Process and system for forming particulate masterbatches and compositions obtained therefrom

Abstract

Improved processes and systems for forming masterbatches of particulates to be incorporated into polymers are disclosed. In some variations, the process of forming the particulate masterbatches includes the following steps: providing particulates; transferring the aqueous polymer latex and particulates to a mixing unit, thereby producing a particulate-latex mixture containing water; transferring the particulate-latex mixture to a homogenizer; transferring the homogenized particulate-latex mixture to a centrifuge to remove a first portion of the water; and then transferring the dewatered and homogenized particulate-latex mixture to a screw mixer configured to remove a second portion of the water, thereby producing a particulate masterbatch. Other variations employ polymer solids rather than polymer latex. The processes and systems provide higher energy efficiency, more robust operation with minimal process contamination, and excellent particulate dispersion in the masterbatch. These processes also do not require the use of latex coagulants.

Description

[Technical field]

[0001] Priority Data This international patent application claims priority to U.S. Provisional Patent Application No. 63 / 305,386, filed February 1, 2022, and U.S. Publication No. 18 / 103,454, filed January 30, 2023, each of which is incorporated by reference herein.

[0002] Field The present invention relates generally to processes and systems for forming masterbatches of particulates that can then be incorporated into various matrix materials, such as polymers. [Background technology]

[0003] background Particulate composites have many commercial applications and are of great importance worldwide. "Particulate composite" refers to a composite that includes a matrix material and finely divided particles suspended in the matrix material. The particles can significantly improve the strength, stiffness and toughness of the matrix material, which can be a polymer, ceramic material, or other type of matrix material. Particulate composites have been developed to achieve unusual combinations of properties (e.g., hardness, strength, thermal properties, corrosion resistance, etc.) that are typically not achievable with the matrix material alone.

[0004] A common example of a particulate composite is the combination of a nanoparticle and a polymer, which may combine, for example, the stiffness, dimensional stability, and thermal stability of an inorganic nanoparticle with the toughness, processability, chemical stability, and / or low cost of a polymer.

[0005] However, microparticle-filled polymeric materials prepared by simple blending typically do not work. One reason is that when the microparticle size is small (which is usually required to achieve the desired benefit), the microparticle surface energy is very large, which causes self-aggregation between the microparticles. On the other hand, if the mixture is inhomogeneous, it is difficult to completely eliminate the interfacial tension between the microparticles and the polymer matrix, which causes poor dispersion of the microparticles in the polymer. In order to avoid the agglomeration of the microparticles, it is usually desired that the microparticles are fine and well dispersed in the polymer matrix. One solution is what is commonly known as a masterbatch.

[0006] The use of particulate masterbatches has the potential to improve product consistency and process stability through better dispersion. Masterbatches are already premixed compositions in which the particulates are properly dispersed in the host resin, so masterbatches can alleviate the problems due to agglomeration or insufficient dispersion mentioned above. Masterbatches are typically used in polymer processing to incorporate color pigments and antimicrobial agents into polymer resins. Masterbatches are concentrated mixtures of additives encapsulated in a carrier material such as polyethylene or polypropylene. Masterbatches allow for more simplified dosing through pellet-to-pellet blending or dosing in the extruder. Special dosing equipment for trace amounts of additives is not required. Masterbatches also reduce the dosing precision required to achieve the same dosing rate in the final product.

[0007] Despite the aforementioned benefits of masterbatches, there remains a need for improved processes for forming particulate masterbatch compositions. Demands in the art include greater energy efficiency, more robust operation with minimal process fouling or plugging, and improved particulate dispersion in the masterbatch. Summary of the Invention [Problem to be solved by the invention]

[0008] In view of the foregoing demands in the art, improved processes and systems are needed for forming masterbatches of particulates for incorporation into polymers and other matrix materials. [Means for solving the problem]

[0009] overview In some variations, the present invention provides a process for forming a particulate masterbatch, the process comprising: (a) providing a plurality of particulates; (b) optionally introducing a plurality of particulates and a pH adjusting agent into a first mixing unit; (c) transferring the aqueous polymer latex and the plurality of microparticles from step (a) or, if performed, from step (b), to a second mixing unit, thereby producing a microparticle-latex mixture comprising water; (d) optionally transferring the particulate-latex mixture and the first process additive to a third mixing unit; (e) conveying the particulate-latex mixture to a homogenizer, thereby producing a homogenized particulate-latex mixture; (f) optionally, transferring the homogenized particulate-latex mixture to a centrifuge to remove a first portion of the water, thereby producing a dehydrated and homogenized particulate-latex mixture; and (g) transferring the dewatered and homogenized particulate-latex mixture (or the homogenized particulate-latex mixture from step (e), if step (f) has not been performed) to a screw mixer configured to remove a second portion of the water, thereby producing a particulate masterbatch. wherein steps (a), (c), (e), (f) and (g) are performed substantially sequentially.

[0010] If the process includes step (b) but not step (d), preferably steps (a)-(c) and then (e)-(g) are performed substantially sequentially. If the process includes step (d) but not step (b), preferably steps (a) and then steps (c)-(g) are performed substantially sequentially. If the process includes both steps (b) and (d), preferably steps (a)-(g) are performed substantially sequentially.

[0011] In some embodiments, at least one of the first mixing unit, the second mixing unit, and the third mixing unit is a static in-line mixer. In certain embodiments, at least two of the first mixing unit, the second mixing unit, and the third mixing unit are static in-line mixers. In a preferred embodiment, each of the first mixing unit, the second mixing unit, and the third mixing unit is a static in-line mixer. In a preferred embodiment, the second mixing unit utilized in step (c) is a static in-line mixer, regardless of whether steps (b) and (d) are employed.

[0012] An additional static in-line mixer may be located upstream of the first mixing unit in step (b) or upstream of the second mixing unit in step (c) to mix the different particulates. In some embodiments, the different particulates are first introduced into a premixing unit (i) prior to step (b), if performed, or (ii) prior to step (c). The premixing unit may be a static in-line premixer or other type of mixing unit.

[0013] In some embodiments, the plurality of particulates are first slurried prior to step (b). The slurried is carried out in a slurrying unit by adding water or other solvent for the particulates. The slurrying unit can be, but is not limited to, a simple vessel or tank equipped with an agitator, a homogenizer, a batch or in-line rotor-stator mixer, a kneader mixer, a co-rotating or counter-rotating paddle shaft mixer, an in-line tube static mixer, an eductor mixer, and the like.

[0014] In some embodiments, the centrifuge is a decanter centrifuge configured to remove a first portion of the water, thereby producing a dewatered and homogenized particulate-latex mixture.

[0015] In some embodiments, step (f) utilizes preheating of the homogenized particulate-latex mixture to facilitate water removal. Generally, it is preferred to utilize heat in step (f) to facilitate water removal.

[0016] In some embodiments, the screw mixer is a screw extruder, such as (but not limited to) a twin screw extruder, which may be configured with multiple extruder zones with independent temperature control, and / or multiple suction vents to facilitate removal of the second portion of water, and / or one or more side feeders to add chemicals such as process additives. In some embodiments, the screw mixer is a twin rotor mixer.

[0017] The process may include introducing a process additive into any step of the process.

[0018] The process may be continuous, semi-continuous, batch or semi-batch. Preferably, the process is substantially continuous.

[0019] In some processes, the particulate masterbatch is characterized by a dispersion index of at least 50, preferably at least 75, and more preferably at least 90.

[0020] In some preferred embodiments, the process does not employ a polymeric latex coagulant.

[0021] The plurality of particulates can include, for example, biomass-derived particulates selected from the group consisting of cellulose, nanocellulose, hemicellulose, nanohemicellulose, lignin, nanolignin, nanolignocellulose, and combinations thereof.

[0022] The plurality of particulates may include, for example, particulates selected from the group consisting of silica, alumina, clay, nanoclay, zeolite, ceramic, metal, glass, polymer, and combinations thereof.

[0023] The plurality of particulates may include, for example, carbonaceous particulates selected from the group consisting of carbon black, graphite, graphene, activated carbon, carbon nanotubes, carbon fibers, biochar, coke, nanodiamonds, and combinations thereof.

[0024] In some embodiments, the microparticles comprise or consist essentially of nanocellulose, while in other embodiments, the microparticles do not comprise nanocellulose.

[0025] In some embodiments, the particulate comprises or consists essentially of carbon black, hi other embodiments, the particulate does not comprise carbon black.

[0026] In some embodiments, there are at least two types of particulates. In these embodiments, at least one type of particulate may be slurried prior to step (b). Both types of particulates may be slurried in separate slurrying units and then combined, or they may be slurried together, or a combination thereof.

[0027] In some embodiments, the particulates comprise or consist essentially of nanocellulose and carbon black, while in other embodiments, the particulates comprise neither nanocellulose nor carbon black.

[0028] In some variations, the present invention provides a method for producing a method of making a semiconductor device comprising: (a) providing a plurality of particulates; (b) optionally introducing a plurality of particulates and a pH adjusting agent into a first mixing unit; (c) transferring the aqueous polymer latex and the plurality of microparticles from step (a) or, if performed, from step (b), to a second mixing unit, thereby producing a microparticle-latex mixture comprising water; (d) optionally transferring the particulate-latex mixture and the first process additive to a third mixing unit; (e) conveying the particulate-latex mixture to a homogenizer, thereby producing a homogenized particulate-latex mixture; (f) optionally, transferring the homogenized particulate-latex mixture to a centrifuge to remove a first portion of the water, thereby producing a dehydrated and homogenized particulate-latex mixture; and (g) transferring the dewatered and homogenized particulate-latex mixture (or the homogenized particulate-latex mixture from step (e), if step (f) has not been performed) to a screw mixer configured to remove a second portion of the water, thereby producing a particulate masterbatch. wherein steps (a), (c), (e), (f) and (g) are performed substantially sequentially.

[0029] In some variations, the present invention provides a system for forming a particulate masterbatch, the system comprising: (a) providing a plurality of particulates; (b) optionally introducing a plurality of particulates and a pH adjusting agent into a first mixing unit; (c) transferring the aqueous polymer latex and the plurality of microparticles from step (a) or, if performed, from step (b), to a second mixing unit, thereby producing a microparticle-latex mixture comprising water; (d) optionally transferring the particulate-latex mixture and the first process additive to a third mixing unit; (e) conveying the particulate-latex mixture to a homogenizer, thereby producing a homogenized particulate-latex mixture; (f) optionally, transferring the homogenized particulate-latex mixture to a centrifuge to remove a first portion of the water, thereby producing a dehydrated and homogenized particulate-latex mixture; and (g) transferring the dewatered and homogenized particulate-latex mixture (or the homogenized particulate-latex mixture from step (e), if step (f) has not been performed) to a screw mixer configured to remove a second portion of the water, thereby producing a particulate masterbatch. wherein steps (a), (c), (e), (f) and (g) are performed substantially sequentially.

[0030] In some variations, the present invention provides a system for forming a particulate masterbatch, the system comprising: (i) optionally, a first mixing unit configured to mix a plurality of particulates and a pH adjusting agent; (ii) a second mixing unit in fluid communication with the first mixing unit (if present), the second mixing unit configured to mix the plurality of microparticles and the aqueous polymer latex; (iii) optionally, a third mixing unit in fluid communication with the second mixing unit, the third mixing unit configured to mix the particulate-latex mixture and one or more process additives; (iv) a homogenizer in fluid communication with the third mixing unit, if present, or the second mixing unit, the homogenizer configured to produce a homogenized particulate-latex mixture; (v) optionally, a centrifuge in fluid communication with the homogenizer, the centrifuge configured to remove a first portion of the water, thereby producing a dewatered and homogenized particulate-latex mixture; and (vi) a screw mixer in fluid communication with the centrifuge (or homogenizer if the centrifuge is omitted), the screw mixer configured to remove a second portion of the water, thereby producing a particulate masterbatch; and (vii) A discharge section for recovering the fine particle master batch. Equipped with.

[0031] Other variations of the present invention utilize polymer solids rather than or in addition to the polymer latex.

[0032] Some variations provide a process for forming a particulate masterbatch, the process comprising: (a) providing a plurality of particulates in the form of a particulate slurry comprising water; (b) optionally introducing the particulate slurry and a first process additive into a first mixing unit, the first process additive comprising a pH adjuster; (c) optionally transferring the particulate slurry and a second process additive to a second mixing unit; (d) optionally, transferring the particulate slurry to a homogenizer; (e) optionally, transferring the particulate slurry to a centrifuge to remove a first portion of the water; (f) transferring the particulate slurry, polymer solids, and optionally a third process additive to a screw mixer configured to remove a second portion of the water, thereby producing a particulate masterbatch. wherein step (a), any of steps (b) through (e), and step (f) are performed substantially sequentially.

[0033] In some embodiments, steps (b), (c), (d) and (e) are performed, and steps (a)-(f) are performed substantially sequentially. In certain embodiments, one or two of steps (b), (c), (d) and (e) are performed, and all process steps are performed substantially sequentially. In certain embodiments, step (b) is performed.

