JP7833463B2 - Reinforced cellulose nanofibril (CNF) - Google Patents

Description

This disclosure relates to reinforced cellulose nanofibrils (CNF) (or reinforced CNF binders), methods for producing reinforced CNF binders, methods for producing wet-laid articles, dry-laid articles, or molded articles having a reinforced CNF binder by incorporating the reinforced CNF into the finished paper stock at the wet end of a papermaking process, methods for coating cellulose-based materials, intermediate-forming fibrous articles, and/or molded articles with a reinforced CNF binder, and cellulose-based articles obtained by these methods, wherein the reinforced CNF comprises a blend of sugar fatty acid esters, glycerides, fatty acid salts, natural waxes, and/or cellulose crosslinking agents (SGFs) bound to the CNF.

Cellulosic materials have a wide range of industrial applications as fillers, absorbents, and printing components. These uses are preferred over other material sources due to their high thermal stability, good oxygen barrier function, and chemical/mechanical resilience (see, for example, Aulin et al., Cellulose (2010) 17:559–574, which is all incorporated herein by reference). The fact that these materials are completely biodegradable when dispersed in the environment and are completely non-toxic is also of great importance. Cellulose and its derivatives are materials adopted as environmentally friendly solutions in applications such as food packaging and disposable item packaging.

On the other hand, 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 easily hydrated (see, for example, Aulin et al., Langmuir (2009) 25(13):7675–7685, all of which are incorporated herein by reference). While this is beneficial for applications such as absorbents and tissues, it becomes problematic when the secure packaging of materials containing moisture/lipids (e.g., food) is required. Long-term storage of food, particularly cooked foods containing large amounts of water and/or fat, presents problems, for example, in cellulose trays, because cellulose trays can first become soggy and then eventually cease to function. Furthermore, due to the high relative porosity of the material, multiple coatings are required to compensate for the low efficiency in maintaining sufficient coating on cellulosic surfaces, thus increasing costs.

Such problems are typically addressed industrially by coating cellulose fibers with certain hydrophobic organic materials/fluorocarbons (e.g., perfluoroalkyl and polyfluoroalkyl materials (PFAS)), waxes, synthetic polymers (e.g., polyethylene), or silicones to physically shield the underlying hydrophilic cellulose from water/lipids in its contents. This includes preventing wicking in the fiber gaps, i.e., preventing grease from seeping into the folds, or allowing the release of the attached material. For example, materials such as PVC/PEI/PE are routinely used for this purpose and are physically applied to the surface to be treated (i.e., by spray coating or extrusion).

Industrially, due to fluorocarbons' ability to reduce the surface energy of articles, compounds based on the chemical action of fluorocarbons have long been used to produce articles with improved resistance to oil and grease penetration. One new problem with the use of perfluorinated hydrocarbons is their high persistence in the environment. The EPA and FDA have recently begun re-examining the sources, environmental fate, and toxicity of these compounds. Recent studies have reported extremely high incidence rates (over 90%) of perfluorooctanesulfonates in blood samples taken from school students. The cost and potential environmental responsibility of these compounds are prompting manufacturers to seek alternative means of producing articles resistant to oil and grease penetration.

While lowering surface energy improves the penetrating resistance of an article, it also has several drawbacks. For example, textile fabrics treated with fluorocarbons exhibit good stain resistance, but once soiled, the ability of cleaning compositions to penetrate and release the stain from the fabric may be affected, potentially leading to a reduced lifespan and permanently soiled fabric. Another example is grease-resistant paper intended for later printing and/or adhesive coating. In this case, the required grease resistance can be achieved through fluorocarbon treatment, but the paper's low surface energy can lead to problems related to the acceptance of printing inks or adhesives, including scuffing, back-trap mottling, poor adhesion, and registration issues. When grease-resistant paper is intended for use as a pressure-sensitive label with adhesive applied to one side, the low surface energy can reduce adhesive strength. To improve these printability, coating capabilities, or adhesion, articles with low surface energy can be treated with post-processing such as corona discharge, chemical treatment, or flame treatment. However, these processes increase the manufacturing cost of the article and have other drawbacks.

It is desirable to design a hydrophobic, oleophobic, and compostable "green" bio-based coating that includes a base paper/film that can maintain the coating on the paper surface and prevent wicking into the fiber gaps, or reduce the adhesion of materials to cellulosic surfaces, without sacrificing biodegradability and/or recyclability, at a reduced cost.

Another problem is that conventional coatings for imparting hydrophobic and/or oleophobic barrier properties, including fluorocarbon and petrochemical coatings as described herein, tend to perform poorly at folds, creases, and other points where the material is coated. Specifically, these articles typically exhibit poor water and/or grease resistance at these points. Such a “grease creasing effect” can be defined as the sorption of grease into a paper structure, resulting from folding, pressing, or crushing the paper structure. Conventional solutions to the grease creasing effect involve adding latex, polyvinyl alcohol, or similar resins to the coating to improve coverage at these points. However, such conventional solutions may still result in water and/or oil and grease resistance at these points being inferior to that of flat parts of the article, increase costs due to the addition of resin components, and are not entirely bio-based, as latex and polyvinyl alcohol are synthetic and/or not readily recyclable.

U.S. Patent Application Publication No. 2018/0066073 (hereinafter, “'073 Publication”), which is entirely incorporated herein by reference, discloses a modifiable method for treating cellulosic materials with compositions that result in increased barrier properties, such as water resistance and/or oil and grease resistance (OGR), without sacrificing their biodegradability. In particular, the '073 Publication discloses a method for bonding sugar fatty acid esters ("SFAEs") onto cellulosic materials to provide treated materials exhibiting higher water resistance, lipid resistance, barrier function, and other mechanical properties.

U.S. Provisional Patent Application Publication No. 63/022,097, filed 8 May 2020 (hereinafter, the “‘097 Application”), which is entirely incorporated herein by reference, discloses a modifiable method for treating cellulosic materials with compositions that provide increased barrier properties, such as water resistance and/or OGR resistance, without sacrificing their biodegradability. In particular, the ‘097 Application discloses a method for combining blends of glycerides and/or fatty acid salts. The ‘097 Application also discloses that barrier formulations comprising blends of glycerides and/or fatty acid salts may further contain SFAEs to impart water resistance and/or OGR resistance, and/or provide emulsifier functionality.

PCT/US2020/014923 (hereinafter, “'923 Application”), which is entirely incorporated herein by reference, discloses a method for treating fibrous cellulosic materials with sucrose fatty acid ester-containing particles (carrier system) that enable surface modification, including producing such surface water resistance and/or oil/grease resistance. The disclosed method provides for forming micelle particles by combining at least one SFAE with a polymer (e.g., latex), and for coating such particles onto a substrate containing a fibrous cellulose-based material (e.g., pulp) to form, in particular, a molded product. Compositions comprising a combination of SFAE, latex, and optionally minerals or other additives are also disclosed.

US 16/568,953 (hereinafter, the “‘953 application”), which is entirely incorporated herein by reference, discloses a modifiable method for treating cellulosic materials with a barrier coating comprising prolamin and at least one polyol fatty acid ester, which imparts increased oil and/or grease resistance to such materials without sacrificing their biodegradability. The disclosed method provides adhesion of the barrier coating to articles containing cellulosic materials and articles containing articles produced by such method. Materials thus treated exhibit higher oleophobicity and can be used in any application where such characteristics are desired.

US 16/456,499 (hereinafter, “'499 Application”), which is entirely incorporated herein by reference, discloses a modifiable method for treating cellulosic materials with a barrier coating comprising at least two polyols and/or sugar fatty acid esters, which imparts increased water resistance, oil resistance, and grease resistance to such materials without sacrificing their biodegradability. The disclosed method provides adhesion of the barrier coating to articles containing cellulosic materials and articles containing articles produced by such method. Materials thus treated exhibit higher hydrophobicity and oleophobicity and can be used in any application where such characteristics are desired.

US 16/456,433 (hereinafter, “'433 application”), which is entirely incorporated herein by reference, discloses a method for treating cellulosic materials with a composition that enables greater retention of inorganic particles on a cellulosic substrate. The disclosed method provides combining SFAE with such inorganic particles and applying such combination to a cellulosic material to eliminate or reduce the use of retention aids or binders for fillers in papermaking processes. Compositions containing such combinations of SFAE and inorganic particles are also disclosed.

The use of binders derived from natural sources is also becoming increasingly important in providing "green" bio-based products.

Nanocellulose is a term referring to nanostructured cellulose, which may be cellulose nanocrystals (CNC or NCC), cellulose nanofibrils (CNF) (also referred to in this art as cellulose nanofibers and nanofibrillated cellulose), or bacterial nanocellulose.

CNF is a material composed of nano-sized cellulose fibrils, typically having a high aspect ratio (length-to-width ratio). CNF is typically obtained from wood pulp or another natural cellulose fiber source by a process that typically involves subjecting the pulp/fibers to mechanical shear forces.

CNF has been used as a binder in the papermaking process. The inventors determined that the use of CNF as an additive in wet-end and coating applications could improve OGR (Oral Gross Reaction). However, the use of CNF presents certain problems. One problem is that when CNF is used as a wet-end additive to the finished paper stock, it tends to slow the drainage rate (or dewatering) of the fiber mat from the slurry. This is detrimental, for example, because the rate of water removal affects the production rate of cellulose-based products. Another problem is that CNF tends to agglomerate when used as an additive in slurry or spray, which can negatively impact its efficiency and/or functional properties.

Thus, there is still a need for "green" bio-based coatings for cellulose-based materials that provide improved water resistance and/or OGR resistance, as well as for "green" cellulose-based molded articles with improved water resistance and/or OGR resistance.

This disclosure provides a method for addressing one or more of the limitations and/or concerns of the prior art described above, and/or providing one or more improvements thereto. However, this disclosure does not need to address any of the limitations and/or concerns.

