WO2020023474A1

WO2020023474A1 - Coated, metallized, conformable films

Info

Publication number: WO2020023474A1
Application number: PCT/US2019/042976
Authority: WO
Inventors: Anand Sundararaman; Marie-Luce DECOUX
Original assignee: Jindal Films Americas Llc
Priority date: 2018-07-25
Filing date: 2019-07-23
Publication date: 2020-01-30

Abstract

Disclosed are compositions and methods for conformable, metallized films, which may include a core layer consisting essentially of > 50 wt.% isotactic polypropylene, < 50 wt.% propylene-a-copolymer(s), and optionally additives. Further, this film may include a first skin layer and a second skin layer on opposing sides of the core layer, wherein the first skin layer and second skin layer consist essentially of: (i) medium-density polyethylene polymers or (ii) propyl-butylene polymers, ethyl-propyl-butylene polymers, or combinations thereof, and (iii) optionally additives. Further still, this film may include a metallized layer on one side of the first skin layer, wherein the one side of each of the first skin layer and the second skin layer faces away from the core layer, wherein the metallized layer has an optical density > 1.8. And, this film may include primer layer comprising about 50 wt % or more of acrylic-based, polyethylene-imine-based or polyurethane-based polymers.

Description

COATED, METALLIZED, CONFORMABLE FILMS

REFERENCE TO RELATED APPLICATIONS

[0001] This application is a Patent Cooperation Treaty application, which claims priority to United States provisional patent application serial number 62/702,977 filed on 25 July 2018 that is hereby incorporated by this reference in its entirety.

FIELD

[0002] This application relates to coated, metallized, conformable films that may have an oriented base film that is metallized and contains one or more coatings with excellent appearance and barrier properties in packaging and labelling applications.

BACKGROUND

[0003] Conformable metallized films are typically based on polyethylene (“PE”) films that are usually transfer-metallized as opposed to, for example, deposit-metallized. Such transfer metallization process is quite expensive due to the metal-transfer process from a metallized film to the PE film. This metal-transfer process also results in significant loss of material and costs because metal transfer is incomplete, and that means the non-transferred metal is discarded as waste. Additionally, such transfer-metallized PE films have poor barrier properties so as to permit migration of lower oligomers present in the masterbatch of the plastic containers. The migration of such oligomers can result in bubbling on the films’ surface and over-aging so as to result in a poor appearance.

[0004] With an aim at countermanding incumbent deficiencies, the present invention relates to a conformable metallic film that may have a print-receptive coating on the metal side that results in minimal to no change in the metal appearance, gloss, distinctness of image (DOI) and also provides enhanced printability and durability. Further, the back side of the metal may have an additional adhesive -receptive coating. The adhesive-receptive coating provides anchorage to pressure-sensitive adhesives for application onto substrates. Further still, the two- side-applied coatings show remarkable block resistance.

SUMMARY

[0005] Disclosed are compositions and methods for conformable, metallized films. In one example embodiment, the conformable, metallized film may include a core layer consisting essentially of > 50 wt.% isotactic polypropylene, < 50 wt.% propylene-a-copolymer(s), and optionally additives. Further, the conformable, metallized film may include a first skin layer and a second skin layer on opposing sides of the core layer, wherein the first skin layer and second skin layer consist essentially of: (i) medium-density polyethylene polymers or (ii) propyl-butylene polymers, ethyl-propyl-butylene polymers, or combinations thereof, and (iii) optionally additives. Further still, the conformable, metallized film may include a metallized layer on one side of the first skin layer, wherein the one side of each of the first skin layer and the second skin layer faces away from the core layer, wherein the metallized layer has an optical density > 1.8. And yet further, the conformable, metallized film may include a primer layer comprising about 50 wt % or more of acrylic-based, polyethylene-imine -based or polyurethane -based polymers.

BRIEF DESCRIPTION OF THE DRAWINGS

[0006] So that the manner in which the above recited features, advantages and objects of this disclosure are attained and may be understood in detail, a more particular description, briefly summarized above, may be had by reference to the embodiments thereof which are illustrated in the appended drawings.

[0007] It is to be noted, however, that the appended drawings illustrate only typical embodiments of this disclosure and are therefore not to be considered limiting of its scope, for the disclosure may admit to other equally effective embodiments.

[0008] FIG. 1 depicts UV-ink adhesion test results performed on samples 1-8 shown in Table 1 in accordance with the disclosed methods, structures, and compositions.

[0009] FIG. 2 depicts adhesive adhesion test results based on FINAT FTM1 low speed peeling 180 degree - 9th edition 2014 UK for Samples 4-7 from Table 1 in accordance with the disclosed methods, structures, and compositions.

[0010] FIG. 3 depicts blocking performance results based on ITM90 based on ASTM D3354-08 blocking load plastic film parallel plate method 201004 of samples 1-8 from Table 1 in accordance with the disclosed methods, structures, and compositions.

[0011] FIG. 4 depicts different, scaled, metal-side-coated samples based on the structure 10 shown in Table 2 in accordance with the disclosed methods, structures, and compositions.

[0012] FIGS. 5A-5D report on scratch resistance test results with a black nylon brush for samples 9-24 in Table 3 in accordance with the disclosed methods, structures, and compositions. [0013] FIGS. 6A-6D report on scratch resistance test results with a boar fur brush for samples 9-24 in Table 3 in accordance with the disclosed methods, structures, and compositions.

[0014] FIG. 7 depicts a ranking by metal resistance scale of sample films in accordance with the disclosed methods, structures, and compositions.

[0015] FIG. 8 depicts distinctiveness-of-image data for two different metallized base films based on structures 5 and 6, prior to coating these films with print-receptive coating in accordance with the disclosed methods, structures, and compositions.

[0016] FIG. 9 depicts the percentage reflectance measured using Elcometer 408 Gloss and a DOI Meter on the metallized side of structures 5 and 6 in accordance with the disclosed methods, structures, and compositions.

