Low viscosity CM-MFC

Abstract

The present invention relates to a low-viscosity CM-MFC comprising a degree of substitution of 0.2 to 0.29, and preferably having a viscosity of between 6700 and 9900 cP at 1% w / w using a spindle R4 at 100 rpm, and a viscosity of between 65 and 85 cP at 0.8% w / w using a spindle R4 at 10 rpm, and a method for producing a low-viscosity CM-MFC, comprising: - defibrating the obtained CMC with a 4 to 10% w / w aqueous dispersion using a rotating disc and a fixed rotor to obtain a CM-MFC with an average CM-MFC fiber diameter of between 0.8 μm and 8 μm.

Description

[Technical Field]

[0001] The present invention relates to a low viscosity CM-MFC comprising a degree of substitution of 0.2 to 0.29, preferably having a viscosity of between 6700 and 9900 cP at 6% w / w using spindle R4 at 100 rpm, and between 65 and 85 cP at 0.8% w / w using spindle R4 at 10 rpm, and to a method for producing a low viscosity CM-MFC comprising:

[0002]

[0002] - The fiberization of CMC with a DS between 0.20 and 0.29 in a 4-10% w / w aqueous dispersion using a rotating disc and a fixed rotor to obtain CM-MFC with an average fiber diameter between 0.8 μm and 8 μm. [Background technology]

[0003] Carboxymethylated microfibrillated cellulose has traditionally been characterized as a stable, homogeneous suspension, useful in end-use products including foods, cosmetics, pharmaceuticals, paints, and drilling muds.

[0004] Carboxymethylated microfibrillated cellulose (CM-MFC) can be used, for example, as a thickener, shape-retaining agent, emulsion stabilizer, or dispersion stabilizer in cosmetic applications, including, but not limited to, powder, foundation, facial scrub, pack, cleansing foam, cleansing cream, hair mousse, shampoo, soap, lotion, hair color, hair bleach, mascara, eyeliner, nail polish, and antiperspirant. Sometimes, a rolling phenomenon occurs in which the applied skin care composition separates from the skin and forms undesirable lumps.

[0005] In the area of ​​household products, the rheological properties of the present carboxymethylated microfibrillated cellulose (CM-MFC) and their ability to stabilize emulsions, dispersions, and foams may provide utility in areas such as detergents, shampoos, cleaners, and deodorizing sprays. Specific examples include, but are not limited to, laundry products (including fabric treatment compositions such as detergents, stain pre-cleaners, and fabric softeners); rug and fabric upholstery shampoos; toilet bowl cleaners (especially those provided in liquid or gel form); deodorizing sprays; and general-purpose cleaners, including liquids, gels, pastes, and foams, used to clean and / or disinfect household surfaces.

[0006]

[0006] In the field of paper making and processing, the carboxymethylated microfibrillated cellulose (CM-MFC) of the present invention may have utility in emulsion modification and / or stabilization; sizing; retention; clarification; absorption; drainage; formation (such as by acting as a flocculation aid); precipitation or scale control (such as by inhibiting the formation and / or growth of inorganic precipitates); water treatment; dewatering; film and membrane formation; polyelectrolyte cross-linking; removal of harmful organic and / or inorganic substances; in paper coating; and in improving properties such as stiffness, wet strength, absorbency, flexibility, toughness, tear resistance, and fold resistance.

[0007] In the context of papermaking, scale control refers to preventing the formation of calcium carbonate and calcium oxalate precipitates during the pulping process. Scale control can be achieved by dispersing salt crystals in the medium to prevent growth and precipitation, inhibiting nucleation, or modifying crystal growth mechanisms to prevent the formation of crystalline forms that lead to precipitation. The use of carboxymethylated microfibrillated cellulose (CM-MFC) with submicron particle size and stabilized with appropriate functional groups can help control scale precipitation, as such microcarriers inhibit crystal growth that leads to precipitation. Furthermore, cellulosic materials are easier to recover from the pulping process due to their organic nature. Preferred functional groups would include phosphate / phosphonate, carboxylate, and sulfate / sulfonate groups. Alternative functional groups and appropriate usage levels can be readily determined by those skilled in the art based on the specific use environment.

