provides adhesion between the release coating and the release liner. The silicone retention layer also prevents the silicone release coating from penetrating into the liner.

[0043] In the case of paper liners and other absorbent liners, these liners have a moisture content. To promote, prevent, or optimize patterning of the liner based on the moisture content, the moisture content can be varied and modified in various ways. Additional discussion regarding methods will be provided below.

[0044] In some embodiments, the release liner includes a liner having a release coating. The release coating of the release liner provides a peelable bond with the PSA or other adhesive. The release coating can be any composition that provides the desired peelable bond strength.

[0045] In one embodiment, the release coating is a silicone release coating. The release coating can be prepared by curing a silicone polymer in the presence of a controlled release agent. In some embodiments, the controlled release agent is a copolymer of a monofunctional silicone unit of the formula R3SiO 1 / 2 and a tetrafunctional silicone unit SiO 4 / 2 wherein R is an alkyl or alkenyl group. In one embodiment, the alkyl or alkenyl group contains from about 1 to about 12, or from about 1 to about 6 carbon atoms. Non-limiting examples of alkyl and alkenyl groups include methyl, ethyl, propyl, butyl, hexyl, vinyl, propenyl, butenyl, and hexenyl.

[0046] The controlled release agent typically reacts with a polysiloxane. The polysiloxane can be any polysiloxane useful for forming a release coating. Examples of useful polysiloxanes include, but are not limited to, vinyl-terminated polysiloxanes, hydroxy-terminated polysiloxanes, and epoxy-terminated polysiloxanes. In one embodiment, the polysiloxane is a functional polydialkylsiloxane, where the alkyl group contains from about 1 to about 6 carbon atoms. The alkyl groups independently include, but are not limited to, methyl, ethyl, propyl, butyl, pentyl, hexyl, or mixtures thereof. In one embodiment, the alkyl or alkenyl group contains from 1 to about 12, or from 1 to about 6 carbon atoms. The viscosity-average molecular weight of the polysiloxane is typically greater than 300,000 centipoise (cps). In another embodiment, the viscosity molecular weight of the polysiloxane is from about 300,000 to about 1,000,000 or greater. The polysiloxane can be represented by formula (I):

[0047] RO((Si(R)2O) x )—Si)—R (I)

[0048] wherein each R is independently defined as above, and x is an integer.

[0049] In some embodiments, the release coating is prepared with a crosslinking agent. In some embodiments, the crosslinking agent is a reactive polysiloxane, such as polydialkylsiloxane or polyhydroxyalkylsiloxane. The alkyl groups are the same as those described above.

[0050] The release coating can be applied in solvent form, solventless form, or emulsion form. To form the release coating, the release coating can be cured by any known curing process, such as heat, radiation, etc. This curing can be catalyzed with an organosilicon soluble complex compound of a Group VIII transition metal, such as platinum.

[0051] Commercially available release agents include, but are not limited to, GE SS-4335 (an organosilicon release agent in a non-reactive solvent). Commercially available polysiloxanes include, but are not limited to, GE SS-4331 (vinyl-terminated polydimethylsiloxane). Commercially available linking agents include, but are not limited to, GE SS-4300C (polymethylvinylsiloxane). Exemplary catalysts include, but are not limited to, the SS-8010 catalyst in toluene. These materials are commercially available from the Silicone Products Division of the General Electric Company. Similar organosilicon products are available from Dow Corning Corporation under the trade name Syl-off.

[0052] It will be understood that the subject matter of the present invention is not limited to any of the release coatings or release agents mentioned, but includes almost any release coating or release agent suitable for the intended end-use application. Further, although the subject matter of the present invention has been described in connection with a release liner, it will be understood that a suitably configured carrier film and other components can be used in place of the release liner.