DETAILED DESCRIPTION

[0017] Below, directional terms, such as“above,”“below,”“upper,”“lower,”“front,” “back,”“top,”“bottom,” etc., are used for convenience in referring to the accompanying drawings. In general,“above,”“upper,”“upward,”“top,” and similar terms refer to a direction away the earth’ s surface, and“below,”“lower,”“downward,”“bottom,” and similar terms refer to a direction toward the earth’ s surface, but is meant for illustrative purposes only, and the terms are not meant to limit the disclosure.

[0018] Various specific embodiments, versions and examples are described now, including exemplary embodiments and definitions that are adopted herein for purposes of understanding. While the following detailed description gives specific preferred embodiments, those skilled in the art will appreciate that these embodiments are exemplary only, and that the disclosure can be practiced in other ways. For purposes of determining infringement, the scope of the invention will refer to the any claims, including their equivalents, and elements or limitations that are equivalent to those that are recited.

[0019] As used herein,“polymer” may be used to refer to homopolymers, copolymers, interpolymers, terpolymers, etc. Likewise, a“copolymer” may refer to a polymer comprising two monomers or to a polymer comprising three (/._<?., terpolymer) or more monomers.

[0020] As used herein, “intermediate” is defined as the position of one layer of a multilayered film, wherein said layer lies between two other identified layers. In some embodiments, the intermediate layer may be in direct contact with either or both of the two identified layers. In other embodiments, additional layers may also be present between the intermediate layer and either or both of the two identified layers. [0021] As used herein,“elastomer” is defined as a propylene-based or ethylene-based copolymer that can be extended or stretched with force to at least 100% of its original length, and upon removal of the force, rapidly (e.g., within 5 seconds) returns to its original dimensions.

[0022] As used herein,“plastomer” is defined as a propylene-based or ethylene-based copolymer having a density in the range of 0.850 g/cm³ to 0.920 g/cm³ and a DSC melting point of at least 40°C.

[0023] As used herein,“about” before a range or number means ± 5% within that range or number. For example, in a range from about 5 to 10%, this equates to 4.9% to 10.2%.

[0024] As used herein,“substantially free” is defined to mean that the referenced film layer is largely, but not wholly, absent a particular component. In some embodiments, small amounts of the component may be present within the referenced layer as a result of standard manufacturing methods, including recycling of film scraps and edge trim during processing.

[0025] Generally disclosed are metallized biaxially oriented polypropylene (“BOPP”) films, which provide excellent appearance and barrier properties in packaging and labelling applications. For instance, the metallic appearance in label applications provides product distinction because of their mirror-like appearance. Additionally, conformability of metallized labels may adopt the contour of a container, e.g., shampoo, liquid soaps, detergents, etc. so as to result in a useful and unique appearance that results in product differentiation. Such conformable labels may withstand several squeezability cycles with minimal damage to the appearance of the film. And, initial printability and print quality of conformable labels is maintained through several squeezing cycles.

Core Layer

[0026] As is known to those skilled in the art, the core layer of a multilayered film is most commonly the thickest layer and provides the foundation of the multilayered structure. In embodiments, the core layer may comprise or consist essentially of monoaxially oriented polypropylene (“MOPP”) or biaxially oriented polypropylene (“BOPP”), biaxially oriented polyethylene (BOPE) wherein the relative stereochemistry is isostatic, otherwise, or combinations thereof. Further, the core layer also comprises equal or lesser amounts, e.g., 5, 10, 15, 20, 25, 30, 35, 40, 45 or 50 weight percent, of additional polymer(s) in order to make the core layer conformable. Examples of additional polymer(s) are selected from the group consisting of propylene- a-copolymers, ethylene -propylene copolymers, ethylene-propylene- butene terpolymers, cyclic olefin copolymers, polyurethanes, polyvinylchlorides, polyethylenes, acrylic resins, ethylene-acrylic acid resins, polytetrafluoroethylene polymers, elastomers, and combinations thereof. For example, one polymer may be a grade of VISTAMAXX™ polymer (commercially available from ExxonMobil Chemical Company of Baytown, Tex.), such as VM6100 and VM3000 grades. Alternatively, suitable polymers may include VERSIFY™ polymer (commercially available from The Dow Chemical Company of Midland, Mich.), PB (propylene-butene- 1) random copolymers, such as Basell PB 8340 (commercially available from Basell Polyolefins of The Netherlands), Borealis BORSOFT™ SD233CF, (commercially available from Borealis of Denmark), EXCEED™ 1012CA and 1018CA metallocene polyethylenes, EXACT™ 5361, 4049, 5371, 8201, 4150, 3132 polyethylene plastomers, EMCC 3022.32 low density polyethylene (LDPE) (commercially available from ExxonMobil Chemical Company of Baytown, Tex.).

[0027] The core layer may further include a hydrocarbon resin. Hydrocarbon resins may serve to enhance or modify the flexural modulus, improve processability, or improve the barrier properties of the film. The resin may be a low molecular weight hydrocarbon that is compatible with the core polymer. Optionally, the resin may be hydrogenated. The resin may have a number average molecular weight less than 5000, preferably less than 2000, most preferably in the range of from 500 to 1000. The resin can be natural or synthetic and may have a softening point in the range of from 60°C to l80°C.

[0028] Suitable hydrocarbon resins include, but are not limited to petroleum resins, terpene resins, styrene resins, and cyclopentadiene resins. In some embodiments, the hydrocarbon resin is selected from the group consisting of aliphatic hydrocarbon resins, hydrogenated aliphatic hydrocarbon resins, aliphatic/aromatic hydrocarbon resins, hydrogenated aliphatic aromatic hydrocarbon resins, cycloaliphatic hydrocarbon resins, hydrogenated cycloaliphatic resins, cycloaliphatic/aromatic hydrocarbon resins, hydrogenated cycloaliphatic/aromatic hydrocarbon resins, hydrogenated aromatic hydrocarbon resins, polyterpene resins, terpene- phenol resins, rosins and rosin esters, hydrogenated rosins and rosin esters, and combinations thereof.

[0029] The amount of such hydrocarbon resins, either alone or in combination, in the core layer is preferably less than 20 wt %, more preferably in the range of from 1 wt % to 5 wt %, based on the total weight of the core layer.

