HK40099201A - Enhanced cellulose nanofibrils (cnf) - Google Patents

Description

Improved cellulose nanofibers (CNF)

Technical Field

This disclosure relates to improved cellulose nanofibers (CNF) (or improved CNF binders), methods for manufacturing improved CNF binders, methods for manufacturing wet-laid, dry-laid, or molded articles by mixing improved CNF with ingredients in the wet end of a papermaking process using improved CNF binders, methods for coating cellulose-based materials, intermediate-formed fiber articles, and/or molded articles using improved CNF binders, and cellulose-based articles obtained by all of these methods, wherein the improved CNF comprises sugar fatty acid esters, glycerides, fatty acid salts, natural waxes, and/or cellulose crosslinking agents (SGF) blends bound to the CNF.

Background Technology

Cellulose materials have wide applications in industry as fillers, absorbents, and printing components. Their superior use compared to materials from other sources is due to their high thermal stability, good oxygen barrier properties, and chemical/mechanical elasticity (see, for example, Aulin et al., Cellulose (2010) 17: 559-574; the full text of which is incorporated herein by reference). Closely related is the fact that these materials are completely biodegradable once released into the environment and are entirely non-toxic. In applications such as food and disposable product packaging, cellulose and its derivatives are materials of choice for environmentally friendly solutions.

However, many of the advantages of cellulose are offset by the hydrophilic/lipophilic nature of cellulose materials, which exhibit a high affinity for water/fat and are readily hydrated (see, for example, Aulin et al., Langmuir (2009) 25(13): 7675-7685; the full text of which is incorporated herein by reference). While this is beneficial for applications such as absorbents and paper towels, it becomes problematic when the safe packaging of water- and lipid-containing materials, such as food, is required. Long-term storage of food, especially prepared meats containing large amounts of water and/or fat, in cellulose trays, for example, is difficult because the trays will first become wet and then eventually fail. Furthermore, the relatively high porosity of the material on the cellulose surface may necessitate multiple layers of coating to compensate for the inefficiency of maintaining sufficient coating, leading to increased costs.

This problem is typically addressed industrially by coating cellulose fibers with a hydrophobic organic material/fluorocarbon (e.g., perfluoro and polyfluoroalkyl substances (PFAS)), wax, synthetic polymer (e.g., polyethylene), or siloxane. These materials physically protect the underlying hydrophilic cellulose from the water/lipids in its contents, including preventing wicking in the fiber gaps, grease inflow into creases, or allowing the release of the attached material. For example, materials such as PVC/PEI/PE are commonly used for this purpose and are physically attached (i.e., sprayed or extruded) to the surface to be treated.

Because fluorocarbons can reduce the surface energy of products, the industry has used compounds based on fluorocarbon chemistry for many years to produce products with improved resistance to oils and greases. A new problem with the use of perfluorocarbons is their remarkable persistence in the environment. The EPA and FDA have recently begun reviewing the sources, environmental fate, and toxicity of these compounds. A recent study reported a very high prevalence (>90%) of perfluorooctane sulfonates in blood samples taken from school children. The cost of these compounds and their potential environmental liability have prompted manufacturers to seek alternative methods for producing products with resistance to oils and greases.

While lowering surface energy improves the permeability resistance of articles, it also has some drawbacks. For example, textiles treated with fluorocarbons exhibit good stain resistance; however, once soiled, the ability of cleaning compositions to penetrate and thus release dirt from the fabric may be impaired, permanently staining the fabric and reducing its lifespan. Another example is greaseproof paper that will subsequently be printed and/or coated with adhesives. In this case, the necessary grease resistance is achieved through fluorocarbon treatment, but the low surface energy of the paper can lead to problems related to the acceptance of printing inks or adhesives, including abrasion, backing spots, poor adhesion, and registration. If greaseproof paper is used as a pressure-sensitive label with adhesive applied to one side, the low surface energy may reduce adhesive strength. To improve their printability, coatability, or adhesion, low surface energy articles can be treated with post-forming processes such as corona discharge, chemical treatment, flame treatment, etc. However, these processes increase the production cost of the articles and may have other disadvantages.

The goal is to design a hydrophobic, oleophobic, and compostable “green” bio-based coating that allows the coating to remain on the surface of the paper and prevents the core from being drawn into the interfiber gaps of the base paper/film, or reduces the adhesion of the material to the cellulose surface at a lower cost without sacrificing biodegradability and/or recyclability.

Another problem is that conventional coatings used to impart hydrophobic and/or oleophobic barrier properties (including the fluorocarbon and petrochemical coatings mentioned herein) tend to perform poorly at folds, creases, etc., in articles coated with these materials. Specifically, articles typically exhibit poor water and/or grease resistance at these locations. This “grease crease effect” can be defined as the adsorption of grease into the paper structure, with creases created by folding, pressing, or compressing the paper structure. A conventional approach to addressing the grease crease effect is to incorporate latex, polyvinyl alcohol, or similar resins into the coating to improve coating coverage at these locations. However, with this conventional solution, the water and/or oil and grease resistance at these locations may still be inferior to that of flat portions of the article; this conventional solution increases cost due to the addition of resin components; and this conventional solution is not entirely bio-based, as latex and polyvinyl alcohol may be synthetic and/or not easily recyclable.

U.S. Patent Application Publication No. 2018/0066073 (hereinafter referred to as “‘073 Publication’, the entire contents of which are incorporated herein by reference) discloses a tunable method for treating cellulosic materials with a composition that provides enhanced barrier properties, such as water resistance and/or oil and grease resistance (OGR), without sacrificing their biodegradability. In particular, ‘073 Application discloses a method for incorporating sugar fatty acid esters (“SFAEs”) into cellulosic materials to provide treated materials with higher water resistance, grease resistance, barrier function, and other mechanical properties.

U.S. Provisional Patent Application Publication No. 63/022,097, filed May 8, 2020 (hereinafter referred to as the “‘097 application”, the entire contents of which are incorporated herein by reference), discloses a tunable method of treating cellulosic materials with a composition that provides enhanced barrier properties, such as water resistance and/or OGR, without sacrificing their biodegradability. In particular, the ‘097 application discloses a method of combining mixtures of glycerides and/or fatty acid salts. The ‘097 application discloses that barrier formulations comprising mixtures of glycerides and/or fatty acid salts may additionally include SFAEs for imparting water resistance and/or OGR and/or for providing emulsifier functionality.

PCT/US2020/014923 (hereinafter referred to as the “923 application,” the entire contents of which are incorporated herein by reference) discloses a method for treating fibrous cellulosic materials with particles (carrier systems) containing sucrose fatty acid esters, which result in surface modification, including giving such surfaces water resistance and/or oil/grease resistance. The disclosed method provides for combining at least one SFAE with a polymer (e.g., latex) to form micelle particles, and applying such particles to a substrate comprising a fibrous cellulosic base material (e.g., pulp) to form, in particular, molded products. Compositions comprising a combination of SFAE, latex, and optionally minerals or other additives are also disclosed.

US 16/568,953 (hereinafter referred to as the “953 application,” the entire contents of which are incorporated herein by reference) discloses a tunable method for treating cellulosic materials with a barrier coating comprising alcohol-soluble gluten and at least one polyol fatty acid ester, which provides enhanced oil and/or grease resistance to such materials without sacrificing their biodegradability. The disclosed method provides adhesion of the barrier coating to articles comprising articles comprising cellulosic materials and articles manufactured by this method. Materials thus treated exhibit higher oleophobicity and can be used in any application where these properties are required.

US 16/456,499 (hereinafter referred to as the “499 application,” the entire contents of which are incorporated herein by reference) discloses a tunable method for treating cellulosic materials with a barrier coating comprising at least two polyols and/or sugar fatty acid esters, which provides the material with enhanced water, oil, and grease resistance without sacrificing its biodegradability. The disclosed method provides adhesion of the barrier coating to articles comprising articles comprising cellulosic materials and articles manufactured by this method. Materials thus treated exhibit higher hydrophobicity and oleophobicity and can be used in any application requiring these characteristics.

US 16/456,433 (hereinafter referred to as the “433 application,” the entire contents of which are incorporated herein by reference) discloses a method for treating cellulosic materials with a composition that improves the retention of inorganic particles on a cellulosic substrate. The disclosed method provides for combining SFAEs with these inorganic particles and applying this combination to cellulosic materials to eliminate or reduce the use of retention aids or filler binders in papermaking processes. Compositions comprising such a combination of SFAEs and inorganic particles are also disclosed.

The use of adhesives derived from natural sources is also becoming increasingly important for providing “green” bio-based products.

Nanocellulose is a term for cellulose with nanostructures, which can be cellulose nanocrystals (CNC or NCC), cellulose nanofibers (CNF) (also known in the art as cellulose nanofibers and nanofibrated cellulose)), or bacterial nanocellulose.

CNF is a material composed of nanoscale cellulose fibrils, typically with a high aspect ratio (length to width). CNF is usually obtained from natural sources of wood pulp or other cellulose fibers, typically through methods involving subjecting the pulp/fiber to mechanical shear forces.

CNF has been used as a binder in papermaking processes. In this regard, the inventors have determined that using CNF as an additive in wet-end and coating applications can provide improved OGR. However, there are some problems with the use of CNF. One problem is that when CNF is used as a wet-end additive in papermaking formulations, it tends to slow down the rate at which the fiber pad is drained from the pulp (or the dewatering process). This is disadvantageous, for example, because the dewatering rate determines the production speed of cellulose-based products. Another problem is that CNF tends to agglomerate when used as an additive in pulp or spraying agents, which negatively impacts its efficiency and/or its functional properties.

Based on the above overview, there is still a need for “green” bio-based coatings for cellulose-based materials that provide improved water resistance and/or OGR, as well as for “green” cellulose-based molded articles with improved water resistance and/or OGR.

Summary of the Invention

This disclosure provides methods for addressing one or more limitations and/or problems in the aforementioned conventional techniques and/or for providing one or more improvements thereto. However, this disclosure does not aim to address any limitations and/or problems.

In one embodiment, this disclosure relates to an improved cellulose nanofiber binder comprising: cellulose nanofibers (CNF); and an SGF blend bound to the CNF, wherein the SGF blend comprises one or more substances selected from sugar fatty acid esters (SFAE), glycerides, fatty acid salts (“FAS”), natural waxes, and cellulose crosslinking agents.

As used herein, the term "SGF blend" refers to one or more sugar fatty acid esters (SFAEs), and/or one or more glycerides, and/or one or more fatty acid salts (FAS), and/or one or more natural waxes, and/or one or more cellulose crosslinking agents. In some embodiments, the SGF blend used in this disclosure does not include SFAEs; in some embodiments, the SGF blend does not include glycerides; in some embodiments, the SGF blend does not include FAS; in some embodiments, the SGF blend does not include natural waxes; and in some embodiments, the SGF blend does not include cellulose crosslinking agents. In some embodiments, the SGF blend consists essentially of SFAEs, glycerides, and/or FAS. In some embodiments, the SGF blend consists of SFAEs, glycerides, and/or FAS.

The improved cellulose nanofiber binder (or improved CNF) according to this disclosure can provide certain benefits. For example, when used in the wet end of a papermaking process, the improved CNF can maintain or increase the drainage rate of the fiber pad from the pulp. Furthermore, the improved CNF is not subject to the same agglomeration problems as conventional CNF.

In one aspect of this disclosure, the improved cellulose nanofiber binder is substantially composed of CNF and SGF admixtures.