[0053] Face material

[0054] Suitable face materials include, but are not limited to: synthetic papers such as polyolefin-type and polystyrene-type; various plastic films or sheets such as polyolefins, polyvinyl chloride, polyethylene terephthalate, polystyrene, polyurethane, polymethacrylate, and polycarbonate. Additional examples of suitable face materials include paper and cardboard. The face material can be or can include a multi-layer polymer sheet. The multi-layers can be co-extruded or the multi-layers can be laminated together. In one embodiment, the face material includes both co-extruded multi-layers and laminated multi-layers. Further, a white opaque film can be formed by adding a white pigment to one or more of the aforementioned synthetic resins and used as the face material. In one embodiment, a foamed film is used as the face material. The foamed film can be formed by conventional foaming operations. In another embodiment, the face material can be a laminate formed by combining a plurality of single-layer sheets made of the materials listed above. Examples of such laminates can include: a combination of cellulose fiber paper and synthetic paper, and a laminate of a combined cellulose fiber paper and a plastic film or sheet. In another suitable embodiment, the face material includes coated and uncoated paper, metallized paper, aluminum foil, laminated paper, and paper with a polymer material extruded on the surface of the paper. In certain variations, the face material can be coated with a liquid absorbent material. The selected face material can be porous or semi-porous. The face material can exhibit certain visibility characteristics such as opacity, color, and / or brightness. The face material can include water absorbency characteristics or other liquid absorbency characteristics. The face material can be conductive and / or include a conductive coating or region. A variety of commercially available face materials can be used, such as those available under the name TESLIN.

[0055] The thickness of the face material is optionally determined with reference to application-specific criteria. Such criteria can include the desired end-use. In one embodiment, the sheet thickness is in the range of about 10 μm to about 300 μm. In another embodiment, the sheet thickness is in the range of about 20 μm to about 200 μm. In yet another embodiment, the sheet thickness is in the range of about 30 μm to about 150 μm. Optionally, a primer treatment, corona discharge treatment, or plasma treatment can be applied to the face material to increase the bond strength between the face material and the dry face coating composition formed on the surface of the face material.

[0056] In certain embodiments described herein, the facing material exhibits one or more functions or functional properties. For example, the facing material can be selected to achieve or facilitate: indication, such as visual indication of a liquid; venting, such as guiding or allowing air or gas to flow through the thickness of the facing material; water or liquid retention within the facing material; discharge or conductivity of the facing material; chemical transport through the thickness of the facing material; sound channeling through the thickness of the facing material; and / or combinations of these functions or features.

[0057] Optional layer

[0058] The adhesive-coated facing materials and / or laminates described herein can include one or more additional layers or components. Non-limiting examples of such layers include: protective layers, tie coats, transparent layers, colored layers, white layers, reflective layers, fluid transfer layers, strength promoting layers, surface coats, print-receiving layers, layers containing prints, marker layers, functional layers, and the like.

[0059] Lamina properties

[0060] The laminates described herein can have specific and useful properties or functions. In some embodiments, the techniques described herein enable the formation of laminates in which the transfer, propagation, and / or migration of liquids, gases, sound waves, electric currents, and / or other reagents or elements can occur and be controlled in the Z-direction through or across the laminate. As mentioned herein, the "Z-direction" refers to the direction through the thickness dimension of the laminate or a portion thereof, and thus the "X-direction" and / or "Y-direction" refer to directions perpendicular to the Z-direction and corresponding to the width dimension and length dimension of the laminate.

[0061] Non-limiting representative examples of laminates with specific functions provided by the subject matter of the present invention include liquid indicator laminates, venting laminates, water-absorbing laminates, sound channeling laminates, conductive laminates, and laminates having combinations of these functions and / or laminates having combinations of one or more of these functions and additional functions.

[0062] For example, a liquid indicator laminate can be produced such that the rate of indicator color change is related to the facing material selection and the porosity of the patterned adhesive. Discontinuous structures (such as those created by holes in the adhesive layer or region) can allow, for example, liquid to flow from one side of the adhesive through the discontinuous adhesive to the other side and produce a permanent color change when a dye or other reagent in the functional coating within the laminate dissolves.

[0063] In one embodiment, a liquid indicator laminate is provided. The rate or speed of indicator color change is related to facing material properties such as the absorbency of the liquid and the porosity of the patterned adhesive in the Z-direction. The indication is typically irreversible and can be measured by color change or by simple visual comparison.