[0008] Derivatized microfibrillar cellulose can also be used in papermaking machines to increase the rate of drainage and / or dewatering during paper production; to retain dispersed organic and / or inorganic particles (such as pulp fines, 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 paper sheet strength. With regard to drainage in particular, drainage aids are additives that increase the rate at which water is removed from the paper slurry on the paper machine. These additives increase machine capacity and therefore profitability by enabling faster sheet formation. Anionically charged microfibrillar cellulose derivatives, either alone or in combination with other charged polymers, are capable of significantly increasing drainage.

[0009]

[0009] The derivatized microfibrillar cellulose of the present invention may also be used in coated papers, in which case the cellulose derivative may be used to control the rheology of the color coating and to provide water retention, thereby controlling the amount of liquid that penetrates the base sheet.

[0010] In coating compositions such as paints and inks, derivatized microfibrillar polysaccharides can provide rheology modification and improve properties such as spatter, leveling, sag resistance, float color, and float mottle, and can have particular utility in gel paints. They can also improve pigment dispersion and / or stabilization and function as charge control or flow control agents in inks such as inkjet inks.

[0011] For example, there is a need for carboxymethylated microfibrillated cellulose (CM-MFC) having a relatively low degree of substitution with low viscosity that provides good spreadability and low dripping or running.

[0012] For example, EP 3126570B1 discloses a method for producing carboxymethylated microfibrillated cellulose (CM-MFC), in which a cellulosic fibrous material in which the internal bonds of the cellulose fibers have been weakened by pre-modification of the cellulose are subjected to a disintegration treatment at a consistency of 10 to 50% through repeated successive impacts from opposite directions. The CM-MFC has a crystallinity of 0.1 to 0.35 and a degree of substitution of 0.1 to 0.2; a zero-shear viscosity of 1,000 to 50,000 Pa·s and a yield stress of 1 to 50 Pa when measured at a consistency of 0.5 percent; an average diameter of 100 to 1,000 micrometers; and an anionic charge of 1.00 to 1.55 mmol / g (0.33 to 0.51). This paper describes a method to obtain CM-MFC at high consistency of 10-50%, which is subjected to carboxymethylation with a degree of substitution between 0.12 and 0.20, and has a viscosity >5000 cP at 0.8% consistency and 10 rpm. The present CM-MFC has a much lower viscosity of between 65-85 cP at 0.8% consistency and 10 rpm.

[0013]

[0013] US9909256BB discloses carboxymethylated microfibrillated cellulose (CM-MFC) having a length exceeding 1 μm but a diameter typically remaining less than 200 nm. It discloses a method for fibrillating cellulose in a homogenizer at a consistency of 1.5 to 3.5% and a pressure of 300 to 650 bar, where it is fibrillated to a degree that it has a Brookfield viscosity of more than 35,000 mPa·s (30,000 mPa·s at 1% consistency after two passes, and 39,000 mPa·s at 1% consistency after four passes) at a measured consistency of 0.8 percent and a rotation speed of 10 rpm. Furthermore, the CM-MFC has a degree of substitution of 0.6 to 1.2 mmol / g, corresponding to approximately 0.2 to 0.4. The CM-MFC of the present invention is not obtained by homogenization and has larger dimensions than those disclosed, where the refined consistency is 6%; we use rotor / stator mechanical refinement, resulting in a CM-MFC with a viscosity between 65-85 cP at a 0.8% consistency at 10 rpm, as opposed to the viscosity of 10,000 cP at a 0.8% consistency at 10 rpm of US9909256BB.

[0014] EP 3951050 A1 discloses carboxymethylated microfibrillated cellulose (CM-MFC) having a degree of substitution of 0.01 to 0.5, a crystallinity of cellulose type I of 50% or more, and an aqueous medium. It reveals CM-MFC with an average diameter of 10.0 to 150.0 μm, a viscosity at 1 percent (w / v) of 1,000 to 30,000 mPa·s (6 rpm, 25°C), and a degree of substitution of 0.01 to 0.5 (0.1 to 2.5 mmol / g). Carboxymethylation of cellulose is carried out with monochloroacetic acid in an alcohol solvent. The CM-MFC of the present invention has a viscosity in the range of 111.9-121.9 cP at 1% solids at 60 rpm and 25°C, and a viscosity in the range of 65-85 cP at 0.8% solids at 10 rpm and 25°C, in contrast to the viscosity of up to 4000 cPs in EP3951050A1.

