BR122021013130B1 - COMPOSITIONS FOR INK AND INK IN CANS - Google Patents

Abstract

The present invention relates to a paint composition comprising microfibrillated cellulose, binder and solvent. microfibrillated cellulose is present in an amount ranging from approximately 0.1% to approximately 10% by weight based on the total weight of the paint composition. furthermore, it refers to a paint in a can comprising the paint composition as defined in the present invention.

Description

TECHNICAL FIELD

[001] The present invention relates to a milling base for paint comprising microfibrillated cellulose and optionally co-processed particulate inorganic material as a pigment or diluent and to a paint composition comprising microfibrillated cellulose and optionally co-processed particulate inorganic material.

BACKGROUND

[002] Paints, including water-based decorative paints, contain many ingredients. The main ingredients are pigments such as TiO2 and thinners such as kaolin, talc or calcium carbonate, which are added to generate light scattering and give the paint its whiteness and opacity and in the case of colored paints provide strong, bright colors. These are accompanied by one or more binders, typically synthetic latex polymers, which bind to pigments and thinners to provide a strong, cohesive dry film. Other minor additives such as co-solvents, plasticizers, defoamers, biocides and rheology modifiers are also common. Conventional rheology modifiers, such as hydroxyethyl cellulose, are used to prevent sedimentation of pigments and thinners in the can, to give the product a long shelf life and to avoid the need for extensive and rigorous agitation before use. as well as to prevent ink dripping once applied to a substrate. These additives give the paint a high shear reduction or pseudoplastic rheological profile; the paint is viscous or even semi-solid at rest, but its viscosity is substantially reduced by the shearing action of a brush or roller so that it can be easily transferred from the can to the substrate. For example, a solution of up to 5% by weight hydroxyethyl cellulose in the water used to dilute a paint is usually sufficient to impart the desired rheology to the paint formulation.

[003] Hydroxyethyl cellulose (and related products such as carboxymethyl cellulose) is typically produced from a bleached chemical pulp source. However, its production requires reaction and dissolution of cellulose in concentrated and caustic solutions and is an inherently expensive ink component. Therefore, there is a need for new and less expensive rheology modifiers for paints, particularly those that can bring other benefits to the paint, such as improved whiteness, opacity, gloss and wet rub resistance.

[004] The present invention seeks to provide alternative and/or improved components such as rheology modifiers for ink products that can be incorporated into the ink in addition to or in place of conventional rheology modifiers such as hydroxyethyl cellulose while maintaining or even improves the physical/mechanical, optical and post-application properties of the paint product. As such, the present inventors have surprisingly found that a composition comprising microfibrillated cellulose and optionally a co-processed particulate inorganic material can be used as a rheology modifier in the paint while maintaining or even improving the physical/mechanical, optical and post-application properties of the paint. ink.

SUMMARY OF THE INVENTION

[005] According to a first aspect, there is provided a grinding base for ink, which comprises microfibrillated cellulose. The microfibrillated cellulose is present in an amount ranging from approximately 0.1% to approximately 10% by weight based on the total weight of a formulated paint composition of said mill base. In one embodiment, the milling base also comprises co-processed particulate inorganic material as the main pigment and/or extender pigment, wherein said particulate organic material is co-processed with a fibrous substrate comprising cellulose during the preparation of said microfibrillated cellulose.

[006] According to a second aspect, there is provided an ink composition comprising microfibrillated cellulose, binder and solvent. The microfibrillated cellulose is present in an amount ranging from approximately 0.1% to approximately 10% by weight based on the total weight of the ink composition. In one embodiment, the ink composition is formulated starting from a grinding base of the first aspect of the invention.

[007] According to a third aspect, the present invention is directed to the use of microfibrillated cellulose as described in this case as a rheology modifier in a grinding base for paint or paint composition.

[008] According to a fourth aspect, the present invention is directed to the use of microfibrillated cellulose as described in this case as a replacement or as a partial replacement for conventional cellulose-derived rheology modifier in a milling base for paint or paint composition. ink.

[009] According to the sixth aspect, there is provided a substrate coated with the ink composition of the second aspect of the invention.

[0010] According to a seventh aspect, there is provided a canned paint comprising the paint composition of the second aspect of the invention.

BRIEF DESCRIPTION OF THE FIGURES

[0011] Figure 1 presents the rheology profiles (viscosity as a function of the shear rate) of several comparative formulations and examples of paint formulations.

[0012] Figure 2 presents the rheology profiles (viscosity as a function of the shear rate) of other comparative formulations and examples of paint formulations.

DETAILED DESCRIPTION

[0013] The terms "grinding base" or "grinding base for paint" used herein means a composition that can be formulated into paint. The milling base will typically comprise a portion of liquid ink components as well as main pigment and optional components of pigment thinners and other conventional additives as described below. Thus, the grinding base includes fully formulated paint components other than most of the solvent (eg water) and binder (eg a latex).

[0014] The terms "ink" or "formulated paint" or "fully formulated paint" used in this case mean a composition comprising main pigment, optional diluent for pigment, solvent and binder and other optional additives suitable for use in paint, which is in a form suitable for application to a substrate, eg an article of manufacture (eg a handcrafted article, piece of furniture or an automobile and the like) or a surface, eg the surface of a building element (eg example, internal walls, ceilings and floors of a place of residence) and the like.

[0015] By microfibrillation it is understood a process in which the cellulose microfibrils are released or partially released as individual species or as smaller aggregates compared to the fibers of the pre-microfibrillated pulp. Typical cellulose fibers (ie, pre-microfibrillated pulp) include larger aggregates of hundreds or thousands of individual cellulose microfibrils. By microfibrillation of cellulose, particular characteristics and properties, including but not limited to the characteristics and properties described herein, are imparted to microfibrillated cellulose and compositions including microfibrillated cellulose.

[0016] As used herein the "co-processed inorganic particulate material" refers to particulate inorganic material produced by the methods for microfibrillation of fibrous substrates comprising cellulose in the presence of an inorganic particulate material as described in this case.

[0017] Unless otherwise stated, the particle size properties cited in this case for particulates of inorganic material are as measured by the well-known conventional method employed in the laser light scattering technique, which uses a Malvern machine Mastersizer S as provided by Malvern Instruments Ltd (or by other methods that provide essentially the same result). In the laser light scattering technique, particle size in powders, suspensions and emulsions can be measured using laser beam diffraction, based on an application of Mie or Frauenhofer theory. Such a machine provides measurements and a graphical comparison of the cumulative percentage by volume of particles that have a size, referred to in the art as the 'equivalent spherical diameter' (e.s.d), less than the given e.s.d values. The mean particle size d50 is the value determined in this way of the e.s.d of the particle in which there is 50% by volume of the particles having an equivalent spherical diameter less than the d50 value.

[0018] Alternatively, where stated, the particle size properties cited in this case for particulates of inorganic material as are measured in a well-known manner by sedimentation of the particulate material in a fully dispersed state in an aqueous medium using a Sedigraph 5100 machine supplied by Micromeritics Instruments Corporation, Norcross, Georgia, USA (phone: +1 770 662 3620; web-site: www.micromeritics.com), named "Micromeritics Sedigraph 5100 unit". Such a machine provides measurements and a graphical comparison of the cumulative percentage by weight of particles that have a size, termed in the technique 'equivalent spherical diameter' (e.s.d), smaller than the given e.s.d values. The d50 mean particle size is the value determined in this way from the e.s.d particle where 50% by weight of the particles have an equivalent spherical diameter less than the d50 value.

[0019] Unless otherwise stated, the particle size properties of microfibrillated cellulose materials are as measured by the well-known conventional method employed in the laser light scattering technique, which uses a Malvern Mastersizer S machine as provided. by Malvern Instruments Ltd (or by other methods which give essentially the same result). Details of an example procedure used to characterize the particle size distributions of mixtures of inorganic particle material and microfibrillated cellulose using a Malvern Mastersizer S machine are given in WO-A-2010/131016 on page 40, line 32 to to page 41, line 34. Grinding base

[0020] The milling base comprises microfibrillated cellulose, wherein the microfibrillated cellulose is present in an amount ranging from approximately 0.1% to approximately 10% by weight, based on the total weight of a paint composition formulated starting from said base for grinding and which includes solvent, binder and any other additives. Thus, based on the total weight of the milling base, the microfibrillated cellulose can be present in an amount of from approximately 0.1 to approximately 20% by weight.

[0021] In one embodiment, the microfibrillated cellulose is present in an amount ranging from approximately 0.1% to approximately 8% by weight, based on the total weight of a paint composition formulated starting from said milling base, by for example, from approximately 0.1% to approximately 6% by weight or from approximately 0.2% to approximately 5% by weight or from approximately 0.3% to approximately 5% by weight or from approximately 0.4% by weight to approximately 5% by weight or from approximately 0.4% to approximately 4.5% by weight or from approximately 0.4% to approximately 4% by weight or from approximately 0.4% to approximately 3.5% by weight or from approximately 0.4% to approximately 3% by weight or from approximately 0.4% to approximately 2.5% by weight or from approximately 0.4% to approximately 2% by weight.

[0022] Thus, based on the total weight of the milling base (milled matter), the microfibrillated cellulose may be present in an amount of from approximately 0.1% to approximately 18% by weight, for example from approximately 0. 2% to approximately 16% by weight or from approximately 0.3 to approximately 14% by weight or from approximately 0.4% to approximately 12% by weight or from approximately 0.5% to approximately 10% by weight or from approximately 0.5% to approximately 9% by weight or from approximately 0.5% to approximately 8% by weight or from approximately 0.5% to approximately 7% by weight or from approximately 0.5% to approximately approximately 6% by weight or from approximately 0.5% to approximately 5% by weight or from approximately 0.5% to approximately 4% by weight or from approximately 0.5% to approximately 3% by weight.

[0023] Microfibrillated cellulose can be included as a rheology modifier.