[0064] The discoloration of a face or region of a laminate can be measured and quantified by optical changes, such as by CIE Lab or by simple visual comparison. The discoloration can be permanent or non-permanent. The discoloration can also be temporary and revert to an initial state after a period of time. In some embodiments, the period of time is predetermined.

[0065] This transport phenomenon through the discontinuities in the adhesive in the Z-direction can be implemented in other label applications, particularly pressure-sensitive adhesive labels, such as labels for venting a substrate, for example, by air channels in the Z-direction, labels for marking a wet substrate, for example, by liquid channels in the Z-direction, discharge in the Z-direction, chemical transport from one layer to another in the Z-direction, and / or sound channels in the Z-direction. This phenomenon enables a medium or reagent to pass through, transfer to, and / or migrate from one side of the adhesive region of the laminate to the other side. Although the medium penetration or transport is mentioned as being in the Z-direction, it will be understood that the subject matter of the present invention is not limited thereto and can also include penetration / transport in the X-direction and / or Y-direction.

[0066] In some embodiments, the laminates described herein include a layer or region of a secondary adhesive. The secondary adhesive is typically used to adhere the laminate to a target substrate. The secondary adhesive can include one or more adhesives that are the same as or different from the adhesive of the patterned or porous adhesive. Descriptions of representative examples of the secondary adhesive are provided herein. In such an adhesive configuration, the primary adhesive can be coated onto the face stock, the secondary adhesive can be coated onto the release liner, and the coated adhesives and the release liner can be laminated together such that the primary adhesive and the secondary adhesive are in direct contact with each other. Alternatively or additionally, both the primary adhesive and the secondary adhesive can be coated onto the face stock or the release liner and then laminated together. It is contemplated that the lamination of the primary adhesive and the secondary adhesive with respect to the face stock and the release liner can be face stock, primary adhesive, secondary adhesive, and release liner or face stock, secondary adhesive, primary adhesive, and release liner. Regardless of the order of the primary adhesive and the secondary adhesive, at least one of the primary adhesive and the secondary adhesive is contemplated to be patterned, considering that the other adhesive can be continuous.

[0067] In some embodiments, a series of different arrangements of layers and components can be utilized. In some embodiments using a patterned adhesive, such as a layer of discontinuous adhesive, the layer is disposed between the functional face stock and the liner or functional layer. Additionally, in a liquid indicator laminate, the patterned adhesive can be disposed between the functional face stock and a layer or region of a functional reagent that is sensitive to a liquid passing through the laminate. Additionally, in a liquid indicator laminate, the layer or region of the functional reagent can be disposed between the patterned adhesive and the carrier layer.

[0068] The techniques and features described herein enable the production of adhesive laminates and / or adhesively coated facing materials having fluid / air management properties, controlled removability, and / or unique thermal and / or electrical conductivity. Additionally, the use of these techniques and features enables the reduction of materials such as adhesives and thereby cost savings. However, it will be understood that the subject matter of the present invention includes adhesively coated facing materials and laminates described herein formed by methods other than those described herein.

[0069] The methods of the subject matter of the present invention can be carried out in batch, continuous, or semi - continuous fashion. For continuous methods, typical processing speeds are in the range of about 100 m / minute to 1,000 m / minute. However, it will be understood that the subject matter of the present invention is not limited to these speeds and includes processing speeds less than 100 m / minute and / or speeds greater than 1,000 m / minute.

[0070] Method

[0071] The various components of the system have been discussed. Exemplary methods and methodologies of operation will be discussed. Patterning of the liner material and the adhesive

[0072] The inventors have found that patterning the liner of the laminate promotes super - strong adhesion to rough substrates.

