Hot melt adhesive

Abstract

Compositions, particularly pressure sensitive adhesive compositions, such as hot melt pressure sensitive adhesive compositions, and laminates using the same are disclosed. Specifically, discussed herein is a hot melt pressure sensitive adhesive composition comprising: a polyol ester; a styrene-isoprene-styrene block copolymer; a binder; a photoinitiator; and naphthenic oil; the present invention relates to a composition, or a composition, comprising: a styrene-isoprene-styrene block copolymer; a polybutylene polymer; a photoinitiator; and a tackifier; and related laminates and label constructions thereof.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of U.S. Provisional Application No. 63 / 481,613, filed January 26, 2023, the entire contents of which are incorporated herein by reference. Technical Field

[0002] The present disclosure generally relates to hot melt adhesives. More specifically, hot melt pressure-sensitive adhesive compositions comprising: a polyol ester; a styrene-isoprene-styrene block copolymer; a cling agent; a naphthenic oil; and a photoinitiator; or compositions comprising: a styrene-isoprene-styrene block copolymer; a polybutylene polymer; a photoinitiator; and a tackifier; and related laminate and label constructions using the compositions described herein. Background Art

[0003] Pressure-sensitive adhesives are used in a variety of applications, such as labeling, packaging, and other assembly purposes. Pressure-sensitive adhesives are materials that adhere with finger pressure without activation and are aggressively tacky and permanently tacky at room temperature. Most pressure-sensitive hot-melt formulations are tacky below room temperature and become tacky above their glass transition temperature.

[0004] Generally, pressure sensitive adhesives relate to solution / solvent-based adhesives, water / emulsion-based adhesives and hot melt adhesives. The use of solvent-based pressure sensitive adhesives is reduced because of their shortcomings, including complicated solvent recovery, solvent discharge into the environment, and solvent high flammability causing workplace hazards. Similarly, the use of water-based pressure sensitive adhesives is also accompanied by many disadvantages. Water-based pressure sensitive adhesives need to remove water, resulting in an energy-intensive process. The evaporation of water also results in uneven coating of the adhesive, and the drying of the adhesive composition limits the coating speed.

[0005] Therefore, solvent-free technologies for producing PSAs are becoming increasingly important. Hot-melt pressure-sensitive adhesives (PSAs) are particularly desirable because the lack of solvent or water in the adhesive formulation reduces the energy required to form the adhesive layer and mitigates the environmental issues associated with solvent-based adhesives. Hot-melt pressure-sensitive adhesives are widely used in packaging applications, where high melt viscosities resulting in high bond strength are preferred. However, for label applications, low melt viscosity and fast bonding performance are desirable characteristics, and therefore, the use of hot-melt pressure-sensitive adhesives in label applications requires a different formulation approach.

[0006] Therefore, there is a need to provide improved hot melt pressure sensitive adhesive compositions that exhibit excellent adhesive properties in label applications and are economical. Summary of the Invention

[0007] An exemplary embodiment relates to a composition comprising: a polyol ester; a styrene-isoprene-styrene block copolymer; a binder; a photoinitiator; and a naphthenic oil. This embodiment or another exemplary embodiment may provide an antioxidant. This embodiment or another exemplary embodiment may provide that the photoinitiator is present in the composition at about 1.8 weight percent based on the weight of the composition. This embodiment or another exemplary embodiment may provide a first plasticizer. This embodiment or another exemplary embodiment may provide a block copolymer having: a styrene content of 25 weight percent and polystyrene of 17.5 weight percent; and butadiene. This embodiment or another exemplary embodiment may provide an elastomer having a polystyrene-polyisoprene block structure. This embodiment or another exemplary embodiment may provide that the polyol ester is a pentaerythritol-esterified rosin. This embodiment or another exemplary embodiment may provide that the binder comprises isotactic propylene repeat units having a random ethylene distribution. This embodiment or another exemplary embodiment may provide that the percentage of the polyol ester is between about 35% and about 50% by weight; the percentage of the styrene-isoprene-styrene block copolymer is between about 10% and about 40% by weight; and the percentage of the naphthenic oil is between about 10% and about 25% by weight. This embodiment or another exemplary embodiment may provide a laminate comprising: a facestock layer; wherein the facestock layer has a first side and a second side; an adhesive layer comprising a composition comprising a polyol ester; a styrene-isoprene-styrene block copolymer; a binder; and a naphthenic oil, the adhesive layer being applied to at least a portion of the second side of the facestock layer after curing.

[0008] Further exemplary embodiments relate to a composition comprising: a styrene-isoprene-styrene block copolymer; a polybutylene polymer; a photoinitiator; and a tackifier. This embodiment or another exemplary embodiment may provide that the tackifier comprises a cycloaliphatic hydrocarbon resin. This embodiment or another exemplary embodiment may provide an antioxidant. This embodiment or another exemplary embodiment may provide that the photoinitiator is present in the composition at about 1.3 weight percent based on the weight of the composition. This embodiment or another exemplary embodiment may provide a laminate comprising: a face stock layer; wherein the face stock layer has a first side and a second side; an adhesive layer comprising a cured styrene-isoprene-styrene block copolymer; a polybutylene polymer; and a tackifier composition, wherein the tackifier comprises a cycloaliphatic hydrocarbon resin and is applied to at least a portion of the second side of the face stock layer. This embodiment or another exemplary embodiment may provide that the tackifier comprises an aromatic modified aliphatic hydrocarbon resin. This embodiment or another exemplary embodiment may provide that the average molecular weight (M) of the tackifier w ) between about 1600 g / mol and 2800 g / mol. This embodiment or another exemplary embodiment may provide an antioxidant. This embodiment or another exemplary embodiment may provide that the photoinitiator is present in the composition at about 1.3 weight percent, based on the weight of the composition. This embodiment or another exemplary embodiment may provide a laminate comprising: a facestock layer; wherein the facestock layer has a first side and a second side; an adhesive layer comprising a styrene-isoprene-styrene block copolymer; a polybutylene polymer; and a tackifier, wherein the tackifier comprises an aromatic-modified aliphatic hydrocarbon resin and is applied to at least a portion of the second side of the facestock layer after curing. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] The accompanying drawings are included to provide a further understanding of the exemplary embodiments and are incorporated in and constitute a part of this specification, and illustrate various embodiments of the exemplary embodiments and, together with the description, serve to explain the principles of the present disclosure. As will be appreciated, the subject matter described herein is capable of other and different embodiments, and its several details are capable of modifications in various respects, all without departing from the claimed subject matter. Therefore, the drawings and description are to be regarded as illustrative rather than restrictive. In the drawings: Figure 1 An exemplary embodiment of a laminate construction described herein is shown, comprising a facestock layer described herein, a pressure sensitive adhesive layer, and an optional release layer.