[0024] In one embodiment, microfibrillated cellulose can be obtained by a method comprising microfibrillating a fibrous substrate comprising cellulose in a suitable environment, advantageously an aqueous environment, by milling in the presence of a milling medium that needs to be removed after milling is complete. Milling is carried out in the absence of a particulate inorganic material that can be milled. A particulate inorganic material that can be milled is a material that would be milled in the presence of the milling medium. In one embodiment, grinding is performed in a tower mill, a sieve mill, a medium stirred mill, or a medium stirred debris. Suitable methods for the preparation of microfibrillated cellulose are described in WO-A-2010/131016, see in particular pages 33, line 17 to page 40, line 24, the entire contents of which are hereby incorporated by reference.

[0025] The particulate grinding medium can be of a natural or synthetic material. The grinding medium can, for example, comprise balls, spheres or pellets of any hard mineral, ceramic or metallic material. Such materials may, for example, include alumina, zirconia, zirconium silicate, aluminum silicate or the mullite-rich material which is produced by calcining kaolinitic clay at a temperature in the range of from approximately 1300°C to approximately 1800°C . For example, in some embodiments a Carbolite® milling medium is preferred. Alternatively, natural sand particles of a suitable particle size can be used.

[0026] Generally speaking, the type of particle size of grinding media to be selected for use in the invention may be dependent on properties such as, for example, the particle size and chemical composition of the feed suspension of material to be ground. Preferably, the particulate grinding medium comprises particles having an average diameter in the range of from approximately 0.5 mm to approximately 6 mm. In one embodiment, the particles have an average diameter of at least approximately 3 mm.

[0027] The grinding medium may comprise particles having a specific gravity of at least approximately 2.5. The grinding medium can comprise particles having a specific gravity of at least about 3 or at least about 4 or at least about 5 or at least about 6.

[0028] The milling medium(s) may (m) be present(s) in an amount of up to approximately 70% by volume of the charge. The milling means may be present in an amount of at least approximately 10% by volume of the charge, for example, at least approximately 20% by volume of the charge or at least approximately 30% by volume of the charge or at least approximately 40% by volume of the cargo or at least approximately 50% by volume of the cargo or at least approximately 60% by volume of the cargo.

[0029] The grinding base may also comprise particulate inorganic material co-processed as a pigment and/or diluent. In this embodiment, the particulate inorganic material is processed with a fibrous substrate comprising cellulose during the preparation of said microfibrillated cellulose. In an advantageous embodiment, microfibrillated cellulose can be obtained by a method comprising microfibrillating a fibrous substrate comprising cellulose in a suitable environment, advantageously an aqueous environment, in the presence of said particulate organic material. In another embodiment, the microfibrillation step comprises milling the fibrous substrate comprising cellulose in the presence of the particulate inorganic material. Grinding can be carried out in a tower mill, a sieve mill, an agitated medium mill or an agitated medium debris. Suitable methods for preparing microfibrillated cellulose in the presence of an inorganic particulate material are described in WO-A-2010/131016, see in particular page 9, line 19 to page 22, line 12, the entire contents of which are incorporated herein as reference.

[0030] In this modality, a means of grinding particulate may be present. As described above, by means of milling is meant a medium other than the particulate inorganic material which is milled together with the fibrous substrate comprising cellulose. The particulate milling means, where present, may be of a type, shape and size as described above in association with the embodiment in which milling is carried out in the absence of particulate inorganic material which can be milled.

[0031] The fibrous substrate comprising cellulose can be derived from any suitable source, such as wood, grasses (eg, sugar cane, bamboo) or rags (eg, textile, cotton, hemp or linen). The cellulose-comprising fibrous substrate may be in the form of a paste (i.e., a suspension of cellulose fibers in water), which may be prepared by any suitable chemical or mechanical treatment or combination thereof. For example, the pulp may be a chemical pulp or a chemothermomechanical pulp or a mechanical pulp or a recycled pulp or paper mill scrap or a stream from a paper mill scrap or a combination thereof. Pulp pulp can be beaten (eg in a Valley blender) and/or otherwise refined (eg processed in a conical or plate refiner) to any predetermined opening, shown in the art as Canadian opening standardized ("Canadian standard freeness (CSF)" in cm3. CSF means a value for the opening or pulp drainage rate measured by the rate at which a pulp suspension can be drained. For example, pulp may have an opening Standard Canadian of approximately 10 cm3 or greater before being microfibrillated. Cellulose pulp may have a CSF of approximately 700 cm3 or less, for example, equal to less than approximately 650 cm3 or equal to or less than approximately 600 cm3 or equal to or less than approximately 550 cm3 or equal to or less than approximately 500 cm3 or equal to or less than approximately 450 cm3 or equal to or less than approximately 400 cm3 equal to u less than approximately 350 cm3 equal to or less than approximately 300 cm3 equal to or less than approximately 250 cm3 equal to or less than approximately 200 cm3 equal to or less than approximately 150 cm3 equal to or less than approximately 100 cm3 equal to or less than approximately 50 cm3. The cellulose pulp may then be dewatered by methods well known in the art, for example the pulp may be filtered through a sieve to obtain a wet sheet comprising at least approximately 10% solids, for example at least approximately 15% solids or at least approximately 20% solids or at least approximately 30% solids or at least approximately 40% solids. The paste can be used in an unrefined state; that is, without being beaten or dehydrated or otherwise refined.

[0032] The fibrous substrate comprising cellulose can be added to a milling vessel or to a homogenizer in a dry state. For example, leftover paper or scrap paper can be added directly to the mill container. The aqueous environment in the grinder vessel will facilitate the formation of a paste.

[0033] Milling can be carried out in one or more stages. For example, a coarse particulate inorganic material may be milled in the mill vessel to a predetermined particle size distribution, after which the fibrous material comprising cellulose is added and milling continued until the desired level of microfibrillation has been obtained. .

[0034] In one embodiment, the mean particle size (d50) of the inorganic particulate material is reduced during the co-milling process. For example, the d50 of the particulate inorganic material can be reduced by at least about 10%, for example, the d50 of the particulate inorganic material can be reduced by at least about 20% or reduced by at least about 30% or reduced by at least approximately 40% or reduced by at least approximately 50% or reduced by at least approximately 60% or reduced by at least approximately 70% or reduced by at least approximately 80% or reduced by at least approximately 90%. For example, an inorganic particulate material that has a d50 of 2.5 µm before grinding and a d50 of 1.5 µm after grinding will have been subjected to a 40% reduction in particle size. In embodiments, the average particle size of the particulate inorganic material is not significantly reduced during the comminution process. By 'not significantly reduced' it is meant that the d50 of the particulate inorganic material is reduced by less than about 10%, for example the d50 of the particulate inorganic material is reduced by less than about 5%.

[0035] The fibrous substrate comprising cellulose can be microfibrillated in the presence of a particulate inorganic material to obtain microfibrillated cellulose that has a d50 in the range of from approximately 5 μm to approximately 500 μm, as measured by laser light scattering. The fibrous substrate comprising cellulose may be microfibrillated in the presence of a particulate inorganic material to obtain microfibrillated cellulose having a d50 equal to or less than approximately 400 μm, for example, equal to or less than approximately 300 μm or equal to or less than approximately 200 μm or equal to or less than approximately 150 μm or equal to or less than approximately 125 μm or equal to or less than approximately 100 μm or equal to or less than approximately 90 μm or equal to or less than approximately 80 μm or equal to or less than approximately 70 μm or equal to or less than approximately 60 μm or equal to or less than approximately 50 μm or equal to or less than approximately 40 μm or equal to or less than approximately 30 μm or equal to or less than approximately 20 μm or equal to or less than approximately 10 μm.

[0036] The fibrous substrate comprising cellulose can be microfibrillated in the presence of an inorganic particulate material to obtain microfibrillated cellulose having a modal fiber particle size in the range of from approximately 0.1-500 µm and a particle size of modal fiber from inorganic particulate material in the range of 0.25-20 µm. The cellulose-comprising fibrous substrate may be microfibrillated in the presence of an inorganic particulate material to obtain microfibrillated cellulose having a modal fiber particle size of at least approximately 0.5 µm, for example, at least approximately 10 µm or of at least approximately 50 μm or at least approximately 100 μm or at least approximately 150 μm or at least approximately 200 μm or at least approximately 300 μm or at least approximately 400 μm.

[0037] The fibrous substrate comprising cellulose can be microfibrillated in the presence of a particulate inorganic material to obtain microfibrillated cellulose having a fiber slope equal to or greater than approximately 10, as measured by Malvern. The fiber slope (ie, the slope of the fiber particle size distribution) is determined by the following formula: Slope = 100 x (d30/d70)

[0038] Microfibrillated cellulose may have a fiber inclination equal to or less than approximately 100. Microfibrillated cellulose may have a fiber inclination equal to or less than approximately 75 or equal to or less than approximately 50 or equal to or less than about 40 or equal to or less than about 30. The microfibrillated cellulose may have a fiber slope of from about 20 to about 50 or from about 25 to about 40 or from about 25 to about 35 or from approximately 30 to approximately 40.

[0039] Grinding is suitably carried out in a grinding vessel, such as in a drum mill (eg stick, ball and autogenous), an agitated mill (eg SAM or IsaMill), a tower mill , a stirred medium debris (SMD) or the feed to be milled is introduced into a milling vessel comprising rotating parallel plates.

The fibrous substrate comprising cellulose and inorganic particulate material may be present in the aqueous environment at an initial solids content of at least approximately 4% by weight, of which at least approximately 2% by weight is fibrous substrate comprising cellulose. The initial solids content can be at least about 10% by weight or at least about 20% by weight or at least about 30% by weight or at least about at least 40% by weight. At least about 5% by weight of the initial solids content may be a fibrous substrate comprising cellulose, for example, at least about 10% or at least about 15% or at least about 20% by weight of the Initial solids content can be fibrous substrate which comprises cellulose.

[0041] When the suspension of material to be milled may be of a relatively high viscosity, a suitable dispersing agent may preferably be added to the suspension prior to milling. The dispersing agent can be, for example, a water-soluble condensed phosphate, polysilicic acid or a salt thereof, or a polyelectrolyte, for example, a water-soluble salt of a polyacrylic acid or a polymethacrylic acid having a weight average molecular in number not greater than 80,000. The amount of dispersing agent used will generally be in the range of from 0.1 to 2.0% by weight, based on the weight of the dry solid inorganic particulate material. The suspension can suitably be milled at a temperature in the range from 4°C to 100°C.