[0030] The core layer may further comprise one or more additives such as opacifying agents, pigments, colorants, cavitating agents, slip agents, antioxidants, anti-fog agents, anti static agents, fillers, moisture barrier additives, gas barrier additives, and combinations thereof, as discussed in further detail below. A suitable anti-static agent is ARMOSTAT™ 475 (commercially available from Akzo Nobel of Chicago, Ill.).

[0031] Cavitating agents may be present in the core layer, or any other layer(s) in the disclosed film, in an amount less than 30 wt %, preferably less than 20 wt %, most preferably in the range of from 2 wt % to 10 wt %, based on the total weight of the layer.

[0032] The core layer preferably has a thickness in the range of from about 5 pm to 100 pm, more preferably from about 5 pm to 50 pm, most preferably from 5 pm to 25 pm.

Tie Layer(s)

[0033] Tie layer(s) of a multilayered film is typically used to connect two other layers of the multilayered film structure, e.g. , a core layer and a skin layer, and is positioned intermediate these other layers. The tie layer(s) may have the same or a different composition as compared to the core layer.

[0034] In some embodiments, the tie layer is in direct contact with the surface of the core layer. In other embodiments, another layer or layers may be intermediate the core layer and the tie layer. The tie layer may comprise one or more polymers. In addition, the polymers may include C₂ polymers, maleic-anhydride-modified polyethylene polymers, C₃ polymers, C2C3 random copolymers, C2C3C4 random terpolymers, heterophasic random copolymers, C₄ homopolymers, C₄ copolymers, metallocene polymers, propylene-based or ethylene-based elastomers and/or plastomers, ethyl-methyl acrylate (EMA) polymers, ethylene-vinyl acetate (EVA) polymers, polar copolymers, and combinations thereof. For example, one polymer may be a grade of VISTAMAXX™ polymer (commercially available from ExxonMobil Chemical Company of Baytown, Tex.), such as VM6100 and VM3000 grades. Alternatively, suitable polymers may include VERSIFY™ polymer (commercially available from The Dow Chemical Company of Midland, Mich.), Basell CATALLOY™ resins such as ADFLEX™ T100F, SOFTELL™ Q020F, CLYRELL™ SM1340 (commercially available from Basell Polyolefins of The Netherlands), PB (propylene-butene-l) random copolymers, such as Basell PB 8340 (commercially available from Basell Polyolefins of The Netherlands), Borealis BORSOFT™ SD233CF, (commercially available from Borealis of Denmark), EXCEED™ 1012CA and 1018CA metallocene polyethylenes, EXACT™ 5361, 4049, 5371, 8201, 4150, 3132 polyethylene plastomers, EMCC 3022.32 low density polyethylene (LDPE) (commercially available from ExxonMobil Chemical Company of Baytown, Tex.).

[0035] In some embodiments, the tie layer may further comprise one or more additives such as opacifying agents, pigments, colorants, cavitating agents, slip agents, antioxidants, anti-fog agents, anti-static agents, anti-block agents, fillers, moisture barrier additives, gas barrier additives, and combinations thereof, as discussed in further detail below.

[0036] The thickness of the tie layer is typically in the range of from about 0.50 to 25 pm, preferably from about 0.50 pm to 12 pm, more preferably from about 0.50 pm to 6 pm, and most preferably from about 2.5 pm to 5 pm. However, in some thinner films, the tie layer thickness may be from about 0.5 pm to 4 pm, or from about 0.5 pm to 2 pm, or from about 0.5 pm to 1.5 pm.

Skin Layer(s), Including Metallizable Skin Layers

[0037] In some embodiments, the skin layer comprises at least one polymer selected from the group comprising, consisting essentially of, and/or consisting of one or more polypropylene copolymers, low-density polyethylenes, medium-density polyethylenes, cyclic olefin copolymers, polyurethanes, polyvinylchlorides, polyethylenes, acrylic resins, ethylene- acrylic acid resins, polytetrafluoroethylene polymers, elastomers, and combinations thereof .

[0038] The skin layer may also comprise processing aid additives, such as anti-block agents, anti-static agents, slip agents and combinations thereof, as discussed in further detail below.

[0039] The thickness of the skin layer depends upon the intended function of the skin layer, but is typically in the range of from about 0.20 pm through 3.5 pm, or from 0.30 pm through 2 pm, or in many embodiments, from 0.50 pm through 1.0 pm. In thin film embodiments, the skin layer thickness may range from about 0.20 pm through 1.5 pm, or 0.50 pm through 1.0 pm.

Additives

[0040] Additives present in the film’s layer(s) may include, but are not limited to opacifying agents, pigments, colorants, cavitating agents, slip agents, antioxidants, anti-fog agents, anti-static agents, anti-block agents, fillers, moisture barrier additives, gas barrier additives, gas scavengers, and combinations thereof. Such additives may be used in effective amounts, which vary depending upon the property required.

[0041] Examples of suitable opacifying agents, pigments or colorants are iron oxide, carbon black, aluminum, titanium dioxide (T1O2), calcium carbonate (CaCCb), and combinations thereof.

[0042] Cavitating or void- initiating additives may include any suitable organic or inorganic material that is incompatible with the polymer material(s) of the layer(s) to which it is added, at the temperature of biaxial orientation, in order to create an opaque film. Examples of suitable void-initiating particles are PBT, nylon, solid or hollow pre-formed glass spheres, metal beads or spheres, ceramic spheres, calcium carbonate, talc, chalk, or combinations thereof. The average diameter of the void- initiating particles typically may be from about 0.1 to 10 pm.

[0043] Slip agents may include higher aliphatic acid amides, higher aliphatic acid esters, waxes, silicone oils, and metal soaps. Such slip agents may be used in amounts ranging from 0.1 wt % to 2 wt % based on the total weight of the layer to which it is added. An example of a slip additive that may be useful is erucamide.

