Highly beaten cellulose pulp composition comprising compressed beaten cellulose pulp

Abstract

The present invention relates to a highly beaten cellulose pulp (HRC) composition for preparing a barrier paper or film, comprising 50 to 99% by weight, relative to the total dry weight of the HRC composition, of HRC having a Shopper-Riegler (SR) freeness of >70, measured according to standard ISO 5267-1, and 1 to 50% by weight, relative to the total dry weight of the HRC composition, of a compressed beaten cellulose pulp having a Shopper-Riegler freeness (SR), measured according to standard ISO 5267-1, of <30 and a water retention value (WRV), measured according to standard ISO 23714, of >120%. The present invention further relates to an HRC paper or film, and to a multi-layer material comprising the HRC composition.

Description

[Technical field]

[0001] The present disclosure relates to highly refined cellulose pulp (HRC) compositions for preparing papers or films useful, for example, as gas and / or grease barrier papers or films in paper and cardboard. The present invention further relates to films and multi-layer materials comprising said HRC compositions and methods for making said HRC compositions. [Background technology]

[0002] Papers, films and coatings made from highly refined cellulose pulp (HRC), such as microfibrillated cellulose (MFC), have emerged as interesting alternatives to traditional gas barrier films, such as aluminum and synthetic polymer films and their various laminates. Films containing HRC have been developed in which cellulose fibrils are dispersed and / or suspended in an aqueous medium, then rearranged and rebonded together to form dense films with high barrier properties.

[0003] In addition to providing excellent gas barrier properties, the HRC or MFC papers, films and coatings may also be essentially transparent or translucent to visible light, making them particularly useful in applications requiring transparency or translucency of the HRC layer in the visible light spectrum (typically in the range of 380-740 nm).

[0004] HRC paper or film can be made by applying an HRC suspension onto a porous substrate, such as a membrane or wire, to form a web, and then draining the web through the substrate to form an HRC paper or film. This can be achieved, for example, by using a process paper machine type or a cardboard machine type. US2012298319A teaches a method of making an MFC film by applying a furnish containing MFC directly onto a porous substrate, which allows the MFC to be drained and filtered. However, highly beaten pulp or high content of fine cellulose may exhibit high drainage resistance, increasing the risk of web defects occurring during dewatering or reduced material retention.

[0005] Alternatively, HRC papers or films can be made by using a casting technique, which involves applying an HRC suspension onto a non-porous cast substrate, such as a polymeric or metallic substrate, and drying the paper or film by evaporation and / or wet pressing. Films made by casting techniques usually give a more uniform thickness distribution and a smoother surface. Publication EP2771390A4 describes the preparation of MFC films, where an aqueous cellulose nanofiber dispersion is applied onto a paper or polymeric substrate, dried and finally peeled off as a nanofiber film sheet. The problem with casting techniques compared to wire forming and dehydration is that they are less compatible with high-scale manufacturing.

[0006] Another problem with HRC and MFC papers or films is that they are brittle, reducing strain capacity and tear resistance, because the fiber network formed from short fibers may not have the ability to elongate as well as longer fibers. When forming HRC papers or films with low basis weights and calipers, the paper or film may be easily broken during wet web formation, processing or handling.

[0007] Various additives have been explored to address the problems associated with improving the mechanical properties of HRC paper or film. However, while the use of a given additive may solve one particular problem, it may not solve or maintain other physical or mechanical requirements, or may even introduce new problems. For example, the addition of relatively long cellulose fibers as reinforcement in HRC paper or film may improve the mechanical properties of the paper or film, but at the same time may worsen the gas barrier properties and transparency or translucency of the paper or film. The addition of reinforcing fibers may create a more irregular fiber network, increasing the risk of pinhole formation. Other additives may negatively affect the reuse of materials, such as in the form of broke or pre- or post-consumer waste.

[0008] Thus, there remains a need to solve the problems associated with water breakthrough resistance when formulating barrier papers or films containing HRC, and to further improve the physical properties of HRC papers and films. Summary of the Invention

[0009] It is an object of the present disclosure to provide an improved highly beaten cellulose pulp (HRC) composition for preparing barrier papers, films or coatings that obviates or mitigates at least some of the problems of the prior art.

[0010] A further object of the present disclosure is to provide an HRC composition that allows for the production of HRC papers or films with good gas barrier properties and improved mechanical properties.

[0011] A further object of the present disclosure is to enable the production of HRC papers or films that exhibit high oxygen barrier properties, are easy to handle, are easy to produce at high speeds, are easy to process, and / or utilize more cost-effective raw materials.

[0012] The above objectives, as well as other objectives which may be realized by one skilled in the art in light of the present disclosure, are accomplished by various aspects of the present disclosure.

