Aqueous dispersion for improving barrier properties

Abstract

The present invention relates to a fibrous article treated with an aqueous polyolefin dispersion having a pH value of 7.5 - 9.4, said aqueous polyolefin dispersion comprising: a. 50 - 100% by weight of an aqueous dispersion A containing the following components: i. 41 - 98% by weight of A1, which is an ethylene / (meth)acrylic acid copolymer having a (meth)acrylic acid group content of at least 14% by weight based on the total weight of the copolymer, or a mixture of different ethylene / (meth)acrylic acid copolymers each having a (meth)acrylic acid group content of at least 14% by weight based on the total weight of the copolymer, ii. 1 - 59% by weight of A2, which is another hydrocarbon polymer containing ethylenic structural units, or a mixture of other hydrocarbon polymers containing ethylenic structural units, and iii. 0 - 35% by weight of an additive different from A1 and A2; b. 0 - 50% by weight of compound B, where compound B is a material dispersible or soluble in water and different from any component of dispersion A, where - the weight percentages of A and B are based on the solids content of the entire aqueous polyolefin dispersion, - the weight percentages of the components of dispersion A are based on the solids content of dispersion A, - the sum of the weight percentages of components i to iii of dispersion A is 100%.

Description

[0001] The present invention relates to the use of fiber preparations, products based on such fiber preparations, and aqueous dispersions.

[0002] By mechanical dispersion of polyolefins in water, so-called secondary aqueous polyolefin dispersions can be produced. These dispersions provide special properties of polyolefins when applied to various substrates, including water resistance / chemical resistance. By mechanical dispersion techniques, aqueous dispersions of polymers can be obtained. Generally, secondary polymer dispersions in a carrier liquid can be prepared by high-shear mixing the polymer in the carrier liquid at a temperature above the polymer melting temperature. According to US 2014 / 0255683, an aqueous polyolefin dispersion suitable as a coating composition can be obtained by a melt-kneading method in which special thermoplastic and acidic polyolefins are processed.

[0003] Oil resistance, water resistance, and water vapor resistance belong to barrier properties and are regarded as typical key properties of coated paper and coated paperboard (both of which generally basically contain plant fibers), which can be improved by the correct selection of coatings. Polyolefins are widely used for paper coating but are usually applied as a thermoplastic melt using extrusion coating techniques. The availability of water-based polyolefin dispersions provides an economically attractive alternative. The polyolefin dispersions can be applied to paper using conventional methods for water-based coatings, including various spraying techniques. In addition, the dispersions can be printed onto the paper web, for example, by gravure printing, roll coating, etc.

[0004] US 7,528,080 proposes treating fibers with a special aqueous polyolefin dispersion to obtain corresponding treated textile products with attractive impregnation properties.

[0005] However, the above-mentioned techniques do not provide polyolefin dispersions with satisfactory barrier properties suitable for paper applications. Therefore, the problem to be solved by the present invention is to provide an aqueous polyolefin dispersion suitable for treating paper and cartons. The treatment with the aqueous polyolefin dispersion should allow the manufacture of high-quality paper / carton products having beneficial properties related to oil resistance, water resistance, and / or water vapor resistance.

[0006] The solution to this problem is a fiber preparation treated with an aqueous polyolefin dispersion having a pH value of 7.5 - 9.4, said aqueous polyolefin dispersion comprising:

[0007] a. 50 - 100% by weight of an aqueous dispersion A containing the following components:

[0008] i. 41 - 98 wt% of A1, which is an ethylene / (meth)acrylic acid copolymer having a (meth)acrylic based groups content of at least 14 wt% based on the total weight of the copolymer, or a mixture of different ethylene / (meth)acrylic acid copolymers each having a (meth)acrylic based groups content of at least 14 wt% based on the total weight of the copolymer,

[0009] ii. 1 - 59 wt% of A2, which is another hydrocarbon polymer containing olefinic structural units, or a mixture of other hydrocarbon polymers containing olefinic structural units, and

[0010] iii. 0 - 35 wt% of additives different from A1 and A2,

[0011] b. 0 - 50 wt% of compound B, where compound B is a material dispersible or soluble in water and different from any component of dispersion A,

[0012] where

[0013] - The wt% of A and B are based on the solids content of the entire aqueous polyolefin dispersion,

[0014] - The wt% of the components of dispersion A are based on the solids content of dispersion A,

[0015] - The sum of the wt% of components i to iii of dispersion A is 100%.