[0042] Other additives that can be included in the microfibrillation step include: carboxymethyl cellulose, amphoteric carboxymethyl cellulose, oxidizing agents, 2, 2, 6, 6-Tetramethylpiperidine-1-oxyl (TEMPO), TEMPO derivatives and enzymes that degrade wood.

[0043] The pH of the suspension of material to be milled may be approximately 7 or greater than approximately 7 (ie, basic), for example, the pH of the suspension may be approximately 8 or approximately 9 or approximately 10 or approximately 11. The pH of the suspension of material to be milled may be less than approximately 7 (i.e. acidic), for example, the pH of the suspension may be approximately 6 or approximately 5 or approximately 4 or approximately 3. The pH of the suspension of material to be ground can be adjusted by adding an appropriate amount of acid or base. Suitable bases include alkali metal hydroxides such as, for example, NaOH. Other suitable bases are sodium carbonate and ammonia. Suitable acids have included inorganic acids such as hydrochloric acid and sulfuric acid or organic acids. An example of an acid is orthophosphoric acid.

[0044] The amount of inorganic particulate material and cellulose pulp in the mixture to be comminuted may vary in a ratio of from approximately 99.5 : 0.5 to approximately 0.5 : 99.5, based on the dry weight of material inorganic particulate and the amount of dry fiber in the pulp, for example a ratio of from approximately 99.5:0.5 to approximately 50:50 based on the dry weight of the inorganic particulate material and the amount of dry fiber in the pulp. For example, the ratio of the amount of inorganic particulate material to dry fiber can be from approximately 99.5:0.5 to approximately 70:30. In one embodiment, the ratio of inorganic particulate material to dry fiber is approximately 80:20 or for example approximately 85:15 or approximately 90:10 or approximately 91:9 or approximately 92:8 or approximately 93 :7 or approximately 94:6 or approximately 95:5 or approximately 96:4 or approximately 97:3 or approximately 98:2 or approximately 99:1. In a preferred embodiment, the weight ratio of inorganic particulate material to dry fiber is approximately 95:5. In another preferred embodiment, the weight ratio of inorganic particulate material to dry fiber is approximately 90:10. In another preferred embodiment, the weight ratio of inorganic particulate material to dry fiber is approximately 85:15. In another preferred embodiment, the weight ratio of inorganic particulate material to dry fiber is approximately 80:20.

[0045] The total energy input into a typical milling process to obtain the desired composition of the aqueous suspension may typically be between approximately 100 and 1500 kWht-1 based on the total dry weight of the inorganic particulate load. The total energy input may be less than approximately 1000 kWht-1, for example, less than approximately 800 kWht-1, less than approximately 600 kWht-1, less than approximately 500 kWht-1, less than approximately 400 kWht-1, less than approximately 300 kWht-1 or less than approximately 200 kWht-1. As will be evident, the total energy input per ton of dry fiber in the fibrous substrate comprising cellulose will be less than approximately 10,000 kWht-1, for example, less than approximately 9000 kWht-1 or less than approximately 8000 kWht-1 or less than approximately 7000 kWht-1 or less than approximately 6000 kWht-1 or less than approximately 5000 kWht-1, eg less than approximately 4000 kWht-1, less than approximately 3000 kWht-1, less than approximately 2000 kWht-1, less than approximately 1500 kWht-1, less than approximately 1200 kWht-1, less than approximately 1000 kWht-1, or less than approximately 800 kWht-1. The total energy input varies depending on the amount of dry fiber in the fibrous substrate that is microfibrillated and optionally the speed of grinding and the duration of grinding.

[0046] Alternatively or additionally, microfibrillation of the fibrous substrate comprising cellulose can be carried out under humid conditions in the presence of the particulate inorganic material by a method in which the mixture of cellulose pulp and particulate inorganic material is pressurized (e.g., up to a pressure of approximately 500 KpaKpa) and then passed to a zone of lower pressure. The rate at which the mixture is passed to the low pressure zone is high enough and the pressure in the low pressure zone is low enough to cause microfibrillation of the cellulose fibers. For example, a pressure drop can be effected by forcing the mixture through an annular opening which has a reduced orifice with a much larger exit orifice. The drastic decrease in pressure as a mixture accelerates to a larger volume (ie, a zone of lower pressure) induces cavitation which causes microfibrillation. In one embodiment, microfibrillation of the fibrous substrate comprising cellulose can be carried out in a homogenizer under humid conditions in the presence of the particulate inorganic material. In the homogenizer, the mixture of cellulose and inorganic particulate material from the pulp is pressurized (eg to a pressure of approximately 500 Kpa) and forced through a small nozzle or orifice. The mixture may be pressurized to a pressure of from approximately 100 to approximately 1000 Kpa, for example, to a pressure equal to or greater than 300 Kpa or equal to or greater than approximately 500 or equal to or greater than approximately 200 Kpa or equal or greater than approximately 700 Kpa. Homogenization subjects the fibers to high shear forces such that the pressurized cellulose pulp comes out of the nozzle or orifice, cavitation causes microfibrillation of the cellulose fibers in the pulp. Additional water can be added to improve the flowability of the suspension through the homogenizer. The resulting aqueous suspension comprising the microfibrillated cellulose and inorganic particulate material can be fed back into the homogenizer inlet during multiple passes through the homogenizer. The inorganic particulate material can be a naturally flat mineral such as kaolin. As such, homogenization not only facilitates microfibrillation of the cellulose pulp, but also facilitates delamination of the flat particulate material.

[0047] It is understood that a flat particulate material, such as kaolin, has a shape factor of at least approximately 10, for example, at least approximately 15 or at least approximately 20 or at least approximately 30 or at least minus about 40 or at least about 50 or at least about 60 or at least about 70 or at least about 80 or at least about 90 or at least about 100, shape factor, as used in this case, is a measure of the ratio of particle diameter to particle thickness for a population of particles of varying size and shape as measured using the methods, apparatus, and equations of electrical conductivity described in US Pat. 5,576,617, which is incorporated herein by reference.

[0048] A suspension of a flat particulate inorganic material, such as kaolin, can be treated in the homogenizer to a predetermined particle size distribution in the absence of the cellulose-comprising fibrous substrate, after the cellulose-comprising fibrous material is added to the aqueous suspension of inorganic particulate material and the combined suspension is processed in the homogeniser as described above. The homogenization process continues, including one or more passes through the homogenizer, after the desired level of microfibrillation has been achieved. Similarly, the flat particulate inorganic material can be treated in a grinder to a predetermined particle size distribution and then blended with the fibrous material comprising cellulose followed by processing in the homogenizer. An example of a homogenizer is a Manton Gaulin homogenizer (APV).

[0049] After the microfibrillation step has been carried out, the aqueous suspension comprising the microfibrillated cellulose and the particulate inorganic material can be sieved to remove the fiber above a certain size and to remove any grinding media. For example, the suspension can be sieved using a sieve having a selected nominal aperture size to remove fibers that do not pass through the sieve. Nominal opening size means the nominal central separation of opposite sides of a square opening or the nominal diameter of a round opening. The sieve may be a BSS sieve (according to BS 1796) having a nominal opening size of 150 µm, for example a nominal opening size of 125 µm or 106 µm or 90 µm or 74 µm or 63 µm or 53 µm, 45 µm or 38 µm. In one embodiment, the aqueous suspension is sieved using a BSS sieve that has a nominal aperture of 125 µm. The aqueous suspension can then optionally be dehydrated.

[0050] In certain embodiments, microfibrillated cellulose is obtained by milling the fibrous substrate comprising cellulose in the presence of a milling medium and optionally in the presence of a particulate inorganic material, to obtain said microfibrillated cellulose, for example, cellulose microfibrillated cellulose that has a fiber slope equal to or greater than approximately 10, as measured by Malvern, as described above, or from approximately 20 to approximately 50, and then the microfibrillated cellulose (which optionally includes the co-processed particulate inorganic material) is further treated to a homogenizer under humid conditions. In the homogenizer, the microfibrillated cellulose is pressurized (eg to a pressure of approximately 500 Kpa) and forced through a small nozzle or orifice. The mixture may be pressurized to a pressure of from approximately 100 to approximately 1000 KPa, for example, to a pressure equal to or greater than 300 KPa or equal to or greater than approximately 500 or equal to or greater than approximately 200 KPa or equal to or greater than approximately 700 Kpa. Additional water can be added to improve the flowability of the suspension through the homogenizer. The resulting aqueous suspension comprising microfibrillated cellulose and optional particulate inorganic material can be fed back to the homogenizer inlet for multiple passes through the homogenizer.

[0051] For use in a milling base of the present invention, the co-processed microfibrillated cellulose and inorganic particulate material may be supplied in the form of an aqueous suspension or a wet pressed cake.

[0052] In embodiments in which microfibrillation is conducted in the absence of particulate inorganic material that can be milled, the fibrous substrate comprising cellulose can be microfibrillated to obtain microfibrillated cellulose that has a d50 in the range of from approximately 5 μm to approximately 500 μm , as measured by laser light scattering. The fibrous substrate comprising cellulose may be microfibrillated to obtain microfibrillated cellulose having a d50 equal to or less than approximately 400 μm, for example, equal to or less than approximately 300 μm or equal to or less than approximately 200 μm, or equal to or less than approximately 150 μm or equal to or less than approximately 125 μm or equal to or less than approximately 100 μm or equal to or less than approximately 90 μm or equal to or less than approximately 80 μm or equal to or less than approximately 70 μm or equal to or less than approximately 60 μm or equal to or less than approximately 50 μm or equal to or less than approximately 40 μm or equal to or less than approximately 30 μm or equal to or less than approximately 20 µm or equal to or less than approximately 10 µm.