In one embodiment, the present disclosure relates to a reinforced cellulose nanofibril binder comprising cellulose nanofibrils (CNF) and an SGF blend bound to the CNF, wherein the SGF blend comprises one or more selected from the group consisting of sugar fatty acid esters (SFAEs), glycerides, fatty acid salts ("FAS"), natural waxes, and cellulose crosslinking agents.

In this specification, “SGF blend” means one or more sugar fatty acid esters (SFAEs), and/or one or more glycerides, and/or one or more fatty acid salts (FASs), 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 contain SFAEs; in some embodiments, the SGF blend does not contain glycerides; in some embodiments, the SGF blend does not contain FASs; in some embodiments, the SGF blend does not contain natural waxes; and in some embodiments, the SGF blend does not contain cellulose crosslinking agents. In some embodiments, the SGF blend essentially consists of SFAEs, glycerides, and/or FASs. In some embodiments, the SGF blend consists of SFAEs, glycerides, and/or FASs.

The reinforced cellulose nanofibril binder (or reinforced CNF) described herein can offer certain advantages. For example, when used in the finished paper stock at the wet end of a papermaking process, the reinforced CNF maintains or increases the drainage rate of the fibrous mat from the slurry. Furthermore, the reinforced CNF does not suffer from the agglomeration problems associated with conventional CNF.

In one aspect of this disclosure, the reinforced cellulose nanofibril binder essentially consists of a CNF and SGF blend.

In another embodiment of the reinforced cellulose nanofibril binder, the weight ratio of CNF to SGF blend is approximately 1:99 to approximately 99:1, or approximately 5:95 to approximately 95:5, or approximately 10:90 to approximately 90:10, or approximately 15:85 to approximately 85:15, or approximately 20:80 to approximately 80:20, or approximately 25:75 to approximately 75:25, or approximately 30:70 to approximately 70:30, or approximately 35:65 to approximately 65:35, or approximately 40:60 to approximately 60:40, or approximately 45:55 to approximately 55:45, or approximately 50:50.

In one embodiment, a reinforced cellulose nanofibril binder is obtained by a method comprising the steps of: obtaining an aqueous mixture of cellulose nanofibrils (CNF); obtaining an aqueous SGF blend; and mixing the aqueous mixture of CNF with the aqueous SGF blend to obtain a CNF/SGF mixture. The mixing of CNF and SGF blend (thus contacting CNF with the SGF blend) may be sufficient to bind the SGF blend to the CNF. Alternatively, the SGF blend can be bound to the CNF by exposing the CNF/SGF mixture to heat, radiation, a catalyst, or a combination thereof for a sufficient period of time. This method may further include the step of reducing the water content of the CNF/SGF mixture, for example, by draining the water.

In one embodiment, the reinforced cellulose nanofibril binder according to this disclosure is obtained by a method comprising the steps of: obtaining an aqueous mixture of cellulose pulp (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; and subjecting the cellulose/SGF mixture to mechanical shear force to obtain a reinforced cellulose nanofibril binder.

In one embodiment, a method for obtaining reinforced CNF may further include the step of reducing the water content of the cellulose/SGF mixture by draining the water.

In one embodiment, a method for obtaining reinforced CNF may further include a step of pre-treating the cellulose pulp before obtaining the cellulose/SGF mixture and/or before subjecting the cellulose/SGF mixture to mechanical shear forces.

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

In one embodiment, the Disclosure provides a barrier formulation comprising reinforced CNF according to the Disclosure. The composition of the barrier formulation can be selected to allow the cellulose-based material to be configurably derivatized by methods known in the Art, such as Publication '073 or Application '097.

In one embodiment, the present disclosure provides a method for producing a cellulose-based article, comprising the steps of adding a reinforced cellulose nanofibril binder according to the present disclosure to an aqueous papermaking pulp, and draining water from the pulp to obtain a fibrous web.

In one embodiment, such a method further includes the step of forming a fibrous web into a molded article having a three-dimensional shape.

In one embodiment, a method is provided for imparting barrier properties to a cellulose-based material, comprising the steps of: contacting the cellulose-based material with an aqueous barrier formulation to impart barrier properties, wherein the barrier formulation comprises the reinforced cellulose nanofibril binder according to this disclosure; and bonding the barrier formulation to the surface of the cellulose-based material to obtain a bonded cellulose-based material having barrier properties, wherein the barrier properties are one or more selected from the group consisting of water resistance, lipid resistance, and gas resistance.

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

In one embodiment, the second SGF blend of the barrier formulation can be selected to allow the cellulose-based material to be configurably derivatized by methods known in the art, such as those published in '073 or application '097.

In one embodiment, the barrier formulation of this disclosure may contain pigments conventionally used in the papermaking industry.

In one embodiment, a method for imparting barrier properties to a cellulose-based material comprises the steps of: contacting the cellulose-based material with a barrier formulation to impart barrier properties, wherein the barrier formulation comprises (a) cellulose nanofibril (CNF) and (b) an SGF blend; and bonding the barrier formulation to the surface of the cellulose-based material to obtain a bonded cellulose-based material having barrier properties, wherein the barrier properties are one or more selected from the group consisting of water resistance, lipid resistance, and gas resistance.

The method for imparting barrier properties according to this disclosure may provide similar benefits to those previously mentioned, including maintaining or increasing the drainage rate and preventing CNF agglomeration when the method is applied to a wet-end process.

In one embodiment, when the total weight of the barrier formulation used in the method for imparting barrier properties according to this disclosure is considered to be 100% by weight, the barrier formulation comprises approximately 4% to approximately 96% by weight of CNF and approximately 4% to approximately 96% by weight of SGF blend.

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

In one embodiment, the SGF blend can be present in an aqueous mixture or dispersion at a total concentration of at least 0.025% (wt/wt) of the total cellulose fibers present in the aqueous mixture.

In one embodiment, the aqueous mixture contains one or more pigments conventionally used in the papermaking industry.

In one embodiment, 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 embodiment, such a method further includes the step of reducing the water content of the aqueous mixture, such as by draining the water.

In another embodiment, the contact step in the method for imparting barrier properties according to the present disclosure includes coating the surface of a cellulose-based substrate with the formulation by dipping, spraying, painting, printing, or any optional combination of these processes.

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

Cellulose-based substrates are not particularly limited. In one embodiment, examples of cellulose-based substrates include paper, cardboard, bacon board, insulating materials, papermaking pulp, food storage cartons, compost bags, food storage bags, release paper, transport bags, weed block/barrier fabrics or films, mulching films, flower pots, packing beads, bubble wrap, oil absorbent materials, laminates, envelopes, gift cards, credit cards, gloves, raincoats, OGR paper, shopping bags, diapers, membranes, tableware, tea bags, containers for coffee or tea, containers for holding hot or cold beverages, cups, plates, carbonated drinks. Examples include bottles for liquid storage, bottles for non-carbonated liquid storage, lids, films for food packaging, waste disposal containers, food handling equipment, fabric fibers, water storage and transport equipment, storage and transport equipment for alcoholic or non-alcoholic beverages, outer casings or screens for electronic products, interior or exterior components of furniture, curtains, upholstery items, fabrics, films, boxes, sheets, trays, pipes, water conduits, clothing, medical devices, pharmaceutical packaging, contraceptives, camping equipment, molded cellulosic materials, and surfaces of articles selected from combinations thereof.

In one embodiment, the method for imparting barrier properties according to this disclosure provides a bound cellulose-based material exhibiting a water contact angle of 90° or more.

In one embodiment, the method for imparting barrier properties according to this disclosure provides a bound cellulose-based material exhibiting TAPPI T 559 KIT test values 3 to 12.

In one embodiment, a method for imparting barrier properties according to this disclosure provides a bound cellulose-based material exhibiting a water contact angle of 90° or greater and/or a TAPPI T 559 KIT test value of 3 to 12 in the absence of secondary hydrophobic substances.

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

In one embodiment, a method for producing reinforced CNF further includes the step of reducing the water content of the CNF/SGF mixture.

In one embodiment, a method for producing a reinforced cellulose nanofibril binder is provided, comprising the steps of: 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; and subjecting the cellulose/SGF mixture to mechanical shear force to obtain a reinforced cellulose nanofibril binder.

In one embodiment, such a method includes a step of pretreatment of cellulose pulp before obtaining a cellulose/SGF mixture and/or before subjecting the cellulose/SGF mixture to mechanical shear forces.

In one embodiment, a method for producing a molded article is disclosed, comprising the steps of: providing a forming tool having a three-dimensional shape with a forming portion; contacting the forming portion with a cellulose composition such that the forming portion is covered with a wet layer of pulp; and dewatering the pulp layer on the forming tool to obtain a molded article, wherein the cellulose composition comprises cellulose pulp and a reinforced cellulose nanofibril binder according to this disclosure.

In one embodiment, a method for producing a molded article is disclosed, comprising the steps of: providing a forming tool having a three-dimensional shape with a forming portion; bringing the forming portion into contact with a cellulose composition such that the forming portion is covered with a wet layer of pulp; and dewatering the pulp layer on the forming tool to obtain a molded article, wherein the cellulose composition comprises cellulose pulp and a barrier compound according to this disclosure.

In one embodiment, a method for producing a molded article is disclosed, comprising the steps of: providing a forming tool having a three-dimensional shape with a forming portion; contacting the forming portion with a cellulose composition such that the forming portion is covered with a wet layer of pulp; 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 formulation according to this disclosure by dipping, spraying, painting, printing, or any optional combination thereof to obtain a molded article.

In one embodiment, a method for producing a molded article includes the step of dehydrating at a temperature exceeding 100°C to achieve a dry content of at least about 70% by weight, preferably at least about 80% by weight.

In one embodiment, the pulp layer present on the molding tool is dewatered by press drying carried out at a temperature exceeding 100°C, preferably at a temperature of about 120 to 250°C, or more preferably at a temperature of about 150 to 220°C.

