Aqueous compositions, uses thereof, and methods for providing at least one barrier property

Abstract

The present invention relates to an aqueous composition and its use for providing at least one barrier property, such as grease barrier property, oil barrier property, and / or water barrier property, to a product containing cellulosic fibers, the composition comprising an α-(1,3→glucan) polymer and at least 0.1 wt. % of an alkyl ketene dimer, calculated on the dry solids weight of the composition.

Description

[Technical Field]

[0001] The present invention relates to an aqueous composition according to the preamble of the attached independent claim, to its use and to a method for providing at least one barrier property. [Background technology]

[0002] There is a growing trend to reduce the use of plastics as packaging materials for various goods. Natural alternatives to plastics are cellulose fiber-based products such as paper and paperboard. Paper and paperboard are essentially two-dimensional sheet products that can be folded into three-dimensional packages. It is also possible to produce three-dimensional packages by using cellulose fibers using molded fiber technology. Cellulose fiber-based packaging materials generally offer strength properties suitable for protecting the packaged goods.

[0003] However, in certain applications, packaging materials should also have barrier properties to prevent the transfer of moisture, liquids, oils, greases, and / or gases through the packaging material. The packaging material should have sufficient barrier properties to prevent interaction between the packaged goods and the surrounding environment through the packaging material. The problem is that cellulose fiber-based packaging materials do not always have the required barrier properties, especially for food packaging purposes.

[0004] The barrier properties of cellulose fiber-based materials can be improved by either internal sizing or various surface treatments. Internal sizing alone does not necessarily provide the necessary moisture, liquid, grease, and oil barrier properties. The conventional solution of laminating a plastic film to the surface of a cellulose fiber-based material is not entirely problem-free. Laminated plastic films can cause problems in recycling packaging materials, such as repulping and composting. Furthermore, film lamination techniques are not suitable for providing barrier properties to three-dimensionally molded fiber articles.

[0005] Considering the above, there is a constant need to improve the barrier properties of cellulose fiber-based packaging materials.In particular, there is a need for a composition that provides barrier properties and can be applied to both two-dimensional and three-dimensional objects.Preferably, the composition used to provide barrier properties is also bio-based, biodegradable and recyclable, so as to reduce the use of petroleum-derived ingredients, bioaccumulation and carbon footprint in the packaging industry. Summary of the Invention [Problem to be solved by the invention]

[0006] It is an object of the present invention to minimize or eliminate the drawbacks present in the prior art.

[0007] It is also an object of the present invention to provide an aqueous composition that provides at least one barrier property, preferably at least two barrier properties, to products containing cellulosic fibers, and that is easy to apply to three-dimensional articles. [Means for solving the problem]

[0008] These objects are achieved by the invention with the features set out below in the characterising parts of the independent claims. Some preferred embodiments of the invention are set out in the dependent claims. The features set out in the dependent claims can be freely combined with one another, unless expressly stated otherwise. DETAILED DESCRIPTION OF THE INVENTION

[0009] An exemplary aqueous composition according to the present invention for providing at least one barrier property, such as grease barrier property, oil barrier property, fat barrier property, water barrier property, gas barrier property, and / or mineral oil barrier property to a product comprising cellulosic fibers, comprises an α-(1,3→glucan) polymer and at least 0.1 wt. % of an alkyl ketene dimer, calculated on the dry solids weight of the composition.

[0010] A typical use of the aqueous composition of the present invention is to provide at least one barrier property, such as grease barrier property, oil barrier property, fat barrier property, water barrier property, gas barrier property, and / or mineral oil barrier property, to a product comprising cellulosic fibers by applying the aqueous composition to the surface of the product.