[0053] The fibrous substrate comprising cellulose can be microfibrillated to obtain microfibrillated cellulose having a modal fiber particle size in the range of from approximately 0.1 - 500 µm. The cellulose-comprising fibrous substrate may be microfibrillated to obtain microfibrillated cellulose having a modal fiber particle size of at least approximately 0.5 µm, for example, at least approximately 10 µm or at least approximately 50 µm, or of at least approximately 100 μm or at least approximately 150 μm or at least approximately 200 μm or at least approximately 300 μm or at least approximately 400 μm.

[0054] The fibrous substrate comprising cellulose can be microfibrillated to obtain microfibrillated cellulose having a fiber slope equal to or greater than approximately 10, as measured by Malvern. The fiber slope (ie, the slope of the fiber particle size distribution) is determined by the following formula: Slope = 100 x (d30/d70)

[0055] Microfibrillated cellulose may have a fiber inclination equal to or less than approximately 100. Microfibrillated cellulose may have a fiber inclination equal to or less than approximately 75 or equal to or less than approximately 50 or equal to or less than about 40 or equal to or less than about 30. The microfibrillated cellulose may have a fiber slant from about 20 to about 50 or from about 25 to about 40 or from about 25 to about 35 or from approximately 30 to approximately 40.

[0056] As noted before, grinding is carried out in the presence of a grinding medium. In one embodiment, the milling medium is a coarse medium comprising particles having an average diameter in the range of from approximately 1 mm to approximately 6 mm, for example, approximately 2 mm or approximately 3 mm or approximately 4 mm or approximately 5 mm .

[0057] In another, the milling medium has a specific gravity of at least about 2.5, for example, at least about 3, or at least about 3.5, or at least about 4.0, or at least approximately 4.5 or at least approximately 5.0 or at least approximately 5.5 or at least approximately 6.0.

[0058] As described above, the milling means (or means) may (m) be in an amount of up to approximately 70% by volume of the charge. The milling means may be present in an amount of at least approximately 10% by volume of the charge, for example, at least approximately 20% by volume of the charge or at least approximately 30% by volume of the charge or at least approximately 40% by volume of the cargo or at least approximately 50% by volume of the cargo or at least approximately 60% by volume of the cargo.

[0059] In one modality, the grinding medium is present in an amount of approximately 50% by volume of the charge.

[0060] By 'load' it is understood the composition that is the feed introduced in the container of the grinder. The filler includes water, grinding media, the fibrous substrate comprising cellulose and any other optional additives (other than as described in this case).

[0061] The fibrous substrate comprising cellulose may be present in an aqueous environment at an initial solids content of at least approximately 1% by weight. The cellulose-comprising fibrous substrate may be present in the aqueous environment at an initial solids content of at least about 2% by weight, for example at least about 3% by weight or at least about at least 4% by weight . Typically the initial solids content will not be greater than approximately 10% by weight.

[0062] For use in a milling base of the present invention, microfibrillated cellulose prepared in the absence of particulate inorganic material may be provided which may be milled in the form of an aqueous suspension or a wet pressed cake. - co-processed inorganic particulate material

[0063] According to the present invention, the co-processed inorganic particulate material can be included in the base for grinding and the paint composition as the main pigment or diluent pigment (as described further below).

[0064] The inorganic particulate material may, for example, be an alkaline earth metal carbonate or sulphate, such as calcium carbonate, magnesium carbonate, dolomite, gypsum, a kandiite clay, such as kaolin, halloysite or ball clay, an anhydrous (calcined) kandite clay such as metakaolin or fully calcined kaolin, talc, mica, perlite or diatomaceous earth or magnesium hydroxide or aluminum trihydrate or combinations thereof. The inorganic particulate material can also be a conventional mineral pigment such as titanium dioxide, calcium sulphate and iron oxide, preferably titanium dioxide.

[0065] In one embodiment, the inorganic particulate material is an alkaline earth metal carbonate, eg calcium carbonate. The inorganic particulate material can be ground calcium carbonate (GCC) or precipitated calcium carbonate (PCC) or a mixture of GCC and PCC.

[0066] In another modality, the inorganic particulate material is a naturally flat mineral, eg kaolin. The inorganic particulate material can be a mixture of kaolin and calcium carbonate, for example a mixture of kaolin and GCC or a mixture of kaolin and PCC or a mixture of kaolin, GCC and PCC.

[0067] The particulate calcium carbonate used in the present invention can be obtained from a natural source by milling. Ground calcium carbonate (GCC) is typically obtained by grinding and then grinding a mineral source such as chalk, marble or limestone, which can be followed by a particle size classification step to obtain a product that has the degree of openness desired. Other techniques such as bleaching, flotation and magnetic separation can also be used to obtain a product that has the desired degree of openness and/or color. The solid particulate material can be milled autogenously, i.e., by friction between the solid material particles themselves, or alternatively in the presence of a particulate milling means comprising particles of a material other than the calcium carbonate to be milled. These processes can be carried out with or without the presence of a dispersant and biocides, which can be added at any stage of the process.

[0068] Precipitated calcium carbonate (PCC) can be used as the source of particulate calcium carbonate in the present invention and can be produced by any of the known methods available in the art. TAPPI Monograph Series No 30, "Paper Coating Pigments", pages 34-35 describes the three main commercial processes for preparing precipitated calcium carbonate which is suitable for use in preparing products for use in the paper industry, but can also be used in the practice of the present invention. In all three processes, a calcium carbonate feed material, such as limestone, is first calcined to produce quicklime and the quicklime is then quenched in water to provide calcium hydroxide or milk of lime. In the first process, lime milk is directly carbonated with carbon dioxide gas. This process has the advantage that no by-product is formed and it is relatively easy to control the properties and purity of the calcium carbonate product. In the second process, the milk of lime is brought into contact with a barilha to produce, by double decomposition, a precipitate of calcium carbonate and a solution of sodium hydroxide. Sodium hydroxide can be substantially completely separated from calcium carbonate if this process is used commercially. In the third major commercial process the lime milk is first contacted with ammonium chloride to provide a solution of calcium chloride and ammonia gas. The calcium chloride solution is then contacted with the clay to produce by double decomposition precipitated calcium carbonate and a sodium chloride solution. Crystals can be produced in a variety of different shapes and sizes, depending on the specific reaction process that is used. The three main forms of PCC crystals are aragonite, rhombohedral and scalenehedral, all of which are suitable for use in the present invention, including mixtures thereof.

[0069] Wet-state grinding of calcium carbonate involves the formation of an aqueous suspension of the calcium carbonate which can then be ground, optionally in the presence of a suitable dispersing agent. Reference may be made, for example, to EP-A-614948 (the contents of which are hereby incorporated by reference in their entirety) for further information regarding the wet grinding of calcium carbonate.

[0070] The kaolin clay used in this invention may be a processed material derived from a natural source, namely raw natural kaolin mineral clay. Processed kaolin can typically contain at least approximately 50% by weight of kaolinite. For example, most commercially processed kaolin clays contain greater than approximately 75% by weight of kaolinite and may contain greater than approximately 90%, in some cases greater than approximately 95% by weight of kaolinite.

The kaolin clay used in the present invention can be prepared starting from the raw mineral kaolin by one or more other processes that are well known to those skilled in the art, for example, by known refining or beneficiation steps.

[0072] For example, clay mineral can be bleached with a reducing bleaching agent such as sodium hyposulfite. If sodium hyposulfite is used, the bleached clay mineral may optionally be dehydrated and optionally washed and optionally dehydrated again, after the sodium hyposulfite bleaching step.

[0073] Clay mineral can be treated to remove impurities, for example, by flocculation, flotation or magnetic separation techniques well known in the art. Alternatively the clay mineral used in the first aspect of the invention may be untreated as a solid or as an aqueous suspension.

[0074] The process for preparing the particulate kaolin clay used in the present invention may also include one or more steps of spraying, e.g. crushing or milling. Lightly spraying a coarse kaolin is used to provide adequate delamination of the kaolin. Spraying can be accomplished by using small beads or granules of a plastic (eg nylon), sand or ceramic grinding aid or grinding aid. Coarse kaolin can be refined to remove impurities and improve physical properties using well-known procedures. Kaolin clay can be treated by a known particle classification procedure, for example sieving and centrifugation (or both), to obtain particles having a desired d50 value or particle size distribution.

[0075] The particle size distribution of the inorganic material particulates will be that which is suitable for use in paint. Suitable particle sizes are described below in association with the main pigment and the extender pigment.

[0076] In one embodiment, the inorganic particulate material used during the microfibrillation step may have a particle size distribution in which at least approximately 10% by weight of the particles have an e.s.d. less than 2 µm, for example, at least about 20% by weight or at least about 30% by weight or at least about 40% by weight or at least about 50% by weight or at least about 60 % by weight or at least approximately 70% by weight or at least approximately 80% by weight or at least approximately 90% by weight or at least approximately 95% by weight or approximately 100% of the particles have an esd. less than 2 µm.

[0077] The amount of inorganic particulate material co-processed in the ink composition of the present invention can range from approximately 0.1 to approximately 30% by weight, based on the total weight of the ink composition. In embodiments, the amount of inorganic particulate material co-processed in the ink composition can be from approximately 0.2 to approximately 20% by weight, e.g., from approximately 0.2 to approximately 10%, e.g., from approximately 0.2 to approximately 5% by weight, for example, from approximately 0.3 to approximately 5% by weight, for example, from approximately 0.4 to approximately 4% by weight, for example, from approximately 0.4 to approximately 3% by weight or from approximately 0.4 to approximately 2% by weight.

[0078] Advantageously, the co-processed particulate inorganic material is suitable for use as a main pigment or thinner pigment, which means the amount of main pigment and/or thinner pigment that would otherwise have been separately added to a base for grinding can be reduced. In one embodiment, the co-processed inorganic particulate constitutes all of the main pigment and/or extender pigment contained in the grinding base and/or paint composition of the present invention. - main pigment and thinner pigment

[0079] In another modality, the base for grinding comprises main pigment and/or extender pigment, without being the co-processed particulate inorganic material described above.