In one embodiment, a cellulose composition for a method of producing a molded article comprises a fibrous mixture essentially consisting of chemothermetic pulp (CTMP), thermomechanical pulp (TMP), chemical pulp or semi-chemical pulp, or a combination thereof. The pulp may be bleached or unbleached.

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

In one embodiment, a method for producing a molded article further includes coating the surface of the molded article with a barrier formulation containing an SGF blend by dipping, spraying, painting, printing, or any optional combination of these processes.

In one embodiment, the surface coating of the molded article with a barrier compound is performed while the molded article is an intermediate molded article having a relatively high moisture content and a fiber content of approximately 20-50% by weight, preferably approximately 30-40% by weight.

In one embodiment, this disclosure provides a cellulose-based product obtained by any of the methods described herein, which is a three-dimensional molded product, such as a food packaging molded product, made from cellulose fibers.

In one embodiment, the three-dimensional shape obtained by the method for manufacturing a molded product is not particularly limited.

In one embodiment, the three-dimensional shape is, for example, the shape of a bowl, cup, plate, fork, spoon, or knife.

In some embodiments, the barrier formulation essentially consists of a CNF and SGF blend.

In some embodiments, the weight ratio of CNF to SGF blend in the barrier formulation is approximately 20:1 to approximately 1:5. In some embodiments, the weight ratio may be approximately 5:1 to approximately 1:5.

In some embodiments, when the total weight of the barrier formulation is considered to be 100% by weight, the barrier formulation contains about 4% to about 96% by weight of CNF and about 4% to about 96% by weight of SGF blend. In some embodiments, the amount of CNF may be about 10% to about 70% by weight. In some embodiments, the amount of SGF blend may be about 30% to about 90% by weight.

In some embodiments, the barrier formulation further comprises one or more prolamins.

In some embodiments, one or more prolamins are selected from wheat (gliadin), barley (hordein), rye (secalin), corn (zein), sorghum (caphirin), and/or oats (avenin).

In some embodiments, the cellulose-based material contains cellulose fibers suitable for papermaking, and the aqueous mixture or dispersion is the finished paper stock or raw material.

In some embodiments, the molded article exhibits a water contact angle of 90° or more, 100° or more, 110° or more, or 120° or more.

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

In some embodiments, the molded article exhibits reduced permeability to gases (also referred to as "gas resistance") (e.g., resistance to oxygen, nitrogen, and carbon dioxide). In some embodiments, gas resistance is reduced permeability to oxygen.

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

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

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

In another embodiment, a method is provided for producing a cellulose-based product having barrier properties, comprising the steps of: obtaining a finished pulp containing an aqueous mixture of cellulose fibers; adding an SGF blend to the finished pulp; adding CNF to the finished pulp; and adding a retention aid to the finished pulp to assist in the retention of the SGF blend on the cellulose fibers.

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

In some embodiments, the charged polymer comprises one or more cationic polymers. The one or more cationic polymers may include polyacrylamide. The polyacrylamide may include poly-DADMAC (polydiallyldimethylammonium chloride) or alum (aluminum sulfate).

In some embodiments, one or more prolamins may be added to the wet end to assist in the retention of the SGF blend, CNF, and/or reinforced CNF on the cellulose-based material.

Before describing in more detail the compositions, methods, and methodologies according to the present invention, it should be understood that this disclosure is not limited to the specific compositions, methods, and experimental conditions described herein, and that the compositions, methods, and conditions may vary. Furthermore, it should be understood that the scope of the present invention is limited only to the appended claims, and that the terms used herein are intended solely to describe specific embodiments and are not intended to limit them.

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

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those generally understood by those skilled in the art in which this disclosure pertains. Since variations and modifications are understood to be included within the spirit and scope of this disclosure, any methods and materials similar or equivalent to those described herein may be used in the practice or testing of this disclosure.

This disclosure provides a reinforced cellulose nanofibril binder.

Cellulose nanofibrils (also referred to herein as CNF) and methods for producing them are well known in the art.

The CNF for use in the embodiments of this disclosure is not particularly limited. CNF may be commercially obtained or produced by known methods, typically involving subjecting a cellulose fiber source (e.g., wood pulp) to mechanical shear forces.

The properties of CNF are not particularly limited. CNF may have a typical fibril width of about 5 to 20 nanometers and a length of several micrometers.

In some embodiments, reinforced CNF is obtained by contacting conventionally produced CNF with an SGF blend, thereby binding the SGF blend to the CNF. In another embodiment, reinforced CNF is obtained by subjecting a cellulose fiber source (e.g., wood pulp) to mechanical shear stress while the CNF is mixed with the SGF blend.

As described above, reinforced CNF offers advantages over conventionally used CNF, such as maintaining or increasing the drainage rate of the fiber mat from the slurry and reducing CNF agglomeration.

This disclosure provides methods for imparting barrier properties to cellulose-based materials. These methods include the steps of: contacting the cellulose-based material with a barrier formulation to impart barrier properties; and bonding the barrier formulation to the surface of the cellulose-based material to obtain a bonded cellulose-based material having barrier properties, wherein the barrier properties are one or more selected from the group consisting of water resistance, gas resistance, and lipid resistance. The barrier formulation may contain reinforced CNF, or the barrier formulation may contain a reinforced CNF and SGF blend.

The methods of this disclosure can provide solvent-free, bio-based, high-temperature resistant barriers (or barrier coatings) against oils and greases (OGRs), water, and/or gases (e.g., oxygen, nitrogen, and carbon dioxide), and/or formed fiber (e.g., molded) products having these properties.

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

In some embodiments, reinforced CNF can be used at the wet end of the papermaking process by directly adding it to the finished paper stock. Alternatively, in another embodiment, similar benefits can be obtained by directly adding a combination of CNF and SGF blend to the finished paper stock.

One or more charged polymers, such as poly-DADMAC or polyacrylamide, can also be added to the finished pulp as retention aids to promote the absorption of the SGF blend and/or CNF onto the cellulose surface. In some embodiments, the charged polymer can be used to control the electrostatic charge of the SGF blend-containing formulation.

In another embodiment, prolamin can be used as a binder. This is described, for example, in U.S. Provisional Application No. 63/044,820, filed June 26, 2020 (hereinafter, the “‘820 Application”), which is entirely part of this specification by reference.

Prolamin can be used not only as a binder for SGF blends and/or CNF, but also as a binder for conventional pigments added to finished paper stocks. Pigments are typically relatively small and charged on their surfaces, including their edges. Therefore, pigments can be easily trapped (and thereby selectively retained) within the prolamin matrix.

In addition to direct addition to the finished paper pulp, the barrier formulation can be coated onto cellulose-based materials or substrates (e.g., already formed paper products) by dipping, spraying, painting, printing, extrusion coating, weighing, or any optional combination of these processes. The barrier formulation may contain a sufficient amount of reinforced CNF to impart the desired water resistance and/or OGR to the cellulose-based material.

Alternatively, the barrier formulation may contain a suitable amount of CNF and SGF blend to impart the desired water resistance and/or OGR to the cellulose-based material.

Alternatively, the barrier formulation may contain a suitable amount of reinforced CNF and SGF blend to impart the desired water resistance and/or OGR to the cellulose-based material.

In this disclosure, the interaction between the SGF blend and CNF may be ionic, hydrophobic, van der Waals interaction, covalent bonding, or a combination thereof. In this specification, “bonding,” including its grammatical variations, means to aggregate or cause aggregation as essentially a single mass, and may refer to ionic, hydrophobic, van der Waals interaction, or covalent bonding, or a combination thereof.

In this disclosure, the interaction between the SGF blend and the cellulose-based material may be ionic, hydrophobic, van der Waals interaction, covalent bonding, or a combination thereof.

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

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

In this specification, “cellulose-based” means 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 produce such objects, films, or filaments that are structurally and functionally similar to cellulose, for example, coatings and adhesives (e.g., _{carboxymethylcellulose} ). Another example is cellulose, which is a complex carbohydrate ( _C6H10O5 ) _n composed of glucose units that forms the main component of _the cell walls of most plants.

The cellulosic materials (or cellulose-based materials) described herein may, for example, be cellulose fibers, microfibrillated cellulose (MFC), nanofibrillated cellulose (or CNF), or cellulose nanocrystals, as conventionally used in the paper industry.

In this specification, "coating weight" refers to the weight (wet or dry) of the material to be applied to the substrate. This is expressed in pounds per strip or grams per square meter.

In this specification, "effect" means conferring a particular property to a particular material, including its grammatical variations.

In this specification, "hydrophobic substance" means a substance that does not attract water. For example, waxes, rosin, resins, sugar fatty acid esters, fatty acid salts, glycerides, diglycerides and triglycerides with long fatty acid chains, diketene, shellac, vinyl acetate, PLA, PEI, oils, fats, lipids, other water-repellent chemicals, or combinations thereof are hydrophobic substances.

In this specification, "hydrophobic" refers to a property that repels water and does not tend to absorb it.

In this specification, "lipid resistance" or "oleophobicity" refers to the property of repelling lipids, greases, fats, etc., and not absorbing them. In relevant embodiments, grease resistance can be measured by the "3M KIT" test, the TAPPI T559 Kit test, or the Cobb oil test.

In this specification, “cellulose-containing material” or “cellulose-based material” means a composition essentially made of cellulose. Examples of such materials include, but are not limited to, paper, paper sheets, cardboard, papermaking pulp, food storage cartons, parchment, cake board, meat wrapping paper, release paper/liner for pressure-sensitive adhesives, food storage bags, shopping bags, transport bags, bacon board, insulating materials, tea bags, coffee or tea containers, compost bags, tableware, containers for holding hot or cold beverages, cups, lids, plates, bottles for storing carbonated liquids, gift cards, bottles for storing non-carbonated liquids, food packaging films, waste disposal containers, food handling utensils, fabric fibers (e.g., cotton or cotton blends), water storage and transport equipment, alcoholic or non-alcoholic beverages, outer casings or screens for electronic products, interior or exterior components of furniture, curtains, and upholstery items.