[0044] Non-migratory slip agents, used in one or more skin layers of the multilayered films, may include polymethyl methacrylate (PMMA). The non-migratory slip agent may have a mean particle size in the range of from about 0.5 pm to 8 pm, or 1 pm to 5 pm, or 2 pm to 4 pm, depending upon layer thickness and desired slip properties. Alternatively, the size of the particles in the non-migratory slip agent, such as PMMA, may be greater than 20% of the thickness of the skin layer containing the slip agent, or greater than 40% of the thickness of the skin layer, or greater than 50% of the thickness of the skin layer. The size of the particles of such non-migratory slip agent may also be at least 10% greater than the thickness of the skin layer, or at least 20% greater than the thickness of the skin layer, or at least 40% greater than the thickness of the skin layer. Generally spherical, particulate non-migratory slip agents are contemplated, including PMMA resins, such as EPOSTAR™ (commercially available from Nippon Shokubai Co., Ltd. of Japan). Other commercial sources of suitable materials are also known to exist. Non-migratory means that these particulates do not generally change location throughout the layers of the film in the manner of the migratory slip agents. A conventional poly dialkyl siloxane, such as silicone oil or gum additive having a viscosity of 10,000 to 2,000,000 centistokes is also contemplated.

[0045] Suitable anti-oxidants may include phenolic anti-oxidants, such as IRGANOX® 1010 (commercially available from Ciba-Geigy Company of Switzerland). Such an anti oxidant is generally used in amounts ranging from 0.1 wt % to 2 wt %, based on the total weight of the layer(s) to which it is added.

[0046] Anti-static agents may include alkali metal sulfonates, polyether-modified polydiorganosiloxanes, polyalkylphenylsiloxanes, and tertiary amines. Such anti-static agents may be used in amounts ranging from about 0.05 wt % to 3 wt %, based upon the total weight of the layer(s).

[0047] Examples of suitable anti-blocking agents may include silica-based products such as SYLOBLOC^® 44 (commercially available from Grace Davison Products of Colombia, Md.), PMMA particles such as EPOSTAR™ (commercially available from Nippon Shokubai Co., Ltd. of Japan), or polysiloxanes such as TOSPEARL™ (commercially available from GE Bayer Silicones of Wilton, Conn.). Such an anti -blocking agent comprises an effective amount up to about 3000 ppm of the weight of the layer(s) to which it is added.

[0048] Useful fillers may include finely divided inorganic solid materials such as silica, fumed silica, diatomaceous earth, calcium carbonate, calcium silicate, aluminum silicate, kaolin, talc, bentonite, clay and pulp.

[0049] Optionally, nonionic or anionic wax emulsions can be included in the coating(s), , to improve blocking resistance and /or lower the coefficient of friction. Any conventional wax, such as, but not limited to Camauba™ wax (commercially available from Michelman Corporation of Cincinnati, Ohio) that is useful in thermoplastic films is contemplated.

Metallization

[0050] Metallization may be carried out through conventional methods, such as vacuum metallization by deposition of a metal layer such as aluminum, copper, silver, chromium, or mixtures thereof. Following metallization, a coating may be applied to the outer metallized layer“outside” or“inside” the vacuum chamber. In additional embodiment(s), primer(s) may be optionally applied to the core and/or skin layer(s), optionally followed by metal-receptive coating(s) and then metallized, optionally followed by primer(s) and/or printable coating(s) thereon. A non-metal side of the film or label may include adhesive coating(s) on the optionally primed skin or core layers.

[0051] In certain embodiments, the metal for metallization is metal oxide, any other inorganic materials, or organically modified inorganic materials, which are capable of being vacuum deposited, electroplated or sputtered, such as, for example, SiOx, AlOx, SnOx, ZnOx, IrOx, wherein x = 1 or 2, organically modified ceramics“ormocer”, etc. The thickness of the deposited layer(s) is typically in the range from 100 to 5,000 Angstrom or preferably from 300 to 3000 Angstrom.

Surface Treatment

[0052] One or both of the outer surfaces of the multilayered films may be surface-treated to increase the surface energy to render the film receptive to metallization, coatings, printing inks, adhesives, and/or lamination. The surface treatment can be carried out according to one of the methods known in the art including corona discharge, flame, plasma, chemical treatment, or treatment by means of a polarized flame. Priming

[0053] A primer coating may be applied to any layer of the multilayered films. In this case, the film may be first treated by one of the foregoing methods to provide increased active adhesive sites thereon and to the thus -treated film surface there may be subsequently applied a continuous coating of a primer material. Such primer materials are well known in the art and include, for example, epoxy, poly(ethylene imine) (PEI), and polyurethane materials. U.S. Pat. No. 3,753,769, U.S. Pat. No. 4,058,645 and U.S. Pat. No. 4,439,493, each incorporated herein by reference, discloses the use and application of such primers. The primer provides an overall adhesively active surface for thorough and secure bonding with the subsequently applied coating composition and can be applied to the film by conventional solution coating means, for example, by roller application.

Coating

[0054] In some embodiments, one or more coatings, such as for barrier, printing, adhesivity, and/or metal-receptivity, may be applied to outer surface(s) of the multilayered films. Such coatings may include, but are not limited to, acrylic polymers, ethylene acrylic acid (EAA), ethylene methyl acrylate copolymers (EMA), polyurethane-based polymers, cationic polymers, epoxy-based polymers, polyvinyl-alcohol-based polymers, polyvinylchloride-based polymers or combinations thereof. The coatings may be applied by an emulsion coating technique or by co-extrusion and/or lamination· One or more coatings of the same or different coatings may be applied on top of each other to either or both of the film’ s print and adhesive sides. Furthermore, the coatings may include crosslinker(s), such as amine- based, metal-oxide based, silane-based, melamine formaldehyde, carbodiimide, hydroxyl- based, acidic crosslinkers or isocyanate-based polymers.