[0016] By definition, hydrocarbon copolymers contain only carbon and hydrogen elements. The term "olefinic structural unit" refers to the (polymer's) structural unit produced by the polymerization of the corresponding olefin. Hydrocarbon polymers containing olefinic structural units (and their corresponding mixtures) can be provided by the corresponding homopolymers and / or copolymers.

[0017] Fiber products treated with the aqueous polyolefin dispersion provide excellent barrier properties, especially oil resistance, water resistance, and water vapor resistance. The dispersion used has high stability and excellent quality.

[0018] Aqueous polymer dispersion A

[0019] The aqueous polyolefin dispersion used according to the present invention comprises an aqueous polymer dispersion A having the following components:

[0020] i. 41 - 98 wt% of A1, which is an ethylene / (meth)acrylic acid copolymer having a (meth)acrylic based groups content of at least 14 wt% based on the total weight of the copolymer, or a mixture of different ethylene / (meth)acrylic acid copolymers each having a (meth)acrylic based groups content of at least 14 wt% based on the total weight of the copolymer,

[0021] ii. 1 - 59% by weight of A2, which is a hydrocarbon polymer containing other ethylenic structural units, or a mixture of hydrocarbon polymers containing other ethylenic structural units, and

[0022] iii. 0 - 35% by weight of additives different from A1 and A2,

[0023] wherein the weight percentages of the components of dispersion A are based on the solids content of dispersion A, and the sum of the weight percentages of components i to iii of dispersion A is 100%.

[0024] According to an advantageous embodiment of the present invention, the aqueous polyolefin dispersion used according to the present invention comprises an aqueous dispersion A having the following components:

[0025] i. 51 - 95% by weight of A1, which is an ethylene / (meth)acrylic acid copolymer having a (meth)acrylic acid group content of at least 14% by weight based on the total weight of the copolymer, or a mixture of different ethylene / (meth)acrylic acid copolymers each having a (meth)acrylic acid group content of at least 14% by weight based on the total weight of the copolymer,

[0026] ii. 5 - 49% by weight of A2, which is a hydrocarbon polymer containing other ethylenic structural units, or a mixture of hydrocarbon polymers containing other ethylenic structural units, and

[0027] iii. 0 - 35% by weight of additives different from A1 and A2,

[0028] wherein the weight percentages of the components of dispersion A are based on the solids content of dispersion A, and the sum of the weight percentages of components i to iii of dispersion A is 100%.

[0029] The ethylene / (meth)acrylic acid copolymer A1 is preferably provided by an ethylene / (meth)acrylic acid copolymer having sufficient properties related to melt processability, such as a copolymer having a melt flow index (MFI) of 2 to 3000 g / 10 min measured at 190 °C under a load of 2.16 kg. According to a specific embodiment, at least 60% by weight of A1 has a (meth)acrylic acid group content of at least 19% by weight based on the total weight of the copolymer.

[0030] The aqueous dispersion used has high dispersion stability (which can also be due to a higher amount of A1), which is beneficial for related paper / cardboard applications.

[0031] Examples of suitable commercially available polyethylene / (meth)acrylic acid copolymers that can be used in the dispersions of the present invention include Primacor TM 5980 (from SK-Chemicals), NucrelTM 925, Nucrel TM 960 (from Dow) and Escor TM 5200 (from Exxonmobil).