In another aspect of the improved cellulose nanofiber binder, the weight ratio of CNF to SGF admixture is about 1:99 to about 99:1, or about 5:95 to about 95:5, or about 10:90 to about 90:10, or about 15:85 to about 85:15, or about 20:80 to about 80:20, or about 25:75 to about 75:25, or about 30:70 to about 70:30, or about 35:65 to about 65:35, or about 40:60 to about 60:40, or about 45:55 to about 55:45, or about 50:50.

In one embodiment, the improved cellulose nanofiber binder is obtained by a method comprising the following steps: obtaining an aqueous mixture of cellulose nanofibers (CNF); obtaining an aqueous SGF blend; and mixing the aqueous CNF mixture with the aqueous SGF blend to obtain a CNF/SGF blend. The mixing of CNF with the SGF blend (and thereby contacting the CNF with the SGF blend) is sufficient to allow the SGF blend to bind to the CNF. Alternatively, the SGF blend can bind to the CNF by exposing the CNF/SGF mixture to heat, radiation, a catalyst, or a combination thereof for a sufficient period of time. The method may also include a step of reducing the water content of the CNF/SGF mixture, for example, by draining the water.

In one embodiment, the improved cellulose nanofiber binder according to the present disclosure is obtained by a method comprising the following steps: obtaining an aqueous mixture of cellulose pulp (e.g., wood pulp); obtaining an aqueous SGF blend; mixing the aqueous mixture of cellulose pulp with the aqueous SGF blend to obtain a cellulose/SGF mixture; subjecting the cellulose/SGF mixture to mechanical shear force to obtain the improved cellulose nanofiber binder.

In one aspect, methods for obtaining improved CNF may also include a step of reducing the water content of the cellulose/SGF mixture, for example, by draining the water.

In one aspect, the method for obtaining improved CNF may further include pretreating the cellulose pulp before obtaining the cellulose/SGF blend and/or before subjecting the cellulose/SGF blend to mechanical shear forces.

In one aspect, the pretreatment may include lowering the pH of an aqueous mixture of cellulose pulp by adding acid.

In one embodiment, this disclosure provides a barrier formulation comprising an improved CNF according to this disclosure. The composition of the barrier formulation can be selected to variably derive cellulose-based materials by methods known in the art (e.g., those disclosed in '073' or '097').

In one embodiment, this disclosure provides a method for manufacturing a cellulose-based article, the method comprising: adding an improved cellulose nanofiber binder according to this disclosure to an aqueous papermaking batch; and draining water from the batch to obtain a fiber web.

In one aspect, the method further includes molding the fiber web into a molded article having a three-dimensional shape.

In one embodiment, a method for imparting barrier properties to a cellulose-based material is provided, the method comprising contacting the cellulose-based material with an aqueous barrier agent for imparting barrier properties, the barrier agent comprising an improved cellulose nanofiber binder according to the present disclosure; and bonding the barrier agent to a surface of the cellulose-based material to obtain a bonded cellulose-based material having barrier properties, wherein the barrier properties are selected from one or more of water resistance, grease resistance, and gas resistance.

In one embodiment, a barrier formulation is provided, the barrier formulation comprising an improved cellulose nanofiber binder according to the present disclosure; a second SGF blend comprising one or more sugar fatty acid esters (SFAEs), one or more glycerides and/or one or more fatty acid salts; and water.

In one aspect, a second SGF blend of the blocking agent can be selected to tunably derive a cellulose-based material by methods known in the art (e.g., those disclosed in '073 or '097).

In one aspect, the barrier formulations disclosed herein may include pigments conventionally used in the papermaking industry.

In one embodiment, a method for imparting barrier properties to a cellulose-based material includes: contacting the cellulose-based material with a barrier agent for imparting barrier properties, the barrier agent comprising (a) cellulose nanofibers (CNF) and (b) an SGF blend; and binding the barrier agent to the surface of the cellulose-based material to obtain a bound cellulose-based material with barrier properties, wherein the barrier properties are selected from one or more of water resistance, grease resistance, and gas barrier properties.

The method for imparting barrier properties according to this disclosure can provide the same benefits as described above, including maintaining or increasing the drainage rate when the method is applied to a wet-end process, and preventing CNF aggregation.

In one aspect, when the total weight of the barrier agent used in the method of imparting barrier properties according to this disclosure is considered to be 100% by weight, the barrier agent comprises about 4% to about 96% by weight of CNF and about 4% to about 96% by weight of SGF admixture.

In one aspect, the cellulose-based material used in the method for imparting barrier properties according to this disclosure includes cellulose fibers, and the contact step includes forming an aqueous mixture of the barrier agent and the cellulose fibers.

In one aspect, the SGF blend may be present in the aqueous mixture or dispersion at a total concentration of at least 0.025% (by weight) of the total cellulose fibers present in the aqueous mixture.

In one respect, aqueous mixtures include one or more pigments commonly used in the paper industry.

In one aspect, the aqueous mixture is in the form of a slurry having a solid content of about 0.1 to 10.0% by weight, 0.1 to 6.0% by weight, or about 0.1 to 2.0% by weight, or about 0.2 to 1.5% by weight.

In one aspect, the method also includes reducing the water content of the aqueous mixture, for example by draining the water.

In another aspect, the contact step in the method for imparting barrier properties according to this disclosure includes coating the surface of a cellulose-based substrate with a formulation by means of impregnation, spraying, smearing, printing, or any combination of these methods.

In one respect, the SGF dopant is present on the substrate surface at a weight of at least about 0.05 g/ ^m² .

There are no particular limitations on the cellulose-based substrate. In one aspect, examples of cellulose-based substrates include surfaces selected from articles containing: paper, cardboard, bacon boards, insulating materials, pulp, cartons for food storage, compost bags, bags for food storage, release paper, transport bags, fabrics or films that prevent/block grass, mulch films, flower pots, packaging beads, bubble wrap outer packaging, oil-absorbing materials, laminates, envelopes, gift cards, credit cards, gloves, raincoats, OGR paper, shopping bags, diapers, diaphragms, tableware, tea bags, containers for coffee or tea, containers for holding hot or cold beverages, cups, plates, bottles for storing carbonated liquids, bottles for storing non-carbonated liquids, caps, food packaging films, waste disposal containers, food handling tools, textile fibers, water storage and transportation equipment, storage and transportation equipment for alcoholic or non-alcoholic beverages, casings or screens for electronic products, internal or external components of furniture, curtains, interior decoration, fabrics, films, boxes, sheets, trays, pipes, water pipes, clothing, medical devices, pharmaceutical packaging, contraceptives, camping equipment, molded cellulose materials, and combinations thereof.

In one aspect, the method for imparting barrier properties according to this disclosure provides a combined cellulose-based material having a water contact angle equal to or greater than 90°.

In one aspect, the method for imparting barrier properties according to this disclosure provides a combined cellulose-based material that exhibits a TAPPI T 559KIT test value of 3 to 12.

In one aspect, the method for imparting barrier properties according to this disclosure provides a combined cellulose-based material that exhibits a water contact angle equal to or greater than 90° and/or a TAPPI T 559KIT test value of 3 to 12 in the absence of any second hydrophobic material.

In one embodiment, a method for manufacturing an improved cellulose nanofiber binder is provided, the method comprising: obtaining an aqueous mixture of cellulose nanofibers (CNF); obtaining an aqueous SGF blend; and mixing the aqueous CNF mixture with the aqueous SGF blend to obtain a CNF/SGF mixture and binding the SGF blend to the CNF.

In one aspect, methods for producing improved CNF also include reducing the water content of the CNF/SGF mixture.

In one embodiment, a method for manufacturing an improved cellulose nanofiber adhesive is provided, the method comprising: obtaining an aqueous mixture of cellulose pulp; obtaining an aqueous SGF blend; mixing the aqueous mixture of cellulose pulp with the aqueous SGF blend to obtain a cellulose/SGF mixture; subjecting the cellulose/SGF mixture to mechanical shear forces to obtain the improved cellulose nanofiber adhesive.

In one aspect, the method includes pretreating the cellulose pulp before obtaining the cellulose/SGF mixture and/or before subjecting the cellulose/SGF mixture to mechanical shear forces.

In one embodiment, a method of manufacturing a molded article is disclosed, the method comprising: providing a forming tool having a three-dimensional shape (the three-dimensional shape having a forming portion), contacting the forming portion with a cellulose composition such that the forming portion is covered by a wet pulp layer; and dewatering the pulp layer on the forming tool to obtain a molded article, wherein the cellulose composition comprises cellulose pulp and an improved cellulose nanofiber binder according to the present disclosure.

In one embodiment, another method of manufacturing a molded article is disclosed, the method comprising: providing a forming tool having a three-dimensional shape (the three-dimensional shape having a forming portion), contacting the forming portion with a cellulose composition such that the forming portion is covered by a wet pulp layer; and dewatering the pulp layer on the forming tool to obtain a molded article, wherein the cellulose composition comprises cellulose pulp and a barrier agent according to the present disclosure.

In one embodiment, another method of manufacturing a molded article is disclosed, the method comprising: providing a forming tool having a three-dimensional shape (the three-dimensional shape having a forming portion), contacting the forming portion with a cellulose composition such that the forming portion is covered by a wet pulp layer; dewatering the pulp layer on the forming tool to obtain an intermediate molded article; and coating the surface of the intermediate molded article with a barrier agent according to the present disclosure by means of impregnation, spraying, smearing, printing or any combination of these methods to obtain the molded article.

In one aspect, the method of manufacturing the molded article includes dehydration at a temperature >100°C to obtain a dry content of at least about 70% by weight, preferably at least about 80% by weight.

In one aspect, the pulp layer present on the forming tool is dehydrated by pressure drying at a temperature >100°C, preferably about 120 to 250°C, or more preferably about 150 to 220°C.

In one aspect, the cellulose composition used in a method for manufacturing a molded article comprises a fiber mixture substantially consisting of chemithermomechanical pulp (CTMP), thermomechanical pulp (TMP), chemical pulp, or semi-chemical pulp, or combinations thereof. The pulp may be bleached or unbleached.

In one aspect, the forming tool is porous or perforated so that water can be removed during the forming process during the dehydration/drying step.

In one aspect, the method of manufacturing the molded article further includes coating the surface of the molded article with a barrier agent containing an SGF admixture by means of dipping, spraying, smearing, printing, or any combination of these methods.

In one aspect, when the molded article is an intermediate molded article having a relatively high moisture content and a fiber content of about 20 to 50% by weight, preferably about 30 to 40% by weight, the surface of the molded article is coated with a barrier agent.

In one embodiment, this disclosure provides a cellulose-based product obtained according to any method disclosed herein, which is a three-dimensional molded product made of cellulose fibers, such as a molded food packaging product.

In one respect, there are no particular limitations on the three-dimensional shapes obtained by manufacturing molded articles.

In one respect, examples of the three-dimensional shape are bowls, cups, plates, forks, spoons, or knives.

In some embodiments, the blocking agent consists essentially of CNF and SGF admixtures.

In some embodiments, the weight ratio of CNF to SGF admixture in the blocking agent is from about 20:1 to about 1:5. In some embodiments, the weight ratio may be from about 5:1 to about 1:5.

In some embodiments, when the total weight of the blocking agent is considered to be 100% by weight, the blocking agent comprises about 4% by weight to about 96% by weight of CNF and about 4% by weight to about 96% by weight of SGF admixture. In some embodiments, the amount of CNF may be about 10% by weight to about 70% by weight. In some embodiments, the amount of SGF admixture may be about 30% by weight to about 90% by weight.

In some embodiments, the blocking agent further includes one or more alcohol-soluble glutenins.

In some embodiments, the one or more gliadin proteins are selected from wheat (wheat gliadin), barley (barley gliadin), rye (rye gliadin), corn (corn gliadin), sorghum (sorghum gliadin), and/or oats (oat gliadin).