[0073] In general, the Johnson - Kendall - Roberts peel model ("JKR") provides a framework for understanding angle - dependent micro - peeling. Specifically, these can be the models of Equation II:

[0074]

[0075] This equation helps describe the non - linear relationship between the peel force F, the peel angle θ, a given backing modulus E, and the fracture energy G. The average peel force is greater than the case where the peel angle is held constant at 90 degrees because the cosine of 90 degrees is zero, thus maximizing the term 1 - cosθ. As can be seen, changing this angle will have a significant impact on adhesion. Also, the peak peel force can be considered the effective peel force rather than the average. Where b can be the width parameter of the object. However, if fibrillation can be maximized, the force required for peeling from a rough substrate can be enhanced. Thus, the formation and growth of fibrils during debonding are crucial for the peel strength and tack of the adhesive.

[0076] For rough surfaces, fibrillation can be maximized by two vectors. First, the padding material can be patterned. This patterning of the padding material is done to increase the surface area of the adhesive that will later be applied to the padding material. The patterned structure is conducive to fibrillation. In addition, the adhesive itself can also be patterned. As a result of the dual patterning, additional fibrillation occurs, resulting in more energy dissipation and a higher peel force being required to break the bond. By way of illustration, Figure 1 this general process of patterning the padding is discussed.

[0077] As can be seen in Figure 1 an exemplary process of patterning an exemplary padding is shown. First, the pre-silicated padding 100 is passed through the patterning mechanism 102 and the pressure roller 104. The patterning mechanism 102 can be patterned in various ways. This can include, but is not limited to, using Teflon dots, a steel mesh pattern, an engraved roller, a sleeve on the outside of the patterning mechanism, or other such methods known in the art to deform the padding. The result is the patterned padding 106. The pressure the padding is subjected to is 5 PSI to 150 PSI. In an exemplary embodiment, the working cylinder pressure (which achieves good embossing) is in the range of about 20 psi to about 120 psi. In this embodiment, the corresponding estimated line pressure is about 50 pli to about 400 pli, and the actual roll nip pressure is greater than 300 psi.

[0078] After the padding is deformed, to form the patterned padding 106, the adhesive 108 is applied to the patterned padding. In an exemplary embodiment, the adhesive 108 is applied by any known method in the art, including but not limited to spraying, printing, gravure printing, and additional methods.

[0079] After the adhesive 108 is applied, the patterned padding 106 and the patterned adhesive 108 can be subjected to an optional moisture conditioning unit 110. Depending on the characteristics of the pre-silicated padding 100 and the subsequent patterned padding 106, this step can occur before the addition of the adhesive 108, so the moisture conditioning unit 110 will be before the padding is patterned. In some embodiments, the moisture conditioning can be a steam foil, an oven, a liquid water applicator, or other such solutions known in the art. It may be desirable for the pre-silicated padding 100 to be more or less extensibly deformable and this can be regulated by its moisture content. In an exemplary embodiment, the moisture content can be 2% to 10%.

[0080] After the adhesive 108 is applied or dried 110, the facestock 112 can be laminated to the adhesive 108, thereby forming an exemplary laminate of the embossed liner 104, the patterned adhesive 108, and the facestock 112. This is merely exemplary and may have additional layers (as described above and not repeated for brevity). By the application of the facestock 112, the embossed liner 104 with the patterned adhesive 108 is protected and can be transported and handled without deforming the pattern.

[0081] The adhesive can be patterned in a variety of ways. Specifically, referring to FIG. 2A, an exemplary embodiment of a 2D adhesive application pattern is shown. In this pattern, there are peaks 200 of adhesive, with spaces 202 therebetween. Although shown for purposes of clarity and understanding, these peaks are merely exemplary and the shapes shown, including any given height (H) or width (W), are not necessarily to scale and are shown to increase understanding of the exemplary embodiment. This exemplary pattern can be produced as a regular pattern, thereby achieving uniformity, consistency, and / or balance in terms of shape, arrangement, and / or pattern orientation variation across the embossed liner, as well as repetitive homogeneity. As can be seen in this embodiment, the exemplary pattern can be a repeating pattern, where the adhesive is regular in terms of shape, arrangement, and / or pattern orientation and the heterogeneity is repetitive. This exemplary embodiment is a discontinuous pattern because one or more regions, portions, sites, or spaces of the liner are not covered by the adhesive. Alternatively, in this or other embodiments, the exemplary pattern can be an irregular pattern, or uneven or unbalanced in terms of shape, arrangement, and / or pattern orientation variation and the heterogeneity is non-repetitive. In embodiments where the adhesive is in a regular discontinuous adhesive pattern, the coating weight can be in the range of 3 gsm to 40 gsm.