[0013] The present disclosure is based on the realization that the addition of compressed beaten cellulose fibers to an HRC composition can improve the mechanical properties of the HRC paper or film formed from the composition while maintaining the good gas barrier and transparency or translucency properties characteristic of the HRC paper or film without the addition of fibers. In compression beating, the shear applied to the fibers induces fiber wall defects rather than fiber cutting or surface fibrillation or defibrillation. Without wishing to be bound by any particular scientific theory, it is believed that compressed beaten cellulose fibers have a higher tendency to collapse (due to chemical or mechanical damage to the fiber wall) compared to unbeaten or conventionally beaten fibers. This leads to better formation of the formed sheet and improved uniformity, visual appearance, mechanical strength, etc. uniformity. This also allows a relatively high content of compressed beaten fibers to be added to the HRC without inducing problems with the gas barrier properties of the formed film. The addition of compressed beaten cellulose fibers to the HRC composition can also reduce the need for other additional components, retention agents or drainage agents.

[0014] According to a first aspect described herein, there is provided a highly beaten cellulose pulp (HRC) composition for preparing a barrier paper or film, comprising: HRC having a Shopper-Riegler freeness (SR) of >70, measured according to standard ISO 5267-1, in an amount of 50-99% by weight, based on the total dry weight of the HRC composition; Compressed and beaten cellulose pulp, - a Schopper-Riegler freeness (SR) measured according to standard ISO 5267-1 of <30; - Water Retention Value (WRV) > 120%, measured according to standard ISO 23714; The compressed and beaten cellulose pulp is 1 to 50% by weight based on the total dry weight of the HRC composition. A highly beaten cellulose pulp (HRC) composition is provided, comprising:

[0015] The HRC composition may be in the form of a solid composition, such as a dry or substantially dry paper, film, coating or powder, or it may be in the form of a suspension of the HRC composition in a liquid medium, preferably water.

[0016] In some embodiments, the HRC composition is a solid composition. The solid composition comprises: Preferably the moisture content is 20% by weight or less, preferably 15% by weight or less, more preferably 10% by weight or less.

[0017] In some embodiments, the HRC composition is an aqueous suspension. The composition in the form of an aqueous suspension can be used to prepare paper, films or coatings. In some embodiments, the consistency of the aqueous suspension is in the range of 0.1 to 50% by weight, preferably in the range of 0.2 to 30% by weight, more preferably in the range of 0.3 to 20% by weight.

[0018] The drainage of the HRC composition may depend on the type and amount of HRC and press-beaten fibers used, as well as other ingredients added to the composition. In some embodiments, the HRC composition has a Shopper-Riegler (SR) freeness of >20, preferably >30, more preferably >40, measured according to standard ISO 5267-1. In some embodiments, the HRC composition has a Shopper-Riegler (SR) freeness of <95, preferably <90, more preferably <88, measured according to standard ISO 5267-1.

[0019] The HRC composition may comprise a mixture of HRC and compressed beaten cellulose pulp alone, or may comprise a mixture of HRC and compressed beaten cellulose pulp in combination with other raw materials or additives. The HRC composition preferably comprises HRC as a major component based on the total dry weight of the HRC composition. Specifically, the HRC composition comprises HRC at a concentration within the range of 50-99.9 wt. %. In some embodiments, the HRC composition comprises HRC within the range of 55-99 wt. %, preferably within the range of 60-99 wt. %, more preferably within the range of 65-98 wt. % based on the total dry weight of the HRC composition.

[0020] In some embodiments, the HRC has a Schopper-Riegler (SR) freeness of >80, preferably >90, measured according to standard ISO 5267-1.

[0021] In some embodiments, the HRC is microfibrillated cellulose (MFC).

[0022] Microfibrillated cellulose (MFC) in the context of the present disclosure shall mean cellulose particles, fibres or fibrils with a width or diameter between 20 nm and 1000 nm.

[0023] There are various methods to make MFCs, such as single or multi-pass beating, preliminary hydrolysis followed by beating or high shear degradation or defibration of the fibrils. One or more pretreatment steps are usually required to make the production of MFCs energy-efficient and sustainable. Thus, the cellulose fibers of the pulp used in producing MFCs may be raw or enzymatically or chemically pretreated, for example to reduce the amount of hemicellulose or lignin. The cellulose fibers may be chemically modified before fibrillation, the cellulose molecules containing functional groups other than (or more than) those found in the original cellulose. Such groups include, among others, carboxymethyl (CM), aldehyde and / or carboxyl groups (cellulose obtained by N-oxyl-mediated oxidation reactions, e.g. "TEMPO"), or quaternary ammonium (cationic cellulose). After being modified or oxidized by one of the above methods, the fibers are amenable to degradation into MFCs.

[0024] MFCs can be made from wood cellulose fibers, both from hardwood or softwood fibers. They can also be made from microbial sources, agricultural fibers, such as straw pulp, bamboo, bagasse, or other non-wood fiber sources. They can also be made from pulps, including pulps from virgin fibers, such as mechanical, chemical and / or thermomechanical pulps. They can also be made from broke or recycled paper.