[0080] A main pigment is one that provides the main primary coloration of an ink, whether white or a shade of color. The term includes insoluble, finely ground, natural or synthetic, inorganic or organic dispersed particles, when dispersed in a liquid vehicle, i.e. solvent, can provide, in addition to color, many of the desired properties of paint, such as: opacity, hardness , durability and corrosion resistance. Diluent pigments are the filler used in paints. Diluent pigments generally do not hide in general as well as major pigments and their presence can affect the overall characteristics and performance of a paint. Main pigment is generally more expensive than thinner pigment.

[0081] Thus, for example purposes, the grinding base may comprise titanium dioxide as the main pigment, optionally co-processed calcium carbonate as the thinner pigment and other particulate inorganic material as the thinner pigment, such as calcium carbonate. calcium, kaolin and/or talc, which are not derived from the processes described in this case for preparing microfibrillated cellulose.

Suitable main pigments include, but are not limited to, titanium dioxide, carbon black, calcium sulfate, iron oxide and the copper phthale blue complex. Other main pigments suitable for providing the color will be readily apparent to persons skilled in the art.

[0083] Diluent pigments include, but are not limited to, an alkaline earth metal carbonate or sulfate, such as calcium carbonate, magnesium carbonate, dolomite, gypsum, a hydrated kandita clay such as kaolin, halloysite, or ball clay , an anhydrous (calcined) kandita clay such as metakaolin or fully calcined kaolin, talc, mica, perlite, feldspars, nepheline syenite, wollastonite, diatomaceous earth, barite, glass and natural or synthetic silica or silicates. The grinding base and paint composition may include one or more or a mixture of the above-mentioned diluent pigments.

[0084] For paint applications where a lower degree of whiteness and/or lower opacity can be tolerated or even desired, a thinner pigment such as, for example, calcium carbonate, can be used as a main pigment .

[0085] In one embodiment, the average particle size (d50) of the main pigment and/or diluent pigment (and the co-processed inorganic particulate material described above) can be from approximately 0.1 µm to approximately 20 µm, as determined by Sedigraph. For example, the d50 can be from approximately 0.2 µm to approximately 15 µm or from approximately 0.3 µm to approximately 12 µm or from approximately 0.4 µm to approximately 10 µm or from approximately 0.6 μm to approximately 10 μm or from approximately 0.8 μm to approximately 10 μm or from approximately 1 μm to approximately 10 μm or from approximately 1.5 μm to approximately 10 μm or from approximately 2 μm to approximately 10 μm or from approximately 2.5 to approximately 10 µm. The d50 of the main pigment and/or diluent pigment can be up to approximately 9 µm, for example up to approximately 8 µm or up to approximately 7 µm or up to approximately 6 µm or up to approximately 5 µm or up to approximately 4 µm or up to approximately 3 µm or up to approximately 2 µm.

[0086] In one embodiment, the main pigment is titanium dioxide, eg TiO2 rutile or TiO2 anatase. Titanium oxide can be prepared starting from the mineral ilmenite or the rutile ore. The titanium oxide particles can be coated, for example, with alumina, silica and/or zirconia. Advantageously, titanium oxide has an oil absorption in the range of from approximately 10 to approximately 30 cm3/100 g of pigment, for example from approximately 20 cm3/100 g of pigment, as determined in accordance with ISO 787/11 (blade method for painting). Advantageously, the grinding base comprises one or more of the main pigments mentioned above, advantageously titanium dioxide and one or more or advantageously all of kaolin, calcium carbonate and talc as the extender pigment.

[0087] Kaolin may be a hydrated kaolin, it may have a d50 of from approximately 0.2 μm to approximately 10 μm, for example, from approximately 0.3 μm to approximately 5 μm or from approximately 0.4 μm to approximately approximately 5 µm or from approximately 0.4 µm to approximately 3.5 µm as determined by Sedigraph. Kaolin can have an oil absorption (ISO 787/5) of from approximately 30 to approximately 50 g of oil/100 g of pigment.

[0088] Calcium carbonate may have a d50 of from approximately 0.5 μm to 12 μm, for example, from approximately 0.8 μm to approximately 10 μm, as determined by Sedigraph. Calcium carbonate can have an oil absorption of from approximately 15 to approximately 30 (ISO 787/5). In certain embodiments, the grinding base or paint composition can comprise a mixture of coarse and fine calcium carbonate. For example, the mixture of calcium carbonate having a d50 of from approximately 0.5 to approximately 4 µm, for example, from approximately 1.0 to approximately 3 µm, and calcium carbonate which has a d50 of from approximately 5 to approximately approximately 8 µm, for example from approximately 5.5 to approximately 7 µm.

Talc may have a d50 of from approximately 1 µm to approximately 15 µm, for example from approximately 1 to approximately 12 µm or from approximately 1 to approximately 10 µm or from approximately 1 to approximately 9 µm or from approximately 2 to approximately 12 µm or from approximately 5 to approximately 12 µm as determined by Sedigraph. Talc can have an oil absorption of from approximately 30 to approximately 80 (ISO 787/5). In certain embodiments, the amount of talc in the paint composition is from approximately 0.1 to approximately 10% by weight, for example, from approximately 0.5 to approximately 8% by weight or from approximately 2 to approximately 8% by weight. weight or from approximately 4% by weight. In certain embodiments, for example embodiments in which the paint comprises a mixture of fine and coarse calcium carbonate as described above, the amount of talc in the paint composition is from approximately 0.1 to approximately 4% by weight. , for example, from approximately 1.0 to approximately 3% by weight.

The amount of main pigment in the paint composition of the invention formulated from a grinding base can be from approximately 1% to approximately 50% by weight, based on the total weight of the paint composition. In one embodiment, the amount of main pigment is from approximately 5% to 40% by weight or from approximately 5% to approximately 30% by weight or from approximately 5% to approximately 20% by weight or from approximately 5% to approximately 15% by weight or from approximately 6% to approximately 12% by weight or from approximately 8% to approximately 12% by weight, based on the total weight of the ink composition.

[0091] The total amount of pigment diluent in the paint composition of the invention formulated from a grinding base can be from approximately 1% to approximately 60% by weight, based on the total weight of the paint composition. In one embodiment, the amount of pigment diluent is from approximately 1% to approximately 50% by weight or from approximately 5% to approximately 40% by weight or from approximately 10% to approximately 40% by weight or from approximately 15% to approximately 40% by weight or from approximately 15% to approximately 35% by weight or from approximately 20% to approximately 35% by weight or from approximately 25% to approximately 35% by weight, based on the total weight of the paint composition.

[0092] The total amount of main pigment, pigment extender and inorganic particulate material co-processed in the paint composition of the invention formulated with the grinding base can be from approximately 2% to approximately 80% by weight, based on the total weight of the composition of ink. In one embodiment, the amount of pigment diluent is from approximately 5% to 70% by weight or from approximately 10% to approximately 70% by weight or from approximately 15% to approximately 70% by weight or from approximately 15 % to approximately 60% by weight or from approximately 20% to approximately 50% by weight or from approximately 25% to approximately 45% by weight or from approximately 30% to approximately 60% by weight or from approximately 40% to approximately approximately 50% by weight, based on the total weight of the ink composition. - rheology modifiers

[0093] The grinding base and the ink composition can comprise a rheology modifier other than the said microfibrillated cellulose. Said other rheology modifier may be a cellulose-derived rheology modifier, for example, hydroxymethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, hydroxypropylmethyl cellulose, carboxymethyl cellulose or a mixture thereof. In another embodiment, the milling base and paint composition (optionally formulated starting from said milling base), is free of cellulose-derived rheology modifier other than said microfibrillated cellulose. Thus, in an embodiment the weight ratio of said microfibrillated cellulose to cellulose-derived rheology modifier other than said microfibrillated cellulose is from approximately 1 to approximately 1:5, for example, from approximately 1000:1 to approximately 1 :4 or from approximately 100:1 to approximately 1:4 or from approximately 10:1 to approximately 1:4 or from approximately 1000:1 to approximately 1:3 or from approximately 1000:1 to approximately 1 :2 or from approximately 1000:1 to approximately 1:1 or from approximately 1000:1 to approximately 3:2 or from approximately 1000:1 to approximately 3:1 or from approximately 1000:1 to approximately 4 :1 or from approximately 1000:1 to approximately 5:1. In other embodiments, the weight ratio of said microfibrillated cellulose to cellulose-derived rheology modifier other than said microfibrillated cellulose is approximately 1:5 or approximately 1:4 or approximately 1:3 or approximately 1:2 or of about 1:1 or about 2:1 or about 3:2 or about 3:1 or about 4:1 or about 5:1 or about 6:1 or about 7:1 or about 8:1 or about 9:1 or about 10:1 or about 20:1 or about 50:1 or about 100:1 or about 1000:1.

[0094] In another embodiment, the grinding base or ink composition comprises rheology modifier not derived from cellulose. Such rheology modifiers include one or more of associative acrylic thickeners, polyacrylates, emulsion copolymers, dicyanamide, triols, polyoxyethylene ether, urea, sulfated castor oil, polyvinyl pyrrolidone, sodium alginate, xanthan gum, silicate sodium and acrylic acid copolymers. Such non-cellulose-derived rheology modifier may be present in an amount of up to approximately 5% by weight based on the total weight of the ink composition, for example, from approximately 0.1 to approximately 4% by weight or from from approximately from approximately 0.2 to approximately 3% by weight or from approximately 0.2 to approximately 2% by weight based on the total weight of the ink composition.

[0095] In one embodiment, the milling base or paint composition (optionally formulated starting from said milling base), does not contain microfibrillated cellulose that is produced from a partially enzymatic treatment of cellulose fibers. paint composition

[0096] According to the second aspect, the ink composition comprises microfibrillated cellulose as described in this case, binder and solvent, wherein the microfibrillated cellulose is present in an amount ranging from 0.1% to 10% by weight based in the total weight of the paint composition.