[0082] Referring now to FIG. 2B, an alternative embodiment of the adhesive pattern is shown. In this embodiment, there is a minimum layer that is cast or continuously coated, where all of one surface of the backing is covered with adhesive to a certain level. Then, the peaks 200 of the adhesive can be overlaid on top of the cast adhesive 204. This exemplary pattern can be produced as a regular pattern, thereby achieving uniformity, consistency, and / or balance in terms of shape, arrangement, and / or pattern orientation variation across the embossed backing, as well as repetitive homogeneity. As can be seen in this embodiment, the exemplary pattern can be a repeating pattern, where the adhesive is regular in terms of shape, arrangement, and / or pattern orientation and the heterogeneity is repetitive. Alternatively, in this embodiment or other embodiments, the exemplary pattern can be an irregular pattern, or uneven or unbalanced in terms of shape, arrangement, and / or pattern orientation variation and the heterogeneity is non-repetitive. In embodiments where the adhesive is in a regular continuous adhesive pattern, the coating weight of the continuous cast portion can range from about 0.5 gsm to about 8 gsm. This embodiment or another embodiment allows the percentage of the adhesive coating weight in the continuous cast to be from 0% to about 70% of the total adhesive.

[0083] The adhesive can be applied using techniques known in the art. For example, in some embodiments, the adhesive is applied to a tensioned, temporarily deformed substrate or web using a slot die. The thickness of the coating can be controlled, for example, by metering using a metering pump or by other techniques known in the art. The die body can include a manifold to evenly distribute the adhesive flow across the slot width. The appearance of the adhesive layer on the backing or web depends on the coating gap or coating angle between the die body and the roll. In some embodiments, the coating can be achieved by energizing one or more substrates to be coated and the adhesive itself. In another embodiment, such coating can be performed by electrostatic deposition.

[0084] For clarity, assume that the patterned adhesive is a spherical cap in any kind of stacked arrangement, given a certain covered footprint area. Refer to Figure 3 This is illustrated in the figure. In this figure, it can be seen that there is a "cap" portion of a sphere having a height "h", a radial width or crown radius "a", a radius "r", and an angle "θ". The adhesive feature area (V 冠 ) can be represented by Equation (III):

[0085]

[0086] This can be compared to the coating weight (c, in μm) of the backing, where K is the point footprint coverage area (V 浇 ) of the cast backing, as represented by Equation (IV):

[0087]

[0088] In one exemplary embodiment, the applied patterned adhesive has a peak height (h) and a width (a + a or 2a), and the ratio between the peak height and the width is from about 0.02 to about 0.05. In this or another exemplary embodiment, the average height is in the range of about 20 μm to about 40 μm. In this or another exemplary embodiment, the average width is in the range of 0.4 mm to about 2.0 mm. Further, the coverage of the applied patterned adhesive is from about 40% to about 60% of the gasket.

[0089] Examples

[0090] All examples were produced by: contacting a first face of a gasket with a deformable member to at least temporarily deform the gasket by contact with the deformable member; and while the gasket is temporarily deformed, substantially simultaneously applying an adhesive in a substantially uniform manner to at least a portion but not the entire first face of the gasket while the gasket is at least temporarily deformed, thereby forming a pattern of the adhesive. Comparative examples were coated with the adhesive instead of pattern-coated.

[0091] Examples 1, 2, and 3 and Comparative Example A

[0092] Four different samples were prepared, each using S692N (available from Avery Dennison Corporation, Mentor, Ohio) as its adhesive. S692N is a clear general-purpose permanent acrylic adhesive that exhibits a balance of high cohesive strength for durable performance on squeezable containers and adhesion to low surface energy substrates, and is specifically designed to exhibit excellent wetting characteristics and short-term removability.