In this specification, “fibers in solution” or “pulp” means lignocellulosic fibrous materials prepared by chemically or mechanically separating cellulose fibers from wood, fiber crops, or waste paper. In relevant embodiments, when cellulose fibers are treated by the methods described herein, the cellulose fibers themselves contain the bound SFAE, glycerides, and/or FAS as separated entities, and the bound cellulose fibers have distinct properties from free fibers (for example, pulp fibers or cellulose fibers or nanocellulose or microfibrillated cellulose SFAE blend bound materials will not form hydrogen bonds between fibers as easily as unbound fibers).

In this specification, “repulpable” means producing a paper or cardboard product suitable for crushing into a soft, formless mass for reuse in the manufacture of paper or cardboard.

In this specification, “adjustable” means adjusting or adapting a method to achieve a particular result, including its grammatical variations.

In this specification, "water contact angle" refers to the angle measured through a liquid at which the liquid/vapor interface encounters a solid surface. This quantifies the wettability of a solid surface by a liquid. The contact angle reflects the strength of the interaction between liquid and solid molecules compared to the strength of their interaction with each other. On many highly hydrophilic surfaces, water droplets exhibit contact angles between 0° and 30°. Generally, a water contact angle greater than 90° indicates a hydrophobic solid surface. The water contact angle can be easily obtained using an optical tension meter (see, for example, Dyne Testing, Staffordshire, and United Kingdom).

In this specification, "water vapor permeability" refers to the breathability, or the ability of a textile to move moisture. There are at least two different measurement methods. One of these, the MVTR test (water vapor transmission rate) according to ISO 15496, represents the water vapor permeability (WVP) of a fabric, and therefore the degree to which sweat is transported to the outside air. The measurement determines the number of grams of moisture (water vapor) that pass through one square meter of fabric in 24 hours (higher levels indicate higher breathability).

In one embodiment, water resistance can be determined using the TAPPI T 530 Hercules sizing test (i.e., a paper sizing test by ink resistance). Ink resistance by the Hercules method is best classified as a direct measurement test of penetration. Alternatively, this is classified as the rate of penetration testing. There is no single best test for "measuring sizing." The choice of test depends on the final use and the need for mill control. This method is particularly suitable for use as a mill-controlled sizing test to accurately detect changes in sizing levels. It provides the sensitivity of an ink float test while yielding reproducible results, shorter test times, and automatic endpoint determination.

Sizing, measured by the paper's resistance to the permeation or absorption of water-based liquids, is a key property of many types of paper. Typical examples include bags, container board, food wrap, document paper, and several print grades.

This method can be used to monitor the production of paper or cardboard for specific end uses, provided that an acceptable correlation is established between the test values and the paper's final use performance. Due to the nature of the test and the impregnated material, this correlation may not be sufficient to be applicable to all end-use requirements. This method measures sizing by impregnation rate. Other methods measure sizing by surface contact, surface penetration, or absorption. Sizing tests are selected based on their ability to simulate the means of water contact or absorption in the end use. This method can also be used to optimize the cost of sizing chemicals.

In this specification, “oxygen permeability” means the degree to which a polymer allows the passage of a gas or fluid. The oxygen permeability (Dk) of a material is a function of diffusivity (D) (i.e., the rate at which oxygen molecules traverse the material) and solubility (k) (or the amount of oxygen molecules absorbed per unit volume in the material). The value of oxygen permeability (Dk) typically falls within the range of 10 to 150 × ^10⁻¹¹ ( ^cm² ml _O₂ )/(s ml mmHg). A semi-logarithmic relationship has been shown between the hydrogel water content and oxygen permeability (in Valor units). The International Organization for Standardization (ISO) specifies permeability using the SI unit hectopascal (hPa) for pressure. Thus, Dk = ^10⁻¹¹ ( ^cm² ml _O₂ )/(s ml hPa). Valor units can be converted to hPa units by multiplying them by the constant 0.75.

In this specification, "biodegradable," including its grammatical variations, means that a material can be broken down by biological action (e.g., by microorganisms) into particularly harmless products.

In this specification, “recyclable,” including its grammatical variations, means material that is processable or can be processed (from used and/or waste) to produce a material suitable for reuse.

In this specification, “Gurley second” or “Gurley number” is a unit representing 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 (0.176 psi) of water (ISO 5636-5:2003) (porosity). Furthermore, in the case of stiffness, the “Gurley number” is a unit of measurement for the force required to deflect a vertically held material by a given amount (1 milligram force), and is a unit of measurement for a piece of said material. Such values can be measured with a device from Gurley Precision Instruments (Troy, New York).

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

Griffin's method for nonionic surfactants, described in 1954,
HLB=20 ^* _Mh /M
[In the formula, _Mh is the molecular weight of the hydrophilic portion of the molecule, and M is the molecular weight of the entire molecule.] This functions as shown, and the results are shown on a scale from 0 to 20. An HLB value of 0 corresponds to a completely lipophilic/hydrophobic molecule, and a value of 20 corresponds to a completely hydrophilic/oleophobic molecule.

HLB values can be used to predict the surfactant properties of molecules.
Less than 10: Lipid-soluble (water-insoluble)
Greater than 10: Water-soluble (lipid-insoluble)
1.5-3: Antifoaming agent; 3-6: W/O (water in oil) emulsifier; 7-9: Wetting and spreading agent; 13-15: Cleaning agent; 12-16: O/W (oil in water) emulsifier; 15-18: Solubilizer or hydrotrope.

In some embodiments, the HLB value of the SFAE/glyceride/FAS blend (or the entire formulation containing the blend) as described herein may be in a lower range. In some embodiments, the HLB value of the SFAE/glyceride/FAS blend (or the entire formulation containing the blend) as described herein may be in a moderate to high range.

In this specification, “SEFOSE®” refers to a sucrose fatty acid ester (soyate) prepared from soybean oil containing one or more unsaturated fatty acids, which is commercially available from Proctor & Gamble Chemicals (Cincinnati, OH) under the trade name SEFOSE 1618U (see Sucrose Polysoyate below). SEFOSE® is an exemplary SFAE for use in the methods and barrier formulations of this disclosure.

In this specification, "soyate" means a mixture of fatty acid salts derived from soybean oil. The methods and SFAEs for use in barrier formulations described herein may contain or be derived from "soyate."

In this specification, "oilseed fatty acids" means fatty acids from plants including, but not limited to, soybeans, peanuts, rapeseed, barley, canola, sesame seeds, cotton seeds, palm kernels, grape seeds, olives, safflower, sunflower, copra, corn, coconut, flaxseed, hazelnuts, wheat, rice, potatoes, cassava, legumes, camelina seeds, mustard seeds, and combinations thereof. The fatty acid chains of SFAE/glycerides/FAS blends may be oilseed fatty acids.

In this specification, “wet strength” refers to a measure of how well a web of fibers holding together paper (or other three-dimensional solid cellulose-based products) can resist breaking forces when the paper is wet. Wet strength can be measured using the Finch Wet Strength Device from Thwing-Albert Instrument Company (West Berlin, NJ). In this case, wet strength is typically provided by wet strength additives such as kimene, cationic glyoxylated resins, polyamidoamine-epichlorohydrin resins, and polyamine-epichlorohydrin resins, including epoxide resins. In embodiments, cellulose-based materials coated with barrier formulations as described herein exhibit such wet strength in the absence of such additives.

In this specification, "wet" means being covered or saturated with water or another liquid.

The methods described herein may include a further step of exposing the contacted cellulose-based material to heat, radiation, a catalyst, or a combination thereof for a sufficient time to bond the SGF blend, CNF, and/or reinforced CNF to the cellulose-based material. In relevant embodiments, such radiation may include, but is not limited to, UV, IR, visible light, or a combination thereof. In another relevant embodiment, 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.

In this specification, "natural wax" refers to a material with a relatively high molecular weight/high melting point. Examples of "natural wax" include biowaxes obtained from renewable resources such as vegetable oils, fatty acids, and fatty acid esters (e.g., https://www.researchgate.net/publication/318385619_High_Quality_Biowaxes_from_Fatty_Acids_and_Fatty_Esters_Catalist_and_ See Reaction_Mechanism_for_Accompanying_Reactions and https://www.researchgate.net/figure/a-Preparation-of-canola-PFFA-18-biowax-b-Preparation-of-nanocellulose-from-canola_fig1_306527797.

In this specification, "cellulose crosslinking agent" means known cellulose crosslinking agents, such as glyoxal and low-reactivity dialdehydes or anhydrides.

In this specification, "glyceride" has its general meaning and refers to acylglycerols, which are esters 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 mono, di, and triglycerides. Because these structures can contain different carbon numbers, different degrees of unsaturation, and different stereochemistrys and positions of olefins, their aliphatic chains can vary.

Glycerides are obtained by esterification with substantially pure fatty acids using known esterification processes. Glycerides can also be extracted from vegetable oils and animal fats by known extraction methods.

In this specification, "fatty acid" has its general meaning and refers to a carboxylic acid having an aliphatic chain that may be saturated or unsaturated. In this specification, "fatty acid" may refer to a fatty acid group bonded to a glycerol residue of a glyceride.

The fatty acid group of the glyceride can be any known fatty acid. In preferred embodiments, the fatty acid is known to be present in food, is edible, and/or approved by the FDA. In some embodiments, the fatty acid is obtained from oilseeds. In other embodiments, the fatty acid is obtained from other sources of natural edible fats and oils.

The fatty acids in a glyceride 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 a triglyceride may contain three different fatty acid groups attached to a glycerol residue.