[0010] Figure 2Exemplary embodiments of laminate constructions described herein are shown, comprising a facestock layer as described herein, a pressure sensitive adhesive layer, and optionally a release layer, an optional coating, and optionally printed indicia.

[0011] definition As used herein, "hot melt pressure sensitive adhesive" refers to a pressure sensitive adhesive comprising a thermoplastic material in a state bonded to a substrate.

[0012] As used herein, the term "label" refers to a two-dimensional piece of paper, a two-dimensional piece of fabric, a two-dimensional piece of plastic, or a two-dimensional piece of similar material that is configured to be attached to an object and provide information about the object and / or decorate it. The label can be of any suitable shape or design, such as, for example, rectangular, square, circular, oval, triangular, polygonal, and irregular shapes. The label can have sharp, rounded, or irregular edges and corners. The label can be formed from a laminate as described herein with printed indicia thereon.

[0013] As used herein, the term "facestock layer" refers to one or more layers of film material (such as paper, polymer film, metal foil, or a combination thereof) to which printed indicia is added and optionally corona treated. The facestock layer has two sides, including a first side that faces outward and can receive printed indicia, and another second side that faces inward and can receive an adhesive layer.

[0014] As used herein, the term "adhesive layer" refers to one or more layers of the same or different hot melt pressure sensitive adhesive applied to a portion of the second surface of the facestock layer.

[0015] As used herein, the phrase "release liner" refers to a film (typically paper or polymer film, often used in manufacturing processes) used to prevent premature adhesion of sticky surfaces. It is coated on one or both sides with a release agent that provides a release effect to any type of sticky material, such as an adhesive or mastic.

[0016] As used herein, the phrase "printed indicia" refers to any alphanumeric or special character string used to convey information (e.g., name, address or mailing address, telephone number, prescription number, etc.) and / or provide aesthetic appeal. The indicia may be printed by any suitable means, including hand printing, typewriter printing, or conventional printing (e.g., flexographic printing, offset printing, inkjet printing, laser inkjet printing, videojet printing, thermal transfer printing, direct printing, gravure printing, etc.).

[0017] As used herein, the term "coating" refers to a coating material disposed on and in direct contact with an underlying backing film or other layer. DETAILED DESCRIPTION

[0018] Disclosed are novel compositions, particularly pressure-sensitive adhesive compositions, such as hot melt pressure-sensitive adhesive compositions, and laminates using the compositions. Specifically, the present invention discusses a hot melt pressure-sensitive adhesive composition comprising: a polyol ester; a styrene-isoprene-styrene block copolymer; a binder; and a naphthenic oil; or a composition comprising: a styrene-isoprene-styrene block copolymer; a polybutylene polymer; and a tackifier; and related laminates and label constructions.

[0019] Adhesives The laminates / structures described herein comprise one or more adhesives. The adhesive(s) may be a pressure-sensitive adhesive (PSA), a non-pressure-sensitive adhesive, a hot melt adhesive, or a combination thereof. In some embodiments, the adhesive is a PSA. The PSA may be any known PSA. In some embodiments, the PSA is a solvent-based adhesive, an emulsion adhesive, or a non-emulsion adhesive. In some embodiments, the PSA is an emulsion adhesive. Hot melt PSAs may also be used. The adhesive may be an acrylic adhesive or any other useful adhesive having the hardness and adhesion required for the laminate and / or adhesive-coated facestock. In certain embodiments, the adhesive should have sufficient hardness to prevent the adhesive from being squeezed out of the laminate or article during processing. Exemplary PSAs can be found in (1) Encyclopedia of Polymer Science and Engineering, Vol. 13, Wiley-Interscience Publishers (New York, 1988); (2) Polymer Science and Technology, Vol. 1, Interscience Publishers (New York, 1964); (3) those described in U.S. Pat. Nos. 5,164,444; 5,183,459; and 5,264,532 (all to Bernard) and U.S. Pat. No. 5,385,965 (to Bernard et al.); and (4) combinations thereof. The PSAs can be solvent-based adhesives or water-based adhesives. Conventional PSAs, including acrylic-based PSAs, rubber-based PSAs, and silicone-based PSAs, can be used in the laminates / structures described herein. In one embodiment, the pressure-sensitive adhesive comprises an acrylic emulsion adhesive.

[0020] In an exemplary embodiment, the adhesive coating weight may be between 2 and 100 gsm.

[0021] Thus, one exemplary embodiment relates to a composition, particularly a pressure-sensitive adhesive composition, such as a hot melt pressure-sensitive adhesive composition, comprising: a polyol ester; a styrene-isoprene-styrene block copolymer; a binder; and a naphthenic oil. Hot melt pressure-sensitive adhesives are often not used in high-performance applications because they typically perform poorly when subjected to high temperatures or other solvents. In addition, higher coat weight hot melt adhesives often suffer from bleed issues, which can cause problems during die-cutting or slitting. Therefore, the crosslinked rubber-based hot melt adhesives described herein address these limitations. All formulations are free of any mineral oil.

[0022] In yet other embodiments of the composition, there is provided a composition comprising: a styrene-isoprene-styrene block copolymer; a polybutylene polymer; and a tackifier.

[0023] The composition of exemplary embodiments may further include additives such as pigments, colors or colorants, fillers, diluents, antioxidants, UV absorbers, and the like, and combinations thereof, provided that their inclusion does not affect adhesive performance properties, label safety, and recyclability.

[0024] If desired, the pigment is provided in an amount sufficient to impart the desired color to the adhesive.Examples of pigments include, but are not limited to, solid inorganic fillers such as carbon black, titanium dioxide, and the like, and organic dyes.

