Water-resistant and repulpable composition

Abstract

Disclosed herein is a printable paper comprising a cellulosic substrate having a first surface and a second surface opposite the first surface, the printable paper having a thickness of 20 g / m 2 The printable paper has a 2 minute Cobb sizing value of less than 100 mm and the first surface, the second surface, or both have a surface energy of more than 37 dynes / cm. Further disclosed herein are protective transport bags, such as those obtained from the printable paper, and reusable flexible packaging containers, such as those including the printable paper. Also disclosed herein are methods of making the reusable flexible packaging containers.

Description

[Technical Field]

[0001] Cross-reference of related applications This application claims the interests of U.S. Patent Application No. 63 / 159,287, filed on March 10, 2021, the disclosure of which is expressly incorporated herein by reference in its entirety.

[0002] This disclosure relates to packaging compositions, and more specifically to water-resistant and repulpable transport packaging and paper, as well as methods for producing and using them. [Background technology]

[0003] Packaging materials for the retail and transport of products are typically durable enough to allow for the use of reliable materials. Typical considerations in the development of such materials include their barrier properties, tensile and tear strength, resistance to wrinkles and abrasion, manufacturing efficiency, and handling resistance, resistance to rodent and pest infestation, as well as the ability of materials and packaging made from them to deter theft. Packaging and packaging materials are also preferably relatively inexpensive to manufacture and preferably have an appearance, print quality, feel, and tactile appeal to customers so as to not only promote the use of the product but also enhance the image or relevance of the product.

[0004] While plastic and Tyvek substrates offer superior advantages over fibrous materials in terms of durability and water repellency, these materials are over-engineered for many e-commerce transport applications. More importantly, they are becoming increasingly unpopular with many brands from an environmental perspective. Several groups advocate for the use of paper and cardboard, or other products made from wood pulp. In the manufacture of paper and cardboard, or other products made from wood pulp, petroleum-derived paraffin waxes and synthetic polymers have long been used as moisture-proofing agents, water-repellent agents, oil-repellent agents, reinforcing agents, strengthening agents, and release agents. Aside from paraffin, the most frequently used material is polyethylene, but other widely used polymers include polymerized acrylics, vinyls, styrenes, ethylenes, and copolymers or heteropolymers of these monomers. Because petroleum-derived polymers, and petroleum waxes in particular, are not biodegradable in papermaking whitewater (recirculated treated water) and wastewater, paper and cardboard to which these conventional materials are applied becomes difficult, and often impossible, to repulp and reuse in standard papermaking processes. In addition, petroleum wax residues not removed from pulp fibers during the repulping and recycling process cause serious problems due to accumulation on screens and felts used during the formation and manufacturing process of paper or cardboard sheets. Furthermore, paper and cardboard coated or impregnated with petroleum wax resist biodegradation and composting when disposed of in landfills and other waste disposal systems. Paper and cardboard coated or impregnated with conventional synthetic polymers and heteropolymers are also difficult, and often impossible, to repulp and reuse due to their resistance to separation from fibers in standard repulping processes, resulting in significant fiber loss in attempts to repulp and reuse them, and these are also not biodegradable and therefore resistant to composting.

[0005] Furthermore, conventional paper and cardboard used in commercial transport applications are typically bulky, increasing the cost of packaging.

[0006] Therefore, there is a need to provide reusable and durable shipping packaging for use in, for example, apparel and non-fragile goods, as an alternative to plastic and non-recyclable shipping packaging. The compositions and methods disclosed herein address these and other needs. [Overview of the project]

[0007] This disclosure relates, in general, to printable paper for use as packaging containers, more specifically, commercial protective bags. Commercial protective bags are used, for example, for transporting apparel and non-fragile goods. This disclosure provides an environmentally sustainable alternative to protective bags made from plastics and other non-recyclable materials, while offering an attractive aesthetic as well as certain levels of durability, water resistance, weight, and overall performance important for commercial applications.

[0008] The printable paper comprises a cellulose-based substrate having a first surface and a second surface facing the first surface, and the printable paper has a density of 20 g / m². 2 It has a Cob sizing value of less than 2 minutes, and the first surface, the second surface, or both have a surface energy greater than 37 dynes / cm. In some embodiments, the printable paper is repulpable according to the Fiberboard Association Voluntary Standard for Repulping and Recycling Corrugated Fiberboard Treated to Improve its Performance in the Presence of Water and Water Vapor August 16, 2013:Appendix A:Repulpability. In certain embodiments, the printable paper is at least 45 lb as determined by TAPPI T494. f / in or at least 70lb f Tensile strength (MD) in / in is indicated. Printable paper is 120 lbs / 3000 ft. 2 The following, or 60 lbs / 3000 ft 2 ~120lbs / 3000ft 2may have a basis weight. In some embodiments, the printable paper is 15 g / m 2 and has cob sizing for less than 2 minutes. In certain embodiments, the first surface, the second surface, or both have a surface energy of 40 dynes / cm to 45 dynes / cm. The printable paper may exhibit a tensile energy absorption (MD) of at least 200 J / m 2 as determined by TAPPI T494. In some embodiments, the printable paper exhibits a tear resistance (MD) of at least 170 gf as determined by TAPPI T414. In a specific embodiment, the tensile index (MD) defined by dividing the tensile strength (N / m) by the basis weight (g / m 2 ) is 70 to 95 Nm / g. The printable paper may be manufactured with strength characteristics highly suitable for commercial protective bag applications with a basis weight of 120 lbs / 3000 ft 2 or less (e.g., 60 lbs / 3000 ft 2 to 120 lbs / 3000 ft 2 , 69 lbs / 3000 ft 2 to 120 lbs / 3000 ft 2 , or 60 lbs / 3000 ft 2 to 100 lbs / 3000 ft 2 ).

[0009] In a specific embodiment, the cellulosic substrate (also referred to herein as the base sheet or base stock) can be manufactured from a fiber furnish comprising at least 50 wt% post-consumer waste (PCW, e.g., PCW having up to 30 wt% bleached softwood and up to 70 wt% bleached hardwood) and at least 40 wt% softwood pulp. The softwood pulp preferably contains at least 75% kraft fibers. For example, the cellulosic substrate may include 50% PCW and 50% northern bleached softwood kraft (NBSK) composed mainly (>75%) of kraft fibers. The use of bleached fibers provides an opportunity to manufacture custom colors for brand differentiation. Overall, the cellulosic substrate can be obtained from at least 60 wt% softwood and 40 wt% or less hardwood.

[0010] In certain embodiments, the cellulosic substrate includes a dry strength additive. In certain embodiments, the dry strength additive includes cationic starch and polyacrylamide resin. Cationic starch and polyacrylamide resin may be added to the wet side of the papermaking machine. Suitable cationic starches include quaternary ammonium cationic starch, tertiary amino cationic starch, or a combination thereof. Cationic starch may be present in an amount of at least 1% by weight, or 1% to 2.5% by weight, of the cellulosic substrate. Suitable polyacrylamide resins may include anionic or cationic polyacrylamide resins, such as glyoxalized polyacrylamide resin (Hercobond 1000 available from Solenis), or anionic polyacrylamide-acrylic acid (Hercobond 2000 available from Solenis). Polyacrylamide resin may be present in an amount of at least 0.1% by weight, 0.1% to 0.5% by weight, or 0.2% to 0.4% by weight, of the cellulosic substrate.