[0097] In one embodiment, the ink composition also comprises co-processed particulate inorganic material, as described in this case, as the main pigment and/or extender pigment, wherein said particulate organic material is co-processed with a fibrous substrate comprising cellulose during the preparing said microfibrillated cellulose. In another embodiment, the ink composition also comprises main pigment and/or diluent pigment as described in this case, other than the co-processed particulate inorganic material.

[0098] In embodiment, microfibrillated cellulose can be obtained by the methods described in this case which comprises microfibrillation of a fibrous substrate comprising cellulose in an aqueous environment by milling in the presence of a milling medium that needs to be removed after milling is completed , in which milling is carried out in the absence of particulate inorganic material that can be milled.

[0099] In one embodiment, microfibrillated cellulose can be obtained by the methods described in this case which comprises microfibrillation of a fibrous substrate comprising cellulose in an aqueous environment in the presence of said particulate organic material. The microfibrillation step may comprise milling the fibrous substrate comprising cellulose in the presence of the particulate inorganic material.

[00100] In one embodiment, the ink composition is formulated starting from a base for grinding the first aspect of the invention and embodiments thereof.

[00101] The paint can be formulated as a decorative paint, which includes matte and glossy paints, such as an industrial paint, including as protective paints and paints for sanitation and the like and other paints such as identification paints, for example, for signage and similar. Advantageously, the paint is a water-based paint, for example a water-based decorative paint, for example a water-based matte decorative paint.

[00102] A solvent is any substance that can act as a vehicle for the pigment and for the binder. Once the substrate is painted, the solvent evaporates by drying and/or curing and leaves behind a film of dry paint on the painted substrate. In one embodiment, the solvent comprises water and optional dispersing chemicals. Organic solvents include mineral solvents, for example, white solvent, petroleum distillate, esters, glycol ethers and the like.

[00103] The amount of solvent in the paint composition will vary depending on the particular paint form and its intended use. In one embodiment, the amount of solvent is present in an amount of from approximately 5% to approximately 90% by weight, based on the total weight of the paint composition. For example, the amount of solvent can be from approximately 10% to approximately 90% by weight or from approximately 15% to approximately 90% by weight or from approximately 20% to approximately 90% by weight or from approximately 25% to approximately 90% by weight or from approximately 30% to approximately 90% by weight or from approximately 35% to approximately 90% by weight or from approximately 40% to approximately 90% by weight, from approximately 10% to approximately 80% by weight, from approximately 20% to approximately 80% by weight or from approximately 30% to approximately 80% by weight or from approximately 30% to approximately 70% by weight or from approximately 30% to approximately 60% by weight or from approximately 40% to approximately 60% by weight or from approximately 5% to approximately 80% by weight or from approximately 5% to approximately approximately 70% by weight or from approximately 5% to approximately 60% by weight or from approximately 5% or from approximately 50% by weight or from approximately 5% or from approximately 40% by weight or from approximately 5% or from approximately 30% by weight or from approximately 5% or from approximately 25% by weight or from approximately 5% or from approximately 20% by weight or from approximately 5% or from approximately 15% by weight or from approximately 10% or from approximately 30% by weight or from approximately 10 to approximately 25% by weight or from approximately 10 to approximately 20% by weight, based on the total weight of the ink composition.

[00104] Binders are components for paint film formation, which provide adhesion and binding of pigments. Thus, the binder is any suitable material that is capable of binding the pigments together and providing adhesion to the substrate that is painted with the ink. The binder can be a natural and/or synthetic resin, such as, for example, latex based binders such as acrylic and/or vinyl based polymers and copolymers, polyurethanes, polyesters, melamine resins, epoxies and /or oils and other monomeric species. In one embodiment, the binder comprises or consists of 100% acrylic latex or polyvinyl acetate (PVA) latex. For oil-based paints, suitable binders include linseed oil, tung oil or alkyd resins.

[00105] The amount of binder in the ink composition will vary depending on the particular ink form and its intended use. In one embodiment, the amount of binder is present in an amount of from approximately 5% to approximately 30% by weight, based on the total weight of the ink composition. For example, the amount of solvent can be from approximately 5% to approximately 25% by weight or from approximately 5% to approximately 20% by weight or from approximately 5% to approximately 15% by weight or from approximately 10% to approximately approximately 30% by weight or from approximately 10 to approximately 25% by weight or from approximately 10 to approximately 20% by weight, based on the total weight of the ink composition.

[00106] The amount of co-processed inorganic particulate material (when present), main pigment and extender pigment (when present) in the paint composition is described above. Other optional additives

[00107] The grinding base and paint composition can include at least one other additive chosen from conventional additives, such as, for example, pigments other than those described in this case, active surfactant, thickener, defoamer or defoamer or defoamer, wetting agent, dispersant, biocide, pH adjusting agent, antifreeze co-solvent and coalescent, as well as other functional additives. These additives may be included in any suitable amount, which will vary depending on the ink composition and the relative amounts of pigment, solvent and binder. These amounts can easily be determined by a person skilled in the art. Generally speaking, these additives can be included, on an individual basis, in the paint in an amount of up to approximately 1% by weight, based on the total weight of the fully formulated paint. The co-solvent may be present in an amount of up to approximately 5% by weight based on the total weight of the fully formulated ink composition, for example, up to approximately 4% by weight or up to approximately 3% by weight or up to approximately 2% by weight.

Suitable dispersants include, for example, polyelectrolytes such as polyacrylates and copolymers containing polyacrylate species, especially polyacrylate salts (eg sodium and aluminum optionally with a group II metal salt), h and - sodium xametaphosphates, nonionic polyol, polyphosphoric acid, condensed sodium phosphate, nonionic surfactants, alkanolamine and other reagents commonly used for this function. The dispersant can, for example, be selected from conventional dispersing materials commonly used in processing and grinding particulate inorganic material. Such dispersants will be well recognized by those skilled in the art. They are generally water-soluble salts capable of providing anionic species which in their effective amounts can be adsorbed on the surface of the inorganic particles and thereby inhibit the aggregation of the particles. Unsolvated salts suitably include alkali metal cations such as sodium. Solvation can in some cases be aided by making the aqueous suspension slightly alkaline. Examples of suitable dispersants include: water-soluble condensed phosphates, for example polymetaphosphate salts [general form of sodium salts: (NaPO3)x] such as tetrasodium metaphosphate or so-called "sodium hexametametaphosphate" (sodium salt Graham); water-soluble salts of polysilicic acids; polyelectrolytes; salts of homopolymers or copolymers of acrylic acid or methacrylic acid or salts of polymers of other acrylic acid derivatives, suitably having a weight average molecular weight of less than approximately 20,000.

[00109] Suitable defoamers and defoamers include, for example, surfactant blends, tributyl phosphate, polyoxyethylene fatty esters plus fatty alcohols, fatty acid soaps, silicone emulsions and other compositions containing silicone, waxes and inorganic particulates in mineral oil, blends of emulsified hydrocarbons and other compounds marketed to perform this function.

[00110] Suitable biocides include, for example, oxidizing biocides such as chlorine gas, chlorine dioxide gas, sodium hypochlorite, sodium hypobromite, hydrogen, peroxide, peracetic oxide, ammonium bromide / sodium hypochlorite or non-oxidizing biocides such as GLUT (Glutaraldehyde, CAS No. 90045-36-6), ISO (CIT/MIT) (Isothiazolinone, CAS No. 55956-84-9 & 96118-96-6), ISO (BIT/MIT) ( Isothiazolinone), ISO (BIT) (Isothiazolinone, CAS No. 2634-33-5), DBN-PA, BNPD (Bronopol), NaOPP, CARBAMATO, TIONA (Dazomet), EDDM - dimethanol (O-formal), HT - Triazine (N-formal), THPS - tetrakis (O-formal), TMAD - diurea (N-formal), metaborate, sodium dodecylbenzene sulfonate, thiocyanate, organo-sulfur, sodium benzoate and other compounds marketed for this function, by example, the range of biocidal polymers marketed by Nalco.

[00111] The ink composition can also include dye. The distinction between powders that are pigments and those that are dyes is generally considered to lie on the basis of solubility: the pigments being insoluble and dispersed in the material, the dyes being soluble or in solution when used. ink properties

[00112] The present inventors have unexpectedly discovered that microfibrillated cellulose, optionally co-processed in the presence of a particular inorganic material, can be used as a rheology modifier in a paint composition in addition to or in (partial) replacement of conventional rheology modifiers such as, for example, hydroxyethyl cellulose and the like, while maintaining or even improving the physical/mechanical, optical and post-application properties of the paint product.

[00113] In embodiments, the use of microfibrillated cellulose, optionally co-processed in the presence of a particular inorganic material, in addition to or in partial or total replacement of conventional cellulose-derived rheology modifiers, such as, for example, hydroxyethyl cellulose and the like , maintains the viscosity of the paint (as determined in accordance with ISO 2884-1) at high shear speed (1/sec), eg at a shear rate of at least approximately 100, but increases significantly the viscosity of the paint at a low shear rate, for example a shear rate of no more than approximately 10. This can have the effect of improving the stability and drip resistance of the paint while remaining easy to apply, for for example, by brush or cylinder). Furthermore, conventional cellulose-derived rheology modifiers such as hydroxyethyl cellulose and the like are relatively more costly to produce than the microfibrillated cellulose described in this case. Thereby, cost savings can be achieved by using a microfibrillated cellulose described in this case in partial or total replacement of conventional cellulose derivatives such as hydroxyethyl cellulose and the like.

[00114] According to some embodiments, the dry ink film produced starting from the ink examples described in this case may exhibit desirable optical properties. For example, in some embodiments, the use of microfibrillated cellulose, optionally co-processed in the presence of a particular inorganic material, in partial or total replacement of conventional cellulose derivative rheology modifiers, such as, for example, hydroxyethyl cellulose and similar, can improve one or more of the opacity (contrast ratio) of the dry film (determined in accordance with ISO 6504-1, ISO 6504-3 or ISO 2814) and the wet scratch resistance of the dry film (determined in accordance with ISO 11998). Furthermore, the use of microfibrillated cellulose, optionally co-processed in the presence of a particular inorganic material, in partial or total replacement of conventional cellulose derivative rheology modifiers, such as, for example, hydroxyethyl cellulose and the like, can provide a reduction significant in 85° gloss (determined in accordance with ISO 2813), which is important for a matte ink of this type.