[0025] Antioxidants may also be included in the composition. Cutting agents, such as waxes and surfactants, may also be included in the adhesive composition. Light stabilizers, heat stabilizers, and UV absorbers may also be included in the adhesive composition. Photoinitiators are included in exemplary embodiments. UV absorbers include benzotriazole derivatives, hydroxybenzylphenones, esters of benzoic acid, oxalic acid, diamides, and the like. Light stabilizers include hindered amine light stabilizers, and heat stabilizers include dithiocarbamate compositions, such as zinc dibutyldithiocarbamate.

[0026] In exemplary embodiments, the polyol ester is present in an amount between about 35% and about 50% by weight. The polyol ester may also be a tackifier. One such polyol ester contemplated by exemplary embodiments is a pentaerythritol-esterified resin. One such polyol ester of this nature is marketed under the name Dertoline PLS, a deodorized and highly stable pentaerythritol-esterified rosin, and is a tackifier resin produced and distributed by DRT SA, a company headquartered in Bordeaux, France.

[0027] In some exemplary embodiments, the styrene-isoprene-styrene block copolymer is between about 10% and about 40% by weight. One such styrene-isoprene-styrene block copolymer contemplated is a styrene-isoprene-styrene (SIS) block copolymer system that achieves heat-resistant, light-curable crosslinking to eliminate the trade-off between hot-melt SIS systems and solvent-based SIS rubber systems, sold as Zeon SL-177 by Nippon Zeon, headquartered in Tokyo, Japan.

[0028] In some exemplary embodiments, the binder is present at between about 0.1 wt% and about 2 wt%. One such binder contemplated is composed primarily of isotactic propylene repeat units with random ethylene distribution and is sold under the name Vistamaxx 6202 by ExxonMobil, headquartered in Irving, Texas, USA.

[0029] In some exemplary embodiments, the naphthenic oil is between about 10% and 25% by weight. One such naphthenic oil contemplated is a highly refined, high viscosity oil sold under the name Nyflex 223 by Nynas AB, headquartered in Stockholm, Sweden, and Primol 352 by ExxonMobil, headquartered in Irving, Texas, USA. In certain embodiments, the naphthenic oil can be replaced by a plasticizing oil. The plasticizing oil can be naphthenic oil, paraffinic mineral oil, or medicinal mineral oil.

[0030] In some exemplary embodiments, the antioxidant is present at between about 0.01 wt% and about 1.5 wt%. One such antioxidant contemplated is tetrakis[methylene-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate]methane and tris(2,4-di-tert-butylphenyl)phosphite (1:2), sold under the name Songnox® 21B by Songwon, headquartered in Ulsan, South Korea.

[0031] In some exemplary embodiments, additional block copolymers may be used. When used, the additional block copolymer is between about 10% and about 25% by weight. In some embodiments, this may be a linear random block styrene / butadiene copolymer having a styrene content of 25% and 17.5% as polystyrene blocks, sold under the name Solprene 1205 by Dynasol Elastomers, headquartered in Houston, Texas, USA. In other embodiments, the additional block copolymer may be a thermoplastic elastomer having a polystyrene-polyisoprene block structure of about 20% to about 35%, sold under the name Quintac 3270 by Nippon Zeon, headquartered in Tokyo, Japan. Other embodiments may provide a mixture of a linear random block styrene / butadiene copolymer having a styrene content of 25% and 17.5% as polystyrene blocks with a thermoplastic elastomer having a polystyrene-polyisoprene block structure of between about 20% and about 37%.

[0032] In some exemplary embodiments, the photoinitiator is present at between about 0.25% and about 5% by weight. One such photoinitiator contemplated by exemplary embodiments is 2-hydroxy-1-[4-[4-(2-hydroxy-2-methylpropionyl)benzyl]phenyl]-2-methylpropan-1-one, sold under the name Omnirad 127D by IGM Resin bv of Waalwijk, The Netherlands. Another such example of a photoinitiator contemplated by exemplary embodiments is a difunctional α-hydroxyketone, specifically 2-hydroxy-1-{4-[4-(2-hydroxy-2-methylpropionyl)phenoxy]phenyl}-2-methylpropan-1-one, also sold under the name Esacure KIP 160 by IGM Resin bv of Waalwijk, The Netherlands.

[0033] In some embodiments, the resulting hot melt pressure sensitive adhesive is crosslinked. As it crosslinks, free radicals are generated by the photoinitiator and the energy source. Specific embodiments use ultraviolet (UV) light, while other embodiments specifically use UV-C light with a wavelength between 100-280 nm. To achieve the desired amount of crosslinking, various photoinitiators can be used, and different doses of UV-C radiation can be used. In exemplary embodiments, 5 and 150 mJ / cm 2 However, the ultimate use of the radiation depends on the desired implementation of the resulting adhesive.

[0034] In some exemplary embodiments, the polybutene polymer is present in an amount between about 15% and about 25% by weight. Some exemplary polybutene polymers are liquid polybutene homopolymers supplied by INEOS Olefins & Polymers USA of League City, Texas, sold under the names Indopol H-100 and Indopol H-300. These polybutene polymers can be used alone or in combination.

[0035] In an exemplary embodiment, a separate tackifier may be used. The weight percentage of the tackifier may be between about 40% and about 55%. Two such contemplated tackifiers are the alicyclic hydrocarbon resin sold as Escorez 5300 and the aromatic modified aliphatic hydrocarbon resin with a narrow molecular weight distribution sold as Escorez 2203, both sold by ExxonMobil headquartered in Irving, Texas, USA. The tackifier containing the aromatic modified aliphatic hydrocarbon resin with a narrow molecular weight distribution has an average molecular weight (M) between about 1600 g / mol and 2800 g / mol. w ).

[0036] Release pad In some embodiments, the laminates described herein may include one or more release liners. The liner may have a first side, a second side opposite the first side, a first edge, and a second edge opposite the second edge. The liner may be any useful liner that provides the necessary support and isolation. The liner may be made from a variety of materials, including but not limited to paper or polymer film liners. In one embodiment, the paper has a caliper sufficient to allow die cutting of the resulting laminate or article. For example, for a PET liner, the liner thickness may range from approximately 18 mm to 23 mm. In one embodiment, the liner has a flatness. In some embodiments, the liner has a machine glaze or finish. In some embodiments, the liner has a silicone hold-out layer. The hold-out layer provides adhesion between the release coating and the release liner. The silicone hold-out layer also prevents the silicone release coating from penetrating into the liner.

