Oil-resistant items

Abstract

An oil-resistant article free of fluorocarbon compounds is disclosed. The oil-resistant article includes a base sheet formed from pulp fibers. The base sheet is coated on at least one side with an oil-resistant coating. The base sheet is formed without the need for highly refined fibers. The base sheet is subjected to various chemical treatments, and the oil-resistant coating is formed from specific polymers selected to form an oil-resistant article with relatively high air permeability and excellent oil resistance properties.

Description

[Technical Field]

[0001] This application claims priority to U.S. Provisional Patent Application No. 63 / 023,047, filed May 11, 2020, the contents of which are incorporated herein by reference. [Background technology]

[0002] The paper industry utilizes a variety of mechanical and chemical treatments to impart various properties to the finished paper. Resistance to penetration by oil and / or grease is a particularly desirable property for paper products used in many applications. For example, oil and grease resistance is required for packaging fatty materials, such as fatty foods. Other food containers, release liners, labels, pet food containers, etc. also require oil and grease-resistant paper.

[0003] Various chemicals have been used to impart oil resistance to paper products. For example, fluorocarbon compounds have traditionally been used as surface sizing or coating agents to impart oil penetration resistance. Fluorocarbons generally have very low surface energy and are difficult to wet with oily materials. While fluorocarbon compounds are suitable for imparting oil resistance, their use has been restricted by recent government regulations.

[0004] In addition to fluorocarbon compounds, various chemicals and polymers have been proposed. For example, silicone polymers and compounds have been used in the past to coat paper. However, silicones have various drawbacks. For example, they can transfer to adjacent surfaces.

[0005] In still other cases, thermosetting polymers are used to impart oil and chemical resistance. However, incorporating thermosetting polymers into paper can prevent the paper product from being recycled later. The presence of thermosetting polymers can significantly hinder the biodegradable properties of paper.

[0006] Traditionally, mechanical treatments used to impart some degree of oil resistance include highly refining the fibers from which the paper is made. The use of highly refined fibers reduces the air and fluid permeability of the resulting paper, which can impart some resistance to oils and grease, especially when coated with the materials mentioned above. However, the use of highly refined fibers significantly increases the cost of the product and the energy required to produce it. Summary of the Invention [Problem to be solved by the invention]

[0007] In view of the above, there is a need for paper articles, such as improved paper products, that are resistant to chemical components such as oils and greases. In particular, there is a need for grease-resistant paper products that are free of fluorocarbon components and do not require the use of highly refined fibers. [Means for solving the problem]

[0008] The present disclosure generally relates to an oil-resistant article. The oil-resistant article of the present disclosure can be made almost exclusively from recyclable materials and does not contain fluorocarbon compounds. The oil-resistant article can be made from a coated paper substrate. The paper substrate can be made from highly unrefined pulp fibers, making the product economical to manufacture. The combination of a paper layer with one or more coating materials can produce an article with excellent oil resistance that can be used for all kinds of applications, such as food wrap.

[0009] For example, in one embodiment, the present disclosure provides an oil-resistant article comprising a paper base sheet containing pulp fibers. The pulp fibers can have a degree of refinement of about 85°SR to about 50°SR (measured by the Schopper-Riegler method). In one aspect, the pulp fibers can comprise more than about 60% by weight of hardwood fibers (fibers such as broad-leaved trees). The pulp fibers can be, for example, a mixture of hardwood fibers and other fibers, such as softwood fibers (fibers such as conifers), or can be made solely from hardwood fibers. The article can have a Gurley air permeability of about 5,000 s / 100 mL to about 15,000 s / 100 mL. The base sheet can have a basis weight of about 18 gsm to about 80 gsm, for example, about 30 gsm to about 50 gsm. The base sheet can have a first surface and a second surface opposite the first surface.

[0010] According to the present disclosure, an oil-resistant coating is disposed on at least one surface (one side) of the base sheet. In one embodiment, for example, the oil-resistant coating can be applied to the first and second surfaces of the base sheet. The oil-resistant coating can include a cellulose derivative, a polyvinyl alcohol polymer, a starch, a vegetable protein-based polymer, or a mixture thereof. The oil-resistant article manufactured according to the present disclosure can be free of fluorocarbon compounds. The oil-resistant article can have a final Gurley air permeability of less than about 50,000 s / 100 mL and can have a final Gurley air permeability of more than about 3,000 s / 100 mL.