[0055] Before applying the coating composition to the appropriate substrate, the outer surface(s) of the film may be treated as noted herein to increase its surface energy. This treatment can be accomplished by employing known techniques, such as flame treatment, plasma, corona discharge, film chlorination, e.g., exposure of the film surface to gaseous chlorine, treatment with oxidizing agents such as chromic acid, hot air or steam treatment, flame treatment and the like. Although any of these techniques is effectively employed to pre treat the film surface, a frequently preferred method is corona discharge, an electronic treatment method that includes exposing the film surface to a high voltage corona discharge while passing the film between a pair of spaced electrodes. After treatment of the film surface, the coating composition is then applied thereto and optionally metallized. Orienting

[0056] The films herein are also characterized in certain embodiments as being biaxially oriented. The films can be made by any suitable technique known in the art, such as a tentered or blown process, LISIM™, and others. Further, the working conditions, temperature settings, lines speeds, etc. will vary depending on the type and the size of the equipment used. Nonetheless, described generally here is one method of making the films described throughout this specification. In a particular embodiment, the films are formed and oriented, biaxially or monoaxially, using the tentered method. In the tentered process, line speeds of greater than 100 m/min to 400 m/min or more, and outputs of greater than 2000 kg/h to 4000 kg/h or more are achievable. In the tenter process, sheets/films of the various materials are melt blended and coextruded, such as through a 3, 4, 5, 7-layer die head, into the desired film structure. Extruders ranging in diameters from 100 mm to 300 or 400 mm, and length to diameter ratios ranging from 10/1 to 50/1 can be used to melt blend the molten layer materials, the melt streams then metered to the die having a die gap(s) within the range of from 0.5 or 1 to an upper limit of 3 or 4 or 5 or 6 mm. The extruded film is then cooled using air, water, or both. Typically, a single, large diameter roll partially submerged in a water bath, or two large chill rolls set at 20 or 30 to 40 or 50 or 60 or 70°C are suitable cooling means. As the film is extruded, an air knife and edge pinning are used to provide intimate contact between the melt and chill roll.

[0057] Downstream of the first cooling step in this embodiment of the tentered process, the unoriented film is reheated to a temperature of from 80 to 100 or 120 or l50°C, in one embodiment by any suitable means such as heated S-wrap rolls, and then passed between closely spaced differential speed rolls to achieve machine direction orientation. It is understood by those skilled in the art that this temperature range can vary depending upon the equipment, and in particular, upon the identity and composition of the components making up the film. Ideally, the temperature will be below that which will melt the film, but high enough to facilitate the machine direction orientation process. Such temperatures referred to herein refer to the film temperature itself. The film temperature can be measured by using, for example, infrared spectroscopy, the source aimed at the film as it is being processed; those skilled in the art will understand that for transparent films, measuring the actual film temperature will not be as precise. The heating means for the film line may be set at any appropriate level of heating, depending upon the instrument, to achieve the stated film temperatures.

[0058] The lengthened and thinned film is passed to the tenter section of the line for TD orientation. At this point, the edges of the sheet are grasped by mechanical clips on continuous chains and pulled into a long, precisely controlled hot air oven for a pre-heating step. The film temperatures range from 100 or 110 to 150 or 170 or l80°C in the pre-heating step. Again, the temperature will be below that which will melt the film, but high enough to facilitate the step of transverse direction orientation. Next, the edges of the sheet are grasped by mechanical clips on continuous chains and pulled into a long, precisely controlled hot air oven for transverse stretching. As the tenter chains diverge a desired amount to stretch the film in the transverse direction, the process temperature is lowered by at least 2°C but typically no more than 20°C relative to the pre-heat temperature to maintain the film temperature so that it will not melt the film. After stretching to achieve transverse orientation in the film, the film is annealed at a temperature below the melting point, and the film is then cooled from 5 to 10 or 15 or 20 or 30 or 40°C below the stretching temperature, and the clips are released prior to edge trim, optional coronal, printing and/or other treatment can then take place, followed by winding.

[0059] Thus, TD orientation is achieved by the steps of pre-heating the film having been machine oriented, followed by stretching and annealing it at a temperature below the melt point of the film, and then followed by a cooling step at yet a lower temperature. In one embodiment, the films described herein are formed by imparting a transverse orientation by a process of first pre-heating the film, followed by a decrease in the temperature of the process within the range of from 2 or 3 to 5 to 10 or 15 or 20°C relative to the pre-heating temperature while performing transverse orientation of the film, followed by a lowering of the temperature within the range of from 5 to 10 or 15 or 20 or 30 or 40°C relative to the melt point temperature, holding or slightly decreasing (more than 5%) the amount of stretch, to allow the film to anneal. The latter step imparts the low TD shrink characteristics of the films described herein. Thus, for example, where the pre-heat temperature is l20°C, the stretch temperature may be H4°C, and the cooling step may be 98°C, or any temperature within the ranges disclosed. The steps are carried out for a sufficient time to affect the desired film properties as those skilled in the art will understand.

[0060] Thus, in certain embodiments the film(s) described herein may be monoaxially or biaxially oriented with at least a 5 or 6 or 7 or 8 -fold TD orientation and/or at least a 2 or 3 or 4-fold MD orientation

INDUSTRIAL APPLICABILITY

[0061] The disclosed multilayered films and labels may be stand-alone films, laminates, or webs. The disclosed multilayered films may be prepared by any suitable methods comprising the steps of co-extruding a multilayered film according to the description and claims of this specification, orienting and preparing the film for intended use such as by coating, printing, slitting, or other converting methods.

[0062] For some applications, it may be desirable to laminate the multilayered films to other polymeric film or paper products for purposes such as labelling and packaging. These activities are typically performed by the ultimate end-users or film converters who process films for supply to the ultimate end-users.

[0063] The prepared multilayered film may be used as a flexible packaging film to package an article or good, such as a food item or other product. In some applications, the film may be formed into a pouch type of package, such as may be useful for packaging a beverage, liquid, granular, or dry-powder product.

EXAMPLE EMBODIMENTS

[0064] The following four BOPP film structures were produced for metallization. The quality and appearance of base film is important in determining the final conformable performance and appearance of the film.

Structure 1 - a coextruded base film

The compositions of the conformable core and/or skin(s) may comprise, consist essentially of, or consists of the above-listed materials in the second column of Structures 1 and 2. MDPE stands for medium-density polyethylene, PB stands for propyl-butylene, and EPB stands for ethyl-propyl-butylene. As for the core having > 50% iPP + < 50% propylene-a-copolymer(s), their specific combination could be any combination that sums 100% or less.