Exemplary saturated fatty acids for use in the formulations/compositions of this disclosure may be selected from butyric acid (butanoic acid), caproic acid (hexanoic acid), caprylic acid (octanoic acid), capric acid (decanoic acid), lauric acid (dodecanoic acid), myristic acid (tetradecanoic acid), palmitic acid (hexadecanoic acid), stearic acid (octadecanoic acid), arachidic acid (eicosanoic acid), behenic acid (docosanoic acid), or lignoceric acid (tetracosanoic acid).

Exemplary monounsaturated fatty acids for use in the formulations/compositions of this disclosure may be selected from caproleic acid (deca-9-enoic acid), lauroleic acid ((Z)-dodeca-9-enoic acid), myristoleic acid ((Z)-tetradeca-9-enoic acid), palmitoleic acid ((Z)-hexadeca-9-enoic acid), oleic acid ((Z)-octadeca-9-enoic acid), elaidic acid ((E)-octadeca-9-enoic acid), vaccenic acid ((E)-octadeca-11-enoic acid), gadoleic acid ((Z)-icosa-9-enoic acid), erucic acid ((Z)-docosa-13-enoic acid), brassic acid ((E)-docosa-13-enoic acid), or nervonic acid ((Z)-tetracosa-15-enoic acid).

Exemplary polyunsaturated fatty acids for use in the formulations/compositions of this disclosure include linoleic acid (LA) ((9Z,12Z)-octadeca-9,12-dienoic acid), alpha-linolenic acid (ALA) ((9Z,12Z,15Z)-octadeca-9,12,15-trienoic acid), γ-linolenic acid (GLA) ((6Z,9Z,12Z)-octadeca-6,9,12-trienoic acid), columbic acid ((5E,9E,12E)-octadeca-5,9,12-trienoic acid), stearidonic acid ((6Z,9Z,12Z,15Z)-octadeca-6,9,12,15-tetraenoic acid), meadic acid ((5Z,8Z,11Z)-icosa-5,8,11-trienoic acid), and dihomo-γ -Linolenic acid (DGLA) ((8Z,11Z,14Z)-Eicosa-8,11,14-Trienoic acid), Arachidonic acid ((5Z,8Z,11Z,14Z)-Eicosa-5,8,11,14-Tetraenoic acid), Eicosapentaenoic acid (EPA) ((5Z,8Z,11Z,14Z,17Z)-Eicosa-5,8,11,14,17-Peco-Linolenic acid (DGLA) ((8Z,11Z,14Z)-Eicosa-8,11,14,17-Trienoic acid), Eicosapentaenoic acid (EPA) ((5Z,8Z,11Z,14Z,17Z)-Eicosa-5,8,11,14,17-Peco-Linolenic acid (DGLA) ((8Z,11Z,14Z)-Eicosa-8,11,14-Trienoic acid), Arachidonic acid ((5Z,8Z,11Z,14Z)-Eicosa-5,8,11,14-Tetraenoic acid), Eicosapentaenoic acid (EPA) ((5Z,8Z,11Z,14Z)-Eicosa-5,8,11,14-Peco-Linolenic acid (DGLA) ((8Z,11Z,14Z)-Eicosa-8,11,14-Trienoic acid), Arachidonic acid ((5Z,8Z,11Z,14Z)-Eicosa-5,8,11,14-Tetraenoic acid), Eicosapentaenoic acid (EPA) ((5Z,8Z,11Z,14Z)-Eicosa-5,8,11,17-Peco-Linolenic acid (DGLA) (( The following can be selected: docosapentaenoic acid (DPA) ((7Z,10Z,13Z,16Z,19Z)-docosa-7,10,13,16,19-pentaenoic acid), and docosahexaenoic acid (DHA) ((4Z,7Z,10Z,13Z,16Z,19Z)-docosa-4,7,10,13,16,19-hexaenoic acid).

In some embodiments, one or more glycerides may comprise a blend of one or more monoglycerides, one or more diglycerides, and/or one or more triglycerides. In this regard, mono, di, and triglycerides can be blended in any weight ratio. That is, any one of the mono, di, or triglycerides may be the primary glyceride component of the formulation by weight (i.e., more than 50% by weight when the total weight of glycerides is considered to be 100% by weight). In another embodiment, the formulation may contain no monoglycerides, no diglycerides, and no triglycerides.

One or more glycerides may differ in their fatty acid alkyl groups. For example, one or more glycerides may contain fatty acid groups with different carbon numbers, different degrees of unsaturation, and/or different stereochemistrys and positions of olefins. Multiple glycerides may include tripalmitine and/or tristearin.

In some embodiments, the glyceride may be a combination of one or more water-insoluble glycerides (for example, triglycerides, as described above, are typically strongly nonpolar and hydrophobic) and one or more water-soluble glycerides (any weight ratio between 0.1:99.9 and 99.9:0.1), or it may be an insoluble glyceride alone or solely an insoluble glyceride. The solubility of the glyceride can be determined, for example, by its HLB value.

Those skilled in the art will understand that the HLB values of one or more glycerides can be selected by varying one or more of the glyceride parameters described above. In this regard, when multiple glycerides are used, each glyceride may be selected to have similar or different HLB values (for example, a lower range may be used in combination with a higher range).

In this specification, “fatty acid salt” (or “FAS”) has its general meaning and refers to any one or more salts of fatty acids previously disclosed herein. Exemplary cations of fatty acid salts include, but are not limited to, salts of calcium, potassium, and sodium. Fatty acid salts can be synthesized by known methods or extracted from vegetable oils or animal fats by known methods. One exemplary method involves adding sodium hydroxide to fatty acids found in animal fats or vegetable oils (such as those derived from oilseeds). For example, sodium palmitate can be obtained from palm oil.

One or more fatty acid salts may contain one or more calcium, potassium, or sodium salts. The calcium, potassium, or sodium salts of fatty acids are obtained from naturally occurring sources such as oilseeds. One or more fatty acid salts may contain 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 both one or more glycerides and one or more fatty acid groups, the weight ratio of glycerides to fatty acid salts may be about 0.1:99.9 to about 99:0.1, about 10:90 to about 90:10, about 20:80 to about 80:20, about 35:65 to about 65:35, about 40:60 to about 60:40, about 45:55 to about 55:45, or about 50:50.

The weight ratio of SFAE in the SGF blend can be 0:100 to 100:0 or any weight ratio in between (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 the SGF blend can be 0:100 to 100:0 or any weight ratio in between (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 the SGF blend can be 0:100 to 100:0 or any weight ratio between these (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 the SGF blend can be 0:100 to 100:0 or any weight ratio in between (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 the cellulose crosslinking agent in the SGF blend can be 0:100 to 100:0 or any weight ratio between these (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 selection of the blend, the bonding of SGF blends alone is sufficient to make the contacted substrate hydrophobic; that is, hydrophobicity is achieved without the addition of waxes, rosins, resins, diketenes, shellac, vinyl acetate, PLA, PEI, oils, other water-repellent chemicals, or combinations thereof (i.e., secondary hydrophobic substances). This includes, among other things, that other properties such as strengthening, rigidification, and bulking of cellulose-based materials are achieved by the bonding of glyceride/fatty acid salts alone.

The use of CNF alone as a binder has also been shown to increase the hydrophobicity of the substrate it comes into contact with.

Saturated SFAEs, glycerides, and fatty acid salts are typically solid at the nominal processing temperature, while unsaturated SFAEs, glycerides, and fatty acid salts are typically liquid. This allows for the formation of a uniform and stable dispersion of saturated glycerides and fatty acid salts in aqueous coatings without significant interaction or incompatibility with other coating components, which are typically hydrophilic. Furthermore, this dispersion allows for the preparation of high concentrations of saturated glycerides and fatty acid salts without adversely affecting the rheology, uniform coating application, or performance characteristics of the coating. If the saturated glyceride and fatty acid salt particles melt and adhere after heating, drying, and solidification of the coating layer, the coating surface becomes hydrophobic. The natural waxes of this disclosure are also solid at the nominal processing temperature.

All sugar fatty acid esters, including monosaccharides, disaccharides, and trisaccharides, are adaptable to uses relating to aspects of this disclosure. Sugar fatty acid esters may be mono, di, tri, tetra, penta, hexa, hepta, or octa esters, and combinations thereof, including the fatty acid portion being saturated, unsaturated, or a combination thereof.

SFAEs may contain, or are essentially composed of, sucrose esters of fatty acids.

Many methods are publicly known and available for producing or otherwise providing the SFAEs of this disclosure, and all such methods are considered to be available for use within the broad scope of this disclosure. For example, in certain embodiments, the fatty acid esters are preferably synthesized by esterifying sugars with one or more fatty acid moieties obtained from oilseeds including, but not limited to, soybean oil, sunflower oil, olive oil, canola oil, peanut oil, and mixtures thereof.

SFAE may include a sugar moiety containing, but not limited to, a sucrose moiety in which one or more of its hydroxyl hydrogens are substituted by an ester moiety. In relevant embodiments, disaccharide esters for use in this disclosure may have structures of formula I published in '073, all of which are by reference to this specification.

Suitable disaccharides for SFAE also include xylose, glucose, raffinose, maltodextrose, galactose, glucose combinations, fructose combinations, maltose, lactose, mannose combinations, erythrose combinations, isomaltose, isomaltulose, trehalose, trehalulose, cellobiose, laminaribiose, chitobiose, and combinations thereof.

In another embodiment, starch fatty acid esters may be used, where the starch may be derived from any suitable source such as dent corn starch, waxy 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 of this disclosure, the SFAE compound may have a high degree of substitution. In some embodiments, the sugar fatty acid ester is a sucrose polysoyate.

SFAEs can be produced by the methods disclosed in the '073 application. For example, sugar fatty acid esters can be produced by esterification with substantially pure fatty acids by known esterification processes. They can also be prepared by transesterification using sugars and fatty acid esters in the form of fatty acid glycerides derived from, for example, natural sources, such as oils extracted from oilseeds, such as those found in soybean oil. Transesterification reactions that provide sucrose fatty acid esters using fatty acid glycerides are described, for example, in U.S. Patents 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.