[0011] A typical method for providing at least one barrier property, such as grease barrier property, oil barrier property, fat barrier property, water barrier property, gas barrier property, and / or mineral oil barrier property, to a cellulosic product comprising cellulosic fibers includes: forming a cellulosic product; drying the cellulosic product; applying an aqueous composition according to the present invention to at least one surface of the product; Includes:

[0012] It has been surprisingly found that aqueous compositions containing both α-(1,3 → glucan) polymers and alkyl ketene dimers can be easily applied to the surface of products containing cellulosic fibers using conventional surface application techniques. Furthermore, compositions containing α-(1,3 → glucan) polymers and alkyl ketene dimers prepared by blending also surprisingly provide the products with good barrier properties. The resulting barrier properties may include at least one, and in some cases, preferably more, barrier properties selected from grease barrier, oil barrier, fat barrier, water barrier, gas barrier, and mineral oil barrier. Compared to other possible polysaccharide polymers, such as starch or carboxymethylcellulose, α-(1,3 → glucan) polymers provide acceptable or good barrier properties to surface-treated products. This means that the amount of bio-based and biodegradable ingredients can be increased in the production of cellulosic products, particularly cellulosic packaging materials, without significantly compromising the quality of the final product. It is expected that the recyclability of surface-treated products will be easier, allowing them to be repulped using conventional repulping techniques. At the very least, the components of the aqueous composition are susceptible to being biodegradable, thereby providing additional and / or new alternatives when considering end-of-life options for surface treatment products.

[0013] The present invention may provide a product comprising cellulosic fibers having at least two barrier properties selected from grease barrier property, oil barrier property, fat barrier property, water barrier property, gas barrier property, and mineral oil barrier property. In many cases, particularly in food contact applications, it is important that a product comprising cellulosic fibers exhibit acceptable grease barrier property, oil barrier property, and water barrier property. Until now, this has required the use of multiple different barrier compositions. The present invention now provides an aqueous composition that can be used alone to provide multiple barrier properties to a product. According to one embodiment, the aqueous composition may provide a product comprising cellulosic fibers with good or at least acceptable grease barrier property and oil barrier property combined with good or at least acceptable water barrier property.

[0014] The aqueous composition may be or form part of a coating or surface sizing composition for a cellulosic fibrous web such as paper, paperboard, or for a cellulosic product such as a molded textile product.

[0015] The aqueous composition may contain 65 to 99.9 wt. %, preferably 70 to 99 wt. %, and more preferably 75 to 95 wt. % of the α-(1,3 → glucan) polymer, calculated based on the dry solids weight of the composition. For example, the aqueous composition may contain 60 to 99.9 wt. %, preferably 65 to 90 wt. %, and more preferably 70 to 85 wt. % of the α-(1,3 → glucan) polymer, calculated based on the dry solids weight of the composition. According to one preferred embodiment, the aqueous composition may contain 60 to 93 wt. %, preferably 65 to 89 wt. %, and more preferably 70 to 87 wt. % of the α-(1,3 → glucan) polymer, calculated based on the dry solids weight of the composition. It is quite surprising that an aqueous composition can contain such a large amount of α-(1,3 → glucan) polymer while still providing adequate barrier properties to the final product. This means that the amount of non-biological components in the formed barrier layer can be minimized, thereby making the final product environmentally sustainable.

[0016] In the present context, "α-(1,3→glucan) polymer" refers to a polymer having a polysaccharide backbone comprising D-glucose units linked together by glycosidic bonds. At least 70%, preferably at least 80%, more preferably at least 90% or 95%, and in some cases 99% or 100% of the glycosidic bonds are α-1,3-linked. This means that in the polysaccharide backbone, the α-D-glucose units are linked to each other via carbons 1 and 3 on adjacent α-D-glucose rings. The form of glycosidic bonds will be readily apparent to those skilled in the art, e.g. 1 It can be determined using known methods such as 1 H NMR.

[0017] According to one embodiment of the present invention, the α-(1,3→glucan) polymer may have a degree of polymerization in the range of 55-10,000, preferably 55-5,000, more preferably 100-1,000.

[0018] The polysaccharide backbone of the α-(1,3→glucan) polymer may be linear, ie unbranched.