[0093] The configuration of Example 1 can be seen in Figure 4 Example 1 was conducted where adhesive 400 was applied to a rough substrate 402 over a patterned gasket 404 (not shown as patterned here for clarity). As discussed above, due to the additional factor of peak-to-peak contact, the adhesion to a rough surface will be even greater, i.e., the thicker regions of the adhesive have a greater likelihood of interacting with the higher features on the surface. Thus, enhanced fibrillation is simply the result of a higher adhesive thickness at that location. The facestock is 1 mil clear PET since the adhesive was applied using a patterned silicone-coated liner. Further, Example 1 was coated at different coating weights of 10 gsm, 15 gsm, and 20 gsm on the glossy side.

[0094] Figure 5Example 2 was described. Example 2 was conducted where the facing material was patterned to match the patterned adhesive. The facing was 2 mil BG40 white, i.e., supercalendered glassine (available from Avery Dennison Corporation, Mentor, Ohio), where the adhesive was directly coated on the matte side of the patterned BG40. The adhesive was in contact with the rough substrate. Additionally, Example 2 was coated at different coating weights of 10 gsm, 15 gsm, and 20 gsm.

[0095] Example 3 was conducted where the facing material was patterned to match the patterned adhesive. The facing was 2 mil BG40 white, i.e., supercalendered glassine (available from Avery Dennison Corporation, Mentor, Ohio), where the adhesive was directly coated on the silicated side of the patterned BG40. The adhesive was in contact with the rough substrate. Additionally, Example 3 was coated at different coating weights of 10 gsm, 15 gsm, and 20 gsm.

[0096] Comparative Example A was 1 mil clear PET with the same adhesive as cast on a rough substrate. Additionally, Example A was coated at different coating weights of 10 gsm, 15 gsm, and 20 gsm.

[0097] The coating weights and the associated 90 - degree peel adhesion tests with cardboard (rough substrate) at a dwell time of 20 minutes at room temperature are all summarized in Table 1 below:

[0098] Table 1

[0099] Peel value at coating weight 1 2 3 A 10 2.2 0.9 0.7 1 15 3.3 1.7 1.7 1.8 20 5.8 1.9 2 3.7

[0100] All coating weights are in gsm and all peel values are in N / in.

[0101] As can be seen, at 10 gsm, the peel value of Example 1 was 1.2 N / in greater than that of Comparative Example A as cast, at 15 gsm it was 1.5 N / in greater than that of Comparative Example A as cast, and at 20 gsm it was 2.1 N / in greater than that of Comparative Example A as cast. This demonstrates that at the same coating weight, when the adhesive is pattern - coated and the liner is patterned, the adhesion of the adhesive to the rough substrate can be increased by up to about 55%. The contact of the pattern of the adhesive with the rough substrate results in enhanced adhesion to the rough substrate with less adhesive used than in a continuous uniform cast.

[0102] Examples 4 and 5 and Comparative Example B

[0103] Three different samples were prepared, each using as discussed above S692N (available from Avery Dennison Corporation, Mentor, Ohio) is used as its adhesive.

[0104] Figure 6 Example 4 is illustrated. Example 4 is conducted where the facestock 604 is patterned in a manner that matches the patterned adhesive 600. The facestock is 2 mil BG40 white, i.e., supercalendered glassine (available from Avery Dennison Corporation, Mentor, Ohio), and the adhesive is directly coated on the matte side of the patterned BG40. The adhesive is in contact with the smooth substrate 602. Additionally, Example 4 is coated at different coating weights of 10 gsm, 15 gsm, and 20 gsm. Example 5 is the same, except that the adhesive is coated at different coating weights of 10 gsm, 15 gsm, and 20 gsm on the silicated side of the patterned facestock.

[0105] Comparative Example B is 1 mil clear PET with the same adhesive as cast on a smooth substrate. Additionally, Comparative Example B is coated at different coating weights of 10 gsm, 15 gsm, and 20 gsm.

[0106] The coating weights and the associated 90 - degree peel adhesion tests with cardboard (rough substrate) at room temperature with a dwell time of 20 minutes are all summarized in Table 2 below:

[0107] Table 2

[0108] Peel value at coating weight 4 5 B 10 2.2 1.9 4.8 15 3.4 4.6 7.1 20 5.5 5.6 8.2

[0109] All coating weights are in gsm and all peel values are in N / in.