[0032] Other copolymers A2 containing ethylenic structural units present in polymer dispersion A can be selected according to the specific (paper) application of the aqueous dispersion used. The relevant ethylenic structural units are based on polymerized olefin monomers, typically selected from alkenes and / or polyenes.

[0033] Preferably, at least 60 wt% of A2 is provided by a copolymer containing ethylene structural units (structural units produced by the polymerization of ethylene).

[0034] According to a specific embodiment, at least 60 wt% of A2 is selected from the group consisting of:

[0035] - polyolefins having ethylene and 1-octene structural units, and

[0036] - polyolefins having ethylene and propylene structural units.

[0037] Examples of suitable commercially available other polymers A2 that can be used in dispersion A of the present invention include: Dutral CO 034 and Dutral CO 038, ethylene-propylene copolymers (28 wt% propylene), "Versalis"; Vistamaxx 6202 elastomer, having an ethylene content of 15 wt%, "Exxonmobil"; Engage 8407, an ethylenic ethylene-octene copolymer based on propylene, "Dow".

[0038] Additives that can be present in the aqueous dispersion according to the present invention include dispersants, rheological additives, adhesion promoters, tackifiers, defoamers, fillers, pigments, and any other materials known for use in polymer dispersions or polymer compositions. Examples of typical additives that can be used in the aqueous dispersion according to the present invention include stearic acid, oleic acid, and other long-chain carboxylic acids, clays, synthetic silicates, silica, waxes such as paraffin wax and polyolefin waxes, and sodium dioctyl sulfosuccinate.

[0039] Compound B is optionally present in the aqueous dispersion according to the present invention. Compound B is a material that is dispersible or soluble in water, or a mixture of materials that are dispersible or soluble in water, and compound B is different from any component of dispersion A. For example, compound B can be added to improve the recyclability of materials containing the aqueous dispersion of the present invention or materials or articles formed by evaporating the solvent from such a dispersion. Compound B can be an inorganic material or an organic material. For example, compound B can be a polymer (such as a polyether) that is dispersible or soluble in water and does not contain ethylenic structural units, or a mixture of polymers.

[0040] Thus, in a specific embodiment of the present invention, there is a compound B, and it may comprise a recycling auxiliary component. The recycling auxiliary component is typically provided by polyvinylpyrrolidone (PVP) (Mw 5000 - 200000) and / or polyethylene glycol (PEG) (Mw 1000 - 100000). According to one embodiment, based on the solids content of the entire aqueous dispersion, the aqueous polyolefin dispersion contains (as a component of B) less than 5 wt%, preferably less than 4 wt% of PEG.

[0041] Typically, the (entire) aqueous polyolefin dispersion has a solids content of 10 - 60 wt%.

[0042] Preparation of the aqueous polymer dispersion:

[0043] The method for preparing the applied aqueous polyolefin dispersion generally includes steps a. to c., where

[0044] a. In a first step, all solid components of dispersion A are intimately mixed at a temperature in the range of 50 °C to 200 °C, after which a homogenous compound of all components is obtained,

[0045] b. In the next step, the homogenous compound is mixed with water, compound B, and a neutralizing agent for adjusting the pH value at a temperature 2 to 20 °C higher than the highest melting temperature of the components mixed in the first step until an aqueous dispersion is obtained, and

[0046] c. The aqueous dispersion obtained in step b. is cooled to a temperature below the melting temperature or melting range of A1 (if the A1 component does not have a consistent melting temperature).

[0047] Typically, the mixing operation in the first step is carried out in a twin - screw extruder. Typically, the mixing operation of the homogenous compound with water, compound B (if included), and the neutralizing compound is carried out under elevated pressure.

[0048] The "premixing step" a. allows for the preparation of the aqueous dispersion without the use of (additional) emulsifiers. Due to food safety reasons and properties related to heat - sealability, it is advantageous to avoid these emulsifiers in the dispersion. The mixing operation of the homogenous compound with water, compound B, and the neutralizing compound can be carried out at a pressure higher than the vapor pressure of water at the mixing temperature.