In some embodiments, the cellulose-based material comprises cellulose fibers suitable for papermaking, and the aqueous mixture or dispersion is a papermaking ingredient or raw material.

In some embodiments, the molded article exhibits a water contact angle equal to or greater than 90°, equal to or greater than 100°, equal to or greater than 110°, or equal to or greater than 120°.

In some embodiments, the molded article exhibits a TAPPI T 559KIT test value of 3 to 12.

In some embodiments, the molded article exhibits reduced gas permeability (referred to as "gas barrier properties") (e.g., barrier to oxygen, nitrogen, and carbon dioxide). In some aspects, the gas barrier property is reduced oxygen permeability.

In some embodiments, the molded article exhibits a water contact angle of 90° or greater and/or a TAPPI T 559KIT test value of 3 to 12 in the absence of any second hydrophobic material.

In some embodiments, the barrier agent is in the form of an emulsion.

In some embodiments, the barrier agent is a stable aqueous composition.

In another embodiment, a method for manufacturing a cellulose-based product with barrier properties is provided, the method comprising: obtaining an ingredient comprising an aqueous mixture of cellulose fibers; adding an SGF blend to the ingredient; adding CNF to the ingredient; and adding a retention aid to the ingredient to help retain the SGF blend on the cellulose fibers.

In some embodiments, one or more charged polymers may be added to the wet end to help retain the SFAE on the cellulose-based material. The charged polymers may include one or more cationic polymers, anionic polymers, nonionic polymers, and/or zwitterionic polymers. In some embodiments, the charged polymers comprise a combination of a relatively low molecular weight cationic polymer and a relatively high molecular weight anionic polymer.

In some embodiments, the charged polymer is composed of one or more cationic polymers. The one or more cationic polymers may include polyacrylamide. The polyacrylamide may include polyDADMAC (polydiallyldimethylammonium chloride) or alum (aluminum sulfate).

In some implementations, one or more alcohol-soluble glutenins may be added to the wet end to help retain SGF blends, CNFs, and/or improved CNFs on the cellulose-based material.

Detailed Implementation

Before describing the compositions, methods, and methodologies of the present invention in more detail, it should be understood that this disclosure is not limited to the specific compositions, methods, and experimental conditions described, as such compositions, methods, and conditions can vary. It should also be understood that the terminology used herein is for the purpose of describing specific embodiments only and is not intended to limit the invention, as the scope of the invention is limited only by the appended claims.

As used in this specification and the appended claims, the singular forms “a,” “an,” and “the” include references to the plural, unless the context clearly specifies otherwise. Thus, for example, references to “a sugar fatty acid ester” include one or more sugar fatty acid esters and/or compositions of the type described herein, as will be apparent to those skilled in the art upon reading this disclosure, etc.

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure pertains. Any methods and materials similar to or equivalent to those described herein may be used in the practice or testing of this disclosure, as it should be understood that modifications and variations are contained within the spirit and scope of this disclosure.

This disclosure provides an improved cellulose nanofiber adhesive.

Cellulose nanofibers (also referred to herein as CNFs) and their production methods are well known in the art.

The CNF used in the embodiments of this disclosure is not particularly limited. The CNF is commercially available or can be manufactured by known methods, which typically involve subjecting a source of cellulose fibers (e.g., wood pulp) to mechanical shear forces.

There are no particular limitations on the performance of the CNF. The CNF may have a typical fibril width of about 5 to 20 nanometers and a length of several micrometers.

In some embodiments, the improved CNF can be obtained by contacting conventionally manufactured CNF with an SGF blend and binding the SGF blend to the CNF. In other embodiments, the improved CNF can be obtained by subjecting a source of cellulose fibers (e.g., wood pulp) to mechanical shear stress while the CNF is present in a mixture with an SGF blend.

As described above, the improved CNF offers several benefits compared to conventionally used CNF, such as maintaining or increasing the rate at which the fiber pad drains from the slurry and reducing CNF agglomeration.

This disclosure provides a method for imparting barrier properties to a cellulose-based material. The method includes contacting the cellulose-based material with a barrier agent for imparting barrier properties, and bonding the barrier agent to the surface of the cellulose-based material to obtain a bonded cellulose-based material with barrier properties, wherein the barrier properties are selected from one or more of water resistance, gas barrier properties, and grease resistance. The barrier agent may include the improved CNF, or the barrier agent may include an improved CNF and SGF blend.

The methods disclosed herein can provide a solvent-free, bio-based, high-temperature resistant barrier (or barrier coating) and/or molded fiber (e.g., molded) product having these properties for oils and greases (OGR), water and/or gases (e.g., oxygen, nitrogen and carbon dioxide).

Another aspect of this disclosure is that the barrier coating can be configured to provide improved water and grease (oil/grease) resistance without the use of PFAS. These barrier properties can be provided by SGF dopants (see, for example, '073 disclosure, '953 disclosure, '923 application, '499 application, '433 application and '097 application, all of which are incorporated herein by reference).

In some embodiments, the improved CNF can be used in the wet end of the papermaking process by directly adding it to the papermaking ingredients. Alternatively, in other embodiments, a combination of CNF and SGF admixtures can be directly added to the papermaking ingredients to obtain similar benefits.

One or more charged polymers, such as polydADMAC or polyacrylamide, may also be added to the formulation as retention aids to promote the absorption of SGF admixtures and/or CNFs on cellulose surfaces. In some aspects, the charged polymers can be used to control the electrostatic charge of formulations containing SGF admixtures.

In other embodiments, glucogluten can be used as a binder. This is illustrated, for example, in U.S. Provisional Application No. 63/044,820 (hereinafter referred to as the “'820 Application”), filed on June 26, 2020, the entire text of which is incorporated herein by reference.

Glycol-soluble gluten can be used not only as a binder for SGF incorporations and/or CNF, but also as a conventional pigment added to papermaking ingredients. Pigments are typically relatively small and charged on their surface (including their edges). Therefore, pigments are readily captured (and selectively retained) by the glycol-soluble gluten matrix.

In addition to being added directly to papermaking ingredients, the barrier agent can also be applied to cellulose-based materials or substrates (e.g., pre-formed paper products) by impregnation, spraying, coating, printing, extrusion coating, metering, or any combination of these methods. The barrier agent may contain a sufficient amount of improved CNF to impart the desired water resistance and/or OGR to the cellulose-based material.

Alternatively, the barrier agent may contain appropriate amounts of CNF and SGF blends to impart the desired water resistance and/or OGR to the cellulose-based material.

Alternatively, the barrier formulation may contain appropriate amounts of improved CNF and SGF blends to impart the desired water resistance and/or OGR to the cellulose-based material.

In this disclosure, the interaction between the SGF dopant and CNF can be achieved through ionic, hydrophobic, van der Waals, covalent bonding, or a combination thereof. As used herein, “bind,” including its grammatical variations, means to adhere or cause to adhere into a substantially single substance, and can refer to ionic, hydrophobic, van der Waals, or covalent bonding, or a combination thereof.

In this disclosure, the interaction between the SGF dopant and the cellulose-based material can be achieved through ionic, hydrophobic, van der Waals, covalent, or combinations thereof.

In this disclosure, the interaction between the improved CNF and the cellulose-based material can be achieved through ionic, hydrophobic, van der Waals, covalent bonding, or a combination thereof.

In some embodiments, the barrier agent may also contain one or more conventional adhesives used in papermaking, such as latex, PvOH, and starch.

As used herein, “cellulosic” refers to a natural, synthetic, or semi-synthetic material that can be molded or extruded into objects (e.g., bags, sheets) or films or filaments, which can be used to manufacture such objects, films, or filaments and are structurally and functionally similar to cellulose, such as coatings and adhesives (e.g., carboxymethyl cellulose). In another instance, cellulose—a complex carbohydrate ( _{C6H10O5 ) n} composed of glucose units, which is the main component forming the cell wall in most _plants —is cellulosic.

Examples of cellulose materials (or cellulose-based materials) used in this article may be cellulose fibers, microfibrillated cellulose (MFC), nanofibrillated cellulose (or CNF), or cellulose nanocrystals commonly used in the paper industry.

As used herein, “coating weight” is the weight of the material (wet or dry) applied to a substrate. It is expressed in pounds per specified order or grams per square meter.

As used in this article, “effect”, including its grammatical variations, refers to the specific properties that a particular material is given.

As used in this article, "hydrophobic" means a substance that does not attract water. Examples of hydrophobic substances include waxes, rosin, resins, sugar fatty acid esters, fatty acid salts, glycerides with long fatty acid chains; diglycerides and triglycerides, diene ketones, shellac, vinyl acetate, PLA, PEI, oils, fats, lipids, other water-repellent chemicals, or combinations thereof.

As used in this article, "hydrophobicity" refers to the property of being waterproof, easily repelling water, and not absorbing water.

As used in this article, "lipophilicity" or "lipotropy" refers to the property of resisting lipids, readily repelling them, and not absorbing lipids, oils, fats, etc. In related aspects, lipophilicity can be measured using the 3M KIT test, the TAPPI T559 Kit test, or the Cobb oil test.

As used herein, “cellulose-containing materials” or “cellulose-based materials” means compositions that are essentially composed of cellulose. Examples of such materials include, but are not limited to, paper, paperboard, pulp, cartons for food storage, parchment paper, cake boards, meat paper, release paper/liners for pressure-sensitive adhesives, bags for food storage, shopping bags, shipping bags, bacon boards, insulating materials, tea bags, containers for coffee or tea, compost bags, tableware, containers for hot or cold beverages, cups, lids, plates, bottles for storing carbonated liquids, gift cards, bottles for storing non-carbonated liquids, films for packaging food, waste disposal containers, food handling equipment, textile fibers (e.g., cotton or cotton blends), water storage and delivery equipment, alcoholic or non-alcoholic beverages, casings or screens of electronic products, internal or external components of furniture, curtains, and interior decoration.

As used herein, “fibers in solution” or “pulp” means fibrous materials of lignocellulose obtained by chemically or mechanically separating cellulose fibers from wood, fiber crops, or waste paper. In a related aspect, when cellulose fibers are processed by the methods disclosed herein, the cellulose fibers themselves contain bound SFAEs, glycerides, and/or FAS as separated entities, and the bound cellulose fibers have properties that are different from and unique to free fibers (e.g., materials bound with pulp- or cellulose fiber- or nanocellulose or microfibrillated cellulose-SFAE blends do not readily form hydrogen bonds between fibers as readily as unbound fibers).

As used in this article, “re-pulping” means making paper or paperboard products suitable for crushing into soft, shapeless material for reuse in the manufacture of paper or paperboard.

As used in this article, “adjustable,” including its grammatical variations, refers to a process of adjustment or adaptation to achieve a specific result.

As used herein, the “water contact angle” refers to the angle measured through a liquid where a liquid/vapor interface is in contact with a solid surface. It quantifies the wettability of a solid surface by a liquid. The contact angle reflects how strong the interaction between liquid and solid molecules is relative to their interactions with each other. On many highly hydrophilic surfaces, water droplets exhibit contact angles ranging from 0° to 30°. Generally, if the water contact angle is greater than 90°, the solid surface is considered hydrophobic. The water contact angle can be readily obtained using an optical surface tensiometer (see, for example, Dyne Testing, Staffordshire, United Kingdom).

As used in this article, “water vapor permeability” refers to breathability or the ability of a textile to transfer moisture. There are at least two different methods of measurement. One is the MVTR (moisture transmittance) test according to ISO 15496, which describes the water vapor transmission rate (WVP) of a fabric, and thus the extent to which sweat is transferred to the outside air. These measurements determine how many grams of moisture (water vapor) pass through one square meter of fabric in 24 hours (the higher the level, the higher the breathability).