[0025] In some embodiments, the HRC is unmodified HRC or chemically modified HRC, or a mixture thereof.

[0026] The HRC composition comprises 1-50 wt. % of compressed and refined cellulose pulp based on its total dry weight. In some embodiments, the HRC composition comprises 1-40 wt. %, preferably 1-30 wt. %, more preferably 2-20 wt. % of compressed and refined cellulose pulp based on its total dry weight. The inventors have found that 1-30 wt. % of compressed and refined cellulose pulp can be added to the HRC composition without affecting the barrier properties of the film formed with the HRC composition. However, relatively larger amounts can also be used where a slight decrease in barrier properties may be acceptable.

[0027] Compression beating, sometimes referred to as internal fibrillation beating or internal fibrillation, induces fiber wall defects rather than fiber cutting or surface fibrillation or defibrillation. Fiber wall defects include fiber wall delamination and internal fibrillation. Preferably, compression beating damages the fiber wall but at a very low level of fiber fibrillation. Ideally, there is no surface fibrillation at all.

[0028] Damage to the fiber walls allows the compressed beaten cellulose fibers to disintegrate more easily, resulting in a denser sheet.

[0029] Fiber wall defects can be directly visualized by microscopy. The lack of surface fibrillation can be demonstrated by staining the compression beaten fibers, for example with Simons' stain. Fiber wall defects can also be detected indirectly from analysis of fiber morphology, for example using a Valmet FS5 fiber analyzer.

[0030] Compressive beating can be carried out, for example, using a vibrating grinder, a friction shear device, and a roll-wear device. Examples of compressive refiners include, but are not limited to, roll refiners, vibrating refiners, vibrating grinders, lumpen mills, rotor-rotor grinders or rotor-rotor mixers (using counter-rotating or co-rotating rotors, for example, Atrex G series from Megatrex), or a compressive E-compressor.

[0031] Compressive beating is preferably carried out at a consistency >3 wt%, more preferably at a consistency >4 wt%. To facilitate the compressive beating, it is preferred to increase the consistency to >5 wt%, >7 wt%, >9 wt%, >12 wt% or >15 wt%.

[0032] Compressive beating is preferably carried out at a pH value in the range of 5-11, preferably in the range of 6-9.

[0033] The compression beating is preferably carried out at a temperature within the range of 20 to 85°C, more preferably within the range of 30 to 70°C.

[0034] In some embodiments, the compressively beaten cellulose pulp has been subjected to alkaline extraction or enzymatic treatment, such as with cellulases or hemicellulases or combinations thereof, before, during, and / or after compressive beating, which activates the fibers and makes the fiber walls more susceptible to collapse or flattening and the introduction of fiber wall defects.

[0035] In some embodiments, a polysaccharide such as MFC or CMC is added to the cellulose pulp for compression beating in an amount of 0.5 to 100 kg / tn of dry weight. In a preferred embodiment, a mixture of CMC and MFC is added to the cellulose pulp for compression beating.

[0036] The compressed and refined cellulose pulp may be, for example, a compressed and refined cellulose pulp obtained from hardwood or softwood. In some embodiments, the compressed and refined cellulose pulp is a compressed and refined kraft pulp.

[0037] The compressed and beaten cellulose fibers are larger than the highly beaten fibers of HRC or the microfibrils of MFC. The size of the compressed and beaten cellulose fibers may depend on the source of the fibers, for example, hardwood or softwood. In some embodiments, the fiber width of the compressed and beaten cellulose fibers of the HRC composition is 10 μm or more, as measured using an FS5 optical fiber analyzer (Valmet). In some embodiments, the fiber width of the compressed and beaten cellulose fibers of the HRC composition is in the range of 10-31 μm, preferably in the range of 10-29 μm, more preferably in the range of 10-27 μm, as measured using an FS5 optical fiber analyzer (Valmet). HRC is usually made of cellulose with significantly smaller fiber widths, and MFC is usually made of cellulose particle fibers or fibrils with at least one dimension in the range of 20-1000 nm.

[0038] Compressively beaten cellulose pulp is characterized by a very low Schopper-Riegler (SR) freeness of <30, measured according to standard ISO 5267-1, combined with a relatively high water retention value (WRV) of >120%, measured according to standard ISO 23714.

[0039] In some embodiments, the compression-beaten cellulose pulp has a Shopper-Riegler (SR) freeness, measured according to standard ISO 5267-1, of <20, preferably <15. In some embodiments, the compression-beaten cellulose pulp has an even lower Shopper-Riegler (SR) freeness, measured according to standard ISO 5267-1, such as <13 or <11.

[0040] In some embodiments, the compressed beaten cellulose pulp has a water retention value (WRV) measured according to standard ISO 23714 of >130%, preferably >140%, more preferably >150%.