[00115] In some embodiments, the dry paint film obtained from an ink composition of the invention has an 85° gloss less than about 7.0, for example, less than about 6.5 or less than about 6 .0 or less than approximately 5.5 or less than approximately 5.0.

[00116] In other embodiments, the dry ink film obtained from an ink composition of the invention has a wet scratch resistance of no more than approximately 45 µm, for example, no more than approximately 40 µm or no more than about 35 µm or not more than about 30.

[00117] In other embodiments, the dry paint film obtained from an paint composition has a Burnish (at 85°) less than about 5.8, for example less than about 5.5 or less than about 5 .0 or less than approximately 4.5. Typically, the brightness will be greater than approximately 1.0, for example, greater than approximately 2.0. In other words, an inclusion effect of microfibrillated cellulose has the effect of reducing glare. Brightness can be determined according to the method described in the examples below.

[00118] In other embodiments, the dry paint film obtained from a paint composition has a mud crack thickness of at least approximately 1000 µm, for example, at least approximately 1050 µm or at least approximately 1100 µm or at least approximately 1150 µm. In other words, an inclusion effect of microfibrillated cellulose inclusion has the effect of reducing the slurry cracking propensity of the dry paint film. The thickness of the mud crack can be determined according to the method described in the examples below. Preparation Methods

[00119] Certain milling base and paint composition embodiments of the present invention can be prepared according to conventional methods known in the art. This comprises combining, for example, mixing and processing grinding base components and/or paint in appropriate amounts (depending on the desired paint composition) and under suitable conditions to obtain the grinding base or a paint composition . The grinding base and/or paint components can be processed by grinding or in a high speed dispersion tank where the pre-mixed components are subjected to high speed agitation by a circular blade, teeth attached to a swivel shaft. The processed composition is then typically diluted by stirring with a suitable amount of solvent for the type of paint desired to produce the final paint product. applications

[00120] The paint composition of the present invention can be applied to a substrate, for example, to an article of manufacture that constitute many and several (for example, an article of craft, a piece of furniture, a vehicle or an oceanic vessel , piping and the like) or a surface, eg the surface of a building element (eg interior/exterior walls, roofs and floors of a residence, exterior fences and adornments and the like).

[00121] Also provided is a canned paint comprising the paint composition of the second aspect of the invention. The term 'in a can' is used here to refer to any suitable container for the paint, for example a can, a barrel, a jar or a bag. The container can be formed from any material suitable for containing ink such as, for example, metal, plastic and glass.

[00122] For the avoidance of doubt, this patent application is directed to the subject matter defined in the following numbered paragraphs:

[00123] The ink milling base, which comprises microfibrillated cellulose, wherein the microfibrillated cellulose is present in an amount ranging from approximately 0.1% to approximately 10% by weight based on the total weight of a formulated ink composition starting from said base for grinding.

[00124] The milling base according to paragraph 1, which also comprises the inorganic particulate material co-processed as the main pigment and/or as the extender pigment, wherein said particulate organic material is co-processed with a fibrous substrate comprising cellulose during the preparing said microfibrillated cellulose.

[00125] The grinding base according to paragraph 1 or 2, which comprises main pigment and/or extender pigment, other than the co-processed inorganic particulate material of claim 2.

[00126] The milling base according to paragraph 1 or 3, wherein said microfibrillated cellulose is obtainable by a method comprising microfibrillating a fibrous substrate comprising cellulose in an aqueous environment by milling in the presence of a medium milling that needs to be removed after milling is complete, where milling is carried out in the absence of particulate inorganic material that can be milled.

[00127] The milling base according to paragraph 2 or 3, wherein said microfibrillated cellulose is obtainable by a method comprising microfibrillating a fibrous substrate comprising cellulose in an aqueous environment in the presence of said particulate organic material , optionally wherein the microfibrillation step comprises milling the fibrous substrate comprising cellulose in the presence of the particulate inorganic material.

[00128] The basis for grinding according to paragraph 4 or 5, wherein the grinding is carried out in a tower mill, in a sieve mill, in a medium stirred mill or in a medium stirred debris.

[00129] The milling base according to any numbered paragraph above which comprises rheology modifier other than said microfibrillated cellulose.

[00130] The grinding base according to paragraph 7, wherein said rheology modifier is a cellulose-derived rheology modifier, for example, hydroxyethyl cellulose, hydroxymethyl cellulose, hydroxypropyl cellulose, hydroxypropylmethyl cellulose, carboxymethyl cellulose or a mixture of them.

[00131] The milling base according to paragraph 8, wherein the weight ratio of microfibrillated cellulose to said cellulose-derived rheology modifier is from approximately 1000:1 to approximately 1:4.

[00132] The milling base according to any one of paragraphs 1-7, wherein said milling base is free of cellulose-derived rheology modifier other than said microfibrillated cellulose.

[00133] The grinding base according to any one of paragraphs 1-10, which comprises titanium dioxide as a main pigment.

[00134] The grinding base according to any one of paragraphs 2-11, wherein said extender pigment is selected from one or more of an alkaline earth metal carbonate or sulfate, such as calcium carbonate, magnesium carbonate, dolomite , gypsum, a hydrated kaolin clay such as kaolin, halloysite or ball clay, an anhydrous (calcined) kaolin clay such as metakaolin or fully calcined kaolin, talc, mica, perlite, feldspar, nepheline syenite, wollastonite, diatomaceous earth, barite, glass and natural or synthetic silica or silicates.

[00135] The grinding base according to any one of paragraphs 2-11, wherein said co-processed particulate inorganic material is selected from one or more of an alkaline earth metal carbonate or sulfate, such as calcium carbonate , magnesium carbonate, dolomite, gypsum, a hydrated kandita clay such as kaolin, halloysite or ball clay, an anhydrous (calcined) kandita clay such as metakaolin or fully calcined kaolin, talc, mica, perlite, feldspar, nepheline syenite, wollastonite , diatomaceous earth, barite, glass and natural or synthetic silica or silicates.

[00136] An ink composition comprising microfibrillated cellulose, binder and solvent, wherein the microfibrillated cellulose is present in an amount ranging from approximately 0.1% to approximately 10% by weight based on the total weight of the ink composition. ink.

[00137] The paint composition according to paragraph 14, which is formulated starting from a grinding base according to any one of paragraphs 1-13.

[00138] The ink composition according to paragraph 14 or 15, wherein the binder is a latex binder.

[00139] The ink composition according to any one of paragraphs 14-16, wherein the solvent is water.

[00140] The paint composition according to any one of paragraphs 14-17, wherein said paint is formulated for use as a decorative paint, for example a matte paint.

[00141] The grinding base or ink composition according to any preceding numbered paragraph, wherein said microfibrillated cellulose and optionally the co-processed particulate inorganic material is provided in the form of an aqueous suspension or a wet pressed cake .

[00142] Use of microfibrillated cellulose as defined in paragraph 4 and/or in paragraph 5 as a rheology modifier in a paint mill base or in a paint composition.

[00143] Use of microfibrillated cellulose as defined in paragraph 4 and/or in paragraph 5 as a replacement or as a partial replacement for conventional cellulose-derived rheology modifier in a grinding base for paint or for a paint composition.

[00144] Use according to paragraph 20, wherein said conventional cellulose-derived rheology modifier is selected from hydroxyethyl cellulose, hydroxymethyl cellulose, hydroxypropyl cellulose, hydroxypropylmethyl cellulose, carboxymethyl cellulose and mixtures thereof.

[00145] Use in accordance with any one of paragraphs 20 -22 for one or more of:

[00146] increased coverage power;

[00147] increased opacity (ratio of contrast);

[00148] brightness reduction at 85° and

[00149] improved wet scraping resistance.

[00150] A substrate coated with an ink composition according to any one of paragraphs 14-19.

[00151] The coated substrate of paragraph 23, wherein the substrate is an article of manufacture or the surface of one or more construction elements.

[00152] The coated substrate of paragraph 25, wherein said building element is a wall, floor or ceiling.

[00153] The coated substrate of paragraph 25, wherein said building elements form the interior of a residence.

[00154] A paint in a can comprising the paint composition according to any one of paragraphs 14-18.

[00155] Embodiments of the present invention will now be described for illustrative purposes only, with reference to the following examples. EXAMPLES Example 1

[00156] A series of ink formulations were mixed under high shear in which the standardized cellulose component was progressively replaced by microfibrillated cellulose. Details of the formulations are given in Table 1. The microfibrillated cellulose (MFC) sample was obtained by grinding to ground calcium carbonate which has a d50 of 1.4 μm with bleached sulfate slurry from northern Botnia in a mill. with agitated medium at a specific energy of 2500 kWh/ton of pulp. The MFC used in the ink formulation was supplied in the form of an aqueous suspension comprising 2 wt% microfibrillated cellulose and 8 wt% ground calcium carbonate.

[00157] Figure 1 presents the rheology profiles (viscosity as a function of the shear rate) of the formulations used. Replacing the hydroxyethyl cellulose rheology modifier with microfibrillated cellulose prepared according to the methods described in this case maintains the ink viscosity at approximately constant high shear, but significantly increases the viscosity at a low shear rate. This will have the effect of making the paint more stable and resistant to dripping while remaining easy to paint.

Exemplo 2[00158] Table 2 presents the drag film properties of the paint formulations described in Table 1. The replacement of hydroxyethyl cellulose increases the light scattering coefficient of the film, thereby improving its opacity and hiding power . This also results in a significant reduction in gloss at 85°, which is important for a matte ink. It can also be seen that the replacement results in an improvement in the wet scratch resistance of the paint, as the loss of film thickness in the standard scratch test used is less for formulations containing microfibrillated cellulose prepared in accordance with the methods described in this case. The opacity (contrast ratio) and hiding power (which is the scatter rate required to obtain the 98% contrast ratio) were determined in accordance with ISO 6504-1. Gloss was determined in accordance with ISO 2813. Wet scratch resistance was determined in accordance with ISO 11998.