[0015] EP 2782937 B1 discloses a method for producing water-insoluble carboxymethylated microfibrillated cellulose (CM-MFC) having a degree of substitution of 0.05 to 0.35 carboxymethyl groups per anhydroglucose unit, where the carboxymethylation reaction is at least partially carried out at a consistency of 50% or greater. Purification is performed by disk or conical filtration to a consistency of 1 to 30% w / v. The CM-CMF has a degree of substitution of 0.1 to 0.25, a loading of 0.3 to 0.77 mmol / g, and a zero-shear viscosity of 5,000 to 100,000 Pa.s measured at a 0.5% concentration in water. Cellulose fibers are treated with an alkalizing agent (sodium hydroxide) and an anionic agent such as monochloroacetic acid, preferably sodium monochloroacetate (SMCA), to form slightly carboxymethylated cellulose with a degree of substitution that is insoluble in water. It reveals that in chemical pulps of the sulfate wood pulp type, in which the fibers are 15 to 25 μm in size and greater than 500 μm in length, the wood can be from softwoods such as spruce, pine, larch, spruce, or hemlock, or from hardwoods such as birch, poplar, aspen, alder, eucalyptus, or acacia. The CM-MFC of the present invention has a viscosity in the range of 111.9 to 121.9 cP at 60 rpm and 25°C at 1% solids, and a viscosity in the range of 65 to 85 cP at 10 rpm and 25°C at 0.8% solids, in contrast to the viscosity of up to 4000 cPs in EP 3951050 A1.

[0016]

[0016] Thus, the present invention provides a carboxymethylated microfibrillated cellulose (CM-MFC) having a relatively low degree of substitution along with a low viscosity. Summary of the Invention

[0017] A first object of the present invention is a low viscosity CM-MFC containing a degree of substitution between 0.2 and 0.29, preferably having a viscosity between 6700 and 9900 cP at 6% w / w using spindle R4 at 100 rpm, and a viscosity between 65 and 85 cP at 0.8% w / w using spindle R4 at 10 rpm.

[0018] Another object of the present invention is to provide a method for producing a low viscosity CM-MFC comprising:

[0019]

[0019] - The obtained CMC is defibrated using a rotating disc and a fixed rotor in a 4-10% w / w aqueous dispersion to obtain CM-MFC having an average fiber diameter of between 0.8 μm and 8 μm.

[0020]

[0020] Preferably, the resulting CM-MFC has a viscosity of between 6700 and 9900 cP at 6% w / w using spindle R4 at 100 rpm, and a crystallinity of 38-49%. [Brief explanation of the drawings]

[0021] [Figure 1] FIG. 1 is a MEV image at 500x magnification of the BEKP CMC used in the present invention. [Figure 2]

[0022] FIG. 2 is a MEV image at 1,000x magnification of the BEKP CMC used in the present invention. [Figure 3]

[0023] FIG. 3 is a MEV image at 5,000x magnification of the BEKP CMC used in the present invention. [Figure 4]

[0024] FIG. 4 is a MEV image of a CM-MFC of the present invention at 15,000x magnification. [Figure 5]

[0025] FIG. 5 is a MEV image of a CM-MFC of the present invention at 15,000x magnification. [Figure 6]

[0026] FIG. 6 is a MEV image of a CM-MFC of the present invention at 40,000x magnification. [Figure 7]

[0027] FIG. 7 is a MEV image of a CM-MFC of the present invention at 40,000x magnification. [Figure 8]

[0028] FIG. 8 is an image of a CM-MFC of the present invention at 6% w / w in water. [Figure 9]

[0029] FIG. 9 is a graphical representation of the change in viscosity with total specific energy (kWh / t) input during purification for a CM-MFC of the present invention. [Figure 10]

[0030] FIG. 10 is a graphical representation of the change in viscosity with net specific energy (kWh / t) input during purification for a CM-MFC of the present invention. [Figure 11]

[0031] FIG. 11 is a graphical representation of the change in % fines x viscosity during purification of a CM-MFC of the present invention. [Figure 12]

[0032] FIG. 12 is a graphical representation of the comparative viscosity behavior of the original CMC and the resulting CM-MFC of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0022]

[0033] The present invention is directed to a low viscosity CM-MFC.