[0019] The polysaccharide backbone of the α-(1,3→glucan) polymer may be substituted, i.e., the α-(1,3→glucan) polymer may contain substituents substituted on the hydroxyl groups of the polysaccharide backbone. According to one embodiment of the present invention, the α-(1,3→glucan) polymer may have a degree of substitution in the range of 0.05 to 3, preferably 0.1 to 2.0, preferably 0.2 to 1.5, more preferably 0.2 to 1 or 0.2 to 0.8. The degree of substitution may be, for example, 0.3 to 0.7 or 0.3 to 0.6. The degree of substitution refers to the average number of hydroxyl groups substituted with substituents on each D-glucose unit in the polysaccharide backbone of the α-(1,3→glucan) polymer. Since there are three hydroxyl groups in each D-glucose unit, the degree of substitution is 3 or less.

[0020] According to one preferred embodiment, the α-(1,3→glucan) polymer may be a polyhydroxyalkyl α-(1,3→glucan), such as, for example, polyhydroxyethyl α-(1,3→glucan).

[0021] The aqueous coating composition may contain anionic or cationic α-(1,3→glucan) polymers. The anionic or cationic nature of the α-(1,3→glucan) polymer can positively affect its water solubility.

[0022] According to one embodiment of the invention, the α-(1,3→glucan) polymer used may be anionic, ie its structure contains anionic groups, for example carboxylic acid groups.

[0023] According to a preferred embodiment, the α-(1,3-→glucan) polymer is cationic, i.e., contains a cationic substituent. The cationic substituent may be a substituted ammonium group, preferably a quaternary ammonium group, more preferably a trialkylammonium group. The alkyl group in the trialkylammonium group may be, for example, a methyl group, a hydroxymethyl group, a hydroxyethyl group, or a hydroxypropyl group. The substituted ammonium group may be, for example, a trimethylammonium group. The cationic substituent improves the water solubility of the α-(1,3-→glucan) polymer.

[0024] According to one preferred embodiment, the α-(1,3 → glucan) polymer is water-soluble. This means that the α-(1,3 → glucan) polymer is soluble in water at 25°C and pH 7 at a concentration of 1% by weight. After dissolution, no solid particles are visually observed, and the resulting solution is completely transparent. The water-solubility provides a uniform and good coating for the resulting barrier layer formed by application of the aqueous composition.

[0025] The aqueous composition according to the present invention further comprises at least 0.1 wt.% of alkyl ketene dimer, calculated based on the dry solids weight of the composition. According to one preferred embodiment of the present invention, the composition may comprise 0.1 to 35 wt.%, preferably 1 to 30 wt.%, and more preferably 5 to 25 wt.%, of alkyl ketene dimer, calculated based on the dry solids weight of the composition. According to one preferred embodiment, the aqueous composition may comprise 7 to 40 wt.%, preferably 11 to 35 wt.%, and more preferably 13 to 30 wt.%, of alkyl ketene dimer, calculated based on the dry solids weight of the composition. The alkyl ketene dimer can improve the water barrier properties provided by the aqueous composition while maintaining the resulting grease and oil barrier properties at at least acceptable levels. Thus, the presence of alkyl ketene dimers, even when present in relatively small amounts in the aqueous composition, can improve the general barrier properties as described above and provide two or more improved barrier properties to products containing cellulosic fibers.

[0026] The alkyl ketene dimer can be a C14-C22 alkyl ketene dimer, preferably a C16-C18 alkyl ketene dimer, or a mixture thereof. The alkyl ketene dimer may be in the form of a polysaccharide-stabilized aqueous dispersion when mixed with the α-(1,3→glucan) polymer to form the aqueous composition.

[0027] The alkyl ketene dimer may have a charge density in the range of -100 μmeq / g to +600 μmeq / g at pH 3.5. According to one embodiment, the alkyl ketene dimer is cationic. The cationic alkyl ketene dimer may have a charge density in the range of +25 μmeq / g to +600 μmeq / g, preferably +50 μmeq / g to +250 μmeq / g, and more preferably +75 to +150 μmeq / g at pH 3.5. According to another embodiment, the alkyl ketene dimer may be anionic. The cationic alkyl ketene dimer may have a charge density in the range of -100 μmeq / g to <0 μmeq / g, preferably -75 μmeq / g to -0.1 μmeq / g, and more preferably -25 to -5 μmeq / g at pH 3.5.