[0011] In one embodiment, the oil-resistant coating is formed from carboxymethyl cellulose. The carboxymethyl cellulose can have a viscosity of less than about 800 cPs and greater than about 5 cPs. The oil-resistant coating can be applied to the base sheet in an amount of about 0.01% to about 10% by weight of the oil-resistant article, for example, about 2% to about 8% by weight of the oil-resistant article.

[0012] The base sheet can be formulated with various additives to further improve its strength and oil resistance. For example, the base sheet can include a binder. The binder can be composed of a polymer such as carboxymethyl cellulose, starch, or a mixture thereof. In one embodiment, the article is formed from a base sheet comprising a first carboxymethyl cellulose binder and a second carboxymethyl cellulose contained in an oil-resistant coating topically applied to the base sheet. The first carboxymethyl cellulose can be different from the second carboxymethyl cellulose.

[0013] A sizing agent can also be incorporated into the base sheet. The sizing agent can be, for example, an alkyl ketene dimer. The sizing agent can be incorporated into the base sheet in an amount of about 0.5% to about 4% by weight.

[0014] The oil-resistant articles of the present disclosure can be formed without incorporating filler particles into either the base sheet or the oil-resistant coating. Alternatively, filler particles can be incorporated into the base sheet in an amount of less than about 10% by weight, such as less than 5% by weight. Furthermore, the oil-resistant articles can be silicone-free and can be produced without any acid treatment, such as that used in the production of parchment paper.

[0015] As described above, articles manufactured according to the present disclosure have excellent oil resistance. For example, an oil-resistant article of the present disclosure may have an oil resistance kit value of greater than about 3 (e.g., greater than about 4) and less than about 12 (e.g., less than about 11), such as a kit value of about 3 to about 8.

[0016] Other features and aspects of the disclosure are described in more detail below. A full and enabling disclosure of the present disclosure is more particularly set forth in a later portion of this specification, including reference to the accompanying drawings, which are described below. [Brief explanation of the drawings]

[0017] [Figure 1] FIG. 1 is a cross-sectional view of one embodiment of an oil-resistant article made in accordance with the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0018] The same reference numerals in the present specification and drawings represent the same or similar features or elements of the invention.

[0019] Those skilled in the art will appreciate that the following description of the embodiments is merely exemplary and does not limit the technical scope of the present disclosure, including other aspects thereof.

[0020] The present disclosure generally relates to oil-resistant articles suitable for use in a variety of applications. For example, the oil-resistant articles of the present disclosure can be coated papers that are well suited for use as food packaging where resistance to oil and / or grease is desired. The oil-resistant articles of the present disclosure can also be used to replace wax-coated papers in many applications. For example, the oil-resistant articles can be used to make labels, different types of food wraps, pet food containers, candy wraps, and baking sheets such as microwave oven sheets. The oil-resistant articles produced according to the present disclosure can also be used in the medical field as part of patient care wraps or as packaging materials for medical instruments and devices.

[0021] Oil-resistant articles produced in accordance with the present disclosure offer a variety of different advantages and benefits. For example, the oil-resistant articles can be produced without containing fluorocarbon compounds. For example, the oil-resistant articles can contain less than 0.05% by weight of fluorocarbon compounds, and in one embodiment, can be completely free of fluorocarbon compounds. Oil-resistant articles produced in accordance with the present disclosure can also be silicone-free and can be produced without any acid treatment, i.e., exposure to acid, such as that used in the production of parchment paper. Of particular advantage, the oil-resistant articles of the present disclosure can be produced from a paper substrate or base sheet that does not contain highly refined pulp fibers. Previously, many products used highly refined pulp fibers to improve oil resistance, which significantly increased the amount of energy required to produce the product and significantly increased costs. However, oil-resistant articles according to the present disclosure can be produced from a paper substrate that does not contain highly refined fibers and can be produced from a combination of elements that provide the desired oil-resistant properties. Furthermore, the oil-resistant articles made according to the present disclosure can have a relatively simple or sophisticated structure without including multiple layers of paper. For example, in one aspect, the oil-resistant articles of the present disclosure can include a single paper layer combined with a single-sided coating or a double-sided coating applied to at least one side of the paper substrate. In this way, the resulting product has low stiffness and is easy to handle, such as when wrapping other products.