[0023]

[0034] MFC refers to microfibrillated cellulose, which has cellulose microfibrils or microfibril bundles separated from cellulosic fiber raw materials. The term "fibrillation" generally refers to the mechanical disruption of fibrous material by action on cellulose fibers, where cellulose fibrils are detached from the fibers or fiber fragments. The terms microfibrillated cellulose (MFC) and nanofibrillar cellulose (NFC) are different products with different properties and are often used interchangeably. Fibrillated cellulose can be classified as NFC and MFC. NFC is nanofibrillated cellulose, typically referred to as fibrils, with lengths up to 100 micrometers and diameters ranging from 3 to 100 nm. MFC is microfibrillated cellulose, where fibrils are usually of undefined length but typically 1 to 4 mm, as shown in Figures 1, 2, and 3, and fibrillated diameters are greater than 100 nanometers. Methods for measuring the diameter and length of NFC and MFC are known to experts, and where necessary, the standard CSA 25100 for cellulose nanomaterials regarding test methods for characterization is preferred. The fibril dimensions and size distribution depend on the purification method and efficiency. In aqueous dispersion, MFC typically appears as a light or almost colorless gel-like substance. Preferably, the MFC of the present invention is a derivatized MFC, more preferably a carboxymethylated MFC (CM-MFC). Figures 4-7 show CM-MFC of the present invention.

[0024]

[0035] Derivatization of MFC provides electrostatically functionalized groups to CM-MFC, and the derivatized microfibrillar cellulose of the present invention, CM-MFC, may have a degree of substitution between 0.2 and 0.29 and an ionic charge between 119 and 136 meq / 100 g, resulting in a viscosity of between 6700 and 9900 cP at 6% w / w using spindle R4 at 100 rpm; between 110 and 130 cP at 60 rpm at 1% w / w; and between 65 and 85 cP at 10 rpm at 0.8% w / w. Figure 8 is an image of a CM-MFC of the present invention in water at 6% w / w.

[0025]

[0036] The carboxymethylated fiber material used as the starting material can be based on any plant material that contains cellulose and has been subjected to a derivatization process to form CMC. The starting plant material can be wood. The wood can be from conifers such as spruce, pine, fir, larch, Douglas fir, or hemlock, or from hardwoods such as birch, aspen, poplar, alder, eucalyptus, or acacia, or can be from a mixture of conifers and hardwoods.

[0026]

[0037] In one embodiment of the present invention, the pulp is prepared from a pulp such as a mechanical pulp, a thermomechanical pulp, a chemi-thermomechanical pulp, a chemical pulp (e.g., kraft, soda, or sulfite), a bleached pulp, a recycled pulp (optionally combined with a washing and deinking step), a steam-exploded fiber pulp, or a biologically (enzymatically) treated pulp. Preferably, the CMC is obtained from cellulose fibers obtained by kraft pulping or pulping by the kraft process.

[0027]

[0038] Examples of wood pulp used to obtain CMC include mechanical pulp, thermomechanical pulp, chemithermomechanical pulp, and chemical pulp. For example, MFCs have been obtained using bleached eucalyptus kraft pulp (BEKP), North American bleached softwood kraft pulp (NSBK), bleached softwood kraft pulp, bleached hardwood pulp, unbleached softwood and hardwood pulp, bleached sulfite pulp, and bleached chemithermomechanical pulp (BCTMP). Each type of pulp provides slightly different MFCs with different properties and dimensions. Preferably, the carboxymethylated modified fiber material CMC is derived from hardwood pulp, and CMC pulp from bleached eucalyptus kraft pulp (BEKP) is preferably used in the present invention.