[0041] In some embodiments, the compressed beaten cellulose pulp has a Water Retention Value (WRV) measured according to standard ISO 23714 of <210%, preferably <200%, more preferably <190%.

[0042] The compression-beaten cellulose pulp is also characterized by a high fiber curl value, in some embodiments, the compression-beaten cellulose pulp has a fiber curl value of >10%, preferably >15%, more preferably >20%, as measured using an FS5 fiber analyzer (Valmet).

[0043] In some embodiments, the compressed beaten cellulose pulp has an average fiber length in the range of 0.2-4 mm, preferably in the range of 0.3-2 mm, more preferably in the range of 0.5-2 mm, as measured using an FS5 fiber analyzer (Valmet). Average fiber length as used herein refers to the average fiber length (Lc(n)ISO) measured according to standard ISO 16065-2 using an FS5 optical fiber analyzer (Valmet).

[0044] The formulation of the HRC composition may vary depending on the intended use of the HRC composition and the intended mode of application or formation of the HRC composition paper, film or coating. The HRC composition may contain a wide range of ingredients in different amounts to improve the ultimate performance of the HRC composition paper, film or coating.

[0045] The HRC composition may further include additives such as starch, fillers, retention agents, flocculants, deflocculants, dry strength agents, softeners, lubricants, wet strength agents, crosslinkers, colorants or dyes, defoamers, adhesion promoters, biocides, pH adjusters, UV inhibitors, or mixtures thereof. The HRC composition may also include additives that may improve various physical properties of the HRC composition and / or the paper, film, or coating formed therefrom, such as latex and / or polyvinyl alcohol (PVOH) to enhance the spreadability of the coating.

[0046] In some embodiments, the HRC composition further comprises a water soluble polymer, preferably PVOH, selected from the group consisting of starch, polyvinyl alcohol (PVOH), cellulose derivatives, hemicellulose, polyacrylamide, polydiallyldimethylammonium chloride (PDADMAC), polyvinylamine (PVAm), polyethyleneimine (PEI), polyamidoamine epichlorohydrin (PAE), protein or mixtures thereof.

[0047] In some preferred embodiments, the water-soluble polymer is PVOH. The PVOH may be a single type of PVOH or may comprise a mixture of two or more types of PVOH, e.g., with different degrees of hydrolysis or viscosities or with different functional groups. The degree of hydrolysis of the PVOH may be, for example, in the range of 80-99 mol%, preferably in the range of 88-99 mol%. Furthermore, the PVOH may preferably have a viscosity of more than 5 mPa×s, measured in a 4% aqueous solution at 20° C. according to standard DIN 53015 / JIS K 6726.

[0048] In some embodiments, the HRC composition comprises, based on its total dry weight, in the range of 0.1-50 wt %, preferably in the range of 1-30 wt %, more preferably in the range of 1-10 wt % of the water-soluble polymer.

[0049] In some embodiments, the HRC composition further comprises a pigment. The pigment may comprise, for example, inorganic particles of talc, silicates, carbonates, alkaline earth metal carbonates and ammonium chlorides, or oxides, such as transition metal oxides and other metal oxides. The pigment may also comprise nano-sized pigments, such as nanoclays and nanoparticles of layered mineral silicates, such as those selected from the group including montmorillonite, bentonite, kaolinite, hectorite, and hallyosite.

[0050] In order to maintain the gas barrier properties of the paper or film or coating formed with the HRC composition, the particle size and concentration of the pigment should preferably be low. In some embodiments, the pigment is selected from the group consisting of nanoclays and nanoparticles of layered mineral silicates, more preferably bentonite.

[0051] In some embodiments, the HRC composition comprises a pigment in the range of 0.1-20 wt %, preferably in the range of 0.5-15 wt %, more preferably in the range of 1-10 wt %, based on the total dry weight of the HRC composition.

[0052] The HRC composition of the first embodiment above is useful for preparing HRC paper or film, for example as a barrier film for packaging laminates based on paper or cardboard. The improved drainage of the HRC composition of the present invention compared to a similar HRC composition that does not contain compressed beaten cellulose pulp, for example an HRC composition that is entirely composed of HRC, allows for quick dewatering of the film formed with the HRC composition, reducing the risk of web defects occurring during dewatering. The resulting film has good gas barrier properties and improved mechanical properties compared to a similar HRC paper or film formed from an HRC composition that does not contain compressed beaten cellulose pulp.

[0053] Thus, according to a second aspect described herein, there is provided an HRC paper or film comprising an HRC composition as defined herein in relation to the first aspect.

[0054] The term "HRC paper or film" as used herein refers to a material formed into a thin, continuous sheet, usually made of a predominantly highly refined cellulose pulp (HRC), by dry weight, that appears either as a paper or as a film, depending on the fiber composition of the HRC paper or film.