[0011] In some embodiments, the printable paper further comprises a barrier coating on a first surface of a cellulose-based substrate. The barrier coating is 2 g / m² 2 ~20g / m 2 , 2g / m 2 ~15g / m 2 , or 5g / m 2 ~12g / m 2The coating may have a weight of . In certain embodiments, the printable barrier coating is obtained from an aqueous polymer. In certain embodiments, the aqueous polymer coating includes acrylic homopolymers, acrylic copolymers, polyester acrylic copolymers, vinyl acrylic copolymers, wax emulsions, or combinations thereof. The printable barrier coating may be surface-treated with high-energy discharge, and in some embodiments, the printable barrier coating may be surface-treated using corona treatment. Corona treatment can increase the surface energy (dyne level) to a range acceptable for most printing and bonding processes while still maintaining protection from wet environments. Corona treatment can also create crosslinks on the barrier surface that reduce interdiffusion of polymer chains, thereby altering the failure mode of the material. In some embodiments, the printable barrier coating further includes inorganic particles such as silica. In certain embodiments, the inorganic particles are surface-treated. Barrier coatings are provided to protect from humid environments, but generally impart a low surface energy to the coated substrate, thus delaying water penetration and impairing printability (including ink absorption and drying), as well as the adhesion of low-temperature liquid adhesives, hot melts, and pressure-sensitive adhesives used to manufacture protective bags.

[0012] In some embodiments, the printable paper further includes a backing coating on a second surface of the cellulosic surface. In certain embodiments, the backing coating includes a film-forming hydrophilic polymer. Examples of suitable film-forming hydrophilic polymers include polyvinyl alcohol, polyester elastomers, natural polymers (e.g., starch, gum, or cellulose), or combinations thereof. The backing coating has a density of 0.1 g / m². 2 ~5g / m 2 , or 0.2g / m 2 ~2g / m 2 It can be applied with a coating weight of 1 to 75 micrometers or with a thickness of 1 to 25 micrometers.

[0013] Also provided herein are transport protective bags obtained from the printable paper described herein. In some embodiments, the entire transport protective bag is obtained from the printable paper. In certain embodiments, the transport protective bag is an envelope.

[0014] Also provided herein are reusable and flexible packaging containers comprising printable paper containing a cellulosic substrate, wherein a first surface forms the outer surface of the container, and a second surface forms the inner surface of the container and defines the product volume. In some embodiments, all materials forming the container are reusable in a single stream. In certain embodiments, the container is an envelope. Also provided herein is a method for producing a reusable and flexible packaging container comprising the printable paper described herein, comprising forming an outer surface of the container including a first surface and forming an inner surface of the container including a second surface, wherein the second surface defines the product volume.

[0015] Reusable packaging containers offer a choice of lightweight, moisture-resistant, and repulpable fiber-based protective bags. More specifically, this disclosure offers advantages over existing fiber-based packaging containers in terms of weight, water resistance, durability, reusability, aesthetics, and the incorporation of consumer waste fibers in its structure. Cellulosic substrates provide strength and durability. Tensile strength, tensile energy absorption, tear strength, and burst strength are maximized through the selection of fiber types, refining methods, and the use of cationic starch and polyacrylamide dry strength resins. Internal sizing of the base stock can ensure repulpability by allowing water penetration on the reverse side while providing durability of the surface barrier coating. For example, to provide protection from rain, snow, and humid environments, the barrier coating is applied to one side of the base stock.

[0016] Details of one or more embodiments are described below. Other features, purposes, and advantages will become apparent from the description and claims. [Modes for carrying out the invention]

[0017] This disclosure relates, in particular, to printable paper for transport packaging. The printable paper comprises a cellulosic substrate having a first surface and a second surface opposite the first surface. In some embodiments, the printable paper further comprises a barrier coating on the first surface of the cellulosic substrate. This disclosure also relates to transport protective bags, such as those obtained from the printable paper, and reusable and flexible packaging containers, such as those containing the printable paper. Methods for producing reusable and flexible packaging containers are also disclosed herein.

[0018] Cellulose-based substrate Cellulosic substrates may include any variety of different materials. In some embodiments, for example, a cellulose-based substrate may contain a fibrous web formed from a cellulose fibrous material. As used herein, the term “cellulose fibrous material” generally refers to a material containing wood pulp or other non-wood-derived fiber sources (e.g., at least about 65% by weight, at least about 75% by weight, at least about 85% by weight, at least about 95% by weight, or up to 100% by weight of the total fibers in the web being cellulose).

[0019] Pulp can be primary fibrous material, secondary fibrous material such as consumer waste ("recycled"), or a combination thereof. Sources of pulp fibers include, for example, wood such as coniferous and hardwood; straw and grass such as rice, African honeysuckle, wheat, rye, and sabay; toad and reeds such as bagasse; bamboo; woody stems such as jute, flax, kenaf, and hemp; basts such as linen and ramie; leaves such as abaca and sisal; and seeds such as cotton and cotton liner. Coniferous and hardwood are more commonly used sources of cellulose fibers. Examples of coniferous woods include, for illustrative purposes only, pine (e.g., longleaf pine, echinata pine, lobe pine, slash pine, southern pine), black spruce, white spruce, Banks pine, balsam fir, Douglas fir, American hemlock, redwood, red cedar, northern coniferous trees, southern coniferous trees, hemlock, spruce (e.g., black spruce), and combinations thereof. Examples of hardwoods, again for illustrative purposes only, include aspen, birch, beech, oak, maple, eucalyptus, and gum. Specific examples of such pulp fibers include coniferous pulp available as Northern Bleached Coniferous Kraft Paper (NBSK) pulp.

[0020] Different cellulose fibers can be selected to provide different attributes. The choice of fiber source depends in part on the final application of the web. For example, softwood fibers can be included in the web to increase tensile strength. Hardwood fibers may be selected for their ability to improve the uniformity of fiber formation or distribution. In certain embodiments, the cellulosic substrate may contain at least about 50 wt% softwood fibers (based on the total dry weight of cellulose fibers in the web), at least about 60 wt% (i.e., about 65 wt% to about 95 wt%, about 75 wt% to about 90 wt%, or about 75 wt% to about 85 wt%), etc. In a particular embodiment, softwood fibers may form substantially 100 wt% of the total cellulose fibers in the cellulosic substrate (i.e., essentially consist of softwood cellulose fibers) without the presence of any significant amount of hardwood fibers. In certain embodiments, the cellulosic substrate may be less than about 50% by weight of hardwood fibers, less than about 45% by weight (i.e., about 15% to about 45% by weight, about 20% to about 40% by weight, or about 25% to about 40% by weight), etc. (based on the total dry weight of cellulose fibers in the web).