In one aspect, water resistance can be determined using the TAPPI T 530 Hercules sizing test (i.e., a sizing test of paper by ink resistance). Measuring ink resistance using the Hercules method is best classified as a direct test of permeability. Other classification methods categorize it as a permeation rate test. There is no single best test for "measuring sizing." The choice of test depends on the end use and mill control requirements. This method is particularly suitable for mill control sizing testing to accurately detect changes in sizing levels. It provides the sensitivity of a floating ink test while offering repeatable results, shorter test times, and automated endpoint determination.

Sizing degree is an important characteristic of many types of paper, measured by its resistance to the penetration or absorption of aqueous liquids into the paper. Typical examples of such papers include paperboard for bags and containers, meat wrapping paper, writing paper, and certain printing grades.

If an acceptable correlation has been established between the test values and the end-use performance of the paper, this method can be used to monitor the production of paper or paperboard for a specific end-use. Due to the nature of the test and the penetrant, it may not be sufficiently correlated to be applicable to all end-use requirements. This method measures sizing degree by penetration rate. Other methods measure sizing degree by surface contact, surface penetration, or absorption. The sizing degree test is selected based on its ability to simulate the water contact or absorption patterns in the end-use. This method can also be used to optimize the cost of using sizing chemicals.

As used herein, “oxygen permeability” refers to the degree to which a polymer allows gases or fluids to pass through. The oxygen permeability (Dk) of a material is a function of diffusivity (D) (i.e., the rate at which oxygen molecules pass through the material) and solubility (k) (or the amount of oxygen molecules absorbed per volume of the material). Values of oxygen permeability (Dk) typically fall within the range of 10–150 x ^10⁻¹¹ ( ^cm² ml _O₂ ) / (s ml mmHg). A semi-logarithmic relationship has been established between the water content of hydrogels and oxygen permeability (in Barrer units). The International Organization for Standardization (ISO) uses the SI unit of pressure, hectopascal (hPa), to define permeability. Therefore, Dk = ^10⁻¹¹ ( ^cm² ml _O₂ ) / (s ml hPa). It can be converted to hPa units by multiplying the Barrer units by a constant of 0.75.

As used in this article, “biodegradable,” including its grammatical variations, means that it can be broken down into, in particular, harmless products through biological processes (e.g., through microorganisms).

As used herein, “recyclable” includes its grammatical variations, meaning materials (used and/or discarded items) that can be processed or manipulated to make them suitable for reuse.

As used herein, “Gurley second” or “Gurley number” is a unit describing the number of seconds required for 100 cubic centimeters (deciliters) of air to pass through a given 1.0 square inch of material at a pressure difference of 4.88 inches of water column (0.176 psi) (ISO 5636-5:2003) (porosity). Additionally, for stiffness, the “Gurley number” is a unit of force (1 milligram of force) required to deflect a given amount of material held vertically. This value can be measured on a Gurley Precision Instruments device (Troy, New York).

HLB—the hydrophilic-lipophilic balance of a surfactant—is a measure of its degree of hydrophilicity or lipophilicity, determined by calculating values in different regions of the molecule.

The Griffin method for nonionic surfactants, as described in a 1954 publication, is as follows:

HLB = 20 * M _h / M

Where M _{_h} is the molecular weight of the hydrophilic portion of the molecule, and M is the molecular weight of the entire molecule, with results ranging from 0 to 20. An HLB value of 0 corresponds to a completely lipophilic/hydrophobic molecule, while a value of 20 corresponds to a completely hydrophilic/lipophobic molecule.

HLB values can be used to predict the surfactant properties of molecules:

<10: Fat-soluble (water-insoluble)

>10: Water-soluble (lipid-insoluble)

1.5 to 3: Defoamer

3 to 6: W/O (water-in-oil) emulsifiers

7 to 9: Wetting and spreading agents

13 to 15: Detergent

12 to 16: O/W (oil-in-water) emulsifier

15 to 18: Solubilizers or water-soluble growth promoters.

In some embodiments, the HLB values of the SFAE/glyceride/FAS blends disclosed herein (or the entire formulation comprising said blend) may be in the lower range. In some embodiments, the HLB values of the SFAE/glyceride/FAS blends disclosed herein (or the entire formulation comprising said blend) may be in the middle to higher range.

As used herein, sucrose fatty acid esters (soybean oil fatty acid esters) derived from soybean oil are commercially available from Procter & Gamble Chemicals (Cincinnati, OH) under the trade name SEFOSE 1618U (see below for sucrose-polysaccharide soybean oil fatty acid esters) and contain one or more unsaturated fatty acids. This is an exemplary SFAE used in the methods and blocking formulations of this disclosure.

As used herein, “soybean oil fatty acid ester” means a mixture of salts of fatty acids derived from soybean oil. SFAEs used in the methods and blocking formulations of this disclosure may include or be derived from “soybean oil fatty acid esters”.

As used herein, "oilseed fatty acids" refers to fatty acids derived from plants, including but not limited to soybeans, peanuts, rapeseed, barley, canola, sesame seeds, cottonseed, palm kernels, grape seeds, olives, safflower, sunflower, dried coconut kernels, corn, coconut, flaxseed, hazelnuts, wheat, rice, potatoes, cassava, alfalfa, camellia seeds, mustard seeds, and combinations thereof. The fatty acid chain of the SFAE/glyceride/FAS blend can be oilseed fatty acids.

As used herein, “wet strength” refers to the degree to which the fibrous web (or other three-dimensional solid cellulose-based product) holding paper together resists tearing forces when the paper is wet. Wet strength can be measured using a Finch Wet Strength Device from Thwing-Albert Instrument Company (West Berlin, NJ). Wet strength is typically influenced by wet strength additives, such as basic conditioned cationic resins (kymene), cationic glyoxylate resins, polyamidoamine-epimercohydrin resins, and polyamine-epimercohydrin resins (including epoxy resins). In embodiments, the cellulose-based material coated with the barrier formulation disclosed herein achieves this wet strength in the absence of such additives.

As used in this article, “wet” means covered or saturated with water or another liquid.

The methods disclosed herein may include the additional step of exposing the contacted cellulose-based material to heat, radiation, a catalyst, or a combination thereof for a sufficient duration to bind SGF dopants, CNFs, and/or modified CNFs to the cellulose-based material. In a related aspect, such radiation may include, but is not limited to, UV, IR, visible light, or combinations thereof. In another related aspect, the reaction may be carried out at room temperature (i.e., 25°C) to about 150°C, about 50°C to about 100°C, or about 60°C to about 80°C.

As used herein, the term “natural wax” refers to a material with a relatively high molecular weight/high melting point. Specific examples of “natural wax” include, for example, biowaxes obtained from renewable resources (e.g., vegetable oils, fatty acids, and fatty esters) (see, for example, https://www.researchgate.net/publication/318385619_High_Quality_Biow axes_from_Fatty_Acids_and_Fatty_Esters_Catalyst_and_Reaction_Mech anism_for_Accompanying_Reactions; and https://www.researchgate.net/figure/a-Preparation-of-canola-PFFA-18-bio wax-b-Preparation-of-nanocellulose-from-canola_fig1_306527797).

As used herein, the term "cellulose crosslinker" refers to known cellulose crosslinkers, such as glyoxal and small reactive dialdehydes or acid anhydrides.

The term "glyceride" as used herein has its usual meaning and refers to acylglycerol, an ester formed from glycerol and fatty acids. Glycerol has three hydroxyl functional groups, which can be esterified with one, two, or three fatty acids to form monoglycerides, diglycerides, and triglycerides. The fatty acid chains of these structures can differ because they can contain different numbers of carbons, different degrees of unsaturation, and different olefin configurations and positions.

Glycerides can be obtained by esterifying essentially pure fatty acids using known esterification methods. Glycerides can also be extracted from vegetable oils and animal fats using known extraction methods.

As used herein, the term "fatty acid" has its usual meaning and refers to a carboxylic acid having an aliphatic chain, which may be saturated or unsaturated. The term "fatty acid" as used herein may also refer to a fatty acid group bound to a glycerol residue of a glycerol ester.

The fatty acid groups of the glycerides can be any known fatty acid. In preferred embodiments, the known fatty acids are present in food, are edible, and/or are FDA approved. In some embodiments, the fatty acids are obtained from oilseeds. In other embodiments, the fatty acids are obtained from other sources of natural edible fats and oils.

The fatty acids in glycerides can be independently selected from one or more saturated fatty acids, one or more monounsaturated fatty acids, and/or one or more polyunsaturated fatty acids. Independently, this means, for example, that triglycerides can contain three different fatty acid groups attached to a glycerol residue.

Exemplary saturated fatty acids used in the formulations/compositions of this disclosure may be selected from butyric acid, hexanoic acid, octanoic acid, decanoic acid, lauric acid, myristic acid, palmitic acid, stearic acid, arachidic acid, bezoaric acid, or ligustic acid.

The exemplary monounsaturated fatty acids used in the formulations/compositions disclosed herein may be selected from decenoic acid (dec-9-enoic acid), myristic acid ((Z)-dodec-9-enoic acid), myristone acid ((Z)-tetradec-9-enoic acid), palmitoleic acid ((Z)-hexadec-9-enoic acid), oleic acid ((Z)-octadec-9-enoic acid), transoleic acid ((E)-octadec-9-enoic acid), isoleic acid ((E)-octadec-11-enoic acid), codoleic acid ((Z)-eicosyl-9-enoic acid), erucic acid ((Z)-docosa-13-enoic acid), brassinolic acid ((E)-docosa-13-enoic acid), or nervonic acid ((Z)-docosa-15-enoic acid).

The exemplary polyunsaturated fatty acids used in the formulations/compositions disclosed herein may be selected from linoleic acid (LA) ((9Z,12Z)-octadecano-9,12-dienoic acid), alpha-linolenic acid (ALA) ((9Z,12Z,15Z)-octadecano-9,12,15-trienoic acid), gamma-linolenic acid (GLA) (6Z,9Z,12Z)-octadecano-6,9,12-trienoic acid), columbinic acid ((5E,9E,12E)-octadecano-5,9,12-trienoic acid), octadecanotic terephthalic acid ((6Z,9Z,12Z,15Z)-octadecano-6,9,12,15-tetraenoic acid), metaric acid ((5Z,8Z,11Z)-eicosano-5,8,11-trienoic acid), dihydroxy-gamma-linolenic acid, etc. -Linolenic acid (DGLA) ((8Z,11Z,14Z)-eicosano-8,11,14-trienoic acid), arachidonic acid ((5Z,8Z,11Z,14Z)-eicosano-5,8,11,14-tetraenoic acid), eicosapentaenoic acid (EPA) ((5Z,8Z,11Z,14Z,17Z)-eicosano-5,8,11,14,17-pentaenoic acid), docosapentaenoic acid (DPA) ((7Z,10Z,13Z,16Z,19Z)-docosapentaenoic acid 7,10,13,16,19-pentaenoic acid), docosahexaenoic acid (DHA) ((4Z,7Z,10Z,13Z,16Z,19Z)-docosapentaenoic acid 4,7,10,13,16,19-hexaenoic acid).

In some embodiments, the one or more glycerides may comprise a mixture of one or more monoglycerides, one or more diglycerides, and/or one or more triglycerides. In this respect, monoglycerides, diglycerides, and triglycerides may be mixed in any weight ratio. That is, any one of monoglycerides, diglycerides, or triglycerides may be the major glyceride component of the formulation (by weight) (i.e., greater than 50% by weight when the total weight of glycerides is considered 100% by weight). In other embodiments, the formulation does not include monoglycerides; does not include diglycerides; or does not include triglycerides.