[0028] Preferably, the alkyl ketene dimer and the α-(1,3→glucan) polymer have the same ionic character, i.e., they are both anionic or cationic. According to one preferred embodiment, both the α-(1,3→glucan) polymer and the alkyl ketene dimer are cationic. According to another preferred embodiment, both the α-(1,3→glucan) polymer and the alkyl ketene dimer are anionic. According to a further embodiment, the alkyl ketene dimer and the α-(1,3→glucan) polymer have different ionic characters.

[0029] The aqueous composition according to the present invention is prepared by mixing an α-(1,3-→ glucan) polymer and an alkyl ketene dimer. No chemical reaction is expected to occur between the α-(1,3-→ glucan) polymer and the alkyl ketene dimer. This means that the aqueous composition does not have a covalent bond between the α-(1,3-→ glucan) polymer and the alkyl ketene dimer. The aqueous composition can be easily prepared by mixing using conventional mixing equipment and still provides good barrier properties when applied to the surface of a textile containing cellulosic fibers.

[0030] In addition to the α-(1,3-→glucan) polymer and alkyl ketene dimer, the aqueous composition may contain one or more additives. The amount of additive may be 0.25 to 20 parts, preferably 0.5 to 15 parts, more preferably 1 to 10 parts, and even more preferably 2 to 5 parts, calculated based on the total amount of alkyl ketene and α-(1,3-→glucan) polymer being 100. The one or more additives may be selected from inorganic particles such as kaolin, calcium carbonate, talc, titanium dioxide, and mixtures thereof; antifoaming agents such as silica-based antifoaming agents; rheology modifiers such as acrylates, acrylic copolymers, and / or hydrophobically modified ethoxylated urethanes; wetting agents such as surfactants; other barrier-promoting polymers; and / or heat-sealable polymers such as styrene acrylate. The aqueous composition preferably does not contain an organic solvent.

[0031] According to one embodiment, the aqueous composition consists of an α-(1,3→glucan) polymer and an alkylketene dimer, and optionally inorganic particles as defined above.

[0032] The aqueous composition can be applied to the surface of a cellulosic fiber-containing product by any conventional coating and / or surface sizing method, such as rod coating, curtain coating, size press coating, or spray coating. The aqueous composition may have a solids content of 2.5 to 50 wt %, preferably 5 to 35 wt %, and more preferably 10 to 25 wt %. The aqueous composition may have a viscosity of 50 to 2000 mPas, preferably 50 to 1000 mPas, measured at 23°C and 100 rpm using a Brookfield DV-E. This means that the composition can be easily applied to the surface of a cellulosic fiber-containing product by conventional application methods, such as surface sizing, air knife coating, rod coating, bar coating, blade coating, gravure coating, roll coating, curtain coating, size press coating, or spray coating. In some embodiments, the aqueous composition may be heated before application to reduce the viscosity. The aqueous composition may be applied at an application temperature of, for example, 15 to 50°C, typically 20 to 40°C.

[0033] The aqueous composition according to the present invention is applied to the surface of a product containing cellulosic fibers. The cellulosic fibers can be virgin fibers, recycled fibers, or a mixture of virgin and recycled fibers. The cellulosic fibers can be obtained by any available pulping method, such as mechanical pulping, chemical pulping, thermomechanical pulping, or chemi-thermo-mechanical pulping. The cellulosic fibers can include, for example, any cellulosic fibers separated from wood (softwood, hardwood, or a combination thereof). The cellulosic fibers can be bleached, unbleached, or a combination thereof.

[0034] In addition to the cellulosic fibers, the product may include inorganic filler particles, such as particles of calcium carbonate, kaolin, talc, titanium dioxide, or any combination thereof.

[0035] Preferably, the aqueous composition is applied directly to the surface of the product containing cellulosic fibers, i.e., without an intermediate layer. The aqueous composition may be applied to the surface of the product before and / or after drying. This means that application can be carried out on a wet surface, for example, by spraying, and / or on a dry surface, for example, by using any conventional coating technique, such as spray coating, rod coating, or size press coating.