[0055] The HRC paper or film may be a free-standing HRC paper or film, an HRC coating on a substrate, or an HRC layer of a multi-layer material. The HRC paper or film may be prepared, for example, by wire forming and dewatering, casting, coating, or wet laid processes.

[0056] The free-standing paper or film should preferably have sufficient thickness, mechanical strength and stiffness in order to handle it, e.g., to wind, unwind, coat and / or laminate to a paper or cardboard substrate. In some embodiments, the basis weight of the HRC paper or film is between 10 and 100 g / m 2 Within the range of 12 to 50 g / m 2 More preferably, it is within the range of 15 to 40 g / m 2 is within the range.

[0057] In some embodiments, the HRC paper or film is a substitute for a coating layer on a paper or cardboard substrate. When the paper or film is formed or coated on a paper or cardboard substrate and then dewatered and dried, the resulting HRC paper or film may appear as a coating layer on the paper or cardboard substrate. The HRC paper or film in the form of a coating layer on a paper or cardboard substrate can be significantly thinner than a free-standing HRC paper or film, since the paper or cardboard substrate provides mechanical strength and stiffness for handling purposes. Thus, in some embodiments, the basis weight of the HRC paper or film in the coated form is 1 to 30 g / m 2 within the range of 1 to 20 g / m 2 or more preferably in the range of 1 to 10 g / m 2may be in the range.

[0058] In some embodiments, the density of the HRC paper or film is >750 kg / m 3 , preferably >850 kg / m 3 , more preferably >900 kg / m 3 If the HRC paper or film is calendered, the density may be even higher.

[0059] The present disclosure is based on the realization that the use of compressed and beaten cellulose fibers can improve the mechanical properties and flexibility of HRC paper or film while maintaining the good gas barrier properties characteristic of HRC paper or film without the addition of natural or synthetic fibers that cause a decrease in barrier properties. The addition of compressed and beaten cellulose pulp to HRC paper or film improves the mechanical strength of the paper or film compared to a corresponding HRC paper or film that does not contain compressed and beaten cellulose pulp, i.e., in which the compressed and beaten cellulose fibers are replaced by HRC. In some embodiments, the HRC paper or film has a tear index measured according to standard ISO 1974 that is at least 5% higher, preferably at least 10% higher, more preferably at least 15% higher than the tear index of a corresponding paper or film made entirely of the same type of HRC as that used in the HRC composition.

[0060] In some embodiments, the HRC paper or film has an oxygen transfer rate (OTR) of 30 cc / m2 or less, measured according to standard ASTM F-1927-98 at 50% relative humidity and 23° C. 2 / 24h / atm or less, preferably 20cc / m 2 / 24h / atm.

[0061] In some embodiments, the HRC paper or film has a KIT value of greater than 10, measured according to standard TAPPI T559.

[0062] In some embodiments, the HRC paper or film has a transparency of at least 75%, preferably at least 80%, measured according to standard DIN 53147. The transparency of the HRC paper or film may depend on the amount of compressed and beaten cellulose pulp.

[0063] In some embodiments, the HRC paper or film has a PPS surface smoothness measured according to ISO 8791-4:2007 of <5 μm, preferably <4 μm, more preferably <3 μm.

[0064] The HRC papers or films or coatings of the present invention are often used as barrier layers in multi-layer materials, such as paper- or cardboard-based packaging laminates containing two or more plies.

[0065] According to a third aspect described herein, A base layer; an HRC layer comprising the HRC composition defined herein in relation to the first aspect; A multi-layer material is provided comprising at least one

[0066] In some embodiments, the HRC layer is an HRC paper or film as described above in connection with the second aspect.

[0067] In multi-layer materials, the HRC layer can be adhered to the substrate layer directly or through one or more intermediate layers. For example, the HRC layer can be coated or wet-laid directly onto the substrate layer, or an intermediate adhesive layer can be used to laminate the HRC paper or film to the substrate layer.

[0068] In some embodiments, the substrate layer is paper or cardboard.

[0069] In some embodiments, the paper or cardboard has a base weight of 20 to 500 g / m 2 Within the range of 80 to 400 g / m 2 is within the range.

[0070] In some embodiments, the multi-layer material is a paper or cardboard comprising two or more plies, at least one ply comprising the HRC composition described above in connection with the first aspect.

[0071] In some embodiments, at least one ply comprising the HRC composition is an HRC paper or film as described above in connection with the second aspect.

[0072] In some embodiments, the multi-layer material further comprises one or more heat-sealable layers, for example one or more polyethylene layers.

[0073] HRC suspensions containing compressed and beaten cellulose pulp are easier to dewater and have improved strength and running stability, for example in processing machines, compared to HRC suspensions that do not contain compressed and beaten cellulose pulp.

