Low viscosity cm-mfc, method for producing a low viscosity cm-mfc

Description

1 / 21 Low-viscosity CM-MFC, method for producing a low-viscosity CM-MFC Field of Invention

[001] The present invention relates to a low viscosity CM-MFC comprising a degree of substitution of 0.2-0.29, preferably with a viscosity between 6700-9900 cP with an R4 spindle at 100 rpm at 6% w / w, a viscosity between 65-85 cP with an R4 spindle at 10 rpm at 0.8% w / w, a method for producing a low viscosity CM-MFC, comprising:

[002] - Defibrate CMC, with DS between 0.20 — 0.29, using a rotating disc and a stationary rotor with an aqueous dispersion of 4-10% w / w, to obtain a CM-MFC whose average fiber diameter is between 0.8 μm and 8 μm. Background

[003] Carboxymethyl microfibrillated cellulose is traditionally a homogeneous and stable suspension, characterized as useful in end-use products, including food, cosmetics, pharmaceuticals, paints and drilling muds.

[004] Carboxymethyl fibrillated cellulose (CM-MFC) can be used, for example, in cosmetic applications as a thickener, shape-holding agent, emulsion stabilizer or dispersion stabilizer in the area of ​​cosmetic products such as face powders, foundations, exfoliating facial washes, packaging, cleansing foams, cleansing creams, hair mousses, shampoos, soaps, lotions, hair dyes, hair bleaches, mascara, eyeliners, manicure products and antiperspirants, without Petition 870250085602, dated 09 / 22 / 2025, page 12 / 44 2 / 21 any limitation. Sometimes, a rolling effect may occur, in which the composition applied for skin care detaches from the skin and forms undesirable clumps.

[005] In the area of ​​household products, the rheological properties of the present carboxymethyl microfibrillated cellulose (CM-MFC) and its ability to stabilize emulsions, dispersions and foams may be useful in areas such as detergents, shampoos, cleaning products and air fresheners. Specific examples include, but are not limited to, laundry products (including detergents, stain removers and fabric treatment compositions such as fabric softeners); shampoos for carpets and upholstery; toilet cleaners (particularly those dispensed in liquid or gel form); air fresheners; and general-purpose cleaning agents, including liquids, gels, pastes and foams used for cleaning and / or disinfecting household surfaces.

[006] In the paper manufacturing and treatment area, the carboxymethyl microfibrillated cellulose (CM-MFC) of the present invention may be useful in modifying and / or stabilizing emulsions; sizing; retention; clarification; absorbance; drainage; formation (such as through the function of flocculation aids); control of deposits or incrustations (by inhibiting the formation and / or growth of inorganic deposits); water treatment; dehydration; film and membrane formation; crosslinking of polyelectrolytes; removal of harmful organic and / or inorganic materials; in paper coatings; and in improving properties such as stiffness, moisture resistance, absorption, softness, toughness, tear resistance and folding resistance. Petition 870250085602, dated 09 / 22 / 2025, page 13 / 44 3 / 21

[007] In the context of papermaking, fouling control refers to preventing the formation of calcium carbonate and calcium oxalate deposits during the pulping process. Fouling control can be achieved by dispersing salt crystals in the medium to prevent growth and deposition, inhibiting nucleation, or modifying the crystal growth mechanism to prevent the formation of crystalline forms that will lead to deposit formation. The use of carboxymethyl microfibrillated cellulose (CM-MFC), with a particle size of µm or smaller, stabilized with appropriate functional groups, can serve to control fouling formation, as such microcarriers inhibit the growth of crystals that leads to deposition. In addition, cellulosic materials would be easier to recover from the pulping process due to their organic nature.Preferred functional groups include phosphate / phosphonate groups, carboxylate groups, and sulfate / sulfonate groups. Alternative functional groups and appropriate usage levels can be easily determined by experts in the field, based on the specific usage environment.