The fatty acid alkyl groups of the one or more glycerides may be different. For example, the one or more glycerides may contain fatty acid groups with different carbon numbers, different degrees of unsaturation, and/or different olefin configurations and positions. Various glycerides may include tripalmitate glycerides and/or tristearate glycerides.

In some embodiments, the glyceride may comprise one or more water-insoluble glycerides (e.g., as described above, triglycerides are generally strongly nonpolar and hydrophobic) and a combination of one or more water-soluble glycerides (in any weight ratio of 0.1:99.9 to 99.9:0.1); or only insoluble glycerides; or only insoluble glycerides. The solubility of the glyceride may be determined, for example, by its HLB value.

Those skilled in the art will understand that the HLB value of one or more of the glycerides described above can be selected by changing one or more parameters of the glycerides. In this regard, when using multiple glycerides, each glyceride can be selected to have similar or different HLB values (e.g., a combination of lower and higher ranges).

As used herein, the term "fatty acid salt" (or "FAS") has its usual meaning and refers to a salt of any one or more fatty acids disclosed herein. Exemplary cations of fatty acid salts include, but are not limited to, calcium, potassium, and sodium salts. Fatty acid salts can be synthesized by known methods or extracted from vegetable oils or animal fats by known methods. An exemplary method involves adding sodium hydroxide to fatty acids found in animal fats or vegetable oils (e.g., from oil-bearing seeds). For example, sodium palmitate can be obtained from palm oil.

The one or more fatty acid salts may include one or more calcium, potassium, or sodium salts. The calcium, potassium, or sodium salts of the fatty acids may be obtained from naturally occurring sources (e.g., oilseeds). The one or more fatty acid salts may include one or more selected from sodium oleate, sodium stearate, sodium palmitate, calcium oleate, calcium stearate, or calcium palmitate.

In some embodiments, the SGF blend may contain only one or more glycerides, only one or more fatty acid salts, or both one or more glycerides and one or more fatty acid salts. When the SGF blend contains one or more glycerides and one or more fatty acid salts, the weight ratio of the glycerides to the fatty acid salts may be from about 0.1:99.9 to about 99:0.1, from about 10:90 to about 90:10, from about 20:80 to about 80:20, from about 35:65 to about 65:35, from about 40:60 to about 60:40, from about 45:55 to about 55:45, or about 50:50.

The weight ratio of SFAE in the SGF dopant can be 0:100 to 100:0 or any weight ratio therebetween (e.g., 1:99; 5:95; 10:90; 20:80; 30:70; 40:60; 50:50; 60:50; 70:30; 80:20; 90:10; 95:5; 99:1).

The weight ratio of glycerides in SGF blends can be 0:100 to 100:0 or any weight ratio therebetween (e.g., 1:99; 5:95; 10:90; 20:80; 30:70; 40:60; 50:50; 60:50; 70:30; 80:20; 90:10; 95:5; 99:1).

The weight ratio of fatty acid salts in SGF blends can be from 0:100 to 100:0 or any weight ratio therebetween (e.g., 1:99; 5:95; 10:90; 20:80; 30:70; 40:60; 50:50; 60:50; 70:30; 80:20; 90:10; 95:5; 99:1).

The weight ratio of natural waxes in SGF blends can be 0:100 to 100:0 or any weight ratio therebetween (e.g., 1:99; 5:95; 10:90; 20:80; 30:70; 40:60; 50:50; 60:50; 70:30; 80:20; 90:10; 95:5; 99:1).

The weight ratio of cellulose crosslinking agents in SGF blends can be from 0:100 to 100:0 or any weight ratio therebetween (e.g., 1:99; 5:95; 10:90; 20:80; 30:70; 40:60; 50:50; 60:50; 70:30; 80:20; 90:10; 95:5; 99:1).

At sufficient concentrations, and based on the choice of admixtures, the combination of SGF admixtures alone is sufficient to make the contacted substrate hydrophobic: that is, to achieve hydrophobicity without the addition of waxes, rosin, resins, diene ketones, shellac, vinyl acetate, PLA, PEI, oils, other waterproofing chemicals or combinations thereof (i.e., a second hydrophobic agent), including achieving other properties of cellulose-based materials, such as reinforcement, hardening and swelling, solely through the combination of glycerol esters/fatty acid salts.

CNF alone has also been shown to increase the hydrophobicity of the substrates it comes into contact with.

Saturated SFAEs, glycerides, and fatty acid salts are typically solids at the nominal processing temperature, while unsaturated SFAEs, glycerides, and fatty acid salts are typically liquids. This allows saturated glycerides and fatty acid salts to form a homogeneous and stable dispersion in waterborne coatings without significant interactions or incompatibility with other typically hydrophilic coating components. Furthermore, this dispersion allows for the production of high concentrations of saturated glycerides and fatty acid salts without adversely affecting coating rheology, uniform coating application, or coating performance properties. The coating surface becomes hydrophobic as the particles of saturated glycerides and fatty acid salts melt and spread during coating heating, drying, and consolidation. The natural waxes disclosed herein are also solids at the nominal processing temperature.

Sugar fatty acid esters of all sugars (including monosaccharides, disaccharides, and trisaccharides) are applicable to all aspects of this disclosure. The sugar fatty acid esters can be monoesters, diesters, triesters, tetraesters, pentaseers, hexaesters, heptaesters, or octaesters, or combinations thereof, including the fatty acid moiety, which can be saturated, unsaturated, or a combination thereof.

SFAEs may consist of or be primarily composed of sucrose esters of fatty acids.

Many methods are known and can be used to manufacture or provide the SFAEs of this disclosure, and all of these methods are considered to be applicable within the broad scope of this disclosure. For example, in some embodiments, it is preferable to synthesize fatty acid esters by partially esterifying sugars derived from oilseeds, including but not limited to soybean oil, sunflower oil, olive oil, rapeseed oil, peanut oil, and mixtures thereof.

SFAEs may comprise a sugar moiety, including but not limited to a sucrose moiety, which has been substituted with an ester moiety at one or more of its hydroxyl hydrogens. In related respects, disaccharide esters used in this disclosure may have the structure of Formula I disclosed in '073, the entire contents of which are incorporated herein by reference.

Disaccharides suitable for SFAE may also include xylose, glucose, raffinose, maltodextrose, galactose, combinations of glucose, combinations of fructose, maltose, lactose, combinations of mannose, combinations of erythrose, isomaltose, isomaltulose, trehalose, trehalulose, cellobiose, laminabiose, chitobiose, and combinations thereof.

In other embodiments, starch fatty acid esters may be used, wherein the starch may be derived from any suitable source, such as dent corn starch, glutinous corn starch, potato starch, wheat starch, rice starch, sago starch, tapioca starch, sorghum starch, sweet potato starch, and mixtures thereof.

For use in the compositions disclosed herein, the SFAE compound may have a high degree of substitution. In some embodiments, the sugar fatty acid ester is a sucrose-based soybean oil fatty acid ester.

Sucrose-rich soybean oil fatty acid esters (1618U)

SFAEs can be manufactured in the manner disclosed in application '073. For example, sugar fatty acid esters can be manufactured by esterification of substantially pure fatty acids using known esterification methods. They can also be manufactured by transesterification of fatty acid esters in the form of sugars and fatty acid glycerides derived from, for example, natural sources, such as those found in oils extracted from oil-bearing seeds (e.g., soybean oil). Transesterification reactions using fatty acid glycerides to provide sucrose fatty acid esters are described, for example, in U.S. Patent Nos. 3,963,699; 4,517,360; 4,518,772; 4,611,055; 5,767,257; 6,504,003; 6,121,440; and 6,995,232, and International Publication WO1992004361, all of which are incorporated herein by reference in their entirety.

Cellulose-based products produced by the methods disclosed herein can be configured to exhibit greater hydrophobicity (or water resistance) compared to the same untreated cellulose-containing material. In a related aspect, treated cellulose-containing materials exhibit greater oleophobicity (or OGR) compared to the same untreated cellulose-containing material. In another related aspect, the treated cellulose-containing material can be biodegradable, compostable, and/or recyclable. In one aspect, the treated cellulose-containing material is both hydrophobic (water-resistant) and oleophobic (lipid-resistant) (OGR).

Compared to the same untreated material, the cellulose-based products of this disclosure can have improved mechanical properties. For example, paper bags treated by the methods disclosed herein exhibit increased burst strength, Gurley number, tensile strength, and/or maximum load energy. In one aspect, the burst strength increases by about 0.5 to 1.0 times, about 1.0 to 1.1 times, about 1.1 to 1.3 times, and about 1.3 to 1.5 times. In another aspect, the Gurley number increases by about 3 to 4 times, about 4 to 5 times, about 5 to 6 times, and about 6 to 7 times. In yet another aspect, the tensile strain increases by about 0.5 to 1.0 times, about 1.0 to 1.1 times, about 1.1 to 1.2 times, and about 1.2 to 1.3 times. And in yet another aspect, the maximum load energy increases by about 1.0 to 1.1 times, about 1.1 to 1.2 times, about 1.2 to 1.3 times, and about 1.3 to 1.4 times.

The cellulose-containing material is a base paper comprising microfibrillated cellulose (MFC) or cellulose nanofibers (CNF), as described, for example, in U.S. Patent Application Publication No. 2015/0167243 (incorporated herein by reference in its entirety), wherein the MFC or CNF is added and/or added as a coating or second layer to previously formed layers during the forming and papermaking processes to reduce the porosity of the base paper. In embodiments, the resulting contacted base paper is tunably resistant to water and lipids. In related aspects, the resulting base paper may exhibit a Gurley value of at least about 10-15, or at least about 100, at least about 200 to about 350 (i.e., Gurley air resistance (s/100cc, 20oz.cyl.)). In one aspect, the barrier coating disclosed herein may be a single or multiple layers of laminated material, or the barrier coating disclosed herein may provide one or more layers as a laminated material, or the barrier coating disclosed herein may reduce the amount of one or more layers of coating to achieve the same performance effect (e.g., water resistance, grease resistance, etc.). In a related aspect, the laminated material may contain a biodegradable and/or compostable heat sealant or adhesive.

In the implementation, the SGF blend may be combined (alone or in combination) with one or more coating components for internal and surface sizing, including but not limited to pigments (e.g., clay, calcium carbonate, titanium dioxide, plastic pigments), binders (e.g., starch, soy protein, polymer emulsions, PvOH, casein) and additives (e.g., glyoxal, glyoxylate resin, zirconium salts, polyethylene emulsions, carboxymethyl cellulose, acrylic polymers, alginates, polyacrylate adhesives, polyacrylates, microbial agents, oil-based defoamers, silicone-based defoamers, stilbene, direct dyes, and acid dyes). In related aspects, these components can provide one or more properties, including but not limited to: establishing a fine porous structure; providing a light-scattering surface; improving ink acceptability; improving gloss; binding pigment particles; bonding coatings to paper; strengthening the substrate; filling pores in the pigment structure; reducing water sensitivity; preventing wet scratching in offset printing; preventing doctor blade scratching; improving gloss in supercalendering; reducing dust; adjusting coating viscosity; providing water retention; dispersing pigments; maintaining coating dispersion; preventing coating/coating color deterioration; controlling bubbling; reducing entrained air and coating porosity; increasing whiteness and brightness; and controlling color and hue. It will be apparent to those skilled in the art that the combination can be modified to suit the desired properties of the final product.