[0074] According to a fourth aspect described herein, A method for preparing an HRC paper or film comprising the steps of: a) preparing an aqueous suspension of an HRC composition as defined herein in relation to the first aspect; b) forming a web of the aqueous HRC composition; c) drying the web to obtain an HRC paper or film; A method is provided that includes:

[0075] The aqueous suspension of the HRC composition can be prepared in a variety of ways. For example, the aqueous suspension of the HRC composition can be prepared by mixing a dry HRC with a dry compressed and beaten cellulose pulp and dispersing the dry mixture in water or by adding the compressed and beaten cellulose pulp to the aqueous HRC suspension. The compressed and beaten cellulose pulp can be added in a dry or thick consistency. Thick consistency means that the consistency of the suspension is greater than 5% by weight, preferably greater than 10% by weight, more preferably greater than 15% by weight.

[0076] In some embodiments of the above method, step a) comprises mixing an HRC or MFC having a Shopper-Riegler (SR) freeness >70, preferably >80, more preferably >90, measured according to standard ISO 5267-1, with a compressed beaten cellulose pulp having a Shopper-Riegler (SR) freeness <30, preferably <20, more preferably <15, measured according to standard ISO 5267-1.

[0077] In some embodiments, step a) is carried out in an aqueous suspension. HRC having a Shopper-Riegler (SR) freeness of >70, measured according to standard ISO 5267-1, is present in an amount of 50-99% by weight based on the total dry weight of the HRC composition; Compressed and beaten cellulose pulp, - a Schopper-Riegler freeness (SR) measured according to standard ISO 5267-1 of <30; - Water Retention Value (WRV) > 120%, measured according to standard ISO 23714; Compressed and beaten cellulose pulp is 1 to 50% by weight based on the total dry weight of the HRC composition; The method includes the step of mixing the above.

[0078] In some embodiments, the method further comprises co-beating HRC with the compression-beaten cellulose pulp.

[0079] In some embodiments, the web formation in step b) comprises wire forming and dewatering, casting, coating or wet laid processes. In some embodiments, the web formation in step b) comprises wire forming and dewatering, preferably in a paper machine, such as a Fourdrinier type paper machine.

[0080] In some embodiments, the drying step of step c) is carried out at a temperature above 50°C, preferably above 70°C, more preferably above 90°C. Drying temperature refers to the temperature of the HRC paper or film. The temperature of the drying source may be much higher than the actual film. Drying means that the solids concentration of the HRC paper or film after drying is at least 80% by weight, preferably at least 85% by weight, more preferably at least 90% by weight.

[0081] In some embodiments, the resulting HRC paper or film is further subjected to a calendering process to obtain a PPS surface smoothness of <5 μm, preferably <4 μm, more preferably <3 μm, measured according to ISO 8791-4:2007.

[0082] The present disclosure is based on the realization of the present invention that by using pressure-beaten cellulose pulp, it is possible to improve the mechanical properties of HRC paper or film while maintaining the good gas barrier properties that are characteristic of fiber-free HRC paper or film.

[0083] According to a fifth aspect described herein, there is provided a use of compressed beaten cellulose pulp as a dewatering agent or as a strength enhancing agent in an HRC composition for preparing a barrier paper or film.

[0084] In some embodiments, the compressed beaten cellulose pulp is further defined as described above in relation to the first aspect.

[0085] In some embodiments, the HRC composition of the fifth aspect is an HRC composition as described above in relation to the first aspect.

[0086] The term "wt. %" as used herein (eg, in relation to a pulp composition or pulp fraction) refers to weight percent based on the total dry weight of the composition.

[0087] The term "consistency" as used herein (eg, in relation to a pulp composition or pulp fraction) refers to the weight percentage of dry solid matter in a composition relative to the total weight of the composition.

[0088] While the present invention has been described with reference to various exemplary embodiments, it will be apparent to those skilled in the art that various modifications can be made and equivalents can be substituted for those elements without departing from the scope of the invention. In addition, many modifications can be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is not intended that the invention be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but rather, the invention is intended to include all embodiments falling within the scope of the appended claims. EXAMPLES

[0089] Wet-laid (water drained through a membrane) and cast-formed papermaking methods were used to produce 30 g / m 2 Various thin barrier films were prepared. The films were dried at 80°C on a rotary drum.

[0090] Highly beaten cellulose pulp (HRC) was prepared from 100% kraft pulp beaten to a Schopper-Riegler (SR) value of approximately 95, measured according to the ISO 5267-1 standard. The pH of the pulp was 7.2, the amount of long fibers (>0.2 mm) was 19.8 million fibers / g, the fines A content was 47% and the fines B content was 47%, measured by using an FS5 fiber analyzer (Valmet) at the 5 μm setting.