[0022] Referring to FIG. 1 , one embodiment of an oil-resistant article made in accordance with the present disclosure is illustrated, generally designated 10. FIG. 1 shows a cross-sectional view of the oil-resistant article 10. As shown, in this embodiment, the oil-resistant article 10 includes a paper base sheet 12 formed from pulp fibers. The base sheet 12 can be, for example, a wet-laid paper layer. However, in other embodiments, the base sheet 12 can be formed by air forming, foam molding, or the like. The base sheet 12 includes a first surface and an opposing second surface. An oil-resistant coating 14 is applied to the first surface of the base sheet 12, as shown in FIG. 1 . The oil-resistant coating 14 can be applied as a separate layer or can be impregnated into the top layer of the base sheet 12. The oil-resistant coating 14 is formed from an oil-resistant polymer. Suitable polymers that can be used as a coating for the base sheet 12 include cellulose derivatives, polyvinyl alcohol polymers, starch, vegetable protein-based polymers (such as soy-derived), or mixtures thereof. As shown in Figure 1, the oil-resistant article 10 can be made from only a single paper layer or base sheet 12 combined with an oil-resistant coating 14. Alternatively, the oil-resistant article can have a second coating (not shown) applied to the opposite surface of the base sheet 12.

[0023] As mentioned above, in one embodiment, the base sheet 12 is a wet-laid pulp fiber paper layer. The base sheet 12 can be formed from an aqueous suspension of fibers. Pulp fibers that can be used include hardwood fibers (such as broadleaf fibers), softwood fibers (such as coniferous fibers), thermomechanical pulp, flax fibers, other crop fibers, and plant waste fibers. Both bleached and unbleached pulp can be used. In one embodiment, the base sheet is formed by depositing an aqueous suspension of fibers onto a porous forming surface (such as a flat wire) that allows water to drain, thereby forming the base sheet. After the paper web is formed and dried, the paper can be gathered, crimped, embossed, and / or calendered.

[0024] The base sheet is primarily formed of pulp fibers. For example, the base sheet may be composed of about 90% by weight or more, e.g., about 95% by weight or more, of pulp fibers. In one embodiment, relatively short fibers are used to form the base sheet. For example, the fibers may have an average fiber length of less than about 4 mm (e.g., less than about 3 mm, or less than about 2 mm) and generally greater than about 0.2 mm (e.g., greater than about 0.5 mm). For example, in one embodiment, the fiber preparation used to form the base sheet contains primarily short-length hardwood fibers. The hardwood fibers may be present in the fiber preparation at greater than about 60% by weight (e.g., greater than about 70%, about 80%, about 90%, or greater than about 95% by weight) (as a weight percent of the total fibers present). In one embodiment, the fiber preparation includes only hardwood fibers (100% by weight). In another embodiment, the fiber preparation contains both hardwood and softwood fibers. When softwood fibers are included, the softwood fibers can be present in an amount of about 3% to about 40% by weight (eg, about 5% to about 20% by weight).

[0025] One advantage of the present disclosure is that oil-resistant articles can be produced from base sheets without using highly refined fibers. The degree of refinement of pulp fibers is referred to as the freeness value (or freeness). Measurement of freeness value (°SR) typically measures the rate at which a dilute suspension of refined fibers drains. Freeness value is measured by the Schopper-Riegler method. Freeness values ​​used in the description herein are measured according to the standard freeness method (EN-ISO-5267-1). The pulp fibers used to construct the base sheets of the present disclosure can have a refinement of, for example, less than about 85°SR (e.g., less than about 78°SR, less than about 75°SR, or less than about 73°SR), typically greater than about 50°SR (e.g., greater than about 60°SR or greater than about 70°SR).

[0026] Incorporating fibers with the above refinement into a base sheet results in a base sheet with a relatively high porosity. Porosity or permeability can be measured using a Gurley permeability tester, such as the Model-4340, according to the Gurley test method. The test can be performed according to the standard test method ISO-5636. The Gurley test measures air permeability as a function of the time required for a specific volume of air to pass through a specific area of ​​a separator under a specific pressure. The unit is s / 100 mL (seconds per 100 mL). Therefore, a lower number indicates a more open, i.e., more porous, substrate. Base sheets produced in accordance with the present disclosure may have an inherent Gurley water permeability of less than about 5000 s / 100 mL (e.g., less than about 4000 s / 100 mL, less than about 3000 s / 100 mL, or less than about 2000 s / 100 mL), and typically greater than about 500 s / 100 mL (e.g., greater than about 1,000 s / 100 mL). As used herein, the "inherent" water permeability of a base sheet refers to the water permeability of the base sheet prior to the application of an oil-resistant coating or prior to artificially increasing the water permeability through perforation or other similar treatments.