In wet-end applications, the SGF blend may be present in the aqueous mixture or dispersion at a concentration of at least 0.025% (wt/wt) of the total cellulose fibers present in the dispersion. In related aspects, the SGF blend may be present at a concentration of about 0.05% (wt/wt) to about 0.1% (wt/wt), about 0.1% (wt/wt) to about 0.5% (wt/wt), about 0.5% (wt/wt) to about 1.0% (wt/wt), about 1.0% (wt/wt) to about 2.0% (wt/wt), about 2.0% (wt/wt) to about 3.0% (wt/wt), about 3.0% (wt/wt) to about 4.0% (wt/wt), about 4.0% (wt/wt) to about 5.0% (wt/wt), about 5.0% (wt/wt) to about 10% (wt/wt), or about 10% (wt/wt) to about 50% (wt/wt) of the total fibers present.

In wet-end applications, CNF may be present in the aqueous mixture or dispersion at a concentration of at least 0.025% (wt/wt) of the total cellulose fibers present in the dispersion. Relatedly, CNF may be present at concentrations of about 0.05% (wt/wt) to about 0.1% (wt/wt), about 0.1% (wt/wt) to about 0.5% (wt/wt), about 0.5% (wt/wt) to about 1.0% (wt/wt), about 1.0% (wt/wt) to about 2.0% (wt/wt), about 2.0% (wt/wt) to about 3.0% (wt/wt), about 3.0% (wt/wt) to about 4.0% (wt/wt), about 4.0% (wt/wt) to about 5.0% (wt/wt) of the total fibers present. It is present in about 5.0% (wt/wt) to about 10% (wt/wt), about 10% (wt/wt) to about 20% (wt/wt), about 20% (wt/wt) to about 30% (wt/wt), about 30% (wt/wt) to about 40% (wt/wt), about 40% (wt/wt) to about 50% (wt/wt), about 60% (wt/wt) to about 70% (wt/wt), about 70% (wt/wt) to about 80% (wt/wt), or about 80% (wt/wt) to about 90% (wt/wt).

In wet-end applications, the modified CNF may be present in the aqueous mixture or dispersion at a concentration of at least 0.025% (wt/wt) of the total cellulose fibers present in the dispersion. Relatedly, the modified CNF may be present at concentrations of approximately 0.05% (wt/wt) to approximately 0.1% (wt/wt), approximately 0.1% (wt/wt) to approximately 0.5% (wt/wt), approximately 0.5% (wt/wt) to approximately 1.0% (wt/wt), approximately 1.0% (wt/wt) to approximately 2.0% (wt/wt), approximately 2.0% (wt/wt) to approximately 3.0% (wt/wt), approximately 3.0% (wt/wt) to approximately 4.0% (wt/wt), and approximately 4.0% (wt/wt) to approximately 5.0% (wt/wt) of the total fibers present. It is present in about 5.0% (wt/wt) to about 10% (wt/wt), about 10% (wt/wt) to about 20% (wt/wt), about 20% (wt/wt) to about 30% (wt/wt), about 30% (wt/wt) to about 40% (wt/wt), about 40% (wt/wt) to about 50% (wt/wt), about 60% (wt/wt) to about 70% (wt/wt), about 70% (wt/wt) to about 80% (wt/wt), or about 80% (wt/wt) to about 90% (wt/wt).

As used herein, “coating weight” is the weight of the material (wet or dry) applied to a substrate. It is expressed in pounds per specified order or grams per square meter.

In coating application, the improved CNF may be present on the surface of the substrate at a coating weight of at least about 0.05 g/ ^m² . In related aspects, the SGF admixture may be present on the surface of the cellulose-based material at ^a coating ^weight of about 0.05 g/ ^m² to about 1.0 g/ ^m² , about 1.0 g/ ^m² to about 2.0 g/ ^m² , about 2 g/ ^m² to about 3 g/ ^m² , 3 g/ ^m² to about 4 g/ ^m² , about 4 g/ ^m² to about 5 g/m², about 5 g/ ^m² to about 10 g/m², or about 10 g/ ^m² to about 20 g/ ^m² .

In coating application, the SGF admixture may be present on the surface of the substrate at a coating weight of at least about 0.05 g/ ^m² . In related aspects, the SGF admixture may be present on the surface of the cellulose-based material at ^a coating ^weight of about 0.05 g/ ^m² to about 1.0 g/ ^m² , about 1.0 g/ ^m² to about 2.0 g/ ^m² , about 2 g/ ^m² to about 3 g/ ^m² , 3 g/ ^m² to about 4 g/ ^m² , about 4 g/ ^m² to about 5 g/m², about 5 g/ ^m² to about 10 g/m², or about 10 g/ ^m² to about 20 g/ ^m² .

In coating application, CNF may be present on the surface of the cellulose-based material (or substrate) at a coating weight of at least about 0.05 g/ ^m² (gsm). In related aspects, CNF may be present on the surface of ^the cellulose-based material at a coating weight of about 0.05 g/ ^m² to about 1.0 g/ ^m² , about 1.0 g/ ^m² to about ^2.0 g/ ^m² , about ² g/m² to about 3 g/ ^m² , 3 g/ ^m² to about 4 g/ ^m² , about 4 g/ ^m² to about 5 g/m², about 5 g/ ^m² to about ¹⁰ g/ ^{m², about 10 g/m²} to about 20 g/m², or about 20 g/ ^m² to about 30 g/ ^m² .

In the absence of any second hydrophobic material, hydrophobic barrier properties can be imparted to the substrate by SGF dopants and/or improved CNF.

The barrier formulation may include one or more emulsifiers or emulsifying agents at concentrations sufficient to form an emulsion of SGF inclusions and water and/or an emulsion of improved CNF and water. Suitable emulsifiers or emulsifying agents include buffers, polyvinyl alcohol (PvOH), carboxymethyl cellulose (CMC), milk proteins, gelatin, starch, acetylated polysaccharides, alginate, carrageenan, chitosan, inulin, long-chain fatty acids, waxes, agar, alginate, glycerol, gums, lecithin, poloxamer, monoglycerides, diglycerides, monosodium phosphate, monostearate, propylene glycol, detergents, cetyl alcohol, glycerides, (saturated) ((poly)unsaturated) fatty acid methyl esters, and combinations thereof.

The methods disclosed herein may include steps of pre-determining the content of SGF admixtures and/or the components of the SGF admixtures to be included in the improved CNF. In some aspects, this pre-determining step may be performed prior to the manufacture of the improved CNF. Pre-determining steps can be performed to achieve desired effects. When the improved CNF is used in barrier formulations and/or added to papermaking feedstocks in the wet end, pre-determining steps can be performed to achieve desired levels of water resistance and/or desired levels of oil and grease resistance. In some aspects, pre-determining can be performed to increase the dewatering rate of the feedstock or cellulose pulp. Increasing the dewatering rate improves, for example, the rate of production of cellulose-based articles. As mentioned above, dewatering pulp containing CNF is one of the biggest problems involving the use of CNF. The increased dewatering rate is applicable, for example, to the manufacture of improved CNF binders and the use of the improved CNF binder in barrier formulations. Dewatering is well known in the papermaking industry and is also explained in Smook, the full text of which is incorporated herein by reference elsewhere in this disclosure.

The methods disclosed herein may include steps of pre-determining the content of SGF admixtures and/or pre-determining the components of the SGF admixtures to be included in the barrier formulation. In some aspects, this pre-determining step may be performed before manufacturing the barrier formulation or before the cellulose-based material is contacted with the formulation. The pre-determining steps can be performed to achieve a desired effect. The pre-determining steps can be performed to achieve a desired level of water resistance and/or a desired level of oil and grease resistance.

As described above, the barrier formulation may include one or more pigments commonly used in the paper industry. The one or more pigments may be present in the formulation at a concentration of about 0.1 wt% to about 90 wt%, based on the total weight of the formulation. In other aspects, the pigment concentration may be from about 1 wt% to 10 wt%, about 11 wt% to 20 wt%, about 21 wt% to 30 wt%, about 31 wt% to 40 wt%, about 41 wt% to 50 wt%, 51 wt% to 60 wt%, 61 wt% to 70 wt%, 71 wt% to 80 wt%, 81 wt% to 90 wt%, or any other range between 0.1 wt% and 90 wt%. The use of pigments is well known in the paper industry, and pigment concentrations can be selected to alter the properties of the final product. Example pigments include clay, calcium carbonate, titanium dioxide, kaolin, talc, plastic pigments, silica, silicates, metal oxides, alumina, aluminates, and diatomaceous earth.

As described above, the barrier agent may include one or more charged polymers to help retain improved CNF and/or SGF incorporations on a cellulose-based substrate. The one or more charged polymers may include one or more cationic polymers, anionic polymers, nonionic polymers, and/or zwitterionic polymers. The charged polymers may include a combination of relatively low molecular weight cationic polymers and relatively high molecular weight anionic polymers.

The charged polymer may be composed of one or more cationic polymers. The one or more cationic polymers may include polyacrylamide. The polyacrylamide may include polyDADMAC (polydiallyldimethylammonium chloride).

The cationic polymer may have a weight-average molecular weight of 500,000 to 10,000,000. In some aspects, the weight-average MW is 500,000 to 1,000,000, 1,000,001 to 2,000,000, 2,000,001 to 3,000,000, 3,000,001 to 4,000,000, 4,000,001 to 5,000,000, 5,000,001 to 6,000,000, 6,000,001 to 7,000,000, 7,000,001 to 8,000,000, 8,000,001 to 9,000,000, or 9,000,001 to 10,000. In some aspects, combinations of charged polymers having any of the above-mentioned MW ranges are used, employing mixtures of charged polymers to achieve a "bimodal" weight-average MW (e.g., a first charged polymer with a weight-average MW less than 1,000,000 is used in combination with a second charged polymer with a weight-average MW greater than 2,000,000; wherein the weight ratio of the first charged polymer to the second charged polymer is 10:90 to 90:10). In some embodiments, when the total weight of the formulation is considered 100%, the concentration of the cationic polymer in the formulation is about 0.01 wt% to about 5 wt%, about 0.01 wt% to about 3 wt%, 0.05 wt% to about 0.1 wt%, or about 0.1 wt% to about 1 wt%, or about 1 wt% to about 3 wt%. In some aspects, the weight ratio of the cationic polymer to the modified CNF in the formulation is about 0.1:99.9 to about 20:80, 0.5:99.5 to about 15:85, about 1:99 to about 10:90, or about 2.5:97.5 to about 7.5:92.5. In some aspects, the weight ratio of the cationic polymer to the SGF dopant in the formulation is about 0.1:99.9 to about 20:80, 0.5:99.5 to about 15:85, about 1:99 to about 10:90, or about 2.5:97.5 to about 7.5:92.5.

In some respects, as described above, alcohol-soluble gluten can be used as a retention aid in blocking formulations that include improved CNF and/or SGF blends but do not include charged polymers.

The barrier formulation may also include one or more conventional papermaking adhesives. Example adhesives include CNF, the improved CNF of this disclosure, starch, polymers, polymer emulsions, PvOH, alcohol-soluble gluten, or combinations thereof. In some aspects, the formulation may not contain any adhesives other than the improved CNF.

The barrier agent may be provided in the form of an emulsion. The emulsion may be used as a barrier agent in the methods of this disclosure. In some aspects, the emulsion may be free of any emulsifiers other than the SGF admixture. Alternatively, the emulsion may include one or more emulsifiers from about 0.01% to about 80% by weight. The emulsion may also include materials for stabilizing the emulsion over a period of time (e.g., weeks, months, etc.), such as nano- or microfibrillated cellulose, gums, or thickeners. A list of exemplary emulsifiers is provided above.