[0028]

[0039] Cellulose raw materials contain fibers in the form of fibril bundles. When mechanically disintegrated, cellulose fibrils are separated from the cellulose bundles. In this sense, MFC (microfibrillated cellulose) should be understood to include partially or completely fibrillated cellulose or lignocellulose fibers, which can be achieved by various processes known in the art. Because cellulose found in nature has several hierarchical levels of organization and orientation, cellulose fibers contain layered secondary wall structures in which macrofibrils are arranged. Macrofibrils contain numerous microfibrils, which further contain cellulose molecules arranged in crystalline and amorphous regions. Preferably, the cellulose used in the present invention has a crystallinity of between 52% and 62%.

[0029]

[0040] The fibrous material dispersion subjected to fibrillation is a mixture of fibrous material and water, preferably a mixture of BEKP CMC and water, to form a CMC slurry. The CMC slurry can generally refer to whole fibers, separated portions (fragments) of those fibers, fibril bundles, or fibrils mixed with water; typically, the fibrous material dispersion is a mixture of such elements, with the ratio between components depending on the degree of processing. Preferably, the fibers are mixed with water, and more preferably, the fibers are CMC from BEKP pulp, refined to between 4 and 10% w / w. As can be noted, CMC allows for the use of a higher solids content for purification compared to conventional MFC, which requires a larger amount of solvent, such as water.

[0030]

[0041] In one embodiment of the invention, cellulose fibers are first derivatized and then purified. Preferably, the cellulose is carboxymethylated to a degree of substitution between 0.2 and 0.29 to provide carboxymethylated cellulose (CMC), which is then purified to a median diameter (d50) of less than 8 μm, preferably in the range of about 0.8 μm to 8 μm. In one embodiment of the invention, the resulting CMC is purified at a total specific energy of between 450 and 580 kWh / t.

[0031]

[0042] In terms of general properties, the CM-CMC of the present invention possesses specific rheological attributes, including at least the desired low viscosity with a reasonable degree of substitution. Preferably, the CM-MFC of the present invention has a shear of 35-44 cP at 50 rpm; a viscosity of 6700-9900 cP at 6% w / w using a spindle R4 at 100 rpm at 0.85% w / w; a viscosity of 110-130 cP at 60 rpm at 1% w / w; and a viscosity of 65-85 cP at 10 rpm at 0.8% w / w. The CM-MFC of the present invention also has a transmittance of 45%-59% at 660 nm and a conductivity of 2.53-2.60 mS / cm at 1% w / w.

[0032]

[0043] Microfibrillation is a process in which cellulose microfibrils are liberated or partially liberated as small aggregates or as individual seeds compared to the fibers of the pulp before microfibrillation. A typical cellulose fiber contains larger aggregates of hundreds or even thousands of individual cellulose fibrils.

[0033]

[0044] Typically, the MFC used in the present invention is fibrillated cellulose containing cellulose fibrils with a diameter of less than 0.7 micrometers. Because the diameter of cellulose fibrils depends on the wood source and the fibrillation method used, MFC from different wood sources and pretreatment processes such as pulping may provide MFC with different properties. Examples of fibrillation include single- or multiple-pass refining with high shear disintegration or liberation of fibrils using a refiner, grinder, homogenizer, colloidal grinder, friction grinder, ultrasonic crusher, single- or twin-screw extruder, fluidizer such as microfluidizer, macrofluidizer, or other fluidizer-type homogenizer. Depending on the method, the product may also contain fine powder, nanocrystalline cellulose, or other chemicals present, for example, in wood fibers or during the papermaking process. Preferably, mechanical fibrillation is used to obtain CM-MFC used in the present invention. Preferably, a mechanical fibrillation method such as that disclosed in PCT WO21226693A1 can be used, in which the CMC fibers in the slurry are subjected to multiple mechanical impacts with non-cutting bars arranged on a ring-shaped protrusion. Two concentric rings facing each other, such as the Atrex machine, with several bars as protrusions, transfer kinetic energy to the fibers when rotated at high speed to produce CM-MFC. Alternative refining methods using any type of refiner may also be used, namely, low-, medium-, or high-shear fibrillation using a rotating disk and stator to obtain the MFC used in the present invention. Preferably, the CMC used in the present invention is obtained from a refining method operating at a net energy input of between 300 and 450 kWh / t to obtain CM-MFC with a diameter between 200 and 700 nanometers.