Cellulose-based products produced by the methods described herein may be configured to exhibit higher hydrophobicity (or water resistance) compared to similar untreated cellulose-containing materials. In relevant embodiments, treated cellulose-containing materials exhibit higher oleophobicity (or OGR) compared to similar untreated cellulose-containing materials. In further relevant embodiments, treated cellulose-containing materials may be biodegradable, compostable, and/or recyclable. In one embodiment, treated cellulose-containing materials are both hydrophobic (water resistance) and oleophobic (lipid resistance) (OGR).

The cellulose-based products of this disclosure may have improved mechanical properties compared to untreated similar materials. For example, paper bags treated by the methods described herein show increases in burst strength, Gurley number, tensile strength, and/or maximum load energy. In one embodiment, the burst strength is increased 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 embodiment, the Gurley number is increased 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 embodiment, the tensile strain is increased 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. In another embodiment, the maximum load energy increases by approximately 1.0–1.1 times, approximately 1.1–1.2 times, approximately 1.2–1.3 times, and approximately 1.3–1.4 times.

Cellulose-containing materials may be base papers containing microfibrillated cellulose (MFC) or cellulose nanofiber (CNF), as described, for example, in U.S. Publication No. 2015/0167243 (which in whole is incorporated herein by reference), where the MFC or CNF is added during the forming and papermaking processes, and/or added to the previous molded layer as a coating or secondary layer to reduce the porosity of the base paper. In embodiments, the resulting contacted base paper is adjustable in water resistance and lipid resistance. In relevant embodiments, the resulting base paper may exhibit a Gurley value of at least about 10 to 15 (i.e., Gurley air resistance (sec/100cc, 20oz.cyl.)), or at least about 100, at least about 200 to about 350. In one embodiment, the barrier coating described herein may be a laminate for one or more layers, or may provide one or more layers as a laminate, or may reduce the amount of coating of one or more layers, in order to achieve similar performance effects (e.g., water resistance, grease resistance, etc.). In related embodiments, the laminate may include a biodegradable and/or composable heat seal or adhesive.

In one embodiment, the SGF blend may be combined with one or more coating components for internal and surface sizing (alone or in combination) including, but not limited to, pigments (e.g., clay, calcium carbonate, titanium dioxide, plastic pigments), binders (e.g., starch, soy protein, polymer emulsion, PvOH, casein), and additives (e.g., glyoxal, glyoxalized resins, zirconium salts, polyethylene emulsion, carboxymethylcellulose, acrylic polymer, alginate, polyacrylate gum, polyacrylate, bactericide, oily defoamer, silicone-based defoamer, stilbene, direct dyes, and acid dyes). In relevant embodiments, such components can provide one or more properties, including but not limited to: construction of fine porous structures, formation of light scattering surfaces, improved ink receptivity, improved gloss, bonding of pigment particles, bonding of coatings to paper, reinforcement of base sheets, filling of pores in pigment structures, reduced water sensitivity, resistance to wet picking in offset printing, prevention of blade scratching, improved gloss in supercalendering, reduced dusting, adjustment of coating viscosity, provision of water retention, pigment dispersion, maintenance of coating dispersion, prevention of coating/coating color deterioration, control of foaming, reduction of trapped air and coating craters, increased whiteness and brightness, and control of color and hue. It will be apparent to those skilled in the art that the combination may vary depending on the desired properties of the final product.

In wet-end coating, the SGF blend can 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 relevant embodiments, SGF can be present in amounts 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), approximately 4.0% (wt/wt) to approximately 5.0% (wt/wt), approximately 5.0% (wt/wt) to approximately 10% (wt/wt), or approximately 10% (wt/wt) to approximately 50% (wt/wt) of the total fibers present.

In wet-end coating, CNF can 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 embodiments, the CNF may be present in 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), and about 4.0% (wt/wt) to about 5.0% (wt/wt) of the total fibers present. It can exist at approximately 5.0% (wt/wt) to 10% (wt/wt), approximately 10% (wt/wt) to 20% (wt/wt), approximately 20% (wt/wt) to 30% (wt/wt), approximately 30% (wt/wt) to 40% (wt/wt), approximately 40% (wt/wt) to 50% (wt/wt), approximately 60% (wt/wt) to 70% (wt/wt), approximately 70% (wt/wt) to 80% (wt/wt), or approximately 80% (wt/wt) to 90% (wt/wt).

In wet-end coating, reinforced CNF can 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 embodiments, the reinforced CNF may be present in 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), and about 4.0% (wt/wt) to about 5.0% (wt/wt) of the total fibers present. t) can exist in concentrations of approximately 5.0% (wt/wt) to 10% (wt/wt), approximately 10% (wt/wt) to 20% (wt/wt), approximately 20% (wt/wt) to 30% (wt/wt), approximately 30% (wt/wt) to 40% (wt/wt), approximately 40% (wt/wt) to 50% (wt/wt), approximately 60% (wt/wt) to 70% (wt/wt), approximately 70% (wt/wt) to 80% (wt/wt), or approximately 80% (wt/wt) to 90% (wt/wt).

In this specification, "coating weight" refers to the weight (wet or dry) of the material to be applied to the substrate. This is expressed in pounds per strip or grams per square meter.

In coating applications, the reinforced CNF can be present on the surface of the substrate in a coating weight of at least about 0.05 g/ ^m² . In related embodiments, the SGF blend can be present on the surface of the cellulose-based material in 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 applications, the SGF blend can be present on the surface of the substrate in a coating weight of at least about 0.05 g/ ^m² . In related embodiments, the SGF blend can be present on the surface of a cellulose-based material in 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 applications, CNF can be present on the surface of the cellulose-based material (or substrate) in a coating weight of at least about 0.05 g/ ^m² (gsm). In related embodiments, CNF can be present on the surface of the cellulose-based material in 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 .

Hydrophobic barrier properties can be imparted to the substrate by SGF blends and/or reinforced CNF in the absence of secondary hydrophobic materials.

The barrier formulation may contain one or more emulsifiers or emulsifying agents in concentrations sufficient to form an emulsion with the SGF blend and/or with the enhanced CNF and water. Suitable emulsifiers or emulsifying agents include buffers, polyvinyl alcohol (PvOH), carboxymethylcellulose (CMC), milk proteins, gelatin, starch, acetylated polysaccharides, alginates, carrageenan, chitosan, inulin, long-chain fatty acids, waxes, agar, glycerol, gum, lecithin, poloxamer, monoglycerol, diglycerol, monosodium phosphate, monostearate, propylene glycol, detergents, cetyl alcohol, glycerol esters, (saturated) ((poly)unsaturated) fatty acid methyl esters, and combinations thereof.

The methods described herein may include a step of predetermining the content of the SGF blend to be included in the reinforced CNF and/or the components of the SGF blend. In some embodiments, this predetermining step can be performed before preparing the reinforced CNF. The predetermining step can be performed to achieve a desired effect. When the reinforced CNF is used in a barrier formulation and/or added to the finished paper stock at the wet end, the predetermining step can be performed to achieve a desired level of water resistance and/or a desired level of oil and grease resistance. In some embodiments, the predetermining step can be performed to increase the dewatering rate of the finished paper stock or fiber slurry. Increasing the dewatering rate improves the production rate of cellulose-based articles, for example. As described above, dewatering of slurries containing CNF is one of the biggest problems directed toward the use of CNF. An increased dewatering rate applies to both the preparation of reinforced CNF binders and the use of reinforced CNF binders in barrier formulations, for example. Dehydration is well known in the paper industry and is also described in Smook, which is entirely part of this specification by reference elsewhere in this disclosure.

The methods described herein may include the step of predetermining the content of the SGF blend to be included in the barrier formulation and/or the components of the SGF blend. In some embodiments, this predetermining step can be performed before preparing the barrier formulation or before contacting the cellulose-based material with the formulation. The predetermining step can be performed to achieve a desired effect. The predetermining step can be performed to achieve a desired level of water resistance and/or a desired level of oil and grease resistance.

As described above, barrier formulations may contain one or more pigments commonly used in the papermaking industry. One or more pigments can be present in the formulation at concentrations ranging from about 0.1% to about 90% by weight, based on the total weight of the formulation. In another embodiment, the pigment concentration may be in a range of about 1% to 10% by weight, about 11% to 20% by weight, about 21% to 30% by weight, about 31% to 40% by weight, about 41% to 50% by weight, 51% to 60% by weight, 61% to 70% by weight, 71% to 80% by weight, 81% to 90% by weight, or any other optional range between 0.1% to 90% by weight. The use of pigments is well known in the papermaking industry, and pigment concentrations can be selected to alter the properties of the final product. Examples of similar 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 formulation may contain one or more charged polymers to assist in the retention of the reinforced CNF and/or SGF blend on the 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 a cationic polymer with a relatively low molecular weight and an anionic polymer with a relatively high molecular weight.

The charged polymer may consist of one or more cationic polymers. One or more cationic polymers may include polyacrylamide. The polyacrylamide may include poly-DADMAC (polydiallyldimethylammonium chloride).

Cationic polymers may have a weight-average molecular weight of 500,000 to 10,000,000. In some embodiments, 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 10,0000. In some embodiments, a blend of charged polymers is used to achieve a “bimodal” type of weight-average MW using combinations of charged polymers having an optional MW within the aforementioned range (e.g., using a first charged polymer having a weight-average MW of less than 1,000,000 in combination with a second charged polymer having a weight-average MW of greater than 2,000,000; the weight ratio of the first charged polymer to the second charged polymer is 10:90 to 90:10). In some embodiments, the concentration of the cationic polymer in the formulation is about 0.01% to about 5% by weight, about 0.01% to about 3% by weight, 0.05% to about 0.1% by weight, or about 0.1% to about 1% by weight, or about 1% to about 3% by weight, when the total weight of the formulation is considered to be 100%. In some embodiments, the weight ratio of the cationic polymer to the reinforced CNF in the formulation is approximately 0.1:99.9 to approximately 20:80, 0.5:99.5 to approximately 15:85, approximately 1:99 to approximately 10:90, or approximately 2.5:97.5 to approximately 7.5:92.5. In some embodiments, the weight ratio of the cationic polymer to the SGF blend in the formulation is approximately 0.1:99.9 to approximately 20:80, 0.5:99.5 to approximately 15:85, approximately 1:99 to approximately 10:90, or approximately 2.5:97.5 to approximately 7.5:92.5.