Cellulose-based materials or substrates can be dried (e.g., at about 80-150°C) prior to application, and can be treated with a modified formulation by, for example, impregnation, exposing the surface to the composition for less than 1 second. The substrate can be heated to dry the surface, and then the modified material can be used. In one aspect, the substrate can be treated by any suitable coating/sizing method commonly used in paper mills, according to the methods disclosed herein (see, for example, Smook, G., Surface Treatments in Handbook for Pulp & Paper Technologists, (2016), 4th edition, Chapter 18, pp. 293-309, Tappi Press, Peachtree Corners, GAUSA, the entire text of which is incorporated herein by reference).

No special preparation of the cellulose-based material is required when implementing this disclosure, although for some applications the material may be dried prior to treatment. In embodiments, the disclosed methods can be used on any cellulose-based surface, including but not limited to films, rigid containers, fibers, pulp, fabrics, etc. In one aspect, the barrier agent can be applied by: conventional sizing machines (vertical, inclined, horizontal), roller sizing machines, metering sizing machines, calendering, tube sizing, on-machine, off-machine, single-sided coating machines, double-sided coating machines, short-dwell, simultaneous double-sided coating machines, doctor blade or rod coating machines, gravure coating machines, gravure printing, flexographic printing, inkjet printing, laser printing, water tanks on calenders, and combinations thereof.

Depending on the source, the cellulose processed in the method described herein can be paper, paperboard, pulp, cork fiber, hardwood fiber, or a combination thereof, nanocellulose, cellulose nanofibers, whiskers or microfibers, microfibrillated cotton or cotton blends, cellulose nanocrystals, or nanofibrillated cellulose.

Additionally, modified fiber and cellulose-based materials, as disclosed herein, can be re-pulped. Furthermore, for example, water cannot be easily "pushed" over a low surface energy barrier to enter the sheet.

In some embodiments, the amount of the barrier agent applied is sufficient to completely cover at least one surface of the substrate, such as at least one surface of a cellulose-containing material. For example, in some embodiments, the barrier agent may be applied to the entire outer surface of a container, the entire inner surface of a container, or both inner and outer surfaces, or one or both sides of the base paper. In other embodiments, the entire upper surface of the membrane may be covered by the barrier agent, or the entire lower surface of the membrane may be covered by the barrier agent, or both upper and lower surfaces may be covered. In some embodiments, the inner cavity of the device/instrument may be covered by the barrier agent, or the outer surface of the device/instrument may be covered by the barrier agent, or both the inner cavity and the outer surface may be covered.

In an embodiment, the amount of the barrier agent applied is sufficient to partially cover at least one surface of the cellulose-based material. For example, only those surfaces exposed to the ambient atmosphere are covered by the barrier agent, or only those surfaces not exposed to the ambient atmosphere are covered by the barrier agent (e.g., masking). It will be apparent to those skilled in the art that the amount of the barrier agent applied may depend on the intended use of the material to be covered. In one aspect, one surface may be coated with the barrier agent, while the opposite surface may be coated with, but is not limited to, the following agents: proteins, wheat gluten, gelatin, alcohol-soluble gluten, soy protein isolate, starch, modified starch, acetylated polysaccharides, alginate, carrageenan, chitosan, inulin, long-chain fatty acids, waxes, and combinations thereof. In a related aspect, the barrier agent may be incorporated into the ingredients, and an additional barrier agent coating (having the same or different composition as the agent added to the wet end) may be provided to the material obtained on the web.

In carrying out these methods, any suitable coating method can be used to deliver any variety of barrier agents. In embodiments, the coating method includes dipping, spraying, smearing, printing, and any combination of these methods, alone or in conjunction with other coating methods suitable for carrying out the disclosed methods.

As the barrier properties of materials are improved, the permeability of surfaces to various gases, such as water vapor and gases (e.g., oxygen, nitrogen, and carbon dioxide), can also be altered by barrier agents. The standard unit for measuring permeability is the barrer, and protocols for measuring these parameters are also available in the public domain (ASTM std F2476-05 for water vapor, ASTM std F2622-8 for oxygen, and for general gases - https://www.ametekmocon.com/products/searchbybrand/mocon. For over 50 years, the MOCON Permeation Testing Analyzer has been recognized as an industry-leading solution and is the basis for many global permeation testing standards such as ASTM D3985 and ASTM F1249. MOCON's extensive product line represents decades of technological leadership and continuous innovation in partnership with our customers, distributors, and institutions. Our MOCON permeation analyzers offer a wide range of testing capabilities for the most diverse products and materials.” In some cases, permeability to vapors and gases can be further reduced by incorporating one or more alcohol-soluble glutenins into the barrier formulation.

In the implementation scheme, the materials treated according to the disclosed method exhibit complete biodegradability, as measured by degradation in an environment under microbial invasion.

There are several methods that can be used to define and test biodegradability, including the shake flask test (ASTM E1279-89(2008)) and the Zahn-Wellens test (OECD TG 302B).

There are many methods that can be used to define and test compostability, including but not limited to ASTM D6400.

The TAPPI T 559KIT test values of the barrier coating products disclosed herein can be approximately 3 to approximately 12, greater than 4, greater than 5, greater than 6, greater than 7, greater than 8, greater than 9, greater than 10, greater than 11, etc.

The HST value of the barrier coating product disclosed herein can be at least about 65 seconds, at least about 120 seconds, at least about 240 seconds, at least about 480 seconds, etc.

The surface of the barrier coating product disclosed herein can exhibit a water contact angle of about 60° to 120°, at least about 90°, at least about 100°, at least about 110°, at least about 120°, etc.

In some embodiments, the barrier formulations of this disclosure form stable aqueous compositions, the term "stable aqueous composition" being defined as an aqueous composition that, when contained in a closed container and stored in a temperature range of about 0°C to about 60°C, substantially resists viscosity changes, coagulation, and sedimentation for at least 8 hours. Some embodiments of the barrier formulations are stable for at least 24 hours and generally stable for at least 6 months.

In some embodiments, the barrier coating product obtained by the methods of this disclosure does not include PFAS. In some embodiments, the barrier coating product of this disclosure does not include PFAS in the barrier coating.

In some embodiments, the barrier coating product obtained by the method of this disclosure is folded into a three-dimensional shape and contained within a sealed package. In these embodiments, the barrier layer may be an exposed layer (or outer layer) inside the package. The package material may be any conventional material used for storing, transporting, or selling food or beverage products. In these embodiments, the sealed package may also contain a food or beverage product. In these embodiments, the food or beverage product may come into contact with the barrier paper layer. The seal of the sealed package may be an airtight seal.

In some implementations, the barrier coating products obtained by the methods of this disclosure are compatible with conventional paper recycling programs: that is, they do not adversely affect recycling operations as they do with polyethylene, polylactic acid, or waxed paper.

In some embodiments, the barrier coating product obtained by the methods of this disclosure is bio-based. As used herein, "bio-based" means a material intentionally made from substances derived from living (or formerly living) organisms. In related aspects, materials containing at least about 50% of such substances are considered bio-based. In some aspects, the barrier coating product obtained by the methods of this disclosure can be entirely bio-based. In some aspects, the barrier formulations of this disclosure can be entirely bio-based.

In some embodiments, the barrier coating product obtained by the methods of this disclosure is recyclable. As used herein, “recyclable” includes its grammatical variations, meaning a material (used and/or discarded articles) that can be processed or handled to make it suitable for reuse.

In some embodiments, the barrier coating products of this disclosure are biodegradable. As used herein, “biodegradable” includes its grammatical variations and means capable of being broken down into particularly harmless products by biological (e.g., by microbial) action.

Example

In the following, although embodiments of the present disclosure are described in more detail by way of examples, the present disclosure is not limited thereto.

Example 1

Example 1 is a laboratory study on the use of CNF in a molded pulp product with barrier properties.

The equipment used in Example 1 is as follows:

Buchner funnel - large (believed to be approximately 8 inches in diameter)

Vacuum bottle

Laboratory vacuum pump

spray bottle

Stopwatch

The materials that can be used in Example 1 are as follows:

Bleached kraft pulp (50% SWK, 50% HWK) is pulped at 1% solids.

CNF slurry - 0.5% solids

CNF slurry, with the addition of 10% SE-15* and 0.5% solids.

SE-9**/SE 30*** Emulsion, 1% Solids

C-PAM (cationic polyacrylamide), 0.1% solids

Cationic coagulant, 0.1% solids

Pigment, from IMERYS 1% solid Capim DG clay slurry.

*SE-15 is sourced from HANGZHOU UNION BIOTECHNOLOGY CO.,LTD. SE-15 is marketed as a sucrose fatty acid ester. Analysis of SE-15 revealed that it contains approximately 15 to 30% by weight of sucrose fatty acid esters, approximately 40 to 60% by weight of glycerides, and the remainder of fatty acid salts and trace components.

**SE-9 is sourced from ZHEJIANG SYNOSE TECH. SE-9 is marketed as a sucrose fatty acid ester. Analysis of SE-9 revealed that its composition is similar to SE-15, except that it has a higher glyceride content and approximately 10 to 20% less sucrose ester.

***SE-30 is sourced from EAST CHEMSOURCES LIMITED. SE-30 is marketed as a sucrose fatty acid ester. Analysis of SE-30 reveals that it contains over 80% sucrose esters with various substitutions. The remainder of the product is a glyceride with a relatively low (less than 5% by weight) salt content.

The test procedure for Example 1 is as follows:

Blank or contrast

(1) Add sufficient bleached kraft pulp to the Buchner funnel to produce a fiber mat with a basis weight of 150 gsm. Note the amount of material to be prepared for future operation.

(2) Once the slurry is added to the Buchner funnel, start the vacuum pump.

(3) Pay attention to the time when the ingredients are drained to the “wet line”, which is the point in time when the surface of the fiber pulp changes from a glossy or “wet” appearance to a dull, textured surface during the draining process.

(4) Continue to evacuate the wet sample for 10 seconds.

(5) Remove the wet pad from the Buchner funnel and place it between two sheets of absorbent paper. Roll the standard hand-held paper roller twice on the absorbent paper to compress the test sample.

(6) Take out the pressed sample and place it in a 100°C oven until dry.

Internal treatment (wet end application)

(1) Add one or more additives to equal portions of the slurry (volume determined during the manufacture of the control sample) and mix. See Table 1 below.

(2) Add a sufficient amount of mixed slurry to the Buchner funnel to produce a fiber mat with a basis weight of 150 gsm.

(3) Once the slurry is added to the Buchner funnel, start the vacuum pump.

(4) Pay attention to the time it takes to drain the ingredients until they are "wet".

(5) Continue to evacuate the wet sample for 10 seconds.

(6) Remove the wet pad from the Buchner funnel and place it between two sheets of absorbent paper. Roll the standard hand-held paper roller twice on the absorbent paper to compress the test sample.

(7) Take out the pressed sample and place it in a 100°C oven until dry.

Spray treatment (coating shaped products)

(1) Add sufficient bleached kraft pulp to the Buchner funnel to produce a fiber mat with a basis weight of 150 gsm.

(2) Once the slurry is added to the Buchner funnel, start the vacuum pump.

(3) Pay attention to the time it takes to drain the ingredients until they are "wet".

(4) Spray a known amount of the additive diluted suspension onto the surface of the wet pad. See Table 2 below.

(5) Continue to evacuate the wet sample for 10 seconds.

(6) Remove the wet pad from the Buchner funnel and place it between two sheets of absorbent paper. Roll the standard hand-held paper roller twice on the absorbent paper to compress the test sample.

(7) Take out the pressed sample and place it in a 100°C oven until dry.

Table 1—Internal Processing

In Table 1, additives are listed by weight percent on a dry basis.

Table 2—Spray Treatment

In Table 2, the additives are listed by weight % on a dry basis.