[008] Derivatized microfibrillar cellulose can also be used in papermaking machines to increase the drainage and / or dewatering rate during papermaking; to retain dispersed organic and / or inorganic particles (such as fine cellulose particles, fillers, sizing agents, pigments and / or clays); to retain harmful organic and inorganic particulate matter; to improve the uniformity of paper sheet formation; and to improve the strength of a paper sheet. With regard to drainage, drainage aids are additives that increase the rate of Petition 870250085602, dated 09 / 22 / 2025, page 14 / 44 4 / 21 Water removal from a paper pulp in a paper machine. These additives increase machine capacity and therefore profitability by allowing faster sheet formation. Microfibrillar cellulosic derivatives with anionic charge are capable of significantly increasing drainage, either alone or in combination with other charged polymers.

[009] The derivatized microfibrillar cellulose of the present invention can also be used in coated papers, where cellulose derivatives can be used to control the rheology of the colored coating and provide water retention, thereby controlling the amount of liquid that permeates the base sheet.

[010] In coating compositions, such as paints and printing inks, derivatized microfibrillar polysaccharides can provide rheological modification, improving properties such as splash, leveling, drip resistance, flooding and flotation, and may have particular utility in gel paints. They can also improve the dispersion and / or stabilization of pigments and act as charge or flow control agents, including in paints such as inkjet inks.

[011] There is a need for a carboxymethyl microfibrillated cellulose (CM-MFC) that has a relatively low degree of substitution with low viscosities that provide, for example, good spreadability and low dripping or runoff.

[012] For example, document EP 3126570 B1 describes a method for producing carboxymethyl microfibrillated cellulose (CM-MFC), in which the cellulose-based fiber material, in which the linkages Petition 870250085602, dated 09 / 22 / 2025, page 15 / 44 5 / 21 internal cellulose fibers were weakened by preliminary cellulose modification, it is subjected to a disintegration treatment to a consistency of 10-50% by means of repeated successive impacts from opposite directions. CM-MFC has a crystallinity of 0.1-0.35 and a degree of substitution of 0.1-0.2; zero shear viscosity of 1,000-50,000 Pa-s and a yield strength of 1 to 50 Pa, when measured at a consistency of 0.5%, having an average diameter of 100-1000 micrometers, with an anionic charge of 1.00-1.55 mmol / g (0.33-0.51). This document describes a method for obtaining CMMFC with a high consistency of 10-50%, in which the fiber was subjected to carboxymethylation with a degree of substitution between 0.12-0.20 and, with a consistency of 0.8% and 10 rpm, exhibits a viscosity > 5000 cP. The current CM-MFC with a consistency of 0.8% and 10 rpm has a much lower viscosity, between 65-85 cP.

[013] US patent 9909256 BB describes a carboxymethyl microfibrillated cellulose (CM-MFC) with lengths greater than 1 µm, while the diameter typically remains less than 200 nm. The document discloses a method for fibrillating cellulose in a homogenizer with a consistency of 1.5 to 3.5% and homogenized at a pressure of 300 to 650 bar; in which it is fibrillated to a degree with a Brookfield viscosity greater than 35,000 mPa-s (2 passes with a consistency of 1%: 30,000 mPa-s, 4 passes with a consistency of 1%: 39,000 mPa-s) at a measurement consistency of 0.8% and a rotation speed of 10 rpm. Furthermore, CM-MFC exhibits a substitution of 0.6 to 1.2 mmol / g, corresponding to approximately 0.2-0.4. The CM-MFC of the present invention is not obtained by homogenization, and has a larger dimension than disclosed, where the consistency of refining Petition 870250085602, dated 09 / 22 / 2025, p. 16 / 44 6 / 21 is 6% and we use rotor / stator mechanical refining resulting in a CM-MFC with a consistency of 0.8% at 10 rpm and viscosity between 65-85 cP, in contrast to a viscosity with a consistency of 0.8% at 10 rpm of 10000 cP from document US 9909256 BB.