[0091] Compressive beating was carried out on bleached kraft pulp to give the following physical properties:

[0092] Compression-beaten cellulose pulp was prepared by compression beating of bleached kraft pulp. Unbeaten bleached kraft pulp was used as a comparison. The analytical results of unbeaten and compression-beaten bleached kraft pulps are presented in Table 1. Compression beating did not affect surface fibrillation or drainage resistance. Fine A content and fine B content remained at low levels, whereas fiber curl increased significantly, suggesting that the fiber walls were damaged. TIFF2025512343000001.tif114170

[0093] Example 1 (Comparative) - 100% highly beaten kraft pulp 33.8 g / m2 from 100% highly beaten bleached kraft 2 Thin barrier films were prepared. The films were analyzed and the results are shown in Table 2. The resulting films had good oxygen barrier properties, but the furnish showed very high water break resistance.

[0094] Example 2 (Comparative) - Addition of 10% Slightly Beaten Bleached Kraft Pulp 10% by weight of never-dried bleached softwood kraft pulp, beaten at 100 kWh / t in the lab Voith-Sulzer to a Schopper-Riegler (SR) value of 19, was added to the same type of highly beaten bleached kraft pulp used in Example 1. 2 A thin barrier substrate was prepared. The thin substrate was dehydrated and dried. The film was analyzed and the results are shown in Table 2. The dehydration rate was not significantly affected, but the density was significantly reduced. Compared to Example 1, the reduced density is associated with a clear deterioration in gas barrier properties.

[0095] Example 3 - Addition of 10% Compressed Beaten Pulp 10% by weight of compressed beaten pulp was added to the same type of highly beaten bleached kraft pulp used in Example 1. 2 A thin barrier substrate was prepared. The thin substrate was dehydrated and dried. The film was analyzed and the results are shown in Table 2. The results show that the water drainage resistance was reduced, but also the density was significantly higher compared to Example 2. The gas barrier properties were at a good level.

[0096] Example 4 - Addition of 20% Compressed Beaten Pulp 20% by weight of compressed beaten pulp was added to the same type of highly beaten bleached kraft pulp used in Example 1. 2 A thin barrier substrate was prepared. The thin substrate was dewatered and dried. The film was analyzed and the results are shown in Table 2. The results show that the water drainage resistance was significantly reduced, but also that the density was clearly higher compared to Comparative Example 2. Despite the higher addition of compressed beaten pulp, the gas barrier properties were still at a good level. TIFF2025512343000002.tif77170Unless otherwise specified, the physical properties or parameters discussed in this disclosure are measured according to the following standard methods. The OTR was measured at 3°C ​​and 50% RH using a Mocon instrument.

Claims

1. A highly beaten cellulose pulp (HRC) composition for preparing barrier paper or barrier film, HRC having a Shopper-Liegra (SR) filtration degree of >70, as measured according to standard ISO 5267-1, is present in an amount of 50-99% by weight relative to the total dry weight of the HRC composition. It is compressed and beaten cellulose pulp, - Having a Shopper-Liegra filtration rate (SR) of <30 as measured according to standard ISO 5267-1, - Having a water retention value (WRV) of >120%, as measured according to standard ISO 23714. Compressed and beaten cellulose pulp is added in an amount of 1 to 50% by weight relative to the total dry weight of the HRC composition. A highly beaten cellulose pulp (HRC) composition containing the following.

2. The HRC composition according to claim 1, which is an aqueous suspension.

3. The HRC composition according to claim 2, wherein the consistency of the aqueous suspension is in the range of 0.1 to 50% by weight, preferably in the range of 0.2 to 30% by weight, and more preferably in the range of 0.3 to 20% by weight.

4. The HRC composition according to claim 1, having a Schoper-Liegura (SR) filtration degree of >20, preferably >30, more preferably >40, as measured according to standard ISO 5267-1.

5. The HRC composition according to claim 4, having a Schoper-Liegura (SR) filtration degree of <95, preferably <90, more preferably <88, as measured according to standard ISO 5267-1.

6. The HRC composition according to claim 1, comprising HRC in an amount of 55 to 99% by weight, preferably 60 to 99% by weight, and more preferably 65 to 98% by weight, based on the total dry weight of the HRC composition.

7. The HRC composition according to claim 1, comprising 1 to 40% by weight, preferably 1 to 30% by weight, and more preferably 2 to 20% by weight, of compressed and beaten cellulose pulp based on the total dry weight of the HRC composition.

8. The HRC composition according to claim 1, wherein HRC is microfibrillated cellulose (MFC).

9. The HRC composition according to claim 1, wherein HRC is unmodified HRC, chemically modified HRC, or a mixture thereof.

10. The HRC composition according to claim 1, wherein the HRC has a Schoper-Liegura (SR) filtration capacity of >80, preferably >90, as measured according to the standard ISO 5267-1.

11. The HRC composition according to claim 1, wherein the compressed and beaten cellulose pulp has a Schoper-Liegura (SR) filtration capacity of <20, preferably <15, as measured according to standard ISO 5267-1.