[0034] In some embodiments, the first mixing unit is a first static in-line mixer. In these or other embodiments, the second mixing unit is a second static in-line mixer.

[0035] In some embodiments, the plurality of particulates is first introduced into a premix unit prior to step (b), for example, the plurality of particulates may be slurried with water in a premix unit, which may be referred to as a slurrying unit when a slurry is formed.

[0036] In some embodiments employing step (e), the centrifuge is a decanter centrifuge.

[0037] The second process additive can be a compatibilizer that compatibilizes the particulate with the polymer solids. Alternatively, or in addition, the third process additive can be a compatibilizer that compatibilizes the particulate with the polymer solids. The third process additive can be transferred directly to the screw mixer through an inlet port or can be added to the input stream introduced into the screw mixer.

[0038] In some embodiments, step (f) utilizes heating to facilitate removal of water from the screw mixer. Optionally, preheating is performed during or prior to step (f) to preheat the particulate slurry to facilitate removal of water from the screw mixer.

[0039] In some embodiments, the screw mixer is a twin screw extruder. The twin screw extruder may be configured with multiple extruder zones that are independently temperature controlled and multiple suction vents that facilitate removal of the second portion of water. In other embodiments, the screw mixer is a twin rotor mixer.

[0040] In some embodiments, the process is continuous or semi-continuous, while in other embodiments, the process is batch or semi-batch.

[0041] The particulate masterbatch may be characterized by a dispersion index of at least 50, at least 75, or at least 90, for example.

[0042] Preferably, the process does not employ a polymeric latex coagulant.

[0043] The plurality of particulates may comprise at least two types of particulates, where at least one type of particulate is slurried prior to step (b).

[0044] In some embodiments, the plurality of particulates comprises biomass-derived particulates selected from the group consisting of cellulose, nanocellulose, hemicellulose, nanohemicellulose, lignin, nanolignin, nanolignocellulose, and combinations thereof.

[0045] In some embodiments, the plurality of particulates comprises particulates selected from the group consisting of silica, alumina, clay, nanoclay, zeolite, ceramic, metal, glass, polymer, and combinations thereof.

[0046] In some embodiments, the plurality of particulates comprises carbonaceous particulates selected from the group consisting of carbon black, graphite, graphene, activated carbon, carbon nanotubes, carbon fibers, biochar, coke, nanodiamonds, and combinations thereof.

[0047] In certain embodiments, the microparticles comprise nanocellulose. In various embodiments, the microparticles do not comprise nanocellulose.

[0048] In certain embodiments, the particulate comprises carbon black. In various embodiments, the particulate does not comprise carbon black.

[0049] In certain embodiments, the particulate comprises nanocellulose and carbon black, hi other embodiments, the particulate does not comprise either nanocellulose or carbon black.

[0050] In some variations, the present invention provides a method for producing a method of making a semiconductor device comprising: (a) providing a plurality of particulates in the form of a particulate slurry comprising water; (b) optionally introducing the particulate slurry and a first process additive into a first mixing unit, the first process additive comprising a pH adjuster; (c) optionally transferring the particulate slurry and a second process additive to a second mixing unit; (d) optionally, transferring the particulate slurry to a homogenizer; (e) optionally, transferring the particulate slurry to a centrifuge to remove a first portion of the water; (f) transferring the particulate slurry, polymer solids, and optionally a third process additive to a screw mixer configured to remove a second portion of the water, thereby producing a particulate masterbatch. wherein step (a), any of steps (b)-(e), and step (f) are carried out substantially sequentially.

[0051] In some variations, the present invention provides a system for forming a particulate masterbatch, the system comprising: (a) providing a plurality of particulates in the form of a particulate slurry comprising water; (b) optionally introducing the particulate slurry and a first process additive into a first mixing unit, the first process additive comprising a pH adjuster; (c) optionally transferring the particulate slurry and a second process additive to a second mixing unit; (d) optionally, transferring the particulate slurry to a homogenizer; (e) optionally, transferring the particulate slurry to a centrifuge to remove a first portion of the water; (f) transferring the particulate slurry, polymer solids, and optionally a third process additive to a screw mixer configured to remove a second portion of the water, thereby producing a particulate masterbatch. wherein step (a), any of steps (b)-(e), and step (f) are performed substantially sequentially.

[0052] In some variations, the present invention provides a system for forming a particulate masterbatch, the system comprising: (i) optionally a first mixing unit configured to mix a plurality of particulates and a pH adjuster (as a first process additive); (ii) optionally, a second mixing unit in flow communication with the first mixing unit, the second mixing unit configured to mix the plurality of particulates with a second process additive; (iii) optionally, a homogenizer in fluid communication with the second mixing unit, if present, or with the first mixing unit; (iv) optionally, a centrifuge in fluid communication with the homogenizer, if present, or with the second mixing unit, if present, or with the first mixing unit, the centrifuge configured to remove a first portion of the water; (v) a screw mixer in fluid communication with the centrifuge (or the homogenizer if the centrifuge is omitted, or the second mixing unit if the homogenizer is omitted, or the first mixing unit if the second mixing unit is omitted), the screw mixer configured to remove a second portion of the water, thereby generating a particulate masterbatch; and (vi) A discharge section for recovering the fine particle master batch. Equipped with. [Brief description of the drawings]

[0053] BRIEF DESCRIPTION OF THE DRAWINGS [Figure 1] 1 is an exemplary block-flow diagram illustrating the process and system of the present invention using a polymer latex in some embodiments. The dotted lines and boxes indicate optional streams and units, respectively. [Diagram 2] 2 is an exemplary block-flow diagram illustrating the process and system of the present invention using a polymer latex in certain embodiments. The dotted lines and boxes indicate optional streams and units, respectively. [Diagram 3] 3 is an exemplary block-flow diagram illustrating the process and system of the present invention using polymer solids in certain embodiments. The dotted lines and boxes indicate optional streams and units, respectively. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0054] Detailed Description of the Invention The description enables one skilled in the art to make and use the invention and describes numerous embodiments, adaptations, variations, alternatives, and uses of the present invention. These and other embodiments, features, and advantages of the present invention will become apparent to those skilled in the art upon review of the following detailed description of the invention in conjunction with any accompanying drawings.

[0055] As used in this specification and the appended claims, the singular forms "a", "an" and "the" include plural references unless the context clearly dictates otherwise. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. All composition numbers and ranges based on percentages are percent by weight unless otherwise specified. All ranges relating to numerical values ​​or conditions are meant to include any particular value included within the range, rounded to any suitable decimal point.

[0056] Unless otherwise indicated, all numbers expressing parameters, reaction conditions, concentrations of ingredients, and the like used in the specification and claims are to be understood as being modified in all instances by the term "about." Accordingly, unless otherwise indicated, the numerical parameters set forth in the following specification and appended claims are approximations that may vary depending at least on particular analytical techniques.

[0057] The term "comprising," which is synonymous with "including," "containing," or "characterized by," is inclusive or open-ended and does not exclude additional, unrecited elements or method steps. "Comprising" is a term of art used in claim language to mean that a recited claim element is essential, but that other claim elements may be added and still form a structure within the scope of the claim.

[0058] As used herein, the phrase "consisting of" excludes any element, step, or ingredient not specified in the claim. When the phrase "consist of" (or variations thereof) appears in a clause in the body of a claim rather than immediately following the preamble, it limits only the elements set forth in that clause; other elements are not excluded from the claim as a whole. As used herein, the phrase "consisting essentially of" limits the claim to the specified elements or method steps, plus those that do not materially affect the basic and novel characteristics of the claimed subject matter.

[0059] With respect to the terms "comprising," "consisting of," and "consisting essentially of," when one of these three terms is used herein, the disclosed and claimed subject matter may include the use of either of the other two terms. Thus, in some embodiments where not otherwise stated, any instance of "comprising" may be replaced by "consisting of" or alternatively by "consisting essentially of."

[0060] Exemplary embodiments of the invention are described herein. These embodiments are not intended to limit the scope of the invention as claimed. References herein to a first step, a second step, etc. are merely for the purpose of illustrating some embodiments. Also, unless otherwise specified, the location of a step or unit may vary at one or more sites. Also, it should be understood that all references to "embodiments" are open-ended and should be construed as an option for any other disclosed embodiment unless the context clearly dictates otherwise. In the drawings, dotted lines indicate any unit operation or flow.

[0061] The present invention generally relates to processes and systems for producing masterbatches, such as composite elastomeric masterbatches for incorporation into rubber systems. In various embodiments, the benefits of the present invention include excellent particulate dispersion in the masterbatch, energy efficiency, robust operation with minimal process fouling or plugging, and elimination of coagulants. The processes, systems, and principles of the present invention are based on extensive laboratory and pilot-scale process development.

[0062] Masterbatch processes using aqueous polymer latexes and particulates can provide homogeneous dispersions and better end-use performance compared to kneading or simple extrusion. However, there are technical challenges associated with processing, blending, dewatering and drying the latex elastomers and particulates (in dry powder or aqueous slurry form) for homogeneous dispersion in the end-use polymer product.

[0063] For example, when nanocellulose and / or carbon black are used as particulates, the beneficial properties of the particulates in the end-use product are significantly enhanced by the enhanced dispersion and reduced agglomeration in the rubber product. A masterbatch with good pre-dispersion of the particulates is necessary for optimal dispersion in the final material.

[0064] A number of known challenges with masterbatch processing of latex slurries include agglomeration and rapid plugging / fouling during pumping and mixing, especially when multiple mixing steps are required for optimal dispersion or when multiple components are added to the slurry in stages.

[0065] Conventional latex masterbatch processes also include the use of latex coagulants and separation of the macrocoagulants from the free water prior to drying. Disadvantages of coagulation include (a) the use of salts and acids whose residues are undesirable in the end-use product, and (b) the adverse effect on particulate dispersion between latex particles during coagulum.

[0066] In this disclosure, "polymer latex" refers to a stable colloidal dispersion of polymer particles in a liquid, such as water. The polymer particles can be nanoparticles, microparticles, or a combination thereof. Aqueous polymer latex is a common embodiment in which the polymer particles form a colloidal dispersion in water or a solution that includes water. In other embodiments, the polymer latex forms a colloidal dispersion in an organic solvent or an inorganic solvent other than water.

[0067] One example of a polymer latex is natural rubber latex, which is a natural colloidal dispersion of cis-poly(isoprene) in a water-rich liquid. In addition to the cis-poly(isoprene) particles and water, unless refined, natural rubber latex contains small amounts of proteins, sterol glycosides, resins, disodium, and sugars.

[0068] In some variations, the present invention provides a process for forming a particulate masterbatch, the process comprising: (a) providing a plurality of particulates; (b) optionally introducing a plurality of particulates and a pH adjusting agent into a first mixing unit; (c) transferring the aqueous polymer latex and the plurality of microparticles from step (a) or, if performed, from step (b), to a second mixing unit, thereby producing a microparticle-latex mixture comprising water; (d) optionally transferring the particulate-latex mixture and the first process additive to a third mixing unit; (e) conveying the particulate-latex mixture to a homogenizer, thereby producing a homogenized particulate-latex mixture; (f) optionally (but preferably), transferring the homogenized particulate-latex mixture to a centrifuge to remove a first portion of the water, thereby producing a dehydrated and homogenized particulate-latex mixture; and (g) transferring the dewatered and homogenized particulate-latex mixture (or the homogenized particulate-latex mixture from step (e), if step (f) has not been performed) to a screw mixer configured to remove a second portion of the water, thereby producing a particulate masterbatch. wherein steps (a), (c), (e), (f) and (g) are performed substantially sequentially.

[0069] When step (b) but not step (d) is included in the process, preferably steps (a)-(c) and then (e)-(g) are performed substantially sequentially (step (f) is optionally omitted). When step (d) but not step (b) is included in the process, preferably steps (a) and then steps (c)-(g) are performed substantially sequentially. When both steps (b) and (d) are included in the process, preferably steps (a)-(g) are performed substantially sequentially. In the present disclosure, "substantially sequentially" means that the main process flow is sequential and the steps are performed in order, it being understood that there may be various recycle streams, purge streams, addition streams, etc.

[0070] To prevent agglomeration of the polymer latex and to minimize equipment costs, static in-line mixers are utilized in preference to other mixing devices, including in-line rotor-stator mixers. In some embodiments, at least one of the first mixing unit, the second mixing unit, and the third mixing unit is a static in-line mixer. In certain embodiments, at least two of the first mixing unit, the second mixing unit, and the third mixing unit are static in-line mixers. In preferred embodiments, each of the first mixing unit, the second mixing unit, and the third mixing unit is a static in-line mixer. In preferred embodiments, the second mixing unit utilized in step (c) is a static in-line mixer, regardless of whether steps (b) and (d) are employed.