[0037] In some embodiments, the release liner includes a liner having a release coating. The release coating of the release liner provides a releasable bond with the PSA or other adhesive. The release coating can be any composition that provides the desired releasable bond strength.

[0038] 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 control release agent. In some embodiments, the control release agent is of the formula R3SiO 1 / 2 The monofunctional silicone unit and the tetrafunctional silicone unit SiO 4 / 2 The copolymer of wherein R is an alkyl or alkenyl. In one embodiment, the alkyl or alkenyl comprises from about 1 to about 12 carbon atoms, or from about 1 to about 6 carbon atoms. Non-limiting examples of alkyl and alkenyl include methyl, ethyl, propyl, butyl, hexyl, vinyl, propenyl, butenyl and hexenyl.

[0039] The control release agent is generally reacted with a polysiloxane. The polysiloxane can be any polysiloxane used to form a release coating. Examples of useful polysiloxanes include, but are not limited to, vinyl-terminated, hydroxyl-terminated, and epoxy-terminated polysiloxanes. In one embodiment, the polysiloxane is a functional polydialkylsiloxane in which the alkyl group contains from about 1 to about 6 carbon atoms. The alkyl group independently includes, but is not limited to, methyl, ethyl, propyl, butyl, pentyl, hexyl, or a mixture thereof. In one embodiment, the alkyl or alkenyl group contains from 1 to about 12 carbon atoms, or from 1 to about 6 carbon atoms. The polysiloxane generally has a viscosity average molecular weight greater than 300,000 centipoise (cps). In another embodiment, the polysiloxane has a viscosity molecular weight of from about 300,000 to about 1,000,000 or more. The polysiloxane can be represented by formula (I): RO((Si(R)2O) x )—Si)—R (I) wherein each R is independently as defined above and x is an integer.

[0040] In some embodiments, the release coating is prepared using a crosslinking agent. In some embodiments, the crosslinking agent is a reactive polysiloxane, such as a polydialkyl or polyhydroalkyl siloxane. These alkyl groups are the same as those described above.

[0041] The barrier coating can be applied in solvent, solventless, or emulsion form. The barrier coating can be cured by any known curing process (e.g., heat, radiation, etc.) to form the barrier coating. Curing can be catalyzed by a silicone-soluble complex of a Group VIII transition metal (e.g., platinum).

[0042] Commercially available release agents include, but are not limited to, GE SS-4335, a silicone release agent in a non-reactive solvent. Commercially available polysiloxanes include, but are not limited to, GE SS-4331, a vinyl-terminated polydimethylsiloxane. Commercially available linkers include, but are not limited to, GE SS-4300C, a polymethylvinylsiloxane. Exemplary catalysts include, but are not limited to, SS-8010 catalyst in toluene. These materials are commercially available from the Silicone Products Division of General Electric Company. Similar silicone products are available from Dow Corning Corporation under the trade name Syl-off.

[0043] It should be understood that the present subject matter is not limited to any of the mentioned release coatings or release agents, but rather encompasses virtually any release coating or release agent suitable for the intended end use application. Furthermore, while the present subject matter has been described in conjunction with a release liner, it should be understood that appropriately configured carrier films and other components may be used in place of a release liner.

[0044] Surface material Suitable surface materials include, but are not limited to, synthetic papers such as polyolefin and polystyrene types; various plastic films or sheets such as polyolefins, polyvinyl chloride, polyethylene terephthalate, polystyrene, polyurethane, polymethacrylate, and polycarbonate. Other examples of suitable surface materials include paper and cardboard. The surface material may be or may include a multilayer polymer sheet. The multilayer may be coextruded, or the multilayer may be laminated together. In one embodiment, the surface material includes both coextruded multilayers and laminated multilayers. In addition, a white opaque film may be formed by adding a white pigment to one or more of the above-mentioned synthetic resins and used as the surface material. In one embodiment, a foam film is used as the surface material. The foam film may be formed by conventional foaming operations. In another embodiment, the surface material may be a laminate formed by combining a plurality of single-layer sheets composed of the materials listed above. Examples of such laminates may 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 surface material includes coated and uncoated paper, metallized paper, aluminum foil, laminated paper and paper with polymer material extruded on the paper surface. In some versions, the surface material can be coated with a liquid absorbent material. The selected surface material can be porous or semi-porous. The surface material can exhibit certain visibility characteristics, such as opacity, color and / or brightness. The surface material can include water or other liquid absorbency. The surface material can be conductive and / or include a conductive coating or area. Various commercially available surface materials can be used, such as, for example, those available under the name TESLIN.

[0045] The thickness of the surface material is optionally determined by reference to specific application standards. Such standards may 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 may be used on the surface material to increase the bond strength between the surface material and the dry topcoat composition to be formed on the surface of the surface material.

[0046] In certain embodiments described herein, the surface material exhibits one or more functions or functional properties. For example, the surface material can be selected to achieve or facilitate indication (e.g., visual indication of liquid), degassing (e.g., directing or allowing air or gas to flow through the thickness of the surface material), water or liquid retention within the surface material, electrical discharge or conductivity of the surface material, chemical transport through the thickness of the surface material, sound transmission through the thickness of the surface material, and / or combinations of these functions or properties.

[0047] Optional layer The adhesive-coated surface materials and / or laminates described herein may include one or more additional layers or components. Non-limiting examples of such layers include protective layers, tie coat layers, clear layers, color layers, white layers, reflective layers, fluid transfer layers, strength-promoting layers, top coats, print receptive layers, print containing layers, marking layers, functional layers, barrier coatings, and the like.

[0048] Laminate material properties The laminates described herein may have specific and useful properties or functionality. In some embodiments, the technology described herein can form a laminate in which the transfer, propagation, and / or migration of liquids, gases, sound waves, electrical currents, and / or other agents or elements can occur and be controlled across or through the laminate in the Z direction. References herein to the "Z direction" refer to the direction across the thickness dimension of the laminate or a portion thereof, and thus references to the "X direction" and / or "Y direction" refer to directions perpendicular to the Z direction and corresponding to the width and length dimensions of the laminate.