[0027] Base sheets produced according to the present disclosure typically have a basis weight greater than about 18 gsm (e.g., greater than about 21 gsm, about 25 gsm, about 30 gsm, about 35 gsm, about 40 gsm, or about 45 gsm) and typically have a basis weight less than about 80 gsm (e.g., less than about 70 gsm, less than about 60 gsm, less than about 50 gsm, less than about 45 gsm, or less than about 40 gsm).

[0028] In one aspect, the base sheet produced in accordance with the present disclosure can be produced without filler particles. For example, the base sheet can be free of titanium oxide particles, calcium carbonate particles, magnesium oxide particles, etc. Instead, the base sheet can be made from pulp fibers alone or in combination with various chemical components.

[0029] Alternatively, filler particles may be incorporated into the base sheet. The filler particles may be titanium oxide particles, calcium carbonate particles, magnesium oxide particles, or a mixture thereof. The filler particles may be present in the base sheet in an amount of less than about 10% by weight (e.g., less than about 5% by weight, or less than about 3% by weight), and generally in an amount greater than about 0.5% by weight (e.g., greater than 2.5% by weight).

[0030] Chemical components that can be applied to and / or incorporated into the base sheet include binders, sizing agents, and / or wet strength additives. For example, in one embodiment, a binder can be incorporated into the base sheet to help enhance the integrity, oil resistance, and / or runnability of the article. The binder can be composed of any suitable polymer, such as a film-forming thermoplastic polymer. In some aspects, the binder is a natural polymer obtained directly from or derived from natural sources, such as plants. The binder can be, for example, a cellulose derivative, guar gum, pectin, starch, mixtures thereof, or the like. If the base sheet is formed through a wet-laid process, the binder can be applied to the base sheet at the wet end of the process. For example, the binder can be incorporated into the fiber preparation before it is deposited on a forming surface or before it is dried. In one aspect, a cellulose derivative binder, such as carboxymethyl cellulose, can be incorporated into the base sheet. Carboxymethyl cellulose can be blended with the pulp fibers in relatively small amounts. For example, the carboxymethyl cellulose binder can be present in the base sheet of the product in an amount less than about 2% by weight (e.g., less than about 1.5%, less than about 1%, or less than about 0.5%), or in an amount greater than about 0.05% by weight (e.g., greater than about 0.08%, or greater than about 0.1%).

[0031] In one embodiment, the binder incorporated into the base sheet is a starch, such as a cationic starch. The starch can be added to the pulp fibers alone or in combination with other binders, such as the carboxymethyl cellulose binders described above. The starch can generally be incorporated into the base sheet in an amount greater than about 0.05% by weight (e.g., greater than about 0.1%, greater than about 0.5%, greater than about 1%, greater than about 2%, or greater than about 3% by weight). The starch can also be included in the base sheet in an amount less than about 5% by weight (e.g., less than about 4% by weight). In certain embodiments, for example, cationic starch can be incorporated into the base sheet in an amount of about 3% to about 4% by weight.

[0032] In one embodiment, the base sheet comprises both a carboxymethyl cellulose binder and a starch binder, as described above.

[0033] In addition to one or more binders, a sizing agent can also be incorporated into the base sheet. The sizing agent is also applied at the wet end of the papermaking process. Applying a sizing agent to the base sheet can improve the integrity of the base sheet and increase its liquid repellency. In one embodiment, the sizing agent applied to the base sheet is an alkyl ketene dimer. The amount of sizing agent added to the base sheet can be from about 0.1% to about 2% by weight, preferably from about 0.5% to about 1.5% by weight, based on the dry weight of the base sheet.

[0034] Yet another chemical component that can be incorporated into the base sheet is a wet strength agent. The wet strength agent can reduce the likelihood of base sheet degradation when the base sheet comes into contact with liquids such as water. Typically, the wet strength agent can be selected from polyamides (e.g., epichlorohydrin resins, polyamine-epichlorohydrin resins, poly(aminoamide) epichlorohydrin resins); alkylsuccinic anhydrides; polyvinylamines; and oxidized polysaccharides. Typically, the amount of wet strength agent is 0.1% to 2% by weight, preferably 0.5% to 1.5% by weight, based on the dry weight of the base sheet.