[0071] An additional static in-line mixer may be located upstream of the first mixing unit in step (b) or upstream of the second mixing unit in step (c) to mix the multiple types of particulates. In some embodiments, the multiple particulates are first introduced into a premixing unit (i) prior to step (b) if performed, or (ii) prior to step (c). The premixing unit may be a static in-line premixer or other type of mixing unit.

[0072] As shown in Figures 1 and 2, the particulates may first be slurried prior to feeding the particulates to the first mixing unit. Slurrying may be done using water (typical), an aqueous liquid, a non-aqueous liquid, or a combination thereof. The slurrying unit may be, but is not limited to, a simple vessel or tank equipped with an agitator, a homogenizer, a batch or in-line rotor-stator mixer, a kneader mixer, a co-rotating or counter-rotating paddle shaft mixer, an in-line tube static mixer, an eductor mixer, and the like.

[0073] A variety of particulates can be used to generate the particulate masterbatch. Exemplary particulates include, but are not limited to, nanocellulose, carbon black, carbon fiber, graphite, activated carbon, biochar, pyrolytic biomass, lignin-derived carbon, lignin, silica, alumina, clay, nanoclay, ceramic, polymer-derived ceramic, glass fiber, zeolite, cellulose fiber, polymer fiber, pyrolytic polymer, graphene, carbon nanotubes, and nanodiamonds.

[0074] The particulates may be fed to the process as a fine powder (which may be a dry or wet powder), as fibers, as pellets, as a slurry in a solvent or liquid carrier (e.g., water), or as a combination thereof. If the particulates are fed as a slurry, the particulates may be about, at least about, or up to about 1, 5, 10, 15, 20, 25, 30, 40, 50, 60, 70, 80, 90, 95, 99, 99.5, or 99.9% solids (particulates) by weight, including any range therebetween.

[0075] The microparticles may be characterized by an average particle size of, for example, about 1 nanometer to about 100 microns. For non-spherical particles, the average particle size is the average effective diameter of the particle. In various embodiments, the microparticles are characterized by an average particle size of about, at least about, or at most about 1 nm, 5 nm, 10 nm, 15 nm, 20 nm, 25 nm, 50 nm, 75 nm, 100 nm, 200 nm, 300 nm, 400 nm, 500 nm, 600 nm, 700 nm, 800 nm, 900 nm, 1 μm, 2 μm, 3 μm, 4 μm, 5 μm, 10 μm, 15 μm, 20 μm, 25 μm, 30 μm, 40 μm, 50 μm, 60 μm, 70 μm, 80 μm, 90 μm, or 100 μm, including any range therebetween.

[0076] Particle size can be measured by a variety of techniques including, for example, dynamic light scattering, laser diffraction, image analysis, or separation by sieving. Dynamic light scattering is a non-destructive and well-established technique for measuring particle size and size distribution in the sub-micron range, typically down to 1 nanometer in state-of-the-art technology. Laser diffraction is a widely used particle classification technique for materials in the size range from hundreds of nanometers to several millimeters. Exemplary dynamic light scattering and laser diffraction instruments for measuring particle size are available from Malvern Instruments Ltd., Worcestershire, UK. Image analysis to estimate particle size and distribution can be performed directly on photomicrographs, scanning electron micrographs, or other images. Finally, sieving is a conventional technique for separating particles by size.

[0077] The microparticles can have virtually any shape, including spheres, cubes, polygons, rods, needles, fibers, plates, sheets, or irregular geometric shapes.

[0078] The particulates are in the solid phase when fed to the masterbatch process, and the particulates are in the solid phase in the masterbatch product. In principle, some melting, softening or dissolution of the particulates may occur during the process, such as in the extruder.

[0079] The solid and liquid content of the polymer latex may vary widely, such as from about 10% liquid by weight to about 99.9% liquid by weight, in various embodiments, the polymer latex is about, at least about, or up to about 10, 15, 20, 25, 30, 40, 50, 60, 70, 80, 90, 95, 99, 99.5, or 99.9% liquid (e.g., water) by weight, including any range therebetween.

[0080] The pH adjuster (referred to as "pH Agent" in FIG. 1) can vary depending on the desired pH in the masterbatch process. The pH adjuster can be, for example, an acid, a base, a salt, or a buffer. In an exemplary embodiment, the pH adjuster is sodium hydroxide.

[0081] Optional process additives may be added at any time during one or more steps of the process. The process additives may be solvents, carriers, acids, bases, buffers, stabilizers, surfactants, emulsifiers, compatibilizers, antioxidants, flame retardants, nucleating agents, pesticides, herbicides, bacteriocides, viral inactivators, density modifiers, viscosity modifiers, colorants, texturizing agents, diluents, fillers, different types of particulates (i.e., different from the particulates fed), or combinations thereof. Figures 1 and 2 show that the process additives are introduced into the third mixing unit. The process additives may be added elsewhere, including to the starting particulates or the final masterbatch product. In one example, the compatibilizer is added to the screw mixer or upstream of the screw mixer.

[0082] Exemplary process additives are treated distillate aromatic extract (TDAE) oil, distillate aromatic extract (DAE) oil, mild extract solvate (MES), residual aromatic extract (RAE), residual aromatic extract (TRAE), naphthenic plasticizer (NAP), or combinations thereof. In Figure 2, TDAE is, for example, a process additive added to the third in-line mixer.

[0083] Homogenizers are used to obtain the blending of the aqueous mixture of latex and particulates for optimal pre-dispersion in the masterbatch and eventual dispersion in the end-use product. A "homogenizer" utilizes mechanical force, such as shearing the material through small openings under high pressure. The homogenizer may reduce the particle size of the polymer (in the polymer latex) to achieve better dispersion. In certain embodiments, the homogenizer may also reduce the size of the particulates. As shown in Figures 1, 2 and 3 (optional), multiple passes through the homogenizer may be used to achieve the desired particle size and / or dispersion index of the masterbatch.

[0084] In some embodiments, step (f) utilizes preheating of the homogenized particulate-latex mixture to facilitate water removal. Generally, it is preferred in step (f) to utilize heating to facilitate water removal from the centrifuge.

[0085] A centrifuge is preferably included in the process. It is possible to omit the centrifuge and transfer the homogenized material directly to a screw mixer, but the energy requirements, and therefore operating costs, would generally be significantly higher.

[0086] In some embodiments, the centrifuge is a decanter centrifuge configured to remove a first portion of the water, thereby producing a dewatered and homogenized particulate-latex mixture. A continuous decanter centrifuge with feed preheating is preferably employed to dewater ingredients combined to a relatively high solids content, such as from about 10% solids by weight to about 50% solids by weight, e.g., from about 30% solids by weight to about 40% solids by weight. The configuration of the decanter centrifuge upstream of the extruder (or other screw mixer) limits the energy required for the removal of water by heat in the extruder.

[0087] In some embodiments, the screw mixer is a screw extruder, such as, but not limited to, a twin screw extruder. The twin screw extruder may be configured with multiple extruder zones with independent temperature control, and / or multiple suction vents to facilitate removal of the second portion of the water, and / or one or more side feeders to add chemicals such as process additives. In some embodiments, the screw mixer is a twin rotor mixer.

[0088] In certain embodiments, the twin screw extruder includes multiple extruder zones with each zone having an independently controlled temperature for optimal thermal dehydration. Multiple suction vents may be located along the length of the extruder to release water vapor. Although Figures 1 and 2 suggest three suction vents, there may be zero, one, two, three, four, five or more suction vents. The suction vents may be configured with a fill screw to prevent solids from being removed along with the water vapor. Individual segments of the extruder screw are preferably designed for dehydration / steam removal, shearing and transport.

[0089] In some embodiments, the twin screw extruder includes a single side feeder for adding chemicals such as process additives (e.g., compatibilizers). In certain embodiments, the twin screw extruder includes multiple side feeders for adding chemicals such as process additives, which may be the same in each side feeder or may be different in different side feeders. Multiple side feeders may be positioned along the length of the extruder for adding chemicals. The side feeders are typically ports that are different from the suction vents previously described in the paragraph above.

[0090] When the screw mixer is a screw extruder, the extruder exit die may be designed according to the desired physical form of the masterbatch. Exemplary masterbatch forms include, but are not limited to, pellets, prills, strands, crumbs, or thin sheets or slabs.

[0091] In a preferred embodiment, the process does not employ a polymeric latex coagulant. Examples of polymeric latex coagulants include organic acids such as citric acid, acetic acid, formic acid, or glycolic acid; inorganic acids such as sulfuric acid, nitric acid, phosphoric acid, hydrochloric acid; and / or salts of any of the foregoing.

[0092] In a preferred embodiment, the process avoids coagulation of the polymer latex. One skilled in the art will understand the importance of pump selection, piping configuration, and order of addition of components to prevent latex agglomeration. By avoiding latex coagulation, the polymer and particulates remain well dispersed.

[0093] The plurality of particulates may include, for example, a biomass-derived particulate selected from the group consisting of cellulose, nanocellulose, hemicellulose, nanohemicellulose, lignin, nanolignin, nanolignocellulose, and combinations thereof. Nanocellulose is described in more detail later in this specification. Nanolignin refers to lignin having a particle size of 1000 nanometers or less. Nanohemicellulose refers to hemicellulose oligomers having a particle size of 1000 nanometers or less.

[0094] The plurality of particulates may include, for example, particulates selected from the group consisting of silica, alumina, clay, nanoclay, zeolite, ceramic (e.g., silicon carbide), mineral (e.g., calcium carbonate, wollastonite, mica, kaolin, bentonite, biotite, or illite), metal (e.g., nickel), metal alloy (e.g., aluminum alloy), metal oxide (e.g., iron oxide), glass (e.g., glass fiber or glass beads), polymer (e.g., polymer fibers), pyrolyzed polymer (e.g., pyrolysis waste PET), polymer-derived ceramic (via pyrolysis of preceramic polymers), and combinations thereof.

[0095] The plurality of particulates may include, for example, carbonaceous particulates selected from the group consisting of carbon black, graphite, graphene, activated carbon, carbon nanotubes, carbon fibers, biochar, coke, nanodiamonds, and combinations thereof.

[0096] In some embodiments, the microparticles comprise or consist essentially of nanocellulose. In other embodiments, the microparticles do not comprise nanocellulose. Nanocellulose is described in more detail herein below.

[0097] In some embodiments, the particulate comprises or consists essentially of carbon black. In other embodiments, the particulate does not comprise carbon black. Carbon black is a commercially available form of solid carbon, produced in a highly controlled process that produces specifically engineered agglomerates of carbon particles that differ in particle size, agglomerate size, shape, porosity, and surface chemistry. There are many known types of carbon black, including acetylene black, channel black, furnace black, lamp black, thermal black, recycled carbon black, graphitized carbon black, functionalized carbon black, and the like.

[0098] In some embodiments, the particulates comprise or consist essentially of nanocellulose and carbon black, while in other embodiments, the particulates comprise neither nanocellulose nor carbon black.

[0099] FIG. 2 shows an embodiment in which nanocellulose particulates as well as silica particulates are used. In FIG. 2, the silica is first slurried with water, after which the silica can be added to an optional in-line premixer. The nanocellulose will typically be added in the form of an aqueous slurry. In certain embodiments, the silica is slurried with a dilute slurry of nanocellulose, with excess water acting as a carrier for the silica. In such variations, some or all of the nanocellulose will be added to the slurrying unit in FIG. 2.

[0100] In some processes, the particulate masterbatch is characterized by a dispersion index of at least 50, preferably at least 75, and more preferably at least 90. In various embodiments, the particulate masterbatch is characterized by a dispersion index of about or at least about 50, 55, 60, 65, 70, 75, 80, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, or 95, including any range therebetween (e.g., 80-93).

[0101] There are many different techniques that can be used to measure or estimate the dispersion index, including optical microscopy, profilometry, optical properties, electrical resistivity, reflectance measurements, etc. A traditional technique for characterizing the dispersion of particulates is the analysis of thin sections by optical microscopy. See, for example, ASTM D2663 part B.5, which is incorporated herein by reference. The dispersion index can be calculated according to the formulas set forth in Leigh-Dugmore, "Measurement of Dispersion in Black-Loaded Rubber", RUBBER CHEM. TECHNOL. 29, 1303 (1956), and Medalia, "Dispersion of Carbon Black in Rubber: Revised Calculation Procedure", RUBBER CHEM. TECHNOL. 34, 1134 (1961), where it is understood that the particulates do not necessarily have to be carbon black, but can be many other types of particulates.

[0102] The technique of interference microscopy can be used for dispersion characterization. Interference microscopy has the advantages of being fast, simple, and quantitative. Interference microscopy uses interference fringes between an in-phase beam reflected from a sample and a smooth reference surface to measure three-dimensional surface topography. Peaks and valleys present on the freshly cut surface represent particulate agglomerates and are used to characterize the dispersion. A series of samples with different base particulate complexes and various levels of dispersion can be formed and characterized by both optical and interference microscopy.