Structure 2 - a coextruded base film

Structure 3 - a coated, coextruded base film Structure 3 is the coextruded base film of Structure 1 that further includes a coating(s), applied inline or out of line, onto the MDPE-skin. In one example embodiment, the coating(s), optionally primed and/or treated, is applied to the water-bath side of the coextruded base film - e.g., the MDPE-skin side - wherein the water-bath side cools down the coextruded base film and improves the surface smoothness for application of the receptive coating. Otherwise, the coating(s) may be applied to the non-water-bath side. In some instances, the receptive coating may be a metal-receptive coating, which may contain functional groups, such as hydroxyl groups, so as to provide improved laydown in terms of one or more of metal adhesion, appearance, density, uniformity and planarity.

Structure 4 - a coated, coextruded base film

Similar to the description regarding Structure 3, Structure 4 is the coextruded base film of Structure 2 instead of Structure 1, and further includes a coating(s), applied inline or out of line, onto the skin layer of PB(s), EPB(s), or combinations thereof, which may be on the water- bath side or not.

[0065] Metallization of coextruded base films or coated, coextruded base films ensued. The foregoing base films were treated and metallized on the water-bath side with an optical density of 1.8 to 2.8. Pictorially, these metallized films are:

Structure 5 - a metallized, coextruded base film ( ._<?., metallized Structure 1)

Structure 6 - a metallized, coextruded base film ( ._<?., metallized Structure 2) Notably, PB and EPB skins perform better than solely PP because PB and EPB provide better adhesion than just PP alone while still providing remarkable smooth surfaces that PP provides.

Structure 7 - a printable, metallized, coated, coextruded base film

(/._<?., printable, metallized Structure 3)

Structure 8 - a printable, metallized, coextruded base film

(/._<?., metallized Structure 1) with adhesive

Structure 9 - a printable, metallized, coextruded base film

(/._<?., metallized Structure 2) with adhesive

[0066] Structure 10 is an example embodiment of a standard metallized, BOPP base film having a polypropylene core, no propylene-a-copolymer, and no conformability. The BOPP base film is 50 pm in thickness and the core layer is composed of Total PPH4050, a homo- polypropylene from Total Petrochemicals. The tie layer as indicated is composed of PPH4050, a homo-polypropylene from Total Petrochemicals. The skin layers on each side of the core is composed of Adsyl^® 5C39F, an ethylene -propylene-butene terpolymer available from LyondellBasell.

Structure 10

[0067] As an example of experiments on the foregoing structures, below is Table 1, which shows various print-side primers, printable coatings, adhesive side primers and adhesive coatings applied to metallized film structure 5 that was produced on a manufacturing line unless noted otherwise.

Table 1

n.b .: the“print-side” is the metal side of the film, and the“adhesive-side” is on the side opposite of the metal side of the film. All coated structures were produced from metallized basefilm produced from manufacturing line unless otherwise noted.

[0068] Below are explanations of the compositions of the primers and coatings shown in Table 1.

Primer 1

Primer 2

Primer 3

Generally, permissible primers comprise, consists essentially of, or consists of acrylic-, polyethylene-imine- or polyurethane-based polymers. Primer characteristics are to provide good adhesion to the metal surface, i.e., before application of the print-receptive coating (aka “printable coatings”) and/or adhesive coatings.

Coating 1

Coating 2

Coating 3

Coating 4

Coating 5 n.b .: (1) acrylic polymer Neocryl FL780XP was obtained from DSM Neoresins; (2) Dyflex Acrylic copolymer is obtained from Dyflex; (3) ethylene acrylic acid copolymer AQ-2077 was obtained from Paramelt; (4) cationic copolymer is obtained from Owensboro Polymers as Rhiza Rl 11XL coating; and (5) adhesion promoter is AAEM = acetoacetoxyethyl methacrylate monomer obtained from Aldrich chemicals. “Phr” stands for parts per hundred in solids.

[0069] In addition to the foregoing, the adhesive and/or printable coatings may include crosslinker(s). In the case of adhesive coatings, the crosslinker(s) may be amine- or isocyanate- based polymers. In the case of printable coatings, the crosslinker(s) may be acrylic-, polyurethane-, cationic, or epoxy-based polymers.

[0070] Turning now to Figure 1, UV-ink adhesion tests were performed on samples 1-8 shown in Table 1. The tape test for the UV-ink adhesion was performed using 3M Scotch tape8l0-l was used. Approximately six inches in length was applied on the coated film and let to adhere for 1 minute. The tape was then pulled off. [0071] UV-ink print and adhesion tests based on FIN AT FTM21 Ink adhesion basic - EN - 9th edition were carried out to investigate the fitness for use performance of these films in label applications. UV-ink drawdowns were performed using an IGT printer with 4 different gravures to replicate different levels of ink transfer. The UV-ink print performance of coated samples 1-7 in Table 1 improved drastically in comparison to control, which was an uncoated metallized film, /._<?., sample 8 in Table 1. Print-receptive coatings 1, 2, and 4-7 showed excellent ink adhesion performance, /._<?., 100% UV-ink adhesion, at various ink loadings. The various ink loadings tested were 7 ml/m² lane, 9 ml/m² lane, 11 ml/m² lane, and 16 ml/m² lane, respectively, for each sample, /._<?., each of the four columns from left to right as shown by increasingly darkening shades of gray. Print-receptive coating 3 had lower UV-ink adhesion when printed with 16 ml/m² lane gravure, /._<?., partial UV-ink adhesion failure. Comparatively, sample 8 has complete UV-ink adhesion failure.