[0036] According to one preferred embodiment, the aqueous composition according to the present invention is applied by spraying onto the surface of a three-dimensional product comprising cellulosic fibers, such as the surface of a molded textile product. The molded textile product may be a bowl, container, tray, plate, etc. According to one embodiment, the molded product comprising cellulosic fibers may be a ready-to-eat food packaging unit, an egg container, a meat container, a cup, a drinking cap, or a food carrier product such as a tray or plate. By applying the aqueous composition by spraying, even cavities, compartments, recesses, etc. in the three-dimensional product can be effectively coated.

[0037] According to one embodiment, the aqueous composition may be applied to the surface of a first product comprising cellulose or cellulosic fibers. Then, before the applied composition dries, at least one second product is attached to the surface of the first product by using the applied aqueous composition as an adhesive between the first and second products. The resulting final product thus comprises a first layer of the first product, at least one second layer of the second product, and an intermediate adhesive layer formed by the applied aqueous composition. Optionally, additional second products are attached to further enhance the properties and characteristics of the product, with the aqueous composition being applied as an adhesive between the additional second products. The first product and the second product(s) may be in the form of a sheet or web having two parallel major surfaces, with the aqueous composition applied to at least one of the major surfaces of the first product and attached to one of the major surfaces of the second product. Alternatively, the first product and second product(s) may have three-dimensional forms that can be arranged to fit snugly together, the aqueous composition is sprayed onto the surface of the first product, and then the second product is fitted snugly onto the first product for adhesion.

[0038] The aqueous composition may be applied in an amount that provides a uniform barrier layer on the surface of the product, or in an amount that provides adequate adhesion between the first product and the second product(s). The aqueous composition may be applied in two or more layers on the surface of the product. This allows for a lower amount of aqueous composition in each layer and / or results in a barrier layer with fewer, if any, pinholes. The chemical composition of the applied layers may be the same, but the application amount, i.e., layer weight, may be different. In one embodiment, all applied layers are identical to one another. The aqueous composition may be applied in an amount of at least 1.5 g / m 2 , preferably 1.5 to 15 g / m 2 , more preferably 2 to 10 g / m 2 can be applied in a total amount of

[0039] According to one embodiment of the present invention, the aqueous composition is applied to cover a portion of the surface of the article. For example, the aqueous composition may be applied to the interior or exterior surface of the three-dimensional article, for example, by spraying.

[0040] When a product containing cellulose fibers is coated with two or more successive layers of the aqueous composition, the successive layers after the first layer can be applied with or without intermediate drying, i.e., as either wet-on-dry or wet-on-wet applications. According to one embodiment, the surface of the product is dried between the application of two or more successive layers.

[0041] The aqueous composition according to the present invention provides at least one barrier property, such as grease barrier property, oil barrier property, and / or water barrier property, to a product containing cellulosic fibers. Preferably, the aqueous composition provides at least two barrier properties simultaneously, particularly grease barrier property and water barrier property simultaneously. Surprisingly, it has been found that the aqueous composition significantly increases the oil penetration time of the product containing cellulosic fibers.

[0042] According to one preferred embodiment, application of the aqueous composition provides a product having a TAPPI 559 KIT test value of at least 4, preferably at least 8, and more preferably at least 12. The KIT test value measures the repellency of a coating to oil and grease, and is measured according to standard TAPPI method T-559.

[0043] experiment

[0044] Example 1

[0045] (2D sheet fabrication)

[0046] Fiber stocks with 0.1-0.6 wt% consistency were prepared from 100% birch light-colored kraft pulp. 0.02-0.06 wt% of alkyl ketene dimer (AKD) was added to the fiber stock and mixed under turbulent flow conditions for at least 2 minutes. Subsequently, 0.04-0.08 wt% of a synthetic retention polymer, a mixture of polydiallyldimethylammonium chloride and cationic polyacrylamide (PDACMAC+CPAM), was added. The retention polymers used had high to very high average molecular weights (MW) (at least 2,000,000 Da) and low to medium charge densities (5-20 mol% derived from cationic monomers). After adding PDADMAC+CPAM, the stock was mixed for at least 1 min, and then the fiber stock was vacuum-formed to a dryness of 20-30 wt. % (200-800 g / m2) under a vacuum of 200-650 mBar against a 10 cm flat circular forming wire with 200-400 μm openings using a dynamic drainage analyzer (Pulpeye AB, Sweden). 2 Wet sheets with a basis weight of 1000 psi are pressed between blotter papers using an L&W sheet press until a dryness of 25-55% is reached. The sheets are then heat-press dried and thermoformed to a thickness of 0.2-1.2 mm between metal plates at 130-200°C until a dryness of 94-99% is reached. The resulting final sheets had a Bendtsen roughness of 300 ml / min to 700 ml / min measured according to ISO 8791-2 and a Bendtsen air permeability of 20 ml / min to 25 ml / min measured according to ISO 5636-3.