[014] Document EP 3951050 A1 describes a carboxymethylated microfibrillated cellulose (CM-MFC) with a degree of substitution of 0.01-0.5 and a degree of crystallization of type I cellulose of 50% or more, in a water-based medium. The patent discloses a CM-MFC with an average diameter of 10.0 to 150.0 μm and viscosity (6 rpm, 25 °C) of 1,000 to 30,000 mPa.sa 1% (w / v) and substitution of 0.01-0.5 (0.1-2.5 mmol / g). The carboxymethylation of the cellulose is carried out by monochloroacetic acid in an alcoholic solvent. The CM-MFC of the present invention has a viscosity ranging from 111.9-121.9 cP at 1% solids at 60 rpm, 25°C and a viscosity ranging from 65-85 cP at 0.8% solids at 10 rpm, 25°C, in contrast to viscosities up to 4000 cP of EP 3951050 A1.

[015] Document EP 2782937 B1 describes a method for manufacturing water-insoluble carboxymethylated microfibrillated cellulose (CM-MFC) with a degree of substitution between 0.05 and 0.35 carboxymethyl groups per anhydroglucose unit, wherein the carboxymethylation reaction is carried out, at least partially, with a consistency of 50% or more. Refining is done in discs or cones to a consistency between 1 and 30% w / v, and the CM-CMF exhibits a substitution of 0.1 to 0.25 and a loading of 0.3 to 0.77 mmol / g, with a zero shear viscosity of 5,000 to 100,000 Pa.s, measured at a concentration of 0.5% in water. The cellulose fiber is treated to form a lightly carboxymethylated cellulose with such a degree of substitution that it becomes water-insoluble, with a Petition 870250085602, dated 09 / 22 / 2025, page 17 / 44 7 / 21 an alkalizing agent (sodium hydroxide) and an anionic agent, such as sodium monochloroacetic acid (SMCA). This reveals that the wood may be from long-fiber wood trees such as spruce, pine, fir, larch, red spruce or hemlock, or from short-fiber wood trees such as birch, poplar, alder, eucalyptus or acacia, in a chemical pulp of the sulfated wood pulp type with fibers of 15 to 25 μm and length greater than 500 μm. The CM-MFC of the present invention has a viscosity ranging from 111.9-121.9 cP at 1% solids at 60 rpm, 25°C and a viscosity ranging from 65-85 cP at 0.8% solids at 10 rpm, 25°C, in contrast to viscosities up to 4000 cP of EP 3951050 A1.

[016] The present invention provides a carboxymethyl microfibrillated cellulose (CM-MFC) that has a relatively low degree of substitution with low viscosities. Summary of the Invention

[017] A first objective of the present invention is a low viscosity CM-MFC comprising a degree of substitution of 0.20,29, preferably with a viscosity between 6700-9900 cP with an R4 spindle at 100 rpm at 6% w / w and a viscosity between 65-85 cP with an R4 spindle at 10 rpm at 0.8% w / w.

[018] Another objective of the present invention is to provide a method for producing a low viscosity CM-MFC, comprising:

[019] - defibrate the resulting CMC with a rotating disc and a stationary rotor with a water dispersion of 4-10% w / w to obtain a CM-MFC to an extent where the average diameter of the CM-MFC fiber is between 0.8 μm and 8 μm. Petition 870250085602, dated 09 / 22 / 2025, p. 18 / 44 8 / 21

[020] Preferably, the CM-MFC obtained has a viscosity between 6,700 and 9,900 cP, measured with an R4 spindle at 100 rpm at 6% w / w, and a degree of crystallinity of 38-49%. Figures

[021] Fig. 1 is a SEM image of a BEKP CMC used in the present invention at a magnification of 500x.

[022] Fig. 2 is a SEM image of a BEKP CMC used in the present invention at a magnification of 1,000x.

[023] Fig. 3 is a SEM image of a BEKP CMC used in the present invention at a magnification of 5,000x.

[024] Fig. 4 is a SEM image of the CM-MFC of the present invention at a magnification of 15,000x.

[025] Fig. 5 is a SEM image of the CM-MFC of the present invention at a magnification of 15,000x.

[026] Fig. 6 is a SEM image of the CM-MFC of the present invention at a magnification of 40,000x.

[027] Fig. 7 is a SEM image of the CM-MFC of the present invention at a magnification of 40,000x.