[0072] Turning now to Figure 2, adhesive adhesion test results based on FIN AT FTM1 low speed peeling 180 degree - 9th edition 2014 UK are shown for Samples 4-7 from Table 1. Three different adhesives were tested on these sample films’ non-metal side: (1) a permanent adhesive, Acranol A225; (2) a removal adhesive, Acranol A2445; and (3) a solvent-based adhesive, Duratack-l84, wherein (1) and (2) were water-based. Each sample has three bars in Figure 2, wherein the peeling strength is shown for (l)-(3) from left to right. The adhesives were coated on the adhesive side of the film, aged for 24h, and then applied to glass substrates. Their peeling strength was measured with a tensile tester capable of peeling a laminate through an angle of 180° with a jaw separation rate of 300 mm per minute with an accuracy of ± 2%. Also, visual observation was performed to confirm complete adhesive transfer after peeling. That was no adhesive observed on the glass panel after peeling off the label. The data in Figure 2 shows that Samples 4-7 performed at acceptable levels.

[0073] Figure 3 pictorially depicts the blocking performance based on ITM90 based on ASTM D3354-08 blocking load plastic film parallel plate method 201004 of samples 1-8 from Table 1. The blocking tests were performed to determine whether samples 1-8 were non- blocking, an important parameter for pres sure- sensitive labels and films. The one-side coated samples 1-3 showed very low blocking performance. The two-sided coated samples showed a slightly higher blocking performance. Nonetheless, all of samples 1-7 showed industry- acceptable non-blocking performance.

[0074] Conformable labels may go through several squeezing cycles during their usage. The repeated squeezing of the conformable-labelled container may lead to damage of the label, resulting in wrinkles and metal surface scratches as well as degrading the appearance of the film. Hence, optimal flexibility and robustness of the film is important for the metallic appearance of the film. The robustness of the metallic layer may be modified by the type of film, skin layer to be metallized or by overcoating the metal surface without affecting the conformability of the film.

[0075] To understand this behavior, a further surface scratchability test was carried out with a washability tester from Braive instruments. The test is based on ASTM D2486 - D4213- DIN 53778 - ISO 11998. A sample, approximately 430 mm long and 85 mm wide, was cut and placed on the washability tester table. The samples were then scrubbed with brush N° 1720P009 - Brush ASTM D2486 (Nylon) and brush N° 1720P004 - Brush DIN 53 778 (boar fur) for 10 repeated cycles. The length of scrub is typically between 170 and 290 mm. For the current study maximum length of 290 mm was used. After the scratch test, the samples were visually ranked based on the degradation of the metal surface.

[0076] To establish the metal resistance scale, surface scratch resistance with a washability tester was performed on the control samples. Since metallized film structure 10 is based only on polypropylene resins, it was used as base metallized film to establish a metal resistance scale. Different metal-side-coated samples based on structure 10 were produced as shown in Table 2. The samples were then visually observed and scaled as shown in Figure 4. Metal resistance scale was established as level 0 = no scratches and level 4 = more than 50% metal degradation evaluation.

Table 2

[0077] The following study was then carried out to investigate the surface scratchability of the conformable film. Table 3 describes the samples produced during the study. Selected samples were then investigated for surface scratch resistance.

* Only number indicates structure produced on manufacturing line

PL = Basefilmfor metallization Produced on pilot line;

NA = Not applicable

Table 3 [0078] Scratch resistance with a washability tester was then performed on samples 9-24 in

Table 3. The visual image of the samples after the black nylon brush scratch test is shown in Figure 5. As can be seen, Figure 5 identifies the following column headers: the sample number as explained by Table 3, replicate number (/._<?., the scratch test was run twice on each sample), where performed (/._<?., brush scratches performed on metal side of film), method of the test (/._<?., used the washability tester at a speed of l5m/min), the fact that no weights were added to make the brush’s action more forceful, that the scratch tests were on the dry surface, that each scratch test had 10 cycles of scratching, wherein each scratching was a back and forth trip on the surface, a picture of the scratched metal surface, and a metal-resistance score. The visual image of the samples after the boar fur brush scratch test is shown in Figure 6, which has the same column headers as Figure 5. The samples were then ranked as established by metal resistance scale. The summary of the ranking is depicted in Figure 7. In general, except for sample 24 the samples based on metallized film structure 10 performs the best for surface scratchability, /._<?., they have the least metal surface scratching. Structure 10 has no propylene- a-copolymer in the core and no conformability. The film type based on PL6 performs the second best, wherein its metallized skin comprises an ethylene -propylene-butylene terpolymer with propylene- a-copolymer in the core to provide conformability to the structure. In general, films based on structure 5 and PL5 have the lowest resistance to surface scratchability. This structure has propylene- a-copolymer in the core providing the conformability and a MDPE skin adjacent to the metallized layer.

[0079] Further, top-coating of the metallized surface enhances resistance to surface scratchability of the film. For instance, metallized base film structure 10 with no surface top coating shows complete degradation of the metal surface as shown in Figure 4. Interestingly, the type of primer used affects the surface scratchability, especially for films based on conformable structure. For instance, sample pairs 9 and 13, 10 and 14, and 11 and 15 have identical conformable cores and skin layer adjacent to the metal and top coating. However, samples 9, 10 and 11 have acrylic copolymer and ethylene-acrylic-acid-based primer between the metal layer and top coating and show better surface-scratch-resistance performance in comparison to samples 13, 14, and 15 with polyurethane primer. Additionally, comparing samples 10 and 11 that were produced on same pilot line, sample 11 with copolymer skin adjacent to the metal has better scratch resistance with a black nylon brush. A similar trend is observed for boar fur brush scratchability for samples 22 and 23. Finally samples 21, 22 and 23 based on top coating 3 have in general superior performance, this is potentially due to the high wax content of this coating in combination with the polymer matrix.

[0080] In addition to the above-described base film, the visual appearance or brilliance of the metallized film may be affected by metal- wire purity used for metallization process as well as laydown and smoothness of the metalized surface. Metal brilliance is based on relative comparison to previous film samples stored in a reference book in the quality control laboratory. While this is an effective way to ensure that fit for use product is being generated, another more quantitative approach employed in this invention is distinctness of image (“DOI”). DOI is a quantification of the distinctness or clarity of images reflected by the metallized film. The DOIs of the metallized films were measured using Elcometer 408 Gloss & DOI Meter that provided DOI values using the ElcoMaster Data Management software V2.0.53 provided with the instrument. The DOI measurements are carried out and reported on the transverse direction (TD) of the film. The scale values obtained with the measuring procedures of these methods range from 0 to 100 with a value of 100 representing perfect DOI (image clarity).