In some embodiments, as described above, prolamin can be used as a retention aid in barrier formulations containing a reinforced CNF and/or SGF blend instead of a charged polymer.

The barrier formulation may also include one or more conventional papermaking binders. Exemplary binders include CNF, reinforced CNF according to the disclosure, starch, polymers, polymer emulsions, PvOH, prolamins, or combinations thereof. In some embodiments, the formulation may not contain any binders other than reinforced CNF.

The barrier formulation can be provided in the form of an emulsion. The emulsion can be used as a barrier formulation for the methods of this disclosure. In some embodiments, the emulsion may not contain emulsifiers other than the SGF blend. Alternatively, the emulsion may contain one or more emulsifiers in an amount of about 0.01% to about 80% by weight. The emulsion may also contain materials to stabilize the emulsion for a period of time (e.g., several weeks, several months), such as nano- or microfibrillated cellulose, gum, or thickeners. A list of exemplary emulsifiers is provided above.

A cellulose-based material or substrate that can be dried before application (e.g., at approximately 80–150°C) may be treated with the modified formulation, for example, by immersion, exposing the surface to the composition for less than one second. The substrate can then be heated to dry the surface, after which it is ready for use with the modified material. In one embodiment, according to the method described herein, the substrate can be treated by any suitable coating/sizing process typically carried out in a paper mill (see, for example, Smook, G., Surface Treatments in Handbook for Pulp & Paper Technologists, (2016), 4th Ed., Cpt. 18, pp. 293–309, TAPPI Press, Peachtree Corners, GA USA, which is all incorporated herein by reference).

In some applications, the cellulose-based material may be dried before processing, but no special material preparation is required to implement this disclosure. In one embodiment, the disclosed method can be used on any cellulose-based surface, including but not limited to films, rigid containers, fibers, pulp, and fabrics. In one embodiment, the barrier formulation may be applied by conventional sizing presses (vertical, inclined, horizontal), gate roll sizing presses, metering sizing presses, calender sizing, tube sizing, on-machine, off-machine, single-sided coaters, double-sided coaters, short dwells, simultaneous two-sided coaters, blade or rod coaters, gravure coaters, gravure printing, flexographic printing, inkjet printing, laser printing, water containers on calenders, and combinations thereof.

Depending on the source, the cellulose processed in the method herein may be paper, cardboard, pulp, softwood fibers, hardwood fibers, or combinations thereof, nanocellulose, cellulose nanofibers, whiskers or microfibrils, microfibrillated cotton or cotton blends, cellulose nanocrystals, or nanofibrillated cellulose.

Furthermore, modified fiber and cellulose-based materials as described herein can be repulped. Moreover, for example, water cannot be easily "pressed" into the sheet across a low surface energy barrier.

In one embodiment, the amount of barrier compound applied is sufficient to completely cover at least one surface of the substrate, for example, at least one surface of a cellulose-containing material. For example, in one embodiment, the barrier compound may be applied to the entire outer surface of a container, the entire inner surface of a container, or a combination thereof, or to one or both sides of a base paper. In another embodiment, the entire upper surface of a film may be covered by the barrier compound, the entire lower surface of a film may be covered by the barrier compound, or a combination thereof. In some embodiments, the lumen of a device/equipment may be covered by the barrier compound, the outer surface of the device/equipment may be covered by the barrier compound, or a combination thereof.

In one embodiment, the amount of barrier formulation applied is sufficient to partially cover at least one surface of the cellulose-based material. For example, only the surface exposed to the ambient atmosphere may be covered with the barrier formulation, or only the surface not exposed to the ambient atmosphere may be covered with the barrier formulation (e.g., masking). As will be apparent to those skilled in the art, the amount of barrier formulation applied may depend on the material to be covered. In one embodiment, one surface may be coated with the barrier formulation, and the opposite surface may be coated with agents including, but not limited to, proteins, wheat gluten, gelatin, prolamin, soy protein isolate, starch, modified starch, acetylated polysaccharides, alginates, carrageenan, chitosan, inulin, long-chain fatty acids, waxes, and combinations thereof. In a related embodiment, the barrier formulation may be added to the finished pulp, and the resulting material on the web may be further coated with the barrier formulation (having a composition similar to or different from the formulation added to the wet end).

Any suitable coating process can be used to deliver any of the various barrier formulations in the course of practicing this method. In one embodiment, the coating process includes dipping, spraying, painting, printing, and any optional combination of any of these processes, either alone or in conjunction with other coating processes adapted for practicing the method of this disclosure.

The permeability of a surface to various gases, such as water vapor and gases (e.g., oxygen, nitrogen, and carbon dioxide), can also be altered by barrier formulations as the barrier function of the material increases. The standard unit for measuring permeability is the valve, and protocols for measuring these parameters are available in the public domain (see ASTM std F2476-05 for water vapor, ASTM std F2622-8 for oxygen, and https://www.ametekmocon.com/products/searchbybrand/mocon for general gas testing). MOCON permeability analyzers have been recognized as industry-leading solutions for over 50 years and form the basis of many global permeability testing standards, such as ASTM D3985 and ASTM F1249. The extensive line of MOCON analyzers represents decades of technical leadership and continuous innovation in partnerships with our customers, wholesalers, and institutions. Our MOCON transmission analyzer offers broad testing capabilities across a wide range of products and materials. In some embodiments, permeability to vapors and gases can be further reduced by adding one or more prolamins to the barrier formulation.

In one embodiment, a material treated according to the disclosed method exhibits complete biodegradability, as measured by degradation in an environment under microbial attack.

Various methods are available for defining and testing biodegradability, including the shaking flask method (ASTM E1279-89 (2008)) and the Zahn-Wellens test (OECD TG 302B).

Various methods are available for defining and testing compostability, including but not limited to ASTM D6400.

The barrier-coated products of this disclosure may have TAPPI T 559 KIT test values such as 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, and greater than 11.

The barrier-coated products of this disclosure may have HST values such as at least about 65 seconds, at least about 120 seconds, at least about 240 seconds, and at least about 480 seconds.

The surface of the barrier-coated product of this disclosure may exhibit water contact angles such as about 60 to 120 degrees, at least about 90 degrees, at least about 100 degrees, at least about 110 degrees, and at least about 120 degrees.

In some embodiments, the barrier formulations of this disclosure form a stable aqueous composition, which is defined as an aqueous composition that is substantially resistant to viscosity changes, solidification, and sedimentation for at least 8 hours when contained in a sealed container and stored at a temperature in the range of about 0 to about 60 degrees Celsius. Some embodiments of the barrier formulations are stable for at least 24 hours, and often for at least 6 months.

In some embodiments, the barrier-coated product obtained by the method of this disclosure does not contain PFAS. In some embodiments, the barrier-coated product of this disclosure does not contain PFAS in the barrier coating.

In some embodiments, the barrier-coated product obtained by the method of this disclosure is folded into a three-dimensional shape and housed in a sealed package. In these embodiments, the barrier layer may be an exposed layer (or outer layer) on the inside of the package. The package material may be any conventional material for the storage, transport, and sale of food or beverage products. In these embodiments, the sealed package may also contain food or beverage products. In these embodiments, food or beverage products may be in contact with the barrier paper layer. The seal of the sealed package may be a hermetic seal.

In some embodiments, the barrier-coated products obtained by the methods of this disclosure are compatible with conventional paper recycling programs, i.e., they do not cause adverse effects on recycling operations, such as those that occur with polyethylene, polylactic acid, or wax-coated paper.

In some embodiments, the barrier-coated products obtained by the methods of this disclosure are bio-based. In this specification, “bio-based” (or “bio-based”) means a material intentionally made from substances derived from living (or formerly living) organisms. In relevant embodiments, a material containing at least about 50% such substances is considered bio-based. In some embodiments, the barrier-coated products obtained by the methods of this disclosure may be entirely bio-based. In some embodiments, the barrier formulations of this disclosure may be entirely bio-based.

In some embodiments, barrier-coated products obtained by the methods of this disclosure are recyclable. In this specification, “recyclable,” including its grammatical variations, means a material that is processable or can be processed (from used and/or waste) to produce a material suitable for reuse.

In some embodiments, the barrier-coated products of this disclosure are biodegradable. As used herein, “biodegradable,” including its grammatical variations, means that the product is decomposed by biological action (e.g., by microorganisms) into particularly harmless products.

The embodiments of this disclosure will be described in further detail below with reference to examples, but this disclosure is not limited to these examples.

[Example 1]
Example 1 was a laboratory study on the use of CNF in molded pulp products having barrier properties.

The equipment used in Example 1 is as follows:
• Buchner funnel – large (estimated to be about 8 inches in diameter).
• Thermos bottle • Laboratory vacuum pump • Spray bottle • Stopwatch

The materials that can be used in Example 1 are as follows:
- Bleached kraft pulp slurry with 1% solid (50% SWK, 50% HWK)
• CNF slurry - 0.5% solid
- CNF slurry with 10% SE-15 ^* added, 0.5% solid
SE-9 ^** / SE30 ^*** Emulsion, 1% solid
• C-PAM (cationic polyacrylamide), solid 0.1%
- Cationic coagulant, 0.1% solid
- Capim DG crease slurry containing 1% solid pigment, IMERYS.