Example 2

[00159] A second series of paint formulations, this time with a part of the talc replaced by a coarse calcium carbonate (which has a d50 of 6.5 µm, was mixed under high shear, in which the standard hydroxyethyl cellulose component was replaced progressively and by microfibrillated cellulose.The details of the formulations are presented in Table 3 and the properties of the paint films in Tables 4a and 4b.

[00160] The slurry propensity of these paints to crack was evaluated by dragging films that increase in thickness across their width and recording the film thickness in microns in that crack that appears after the first drying. The greater the thickness at which cracking is observed, the less likely the paint is to give crack problems in use.

[00161] Mud crack was determined as follows: Materials and apparatus:

[00162] Substrate: plasterboard

[00163] Wedge applicator (300 to 1500 µm wet film thickness)

[00164] Bar applicator series (wet film thickness 1500, 1750, 2000, 2250 and 2500 μm)

[00165] Ruler (0 to 300 mm) Procedure:

[00166] The paint is applied onto the plasterboard substrate (before Rotothinner analysis eliminates the additional introduction of air into the paint) using the wedge applicator or the series of bars or both if the final approximate result is not known. The applicator is slowly dragged across the substrate to allow any air bubbles to disperse.

[00167] Coatings are dried at 23°C +/- 2°C and 50% +/- 5% relative humidity and left for 24 hours. Gypsum board needed to be laid flat over the bookcase or similar and left to reduce the risk of premature cracking. measurement - wedge applicator

[00168] The quoted result is the point on the paint film where cracks appear within every 1 cm until the end of the film; the line had to be dragged along the cracks. The cracks that formed as a result of the air bubbles should be excluded.

[00169] The distance between the left edge of the film (300 μm edge) and the line is measured. result calculation

[00170] When the distance between the thickness of 300 μm and 1500 μm of the wet film is 10 cm, the actual thickness of the film on which the line is dragged can be calculated by: Mud Crack (μm) = (Line distance thickness 300 μm (cm) x 120) + 300 Measuring-bar applicators

[00171] Record the thinnest wet film thickness that shows evidence of mud cracking (excluding any cracking caused as a result of air bubbles) as the final result.

[00172] The results of the cracking of the mud present below were determined according to the measurement with the wedge applicator.

[00173] The propensity that these paint films have to gloss - that is, to increase gloss when rubbed - was also determined and the results recorded as the increase in gloss at 85° after 50 scraping cycles.

[00174] Gloss formation was determined as follows. Materials and equipment:

[00175] -Substrate: glass panel, 4 mm thick, dimensions 30 cm x 10 cm

[00176] -Block applicator with a gap of 100 μm

[00177] -Erichsen Automatic Film Applicator (509 mk111)

[00178] -Gloss Meter: Sheen Tri Glossmaster 20/60/85°

[00179] -Erichsen Scrape Tester

[00180] - Support for sponge, stainless steel, weight 360 g

[00181] -Block for sponge plus abrasive block

[00182] - Cloth, similar to cloth J Procedure:

[00183] The test film is applied onto the glass substrate using Erichsen's automatic applicator.

[00184] The coated panel is dried at 23°C +/- 2°C and 50% +/- 5% relative humidity and left for 24 hours.

[00185] The brightness is measured (usually at 85°; 5 separate areas below the panel length, quoting the average value). This is the 'initial glow'.

[00186] The glass panel is placed over the abrasion tester and secured.

[00187] The cloth is wrapped around the sponge block and abrasive block and placed in the sponge holder, ensuring that the block / cloth is protruding approximately 5mm out of the bottom of the sponge holder.

[00188] The sponge holder is attached to the top of the glass panel with the cloth in contact with the paint film.

[00189] The paint film is scrubbed / washed for 50 cycles.

[00190] The gloss over the area rubbed by the cloth is measured again (in the same way as the initial gloss). The measured brightness again is the 'final brightness'.

[00191] The result of the quoted brightness is the increase in brightness (final brightness - initial brightness).

Exemplo 3[00192] A new piece of cloth needed to be used for each rub, the same side of the cloth needed to be used each time. If the cloth has a noticeable pile it would need to be placed around the sponge so the pile will be rubbed in the same direction.

Example 3

The microfibrillated cellulose sample from Example 1 was diluted to 2.5% by weight of total solids and passed once through a GEA Niro Soavi homogenizer (model: Pony NS2006L) at a pressure of 500 Kpa. The product from the homogenizer was then concentrated back to 10% solids (2% microfibrillated cellulose) by centrifuge and used progressively to replace the hydroxyethyl cellulose in the equivalent formulation as used in Example 2. Formulation details are provided in Table 5.

[00194] The optical properties of the paint films obtained from these formulations are summarized in Table 6. As can be seen, the additional treatment leads to a greater improvement in light scattering and, therefore, in the opacity of the paint. Rheology profiles are shown in Figure 2 - again microfibrillated cellulose improves formulation viscosity at low shear.

Claims (24)

1. Ink composition, characterized in that it comprises one or more rheology modifiers, a binder, a solvent, wherein the one or more rheology modifiers comprises microfibrillated cellulose, wherein the microfibrillated cellulose is present in an amount in the range from 0.1% to 10% by weight based on the total weight of an ink composition, where the microfibrillated cellulose has a d50 in the range of 5 µm to 500 µm, as measured by laser light scattering, and in that the microfibrillated cellulose has a fiber slope of 20 to 50, and that the microfibrillated cellulose improves one or more of the paint composition properties selected from the group consisting of improved wet scratch resistance of the dry film (determined per ISO 11998), significant reduction in gloss at 85° (determined per ISO 2813), reduced gloss and reduced slurry cracking propensity compared to an equivalent paint composition do not buy nding microfibrillated cellulose as a rheology modifier. 2. Paint composition according to claim 1, characterized in that the binder is a latex binder, and the solvent is water. A paint composition according to claim 1, characterized in that the paint composition is formulated for use as a decorative paint comprising a matte paint. 4. Ink composition according to claim 1, characterized in that the ink composition further comprises a cellulose-derived rheology modifier, selected from the group consisting of hydroxyethyl cellulose, hydroxymethyl cellulose, hydroxypropyl cellulose, hydroxypropylmethyl cellulose, carboxymethyl cellulose or a mixture thereof. 5. Ink composition according to claim 1, characterized in that the microfibrillated cellulose maintains the viscosity of the ink, as determined in accordance with ISO 2884-1, at high shear speed (1/s) , of at least 100, and significantly increases the ink viscosity at a low shear rate of not more than 10, thus improving the stability and drip resistance of the ink composition. 6. Ink composition according to claim 1, characterized in that the dry ink film has a gloss at 85° less than 7.0. 7. Ink composition according to claim 1, characterized in that the ink composition has a wet scratch resistance of no more than 45 µm. 8. Ink composition according to claim 1, characterized in that the reduction in brightness at 85° is less than 5.8. 9. Paint composition according to claim 1, characterized in that it has a mud crack thickness of at least 1000 µm. 10. Ink composition according to claim 1, characterized in that it additionally comprises a rheology modifier other than microfibrillated cellulose, which is a rheology modifier not derived from cellulose. 11. Paint composition according to claim 10, characterized in that the non-cellulose-derived rheology modifier is selected from the group consisting of associative acrylic thickeners, polyacrylates, emulsion copolymers, dicyanamide, triols, polyoxyethylene ether, urea, sulfated castor oil, polyvinyl pyrrolidone, sodium alginate, xanthan gum, sodium silicate, acrylic acid copolymers and mixtures thereof. 12. Ink composition according to claim 10, characterized in that the non-cellulose-derived rheology modifier may be present in an amount of up to 5% by weight. 13. Ink composition according to claim 1, characterized in that the diluent pigment is selected from the group consisting of alkaline earth metal carbonate and sulphate and mixtures thereof. 14. The paint composition according to claim 1, characterized in that the extender pigment is selected from the group consisting of calcium carbonate, magnesium carbonate, dolomite, gypsum, a hydrated kandita clay, an anhydrous kandita clay, talc , mica, perlite, feldspar, nepheline syenite, wollastonite, diatomaceous earth, barite, glass, natural silica, synthetic silica, natural silicates, and synthetic silicates. 15. Paint composition according to claim 1, characterized in that the main pigment is selected from the group consisting of insoluble, finely ground, natural or synthetic, inorganic or organic dispersed particles, which when dispersed in a liquid vehicle, provide color. 16. Ink composition according to claim 1, characterized in that the main pigment is selected from the group consisting of titanium dioxide, carbon black, calcium sulfate, iron oxide and the blue phthale copper complex. 17. Ink composition according to claim 1, characterized in that the main pigment has an average particle size (d50) of 0.1 µm to 20 µm, as determined by Sedigraph. 18. Ink composition according to claim 1, characterized in that the diluent pigment has an average particle size (d50) of 0.1 µm to 20 µm, as determined by Sedigraph. 19. Ink composition according to claim 1, characterized in that the co-processed particulate inorganic material has an average particle size (d50) of 0.1 µm to 20 µm, as determined by Sedigraph. 20. The paint composition of claim 1, characterized in that the co-processed particulate inorganic material is selected from the group consisting of alkaline earth metal carbonate or sulfate. 21. A paint composition according to claim 1, characterized in that the co-processed particulate inorganic material is selected from the group consisting of calcium carbonate, magnesium carbonate, dolomite, gypsum, a hydrated Kandiite clay, kaolin, halloysite , ball clay, an anhydrous (calcined) Kandita clay, metakaolin, fully calcined kaolin, talc, mica, perlite, feldspar, nepheline syenite, wollastonite, diatomaceous earth, barite, glass and natural or synthetic silica or silicates. 22. Ink composition according to claim 1, characterized in that the microfibrillated cellulose is additionally treated in a homogenizer under humid conditions. 23. Ink composition according to claim 1, characterized in that the ink composition is free of cellulose-derived rheology modifier without being said microfibrillated cellulose. 24. Paint in can, characterized in that it comprises a paint composition as defined in claim 1.

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