[0035] As shown in FIG. 1 , the oil-resistant article of the present disclosure further includes, in addition to a base sheet 12, at least one oil-resistant coating applied to one side of the base sheet. The oil-resistant coating is formed from an oil-resistant polymer. In one embodiment, the oil-resistant polymer can be a film-forming polymer. Specific examples of oil-resistant polymers that can be used to form the coating include cellulose derivatives, polyvinyl alcohol polymers, starches, vegetable protein-based polymers, or mixtures thereof. Particularly advantageously, in the present disclosure, the oil-resistant coating can be formed solely from one or more oil-resistant polymers without incorporating filler particles into the coating.

[0036] In one embodiment, the oil-resistant coating is formed from a carboxymethyl cellulose polymer. Typically, the carboxymethyl cellulose may have a viscosity of about 5 cPs to about 800 cPs. In one aspect, a carboxymethyl cellulose polymer with a relatively short molecular chain can be produced to improve oil resistance. For example, a carboxymethyl cellulose polymer can be selected that has a viscosity of less than about 800 cPs (e.g., less than about 400 cPs, less than about 100 cPs, or less than about 80 cPs). The viscosity of the carboxymethyl cellulose polymer is generally greater than about 5 cPs (e.g., greater than about 15 cPs, greater than about 25 cPs, greater than about 35 cPs, greater than about 45 cPs, greater than about 55 cPs, or greater than about 60 cPs). The viscosity of the polymeric materials containing the carboxymethyl cellulose polymers described herein is measured according to the DIN-53019 test method.

[0037] In one aspect, the carboxymethyl cellulose incorporated into the oil-resistant coating can be oxidized carboxymethyl cellulose. The carboxymethyl cellulose can be used in a highly purified, cold water-soluble form.

[0038] Alternatively, the oil-resistant coating can be formed from a polyvinyl alcohol polymer. In one embodiment, the polyvinyl alcohol selected has a moderate degree of hydrolysis. For example, polyvinyl alcohol can be synthesized from polyvinyl acetate and formed into products with different molecular weights and degrees of hydrolysis. Polyvinyl alcohols well suited for use in the present disclosure typically have a degree of hydrolysis greater than about 93%, and generally less than about 97% (e.g., about 95.5% to about 96.5%). The viscosity of polyvinyl alcohol is generally less than about 50 cPs (e.g., less than about 40 cPs, or less than about 35 cPs) and can range from greater than about 10 cPs (e.g., greater than about 15 cPs, greater than about 20 cPs, or greater than about 25 cPs). The viscosity of polyvinyl alcohol can be measured according to the DIN-53019 test method.

[0039] In yet another embodiment, the oil-resistant coating can be formed from starch. Any suitable starch can be applied to one or both sides of the base sheet. In one aspect, the starch is a modified corn starch having a relatively low viscosity. For example, the starch can have a viscosity of about 20 cPs to about 80 cPs (e.g., about 30 cPs to about 55 cPs). The starch can be derived from a starch source having at least 90% amylopectin, preferably waxy corn (wax maize). Starch derivatives include tertiary aminoalkyl esters obtained by reacting starch with dialkylaminoalkyl halides under alkaline conditions.

[0040] In yet another embodiment, the oil-resistant coating can be formed from a vegetable protein-based polymer. A preferred vegetable protein is soy protein. These materials consist of approximately 25 amino acid groups and can be derived from soybeans. This protein is obtained by processing soybeans after removing the oil and hull. These raw materials can be reduced in size and extracted with an alkaline solution to isolate the original soy protein along with smaller sugars. This protein material can be hydrolyzed under high pH and reflux conditions to break it down into smaller units. This protein is amphoteric, possessing reactive sites for cations and anions. The combination of hydrophobic and charged regions allows the globular protein subunits to maintain and self-associate. When hydrolyzed under alkaline conditions, the protein unfolds and reassociates between hydrophobic and hydrophilic regions. Under hydrolysis conditions, more hydrophilic anionic groups become exposed, reducing the viscosity of the solution. Optionally, soy protein can be carboxylated to obtain a soy protein with even lower viscosity. Preferred vegetable proteins herein have specific gravities ranging from about 1.007 at 5% solids by weight (30°C) to about 1.05 at 20% solids (TAPPI TISIO 104-01 Technical Information Sheet). Bulk dry densities are higher. Preferred soy proteins herein have a dry specific gravity of about 1.38. One vegetable protein herein is hydrolyzed amphoteric soy protein. This material is hydrolyzed as a 13.5% solids solution in ammonium hydroxide solution to obtain a solution pH of about 9-10.4. The material is then acidified. A preferred hydrolyzed amphoteric soy protein has a pH of about 4.0-4.5 in a 15% slurry. The protein is then typically isolated and stored as dry flakes or powder.