[0047] (Preparation of aqueous composition)

[0048] Dry cationic α-(1,3→glucan) polymer (degree of polymerization 450, degree of substitution 0.3) was dissolved in deionized water to obtain a polymer solution with a dry concentration of 3.4 wt%. A commercially available cationic alkyl ketene dimer, containing 95 wt% C18-alkyl ketene dimer on a dry basis, was obtained as a 20 wt% solution. The alkyl ketene dimer solution was added to the α-(1,3→glucan) polymer solution until the resulting aqueous composition had an alkyl ketene dimer concentration of 27.6 wt%, calculated from the dry solids content of the aqueous composition. The aqueous composition containing the α-(1,3→glucan) polymer and alkyl ketene dimer was mixed until both components were visibly dispersed.

[0049] (Spray coating of two-dimensional sheets with aqueous compositions)

[0050] The two-dimensional sheets produced were weighed to 7.9 to 8.4 g / m in a dry state. 2 Each sheet was spray-coated with the prepared aqueous composition by passing it through the spray beam as many times as necessary to reach a coat weight of 1000 ppm. The coated sheets were dried in an oven at 105°C for 15 minutes. The dried sheets were conditioned at 23°C and 50% RH, and their barrier performance was measured according to ISO 535:2014 (Cobb 60), Tappi T559cm-02 (KIT), and ASTM F119-82:2015 (oil penetration time).

[0051] Reference sample R-1 was spray coated with a 20 wt% solution of cationic alkyl ketene dimer, and reference samples R-2 and R-3 were spray coated with a 3.6 wt% solution of cationic α-(1,3→glucan) polymer, both of which were used in aqueous compositions.

[0052] The results are shown in Table 1.

[0053] [Table 1]

[0054] The results in Table 1 show that the aqueous compositions according to the present invention provide coated sheets with both adequate water barrier performance (Cobb 60) and good grease and oil barrier properties.

[0055] <Example 2>

[0056] The chemicals used in Example 2 are listed in Table 2. The chemicals were either obtained as a commercially available solution (alkyl ketene dimer) and used as is, or prepared as a solution by dissolving in hot water (α-(1,3→glucan) polymer, CMC) or heating at 95°C for 30 minutes (starch).

[0057] [Table 2]

[0058] Aqueous compositions were prepared according to Table 3 by mixing the components of the compositions in a diaphragm mixer.

[0059] [Table 3]

[0060] In the coating experiment, the substrate used was 205 g / m 2 The substrates were folding boxboards. One or two coating layers were applied to the uncoated substrates using the rod coating unit of an RK K Control Coater. For single-coated samples, the coating was applied using coating rods 1 to 3. For double-coated samples, the coating layers were applied using coating rods 3 to 5. The first layer was allowed to stand at room temperature for 15 to 30 minutes before the second layer was applied. The final single / double coatings were dried for 60 seconds using an IR dryer. The aqueous composition was kept at 40°C during the coating process.

[0061] The coated sheets were allowed to acclimate for a minimum of 18 hours before measuring the coating weight.

[0062] The following barrier properties were tested using the standard methods shown in brackets:

[0063] -Water vapor, WVTR (ASTM E-96, D3985 and F1927, 23°C 50%RH) -Water, Cobb300s (ISO535) -greases and oils, ·KIT exam (TAPPI method T-559pm-96) Olive oil penetration (ASTM F119-82:2015), 50℃

[0064] Cobb300 values ​​were measured from two parallel samples and values ​​were reported as the average of the two measurements. Olive oil penetration was measured on four parallel samples and values ​​were reported as the average of the measurements.