[0049] Non-limiting representative examples of laminates having certain functionalities provided by the present subject matter include liquid indicator laminates, degassing laminates, water absorbing laminates, sound channeling laminates, conductive laminates, and laminates having combinations of these functionalities and / or laminates having one or more of these functionalities in combination with additional functionalities.

[0050] For example, liquid-indicating laminates can be produced such that the speed of the indicator color change is linked to the facestock selection and the properties of the porous adhesive. Discontinuous structures, such as those created by pores in the adhesive layer or region(s), can allow, for example, liquids to transfer through the discontinuous adhesive from one side of the adhesive to the other and produce a permanent color change when a dye or other agent in the functional coating of the laminate is dissolved.

[0051] In one embodiment, a liquid-indicating laminate is provided. The speed or rate of the indicator color change is correlated to the facestock properties, such as, for example, liquid absorbency and the porosity of the patterned adhesive in the Z direction. The indication is generally irreversible and can be measured by color change or by simple visual comparison.

[0052] The discoloration of a surface layer or region of a laminate can be measured and quantified by optical changes (e.g., using CIE Lab or by simple visual comparison). The discoloration can be permanent or non-permanent. The discoloration can also be temporary, returning to its original state after a period of time. In some embodiments, this period of time is predetermined.

[0053] This phenomenon of transport through discontinuities in the adhesive in the Z direction can be implemented in other label applications, particularly pressure sensitive adhesive labels, such as, for example, labels for degassing a substrate, such as by air transport in the Z direction, labels for marking a damp substrate, such as by liquid transport in the Z direction, labels for electrical discharge in the Z direction, labels for chemical transport from one layer to another in the Z direction, and / or labels for acoustic transport in the Z direction. This phenomenon enables a medium or agent to pass through, transfer, and / or migrate from one side of an adhesive area of ​​a laminate to the other side of an adhesive area. Although reference to media penetration or transport is made in the Z direction, it should be understood that the subject matter is not limited thereto and may also include penetration / transport in the X direction and / or in the Y direction.

[0054] In some embodiments, the laminate as described herein includes a secondary adhesive layer or region. The secondary adhesive is generally used to attach the laminate to the substrate of interest. The secondary adhesive may comprise one or more adhesives identical or different with the adhesive of patterned or porous adhesive. This paper provides a description of a representative example of the secondary adhesive. In this adhesive configuration, the primary adhesive can be applied to the face material, the secondary adhesive can be applied to the release liner, and the adhesive applied and the release liner can be laminated together so that the primary adhesive and the secondary adhesive are in direct contact with each other. Alternatively or additionally, the primary adhesive and the secondary adhesive can all be applied to the face material or the release liner and then laminated together. Considering that the primary adhesive and the secondary adhesive can be face material, primary adhesive, secondary adhesive and release liner relative to the delamination of the face material and the release liner, or face material, secondary adhesive, primary adhesive, release liner. No matter how the order of the primary adhesive and the secondary adhesive is, considering that another adhesive can be continuous, it is envisioned that at least one of the primary adhesive and the secondary adhesive is patterned.

[0055] In some embodiments, a range of different arrangements of layers and components can be employed. In some embodiments using a patterned adhesive (e.g., a discontinuous adhesive layer), the layer is positioned between the functional facestock and the liner or functional layer. Alternatively, in liquid-indicating laminates, the patterned adhesive can be positioned between the functional facestock and the functional agent layer or region sensitive to liquids passing through the laminate. Furthermore, in liquid-indicating laminates, the functional agent layer or region can be positioned between the patterned adhesive and the carrier layer.

[0056] The techniques and features described herein enable the production of adhesive laminates and / or adhesive-coated skins having fluid / air management properties, controlled removability, and / or unique thermal and / or electrical conductivity. Furthermore, the use of these techniques and features enables the reduction of materials (e.g., adhesive), thereby enabling cost savings. However, it should be understood that the present subject matter encompasses the adhesive-coated skins and laminates described herein that are formed by methods other than those described herein.

[0057] Another embodiment relates to a laminate comprising: a face stock layer comprising paper; wherein the face stock layer has a first side and a second side; and an adhesive layer applied to at least a portion of the second side of the face stock layer, comprising a pressure adhesive composition as described herein. The face stock generally has a thickness ranging from 10 μm to 250 μm, preferably from 30 μm to 220 μm. The adhesive layer generally has a thickness ranging from 5 μm to at least 125 μm, preferably from 10 μm to at least 100 μm. In certain embodiments, the laminate further comprises a release layer on the adhesive layer on the side opposite to the face stock layer. In certain embodiments, the laminate further comprises a printed mark on the first side of the face stock layer.

[0058] In some embodiments, the face stock layer used in the laminate construction may be coated with one or more coatings. Generally, the coating is initially in a liquid or flowable state; is deposited or applied to an underlying backing film or other layer; and then cured or otherwise solidified. For applications where the coating forms a film, the film is generally independent of the underlying film or other layer. In many embodiments, the backing films described herein are free standing films. However, the films formed by the coatings described herein can be positioned next to or in conjunction with a backing film or other layer. The thickness or coating weight of the coating can be greater than 1 gsm and generally ranges from 1 gsm to 30 gsm. In certain embodiments, the thickness or coating weight of the coating ranges from 5 gsm to 30 gsm. However, it should be understood that the thickness or coating weight of the coating can be less than 1 gsm, and / or greater than 30 gsm.

[0059] The coatings used in the exemplary embodiments can be formed using a variety of techniques. When the composition is deposited on the surface of interest, the composition layer is dried, hardened, and / or otherwise cured to form a coating. After the composition is deposited and during or after the coating is formed, one or more post-deposition treatments, such as exposure to radiation or heat, can be employed. In some embodiments, the coating or film undergoes crosslinking during preparation or deposition.

[0060] The composition for laminate construction can form a single layer or comprise multiple layers of adhesive. Multiple layers of adhesive can be applied simultaneously to the film or laminate using methods known in the art. Examples of suitable adhesive coating methods include slot die coating, bullnose coating, reverse roll coating, and the like.

[0061] The release layer useful in the laminated construction of the present invention may comprise any of a variety of materials known to those skilled in the art to be suitable as release liners. In one embodiment, the release liner comprises or is a 90# ​​stayflat liner. As is known in the art, other suitable release liners include silicone-coated films or polycoated kraft paper. Suitable pre-siliconized release liners are commercially available. Release liners may be flat or structured.