[0103] The process may be continuous, semi-continuous, batch or semi-batch. Preferably, the process is substantially continuous.

[0104] FIG. 1 is an exemplary block-flow diagram illustrating the process and system of the present invention in some embodiments. The dashed lines and boxes indicate optional streams and units, respectively. In FIG. 1, an optional slurry unit is provided to combine the particulates with water (or other solvent).

[0105] FIG. 2 is an exemplary block-flow diagram illustrating the process and system of the present invention in certain embodiments. The dotted lines and boxes indicate optional streams and units, respectively. In FIG. 2, "caustic" refers to an alkaline additive that increases the pH, where the alkaline additive can be sodium hydroxide or other alkaline additives. In FIG. 2, an optional slurrying unit is provided that combines the silica particulates with water (or other solvent). Nanocellulose can also be fed to the same slurrying unit, or to another slurrying unit if desired, or fed directly to an in-line premixer (if present) or to the first in-line mixer.

[0106] It should be noted that the embodiments of Figures 1 and 2 assume the use of a water-based polymer latex, with the removal of water at some point in the process being shown. In other embodiments, the polymer latex may utilize a liquid other than water, in which case "water" is replaced with "liquid" in these figures. One example of a liquid other than water is ethanol or other alcohol.

[0107] In some variations, the present invention provides a method for producing a method of making a semiconductor device comprising: (a) providing a plurality of particulates; (b) optionally introducing a plurality of particulates and a pH adjusting agent into a first mixing unit; (c) transferring the aqueous polymer latex and the plurality of microparticles from step (a) or, if performed, from step (b), to a second mixing unit, thereby producing a microparticle-latex mixture comprising water; (d) optionally transferring the particulate-latex mixture and the first process additive to a third mixing unit; (e) conveying the particulate-latex mixture to a homogenizer, thereby producing a homogenized particulate-latex mixture; (f) optionally, transferring the homogenized particulate-latex mixture to a centrifuge to remove a first portion of the water, thereby producing a dehydrated and homogenized particulate-latex mixture; and (g) transferring the dewatered and homogenized particulate-latex mixture (or the homogenized particulate-latex mixture from step (e), if step (f) has not been performed) to a screw mixer configured to remove a second portion of the water, thereby producing a particulate masterbatch. wherein steps (a), (c), (e), (f) and (g) are carried out substantially sequentially.

[0108] The particulate master batch product may contain, for example, about 0.1% by weight of particulates to about 90% by weight of particulates. Typically, the particulate master batch product contains about 10% by weight of particulates to about 50% by weight of particulates. In various embodiments, the particulate master batch product contains about, at least about, or up to about 1, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 60, 70, 80, or 90% by weight of particulates, including any range therebetween.

[0109] The particulate masterbatch product may contain, for example, from about 10% by weight particulate to about 99.9% by weight polymer (from the starting polymer latex). In various embodiments, the particulate masterbatch product contains about, at least about, or up to about 10, 15, 20, 25, 30, 35, 40, 45, 50, 60, 70, 80, 90, or 95% by weight polymer, including any range therebetween.

[0110] The particulate masterbatch product may be completely dry or may contain some moisture (typically water, but can be other liquids). In various embodiments, the particulate masterbatch product contains about or up to about 0, 0.1, 0.2, 0.3, 0.4, 0.5, 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10% water by weight, including any range therebetween.

[0111] The particulate masterbatch product may be in the form of, for example, dry powder, wet powder, pellets, prills, strands, granules, crumbs, chips, or thin sheets or slabs. The extruder outlet (e.g., extruder die) may be designed for the intended masterbatch product form. A compounding device may be provided that is configured to produce a particulate masterbatch product in powder form.

[0112] In certain embodiments, a liquid solvent is added to form a liquid masterbatch product that may be desirable for certain applications. The liquid solvent may be a polar liquid solvent, for example, selected from the group consisting of water, C1-C8 alcohols, C2-C8 polyols, and combinations thereof. Additionally or alternatively, non-polar liquid solvents such as aromatic hydrocarbons, for example, toluene, xylene, or lignin derivatives may be used.

[0113] In some variations, the present invention provides a system for forming a particulate masterbatch, the system comprising: (a) providing a plurality of particulates; (b) optionally introducing a plurality of particulates and a pH adjusting agent into a first mixing unit; (c) transferring the aqueous polymer latex and the plurality of microparticles from step (a) or, if performed, from step (b), to a second mixing unit, thereby producing a microparticle-latex mixture comprising water; (d) optionally transferring the particulate-latex mixture and the first process additive to a third mixing unit; (e) conveying the particulate-latex mixture to a homogenizer, thereby producing a homogenized particulate-latex mixture; (f) optionally, transferring the homogenized particulate-latex mixture to a centrifuge to remove a first portion of the water, thereby producing a dehydrated and homogenized particulate-latex mixture; and (g) transferring the dewatered and homogenized particulate-latex mixture (or the homogenized particulate-latex mixture from step (e), if step (f) has not been performed) to a screw mixer configured to remove a second portion of the water, thereby producing a particulate masterbatch. wherein steps (a), (c), (e), (f) and (g) are performed substantially sequentially.

[0114] In some variations, the present invention provides a system for forming a particulate masterbatch, the system comprising: (i) optionally, a first mixing unit configured to mix a plurality of particulates and a pH adjusting agent; (ii) a second mixing unit in fluid communication with the first mixing unit (if present), the second mixing unit configured to mix the plurality of microparticles and the aqueous polymer latex; (iii) optionally, a third mixing unit in fluid communication with the second mixing unit, the third mixing unit configured to mix the particulate-latex mixture and one or more process additives; (iv) a homogenizer in fluid communication with the third mixing unit, if present, or the second mixing unit, the homogenizer configured to produce a homogenized particulate-latex mixture; (v) optionally, a centrifuge in fluid communication with the homogenizer, the centrifuge configured to remove a first portion of the water, thereby producing a dewatered and homogenized particulate-latex mixture; and (vi) a screw mixer in fluid communication with the centrifuge (or homogenizer if no centrifuge is present), the screw mixer configured to remove a second portion of the water, thereby producing a particulate masterbatch; and (vii) A discharge section for recovering the fine particle master batch. Includes.

[0115] Other variations of the invention utilize polymer solids rather than or in addition to a polymer latex. As used herein, "polymer solids" refers to substantially solid materials that contain one or more polymers and are not in the form of a polymer emulsion, polymer slurry, or polymer dissolved in a solvent. By "substantially solid" is meant that the polymer solids may contain 10% or less by weight of water and / or other liquids. Preferably, the polymer solids contain 5%, 4%, 3%, 2%, 1%, or 0.5% or less by weight of water and / or other liquids.

[0116] The polymer solids may comprise any of the polymers described herein, including, but not limited to, polyethylene, polypropylene, polybutene, polyisobutylene, polybutadiene, polyisoprene, poly(ethylene-co-acrylic acid), poly(lactic acid) (or polylactide), poly(glycolic acid) (or polyglycolide), poly(hydroxybutyrate), poly(butylene adipate-co-terephthalate), poly(butylene succinate), poly(hydroxybutyrate-co-hydroxyvalerate), poly(ethylene terephthalate), polyvinyl alcohol, polystyrene, poly(butyl acrylate), poly(tert-butyl acrylate-co-ethyl acrylate-co-methacrylic acid), poly(ethyl acrylate), Poly(2-ethylhexyl acrylate), poly(methyl acrylate), polyacrylonitrile, poly(acrylonitrile-co-methyl acrylate), poly(styrene-co-maleic anhydride), poly(methyl methacrylate), poly(alkyl methacrylate), polyvinylcyclohexane, poly(bisphenol A carbonate), poly(propylene carbonate), poly(1,4-butylene adipate), poly(1,4-butylene succinate), poly(1,4-butylene terephthalate), poly(ethylene succinic acid), polyvinyl acetate, poly(propylene glycol), poly(tetrahydrofuran), poly(ethyl vinyl ether), polydimethylsiloxane, nylon (aliphatic polyamide), and combinations or copolymers thereof. In a preferred embodiment, the polymer solids include natural rubber (polyisoprene), synthetic rubber (eg, polyisobutylene, polyisoprene, polybutadiene, polychloroprene, styrene-butadiene rubber, and the like).

[0117] The polymer solids may be elastomers. Exemplary elastomers include natural rubber (e.g., natural latex unvulcanized polyisoprene) and synthetic rubber. Natural rubber is primarily poly-cis-isoprene. Synthetic rubber is made from a variety of petroleum-based or fermented sugar monomers. The most common synthetic rubber is styrene-butadiene rubber (SBR), which is obtained from the copolymerization of styrene and 1,3-butadiene. Other synthetic rubbers are prepared from isoprene (2-methyl-1,3-butadiene, resulting in polyisoprene); chloroprene (2-chloro-1,3-butadiene); and isobutylene (methylpropene), which contains a small percentage of isoprene for crosslinking in forming butyl rubber.

[0118] The polymer solids may contain various additives and / or impurities in addition to one or more polymers. The additives may be one of the process additives desired for the process (e.g., a compatibilizer may be present in the polymer solids) or may be other additives such as polymerization aids used in the original process to form the polymer solids. Colorants or texturizing agents may be used as polymer-solids additives. Impurities may include, but are not limited to, soil, dust, dyes, oils, monomers, oligomers, polymer-decomposition products, metals, or combinations thereof.

[0119] The polymer solids can be virgin polymer, recycled polymer, or a combination thereof. In some embodiments, the polymer solids are natural rubber solids, which may be obtained, for example, by milling natural rubber slabs using a rubber granulator. In some embodiments, the polymer solids are synthetic rubber solids, which may be obtained by drying the product from a polymerization reactor in the form of particles.

[0120] In certain embodiments, the polymer solids are recycled rubber crumb, such as that produced from scrap tires of automobiles and trucks. During the recycling process, the steel and tire cord (fluff) may be removed, leaving behind tire rubber with a granular consistency. Continued processing through a granulator or cracker mill, optionally with the aid of cryogenic processing or mechanical means, further reduces the size of the particles. The particles may be classified based on various criteria, such as size and color.

[0121] The particle size of the polymer solids can vary widely. In various embodiments, the average particle size of the polymer solids is selected from about 10 microns to about 7500 microns, such as about 50 microns to about 5000 microns, or about 100 microns to about 2500 microns. In various embodiments, the average particle size of the polymer solids is about, at least about, or at most about 10, 25, 50, 75, 100, 150, 200, 250, 300, 400, 500, 600, 700, 800, 900, 1000, 1500, 2000, 2500, 3000, 3500, 4000, 4500, 5000, 5500, 6000, 6500, 7000, or 7500 microns, including any range therebetween.

[0122] The particle shape of the polymer solids may also vary: there may be substantially a single shape or a plurality of shapes present in the polymer solids, which may be, for example, spherical, ovoid, cubic, cylindrical, pyramidal, prismatic, high aspect ratio fibers, or random shapes.

[0123] Some variations provide a process for forming a particulate masterbatch, the process comprising: (a) providing a plurality of particulates in the form of a particulate slurry comprising water; (b) optionally introducing the particulate slurry and a first process additive into a first mixing unit, the first process additive comprising a pH adjuster; (c) optionally transferring the particulate slurry and a second process additive to a second mixing unit; (d) optionally, transferring the particulate slurry to a homogenizer; (e) optionally, transferring the particulate slurry to a centrifuge to remove a first portion of the water; (f) transferring the particulate slurry, polymer solids, and optionally a third process additive to a screw mixer configured to remove a second portion of the water, thereby producing a particulate masterbatch. wherein step (a), any of steps (b) through (e), and step (f) are performed substantially sequentially.

[0124] By "any of steps (b) through (e)" being performed substantially sequentially, it is meant that, if certain process steps are included in the process, the step is substantially in sequence with respect to the steps listed before and after it. For example, step (d) follows step (a) if included, follows step (b) if included, follows step (c) if included, follows step (e) if included, and follows step (f).

[0125] FIG. 3 is an exemplary block-flow diagram illustrating the process and system of the present invention utilizing polymer solids in some embodiments. The dashed lines and boxes indicate optional streams and units, respectively. In FIG. 3, a slurrying unit is provided to combine the particulates with water (or other solvent). After a pH adjuster (labeled "pH Agent" in FIG. 3) is added, the stream enters a first mixing unit. If a pH adjuster is not required, for example because the pH is at the desired value from the slurrying unit, the first mixing unit may be omitted. The second mixing unit is optional, but is preferred if one or more process additives are introduced upstream of the second mixing unit, as shown in FIG. 3. In this process diagram, both the homogenizer and the centrifuge are optional. The polymer solids are fed into the extruder, preferably at the feed throat.