[0049] To obtain a product with attractive barrier properties, the cooling step c. is important. Usually, the aqueous dispersion is cooled to below 50 °C, preferably below 30 °C. Advantageously, the cooling of the aqueous dispersion is carried out very rapidly (usually at least 10 °C / minute, preferably at least 50 °C / minute), which additionally improves the heat-sealing properties.

[0050] In the process for preparing an aqueous polyolefin dispersion according to the invention, at a temperature 2 to 20 °C higher than the highest melting temperature of the components mixed in the first step, the homogenized blend obtained in the first step is mixed with water, compound B (if included) and a neutralizing agent until an aqueous dispersion is obtained, wherein all the dispersed particles generally have a particle size below 60 μm, preferably below 20 μm. "A temperature 2 to 20 °C higher than the highest melting temperature of the components mixed in the first step" means a temperature 2 to 20 °C higher than the highest melting temperature of any single component mixed to obtain the homogenized blend. For example, if the homogenized blend is obtained from 3 components A1, A2 and A3 each having its own melting temperature (T MA1 、T MA2 、T MA3 ) and where T MA2 >T MA1 >T MA3 , 2 to 20 °C higher than the highest melting temperature means 2 to 20 °C higher than T MA2 .

[0051] The neutralizing agent used in the process for preparing an aqueous polyolefin dispersion according to the invention can be any aqueous alkaline solution, such as an aqueous solution of NH3. The relevant aqueous polyolefin dispersion should have a pH value of 7.5 - 9.4.

[0052] The particle size of the particles present in the aqueous polyolefin dispersion used according to the invention is generally < 60 μm. The Microtrac S3500 laser diffraction system can be used to measure this particle size using the wet dispersion module. For each measurement, 1 ml of the dispersion is added to the 1-litre dispersion unit of the wet dispersion module, where the dispersion module is filled with water having a pH in the range of 7 - 10.

[0053] The liquid content of the aqueous polyolefin dispersion according to the invention is variable and generally follows that of conventional polyolefin dispersions. Usually, water is used entirely as the dispersion liquid.

[0054] The aqueous dispersion used contains ingredients approved as indirect food additives, i.e., substances that may come into contact with food as part of packaging or processing equipment but are not intentionally added directly to food. Such ingredients are sometimes referred to as food-safe materials or materials suitable for direct food contact. In this regard, "food-safe" means that these materials comply with the standards of the EU regulation "EU 10 - 2011 for plastics intended to come into contact with food" and its amendments. In one embodiment of the present invention, all ingredients present in the aqueous polymer dispersion are food-safe materials or materials suitable for direct food contact.

[0055] Generally, the aqueous polyolefin dispersion used according to the present invention has the following properties:

[0056] - The solids content is 10 - 60 wt%,

[0057] - The viscosity is 10 - 10000 mPa*s,

[0058] - The storage stability is ≥6 months,

[0059] - The average particle size is 0.1 to 50 μm.

[0060] The method according to the present invention provides a premix of the (dry) components, which is carried out in the first step: all solid components of dispersion A, in particular components A1 and A2, are intimately mixed at a temperature of 50 °C to 200 °C, and thereafter a homogeneous blend of all components is obtained. Usually, no water is used in the premix step. The premix step seems to be the basis for generating hybrid particles containing A1 and A2. In the next step, the homogeneous blend provided in the premix step is further mixed with water, optionally with compound B and with a neutralizing agent: as a result, an aqueous polyolefin dispersion is obtained, which contains dispersed hybrid particles containing A1 and A2.

[0061] To provide experimental information on the composition of the dispersion, as an analytical method, differential scanning calorimetry (DSC) and / or infrared spectroscopy can be used in particular. According to the DSC method, the melting temperature (melting range) is measured on the one hand for the starting materials (polymers) used and on the other hand for the prepared mixture (the solid content of the dispersion). The melting range of the prepared mixture is usually much broader than that of the starting materials used.