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

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

^*** SE-30 was obtained from EAST CHEMSOURCES LIMITED. SE-30 is marketed as a sucrose fatty acid ester. Analysis of SE-30 revealed that it contains over 80% sucrose esters with various substituents. The remainder of the product was a glyceride with a relatively small amount (less than 5% by weight) of salt.

The test procedure for Example 1 was as follows:

<Blank or Contrast>
(1) Add a sufficient amount of bleached kraft slurry to a Buchner funnel to produce a fiber pad with a basis weight of 150 gsm. Record the volume of the finished pulp to be used in future runs.
(2) After adding the slurry to the Buchner funnel, start the vacuum pump.
(3) Record the time it takes to drain the finished pulp up to the "wet line," which is the point in the draining process when the surface of the fiber slurry changes from a glossy or "wet" appearance to a dull, rough surface.
(4) Apply a vacuum to the wet sample for 10 seconds.
(5) Remove the wet mat from the Buchner funnel and place it between the two blotting papers. Press the test sample by rotating the standard hand sheet roller twice across the blotting papers.
(6) Remove the pressed sample and place it in an oven at 100°C until dry.

<Internal processing (wet end coating)>
(1) Add one or more additives to an aliquot (a volume determined during the preparation of the control sample) of the finished pulp slurry and mix. See Table 1 below.
(2) Add a sufficient amount of the blended slurry to a Buchner funnel to produce a fiber pad having a basis weight of 150 gsm.
(3) After adding the slurry to the Buchner funnel, start the vacuum pump.
(4) Record the time it takes to drain the finished paper stock down to the "wetting line".
(5) Apply a vacuum to the wet sample for 10 seconds.
(6) Remove the wet mat from the Buchner funnel and place it between the two blotting papers. Press the test sample by rotating the standard hand sheet roller twice across the blotting papers.
(7) Remove the pressed sample and place it in an oven at 100°C until dry.

<Spray treatment (coated articles)>
(1) Add a sufficient amount of bleached kraft slurry to a Buchner funnel to produce a fiber pad having a basis weight of 150 gsm.
(2) After adding the slurry to the Buchner funnel, start the vacuum pump.
(3) Record the time it takes to drain the finished paper pulp to the "wetting line".
(4) Spray a known amount of diluted suspension of the additive onto the surface of the wet mat. See Table 2 below.
(5) Apply a vacuum to the wet sample for 10 seconds.
(6) Remove the wet mat from the Buchner funnel and place it between the two blotting papers. Press the test sample by rotating the standard hand sheet roller twice across the blotting papers.
(7) Remove the pressed sample and place it in an oven at 100°C until dry.

Table 1 lists the additives, expressed in their weight percentages on a dry basis.

Table 2 lists the additives, expressed in their weight percentages on a dry basis.

Based on experimental testing of exemplary embodiments, the data in Table 3 demonstrate the improvements achieved in water resistance and/or oil and grease resistance. Water resistance was tested using a water Cobb test adapted from Tappi standard test method T441om-20, "Water Absorbency of Paper." Oil and grease resistance were tested using the 3M KIT test (Tappi standard test method T559, "Grease Resistance") and an oil Cobb test using a vegetable oil adapted from Tappi standard test method T441om-20.

While the fundamental novel features of this disclosure have been described in a manner applicable to its preferred exemplary embodiments, it should be understood that those skilled in the art can omit, substitute, and modify the forms and details of this disclosure without departing from the spirit of this disclosure. Furthermore, as will soon become apparent, numerous variations and modifications are readily conceivable to those skilled in the art. For example, any feature(s) in one or more embodiments may be applicable and combined with one or more other embodiments. It is not desirable to limit this disclosure to the exact structures and operations described herein, and all preferred variant equivalents can be made to fall within the claimed scope of this disclosure. In other words, while embodiments of this disclosure have been described with reference to examples, it should be understood that variations and modifications are encompassed within the spirit and scope of this disclosure. This invention is limited only by the following claims:

All references listed herein by reference constitute part of this specification.

Claims (17)

A method for producing a cellulose-based article,
A step of adding a reinforced cellulose nanofibril binder, comprising cellulose nanofibril (CNF) and an SGF blend bound to the CNF, to an aqueous papermaking pulp, wherein the SGF blend comprises sugar fatty acid esters (SFAEs), glycerides, and fatty acid salts.
The steps include draining water from the finished paper stock to obtain a fibrous web,
A method comprising the step of forming the fibrous web into a molded article having a three-dimensional shape. The method according to claim 1 , wherein the weight ratio of CNF to the SGF blend is 10:90 to 90:10. The aforementioned reinforced cellulose nanofibril binder,
The steps include obtaining an aqueous mixture of cellulose nanofibril (CNF),
A step of obtaining an aqueous SGF blend, wherein the aqueous SGF blend comprises sugar fatty acid esters (SFAEs), glycerides, and fatty acid salts.
The steps include: mixing the aqueous mixture of CNF with the aqueous SGF blend to bond the CNF to the SGF blend and obtain the reinforced cellulose nanofibril binder;
The method according to claim 1, comprising the step of optionally reducing the water content of the CNF mixed with the aqueous SGF blend. The aforementioned reinforced cellulose nanofibril binder,
The steps include obtaining an aqueous mixture of cellulose pulp,
A step of obtaining an aqueous SGF blend, wherein the aqueous SGF blend comprises sugar fatty acid esters (SFAEs), glycerides, and fatty acid salts.
The steps include: mixing the cellulose pulp mixture with the aqueous SGF blend to obtain a cellulose/SGF mixture;
The steps include subjecting the cellulose/SGF mixture to mechanical shear force to obtain the reinforced cellulose nanofibril binder,
The cellulose pulp is optionally subjected to a pretreatment step before obtaining the cellulose/SGF mixture and/or before subjecting the cellulose/SGF mixture to the mechanical shear force ,
The method according to claim 1, wherein the pretreatment includes lowering the pH of the aqueous mixture of cellulose pulp by adding an acid . The method according to claim 4, further comprising the step of pre-treating the cellulose pulp before obtaining the cellulose/SGF mixture and/or before subjecting the cellulose/SGF mixture to the mechanical shear force. The method according to claim 1, wherein the reinforced cellulose nanofibril binder is provided as a barrier formulation comprising the reinforced cellulose nanofibril binder and further comprising one or more pigments, one or more prolamins, one or more binders, one or more emulsifiers or emulsifying substances, or one or more charged polymers. A method for imparting barrier properties to a cellulose-based material,
A step of contacting the cellulose-based material containing cellulose fibers with an aqueous barrier formulation in order to impart the barrier properties, wherein the barrier formulation comprises a reinforced cellulose nanofibril binder comprising cellulose nanofibrils (CNF) and an SGF blend bound to the CNF, the SGF blend comprising sugar fatty acid esters (SFAEs), glycerides, and fatty acid salts, and the barrier formulation comprises about 4% to about 96% by weight of the CNF and about 4% to about 96% by weight of the SGF blend,
The step of bonding the barrier compound to the surface of the cellulose-based material to obtain a bonded cellulose-based material having the barrier properties,
A method wherein the barrier properties are one or more selected from the group consisting of water resistance, lipid resistance, and gas resistance. The method according to claim 7, wherein the contact step includes coating the surface of a cellulose-based substrate with the formulation by dipping, spraying, painting, printing, or a combination of these processes. The method according to claim 8, wherein the SGF blend is present on the surface of the substrate in an amount of at least about 0.05 g/ ^m² . The cellulose-based substrate is used in paper, cardboard, bacon board, insulating materials, papermaking pulp, food storage cartons, compost bags, food storage bags, release paper, transport bags, weed blocks/barrier fabrics or films, mulching films, flower pots, packing beads, bubble wrap, oil absorbent materials, laminates, envelopes, gift cards, credit cards, gloves, raincoats, OGR paper, shopping bags, diapers, membranes, tableware, tea bags, coffee or tea containers, containers for holding hot or cold beverages, cups, plates, bottles for storing carbonated liquids, and non-carbonated materials. The method according to claim 8, wherein the surface of an article selected from the group consisting of bottles and lids for storing acidic liquids, films for food packaging, waste disposal containers, food handling equipment, fabric fibers, water storage and transport equipment, storage and transport equipment for alcoholic or non-alcoholic beverages, outer casings or screens for electronic products, interior or exterior components of furniture, curtains, upholstery items, fabrics, films, boxes, sheets, trays, pipes, water conduits, clothing, medical devices, pharmaceutical packaging, contraceptives, camping equipment, molded cellulosic materials, and combinations thereof. The method according to claim 7, wherein the bound cellulose-based material exhibits a water contact angle of 90° or more. The method according to claim 7, wherein the bound cellulose-based material exhibits a TAPPI T 559 KIT test value of 3 to 12 in the absence of a secondary hydrophobic substance. A method for manufacturing molded products,
The process includes the steps of: providing a forming tool having a three-dimensional shape including a forming portion; bringing the forming portion into contact with a cellulose composition such that the forming portion is covered with a wet layer of pulp; and dewatering the pulp layer on the forming tool to obtain the molded article.
The cellulose composition is
Cellulose pulp, and,
A reinforced cellulose nanofibril binder comprising cellulose nanofibrils (CNF) and an SGF blend bound to the CNF, wherein the SGF blend comprises sugar fatty acid esters (SFAEs), glycerides, and fatty acid salts.
Methods that include... A method for producing a molded article according to claim 13, wherein the dehydration is performed at a temperature exceeding 100°C to achieve a dry content of at least 70% by weight. A method for producing a molded article according to claim 13, further comprising the step of coating the surface of the molded article with a barrier formulation comprising a second SGF blend containing sugar fatty acid esters (SFAEs), glycerides, and fatty acid salts by dipping, spraying, painting, printing, or any combination thereof. A molded article obtained by the method described in claim 13. The molded article according to claim 16, wherein the three-dimensional shape is selected from the group consisting of bowls, cups, plates, forks, spoons, and knives.