[0110] As can be seen, at 10 gsm, 15 gsm, and 20 gsm, the peel values of Examples 4 and 5 are less than those of Comparative Example B which is cast. This demonstrates that at the same coating weight, when pattern - coated and the liner is patterned, the adhesion of the adhesive to the smooth substrate is not improved.

[0111] All definitions as defined and used herein shall be understood to be prior to dictionary definitions, definitions in incorporated - by - reference documents, and / or ordinary meanings of the defined terms.

[0112] Unless expressly stated to the contrary, a noun without a modifier of quantity as used herein in the specification and claims shall be understood to mean "at least one / kind / party". As used herein in the specification and claims, the phrase "and / or" (if any) shall be understood to mean "either or both" of the elements so combined, i.e., elements that may be present jointly in some cases and separately in other cases. Multiple elements listed with "and / or" shall be construed in the same manner, i.e., "one or more" of the elements so combined. Other elements may optionally exist in addition to those specifically recited by the "and / or" clause, whether related or unrelated to those specifically recited. Thus, as a non-limiting example, when used in conjunction with open-ended language such as "comprising", a reference to "A and / or B" may, in one embodiment, refer to only A (optionally including elements other than B); in another embodiment, may refer to only B (optionally including elements other than A); in yet another embodiment, may refer to both A and B (optionally including other elements); and so on. As used herein in the specification and claims, "or" shall be understood to have the same meaning as "and / or" as defined above. For example, when separating items in a list, "or" or "and / or" shall be understood to be inclusive, i.e., including at least one of a plurality of elements or items in a list, but also including more than one, and optionally including additional unlisted items. Only terms expressly stating the contrary, such as "only one of... " or "exactly one of... ", or when used in a claim "consisting of... ", will refer to including exactly one element of a plurality of elements or items in a list. Generally, when preceded by an exclusive term such as "either", "one of... ", "only one of... " or "exactly one of... ", the term "or" as used herein shall be understood to denote only exclusive alternatives (i.e., "one or the other, but not both"). When used in a claim, "consisting essentially of... " shall have its ordinary meaning as used in the field of patent law.

[0113] As used herein in the specification and claims, the phrase "at least one" when referring to a list of one or more elements should be understood to mean at least one element selected from any one or more of the elements in the list of elements, but not necessarily including each and every element specifically listed in the list of elements and at least one of each element, and does not exclude any combination of elements in the list of elements. This definition also allows for the optional presence of elements other than those specifically recited in the list of elements referred to in the phrase "at least one", whether related or unrelated to those specifically recited. Thus, as a non-limiting example, "at least one of A and B" (or equivalently, "at least one of A or B", or equivalently, "at least one of A and / or B") can, in one embodiment, refer to at least one A, optionally including more than one A, with no B present (and optionally including elements other than B); in another embodiment, it can refer to at least one B, optionally including more than one B, with no A present (and optionally including elements other than A); in yet another embodiment, it can refer to at least one A, optionally including more than one A, and at least one B, optionally including more than one B (and optionally including other elements); and so on.

[0114] An embodiment is a way or example of implementing the present disclosure. References in the specification to "an embodiment", "one embodiment", "some embodiments", "a particular embodiment", or "other embodiments", etc., mean that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least some embodiments of the invention, but not necessarily in all embodiments of the invention. The various occurrences of "an embodiment", "one embodiment", "some embodiments", "a particular embodiment", or "other embodiments", etc., do not necessarily all refer to the same embodiment.

[0115] If the specification states that a component, feature, structure, or characteristic "may", "might", or "could" be included, it is not necessary to include that particular component, feature, structure, or characteristic. If the specification or claims refer to an element without a quantifier, this does not mean that there is only one such element. If the specification or claims refer to "additional" elements, this does not exclude the presence of more than one additional element.