[0021] In certain embodiments, cellulosic substrates may be produced from a fiber feed comprising at least 50% by weight of consumer waste (e.g., containing about 15% to about 50% by weight of bleached softwood fibers and about 50% to about 85% by weight of bleached hardwood fibers) and up to 50% by weight of softwood pulp. The softwood pulp preferably contains at least 75% spruce fibers. For example, a cellulosic substrate may comprise 50% northern bleached softwood kraft paper (NBSK) composed of 50% consumer waste and 50% spruce fibers. The use of bleached fibers provides an opportunity to produce custom colors for brand differentiation.

[0022] In some embodiments, the cellulosic substrate is 120 lbs / 3000 ft 2 Below (for example, 115 lbs / 3000 ft) 2 Below, 110lbs / 3000ft 2 Below: 105 lbs / 3000 ft 2 Below, 100 lbs / 3000 ft2 Below: 95 lbs / 3000 ft 2 Below: 90 lbs / 3000 ft 2 Below, 85lbs / 3000ft 2 Below: 80 lbs / 3000 ft 2 Below, 75lbs / 3000ft 2 Below, 70lbs / 3000ft 2 Below: 65 lbs / 3000 ft 2 Below 60lbs / 3000ft 2 Below: 55 lbs / 3000 ft 2 The following, or 50 lbs / 3000 ft 2 The basis weight may be as follows. In some embodiments, the cellulosic substrate is 45 lbs / 3000 ft. 2 (For example, 50 lbs / 3000 ft) 2 Above 55 lbs / 3000 ft 2 Above 60 lbs / 3000 ft 2 Above 65 lbs / 3000 ft 2 Above 70 lbs / 3000 ft 2 Above 75 lbs / 3000 ft 2 Above 80 lbs / 3000 ft 2 Above 85 lbs / 3000 ft 2 Above 90 lbs / 3000 ft 2 Above 95 lbs / 3000 ft 2 Above, 100 lbs / 3000 ft 2 Above 105 lbs / 3000 ft 2 Above 110 lbs / 3000 ft 2 lbs / 3000ft 2 Above 115 lbs / 3000 ft 2 Above, or 120 lbs / 3000 ft 2 The basis weight is (above). In some embodiments, the cellulose substrate is 50 lbs / 3000 ft. 2 ~120lbs / 3000ft 2 (For example, 60 lbs / 3000 ft) 2 ~120lbs / 3000ft 2 70 lbs / 3000 ft 2 ~110 lbs / 3000 ft 270 lbs / 3000 ft 2 ~100lbs / 3000ft 2 , or 75lbs / 3000ft 2 ~100lbs / 3000ft 2 It has a basis weight of ).

[0023] Strengthening additives Strengthening additives may be included in cellulosic substrates to improve dry and temporary wet strength, retention and drainage, productivity, reduce basis weight, improve energy efficiency, lower feed costs, and increase felt life. Strengthening additives can typically provide more or less long-term moisture resistance to thin paper sheet structures. In some cases, high strength is desirable for paper applications, but papers with such characteristics are often only repulpable under harsh conditions. For example, resins containing azetidinium functional groups generally present difficulties in reusing or recovering paper by breaking it down to individual fibers and repulping it. Repulping such paper requires exposing it to sufficient physical force to break down the fiber network while treating it under appropriate thermal and chemical conditions to induce amide hydrolysis. Other strengthening additives may have better repulpability, but their strength may not be as high as that obtained with other strengthening resins.

[0024] The strength additives included in the papers described herein may be cationic, nonionic, anionic, or amphoteric water-soluble resins, which are ideally suited for use as wet and dry strength resins that self-retain on paper and impart improved dry strength and effective wet strength to the paper. Dry strength additives include the strength additives discussed herein that improve the dry strength of the material. Furthermore, papers containing the strength additives described herein pulp faster than papers containing conventional dry and wet strength resins, although they are essentially the same, in some examples. Preferably, the strength additives used in cellulosic substrates described herein may include anionic or cationic polyacrylamide resins, such as those available under the trade name Hercobond®. Specific examples include cationic glyoxylated polyacrylamide and anionic polyacrylamide-acrylic acid resins. Examples of additional strength additives include, but are not limited to, cationic starch, polyamide-polyamine-epichlorohydrin resin, polyaminoamide-epichlorohydrin resin, polyethyleneimine resin and aminoplast resin, modified starch and other polysaccharides (such as amphoteric and anionic starch), guar gum and carob gum, modified polyacrylamide, carboxymethylcellulose, sugars, polyvinyl alcohol, chitosan, modified polyamines, and cellulase enzymes.

[0025] In some embodiments, cellulosic substrates may contain cationic starch. Cationic starch can improve paper strength, water drainage and retention, enhance paper quality, reduce the addition of paper waste, lint, and size, reduce paper web breakage through better control of the papermaking process, and improve the run-through and productivity of papermakers. Cationic starch also reduces supply costs by enabling the use of fillers and more recycled fibers. As a strength additive, cationic starch improves stiffness, opacity, print quality, and brightness. Commercially available cationic starches include quaternary ammonium cationic starch and tertiary amino cationic starch. Quaternary ammonium starch is cationic over the entire pH range, while tertiary amino starch is cationic only in the acidic range.

[0026] Cationic starch strength additives may be included in the cellulose-based substrate in amounts of 0.1% or more by weight, 0.2% or more by weight, 0.4% or more by weight, 0.5% or more by weight, 0.8% or more by weight, 1% or more by weight, 1.5% or more by weight, 2% or more by weight, 2.5% or more by weight, 3% or more by weight, 4% or more by weight, or 5% or more by weight, based on the weight of the cellulose-based substrate.

[0027] In some embodiments, the cellulosic substrate may include anionic or cationic polyacrylamide resins. Cationic and anionic polyacrylamide strength additives are available from Hercules Incorporated of Wilmington, Del. The addition of polymers helps to create composites that add charge to the cellulose fibrous slurry, imparting both durability and strength to the finished cellulose fibrous sheet.

[0028] The polyacrylamide strength additive may be included in the cellulosic substrate in amounts of 0.1% or more by weight, 0.2% or more by weight, 0.4% or more by weight, 0.5% or more by weight, 0.8% or more by weight, 1% or more by weight, 1.5% or more by weight, 2% or more by weight, 2.5% or more by weight, 3% or more by weight, 4% or more by weight, or 5% or more by weight, based on the weight of the cellulose-based substrate.

[0029] In particular, other additives such as processing agents, including but not limited to thickeners, dispersants, emulsifiers, viscosity modifiers, humectants, and pH modifiers, may also be present in the cellulose-based substrate.