[028] Fig. 8 is an image of the CM-MFC at 6% w / w in water of the present invention.

[029] Fig. 9 is a graphical representation of the evolution of the particularity with the input of Net Specific Energy (kWh / t) during the refining of CM-MFC of the present invention.

[030] Fig. 10 is a graphical representation of the evolution of viscosity with the input of Total Specific Energy (kWh / t) during the refining of CM-MFC of the present invention. Petition 870250085602, dated 09 / 22 / 2025, p. 19 / 44 9 / 21

[031] Fig. 11 is a graphical representation of the evolution of % Particle x Viscosity during the refining of CM-MFC of the present invention.

[032] Fig. 12 is a graphical representation of the comparative viscosity behavior of the original CMC and the CM-MFC obtained from the present invention. Detailed Description of the Invention

[033] The present invention is directed to a low viscosity CM-MFC.

[034] MFC refers to microfibrillated cellulose, which has cellulose microfibrils or bundles of microfibrils separated from the fibrous cellulose-based raw material. The term fibrillation generally refers to the mechanical disintegration of the fibrous material through work applied to the cellulose fiber, where the cellulose fibrils are detached from the fibers or fiber fragments. Often used interchangeably, the names microfibrillated cellulose (MFC) and nanofibrillated cellulose (NFC) are distinct products with distinct characteristics. Fibrillated cellulose can be classified as NFC and MFC. NFC is a nanofibrillated cellulose with fibrils typically up to 100 micrometers in length and ranging in diameter from 3 to 100 nm. MFC is microfibrillated cellulose with fibrils that are generally of indefinite length, but usually cellulose fibers measuring 1 to 4 mm, as illustrated in Figures 1, 2, and 3, with fibrillated diameters greater than 100 nanometers.The methods for measuring the diameter and length of NFC and MFC are known to experts, with the CSA 25100 standard for cellulose nanomaterials being preferred if necessary. Petition 870250085602, dated 09 / 22 / 2025, p. 20 / 44 10 / 21 on Test Methods for Characterization. The dimensions and size distribution of the fibrils depend on the refining method and efficiency. In aqueous dispersion, MFC typically presents as a gelatinous, light, or almost colorless material. Preferably, the MFC of the present invention is a derivatized MFC, more preferably a carboxymethylated MFC (CM-MFC). Figures 4 to 7 illustrate the CM-MFC of the present invention.

[035] Derivatization of MFC provides CM-MFC with groups with electrostatic functionality, and the derivatized microfibrillar cellulose CM-MFC of the present invention may exhibit a degree of substitution between 0.2 and 0.29, with an ionic charge between 119-136 meq / 100g, resulting in a viscosity between 6700-9900 cP with an R4 spindle at 100 rpm at 6% w / w; a viscosity between 110-130 cP at 60 rpm at 1% w / w; and a viscosity between 6585 cP at 10 rpm at 0.8% w / w. Figure 8 is an image of the CM-MFC of the present invention in water at 6% w / w.

[036] The modified carboxymethylated fibrous material used as feedstock may be based on any plant material containing cellulose that has been subjected to a derivatization process, forming a CMC. The source plant material may be wood. The wood may come from long-fiber timber trees such as pine, larch, fir, Douglas fir or hemlock, or from short-fiber timber trees such as birch, poplar, aspen, alder, eucalyptus or acacia, or a mixture of coniferous and hardwoods.

[037] In one aspect of the present invention, the pulp is prepared from a pulp such as a mechanical pulp, a thermomechanical pulp, a chemical-thermomechanical pulp, a pulp Petition 870250085602, dated 09 / 22 / 2025, p. 21 / 44 11 / 21 chemical (e.g., Kraft, Soda, or Sulfite), a bleached pulp, a recycled pulp (optionally combining cleaning and deinking steps), a steam-exploded fiber pulp, or a biologically treated (enzymatically) pulp. Preferably, CMC is obtained from cellulose fibers obtained by kraft pulping or pulping via the kraft process.