[0062] Topcoat formulation and application In the exemplary embodiments discussed herein, the topcoat is deposited on the substrate by any suitable method. In embodiments, suitable methods include any suitable coating techniques. Embodiments include depositing the coating on the substrate by any suitable liquid deposition method. Without limitation, examples of suitable methods include bath coating, spray coating, slit coating, spin coating, curtain coating, gravure coating, reverse gravure print coating, reverse roll coating, roller blade (i.e., gap) coating, metering (Meyer) rod coating, air knife coating, or any combination thereof. Bath coating includes immersion or dipping in an aqueous solution. In one embodiment, the coating is deposited by a bath in an aqueous solution. In other embodiments, the coating is deposited by spraying an aqueous solution.

[0063] Methods and exemplary configurations After discussing the various components of the compositions, exemplary methods and methodologies of operation will be discussed.

[0064] Figure 1 1 shows a laminate construction as described herein. As described herein (and not shown to scale), laminate construction 100 includes a facestock layer 10, a pressure-sensitive adhesive layer 20, and an optional release layer 30. Facestock layer 10 defines a first side 12 and an oppositely oriented second side 14. The facestock layer is shown as a single layer, but multiple layers are possible. Pressure-sensitive adhesive layer 20 is applied to at least a portion of second side 14. The pressure-sensitive adhesive layer is shown as a single layer, but multiple layers are possible.

[0065] Figure 2 A laminate construction as described herein is shown. As described herein (and not shown to scale), laminate construction 200 includes a facestock layer 10 (e.g., paper), a pressure-sensitive adhesive layer 20, an optional release layer 30, optional printed indicia 40 (e.g., turbo, latex, UV, or eco-sol ink), an optional coating 50, and an optional transfer tape 60 (e.g., a paper transfer tape). Facestock layer 10 defines a first side 12 and an oppositely oriented second side 14. The backing film is shown as a single layer, but multiple layers are possible. Pressure-sensitive adhesive layer 20 is applied to at least a portion of second side 14. The pressure-sensitive adhesive layer is shown as a single layer, but multiple layers are possible.

[0066] Example Prepare hot melt pressure sensitive adhesive formulations with the composition shown in the following examples.All percentages are given in weight percentages.Each of these is a curable composition when subjected to UV light, which will activate the photoinitiator and subsequently promote crosslinking in the cured product.These can be formulated and cured on substrates, or can be cured before being applied to the desired substrate, as will be appreciated, depending on the desired implementation of the various substrates.

[0067] Series A - Examples 1-4 Recycled Compatible Adhesives Example 1 Example 1 was prepared using 42.9% of polyol ester, 21.1% of styrene-isoprene-styrene block copolymer, 17.2% of naphthenic oil, 15.5% of thermoplastic elastomer having a polystyrene-polyisoprene block structure, 1.9% of photoinitiator, 1% of binder, and 0.6% of antioxidant.

[0068] Example 2 Example 2 was prepared using 42.9% polyol ester, 21.1% linear random block styrene / butadiene copolymer having a styrene content of 25% (17.5% as polystyrene blocks), 17.2% naphthenic oil, 15.5% styrene-isoprene-styrene block copolymer, 1.9% photoinitiator, 1% binder, and 0.6% antioxidant.

[0069] Example 3 Example 3 was prepared using 42.9% of polyol ester, 21.1% of styrene-isoprene-styrene block copolymer, 17.2% of naphthenic oil, 15.5% of thermoplastic elastomer having a polystyrene-polyisoprene block structure, 1.9% of photoinitiator, 1% of binder, and 0.6% of antioxidant.

[0070] Example 4 Example 4 was prepared using 42.9% polyol ester, 36.6% styrene-isoprene-styrene block copolymer, 17.2% naphthenic oil, 1.9% photoinitiator, 1% binder, and 0.6% antioxidant.

[0071] Series B - Solvent Replacement Adhesives - Examples 5-28 Example 5 Example 5 was prepared using 35% of a tackifier in the form of a compound comprising an alicyclic hydrocarbon resin, 27% of a styrene-isoprene-styrene block copolymer, 35% of a polybutylene polymer, 1.3% of a photoinitiator, and 0.7% of an antioxidant.

[0072] Example 6 Example 6 was prepared using 35% of a tackifier in the form of a compound comprising an alicyclic hydrocarbon resin, 35% of a styrene-isoprene-styrene block copolymer, 27% of a polybutylene polymer, 1.3% of a photoinitiator, and 0.7% of an antioxidant.

[0073] Example 7 Example 7 was prepared using 39% of a tackifier in the form of a compound comprising an alicyclic hydrocarbon resin, 27% of a styrene-isoprene-styrene block copolymer, 31% of a polybutylene polymer, 1.3% of a photoinitiator, and 0.7% of an antioxidant.

[0074] Example 8 Example 8 was prepared using 39% of a tackifier in the form of a compound comprising an alicyclic hydrocarbon resin, 27% of a styrene-isoprene-styrene block copolymer, 31% of a polybutylene polymer, 1.3% of a photoinitiator, and 0.7% of an antioxidant.

[0075] Example 9 Example 9 was prepared using 42% of a tackifier in the form of a compound comprising an alicyclic hydrocarbon resin, 20% of a styrene-isoprene-styrene block copolymer, 35% of a polybutylene polymer, 1.3% of a photoinitiator, and 0.7% of an antioxidant.

[0076] Example 10 Example 10 was prepared using 42% of a tackifier in the form of a compound comprising an alicyclic hydrocarbon resin, 35% of a styrene-isoprene-styrene block copolymer, 20% of a polybutylene polymer, 1.3% of a photoinitiator, and 0.7% of an antioxidant.

[0077] Example 11 Example 11 was prepared using 42% of a tackifier in the form of a compound comprising a cycloaliphatic hydrocarbon resin, 24% of a styrene-isoprene-styrene block copolymer, 31% of a polybutylene polymer, 1.3% of a photoinitiator, and 0.7% of an antioxidant.