[0030] Barrier coating In some embodiments, printable paper may further include a barrier coating on the first surface of a cellulosic substrate. For example, it is current practice to provide moisture barrier by adding films of polyethylene (PE), polypropylene (PP), polyester, wax, or polyvinylidene chloride (PVDC) to the paper substrate. However, conventional barrier coatings are mainly non-repulpable, which leads to quality problems in the fiber recovery process, mainly because they disrupt the process (e.g., clog filter screens) or contaminate the finished product. For environmental and cost reasons, the disposal of moisture barrier packaging materials has become a significant issue for paper mills and their customers. Repulping these materials presents particular challenges to the industry. Moisture barrier layers highlight problems in recovering useful fibers from packaging. Currently, almost all of these packaging materials are ultimately disposed of in landfills or incinerated, which creates environmental and public health problems. Reprocessing packaging materials for the recovery of wood fibers is an important source of wood fibers and helps avoid the disposal of high-quality and valuable fibers.

[0031] Cellulosic substrates may include barrier coatings that can offer high barrier performance, printability, high-performance adhesion, strength, repulpability, and low manufacturing costs. The term "barrier" is used to describe the ability of a coating to stop or delay the passage of atmospheric gases, filling gases, water vapor, volatile fragrances, and / or fragrance components, or combinations thereof.

[0032] Preferably, the barrier coatings described herein are water-resistant. The water resistance of a barrier coating can be tested by the Cobb method described in TAPPI T441, which is incorporated herein in whole by reference. This method determines the amount of water absorbed by paper within a specific time under standardized conditions, and in some embodiments, the coated substrates described herein pass the water resistance test described in this test method. A barrier coating that provides barrier against water and moisture must also have the ability to form a seal and not block during the manufacturing process. For example, paper in a transport protective bag must be able to seal when the sides of the paper are joined, and the seal itself must also be resistant to liquids or water vapor and maintain its integrity in their presence.

[0033] Barrier coatings are preferably printable. Printability is a critical attribute of packaging targeted at retail or point-of-sale (POW) businesses. Printability is the ability of a material to produce high-quality prints. Printability is determined by print quality and uniformity of ink transfer, ink wetting and drying speed, ink receptivity, compressibility, smoothness, opacity, color, picking resistance, and similar factors. It is generally preferable if the material can be printed on a variety of machines, maximizing print quality and minimizing manufacturing costs. Printing technologies include flexographic, gravure, heatset, thermal transfer, offset, offset lithography, non-contact laser, inkjet, ultraviolet, hot stamping, screen, and silkscreen. Overall, printable barrier coatings preferably provide barriers against moisture, oxygen, oil, and fatty acids, as well as improved mechanical performance, aesthetics, decorative properties, chemical resistance, reusability, surface energy, ink adhesion, ink wetting, film adhesion to fibers, and an improved surface for adhesive and bonding applications.

[0034] The printable barrier coatings described herein can be obtained from aqueous polymers and are present on at least one surface of a cellulosic substrate. The aqueous polymer coatings may include aqueous polymers that are water-soluble and / or water-dispersible. In some embodiments, the aqueous polymers may include acrylic homopolymers, acrylic copolymers, polyester acrylic copolymers, vinyl acrylic copolymers, wax emulsions, or combinations thereof. In some embodiments, the aqueous polymer coatings can be obtained from consumer waste such as recycled PET containers. Specific examples of aqueous polymer coatings include commercially available acrylic copolymers from Michelman (e.g., MC40EAF), commercially available acrylic polymers from BASF (e.g., Acronal NX4612X), and commercially available polyester acrylate copolymers from Ulterion International (e.g., Ulterion 560Flex, which is a polyester acrylate copolymer obtained from recycled PET containers).

[0035] The printable barrier coating may contain an aqueous polymer in an amount of at least 60% by weight (e.g., at least 65% by weight, at least 70% by weight, at least 75% by weight, at least 80% by weight, at least 85% by weight, at least 90% by weight, at least 95% by weight, at least 97% by weight, at least 99% by weight, or up to 100% by weight) of the printable barrier coating.

[0036] The barrier coating may further include one or more additives in some embodiments. In some embodiments, one or more additives may include inorganic particles (also referred herein as pigments or mineral pigments). In some embodiments, inorganic particles can be added to impart specific properties to the paper, such as smoothness, whiteness, increased density or weight, decreased porosity, increased opacity, flatness, gloss, water adsorption (low surface tension or contact angle), or water repulsion (high surface tension or contact angle). The inorganic particles may undergo a treatment process to enhance the desired properties. For example, the pigment may be surface-treated with materials including, but not limited to, surfactants, hydrophobic or hydrophilic modified polymers such as polyethyleneimine (PEI), acrylic emulsion chemicals, silanes or siloxanes, or combinations thereof.

[0037] Inorganic particles may include metal oxide microparticles or nanoparticles (such as aluminum oxide (Al2O3), aluminum dioxide (AlO2), zinc oxide (ZnO)), calcium carbonate, kaolin, clay, talc, diatomaceous earth, mica, barium sulfate, magnesium carbonate, vermiculite, graphite, carbon black, alumina, silica, colloidal silica, silica gel, titanium dioxide, aluminum hydroxide, aluminum trihydrate, satin white, magnesium oxide, or combinations thereof. In some embodiments, the inorganic particles include silica (SiO2). While not wishing to be bound by theory, inorganic microparticles are thought to add affinity to the ink of an image printed on a printable barrier coating. For example, porous metal oxide microparticles (e.g., SiO2) are thought to be able to rapidly absorb the ink liquid (e.g., water and / or other solvents) and retain ink molecules upon drying, even after exposure to organic solvents. In addition, metal oxide microparticles (e.g., SiO2) are thought to add available bonding sites to the oxide that can bond (covalent or ionic) and / or interact (e.g., van der Waals forces, hydrogen bonds, etc.) with the ink binder and / or pigment molecules in the ink. This bonding and / or interaction between the molecules of the ink composition and the oxide microparticles may improve the durability of the ink printed on a printable surface.

[0038] Inorganic particles may have an average diameter on the micrometer (micron or μm) scale, such as about 1 μm to about 20 μm. Such fine particles may be sufficiently smooth on the exposed surface while still providing a sufficiently large surface area to interact with the ink composition applied to the printable coating. In addition, fine particles that are too large may result in a grainy image on the printable coating and / or reduce the sharpness of any image applied thereto. In a particular embodiment, the printable coating may comprise a first plurality of inorganic fine particles having a first average diameter and a second plurality of inorganic fine particles having a second average diameter, where the first average diameter is smaller than the second average diameter. For example, the first average diameter may be about 1 μm to about 10 μm (e.g., about 4 to about 6), and the second average diameter may be about 8 μm to about 20 μm (e.g., about 8 to about 10, such as about 8 to about 9).

[0039] The printable barrier coating may contain inorganic particles in amounts less than 40% by weight of the printable barrier coating (e.g., less than 35% by weight, less than 30% by weight, less than 25% by weight, less than 20% by weight, less than 15% by weight, less than 12% by weight, less than 10% by weight, less than 8% by weight, less than 5% by weight, less than 3% by weight, or less than 2% by weight).