[038] Examples of wood pulps used to obtain CMC include mechanical pulp, thermomechanical pulp, chemothermomechanical pulp, and chemical pulp. For example, bleached eucalyptus kraft pulp (BEKP), bleached northern softwood kraft pulp (NSBK), bleached softwood kraft pulp, bleached hardwood pulp, unbleached softwood and hardwood kraft pulps, sulfite-bleached pulp, and bleached chemothermomechanical pulp (BCTMP) are used to obtain CMF. Each type of pulp provides slightly different CMFs, with distinct properties and dimensions. Preferably, the CMC, carboxymethylated modified fibrous material, is derived from hardwood pulp; preferably, the CMC pulp from bleached eucalyptus kraft pulp (BEKP) is used in the present invention.

[039] The raw material of cellulose comprises fibers in bundles of fibrils. When mechanically disintegrated, the cellulose fibrils are isolated from the cellulose bundles. In this sense, MFC (microfibrillated cellulose) refers to cellulose or lignocellulose fibers that are partially or totally fibrillated, which can be obtained by a variety of processes known in the art. As cellulose found in nature has several hierarchical levels of organization and orientation, cellulose fibers comprise a layered secondary wall structure, Petition 870250085602, dated 09 / 22 / 2025, page 22 / 44 12 / 21 within which the macrofibrils are arranged. The macrofibrils comprise multiple microfibrils, which further comprise cellulose molecules arranged in crystalline and amorphous regions. Preferably, the cellulose used in the present invention has a degree of crystallinity between 52% and 62%.

[040] Fibrillation-treated fibrous material dispersion is a mixture of fibrous material and water, preferably BEKP CMC and water, forming a CMC paste. CMC paste can generally refer to whole fibers, separate parts (fragments) of them, bundles of fibrils, or fibrils mixed with water. Typically, the fibrous material dispersion is a mixture of these elements, the proportions of which depend on the degree of processing. Preferably, the fibers are mixed with water and, more preferably, the fibers are BEKP pulp CMC, refined between 4 and 10% w / w. As can be observed, CMC allows the use of a higher solids content for refining compared to traditional MFC, which requires larger quantities of solvent, such as water.

[041] In one aspect of the present invention, cellulose fibers are first derivatized and then refined. Preferably, the cellulose is carboxymethylated to a degree of substitution between 0.2 and 0.29 to provide carboxymethylated cellulose (CMC) and then refined to a median diameter (d50) of less than 8 μm, preferably refined to a diameter ranging from about 0.8 μm to 8 μm. In one aspect of the present invention, the CMC obtained is refined to a gross specific energy between 450 and 580 kWh / t. Petition 870250085602, dated 09 / 22 / 2025, p. 23 / 44 13 / 21

[042] In terms of general properties, the CM-CMC of the present invention has specific rheological attributes that include at least a desired low viscosity with a reasonable degree of substitution. Preferably, the CM-MFC of the present invention comprises a shear of 35-44 cP at 50 rpm; 0.85% w / w, with a viscosity between 6700-9900 cP with an R4 spindle at 100 rpm at 6% w / w; a viscosity between 110-130 cP at 60 rpm at 1% w / w; a viscosity between 65-85 cP at 10 rpm at 0.8% w / w. The CM-MFC of the present invention also has a transmittance ranging from 45% to 59%, with a wavelength of 660 nm and a conductivity of 2.53-2.60 mS / cm at 1% w / w.

[043] Microfibrillation is a process in which cellulose microfibrils are released or partially released as individual species or as small aggregates, compared to pre-microfibrillated pulp fibers. Typical cellulose fibers include larger aggregates of hundreds or thousands of individual cellulose fibrils.