12. The HRC composition according to claim 1, wherein the compressed and beaten cellulose pulp has a water retention value (WRV) of >130%, preferably >140%, more preferably >150%, as measured according to standard ISO 23714.

13. The HRC composition according to claim 1, wherein the compressed and beaten cellulose pulp has a water retention value (WRV) of <210%, preferably <200%, more preferably <190%, as measured according to standard ISO 23714.

14. The HRC composition according to claim 1, wherein the compressed and beaten cellulose pulp has a fiber curl value of >10%, preferably >15%, more preferably >20%, as measured using an FS5 fiber analyzer (Valmet).

15. The HRC composition according to claim 1, wherein the compressed and beaten cellulose pulp has an average fiber length (Lc(n)ISO) in the range of 0.2 to 4 mm, preferably in the range of 0.3 to 2 mm, more preferably in the range of 0.5 to 2 mm, as measured using an FS5 fiber analyzer (Valmet).

16. The HRC composition according to claim 1, further comprising a water-soluble polymer selected from the group consisting of starch, polyvinyl alcohol (PVOH), cellulose derivatives, hemicellulose, polyacrylamide, polydiallyldimethylammonium chloride (PDAMAC), polyvinylamine (PVAm), polyethyleneimine (PEI), protein, or mixtures thereof, preferably PVOH.

17. The HRC composition according to claim 16, comprising a water-soluble polymer in an amount of 0.1 to 50% by weight, preferably 1 to 30% by weight, and more preferably 1 to 10% by weight, based on the total dry weight of the HRC composition.

18. Furthermore, the HRC composition according to claim 1 further comprises a pigment, preferably a pigment selected from the group consisting of layered mineral silicate nanoclays and nanoparticles, more preferably bentonite.

19. The HRC composition according to claim 18, comprising a pigment in an amount of 0.1 to 20% by weight, preferably 0.5 to 15% by weight, and more preferably 1 to 10% by weight, based on the total dry weight of the HRC composition.

20. HRC paper or film comprising the HRC composition according to any one of claims 1 to 19.

21. 10-100 g / m ２ Within the range of preferably 12 to 50 g / m² ２ Within the range of 15 to 40 g / m², more preferably 15 to 40 g / m² ２ The HRC paper or film according to claim 20, having a basis weight within the range.

22. The HRC paper or film according to claim 20, having a tear index at least 5% higher, preferably at least 10% higher, more preferably at least 15% higher than the tear index of the corresponding paper or film which is formed entirely of the same type of HRC as used in the HRC composition, as measured according to standard ISO 1974.

23. 30 cc / m³ measured according to standard ASTM F-1927-98 at 50% relative humidity and 23°C. ２ Less than 24h / atm, preferably 20cc / m³ ２ HRC paper or film according to claim 20, having an oxygen transport rate (OTR) of less than 24h / atm.

24. The HRC paper or film according to claim 20, having a KIT value greater than 10 as measured according to the TAPPI T559 standard.

25. The HRC paper or film according to claim 20, having a PPS surface smoothness of <5 μm, preferably <4 μm, more preferably <3 μm, as measured in accordance with ISO 8791-4:2007.

26. A base layer and An HRC layer comprising the HRC composition according to any one of claims 1 to 19 A multilayer material containing at least [a certain element].

27. The multilayer material according to claim 26, wherein the base layer is paper or cardboard.

28. Paper or cardboard, 20-500 g / m² ２ Within the range of preferably 80 to 400 g / m² ２ The multilayer material according to claim 27, having a basis weight within the range.

29. A method for preparing HRC paper or film, a) A step of preparing an aqueous suspension of the HRC composition according to any one of claims 1 to 19, b) A step of forming a web of aqueous HRC composition, c) A step of drying the web to obtain HRC paper or film. Methods that include...

30. Step a) is performed in an aqueous suspension, HRC having a Shopper-Liegra (SR) filtration degree of >70, as measured according to standard ISO 5267-1, is present in an amount of 50-99% by weight relative to the total dry weight of the HRC composition. It is compressed and beaten cellulose pulp, - Having a Shopper-Liegra filtration rate (SR) of <30 as measured according to standard ISO 5267-1, - Having a water retention value (WRV) of >120%, as measured according to standard ISO 23714. Compressed and beaten cellulose pulp is added in an amount of 1 to 50% by weight relative to the total dry weight of the HRC composition. The method according to claim 29, comprising mixing the following.

31. The method according to claim 30, further comprising co-beating HRC together with compressed and beaten cellulose pulp.

32. The method according to claim 29, wherein the obtained HRC paper or film is subjected to calendering so that the PPS surface smoothness, as measured in accordance with ISO 8791-4:2007, is <5 μm, preferably <4 μm, more preferably <3 μm.

33. The use of compressed and beaten cellulose pulp as a dehydrating agent or strength-enhancing agent in an HRC composition for preparing barrier paper or barrier film.