[0116] As used in this specification and the appended claims, including as used in the examples, unless otherwise expressly specified, all numbers may be read as if prefaced by the word "about" or "approximately", even if the term does not expressly appear. When describing dimensions and / or positions, the phrase "about" or "approximately" may be used to indicate that the described value and / or position is within a reasonable expectation of the value and / or position. For example, a numerical value may have a value of + / -0.%, + / -1%, + / -2%, + / -5%, + / -10% of the stated value (or range of values), etc. Any numerical range recited herein is intended to include all sub-ranges subsumed therein.

[0117] In addition, any method of carrying out the present disclosure may be performed in an order different from those described herein. Accordingly, the order of the method should not be construed as limiting unless expressly stated. It will be appreciated that some steps of the method performed in a different order may achieve similar results.

[0118] In the claims, as well as in the foregoing specification, all transitional phrases such as "comprising", "including", "carrying", "having", "containing", "involving", "holding", "consisting of", etc. are to be understood to be open-ended, i.e., to mean including but not limited to. As set forth in the United States Patent and Trademark Office's Manual of Patent Examining Procedure, only the transitional phrases "consisting of" and "consisting essentially of" should be closed or semi-closed transitional phrases, respectively.

[0119] In the foregoing description, certain terms have been used for the purposes of brevity, clarity and understanding. Since such terms are used for descriptive purposes and are intended to be broadly construed, they do not imply any unnecessary limitations beyond the requirements of the prior art.

[0120] In addition, the description and illustration of the various embodiments of the present disclosure are exemplary, and the present disclosure is not limited to the exact details shown or described.

Claims

1. A method of patterning an adhesive layer, comprising: Providing a backing having a first face, a second face, a first edge, and a second edge; Contacting the first face of the backing with a deformable member to at least temporarily deform the backing by the contact with the deformable member; And While temporarily deforming the backing, substantially simultaneously applying an adhesive to at least a portion but not the entire first face of the backing in a substantially uniform manner while the backing is at least temporarily deformed, thereby forming a pattern of the adhesive; And Contact of the pattern of the adhesive with a rough substrate enables enhanced adhesion to the rough substrate with less adhesive than in continuous coating.

2. The method according to claim 1, wherein the adhesive is applied in a discontinuous manner.

3. The method according to claim 1, wherein the adhesive is applied in a continuous manner.

4. The method according to claim 1, wherein the backing is a paper-derived backing having a moisture content.

5. The method according to claim 4, further comprising, prior to contact: Adjusting the moisture content of the backing.

6. The method according to claim 5, wherein adjusting the moisture content comprises: Adding moisture to the backing.

7. The method according to claim 5, wherein adjusting the moisture content comprises: Removing moisture from the backing.

8. The method according to claim 4, further comprising: Adjusting the moisture content of the backing after applying the adhesive.

9. The method according to claim 1, wherein the backing comprises PET.

10. The method according to claim 1, wherein at least a portion of the backing is silicated.

11. The method according to claim 1, further comprising: Laminating the backing with a facing material.

12. The method according to claim 1, wherein the applied adhesive has a peak height in a first direction and a peak width between the first edge and the second edge, and wherein the ratio between the peak height and the width is from about 0.02 to about 0.

05.

13. The method according to claim 12, wherein the average height is in the range of about 20 μm to about 40 μm.

14. The method according to claim 12, wherein the average width is in the range of 0.4 mm to about 2.0 mm.

15. The method according to claim 12, wherein the percentage of the first face of the backing covered by the peaks of the adhesive is from about 40% to about 60%.

16. The method according to claim 1, wherein the adhesive is a pressure-sensitive adhesive or a hot-melt adhesive applied at a weight of from about 6 gsm to about 20 gsm.

17. The method according to claim 1, wherein the adhesion of the adhesive to the rough substrate is about 10% to about 50% higher than in the case of the same coating weight.

18. The method according to claim 1, wherein the deformable member is a roll having a patterned surface etching.

19. The method according to claim 1, wherein the deformable member is a roll having a patterned surface attachment.

20. The method according to claim 1, wherein the deformation step is carried out at a pressure of from about 5 PSI to about 150 PSI.

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