[044] Typically, the MFC used in the present invention is a fibrillated cellulose comprising cellulose fibrils with a diameter of less than 0.7 micrometers. As the diameter of the cellulose fibrils depends on the origin of the wood and the fibrillation method employed, MFCs from different wood origins and from previous treatment processes, such as pulping, can provide MFCs with different characteristics. Examples of fibrillation are single or multiple pass refining, with disintegration by high shear or fibril release, carried out with a refiner, grinder, homogenizer, colloid, friction grinder, ultrasonic sonicator, single or twin screw extruder, fluidizer such as microfluidizer, macrofluidizer or other Petition 870250085602, dated 09 / 22 / 2025, page 24 / 44 14 / 21 Fluidizer-type homogenizer. Depending on the method, the product may also contain fines, nanocrystalline cellulose, or, for example, other chemicals present in wood fibers or in the papermaking process. Preferably, mechanical fibrillation is used to obtain the CM-MFC used in the present invention. Preferably, a mechanical fibrillation method such as those disclosed in PCT WO21226693 A1 may be used; the preferred configuration is to subject the CMC fiber in a pulp to multiple mechanical impacts with non-cutting bars arranged in a ring formation of projections. Two concentrically arranged rings, facing each other, with several bars as high-rotation projections, transmit kinetic energy to the fibers that produce the CM-MFC, such as the Atrex equipment.Alternative refining can be employed, using any type of refiner, i.e., fibrillation with low, medium or high shear with a rotating disc and a stator, to obtain the MFC used in the present invention. Preferably, the CMC used in the present invention is obtained from refining methods that operate with net energy inputs between 300 and 450 kWh / t, to obtain a CM-MFC with a diameter between 200 and 700 nanometers.

[045] Fig. 9 is a graphical representation of the evolution of viscosity with the input of Gross Specific Energy (kWh / t) and Fig. 10 with the input of Net Specific Energy (kWh / t) during the refining of the CM-MFC of the present invention with degrees of substitution of 0.20 and 0.29, which illustrates the increase in viscosity with the input of energy.

[046] Microfibrillation can be performed by applying energy to a pulp under conditions sufficient to produce Petition 870250085602, dated 09 / 22 / 2025, p. 25 / 44 15 / 21 microfibrillar polysaccharides. The pulp can be a carboxymethyl cellulose, CMC. More specifically, the refining can be carried out in one or more stages. For example, a cellulose pulp can be refined to a predetermined diameter, after which the material comprising cellulose undergoes further refining until the desired level of microfibrillation is obtained. In one embodiment, the refining can be carried out in a single stage, obtaining the CM-MFC used in the present invention. In a preferred embodiment, the CMC is passed through a refiner under conditions sufficient to produce a CM-MFC; these conditions may include a milling energy of at least 300 kWh / t, and the passage of the CM-MFC through the refiner can be carried out one or more times, feeding back into the same refiner or using sequential refiners.

[047] Carboxymethyl cellulose pulp (CM-MFC) can be refined by wet processing in the presence of water, forming a cellulose pulp suspension. Typically, the CMMFC suspension is refined to a concentration, or solids content, between 4 and 10% by weight, resulting in a CM-MFC with a concentration, or solids content, between 4 and 10% by weight.

[048]

[048] In one aspect, the refining method is mechanical refining with a rotating disc and a stator. In a preferred embodiment, carboxymethylcellulose is suspended in water and the resulting suspension is refined to produce microfibrillated carboxymethylcellulose or CM-MFC. In one aspect, the present invention is a method for producing a low viscosity CM-MFC, comprising:

[049] - defibrate the resulting CMC with a rotating disc and a stationary rotor, using a 4-10% aqueous dispersion Petition 870250085602, dated 09 / 22 / 2025, page 26 / 44 16 / 21 p / p, in order to obtain a CM-MFC in which the average fiber diameter varies between 0.8 μm and 8 μm.

[050] The method of the present invention shall produce a CM-MFC dispersed in water. Water is the preferred liquid for the suspension formed. Enzymes may be employed before, during or after fibrillation.

[051] Preferably, the CM-MFC obtained has a viscosity between 6,700 and 9,900 cP, measured with an R4 spindle at 100 rpm at 6% w / w, and a degree of crystallinity of 38-49%. EXAMPLE

[052] CMC Refining

[053] A CMC BEKP with a degree of substitution of 0.20-0.29 is introduced with a consistency of 4-5% solids into a DD 6700 disc refiner, which has a disc with a bar width of 1.5 mm, a channel width of 2.5 mm, a bar height of 4.00 mm and an angle of 15°. Fibrillation occurs at an operating temperature of 60° C and an edge velocity of 200 m / s or 895 rpm, and the fiber is processed until there is no increase in apparent viscosity, generally in less than 15-180 minutes.