[0126] In Figure 3, the compatibilizer is fed to the extruder, preferably at the feed throat or side port. Feeding the compatibilizer to the side port is preferred, so that there is less contact of water with the compatibilizer in the extruder, which in some embodiments avoids the degradation of hydrolytic compatibilizers. Some moisture sensitive compatibilizers are preferably added at the end of the extruder after most or all of the water has been removed to avoid degradation reactions caused by hot water. Compatibilizers and / or other process additives may be added upstream of the extruder in addition to (or instead of) addition to the extruder, followed by in-line mixing.

[0127] In some embodiments, steps (c), (d), and (e) are performed and steps (a)-(f) are performed substantially sequentially. In certain embodiments, one or two of steps (c), (d), and (e) are performed and all process steps are performed substantially sequentially.

[0128] In some embodiments, the first mixing unit is a first static in-line mixer. In these or other embodiments, the second mixing unit is a second static in-line mixer.

[0129] In some embodiments, the plurality of particulates is first introduced into a premix unit prior to step (b), for example, the plurality of particulates may be slurried with water in a premix unit, which may be referred to as a slurrying unit when a slurry is formed.

[0130] In some embodiments employing step (e), the centrifuge is a decanter centrifuge.

[0131] The second process additive can be a compatibilizer that compatibilizes the particulate with the polymer solids. Alternatively, or additionally, the third process additive can be a compatibilizer that compatibilizes the particulate with the polymer solids. The third process additive can be transferred directly to the screw mixer through an inlet port or can be added to the input stream introduced into the screw mixer. Compatibilizers are described later in this specification.

[0132] In some embodiments, step (f) utilizes heating to facilitate removal of water from the screw mixer. Optionally, preheating is performed during or prior to step (f) to preheat the particulate slurry to facilitate removal of water from the screw mixer.

[0133] In some embodiments, the screw mixer is a twin screw extruder. The twin screw extruder may be configured with multiple extruder zones that are independently temperature controlled and multiple suction vents that facilitate removal of the second portion of water. In other embodiments, the screw mixer is a twin rotor mixer.

[0134] In some embodiments, the process is continuous or semi-continuous, while in other embodiments, the process is batch or semi-batch.

[0135] The particulate masterbatch can be characterized, for example, by a dispersion index of at least 50, at least 75, or at least 90. In various embodiments, the particulate masterbatch is characterized by a dispersion index of about or at least about 50, 55, 60, 65, 70, 75, 80, 85, 90, or 95, including any range therebetween.

[0136] Preferably, processes utilizing polymer solids do not employ polymer latex coagulants.

[0137] The plurality of particulates may comprise at least two types of particulates, where at least one type of particulate is slurried prior to step (b).

[0138] In some embodiments, the plurality of particulates comprises biomass-derived particulates selected from the group consisting of cellulose, nanocellulose, hemicellulose, nanohemicellulose, lignin, nanolignin, nanolignocellulose, and combinations thereof.

[0139] In some embodiments, the plurality of particulates comprises particulates selected from the group consisting of silica, alumina, clay, nanoclay, zeolite, ceramic, metal, glass, polymer, and combinations thereof.

[0140] In some embodiments, the plurality of particulates comprises carbonaceous particulates selected from the group consisting of carbon black, graphite, graphene, activated carbon, carbon nanotubes, carbon fibers, biochar, coke, nanodiamonds, and combinations thereof.

[0141] In certain embodiments, the microparticles comprise nanocellulose. In various embodiments, the microparticles do not comprise nanocellulose.

[0142] In certain embodiments, the particulate comprises carbon black. In various embodiments, the particulate does not comprise carbon black.

[0143] In certain embodiments, the particulate comprises nanocellulose and carbon black, hi other embodiments, the particulate does not comprise either nanocellulose or carbon black.

[0144] In some variations, the present invention provides a method for producing a method of making a semiconductor device comprising: (a) providing a plurality of particulates in the form of a particulate slurry comprising water; (b) optionally introducing the particulate slurry and a first process additive into a first mixing unit, the first process additive comprising a pH adjuster; (c) optionally transferring the particulate slurry and a second process additive to a second mixing unit; (d) optionally, transferring the particulate slurry to a homogenizer; (e) optionally, transferring the particulate slurry to a centrifuge to remove a first portion of the water; (f) transferring the particulate slurry, polymer solids, and optionally a third process additive to a screw mixer configured to remove a second portion of the water, thereby producing a particulate masterbatch. wherein step (a), any of steps (b)-(e), and step (f) are carried out substantially sequentially.

[0145] In some variations, the present invention provides a system for forming a particulate masterbatch, the system comprising: (a) providing a plurality of particulates in the form of a particulate slurry comprising water; (b) optionally introducing the particulate slurry and a first process additive into a first mixing unit, the first process additive including a pH adjuster; (c) optionally transferring the particulate slurry and a second process additive to a second mixing unit; (d) optionally, transferring the particulate slurry to a homogenizer; (e) optionally, transferring the particulate slurry to a centrifuge to remove a first portion of the water; (f) transferring the particulate slurry, polymer solids, and optionally a third process additive to a screw mixer configured to remove a second portion of the water, thereby producing a particulate masterbatch. wherein step (a), any of steps (b)-(e), and step (f) are performed substantially sequentially.

[0146] In some variations, the present invention provides a system for forming a particulate masterbatch, the system comprising: (i) optionally a first mixing unit configured to mix a plurality of particulates and a pH adjuster (as a first process additive); (ii) optionally, a second mixing unit in flow communication with the first mixing unit, the second mixing unit configured to mix the plurality of particulates with a second process additive; (iii) optionally, a homogenizer in fluid communication with the second mixing unit, if present, or with the first mixing unit; (iv) optionally, a centrifuge in fluid communication with the homogenizer, if present, or with the second mixing unit, if present, or with the first mixing unit, the centrifuge configured to remove a first portion of the water; (v) a screw mixer in fluid communication with the centrifuge (or the homogenizer if the centrifuge is omitted, or the second mixing unit if the homogenizer is omitted, or the first mixing unit if the second mixing unit is omitted), the screw mixer configured to remove a second portion of the water, thereby generating a particulate masterbatch; and (vi) A discharge section for recovering the fine particle master batch. Includes.

[0147] In this specification, all references to a "matrix polymer" shall be understood as an exemplary reference to a "matrix material". Similarly, all references to a "carrier polymer" shall be understood as an exemplary reference to a "carrier material". Although many embodiments relating to polymers are described, this patent application is expressly not limited to the use of nanocellulose-dispersion concentrates in polymer systems.

[0148] The particulate masterbatch can be added to a matrix material to form a particulate composite (end use application). The matrix material can be a matrix polymer. For example, the matrix polymer can be selected from the group consisting of polyolefins, polyols, polyesters, polyamides, polylactides, polystyrenes, polycarbonates, polyacrylates, polystyrenes, styrene rubbers, natural rubbers, synthetic rubbers, polyurethanes, polyureas, poly(amide-enamines), polyanhydrides, polyhydroxyalkanoates, poly(alkene dicarboxylates), silicones, thermoplastic elastomers, thermoplastic polyurethanes (TPUs), synthetic rubbers, natural rubbers, carbonaceous polymers, and combinations or copolymers thereof.

[0149] Alternatively, or in addition, the matrix material can be a material other than a polymer, such as a material selected from the group consisting of paper, paperboard, fiber and wood composites (e.g., particle board and molded pulp products), emulsions, hydrogels, carbon, organic solids, inorganic solids, oils, organic liquids, inorganic liquids, cementitious materials (e.g., concrete or cement), minerals, ceramics, metals, metal alloys, glasses, and combinations thereof. The non-polymeric matrix material can be, for example, an adhesive matrix, a battery electrode matrix, a bio-ink matrix, an electronic ink matrix, or an asphalt matrix.

[0150] In some embodiments, the matrix material includes a polymer selected from polyesters, polyolefins, polyamides, polystyrenes, styrenic rubbers, natural rubbers, synthetic rubbers, polyurethanes, polyureas, poly(amide-enamines), polyanhydrides, polyacrylates, polyhydroxyalkanoates, poly(alkene dicarboxylates), silicones, thermoplastic elastomers, thermoplastic polyurethanes (TPUs), synthetic rubbers, natural rubbers, or combinations or copolymers thereof. Some polymer blends include polylactides, polyhydroxyalkanoates, aliphatic-aromatic copolyesters, both polylactides and aliphatic-aromatic copolyesters, polyethylene, and / or polypropylene.

[0151] In various embodiments, the polymer is polyethylene, polypropylene, polybutene, polyisobutylene, polybutadiene, polyisoprene, poly(ethylene-co-acrylic acid), poly(lactic acid) (or polylactide), poly(glycolic acid) (or polyglycolide), poly(hydroxybutyrate), poly(butylene adipate-co-terephthalate), poly(butylene succinate), poly(hydroxybutyrate-co-hydroxyvalerate), poly(ethylene terephthalate), polyvinyl alcohol, polystyrene, poly(butyl acrylate), poly(tert-butyl acrylate-co-ethyl acrylate-co-methacrylic acid), poly(ethyl acrylate), poly(2-ethylhexyl acrylate), The poly(methyl acrylate), polyacrylonitrile, poly(acrylonitrile-co-methyl acrylate), poly(styrene-co-maleic anhydride), poly(methyl methacrylate), poly(alkyl methacrylate), polyvinylcyclohexane, poly(bisphenol A carbonate), poly(propylene carbonate), poly(1,4-butylene adipate), poly(1,4-butylene succinate), poly(1,4-butylene terephthalate), poly(ethylene succinic acid), polyvinyl acetate, poly(propylene glycol), poly(tetrahydrofuran), poly(ethyl vinyl ether), polydimethylsiloxane, nylon (aliphatic polyamide), and combinations or copolymers thereof. Carbonaceous polymers may also be incorporated into the composite. Examples of carbonaceous polymers include polyacenaphthylene, graphite, graphene, carbon fiber, lignin, and asphalt.

[0152] Polymers that may be included in the microparticle composites may be, for example, hydrophobic, partially hydrophobic, or lipophilic. Hydrophilic polymers may be modified to impart at least partial hydrophobicity by suitable coatings or combinations of components (e.g., interpenetrating networks of polymers).

[0153] The polymer or copolymer may be produced by polymerizing one or more monomers selected from the group consisting of acrylics, amides, carbons, carbonates, dienes, esters, ethers, fluorocarbons, imides, olefins, organic acids (e.g., lactic acid, glycolic acid, succinic acid, hydroxypropionic acid, etc.), styrenes, siloxanes, vinyl acetals, vinyl and vinylidene chlorides, vinyl esters, vinyl ethers, vinyl ketones, vinyl pyridines, vinyl pyrrolidones, and combinations thereof.

[0154] The polymer in the particulate composite may include a thermoplastic polymer, a thermosetting polymer, or a combination thereof. Thermosetting polymers include, but are not limited to, polyurethanes, polyesters, polyureas, polyisoprenes (including natural or synthetic rubbers), phenol-formaldehyde resins, polyepoxides, polyimides, polycyanurates, polyfurans, silicones, and combinations or copolymers thereof.

[0155] In some embodiments, the matrix polymer is specifically an elastomer. Exemplary elastomers include natural rubber (e.g., natural latex unvulcanized polyisoprene) and synthetic rubber. Natural rubber is primarily poly-cis-isoprene. Synthetic rubber is made from a variety of petroleum-based or fermented sugar monomers. The most common synthetic rubber is styrene-butadiene rubber (SBR), which is obtained from the copolymerization of styrene and 1,3-butadiene. Other synthetic rubbers are prepared from isoprene (2-methyl-1,3-butadiene, resulting in polyisoprene); chloroprene (2-chloro-1,3-butadiene); and isobutylene (methylpropene), which contains a small percentage of isoprene for crosslinking in forming butyl rubber.

[0156] In some embodiments, the matrix polymer is biobased, biodegradable, and / or compostable. In these or other embodiments, the carrier polymer is biobased, biodegradable, and / or compostable. In some embodiments, the matrix polymer or carrier polymer is or includes a biodegradable polymer, such as any of the polymers described in Vroman and Tighzert, "Biodegradable Polymers", Materials 2009, 2, 307-344, incorporated herein by reference. In some embodiments, the nanocellulose-containing composite product is 13 For example, the renewable carbon content may be at least 50%, 60%, 70%, 80%, 90%, 95% or 100% renewable carbon content as measured by C analysis.

[0157] Many types of composite products are possible, including films, coatings, packaging, household products, fibers, fabrics, apparel, consumer durables, nonwovens, etc. The composite product can be in the form of, for example, pellets, extruded parts, injection molded parts, blow molded parts, spun fibers, laminated sheets, films, foams, containers, bags, engineered parts, 3D printed substrates, 3D printed parts, or combinations thereof.

[0158] Nanocellulose will now be further described. As previously mentioned, nanocellulose is one type of microparticle that may be used to form a masterbatch, although it will be understood that the present invention is applicable to other than nanocellulose.