[0078] Example 12 Example 12 was prepared using 42% of a tackifier in the form of a compound comprising an alicyclic hydrocarbon resin, 31% of a styrene-isoprene-styrene block copolymer, 24% of a polybutylene polymer, 1.3% of a photoinitiator, and 0.7% of an antioxidant.

[0079] Example 13 Example 13 was prepared using 42% of a tackifier in the form of a compound comprising an alicyclic hydrocarbon resin, 27% of a styrene-isoprene-styrene block copolymer, 27% of a polybutylene polymer, 1.3% of a photoinitiator, and 0.7% of an antioxidant.

[0080] Example 14 Example 14 was prepared using 50% of a tackifier in the form of a compound comprising an alicyclic hydrocarbon resin, 24% of a styrene-isoprene-styrene block copolymer, 24% of a polybutylene polymer, 1.3% of a photoinitiator, and 0.7% of an antioxidant.

[0081] Example 15 Example 15 was prepared using 57% of a tackifier in the form of a compound comprising an alicyclic hydrocarbon resin, 20% of a styrene-isoprene-styrene block copolymer, 20% of a polybutylene polymer, 1.3% of a photoinitiator, and 0.7% of an antioxidant.

[0082] Example 16 Example 16 was prepared using 35% of a tackifier in the form of a compound including an alicyclic hydrocarbon resin, 27% of a thermoplastic elastomer having a polystyrene-polyisoprene block structure, 35% of a polybutylene polymer, 1.3% of a photoinitiator, and 0.7% of an antioxidant.

[0083] Example 17 Example 17 was prepared using 35% of a tackifier in the form of a compound including an alicyclic hydrocarbon resin, 35% of a thermoplastic elastomer having a polystyrene-polyisoprene block structure, 27% of a polybutylene polymer, 1.3% of a photoinitiator, and 0.7% of an antioxidant.

[0084] Example 18 Example 18 was prepared using 39% of a tackifier in the form of a compound including an alicyclic hydrocarbon resin, 27% of a thermoplastic elastomer having a polystyrene-polyisoprene block structure, 31% of a polybutylene polymer, 1.3% of a photoinitiator, and 0.7% of an antioxidant.

[0085] Example 19 Example 19 was prepared using 39% of a tackifier in the form of a compound including an alicyclic hydrocarbon resin, 27% of a thermoplastic elastomer having a polystyrene-polyisoprene block structure, 31% of a polybutylene polymer, 1.3% of a photoinitiator, and 0.7% of an antioxidant.

[0086] Example 20 Example 20 was prepared using 42% of a tackifier in the form of a compound including an alicyclic hydrocarbon resin, 20% of a thermoplastic elastomer having a polystyrene-polyisoprene block structure, 35% of a polybutylene polymer, 1.3% of a photoinitiator, and 0.7% of an antioxidant.

[0087] Example 21 Example 21 was prepared using 42% of a tackifier in the form of a compound including an alicyclic hydrocarbon resin, 35% of a thermoplastic elastomer having a polystyrene-polyisoprene block structure, 20% of a polybutylene polymer, 1.3% of a photoinitiator, and 0.7% of an antioxidant.

[0088] Example 22 Example 22 was prepared using 42% of a tackifier in the form of a compound including an alicyclic hydrocarbon resin, 24% of a thermoplastic elastomer having a polystyrene-polyisoprene block structure, 31% of a polybutylene polymer, 1.3% of a photoinitiator, and 0.7% of an antioxidant.

[0089] Example 23 Example 23 was prepared using 42% of a tackifier in the form of a compound including an alicyclic hydrocarbon resin, 31% of a thermoplastic elastomer having a polystyrene-polyisoprene block structure, 24% of a polybutylene polymer, 1.3% of a photoinitiator, and 0.7% of an antioxidant.

[0090] Example 24 Example 24 was prepared using 42% of a tackifier in the form of a compound including an alicyclic hydrocarbon resin, 27% of a thermoplastic elastomer having a polystyrene-polyisoprene block structure, 27% of a polybutylene polymer, 1.3% of a photoinitiator, and 0.7% of an antioxidant.

[0091] Example 25 Example 25 was prepared using 50% of a tackifier in the form of a compound including an alicyclic hydrocarbon resin, 24% of a thermoplastic elastomer having a polystyrene-polyisoprene block structure, 24% of a polybutylene polymer, 1.3% of a photoinitiator, and 0.7% of an antioxidant.

[0092] Example 26 Example 26 was prepared using 57% of a tackifier in the form of a compound including an alicyclic hydrocarbon resin, 20% of a thermoplastic elastomer having a polystyrene-polyisoprene block structure, 20% of a polybutylene polymer, 1.3% of a photoinitiator, and 0.7% of an antioxidant.

[0093] Example 27 Example 27 was prepared using 46.5% of a tackifier in the form of a compound comprising a cycloaliphatic hydrocarbon resin, 32.1% of a styrene-isoprene-styrene block copolymer, 18.8% of a polybutylene polymer, 1.9% of a photoinitiator, and 0.7% of an antioxidant.

[0094] Example 28 Example 28 was prepared using 46.8% of a tackifier in the form of a compound including an alicyclic hydrocarbon resin, 32.3% of a thermoplastic elastomer having a polystyrene-polyisoprene block structure, 18.9% of a polybutylene polymer, 1.3% of a photoinitiator, and 0.7% of an antioxidant.

[0095] All definitions, as defined and used herein, should be understood to control over dictionary definitions, definitions in documents incorporated by reference, and / or ordinary meanings of the defined terms.

[0096] Unless expressly stated to the contrary, the articles "a" and "an" as used in the specification and claims should be understood to mean "at least one." The phrase "and / or," as used herein in the specification and claims, should be understood to mean "one or both" of the elements so conjoined, i.e., in some cases present conjoined and in other cases present separately. Multiple elements listed with "and / or" should be interpreted in the same manner, i.e., as "one or more" of the elements so conjoined. In addition to the elements specifically identified by the "and / or" clause, other elements may optionally be present, whether or not related to those specifically identified. Thus, as a non-limiting example, in one embodiment, when used in conjunction with an open-ended term such as "comprising," a reference to "A and / or B" may refer to only A (optionally including elements other than B); in another embodiment, only B (optionally including elements other than A); in yet another embodiment, both A and B (optionally including other elements); and so on. As used in the specification and claims, "or" should be understood to have the same meaning as "and / or" as defined above. For example, when separating items in an enumeration, "or" or "and / or" should be interpreted as inclusive, i.e., including at least one of a plurality or series of elements, but also including more than one, and optionally additional unenumerated items. Only terms that clearly indicate 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 or series of elements. In general, the term "or," as used herein, should only be interpreted as indicating exclusive alternatives (i.e., "one or the other but not both") when preceded by an exclusive term, such as "either of," "one of...", "only one of...", or "exactly one of...". When used in a claim, "consisting essentially of..." should have its ordinary meaning as used in the art of patent law.