[0040] In some embodiments, the printable barrier coating may contain additives such as thickeners, dispersants, emulsifiers, viscosity modifiers, humectants, pH modifiers, initiators, stabilizers, chain transfer agents, buffers, salts, preservatives, flame retardants, wetting agents, protective colloids, biocides, corrosion inhibitors, crosslinking agents, crosslinking accelerators, and lubricants. In some embodiments, the printable barrier coating may contain one or more dyes and / or coloring pigments for producing colored or patterned paper or for changing the shade of paper. Exemplary dyes include basic dyes, acid dyes, anionic direct dyes, and cationic direct dyes. Exemplary coloring pigments include organic and inorganic pigments in the form of anionic and cationic pigment dispersions. Additives may be included in any amount, such as up to about 5% by weight (e.g., about 0.1% to about 1% by weight).

[0041] As mentioned, crosslinking agents may be present in the printable barrier coating to ensure that a highly crosslinked coating is formed. In particular, water-based polymers can react with crosslinking agents to form three-dimensional crosslinked materials. Particularly preferred crosslinking polymer binders include those containing reactive carboxyl groups. Exemplary crosslinking binders containing carboxyl groups include acrylics, polyurethanes, and ethylene-acrylic acid copolymers. Other desirable crosslinking binders include those containing reactive hydroxyl groups. Crosslinking agents that can be used to crosslink binders containing carboxyl groups include polyfunctional aziridines, epoxy resins, carbodiimides, and oxazoline-functional polymers. Crosslinking agents that can be used to crosslink binders containing hydroxyl groups include melamine-formaldehyde, urea-formaldehyde, amine-epichlorohydrins, and polyfunctional isocyanates.

[0042] A crosslinking catalyst may also be present in the printable barrier coating to help ensure sufficient crosslinking during curing. For example, the crosslinking catalyst may be an imidazole curing agent. However, in certain embodiments, the coating may not contain such a crosslinking catalyst.

[0043] When the printable barrier coating is intended for applications involving the acceptance of dye-based inks via inkjet printing, the printable coating may further contain a cationic polyvalent electrolyte to function as a cationic dye fixative. If present, the printable coating may contain about 0.1% to about 5% by weight of the cationic dye fixative.

[0044] The printable barrier coating is, in some embodiments, 2 g / m² 2 (For example, 3 g / m 2 More than 4g / m 2 More than 5g / m 2 More than 6g / m 2 More than 7g / m 2 More than 8g / m 2 More than 9g / m 210 g / m or more 2 11 g / m or more 2 12 g / m or more 2 13 g / m or more 2 14 g / m or more 2 15 g / m or more 2 16 g / m or more 2 17 g / m or more 2 18 g / m or more 2 19 g / m or more 2 20 g / m or more 2 or 25 g / m or more 2 It may have a coating weight of (or more). The printable barrier coating, in some embodiments, is 25 g / m 2 or less (e.g., 24 g / m 2 or less, 23 g / m 2 or less, 22 g / m 2 or less, 21 g / m 2 or less, 20 g / m 2 or less, 19 g / m 2 or less, 18 g / m 2 or less, 17 g / m 2 or less, 16 g / m 2 or less, 15 g / m 2 or less, 14 g / m 2 or less, 13 g / m 2 or less, 12 g / m 2 or less, 11 g / m 2 or less, 10 g / m 2 or less, 9 g / m 2 or less, 8 g / m 2 or less, 7 g / m 2 or less, 6 g / m 2 or less, 5 g / m 2 or less, 4 g / m 2 or 3 g / m or less 2 It may have a coating weight of (or less). The printable barrier coating, in some embodiments, is 2 g / m 2 ~20 g / m 2 (e.g., 5 g / m 2 ~20 g / m 2 , 2 g / m 2 ~15 g / m 2 , or 5 g / m 2 ~12 g / m 2The coating weight may be 1 / 2. The coating weight can be reported in grams of coating per square meter of cellulosic substrate and can be directly calculated from the amount of coating applied and the surface area of ​​the cellulosic substrate to which the coating is applied.

[0045] The printable barrier coating may have a thickness of 0.5 mil or more (e.g., 0.6 mil or more, 0.7 mil or more, 0.8 mil or more, 0.9 mil or more, 1 mil or more, 1.1 mil or more, 1.2 mil or more, 1.3 mil or more, 1.4 mil or more, 1.5 mil or more, 1.6 mil or more, 1.7 mil or more, 1.8 mil or more, 1.9 mil or more). In some embodiments, the printable barrier coating has a thickness of 2 mil or less (e.g., 1.9 mil or less, 1.8 mil or less, 1.7 mil or less, 1.6 mil or less, 1.5 mil or less, 1.4 mil or less, 1.3 mil or less, 1.2 mil or less, 1 mil or less, 0.9 mil or less, 0.8 mil or less, 0.7 mil or less, or 0.6 mil or less). In some embodiments, the printable barrier coating has a thickness of 0.5 mil to 2 mil (e.g., 0.9 mil to 1.6 mil, 1.1 mil to 1.4 mil). The thickness of the coating may be calculated based on the density of the coating and the weight of the coated paper.

[0046] Surface treatment In many cases, barrier coatings have good structural and other characteristics, but due to their surface characteristics, they do not have sufficient printability or adhesive properties. Treatment may be necessary to alter the surface of paper and other materials to make them more receptive to adhesives or printing inks. In some embodiments, barrier coatings can be oxidized, smoothed, or a combination thereof to improve adhesion. In some embodiments, surface treatment may include high-energy discharge, e.g., ionization discharge and / or thermal discharge. As used herein, “high-energy discharge” refers to an energy source that can alter molecular bonds and / or energy on the surface of a material. In some embodiments, the energy source can break molecular bonds on the surface of the material. The broken bonds are then free to bond to free radicals and other particles present in the high-energy discharge environment. In some embodiments, barrier coatings can be surface-treated (e.g., physical surface treatment or thermal treatment) using a process selected from corona treatment, plasma discharge treatment, flame treatment, or a combination thereof. Surface treatment of water-based polymer coatings can improve, for example, thermal sealing and / or surface adhesion between cellulosic substrate layers.

[0047] Corona treatment involves a discharge process that generates ozone, which in turn oxidizes the substrate surface, creating polar sites that contribute to the formation of strong bonds. The treatment level is measured in dynes. (Currently not recommended) In the CGS unit system, a dyne is the force required to accelerate one gram of mass at one centimeter per second squared. (1 dyne = 1 × 10⁻¹⁶) 5 (Newton). Therefore, in packaging, it is used as a measure of surface energy or surface polarity. The dyne level is an indicator of the ability of a surface to wet with a liquid and form a chemical bond with an adhesive, coating, or ink. The dyne level of a surface should typically be 37 or higher, depending on the properties of the adhesive material (ASTM D2578).