[0159] Nanocellulose has attracted attention as a nanostructured material. It is derived from a natural resource, cellulose (the most abundant polymer on earth), and therefore has the characteristics of biodegradability and environmental sustainability. In addition, nanocellulose offers great technological potential to improve the mechanical strength and other properties of composites, independent of the social and environmental sustainability of nanocellulose. Nanocellulose is composed of parallel linear polysaccharide molecules. In addition to its abundance and sustainability, nanocellulose has attractive physicochemical properties such as very high stiffness and strength.

[0160] Nanocellulose is being developed for use in a wide variety of applications such as polymer reinforcement, antimicrobial films, biodegradable food packaging, printing papers, pigments and inks, paper and board packaging, barrier films, adhesives, biocomposites, wound healing, pharmaceuticals and drug delivery agents, textiles, water soluble polymers, building materials, recyclable internal and structural parts for the transportation industry, rheology modifiers, low calorie food additives, cosmetic thickeners, pharmaceutical tablet binders, bioactive papers, Pickering stabilizers for emulsions and particle stabilized foams, coating formulations, films for optical switching, and detergents.

[0161] However, serious technical challenges exist for the widespread use of nanocellulose. In particular, it is very difficult to remove water from nanocellulose suspensions to maintain the nanoscale dimensions. In most cases, nanocellulose particles are processed as aqueous suspensions due to their hydrophilic nature and tendency to agglomerate during drying. There is an industrial need to develop robust dispersion and drying processes that maintain the nanoscale dimensions for material applications where a dry form is required. A drier form of nanocellulose would also reduce the high transportation costs of dilute aqueous suspensions and expand the number of end-use applications where there is a limit to the amount of water that can be added to the product.

[0162] For both cellulose nanocrystals and cellulose nanofibrils (or microfibrils), the dispersibility of nanocellulose in non-aqueous polymers and other systems remains an issue, as dry forms of nanocellulose are typically required for incorporation. Nanocellulose has a tendency to irreversibly self-bond during drying, which results in large agglomerates of nanocellulose. Large agglomerates often prevent or even eliminate the intended property benefits for the polymer composite or other system in which the nanocellulose particles are introduced. For example, well-dispersed nanocellulose particles in a polymer can provide significant mechanical strength enhancement. When nanocellulose is agglomerated, however, there may be no mechanical strength enhancement at all, or even worse, the large agglomerates can become stress concentrators and cause premature failure of the polymer part.

[0163] Various drying approaches have been attempted with a view to improving the dispersibility of nanocellulose in non-aqueous products. These approaches usually require extreme measures that prove difficult to scale up to commercial quantities and are therefore uneconomical. Generally, these methods are based on lyophilization (freeze-drying) of nanocellulose, an established laboratory method to prevent irreversible interparticle bonding of nanocellulose. Freeze-drying is neither economical nor scalable for commercial production of nanocellulose.

[0164] For virtually all non-aqueous applications in which nanocellulose is used, improving its dispersibility and therefore its utility and benefits for these applications has been a major obstacle to the implementation of nanocellulose. It has therefore become important to improve nanocellulose dispersibility using economical methods to make nanocellulose highly dispersible in polymers and other systems. Economical methods usually entail dry compositions containing nanocellulose. Dry forms of nanocellulose are particularly important in the field of thermoplastic processing, such as extrusion and injection molding, where hot melt processes take place. During hot melt processes involving non-polar thermoplastics, water is an obstacle to good processing.

[0165] Dewatering or concentrating nanocellulose slurries for more efficient transport or use in applications where water use is limited is inherently difficult due to the high water retention capacity and high viscosity of these materials at low concentrations. For water-based applications, end users require nanocellulose "concentrates" with the highest possible solids content while still being rapidly redispersible with low-energy standard mixing equipment. Depending on the application, nanocellulose may require redispersion in water so that its inherent and purposefully designed nanoscale properties are preserved.

[0166] The polymer latex may function as a dispersant / desiccant for nanocellulose (or other particulates). In some variations, dewatering and drying of the aqueous nanocellulose slurry utilizes a twin-screw system (e.g., a twin-screw extruder) configured to allow for the release of water vapor. The dispersant / desiccant is added to the nanocellulose slurry, which is ultimately dewatered in the twin-screw system. Twin-screw systems with one or more system vents work surprisingly well for dewatering the nanocellulose slurry. As water is removed from the system vents, the dispersant / desiccant prevents agglomeration and irreversible self-binding of the nanocellulose.

[0167] As mentioned, it is often desirable for composite products to incorporate individual nanocellulose particles and to prevent self-binding (agglomeration) of these particles during production or use. Nanocellulose is typically available as an aqueous dispersion produced from cellulosic biomass or via bacterial synthesis. In dilute aqueous dispersions, the nanocellulose particles remain non-agglomerated or reversibly agglomerated. For most polymer systems, for example, the aqueous dispersion itself cannot be introduced into the polymer matrix, and the water must be removed first. Even for aqueous systems, additive products that contain as little water as possible are preferred to minimize product delivery costs and the amount of water introduced by the additive into the end-use product system. In general, it is not acceptable for an additive to introduce excessive amounts of water into the product system, such that the product would require dehydration or drying beyond normal levels.

[0168] The dried or dehydrated (concentrated) form of the masterbatch may be incorporated into a wide range of plastics, elastomers and adhesives, as well as non-polymeric matrices including electronic inks, sealants, and other non-aqueous applications.

[0169] A "dispersing / desiccant" as intended herein is a chemical or combination of chemicals that functions to prevent irreversible agglomeration of nanocellulose during drying or dehydration. The dispersing / desiccant disclosed herein is selected to hold nanocellulose particles apart by preventing bonding between nanocellulose particles as the aqueous dispersion is dried or dehydrated (removal of water). In the absence of an effective dispersing / desiccant, irreversible bonding between nanocellulose particles has been observed with heat drying as low as about 20 wt% solids slurry. The dispersing / desiccant also holds the nanocellulose particles apart while it is incorporated into the masterbatch product, as well as effectively and easily releasing the individual nanocellulose particles during compounding of the composite product, thereby maximizing the effectiveness of the nanocellulose. To reduce or prevent self-bonding of nanocellulose during drying or dehydration, the dispersing / desiccant may be selected to sufficiently interact with the surface of the nanocellulose and / or to distribute homogeneously between the nanocellulose particles, thereby reducing or preventing agglomeration of the nanocellulose.

[0170] In this patent application, "dewatering" refers to the removal of liquid water from the nanocellulose slurry. "Drying" refers to a relatively high degree of dewatering, up to and including the removal of all water from the nanocellulose, typically using thermal energy.

[0171] As used herein, "nanocellulose-dispersion concentrate" refers to a composition containing at least nanocellulose and a dispersing / desiccant. "Dehydrated nanocellulose", "dry nanocellulose", "dehydrated nanocellulose slurry", etc. refer to a composition containing nanocellulose and optionally a dispersing / desiccant.

[0172] Preconcentration in a centrifuge using mechanical separation is advantageous to reduce the total volume fed to the twin-screw extruder (or other screw mixer), thereby increasing the throughput on a nanocellulose basis. Mechanical separation means that separation is achieved using mechanical forces such as centrifugal or centripetal forces, or, in some cases, physical forces such as pressure caused by the permeation of water through a filtration medium or membrane. An exemplary centrifuge is a decanter centrifuge that employs high speed rotation with centrifugal force to separate nanocellulose, which has a higher density than water, from the water that is continuously removed (dencanted). An exemplary filtration device is a pressure filter that employs high pressure air (or other inert gas) to result in a mat of nanocellulose and a water-rich filtrate. Filtration devices include filter presses, belt presses, etc.

[0173] The extruder feeding subsystem can essentially consist of a conventional hopper feeding system. The hopper is well known for feeding the wet solids to the extruder. If the wet solids are not a free-flowing material, the hopper may be designed with a rotating agitator and / or wiper blades, or a hopper shaker to prevent the feed material from hanging.

[0174] As intended herein, a "two-screw system" is a machine that utilizes at least two solid screws or rotors rotating (radially) with preferably small gaps between them to impart substantial shear forces to the material being processed. In this case, where the material is a nanocellulose (or other particulate) slurry, the high shear and preferably small gaps create a thin layer of material with a large surface area exposed for evaporation of water. The high shear forces can mix the nanocellulose slurry with the polymer latex. Also, in some cases, as the water is released, the mixing provided by the two screws or rotors causes the particles to tumble and grind so that their drying is relatively uniform.

[0175] The twin-screw system can be a continuous system, a semi-continuous system, a semi-batch system, or a batch system. If the twin-screw system is a continuous or semi-continuous twin-screw extruder, the material is continuously conveyed axially through the system from the feed subsystem to the extruder outlet over a period of time. If the twin-screw system is a batch or semi-batch twin-screw mixer, the material is first added to the system, then the system is typically closed except for venting or removing water vapor, and then subjected to mixing via high shear forces caused by two rotors rotating radially, preferably with a small gap between the rotors. After a period of time (batch time), the system is opened and the processed material is collected. In a semi-batch system, the system can be operated for a period of time, and then material can be periodically added to or removed from the system (e.g., the release of water can be intermittent, or dehydrated nanocellulose can be periodically collected from a valve). In the case of batch or semi-batch, the feed subsystem may be the vessel itself which may be initially loaded, and the system outlet may also be the vessel itself after the batch operation.

[0176] In the case where the twin screw system is a twin screw extruder, the solid screws are typically constructed of metal or metal alloys such as stainless steel, optionally with a ceramic coating such as chromium carbide. The screws may be manufactured as a single piece or may be segmented and assembled onto a shaft. The screws may be arranged parallel to one another or in a conical arrangement where the screw axes are not parallel to one another but converge along the length of the extruder.

[0177] A twin screw extruder can be a co-rotating twin screw extruder, a counter-rotating twin screw extruder, or other type of twin screw extruder (e.g., a gear pump extruder). A twin screw is a co-rotating screw if the two screws are designed to rotate in the same radial direction (co-rotating). A twin screw is a counter-rotating screw if the two screws are designed to rotate in opposite radial directions. The screw flights can be designed so that the two screws intermesh with each other (intermeshing screws) or do not fully intermesh with each other (non-intermeshing screws). The screws are contained within one or more barrels that form an outer wall around the screws, thereby containing the material during processing.

[0178] For continuous systems, counter-rotating twin-screw extruders have beneficial material feeding and conveying characteristics. Residence time and material temperature control in counter-rotating twin-screw extruders are also relatively uniform. However, air entrapment, high pressure build-up, and low maximum screw speeds can be disadvantages. The advantage of co-rotating twin-screw extruders is that the screws wipe each other cleanly (self-wiping) with good mixing, and high screw speeds and high output can be achieved. Co-rotating twin-screw extruders can also be desirable due to low screw and barrel wear.

[0179] For continuous systems, the screw may be designed to incorporate different screw elements along the screw length. Such screw elements may include, but are not limited to, flighted elements, mixing elements, and zoning elements. Flighted elements propel the material forward beyond the barrel port, through the mixer, and out of the extruder through the die. Mixing elements promote mixing of the various components being processed. Zoning elements separate two operations. Some elements may be multi-functional.

[0180] For continuous systems, the mixing efficiency of a twin screw extruder can be increased by incorporating many mixing elements along the screw. These and other elements can be slotted into a central shaft to make up the screw section. Preferably, the length, number and configuration of the elements can be easily varied. The elements can be in various forms such as inverted screw flights, kneading disks, pins, rotors, slotted vanes, blister rings, etc. The mixing elements can be designed to impart extensional mixing and planar shear to the material being processed to promote dispersive mixing. The mixing elements can be designed to provide flow division and recombination to promote distributive mixing.

[0181] For continuous systems, the outer screw diameter, inner screw diameter and channel depth are important twin screw extruder design parameters because these parameters determine the available free volume and torque (and therefore radial shear). As the channel depth increases, the inner screw diameter decreases and the achievable shaft torque decreases.

[0182] Generally, the screw design will be tailored to the particular application (e.g., type of particulate, choice of polymer latex, degree of dewatering desired, throughput, etc.) One skilled in the art of twin-screw extrusion will be able to customize the screw design using known principles and calculations.

[0183] This specification incorporates by reference Goff et al., The Dynisco Extrusion Processors Handbook, 2nd edition, 2000, for teachings on twin screw extruder principles and design parameters. This specification also incorporates by reference Martin, "Twin Screw Extruders as Continuous Mixers for Thermal Processing: a Technical and Historical Perspective", AAPS PharmSciTech, Vol. 17, No. 1, February 2016, for teachings on various twin screw extruder designs and operating principles.

[0184] Extruders employing three or more screws are within the scope of twin screw extruders herein. In a triple screw extruder, all three screws may be co-rotating, or two screws may be co-rotating with one screw counter-rotating radially relative to the other screw.