[0041] The oil-resistant coating is applied to the base sheet in an amount sufficient to provide the required oil-resistant properties. Typically, the oil-resistant coating comprises more than about 0.01% by weight of the oil-resistant article (e.g., more than about 0.5% by weight, more than about 1% by weight, e.g., more than about 3% by weight, more than about 5% by weight, or more than about 6% by weight). Also typically, the oil-resistant coating is present on the base sheet in an amount less than about 10% by weight of the oil-resistant article (e.g., less than about 8% by weight, less than about 6% by weight). As noted above, the oil-resistant article may have a single oil-resistant coating on one side of the base sheet, or may have two oil-resistant coatings disposed on opposite sides of the base sheet.

[0042] The oil-resistant coating can be applied to the base sheet using any suitable method or technique. In one embodiment, for example, the oil-resistant coating can be applied to the base sheet using a size press. By using a size press, the oil-resistant article of the present disclosure can be manufactured in a single step. However, in an alternative embodiment, the oil-resistant coating can be applied after the base sheet is formed. Other methods for applying the oil-resistant coating, such as knife coating or gravure printing, can also be used.

[0043] After the oil-resistant coating is formed on the base sheet, in one embodiment, the resulting article can be optionally calendered.

[0044] The oil-resistant article of the present disclosure can maintain a high air permeability compared to conventional oil-resistant sheets while having the desired oil resistance. For example, the Gurley air permeability of the oil-resistant article can be less than about 50,000 s / 100 mL (e.g., less than about 40,000 s / 100 mL, less than about 30,000 s / 100 mL, or less than about 20,000 s / 100 mL), and generally greater than about 3,000 s / 100 mL (e.g., greater than about 5,000 s / 100 mL, or greater than about 8,000 s / 100 mL).

[0045] Articles manufactured according to the present disclosure have excellent oil resistance while having relatively high air permeability. Oil resistance can be measured, for example, using a kit oil repellency test. Oil resistance can be measured, for example, using the TAPPI Test Method T559 cm-02(2002). In the kit oil repellency test, 12 test solutions containing different mixtures of toluene, n-heptane, and castor oil are premixed.

[0046] During the test, each kit test oil is dropped onto the substrate to be tested. If a black spot appears, the oil resistance is questionable. If no spot appears, the oil resistance is rated as passing. The oil resistance is expressed as the maximum number of test solutions that pass the oil resistance test (Kit Value). The higher the number of mixed solvents, the better the oil resistance of the paper. Oil-resistant articles produced according to the present disclosure may typically have a Kit Value of 3 or more (e.g., 4 or more, 5 or more, 6 or more, 7 or more, 8 or more, 9 or more, or 10 or more). The maximum Kit Value is also typically 12 or less, e.g., 11 or less.

[0047] The above results are dramatically improved when considering that the oil-resistant articles of the present disclosure are made from recyclable materials. For example, the oil-resistant articles can be repulped. Furthermore, the present disclosure allows for the production of oil-resistant articles without using highly refined pulp fibers. Furthermore, it allows for the production of oil-resistant articles that do not contain fluorine compounds or silicone compounds.

[0048] The present disclosure will be better understood with reference to the following examples. [Example]

[0049] Oil-resistant articles were manufactured and tested for oil resistance according to the present disclosure. The oil-resistant articles had a wet-laid base sheet made from 100% hardwood fibers. The base sheet also contained a carboxymethyl cellulose binder, a cationic starch binder, and an alkyl ketene dimer size. The pulp fibers used to form the base sheet had a refinement level of less than 85°SR freeness.

[0050] The base sheet was coated with an oil-resistant coating consisting of carboxymethyl cellulose. The oil-resistant article had a basis weight of about 35 gsm and an oil resistance kit value of 6. The Gurley air permeability of the oil-resistant article was greater than 5000 s / 100 mL.

[0051] A similar product was made using a different carboxymethyl cellulose with a higher viscosity number, i.e., a higher viscosity, to form an oil-resistant coating. As a result, the product had a Kit Value of only 3.