[0048] In some embodiments, the barrier coating is corona-treated at a suitable power level. The barrier coating may be corona-treated at a power level of 1 watt or more. In some embodiments, the barrier coating is corona-treated at a power level of 1 to 4 watts per square foot per minute (e.g., 2 watts or more, 2.5 watts or more, 3 watts or more, or 3.5 watts or more). In some embodiments, the barrier coating is corona-treated at 4 watts or less (e.g., 3.5 watts or less, 3 watts or less, 2.5 watts or less, or 2 watts or less). In some embodiments, the barrier coating is corona-treated at 2 to 4 watts per square foot per minute. The exposure time of the barrier coating on the cellulose substrate to corona treatment can be very short. For example, the exposure time may be less than 1 second. In some embodiments, corona treatment may be carried out on a movable paper substrate web running on a coating line. In some embodiments, the barrier coating may be corona-treated on a coating line using a line speed of 100 ft / min or more. For example, the barrier coating may be corona-treated using line speeds of 500 ft / min to 5000 ft / min, such as 500 ft / min to 1000 ft / min.

[0049] An increase in surface energy can enhance the wettability and adhesive properties of the surface. If the watt density required to bring a water-based polymer coating to a specific dyne level is determined, it can be used to predict the consequences of changes in parameters such as line speed (if any).

[0050] Backside coating In some embodiments, the cellulosic substrate has high dimensional stability with reduced tendency to bend. In some embodiments, the film-forming polymer can be coated on the back side of the cellulosic substrate (the surface opposite the side with the barrier coating). Preferably, the film-forming polymer is bio-based, and at least 80% by weight of the polymer film is obtained from non-petroleum or bio-renewable raw materials.

[0051] Examples of film-forming polymers that can reduce curvature include polyvinyl alcohol (PVOH), polyvinylamines, alginates, polyester elastomers, and natural polymers (e.g., starch, gum, cellulose, carboxymethylcellulose).

[0052] The back coating is 0.2 g / m² in some embodiments. 2 (For example, 0.3 g / m 2 More than 0.4g / m 2 More than 0.5g / m 2 More than 0.6g / m 2 More than 0.7g / m 2 More than 0.8g / m 2 More than 0.9g / m 2 More than 1.0g / m 2 More than 1.1g / m 2 More than 1.2g / m 2 More than 1.3g / m 2 More than 1.4g / m 2 More than 1.5g / m 2 More than 1.6g / m 2 More than 1.7g / m 2 More than 1.8g / m 2 More than 1.9g / m 2 More than 2.0g / m 2 More than 2.1g / m 2 More than 2.2g / m 2 More than 2.3g / m 2 More than 2.4g / m 2 More than 2.5g / m 2 More than 2.6g / m 2 More than 2.7g / m 2 More than 2.8g / m 2 Above, or 2.9 g / m² 2 The coating may have a weight of the above. In some embodiments, the back coating is 5.0 g / m². 2 (For example, 3.0 g / m²) 2 Below 2.8g / m 2 Below 2.7g / m 2 Below, 2.6g / m 2 Below 2.5g / m 2 Below 2.4g / m 2 Below, 2.3g / m2 Below, 2.2g / m 2 Below, 2.1g / m 2 Below 2.0g / m 2 Below, 1.9g / m 2 Below 1.8g / m 2 Below 1.7g / m 2 Below 1.6g / m 2 Below 1.5g / m 2 Below 1.4g / m 2 Below 1.3g / m 2 Below 1.2g / m 2 Below, 1.1g / m 2 Below 1.0g / m 2 Below, 0.9g / m 2 Below 0.8g / m 2 Below, 0.7g / m 2 Below 0.6g / m 2 Below 0.5g / m 2 Below, 0.4g / m 2 less than or equal to 0.3g / m 2 The coating may have the following weights. In some embodiments, the back coating is 0.2 g / m². 2 ~3.0g / m 2( For example, 0.5 g / m 2 ~2.8g / m 2 , or 1.0 g / m 2 ~2.5g / m 2) It may have a coating weight of [weight].

[0053] Printable paper, protective transport bags, and packaging containers As described herein, the printable paper of this disclosure is repulpable. The repulping process refers to any mechanical action that disperses dry pulp fibers in an aqueous pulp fiber suspension. The conditions for repulping, as well as the equipment used commercially, are in accordance with the Fiberboard Association Voluntary Standard for Repulping and Recycling Corrugated Fiberboard Treated to Improve its Performance in the Presence of Water and Water Vapor August 16, 2013: Appendix A: Repulpability (this reference is incorporated herein by reference in its entirety).

[0054] In some embodiments, printable paper may be repulpable in accordance with the Fiberboard Association Voluntary Standard for Repulping and Recycling Corrugated Fiberboard Treated to Improve its Performance in the Presence of Water and Water Vapor August 16, 2013:Appendix A:Repulpability.

[0055] Using the additional components described herein, printable paper can be 120 lbs / 3000 ft. 2 It can be manufactured with strength characteristics that are very suitable for commercial protective bag applications, having the following basis weights. For example, printable paper can be 118 lbs / 3000 ft. 2 The following basis weights (for example, 115 lbs / 3000 ft) 2 Below, 110lbs / 3000ft 2 Below: 105 lbs / 3000 ft 2 Below, 100 lbs / 3000 ft 2 Below: 95 lbs / 3000 ft 2 Below: 90 lbs / 3000 ft 2Below, 85lbs / 3000ft 2 Below: 80 lbs / 3000 ft 2 Below, 75lbs / 3000ft 2 Below, 70lbs / 3000ft 2 Below: 65 lbs / 3000 ft 2 Below 60lbs / 3000ft 2 Below: 55 lbs / 3000 ft 2 The following, or 50 lbs / 3000 ft 2 The following may be present. In some embodiments, the printable paper is 45 lbs / 3000 ft. 2 (For example, 50 lbs / 3000 ft) 2 Above 55 lbs / 3000 ft 2 Above 60 lbs / 3000 ft 2 Above 65 lbs / 3000 ft 2 Above 70 lbs / 3000 ft 2 Above 75 lbs / 3000 ft 2 Above 80 lbs / 3000 ft 2 Above 85 lbs / 3000 ft 2 Above 90 lbs / 3000 ft 2 Above 95 lbs / 3000 ft 2 Above, 100 lbs / 3000 ft 2 Above 105 lbs / 3000 ft 2 Above 110 lbs / 3000 ft 2 lbs / 3000ft 2 Above 115 lbs / 3000 ft 2 Above, or 120 lbs / 3000 ft 2 The paper has a basis weight of 50 lbs / 3000 ft. In some embodiments, the printable paper has a basis weight of 50 lbs / 3000 ft. 2 ~120lbs / 3000ft 2 (For example, 60 lbs / 3000 ft) 2 ~120lbs / 3000ft 2 70 lbs / 3000 ft 2 ~110 lbs / 3000 ft 2 70 lbs / 3000 ft 2 ~100lbs / 3000ft 2 , or 75lbs / 3000ft2 ~100lbs / 3000ft 2 It has a basis weight of ).