[0185] A gear pump extruder is essentially a simple twin screw extruder that moves material with the action of two intermeshing gears, which are relatively short length screws or rotors. The gears are typically constructed of metal or metal alloys such as stainless steel, optionally with a ceramic coating such as chromium carbide. If the two gears are designed to rotate in the same radial direction (co-rotation), the gear pump extruder is a co-rotating gear pump extruder. If the two gears are designed to rotate in opposite radial directions, the gear pump extruder is a counter-rotating gear pump extruder. The gear flights may be designed so that the two gears intermesh with each other or do not fully intermesh with each other.

[0186] In some embodiments, the screw mixer is a gear pump extruder operated in a batch mode rather than a continuous mode. The intermeshing gears can be designed to be co-rotating or counter-rotating, and the gear flights can be designed so that the two gears intermesh with each other or do not completely intermesh with each other. The gear pump extruder is first loaded with the nanocellulose slurry and, optionally, the dispersion-desiccant. The batch gear pump is operated for a certain time (batch time) to achieve intimate high shear mixing and release of water vapor from the vent.

[0187] In some embodiments, the screw mixer is a batch or semi-batch twin-shaft rotor mixer. A twin-shaft rotor mixer is configured with two rotors that can be intermeshing or non-intermeshing. The two rotors rotate (radially) to impart significant shear forces to the material being processed. The high shear forces allow the nanocellulose (or other particulate) slurry to be mixed with the dispersing / desiccant. The rotors are typically constructed of metal or metal alloys such as stainless steel, optionally with a ceramic coating such as chromium carbide. The two rotors may be designed to rotate in the same radial direction (co-rotating) or in opposite radial directions (counter-rotating). In principle, such twin-shaft rotor mixers can be scaled to commercial scale.

[0188] A twin-shaft rotor mixer comprises a cavity (or mixing chamber) with vaned rotors, where the vanes pump and intimately mix the materials in opposite directions. The rotors of a twin-shaft rotor mixer may be designed with a number, shape and angle of vanes optimized for a particular application. The rotors typically have two or four flights, although other numbers of flights are possible. The rotors of a twin-shaft rotor mixer may be selected from, for example, tangential rotors, roller rotors, delta rotors, cam rotors, sigma rotors, Banbury rotors, or other industrially available rotors. In some embodiments of a twin-shaft rotor mixer, the two rotors rotate towards each other at slightly different speeds. Each rotor has blades that extend along the length of the rotor in a generally helical configuration. Each rotor may be hollow to allow for cooling or heating by the flow of water or a suitable heating agent. An example of a commercial-scale twin-blade rotor is the well-known Banbury design.

[0189] For batch or semi-batch systems, the mixing efficiency of a twin-shaft rotor mixer can be increased by incorporating many mixing elements into the rotor. The rotor elements can be of various configurations. The rotor mixing elements may be designed to impart extensional mixing and planar shear to the material being processed to promote dispersive mixing. The rotor mixing elements may be designed to provide flow division and recombination to promote distributive mixing. Generally, the rotor design will be tailored to the specific application (e.g., type of particulate, choice of polymer latex, desired degree of dewatering, throughput, etc.). Those skilled in the art of twin-shaft rotor mixers will be able to customize the rotor design using known principles and calculations.

[0190] The twin-screw system may be designed to operate at an average system temperature of, for example, about 120°C to about 300°C. The twin-screw system is preferably designed to operate at a maximum system temperature that is lower than the thermal decomposition onset temperature of the particulates being dehydrated or dried, and preferably lower than the thermal decomposition onset temperature of the polymer latex. In some embodiments, when the twin-screw system is a twin-screw extruder, multiple extruder zones are provided, where the zone temperatures associated with each of the extruder zones can be independently controlled, such as through a control panel or computer interface. When the twin-screw system is a batch or semi-batch twin-screw rotor mixer, the mixer can be operated at a single temperature or, if desired, at a temperature that is changed over time.

[0191] The twin screw system may be heated with a heat transfer medium selected from the group consisting of steam, hot oil, electrical heating elements, and combinations thereof. The twin screw system may be cooled with a heat transfer medium selected from the group consisting of cooling water, air, oil, and combinations thereof. In the case of a twin screw extruder, the heating and cooling configuration may be designed based on the desired temperature profile along the length of the screw extruder, the throughput, the material present, the shear rate, the screw design, and other parameters.

[0192] In some embodiments, twin screw systems are electrically heated using a resistance coil, band or cuff wrapped or bolted around the barrel or mixer bowl. Electrical current is passed through a resistance wire inside the coil in response to demand such as initiated by a thermocouple. The resistance creates heat, which increases the barrel or mixer bowl temperature and the system internal temperature through heat transfer. For twin screw extruders, the resistance setting required to achieve the desired temperature will depend on the screw rotation speed, pressure in the system and throughput.

[0193] In some embodiments, the twin-screw extruder is configured with steam heating for one or more barrels. Upon demand, such as initiated by a thermocouple, steam is introduced to the barrel surface for indirect heating (i.e., steam is not introduced directly into the extruder), thereby increasing the barrel temperature and the extruder internal temperature via heat transfer. For twin-screw extruders, the steam pressure and flow rate to achieve the desired temperature will depend on the screw rotation speed, pressure in the system, and throughput.

[0194] In some embodiments, the twin screw extruder is equipped with an air cooling system to reduce the temperature if excessive heating occurs (e.g., if electrical heating exceeds a set point or if shear heating becomes excessive.) An exemplary air cooling system consists of a fan that circulates air around the barrel on demand.

[0195] In some embodiments, the twin-screw extruder is equipped with a liquid cooling system, such as a closed loop heat exchanger that uses cooling water contained in a sealed coil around the barrel, whereby steam from this cooling water is cooled by the water flow when the set point temperature is exceeded, causing the cooling water vapor to condense and absorb additional heat.

[0196] The twin-screw system is preferably configured with one or more system vents to remove at least a portion of the water from the nanocellulose slurry. A "vent" is a port, adjustable valve, pressure relief valve, pressure relief disk, water-permeable membrane, or other device that allows the release of water vapor from the system. The vents may be normally open or normally closed, e.g., the vents may be designed to open only when there is sufficient outward vapor pressure or on demand. In the case of a twin-screw extruder, the vents may be referred to as extruder vents. In the case of a twin-screw rotor mixer, the vents may be referred to as mixer vents.

[0197] In some embodiments of twin screw extruders, the extruder vent is integrated into the barrel. In these or other embodiments, the extruder vent may be configured in a vent ring or other vent element between axially adjacent barrels. In the case of gear pump extruders, the extruder vent may be integrated into the gear box, case seal, or suction port, for example.

[0198] Generally, system vents allow removal of volatiles such as water vapor and trapped air from the system. Dewatering or drying a nanocellulose (or other particulate) slurry means that at least the water (or other predominantly liquid) is removed. Other components may be removed from the system vents, sometimes unintentionally (e.g., slight entrainment of solids). In some embodiments, the system vents allow removal of some water as well as components derived from the nanocellulose production process, such as acids, sugar decomposition compounds, or lignin-derived compounds.

[0199] The number of system vents can vary, such as 1, 2, 3, 4, 5 or more, depending on, for example, the total length of the twin screw extruder or the total volume of the twin rotor mixer. The location of the extruder vents can vary along the length of the twin screw extruder. For example, if there is an increasing temperature profile along the extruder length, the extruder vents can be located near the end of the extruder where water evaporation is faster or more thermodynamically favorable.

[0200] The system vents may, for example, allow vapors to be vented to the atmosphere, or may be fitted to flow lines so that the vapors can be captured and possibly reused for other purposes or analyzed for composition. The flow lines may be in communication with a vacuum system so that the vents are under vacuum. If multiple vents are utilized, each vent may be the same or different sizes, i.e., one vent may have a larger opening area (for the release of more vapor) than the other vents.

[0201] In some embodiments, at least one of the system vents is operated under reduced pressure. When multiple system vents are utilized, each of the system vents may be operated under reduced pressure, or less than the total number of system vents may be operated under reduced pressure. The vacuum pressure may be from about 0.01 bar to about 0.99 bar (absolute), such as about 0.05, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 0.95 bar. When multiple system vents are provided, they may be operated at the same pressure or different pressures. As shown, when three system vents are provided (as suggested in Figures 1 and 2), all three vents may be connected to a common reduced pressure system operated at a gauge pressure of -0.9 bar, which is 0.1 bar absolute. Alternatively, for example, two system vents may be at a pressure of 0.5 bar, while one vent may be at atmospheric pressure (1 bar).

[0202] The twin screw extruder outlet is typically configured with an extruder die. The extruder die is an assembly located at the end of the extruder and with an orifice that allows the dehydrated nanocellulose to exit. The extruder die is a block of metal or metal alloy that can be the same material as the screw and / or barrel. In certain embodiments, an extruder vent is configured as part of the extruder die at or near the extruder outlet. If the extruder outlet is open to the atmosphere, an additional amount of water vapor can be released.

[0203] In addition to the number and size of the extruder vents and the vacuum level, other parameters may determine the efficiency of water removal from a twin-screw extruder. For example, a longer residence time, especially in the extruder vented zone, may help to allow more time for mass transport of water to the vent. The screw design may be optimized so that one or more screw elements promote the flashing and removal of water from the extruder vent. A larger surface area of ​​the mixture due to high shear rates may help by reducing the limitations of diffusion and / or convective mass transport. Of course, the temperature and pressure in the extruder or extruder zones will determine whether water exists in liquid or vapor state at thermodynamic equilibrium. True equilibrium may or may not exist.

[0204] Those skilled in the chemical industry can experiment with a twin-shaft system to determine the number of vents required to achieve a desired degree of dewatering or drying by varying the number and size of vents, vacuum pressure, screw or rotor design, and process conditions in the system. Alternatively, or additionally, those skilled in the chemical industry can simulate a twin-shaft system to calculate or estimate the number of vents required to achieve a desired degree of dewatering or drying by varying the number of vents, vacuum pressure, and process conditions. For example, it may be assumed that each vent can be modeled as one equilibrium flash stage with complete separation of vapors and no entrainment of solids. In reality, due to the large surface area (thin film) in a twin-shaft system, more than one equilibrium flash may occur at each vent.

[0205] If an optional kneading device is present, the kneading device may be directly connected to the system outlet (e.g., extruder outlet) such that the system outlet is essentially the kneading device inlet. Alternatively, the masterbatch may be collected at the outlet and then optionally introduced into the kneading device at a later time and / or at a different location. The kneading device may be selected from, for example, a hammer mill, a ball mill, a jet mill, an impact crusher, a crusher, a cage mill, a grinder, or an extruder. The kneading device may be operated to reduce the particle size of the nanocellulose-dispersed concentrate to, for example, an average diameter range of about 10 microns to about 1 millimeter, such as about 25, 50, 100, 200, 300, 400, 500, 600, 700, 800, 900, or 950 microns.

[0206] In various embodiments, the dispersing / desiccant is in the form of a polymer latex selected from the group consisting of natural rubber latex, wax, polyolefin, olefin-maleic anhydride copolymer, olefin-acrylic acid copolymer, polyol, fatty acid, fatty alcohol, polyol-glyceride ester, polydimethylsiloxane, polydimethylsiloxane-alkyl ester, polyacrylamide, starch, cellulose derivatives, and combinations or reaction products thereof.

[0207] The twin screw system can be a twin screw extruder, such as a co-rotating twin screw extruder, a counter-rotating twin screw extruder, or other type of twin screw extruder (e.g., a gear pump extruder). Several designs and operating principles of twin screw extruders have been discussed above.

[0208] The twin screw system temperature is preferably monitored and controlled. System temperature refers to the temperature of the material within the system, not the outside barrel or mixer bowl temperature, although the barrel or mixer bowl temperature may be measured and related to the system temperature. If the twin screw extruder has multiple extruder zones, the zone temperatures associated with each of the extruder zones are preferably monitored and controlled independently. Temperature control may utilize programmable control logic implemented by a computer using well known techniques.

[0209] A twin screw system may be operated at an average system temperature of, for example, about 120°C to about 250°C. The average system temperature may be calculated as the average of all the measured temperatures or may be estimated based on the temperature measurements and other parameters (e.g., amount of water discharged, solids concentration at the outlet, etc.). In a continuous twin screw extruder, zone temperatures, i.e., temperatures at different spatial points, may be measured. In a batch or semi-batch twin screw rotor mixer, temperatures at different times may be measured and the system may be at a constant temperature or at a temperature that varies with time. In the case of a twin screw extruder, even in a given extruder zone, the local temperature profile around and between the screws is usually complex, so the measured temperature represents the average for that zone. In various embodiments, the average extruder temperature is about, at least about, or at most about 120°C, 125°C, 130°C, 135°C, 140°C, 145°C, 150°C, 160°C, 170°C, 180°C, 190°C, 200°C, 210°C, 220°C, 230°C, 240°C, or 250°C.