[0062] Definitions:

[0063] In the context of this specification, the following definitions are used:

[0064] -(Meth)acrylic acid means acrylic acid and / or methacrylic acid;

[0065] - A homogeneous polymer-containing blend is a blend that shows no optical defects when cast into a film with a thickness of 1 to 2 mm.

[0066] Measurement method

[0067] The following measurement methods are used to characterize the components and the resulting products mentioned in this specification:

[0068] The melt flow index (MFI) is determined in a Zwick / Roell extrusion plastometer according to ISO 1133. The MFI is measured at 190 °C under a load of 2.16 kg. For each measurement, 6 g of the material is heated in the measuring barrel for 5 minutes before starting the measurement. The MFI is the average of three parts.

[0069] The melting temperature of the components is determined using differential scanning calorimetry according to ISO 11357. For this measurement, a Mettler Toledo DSCStar System is used. This measurement is carried out in nitrogen in the temperature range from -60 to 200 °C and at a heating rate of 10 K / min.

[0070] The solids content of the dispersion is determined in a Moisture Analyzer HC103 from Mettler-Toledo GmbH. This measurement is carried out at 130 °C for 30 minutes and then until the weight is constant.

[0071] Use Thermo Fisher Scientific HAAKE TM The viscosity of the dispersion is measured using a Thermo Fisher Scientific HAAKE rotary rheometer RV1 at 20 °C using a double cone DC60 / 2Ti L configuration combined with an MPC / DC60 geometry. This measurement is carried out at a shear rate from 0 to 120 s -1 for 120 seconds. The viscosity value at a shear rate of 114 s -1 is evaluated.

[0072] The particle size is measured using a Microtrac S3500 laser diffraction system with a wet dispersion module. For each measurement, 1 ml of the dispersion is added to a 1-liter dispersion module filled with water having a pH in the range of 7 - 10. Further settings are a cell size of 2 mm and an ultrasonic duration of 60 seconds. The specific value is the x50-value in μm, which corresponds to the average particle size.

[0073] The pH value of the undiluted dispersion is determined using a pH meter PCE-228 from PCE Instruments according to DIN ISO 8975.

[0074] The preparation of samples for different barrier tests involves multiple steps: coating the dispersion onto a substrate using a wire bar, and then drying in an oven at 120 °C for 120 seconds.

[0075] The coating weight of the coated dispersion layer is determined by the gravimetric method. For this purpose, a circular piece with a defined area is cut from the uncoated substrate using a circular cutter and weighed using an analytical balance. Then, a circular piece with the same area is cut from the coated substrate and also weighed. The weight difference is standardized and used to represent the loading amount in grams per square meter.

[0076] The water vapor permeability is detected using a C390H water vapor transmission rate test system in accordance with ISO 15106-2 and ASTM F1249 from This detection is carried out under two different conditions (23 °C and 50% rh (relative humidity), and 38 °C and 90% rh). The coated side of the substrate faces the water vapor side of the detection instrument.

[0077] The water absorption / water resistance is detected using a Cobb meter in accordance with DIN EN ISO 535 ("Paper and board - Determination of water absorption"). For this purpose, a sample is cut out and weighed using an analytical balance. Then, the sample is exposed to water in the Cobb meter for a specific period of time and then placed between two blotting papers to remove excess water from the sample surface. Then, the "wet" sample is also weighed, and this weight difference is standardized and used to represent the water absorption in grams per square meter. The time can vary between 60 seconds (Cobb 60) and 1800 seconds (Cobb 1800).

[0078] The oil / grease resistance is also detected using a Cobb meter in accordance with the test procedure of DIN EN ISO 535. A sample is cut out and weighed using an analytical balance. Then, the sample is exposed to oil in the Cobb meter for a specific period of time and then placed between two blotting papers to remove excess oil from the sample surface. Then, the "oily" sample is also weighed, and this weight difference is standardized and used to represent the oil absorption in grams per square meter.