[0056] The printable paper is 20 g / m², as determined by TAPPI T441. 2 It may exhibit a 2-minute cob sizing value of less than 2 minutes. For example, printable paper is 20 g / m². 2 The following 2-minute cob sizing values ​​(e.g., 19 g / m²) 2 Below 18g / m 2 Below, 17g / m 2 Below 16g / m 2 Below 15g / m 2 Below, 14g / m 2 Below 13g / m 2 Below, 12g / m 2 Below, 11g / m 2 Below 10g / m 2 Below, 9g / m 2 Below, 8g / m 2 Below, 7g / m 2 Below 6g / m 2 Below, 5g / m 2 Below, 4g / m 2 Less than or equal to 3g / m 2 The following may be observed. Printable paper is 0.2 g / m². 2 ~20g / m 2 (For example, 0.2g / m 2 ~18g / m 2 , 0.2g / m 2 ~15g / m 2 , or 2g / m 2 ~10g / m 2 ) 20g / m² as determined by TAPPI T441 2 It may exhibit a 2-minute cob sizing value of less than 2 minutes.

[0057] Printable paper may exhibit a tensile strength (MD) of at least 45 lbf / in (e.g., at least 45 lbf / in, at least 55 lbf / in, or at least 65 lbf / in) or at least 70 lbf / in (e.g., at least 70 lbf / in, at least 80 lbf / in, at least 90 lbf / in, at least 100 lbf / in, at least 110 lbf / in, at least 120 lbf / in, at least 130 lbf / in, at least 140 lbf / in, at least 150 lbf / in, at least 160 lbf / in, at least 170 lbf / in, at least 180 lbf / in, at least 190 lbf / in, or at least 200 lbf / in) as determined by TAPPI T494.

[0058] Printable paper may exhibit a tensile strength (CD) of at least 30 lbf / in (e.g., at least 30 lbf / in, at least 40 lbf / in, at least 50 lbf / in, at least 60 lbf / in, at least 70 lbf / in, at least 80 lbf / in, at least 90 lbf / in, at least 100 lbf / in, at least 110 lbf / in, or at least 120 lbf / in) as determined by TAPPI T494.

[0059] Printable paper is determined by TAPPI T494, with a minimum load capacity of 200 J / m². 2 (For example, at least 210 J / m 2 at least 215 J / m 2 at least 220 J / m³ 2 at least 230 J / m³ 2 at least 240 J / m³ 2 at least 250 J / m³ 2 at least 260 J / m³ 2 at least 270 J / m³ 2 at least 280 J / m³ 2 at least 290 J / m³ 2 , or at least 300 J / m 2 It may exhibit tensile energy absorption (MD).

[0060] Printable paper is determined by TAPPI T494, with a minimum load capacity of 340 J / m². 2 (For example, at least 345 J / m 2 at least 350 J / m³ 2 at least 355 J / m 2 at least 360 J / m³ 2 at least 365 J / m 2 at least 370 J / m³ 2 at least 375 J / m 2 at least 380 J / m³ 2 at least 385 J / m 2 at least 390 J / m³ 2 at least 395 J / m 2 at least 400 J / m³ 2 , or at least 405 J / m 2 It may exhibit tensile energy absorption (CD) of the following magnitude.

[0061] Printable paper may exhibit a tear resistance (MD) of at least 170 gf (e.g., at least 175 gf, at least 180 gf, at least 190 gf, at least 200 gf, at least 210 gf, at least 215 gf, at least 220 gf, at least 230 gf, at least 235 gf, at least 240 gf, at least 250 gf) as determined by TAPPI T414.

[0062] Printable paper may exhibit a tear resistance (CD) of at least 180 gf (e.g., at least 185 gf, at least 190 gf, at least 195 gf, at least 200 gf, at least 205 gf, at least 210 gf, at least 215 gf, at least 220 gf, at least 225 gf, at least 230 gf, at least 235 gf) as determined by TAPPI T414.

[0063] Printable paper is defined by its tensile strength (N / m) and basis weight (g / m²). 2It can exhibit a tensile index (MD) of 70-95 Nm / g (e.g., 75 Nm / g-90 Nm / g, 80 Nm / g-88 Nm / g, or 82 Nm / g-86 Nm / g), defined by dividing by ).

[0064] Printable paper is defined by its tensile strength (N / m) and basis weight (g / m²). 2 It can exhibit a tensile index (CD) of 40-60 Nm / g (e.g., 45 Nm / g-55 Nm / g or 47 Nm / g-51 Nm / g), defined by dividing by ).

[0065] The first surface, the second surface, or both of the printable paper may exhibit a surface energy of 37 dynes / cm to more than 60 dynes / cm (e.g., more than 37 dynes / cm, more than 40 dynes / cm, more than 45 dynes / cm, more than 50 dynes / cm, or more than 55 dynes / cm, or 37 dynes / cm to 45 dynes / cm, or 40 dynes / cm to 45 dynes / cm).

[0066] Printable paper can be used to make protective bags for transport. In some embodiments, the protective bag for transport can be obtained from the printable paper disclosed herein. In some embodiments, the entire protective bag for transport can be obtained from the printable paper. In further embodiments, the protective bag for transport may be an envelope.

[0067] Printable paper can be used to make reusable and flexible packaging containers, and at least part or all of the packaging container may be made from printable paper. Reusable and flexible packaging containers may be protective bags for transport, such as envelopes. For example, provided herein is a reusable and flexible packaging container including an inner surface that defines the volume of the product, the inner surface being made from a cellulosic substrate as described herein, and the outer surface facing the inner surface having a surface energy greater than 37 dynes / cm.

[0068] Reusable and flexible packaging containers are preferably reusable in a single stream, such as general waste recycling. For example, reusable and flexible packaging containers are repulpable in accordance with the Fiberboard Association Voluntary Standard for Repulping and Recycling Corrugated Fiberboard Treated to Improve its Performance in the Presence of Water and Water Vapor August 16, 2013:Appendix A:Repulpability.

[0069] These and other modifications and variations of the present invention can be implemented by those skilled in the art without departing from the spirit and scope of the invention as specifically described in the appended claims. In addition, it should be understood that the various embodiments may be interchangeable in whole or in part. Furthermore, those skilled in the art will understand that the foregoing description is for illustrative purposes only and is not intended to limit the invention as further described in the appended claims. [Examples]

[0070] Example 1: Protective bag Conventional fiber-based protective bags do not offer protection from water penetration, compromising durability and increasing the likelihood of product damage. Furthermore, these products are generally manufactured from poor-quality fibers, resulting in a poor strength / basis weight ratio. Thus, durability is achieved at the expense of increased protective bag weight, which is a critical consideration for many brands. This embodiment provides a material for packaging containers that can meet the stringency of commercial transport (such as for apparel) while offering a sustainable alternative to plastic-based materials with a more competitive basis weight than currently available fiber-based products, and providing novel performance advantages.