[0081] Notably, DOI measured on the metallized side of the film is influenced by the type of the skin layer underneath. Figure 8’s DOI data is for two different metallized base films, based on structures 5 and 6, prior to coating these films with print-receptive coating. The DOI of metallized film based on structure 6 is superior to metallized film based on structure 5.

[0082] Additionally Figure 9 depicts the percentage reflectance measured using Elcometer 408 Gloss and DOI Meter on the metallized side of structures 5 and 6. The shinier a surface is, the closer the percentage reflectance value is to 100%, i.e., complete reflectance. Structure 6 has higher percentage reflectance compared to structure 5.

[0083] Below are example embodiments of the disclosed invention written in claim format:

1. A conformable, metallized film comprising:

a core layer consisting essentially of > 50 wt.% isotactic polypropylene, < 50 wt.% propylene-a-copolymer(s), and optionally additives; a first skin layer and a second skin layer on opposing sides of the core layer, wherein the first skin layer and second skin layer consist essentially of: (i) medium-density polyethylene polymers or (ii) propyl-butylene polymers, ethyl-propyl-butylene polymers, or combinations thereof, and (iii) optionally additives; a metallized layer on one side of the first skin layer, wherein the one side of each of the first skin layer and the second skin layer faces away from the core layer, wherein the metallized layer has an optical density > 1.8; and a primer layer comprising about 50 wt % or more of acrylic-based, polyethylene-imine-based or polyurethane-based polymers.

2. The conformable, metallized film of claim 1, further comprising tie layer(s) between the core layer and: (i) the first skin layer; (ii) the second skin layer; or (iii) both (i) and (ii).

3. The conformable, metallized film of claim 1, wherein percentage reflectance is at least 35% on the metallized layer in a transverse direction when the metallized layer is coated.

4. The conformable, metallized film of claim 1, further comprising at least one metal- receptive coating between the first skin layer and the metallized layer.

5. The conformable, metallized film of claim 1, where the at least one metal-receptive coating is inline-applied.

6. The conformable, metallized film of claim 1, wherein the at least one metal-receptive coating comprises functional groups.

7. The conformable, metallized film of claim 1 , further comprising at least one print-receptive coating on a side of the metallized layer, wherein the side faces away from the core layer.

8. The conformable, metallized film of claim 7, wherein UV-ink adhesion on the at least one print-receptive coating is about 100% with UV-ink loading within a range from 7 ml/m² lane through 11 ml/m² lane.

9. The conformable, metallized film of claim 7, wherein the print-receptive coating comprises acrylic -based, polyethylene-imine-based or polyurethane-based polymers. 10. The conformable, metallized film of claim 7, wherein the print-receptive coating has a wax additive.

11. The conformable, metallized film of claim 7, wherein the print-receptive coating further comprises one or more cationic components.

12. The conformable, metallized film of claim 1, further comprising an adhesive-receptive coating on the one side of the second skin layer, wherein the adhesive coating has a wax additive.

13. The conformable, metallized film of claim 1, further comprising an adhesive-receptive coating on the one side of the second skin layer, wherein the adhesive coating has a crosslinking agent.

14. The conformable, metallized film of claim 1, further comprising an adhesive-receptive coating on the one side of the second skin layer, wherein the conformable, metallized film has a peeling strength below 40 g/mm² at about 23 °C.

15. The conformable, metallized film of claim 1, further comprising at least one adhesive- receptive coating on the one side of the second skin layer, and optionally a release liner on the at least one adhesive -receptive coating.

16. The conformable, metallized film of claim 1, wherein a surface of the metallized layer is scratched 10% or less below the surface when scrubbed 10 cycles on a washability tester table with a nylon brush number 1720P009.

17. The conformable, metallized film of claim 1, wherein the core layer, the first skin layer, the second skin layer, and any tie layers are oriented in at least one direction.

18. The conformable, metallized film of claim 1, wherein the metallized layer is a deposited layer of metal or metal oxide.

19. The conformable, metallized film of claim 1, wherein the primer further comprises a crosslinker.

20. The conformable, metallized film of claim 1, wherein the primer layer further comprises additives.

21. The conformable, metallized film of claim 1, wherein the primer consists essentially of or consists of ethylene acrylic acid copolymer so as to exclude other acrylic-based, polyethylene-imine-based or polyurethane-based polymers.

22. The conformable, metallized film of claim 1, wherein distinctness of image on the metallized layer is at least 25% in a transverse direction when the metallized layer is coated.

23. The conformable, metallized film of claim 1, wherein distinctness of image on the metallized layer is at least 90% in a transverse direction when the metallized layer is coated.

Claims

CLAIMS What is claimed is:

1. A conformable, metallized film comprising:

a core layer consisting essentially of > 50 wt.% isotactic polypropylene, < 50 wt.% propylene-a-copolymer(s), and optionally additives;

a first skin layer and a second skin layer on opposing sides of the core layer, wherein the first skin layer and second skin layer consist essentially of: (i) medium-density polyethylene polymers or (ii) propyl-butylene polymers, ethyl-propyl-butylene polymers, or combinations thereof, and (iii) optionally additives;

a metallized layer on one side of the first skin layer, wherein the one side of each of the first skin layer and the second skin layer faces away from the core layer, wherein the metallized layer has an optical density > 1.8; and

a primer layer on the metallized layer, wherein the primer layer comprises about 50 wt % or more of acrylic-based, polyethylene-imine-based or polyurethane-based polymers.

9. The conformable, metallized film of claim 7, wherein the print-receptive coating comprises acrylic -based, polyethylene-imine-based or polyurethane-based polymers.

10. The conformable, metallized film of claim 7, wherein the print-receptive coating has a wax additive.

14. The conformable, metallized film of claim 1, further comprising an adhesive-receptive coating on the one side of the second skin layer, wherein the conformable, metallized film has a peeling strength below 40 g/mm² at 23 °C.

21. The conformable, metallized film of claim 1, wherein the primer consists essentially of ethylene acrylic acid copolymer.