[0052] The above-described embodiments and other modifications and variations of the present invention may be implemented by those skilled in the art without departing from the spirit and scope of the present invention as defined by the following claims. It should be understood that the elements constituting the various embodiments may be interchanged in whole or in part. Furthermore, those skilled in the art will understand that the foregoing description is merely illustrative and is not intended to limit the present invention as defined by the following claims.

Claims

1. An oil-resistant article, a paper base sheet comprising pulp fibers, the base sheet having a basis weight of 18 gsm to 80 gsm and having a first side and a second side opposite the first side; an oil-resistant coating on at least one of the first side and the second side of the base sheet, the oil-resistant coating comprising carboxymethyl cellulose; The oil-resistant article does not contain a fluorocarbon compound, and the oil-resistant article has a Gurley air permeability of less than 50,000 seconds / 100 mL and more than 3,000 seconds / 100 mL; An oil-resistant article, wherein the carboxymethyl cellulose has a viscosity of less than 800 cPs and greater than 5 cPs.

2. 2. The oil-resistant article according to claim 1, An oil-resistant article, wherein the pulp fibers contained in the base sheet have a degree of refinement such that the freeness is 85°SR to 50°SR.

3. The oil-resistant article according to claim 1 or 2, The base sheet contains at least 60% by weight of hardwood fibers.

4. The oil-resistant article according to any one of claims 1 to 3, An oil-resistant article, wherein the oil-resistant coating comprises the sodium salt of carboxymethyl cellulose, the sodium salt of carboxymethyl cellulose having a viscosity of less than 800 cPs and greater than 5 cPs.

5. The oil-resistant article according to any one of claims 1 to 4, An oil-resistant article, wherein the oil-resistant coating comprises 0.01% to 10% by weight of the oil-resistant article.

6. The oil-resistant article according to any one of claims 1 to 5, The oil-resistant article, wherein the base sheet further comprises a binder.

7. 7. The oil-resistant article according to claim 6, The oil-resistant article, wherein the binder comprises carboxymethyl cellulose, starch, or a mixture thereof.

8. 7. The oil-resistant article according to claim 6, the binder comprises a first carboxymethyl cellulose; The oil-resistant article, wherein the oil-resistant coating comprises a second carboxymethyl cellulose different from the first carboxymethyl cellulose.

9. An oil-resistant article according to any one of claims 1 to 8, The oil-resistant article, wherein the base sheet further comprises a sizing agent.

10. 10. The oil-resistant article according to claim 9, The oil-resistant article, wherein the sizing agent comprises an alkyl ketene dimer, and the alkyl ketene dimer is present in the base sheet in an amount of 0.5% to 4% by weight.

11. An oil-resistant article according to any one of claims 1 to 10, The base sheet has an inherent uncoated permeability of 1000 seconds / 100 mL to 3000 seconds / 100 mL, and is an oil-resistant article.

12. An oil-resistant article according to any one of claims 1 to 11, The oil-resistant article has an oil-resistant coating on the first side of the base sheet and an oil-resistant coating on the second side of the base sheet.

13. An oil-resistant article according to any one of claims 1 to 12, The base sheet is free of filler particles.

14. An oil-resistant article according to any one of claims 1 to 13, An oil-resistant article, wherein the oil-resistant coating does not contain filler particles.

15. An oil-resistant article according to any one of claims 1 to 14, The oil-resistant article comprises a single coating layer made only from the base sheet and a single or two or more oil-resistant coatings.

16. An oil-resistant article according to any one of claims 1 to 15, The oil-resistant article has an oil resistance having a kit value of greater than 3 and less than 12.

17. An oil-resistant article according to any one of claims 1 to 16, The oil-resistant article does not contain silicone.

18. An oil-resistant article according to any one of claims 1 to 17, An oil-resistant article, wherein the base sheet has a basis weight of 30 gsm to 50 gsm.

19. An oil-resistant article according to any one of claims 1 to 18, The oil-resistant article has a Gurley air permeability of 5000 seconds / 100 mL to 15000 seconds / 100 mL.

20. An oil-resistant article according to any one of claims 1 to 19, An oil-resistant article, wherein the pulp fibers contained in the base sheet comprise at least 95% by weight hardwood fibers.

21. An oil-resistant article according to any one of claims 1 to 20, The oil-resistant article is an oil-resistant article that has been subjected to a calendering process.

Images