[0071] Premium protective bag base stock Several coated protective bag base stocks may be manufactured according to Table 1 or according to the parameters defined in Tables 2-5. The base stocks were manufactured using a fiber feed containing 50% consumer waste (PCW) and 50% Northern bleached coniferous kraft paper (NBSK) composed primarily of (>75%) black spruce fibers, following a standard papermaking procedure. A combination of cationic starch and anionic polyacrylamide dry strength resin (Hercobond2000) was added to the wet side of the papermaking machine. Calendering was not required.

[0072] Following the production of the base paper, a functional coating was applied to one or both sides of the base paper. The topcoat (wire side) was a barrier coating with a coat weight ranging from 5.0 to 12.0 gsm. Using an air knife pressure of approximately 3 psi, a 2% PVOH back-side (felt side) coating was applied to provide a flat and warp-free web. Standard coating application and drying conditions were maintained to achieve optimal barrier properties. [Table 1]

[0073] Table 2 shows the results of Trial 1 from base stock manufacturing. [Table 2]

[0074] Table 3 shows the results of trials 1-5 from coated base stocks. [Table 3]

[0075] Table 4 shows the characteristics of the results from trials 1-4 using coated base stocks. [Table 4-1] [Table 4-2]

[0076] Repulpability test In accordance with the Voluntary Standard For Repulping and Recycling Corrugated Fiberboard Treated to Improve Its Performance in the Presence of Water and Water Vapor August 16, 2013: Appendix A: Repulpability, FBA repulpability tests were performed on four coated paper samples. Samples were conditioned and tested under TAPPI standard conditions. Samples were prepared at 1 inch x 4 inch, and several shorter portions were used to obtain an initial fill of 25 oven-dry grams. Tap water was used for repulping and screening. Oven-dry weights were used for the initial fill, as well as for acceptable and rejected samples. Samples were screened for 20 minutes through a 0.010-inch slotted valley screen. Acceptable samples were screened using a 150-mesh T316 alloy stainless steel screen with an opening width of 0.0041 inches.

[0077] The results from the repulping feasibility test are summarized in Table 5 below. [Table 5]

[0078] Results: At 34 dynes / cm, the surface energy of the base stock was too low for the water-based inks typically used in flexographic printing processes on paper cones, resulting in insufficient ink absorption, drying defects, and excessive back-printing. The optimal range for surface energy was estimated to be 40–45 dynes / cm.

[0079] As a result of applying the barrier coating to a single surface (C1S), the coated base stock exhibited CD orientation curvature. This caused the central seam of the original protective bag to tear. This was ultimately corrected by the compression inherent in the carton packaging.

[0080] The pressure-sensitive adhesive used to seal the envelope did not bond securely to the coated surface of the protective bag base stock. As a result, tearing of the fibers upon opening the protective bag was not achieved. This is a feature that would be obvious to most customers as evidence of tampering. Similar to printing difficulties, this defect is thought to be due to low surface energy and can be corrected by increasing the surface energy of the coating.

[0081] The compositions and methods of the appended claims are not limited by the specific compositions and methods described herein, but are intended as examples of several aspects of the claims, and any functionally equivalent compositions and methods are intended to fall within the claims. In addition to those shown and described herein, various modifications of compositions and methods are intended to fall within the claims. Furthermore, while only specific representative compositions and method steps disclosed herein are specifically described, other combinations of compositions and method steps are also intended to fall within the claims, even if not specifically enumerated. Thus, combinations of steps, elements, components, or components are included, whether explicitly mentioned herein or not, and even if not explicitly mentioned. Where used herein, the term “equips” and its variations are used synonymously with the term “includes” and its variations, and are open and non-restrictive terms. While the terms “comprising” and “including” are used herein to describe various embodiments, the terms “essentially consisting of” and “consisting of” may be used instead of “comprising” and “including” to provide more specific embodiments of the invention, and these are also disclosed. Except in the examples, or as otherwise described, all numbers used herein and in the claims to represent quantities of components, reaction conditions, etc., should be understood, at a minimum, in terms of significant figures and the usual rounding approach, and not intended to limit the application of the principle of equivalence to the claims.

Claims

1. Printable paper, A cellulose-based substrate having a first surface and a second surface facing the first surface, and The cellulosic substrate includes a printable barrier coating on the first surface, The printable barrier coating is obtained from an aqueous polymer, The printable barrier coating is surface-treated with high-energy discharge. The aforementioned printable paper is 20 g / m² ２ Having a 2-minute Cob sizing value of less than, A printable paper wherein the first surface, the second surface, or both have a surface energy greater than 37 dynes / cm.

2. The printable paper according to claim 1, wherein the printable paper is repulpable in accordance with the Fiberboard Association Voluntary Standard for Repulping and Recycling Corrugated Fiberboard Treated to Improve its Performance in the Presence of Water and Water Vapor August 16, 2013: Appendix A: Repulpability.

3. Determined by TAPPI T494, at least 45 lb ｆ / in or at least 70lb ｆ A printable paper according to claim 1 or 2, exhibiting a tensile strength (MD) of 1 / in.

4. 120lbs / 3000ft ２ Below, or 60 lbs / 3000 ft ２ ~120lbs / 3000ft ２ A printable paper according to any one of claims 1 to 3, having the basis weight.

5. The aforementioned printable paper is 15 g / m² ２ Printable paper according to any one of claims 1 to 4, having a cob sizing value of less than 2 minutes.

6. The printable paper according to any one of claims 1 to 5, wherein the first surface, the second surface, or both have a surface energy of 40 dynes / cm to 45 dynes / cm.

7. The printable paper is determined by TAPPI T494 to have a density of at least 200 J / m². ２ A printable paper according to any one of claims 1 to 6, exhibiting a tensile energy absorption (MD) of the following:

8. The printable paper according to any one of claims 1 to 7, wherein the printable paper exhibits a tear resistance (MD) of at least 170 gf as determined by TAPPI T414.

9. The printable paper according to any one of claims 1 to 8, wherein the cellulose-based substrate includes a drying strength additive, and the drying strength additive includes cationic starch and polyacrylamide resin.

10. The printable paper according to any one of claims 1 to 9, wherein the printable barrier coating is surface-treated using corona treatment.

11. The printable paper according to any one of claims 1 to 10, wherein the aqueous polymer comprises an acrylic homopolymer, an acrylic copolymer, a polyester acrylic copolymer, a vinyl acrylic copolymer, a wax emulsion, or a combination thereof.

12. The printable blocking coating is 2 g / m ２ to 20 g / m ２ , 2 g / m ２ to 15 g / m ２ or 5 g / m ２ to 12 g / m ２ and has a coating weight of, the printable paper according to any one of claims 1 to 11.

13. The printable paper according to any one of claims 1 to 12, wherein the printable barrier coating further comprises inorganic particles.

14. The inorganic particles, The printable paper according to claim 13, which is surface-treated, contains silica, or both.

15. The tensile strength (N / m) determined by TAPPI T494 is expressed as basis weight (g / m²). ２ The printable paper according to any one of claims 1 to 14, wherein the tensile index (MD), defined by dividing by ), is 70 to 95 Nm / g.

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