[0097] As used in the specification and claims, with respect to a list of one or more elements, the phrase "at least one" should be understood to mean at least one element selected from any one or more elements in the list of elements, but does not necessarily include at least one of each element specifically listed in the list of elements and does not exclude any combination of elements in the list of elements. This definition also allows for the optional presence of elements in addition to the elements specifically identified in the list of elements to which the phrase "at least one" refers, whether or not related to those specifically identified elements. 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") may refer, in one embodiment, to at least one (optionally including more than one) of A, with B absent (and optionally including elements in addition to B); in another embodiment, to at least one (optionally including more than one) of B, with A absent (and optionally including elements in addition to A); in yet another embodiment, to at least one (optionally including more than one) of A and at least one (optionally including more than one) of B (and optionally including other elements); and so on.

[0098] An embodiment is an implementation or example of the present disclosure. References in the specification to "an embodiment," "one embodiment," "some embodiments," "a specific embodiment," or "other embodiments" mean that the specific features, structures, or characteristics described in connection with the embodiment are included in at least some embodiments of the present disclosure, but not necessarily in all embodiments of the present disclosure. The various appearances of "an embodiment," "one embodiment," "some embodiments," "a specific embodiment," or "other embodiments," or similar expressions, do not necessarily refer to the same embodiment(s).

[0099] If the specification states that a component, feature, structure, or characteristic "may," "might," or "could" be included, this does not require that specific component, feature, structure, or characteristic be included. If the specification or claims refer to "a" or "an" element, this does not mean that there is only that element. If the specification or claims refer to "an additional" element, this does not preclude the presence of more than one of the additional element.

[0100] As used herein in the specification and claims, including in the examples, and unless otherwise expressly stated, all numbers may be understood to begin with the word "about" or "approximately," even if the term does not explicitly appear. When describing a value and / or position, the phrase "about" or "approximately" may be used to indicate that the value and / or position described is within a reasonably expected range of values ​​and / or positions. For example, a numerical value may be + / -0.% (or a range of values) of the stated value, + / -1% (or a range of values) of the stated value, + / -2% (or a range of values) of the stated value, + / -5% (or a range of values) of the stated value, + / -10% (or a range of values) of the stated value, and so on. Any numerical range recited herein is intended to include all subranges subsumed therein.

[0101] In addition, any method of performing the present disclosure may occur in an order different from that described herein. Therefore, unless explicitly stated, the order of the method should not be understood as limiting. It should be appreciated that some of the steps of the method can be performed in a different order to achieve similar results.

[0102] In the claims and the preceding description, all transitional phrases such as "comprises," "comprising," "carrying," "having," "containing," "involving," "maintaining," "consisting of," etc., are to be construed as open-ended, i.e., meaning including but not limited to. Only the transitional phrases "consisting of" and "consisting essentially of" shall be closed or semi-closed transitional phrases, respectively, as set forth in the U.S. Patent Office Manual of Patent Examining Procedure.

[0103] In the foregoing description, certain terms have been used for brevity, clarity, and understanding. No unnecessary limitations are to be implied therefrom, except as required by the prior art, as these terms are used for descriptive purposes and are intended to be broadly interpreted.

[0104] Moreover, the descriptions and illustrations of the various embodiments of the disclosure are by way of example only and the disclosure is not limited to the exact details shown or described.

Claims

1. A composition comprising: Polyol esters; Styrene-isoprene-styrene block copolymer; Adhesive; naphthenic oil; and Photoinitiator.

2. The composition of claim 1, wherein the photoinitiator is present in the composition at about 1.8 wt % based on the weight of the composition.

3. The composition according to claim 1 or 2, further comprising: A block copolymer having: a styrene content of 25% by weight and 17.5% by weight polystyrene; and butadiene.

4. The composition according to claim 1, further comprising: Elastomer with a polystyrene-polyisoprene block structure.

5. The composition according to claim 1 or 4, wherein the polyol ester is pentaerythritol-esterified rosin.

6. The composition of claim 1 wherein the binder comprises isotactic propylene repeat units having random ethylene distribution.

7. The composition according to claim 1, wherein The percentage of the polyol ester is between about 35% and about 60% by weight; The percentage of the styrene-isoprene-styrene block copolymer is between about 15% and about 40% by weight; and The percentage of naphthenic oil is between about 10 wt % and about 25 wt %.

8. A laminate comprising: Surface material layer; wherein the face material layer has a first side and a second side; An adhesive layer comprising the composition of any preceding claim, after curing, is applied to at least a portion of the second side of the facestock layer.

9. The composition of claim 1, wherein the photoinitiator is present in the composition at about 1.9 wt % based on the weight of the composition.

10. A composition comprising: Styrene-isoprene-styrene block copolymer; polybutene polymers; Photoinitiator; and Thickener.

11. The composition of claim 10, wherein the tackifier comprises an alicyclic hydrocarbon resin.

12. The composition according to claim 10 or 11, wherein: The percentage of the styrene-isoprene-styrene block copolymer is between about 15% and about 40% by weight; The percentage of the polybutene polymer is between about 15% and about 40% by weight; and The percentage of the tackifier is between about 30 wt % and about 60 wt %.

13. A laminate comprising: Surface material layer; wherein the face material layer has a first side and a second side; An adhesive layer comprising the cured composition of claim 11 or claim 12 is applied to at least a portion of the second side of the facestock layer.

14. The composition according to any one of claims 10-13, wherein the average molecular weight (M) of the tackifier w ) is between about 1600 g / mol and 2800 g / mol.

15. The composition of claim 10, wherein the photoinitiator is present in the composition at about 1.3 wt. % based on the weight of the composition.

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