[0034]

[0045] FIG. 9 is a graph showing the change in viscosity with gross specific energy (kWh / t) input and FIG. 10 is a graph showing the change in viscosity with net specific energy (kWh / t) input during the purification of CM-MFC of the present invention with degrees of substitution of 0.20 and 0.29, which shows the increase in viscosity with energy input.

[0035]

[0046] Microfibrillation can be achieved by adding energy to pulp under conditions sufficient to produce microfibrillar polysaccharides. The pulp may be carboxymethyl cellulose (CMC). More specifically, refining can be carried out in one or more stages. For example, cellulose pulp may be refined to a predetermined diameter, after which the cellulose-containing material undergoes another refinement until the desired level of microfibrillation is achieved. In one embodiment, refining can be achieved in one step to obtain the CM-MFC used in the present invention. In a preferred embodiment, the CMC is passed through a refiner under conditions sufficient to produce CM-MFC, which conditions may include at least 300 kWh / t of grinding energy, and the CM-MFC may be passed through the refiner one or more times, either by re-feeding to the same refiner or using successive refiners.

[0036]

[0047] Carboxymethylated cellulose pulp (CM-MFC) may be wet refined in the presence of water to form a cellulose pulp suspension. Typically, the CM-MFC suspension is refined at a consistency or solids content of between 4 and 10% by weight, thus providing CM-MFC at a consistency or solids content of between 4 and 10% by weight.

[0037]

[0048] In one aspect, the purification method is mechanical purification with a rotating disc and a stator. In a preferred embodiment, carboxymethyl cellulose is suspended in water and the resulting suspension is purified to produce microfibrillated carboxymethyl cellulose or CM-MFC. In one aspect, the present invention provides a method for producing low viscosity CM-MFC, the method comprising:

[0038]

[0049] - defibrating the obtained CMC in a 4-10% w / w aqueous dispersion using a rotating disc and a stationary rotor to obtain CM-MFC with an average fiber diameter of between 0.8 μm and 8 μm.

[0039]

[0050] The method of the present invention should result in CM-MFC dispersed in water. Water is the preferred liquid for the suspension to form. Enzymes can be used before, during, or after fibrillation.

[0040]

[0051] Preferably, the resulting CM-MFC has a viscosity of between 6700-9900 cP at 6% w / w using spindle R4 at 100 rpm, and a crystallinity of 38-49%.

[0041]

[0052] example

[0042]

[0053] Purification of CMC

[0043]

[0054] CMC BEKP with a degree of substitution of 0.20-0.29 was introduced at a consistency of 4-5% solids into a disc refiner DD6700 with a bar width of 1.5 mm, a channel width of 2.5 mm, a bar height of 4.00 mm, and a disc angle of 15°. Fibrillation was performed at an operating temperature of 60°C and an edge speed of 200 m / s or 895 rpm, and the fibers were processed until there was no increase in apparent viscosity, typically less than 15-180 min.

[0044]

[0055] Table 1 has the carboxylic acid content of the original CMC and the CM-MFC obtained after fibrillation of the original CMC.

[0045]

[0056] [Table 1]

[0046]

[0057] Crystallization of the samples was performed by suspending them in distilled water, each containing approximately 0.2 g of sample. The suspension was then transferred to a Petri dish and allowed to dry at room temperature. After drying, the film was peeled off and subjected to X-ray diffraction analysis.