[0079] According to a preferred embodiment, the fiber product according to the invention forms a solid product, which is preferably provided by a sheet. Generally, at least 80% by weight of the fibers are provided by cellulose fibers, so that the fiber product is provided by a paper or cardboard product. The relevant fibers can be selected from cellulose and lignocellulose and their combinations, which can be obtained from annual or perennial plants, especially from wood.

[0080] Synthetic fibers can also be used, especially thermoplastic synthetic fibers, such as those based on the following polymers: glycolic acid polymers, polyolefins, polyethylene terephthalate, polyesters, polyamides, polylactides, polyvinyl alcohol, or polybutylene succinate. Additionally, reinforcing fibers can be used, such as those selected from polymer fibers, mineral fibers, non-wood natural fibers, and glass fibers, and combinations thereof. The fibers can be biodegradable and / or recyclable.

[0081] Corresponding products made of fibers can be shipping bags and sacks, shopping bags, garbage bags, food packaging, industrial packaging, medical packaging, coverts, wrappings, and bags for replacing plastic bags.

[0082] The present invention also relates to products based on the above fiber products, wherein the operation of treating with an aqueous polyolefin dispersion is carried out by applying the aqueous polyolefin dispersion as an adhesive and / or as a coating for the fibers and then removing the water in the aqueous polyolefin dispersion.

[0083] Generally, the water in the aqueous polyolefin dispersion is removed by drying, which is preferably carried out at a temperature above 75°C. The relevant (drying) temperature should generally be high enough to allow the contained polymer to form a film. The film formation can be important in terms of barrier properties.

[0084] The products are typically provided by paper or cardboard. The operation of treating the relevant paper substrate with an aqueous polymer dispersion can be carried out by using a rubber roll / wire rod, a flexographic roll coater, or by spraying. Additionally, the present invention provides the use of the above aqueous polyolefin dispersion as an adhesive and / or as a coating composition for fiber-based substrates, preferably for paper or cardboard.

[0085] The application is preferably for improving the barrier properties related to oil resistance, water resistance, and / or water vapor resistance.

[0086] In particular, these barrier properties are important for the quality of paper packaging materials. Examples

[0087] The following procedure was used to prepare various aqueous dispersions:

[0088] - In a first step, a mixture was prepared by mixing and kneading the components in a Leistritz ZSE 18Maxx twin-screw extruder at a temperature in the range of 80 - 150°C (the temperature was selected according to the composition), where different temperature zones were created within the extruder. The pressure within the extruder was a maximum of 35 bar.

[0089] - In the next step, the extruded mixture is fed into a Büchi 2l pressure reactor equipped with a dissolver mixer operating at a speed of 100 - 1000 rpm. The dispersion is prepared at an elevated temperature in the range of 90 - 150 °C under a sometimes elevated pressure (additional pressure of 0 - 100 bar). After the formation of a homogeneous dispersion, cooling of the mixture is necessary. The cooling must be carried out as quickly as possible at the crystallization temperature of the polymer until a maximum temperature of 40 °C.

[0090] The components (parts by weight, based on solids content) and conditions used for each example are listed in Table 1 below.

[0091] Table 1

[0092]

[0093] EAA#3: A dispersible polymer which is an ethylene / acrylic acid copolymer (20 wt% acrylic acid),

[0094] POE#8: A polyolefin elastomer containing ethylene and 1-octene,

[0095] POP#11: An elastomer based on propylene with an ethylene content of 15 wt%,

[0096] EPM#82: An ethylene / propylene copolymer (28 wt% propylene),

[0097] Laponite: A synthetic layered phosphate-modified silicate with a specific surface area of 330 m 2 / g.