[054] Table 1 presents the carboxylic acid content of the original CMC and of CM-MFC obtained after fibrillation of the original CMC. Table 1 Sample Carboxylic acid (mEQ / 100g) CMC-1 96.72 CMC-2 92.37 Petition 870250085602, dated 09 / 22 / 2025, p. 27 / 44 17 / 21 CMC-3 96, 18 CM-MFC 1 126.90 CM-MFC 2 127.12 CM-MFC 3 119.58 CM-MFC 4 135.26

[055] The crystallinity of the samples was evaluated with samples suspended in distilled water, each containing approximately 0.2 g of the sample. The suspensions were then transferred to Petri dishes and dried at room temperature. After drying, the films were detached and X-ray diffraction analysis was performed.

[056] The diffractograms of the samples were recorded using a Panalytical Empyrean X-ray diffractometer, belonging to the Materials for Construction Products Laboratory of the Housing and Buildings area of ​​IPT. The wavelength of CuKa radiation (λ = 1.54 Â) was used, with a Bragg angle scan of 2Θ from 5° to 30° and a step of 0.01°. The voltage and current used were 45 kV and 40 mA. The crystallinity index of the samples sent was calculated according to the expression proposed by SEGAL et al. (1959, apud TSOUKO, 2015, p.14844): Cr / =(I002-Iam / / 002)-100 where Cri is the crystallinity index, 002 is the maximum intensity referring to diffraction near the angle 2θ=23° (diffraction plane 002) and is the intensity referring to the amorphous region near the angle 2θ=18° - 19°. The results are shown in Table 2. Table 2 Petition 870250085602, dated 09 / 22 / 2025, page 28 / 44 18 / 21 Sample Crystallinity Degree (%) CMC-1 53.2 CMC-2 57.4 CMC-3 61.2 CM-MFC 1 40.0 CM-MFC 2 38.0 CM-MFC 3 44.8 CM-MFC 4 49.2

[057] The batches were also measured for viscosity. The results are shown in Table 3, as shown below: Table 3 Condition 1 Viscosity (1%, 60 rpm, 25 °C) Condition 2 Viscosity (0.8%, 10 rpm, 25 °C) Batch 1 127.4 cP 76.9 cP Batch 4 111.9 cP 69.0 cP Batch 2 120.8 cP 71.6 cP Petition 870250085602, dated 09 / 22 / 2025, page 29 / 44 19 / 21 Lot 3 121.9 cP 82.5 cP

[058] Other parameters were also measured as per Tables 5 and 5: Table 4 DS Batches Net specific energy (kWh / t) Gross specific energy (kWh / t) Fine particles (%) Viscosity cP (R4 spindle + 100RPM) with 6% consistency 1 0.28-0.29 335 457 86.9 6731 4 323 499 78.9 7091 2 0.20-0.22 377 580 82.4 9866 3 357 579 80 9393 Table 5 DS Batches Carboxylic acids (meq / 100g) Degree of crystallinity Transmittance with 0.1% consistency and wavelength of 60 nm Conductivity with 1% consistency 1 0.28-0.29 126.90 40.0% 45.64% 2.60 mS / cm 4 127.12 38.0% 45.54% 2.58 mS / cm Petition 870250085602, dated 09 / 22 / 2025, pp. 30 / 44 20 / 21 2 0.20 119.58 44.8% 58.58% 2.53 mS / cm 3 - 0.22 135.26 49.2% 56.82% 2.56 mS / cm

[059] Fig. 11 is a graphical representation of the evolution of % Fine Particles x Viscosity during the refining of CM-MFC of the present invention.