[0047]

[0058] Diffractograms of the samples were recorded using an X-ray diffractometer, Panalytical brand, Empyrean model, belonging to the Laboratory of Materials for Building Products in the Housing and Buildings Division of IPT. A Cu Kα radiation wavelength (λ = 1.54 Å) was used, with a 2θ Bragg angle sweep from 5° to 30° with a step of 0.01°. The voltage and current used were 45 kV and 40 mA. The crystallinity of the samples was calculated according to the formula proposed by Segal et al. (1959, in TSOUKO, 2015, p. 14844): CrI = (I002 - Iam / I002) 100, where CrI is the crystallinity index, I002 is the maximum intensity pointing to the diffraction near the angle 2θ = 23° (diffraction plane 002), and Iam is the intensity pointing to the amorphous region near the angle 2θ = 18°–19°. The results are shown in Table 2.

[0048]

[0059] [Table 2]

[0049]

[0060] The batches were also measured for viscosity, and the results are shown in Table 3:

[0050] [Table 3]

[0051]

[0061] Other parameters were also measured as shown in Tables 4 and 5:

[0052]

[0062] [Table 4]

[0053]

[0063] [Table 5]

[0054]

[0064] FIG. 11 is a graphical representation of the change in % fines x viscosity during purification of a CM-MFC of the present invention.

[0055]

[0065] Table 6 shows the viscosity results comparing the initial CMC and the resulting CM-MFC.

[0056]

[0066] [Table 6]

[0057]

[0067] Figure 12 is a graphical representation of such results. As can be noted, CM-MFC is endowed with pseudoplastic behavior, which is interesting in applications such as wall coatings that require good mixing and spreadability, such as low viscosity under stress, while staying in place after application, as indicated by high viscosity when not under stress. Also, when used in cosmetic applications, the formation of rolling is usually reduced due to good spreadability.

Claims

1. Low viscosity CM-MFC containing degrees of substitution from 0.2 to 0.

29.

2. 2. The CM-MFC of claim 1, wherein the CM-MFC comprises a viscosity of between 6700 and 9900 cP at 6% w / w using spindle R4 at 100 rpm.

3. 2. The CM-MFC of claim 1, wherein the CM-MFC comprises a viscosity of between 110-130 cP at 60 rpm at 1% w / w.

4. 2. The CM-MFC of claim 1, wherein the CM-MFC comprises a viscosity of between 65-85 cP at 10 rpm at 0.8% w / w.

5. 10. The CM-MFC of claim 1, wherein the CM-MFC comprises an ionic charge between 119 and 136 meq / 100 g.

6. 2. The CM-MFC of claim 1, wherein the CM-MFC is from BEKP CMC.

7. 2. The CM-MFC of claim 1, wherein the CM-MFC is BEKP CMC refined to between 4 and 10%.

8. 10. The CM-MFC of claim 1, wherein the CM-MFC comprises purifying CMC at a total specific energy between 450 and 580 kWh / t.

9. 2. The CM-MFC of claim 1, having a viscosity of 35-44 cP @ 50 rpm; 0.85% w / w.

10. 2. The CM-MFC of claim 1, having a transmittance of 45% to 59% at a wavelength of 660 nm at 0.1% w / w.

11. 2. The CM-MFC of claim 1, having a conductivity of 2.53-2.60 mS / cm at 1% w / w.

12. 13. The CM-MFC of claim 12, wherein the original cellulose has a crystallinity of 52% to 62%.

13. 2. The CM-MFC of claim 1, wherein the microfibrillated cellulose is obtained by a disk refining process.

14. 2. The CM-MFC of claim 1, wherein the microfibrillated cellulose has a median diameter (d50) of less than 8 μm.

15. 10. The CM-MFC of claim 1 having a diameter ranging from about 0.8 μm to 8 μm.

16. A method for producing a low viscosity CM-MFC, comprising the steps of: - defibrating the obtained CMC in a 4-10% w / w aqueous dispersion using a rotating disc and a stationary rotor to obtain CM-MFC with an average CM-MFC fiber diameter of between 0.8 μm and 8 μm. A method for providing the above.

17. 19. The method of claim 16, wherein the CM-MFC is as claimed in claim 19, and the CM-MFC comprises a viscosity of between 6700 and 9900 cP at 6% w / w using spindle R4 at 100 rpm.

18. 20. The method of claim 19, wherein the CM-MFC has a crystallinity of 38-49%.

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