Claims

1. A fibrous article treated with an aqueous polyolefin dispersion having a pH value of 7.5 - 9.4, said aqueous polyolefin dispersion comprising: a. 50 - 100% by weight of an aqueous dispersion A containing the following components: i. 51 - 95% by weight of A1, which is an ethylene / (meth)acrylic acid copolymer having a (meth)acrylic acid group content of at least 14% by weight based on the total weight of the copolymer, or a mixture of different ethylene / (meth)acrylic acid copolymers each having a (meth)acrylic acid group content of at least 14% by weight based on the total weight of the copolymer, ii. 5 - 49% by weight of A2, which is another hydrocarbon polymer containing olefinic structural units, or a mixture of other hydrocarbon polymers containing olefinic structural units, and iii. 0 - 35% by weight of an additive different from A1 and A2, b. 0 - 50% by weight of compound B, where compound B is a material dispersible or soluble in water and different from any component of dispersion A, where - The weight percentages of A and B are based on the solids content of the entire aqueous polyolefin dispersion, - The weight percentages of the components of dispersion A are based on the solids content of dispersion A, - The sum of the weight percentages of components i to iii of dispersion A is 100%.

2. The fibrous article according to claim 1, wherein at least 60% by weight of A1 has a (meth)acrylic acid group content of at least 19% by weight based on the total weight of the copolymer.

3. The fibrous article according to claim 1, wherein at least 60% by weight of A2 is provided by a copolymer containing ethylene structural units.

4. The fibrous article according to claim 2, wherein at least 60% by weight of A2 is provided by a copolymer containing ethylene structural units.

5. The fibrous article according to any one of claims 1 - 4, wherein at least 60% by weight of A2 is selected from the group consisting of: A polyolefin having ethylene and 1 - octene structural units, and A polyolefin having ethylene and propylene structural units.

6. The fibrous article according to any one of claims 1 - 4, wherein based on the solids content of the entire aqueous dispersion, as a component of B, the aqueous polyolefin dispersion contains less than 5% by weight of PEG.

7. The fibrous article according to claim 6, wherein based on the solids content of the entire aqueous dispersion, as a component of B, the aqueous polyolefin dispersion contains less than 4% by weight of PEG.

8. The fibrous article according to any one of claims 1 - 4, wherein the aqueous polyolefin dispersion comprises dispersed hybrid particles containing A1 and A2.

9. The fibrous article according to any one of claims 1 - 4, wherein the aqueous polyolefin dispersion has a solids content of 10 - 60% by weight.

10. The fibrous article according to any one of claims 1 - 4, which forms a solid product.

11. The fibrous article according to claim 10, wherein the solid product is provided by a sheet.

12. The fibrous article according to any one of claims 1 - 4, wherein at least 80% by weight of the fibers are provided by cellulose fibers, whereby the fibrous article is provided by a paper product.

13. The fibrous article according to claim 12, wherein the paper product is a paperboard product.

14. A product based on a fibrous article according to any one of claims 1 - 13, wherein the operation of treating with an aqueous polyolefin dispersion is carried out by applying the aqueous polyolefin dispersion as an adhesive and / or as a coating on the fibers and then removing the water in the aqueous polyolefin dispersion.

15. The product according to claim 14, wherein the water in the aqueous polyolefin dispersion is removed by drying.

16. The product according to claim 15, wherein the drying is carried out at a temperature above 75 °C.

17. The product according to any one of claims 14 - 16, which is provided by paper.

18. The product according to any one of claims 14 - 16, which is provided by cardboard.

19. Use of an aqueous polyolefin dispersion as defined in any one of claims 1 - 13 as an adhesive and / or as a coating composition for a fibrous substrate.

20. The use according to claim 19, wherein the fibrous substrate is paper.

21. The use according to claim 19, wherein the fibrous substrate is cardboard.

22. The use according to any one of claims 19 - 21, for improving the barrier properties of a fibrous substrate related to oil resistance, water resistance and / or water vapor resistance.

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