Based on experimental tests of the exemplary implementation, the data in Table 3 show the improvements achieved in water resistance and/or oil and grease resistance. Water resistance was tested using the water Cobb test, adapted from Tappi standard test method T 441om-20 "Water Absorption of Paper". Oil and grease resistance were tested using the 3M KIT test (Tappi standard test method T 559 "Oil Resistance") and the oil Cobb test, adapted from Tappi standard test method T 441om-20 using vegetable oil.

Table 3

While the basic novel features of this disclosure applied to its preferred and exemplary embodiments have been shown and described, it should be understood that those skilled in the art may omit, substitute, and change the form and details of this disclosure without departing from its spirit. Furthermore, it will be apparent to those skilled in the art that many modifications and variations will readily occur to them. For example, any feature of one or more embodiments may be applied to or combined with one or more other embodiments. Therefore, it is not intended to limit this disclosure to the exact structures and operations shown and described; thus, all suitable modified equivalents may be considered to fall within the scope of the claimed disclosure. In other words, although embodiments of this disclosure have been described with reference to the foregoing examples, it should be understood that modifications and variations are included within the spirit and scope of this disclosure. Therefore, the invention is limited only by the appended claims.

All references published in this article are incorporated herein by reference in their entirety.

Claims (46)

1. An improved cellulose nanofiber adhesive, comprising: Cellulose nanofibers (CNF); and SGF dopants that bind to this CNF, The SGF blend comprises one or more substances selected from sugar fatty acid esters (SFAEs), glycerides, fatty acid salts, natural waxes, and cellulose crosslinking agents. 2. The improved cellulose nanofiber binder according to claim 1, wherein the improved cellulose nanofiber binder is substantially composed of CNF and SGF admixtures. 3. The improved cellulose nanofiber binder according to claim 1, wherein the weight ratio of CNF to SGF dopant is 10:90 to 90:10. 4. The improved cellulose nanofiber binder according to claim 1, wherein the weight ratio of CNF to SGF dopant is 40:60 to 60:40. 5. The improved cellulose nanofiber adhesive according to claim 1, wherein the improved cellulose nanofiber adhesive is obtained by the following steps: To obtain an aqueous mixture of cellulose nanofibers (CNF); To obtain an aqueous SGF blend comprising one or more substances selected from sugar fatty acid esters (SFAEs), glycerides, fatty acid salts, natural waxes, and cellulose crosslinking agents; and Aqueous CNF mixtures are mixed with aqueous SGF blends and CNFs are combined with SGF blends to obtain improved cellulose nanofiber binders. 6. The improved cellulose nanofiber binder of claim 5 further comprises reducing the water content of CNF mixed with the aqueous SGF admixture. 7. The improved cellulose nanofiber adhesive according to claim 1, wherein the improved cellulose nanofiber adhesive is obtained by the following steps: To obtain an aqueous mixture of cellulose pulp; An aqueous SGF blend is obtained, the aqueous SGF blend comprising one or more substances selected from sugar fatty acid esters (SFAE), glycerides, fatty acid salts, natural waxes and cellulose crosslinking agents; A mixture of cellulose pulps is blended with an aqueous SGF blend to obtain a cellulose/SGF blend; and Exposing cellulose/SGF blends to mechanical shear forces yields an improved cellulose nanofiber binder. 8. The improved cellulose nanofiber binder of claim 7 further comprises pretreating the cellulose pulp before obtaining the cellulose/SGF mixture and/or before subjecting the cellulose/SGF mixture to mechanical shear forces. 9. A barrier formulation comprising the improved cellulose nanofiber binder according to claim 1. 10. A method for manufacturing cellulose-based articles, the method comprising: Add the improved cellulose nanofiber binder according to claim 1 to the aqueous papermaking ingredients; and Water is drained from the ingredients to obtain a fiber web. 11. The method of manufacturing a cellulose-based article according to claim 10, further comprising molding the fiber web into a molded article having a three-dimensional shape. 12. A method for imparting barrier properties to a cellulose-based material, comprising: Contact the cellulose-based material with an aqueous barrier agent for imparting barrier properties, the barrier agent comprising the improved cellulose nanofiber binder according to claim 1; and The barrier agent is bonded to the surface of the cellulose-based material to obtain a bonded cellulose-based material with barrier properties. The barrier properties are selected from one or more of water resistance, grease resistance and gas barrier properties. 13. A blocking agent comprising: The improved cellulose nanofiber adhesive according to claim 1; A second SGF blend comprising one or more substances selected from sugar fatty acid esters (SFAEs), glycerides, and fatty acid salts; and water. 14. The barrier formulation according to claim 13 further comprises one or more pigments. 15. A method for imparting barrier properties to a cellulose-based material, the method comprising: The cellulose-based material is contacted with a barrier agent used to impart barrier properties, the barrier agent comprising: Cellulose nanofibers (CNF) and SGF blends, wherein the SGF blend is selected from one or more of sugar fatty acid esters (SFAEs), glycerides, fatty acid salts, natural waxes, and cellulose crosslinking agents; and The barrier agent is bonded to the surface of a cellulose-based material to obtain a bonded cellulose-based material with barrier properties. The barrier properties are selected from one or more of water resistance, grease resistance and gas barrier properties. 16. The method of claim 15, wherein when the total weight of the blocking agent is considered to be 100% by weight, the blocking agent comprises about 4% by weight to about 96% by weight of CNF and about 4% by weight to about 96% by weight of SGF admixture. 17. The method of claim 15, wherein the cellulose-based material comprises cellulose fibers, and the contacting step comprises forming an aqueous mixture of the barrier agent and the cellulose fibers. 18. The method of claim 17, wherein the SGF blend is present in the aqueous mixture at a total concentration of at least 0.025% (by weight) of the total cellulose fibers present in the aqueous mixture. 19. The method of claim 17, wherein the aqueous mixture further comprises one or more pigments. 20. The method of claim 17, further comprising removing water from the aqueous mixture. 21. The method of claim 15, wherein the contacting step comprises coating the surface of a cellulose-based substrate with a formulation by means of impregnation, spraying, smearing, printing, or any combination of these methods. 22. The method of claim 20, wherein the SGF dopant is present on the substrate surface at a weight of at least about 0.05 g/ ^m² . 23. The method of claim 20, wherein the SGF dopant is present on the substrate surface at a weight of at least about 1 g/ ^m² . 24. The method of claim 21, wherein the cellulose-based substrate is a surface selected from the following articles: paper, paperboard, bacon slabs, insulating materials, pulp, cartons for food storage, compost bags, bags for food storage, release paper, transport bags, fabrics or films that prevent/block grass, mulch film, flower pots, packaging beads, bubble wrap outer packaging, oil-absorbing materials, laminates, envelopes, gift cards, credit cards, gloves, raincoats, OGR paper, shopping bags, diapers, diapers, tableware, tea bags, containers for coffee or tea, containers for holding hot... Containers for drinking or cold beverages, cups, plates, bottles for storing carbonated liquids, bottles for storing non-carbonated liquids, caps, food packaging films, waste disposal containers, food handling tools, textile fibers, water storage and conveying equipment, storage and conveying equipment for alcoholic or non-alcoholic beverages, casings or screens of electronic products, internal or external components of furniture, curtains, interior decoration, fabrics, films, boxes, sheets, trays, pipes, water pipes, clothing, medical devices, pharmaceutical packaging, contraceptives, camping equipment, molded cellulose materials and combinations thereof. 25. The method of claim 15, wherein the cellulose-based material with barrier properties exhibits a contact angle equal to or greater than 90°. 26. The method of claim 15, wherein the cellulose-based material with barrier properties exhibits a TAPPI T 559KIT test value of 3 to 12. 27. The method of claim 15, wherein the combined cellulose-based material exhibits a water contact angle equal to or greater than 90° and/or a TAPPI T 559KIT test value of 3 to 12 in the absence of any second hydrophobic material. 28. A method for manufacturing an improved cellulose nanofiber binder, the method comprising: To obtain an aqueous mixture of cellulose nanofibers (CNF); To obtain an aqueous SGF blend comprising one or more substances selected from sugar fatty acid esters (SFAEs), glycerides, fatty acid salts, natural waxes, and cellulose crosslinking agents; and Aqueous CNF mixtures are blended with aqueous SGF blends to obtain CNF/SGF blends, and CNF is combined with SGF blends to obtain improved cellulose nanofiber binders. 29. The method of manufacturing an improved cellulose nanofiber binder according to claim 28, further comprising reducing the water content of the CNF/SGF mixture. 30. A method for manufacturing an improved cellulose nanofiber adhesive, the method comprising: To obtain an aqueous mixture of cellulose pulp; An aqueous SGF blend is obtained, the aqueous SGF blend comprising one or more substances selected from sugar fatty acid esters (SFAE), glycerides, fatty acid salts, natural waxes and cellulose crosslinking agents; An aqueous mixture of cellulose pulp is blended with an aqueous SGF blend to obtain a cellulose/SGF blend; and Exposing cellulose/SGF blends to mechanical shear forces yields an improved cellulose nanofiber binder. 31. The method of manufacturing an improved cellulose nanofiber binder according to claim 30, further comprising pretreating the cellulose pulp before obtaining the cellulose/SGF mixture and/or before subjecting the cellulose/SGF mixture to mechanical shear forces. 32. A method for manufacturing a molded article, the method comprising: A forming tool having a three-dimensional shape including a forming portion is provided, the forming portion being brought into contact with a cellulose composition such that the forming portion is covered by a layer of wet pulp; and the pulp layer on the forming tool is dehydrated to obtain a molded article. The cellulose composition comprises cellulose pulp and the improved cellulose nanofiber binder according to claim 1. 33. The method of manufacturing a molded article according to claim 32, wherein the dehydration is carried out at a temperature >100°C to obtain a dry content of at least 70% by weight. 34. A molded article obtained by the method according to claim 32. 35. The molded article of claim 34, wherein the three-dimensional shape is selected from bowls, cups, plates, forks, spoons and knives. 36. The method of manufacturing a molded article according to claim 32, further comprising coating the surface of the molded article with a barrier agent comprising a second SGF blend by means of dipping, spraying, smearing, printing, or any combination of these methods, the second SGF blend comprising one or more substances selected from sugar fatty acid esters (SFAEs), glycerides, and fatty acid salts. 37. A molded article obtained by the method according to claim 36. 38. The molded article of claim 37, wherein the three-dimensional shape is selected from bowls, cups, plates, forks, spoons and knives. 39. A method for manufacturing a molded article, the method comprising: A forming tool having a three-dimensional shape including a forming portion is provided, the forming portion being brought into contact with a cellulose composition such that the forming portion is covered by a layer of wet pulp; and the pulp layer on the forming tool is dehydrated to obtain a molded article. The cellulose composition comprises cellulose pulp and a barrier agent according to claim 9. 40. The method of manufacturing a molded article according to claim 39, wherein the dehydration is carried out at a temperature >100°C to obtain a dry content of at least 70% by weight. 41. A molded article obtained by the method according to claim 39. 42. The molded article of claim 41, wherein the three-dimensional shape is selected from bowls, cups, plates, forks, spoons and knives. 43. A method for manufacturing a molded article, the method comprising: A forming tool having a three-dimensional shape including a forming portion is provided, the forming portion being brought into contact with a cellulose-based material such that the forming portion is covered by a wet pulp layer; the pulp layer on the forming tool is dehydrated to obtain an intermediate molded article; and the surface of the intermediate molded article is coated with a barrier agent according to claim 9 by means of impregnation, spraying, smearing, printing or any combination of these methods to obtain a molded article. 44. The method of claim 43 further comprises reducing the water content of the intermediate molded article coated with the barrier agent. 45. A molded article obtained by the method according to claim 43. 46. The molded article of claim 45, wherein the three-dimensional shape is selected from bowls, cups, plates, forks, spoons, and knives.