[060] Table 6 shows the viscosity results comparing the CMC initially used and the CM-MFC obtained. Table 6 Sample Viscosity (cP) 12.5 rpm 25 rpm 50 rpm 75 rpm CMC-1 (2.0%) 14.88 44.10 35.70 28.50 CMC-2 (2.0%) 13.83 26.59 20.82 17.69 CMC-3 (2.0%) 10.35 63.81 51.15 40.41 CM-MFC 1 (0.85%) 76.31 53.53 38.21 31.72 CM-MFC 2 (0.85%) 67.01 48.18 35.16 29.55 CM-MFC 3 (0.85%) 91.94 59.72 39.93 31. 95 CM-MFC 4 (0.85%) 102.75 66, 63 44.56 35, 64

[061] Figure 12 illustrates these results. As can be observed, CM-MFC exhibits pseudoplastic behavior, which is interesting in applications that require good mixing and spreadability, such as at low viscosities under stress, like in mural paintings, while at the same time remaining in place. Petition 870250085602, dated 09 / 22 / 2025, pp. 31 / 44 21 / 21 after application, which is evidenced by the high viscosity when not subjected to stress. Furthermore, when used in cosmetic applications, roll formation generally decreases due to good spreadability. Petition 870250085602, dated 09 / 22 / 2025, pp. 32-44

Claims

1 / 3 CLAIMS 1. Low viscosity CM-MFC characterized in that it comprises a degree of substitution of 0.2-0.

29.

2. CM-MFC according to claim 1, characterized in that the CM-MFC comprises a viscosity between 67009900 cP with an R4 spindle at 100 rpm at 6% w / w.

3. CM-MFC according to claim 1, characterized in that the CM-MFC comprises a viscosity between 110-130 cP at 60 rpm at 1% w / w.

4. CM-MFC according to claim 1, characterized in that the CM-MFC comprises a viscosity between 6585 cP at 10 rpm and 0.8% w / w.

5. CM-MFC according to claim 1, characterized in that the CM-MFC comprises an ionic charge between 119136 meq / 100g.

6. CM-MFC according to claim 1, characterized in that the CM-MFC is made of BEKP CMC.

7. CM-MFC according to claim 1, characterized in that CM-MFC is a BEKP CMC refined between 4-10%.

8. CM-MFC according to claim 1, characterized in that CM-MFC comprises refining a CMC to a gross specific energy between 450-580 kWh / t.

9. CM-MFC according to claim 1, characterized in that the viscosity is 35-44 cP at 50 rpm; 0.85% w / w. Petition 870250085602, dated 09 / 22 / 2025, p. 33 / 44 2 / 3 10. CM-MFC according to claim 1, characterized in that the transmittance is 45%-59% with a wavelength of 660 nm at 0.1% p / p.

11. CM-MFC according to claim 1, characterized in that the conductivity is 2.53-2.60 mS / cm at 1% w / w.

12. CM-MFC according to claim 12, characterized in that the source cellulose has a degree of crystallinity of 52%-62%.

13. CM-MFC according to claim 1, characterized in that the microfibrillated cellulose is obtained by a disc refining process.

14. CM-MFC according to claim 1, characterized in that the microfibrillated cellulose has an average diameter (d50) of less than 8 μm.

15. CM-MFC according to claim 1, characterized in that it has a diameter ranging from about 0.8 μm to 8 μm.

16. Method for producing a low viscosity CM-MFC, characterized in that it comprises the steps of: - defibrating the resulting CMC with a rotating disc and a stationary rotor, with an aqueous dispersion of 4-10% w / w, to obtain a CM-MFC such that the average diameter of the CM-MFC fibers is between 0.8 μm and 8 μm.

17. Method according to claim 16, characterized in that CM-MFC of claim 19, wherein CM-MFC comprises a viscosity between 6700-9900 cP with an R4 spindle at 100 rpm at 6% w / w. Application 870250085602, dated 22 / 09 / 2025, p. 34 / 44 3 / 3 18. Method according to claim 19, characterized in that CM-MFC has a degree of crystallinity of 3849%. Petition 870250085602, dated 22 / 09 / 2025, p. 35 / 44

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