[0065] The results of Example 2 are shown in Table 4.

[0066] From Table 4, it can be seen that Samples Comp-4 to Comp-7 coated with the aqueous compositions according to the present invention provide acceptable water barrier properties as well as better grease and oil barrier properties. The difference compared to the reference samples coated with compositions containing alkyl ketene dimer and other polysaccharides (starch / CMC) is significant.

[0067] [Table 4]

[0068] Although the present invention has been described with reference to what are currently believed to be the most practical and preferred embodiments, it is understood that the present invention is not limited to the above-described embodiments, and the present invention is also intended to encompass different modifications and equivalent technical solutions within the scope of the appended claims.

Claims

1. An aqueous composition for providing at least one barrier property, such as grease barrier, oil barrier and / or water barrier, to a product containing cellulose fibers, The composition comprises an α-(1,3-glucan) polymer and at least 0.1% by weight of an alkyl ketene dimer, calculated from the dry solid weight of the aqueous composition. Aqueous composition.

2. The aqueous composition according to claim 1, characterized in that it contains 0.1 to 40% by weight, preferably 10 to 35% by weight, and more preferably 15 to 30% by weight of alkyl ketene dimer, calculated from the dry solid weight of the aqueous composition.

3. The aqueous composition according to claim 1 or claim 2, characterized in that the α-(1,3→glucan) polymer and the alkyl ketene dimer are cationic.

4. The aqueous composition according to claim 1 or claim 2, characterized in that the α-(1,3→glucan) polymer and the alkyl ketene dimer are anionic.

5. The aqueous composition according to claim 1 or claim 2, characterized in that the α-(1,3→glucan) polymer has a degree of substitution in the range of 0.05 to 3, preferably 0.1 to 2.0, more preferably 0.2 to 1.5, and even more preferably 0.2 to 1.

6. The aqueous composition according to claim 1 or claim 2, characterized in that the α-(1,3→glucan) polymer has a degree of polymerization in the range of 55 to 10,000, preferably 55 to 5,000, and more preferably 100 to 1,000.

7. The aqueous composition according to claim 1 or claim 2, characterized in that the alkyl ketene dimer is a C14-C22 alkyl ketene dimer, preferably a C16-C18 alkyl ketene dimer, or a mixture thereof, and preferably in the form of a polysaccharide-stabilized aqueous dispersion.

8. The aqueous composition according to claim 1 or claim 2, characterized in that the alkyl ketene dimer has a charge density in the range of -100 μm / g to +600 μmeq / g at pH 3.

5.

9. The aqueous composition according to claim 1 or claim 2, characterized by having a solid content in the range of 2.5 to 50% by weight, preferably 5 to 35% by weight, more preferably 10 to 25% by weight, and / or a viscosity in the range of 50 to 2000 mPas, preferably 50 to 1000 mPas.

10. The use of the aqueous composition according to claim 1 or claim 2 for a product containing cellulose fibers, by applying the aqueous composition to the surface of the product, to provide at least one barrier property such as grease barrier property, oil barrier property and / or water barrier property.

11. The use according to claim 10, characterized in that the aqueous composition is preferably applied by spraying to the surface of the product, which is a three-dimensional product containing cellulose fibers.

12. The use according to claim 10, characterized in that the product is a molded fiber product such as a bowl, container, tray, or plate.

13. The use according to claim 10, characterized in that the aqueous composition is applied as two or more layers on the surface of the product.

14. The aqueous composition contains at least 1.5 g / m² ２ Preferably 1.5 to 15 g / m ２ More preferably 2 to 10 g / m ２ The use according to claim 10, characterized in that it is provided in total quantity.

15. A method for providing at least one barrier property, such as grease barrier property, oil barrier property and / or water barrier property, to a cellulose-based product containing cellulose fibers, To form the aforementioned cellulose-based product, The process of drying the aforementioned cellulose-based product, The aqueous composition according to claim 1 or claim 2 is applied to at least one surface of the cellulose-based product, Methods that include...