[0210] The twin-screw system may be operated at a maximum extruder temperature of, for example, about 150° C. to about 300° C. In various embodiments, the maximum system temperature is about, or up to about 150° C., 160° C., 170° C., 180° C., 190° C., 200° C., 210° C., 220° C., 230° C., 240° C., 250° C., 260° C., 270° C., 280° C., 290° C., or 300° C. It is preferred that the twin-screw system be operated at a maximum system temperature that is below the onset temperature of thermal decomposition of the nanocellulose (or other selected particulate).

[0211] In certain continuous embodiments, the zone temperatures increase along the length of the twin screw extruder. In certain other embodiments, the zone temperatures decrease along the length of the twin screw extruder. It is also possible to have a non-monotonic temperature profile along the extruder.

[0212] The twin-shaft system may be heated with a heat transfer medium selected from the group consisting of steam, hot oil, electric heating elements, and combinations thereof. The twin-shaft system may be cooled with a heat transfer medium selected from the group consisting of cooling water, air, oil, and combinations thereof. The heating and cooling configuration may be designed based on the desired temperature profile, throughput, materials present, shear rate, screw or rotor design, and other parameters.

[0213] A continuous twin screw extruder can be operated over a wide range of shear rates, including axial and radial shear rates. Without limiting the scope of the invention in any manner, the twin screw extruder can be operated over a range of shear rates of about, or at least about, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, 120, 130, 140, 150, 160, 170, 180, or 190 s. -1 For example, about 10 s -1 ~about 200s -1 Without limiting the scope of the invention in any manner, the twin screw extruder may be operated at an average axial shear rate of about, or at least about, 110, 125, 150, 200, 300, 400, 500, 1000, 2000, 3000, 4000, or 5000 s-1 For example, about 100s -1 ~about 10000s -1 (10 3 The radial shear rate may be operated at an average radial shear rate of 100 / s. Typically, the radial shear rate is significantly higher than the axial shear rate. It should be noted that the local shear rate, especially for radial shear, can be substantially higher than the average shear rate.

[0214] A batch or semi-batch twin-shaft rotor mixer can be operated over a wide range of shear rates. Without limiting the scope of the invention in any manner, a twin-shaft rotor mixer can be operated over a wide range of shear rates, including at least about 25, 50, 100, 125, 150, 200, 300, 400, 500, 1000, 2000, 3000, 4000, or 5000 s -1 For example, about 10 s -1 ~about 10000s -1 The flow rate may be operated at an average radial shear rate of

[0215] The twin-screw system may be operated with an average nanocellulose residence time of, for example, about 30 seconds to about 120 minutes. In various embodiments, the average nanocellulose residence time is about, at least about, or at most about 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 15, 20, 30, 40, 50, 60, 70, 80, 90, or 100 minutes. If the twin-screw system is a batch system, the residence time is the batch time (e.g., 90 minutes).

[0216] The residence time of the water will generally vary because multiphase systems have separate residence time distributions for the different phases and because at least a portion of the water exits the twin-screw extruder, in various embodiments, the average water residence time is about, at least about, or at most about 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 minutes.

[0217] The residence time distribution of material in a twin screw extruder will depend on whether the extruder is full or starved fed. A full extruder means that all of the internal volume is filled with material except for trapped air during operation. In a starved fed extruder, there are internal extruder regions that do not contain material (nanocellulose or water) during operation. The more filled the screw gap is, the narrower the nanocellulose residence time distribution; conversely, the more starved the screw is, the wider the nanocellulose residence time distribution is. A starved screw may result in a flow pattern that is better mixed axially compared to a full piston flow. Axial mixing may be desirable for water removal since local residence times and mass transport of water in axial mixing zones with extruder vents may be higher.

[0218] In some embodiments, at least one of the system vents is operated under reduced pressure. When step (d) utilizes multiple system vents, each of the system vents may be operated under reduced pressure, or less than all of the system vents may be operated under reduced pressure.

[0219] In various embodiments, the extent of water removal from the particulate slurry exiting the twin screw system, calculated as the water removed from the particulate slurry divided by the total amount of water present in the material fed to the extruder, can vary from about 10% to 100%. The extent of water removal can be about, or at least about, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95% or 99%, including all ranges therebetween.

[0220] In various embodiments, the extent of water removal, including from the particulate slurry, from the entire system (all process steps), calculated as the water removed from the particulate slurry divided by the total amount of water present in the materials fed to the system, can vary from about 25% to 100%. The extent of water removal can be about, or at least about, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%, 99%, or 100%, including all ranges therebetween. In these embodiments, the water removed from the centrifuge can be, for example, about 10% to about 95% of the total amount of water removed from the system.

[0221] When at least one type of particulate is nanocellulose, the nanocellulose may comprise cellulose nanocrystals, cellulose nanofibrils, microfibrillated cellulose, or a combination thereof. In some embodiments, the nanocellulose comprises lignin-containing nanocellulose. In certain embodiments, the nanocellulose comprises lignin-coated nanocellulose.

[0222] As a rule of thumb, but not limited to, nanocellulose slurries can be dehydrated to approximately 10-25 wt.% nanocellulose before irreversible agglomeration begins to become significant, depending on the drying temperature profile. Notwithstanding this rule of thumb, the use of twin-screw extruders (even without the use of any dispersing / desiccant) offers benefits resulting from the particularly intimate blending that occurs in twin-screw extruders. For example, when a twin-screw system is used for dewatering or drying, the degree of agglomeration of nanocellulose or the reversibility of agglomeration can be improved, regardless of the dispersing / desiccant (if any), compared to other devices. However, it is preferable to employ a dispersing / desiccant, especially when the slurry is to be robustly dewatered (e.g., completely dried).

[0223] In some embodiments, a compatibilizer is introduced into the process of forming the particulate masterbatch. A compatibilizer is a material that promotes interaction between two other components of a mixture, thereby providing a stable phase morphology and suppressing phase separation between these two other components. For example, polymer blends typically have coarse and unstable phase morphology, which results in poor mechanical properties. Compatibilization creates a more stable and better blended phase morphology by forming interactions between two previously immiscible components. In the present invention, the two components that can be compatibilized can be particulates on the one hand and polymer latex or polymer solids on the other hand. Alternatively, or additionally, the two components that can be compatibilized can be particulates on the one hand and matrix polymer on the other hand. The compatibilizer that functions to compatibilize particulates with polymer latex or polymer solids can also function to compatibilize particulates with matrix polymer after the particulate masterbatch is introduced into the matrix polymer. In these situations, the compatibilizer may additionally function to compatibilize the polymer latex or polymer solids with the matrix polymer.

[0224] The mechanism of the compatibilizer can be varied. In some embodiments, the compatibilizer reduces the interfacial tension, thereby promoting the separation of droplets during processing. In some embodiments, the compatibilizer prevents subsequent coalescence of the droplets, thereby aiding in stabilizing the blend. The compatibilizer can function as a purely physical compatibilizer, or as a chemically reactive compatibilizer, or a combination thereof. When the compatibilizer is a chemically reactive compatibilizer, a chemical bond can be formed between the compatibilizer and at least one component to be compatibilized. In some embodiments, the chemically reactive compatibilizer functions by acting as a chemical coupling agent, forming chemical bonds between both the compatibilizer and the component to be compatibilized. The type of bond can be hydrogen bonding, ionic bonding, covalent bonding, or a combination thereof. The functional groups in the compatibilizer can react with end groups or surface groups present on the particulates and / or polymer latex or solids. Another approach is to add functional groups to the compatibilizer by grafting, such as with maleic anhydride.

[0225] The compatibilizer is selected from the group consisting of waxes, polyolefins, olefin-maleic anhydride copolymers, olefin-acrylic acid copolymers, polyols, fatty acids, fatty alcohols, polyol-glyceride esters, polydimethylsiloxanes, polydimethylsiloxane-alkyl esters, polyacrylamides, starches, cellulose derivatives, microparticles, succinic anhydrides, alkenylsuccinic anhydrides, alkylketene dimers, olefin-styrene copolymers, olefin-glycidyl copolymers, olefin-methacrylate copolymers, olefin-styrene-glycidyl copolymers, olefin-glycidyl-methacrylate copolymers, olefin-styrene-glycidyl-methacrylate copolymers, olefin-styrene-glycidyl-methacrylate copolymers, and combinations or reaction products thereof.

[0226] In some embodiments, the compatibilizer is selected from maleic anhydride-grafted natural rubber, maleic anhydride-grafted polyisoprene, maleic anhydride-grafted polybutadiene, or analogs, or combinations thereof.

[0227] In some embodiments, the compatibilizer has the formula: [ka] (In the formula, R 1 H, C1~C 24 Linear or branched alkanes, C2-C 24 Linear or branched alkenes, C6-C 24 selected from linear or branched chain aromatic compounds, or combinations thereof; and In the formula, R 2 H, C1~C 24 Linear or branched alkanes, C2-C 24 Linear or branched alkenes, C6-C 24 linear or branched chain aromatic compounds, or combinations thereof) The alkyl group is selected from alkenyl succinic anhydrides such as those having the formula:

[0228] In some embodiments using alkenyl succinic anhydrides, R 1 is C2~C 24 Linear or branched alkanes, C4-C 24 Linear or branched alkenes, C8-C 24 linear or branched chain aromatic compounds, or combinations thereof; and R 2 is C2~C 24 Linear or branched alkanes, C4-C 24 Linear or branched alkenes, C8-C 24 In certain embodiments, R is selected from linear or branched aromatic compounds, or combinations thereof. 1 is C5~C 15 and R is selected from linear or branched alkanes; 2 is C5~C 15 It is selected from linear or branched alkanes.

[0229] Succinic anhydride can be prepared, for example, by catalytic hydrogenation of the C=C double bond in maleic anhydride. Succinic anhydride can also be prepared by dehydrating succinic acid, which itself can be produced via fermentation of biomass-derived sugars using a suitable microorganism.

[0230] Alkenyl succinic anhydrides can be prepared by reacting maleic anhydride with an olefin of the desired chain length, where the C=C double bond becomes a C-C single bond, but since at least one C=C double bond is present in the olefin reactant, this double bond remains and is present in the alkenyl succinic anhydride.

[0231] In some embodiments, the compatibilizer has the formula: [ka] (In the formula, R 1 is C4~C 24 Linear or branched alkanes, C4-C 24 Linear or branched alkenes, C6-C 24 selected from linear or branched chain aromatic compounds, or combinations thereof; and In the formula, R 2 is C4~C 24 Linear or branched alkanes, C4-C 24 Linear or branched alkenes, C6-C 24 linear or branched chain aromatic compounds, or combinations thereof) The alkyl ketene dimer is selected from alkyl ketene dimers such as those having the formula:

[0232] Alkylketene dimers are a family of organic compounds based on the four-membered ring system of oxetan-2-one. In some embodiments using alkylketene dimers, R 1 is C8~C 24 Linear or branched alkanes, C8-C 24 Linear or branched alkenes, C8-C 24linear or branched chain aromatic compounds, or combinations thereof; and R 2 is C8~C 24 Linear or branched alkanes, C8-C 24 Linear or branched alkenes, C8-C 24 In certain embodiments, R is selected from linear or branched aromatic compounds, or combinations thereof. 1 is C 10 ~C 18 and R is selected from linear or branched alkanes; 2 is C 10 ~C 18 It is selected from linear or branched alkanes.

[0233] Alkyl ketene dimers can be prepared by reacting a long-chain carboxylic acid chloride with triethylamine as the tertiary amine under anhydrous conditions in an inert solvent (such as diethyl ether). After filtration of the insoluble triethylamine hydrochloride and evaporation of the solvent, the long-chain alkyl chain dimer is obtained.

[0234] In some embodiments, the compatibilizer is selected from an olefin-styrene-glycidyl-methacrylate copolymer. An exemplary olefin-styrene-glycidyl-methacrylate copolymer is a polypropylene homopolymer grafted with poly(styrene-co-methyl methacrylate-co-glycidyl methacrylate), such as AddiCo® 5933 from AddiCo of Mexico.

[0235] Some variations are: (a) about 0.05% by weight to about 50% by weight of one or more microparticles; (b) from about 0.05% to about 10% by weight of a compatibilizer selected from the group consisting of waxes, polyolefins, olefin-maleic anhydride copolymers, olefin-acrylic acid copolymers, polyols, fatty acids, fatty alcohols, polyol-glyceride esters, polydimethylsiloxanes, polydimethylsiloxane-alkyl esters, polyacrylamides, starches, cellulose derivatives, particulates, succinic anhydrides, alkenylsuccinic anhydrides, alkylketene dimers, olefin-styrene copolymers, olefin-glycidyl copolymers, olefin-methacrylate copolymers, olefin-styrene-glycidyl copolymers, olefin-glycidyl-methacrylate copolymers, olefin-styrene-glycidyl-methacrylate copolymers, and combinations or reaction products thereof; and (c) about 50% by weight to about 99.9% by weight of a matrix material The present invention provides a product comprising:

[0236] In some embodiments, the product consists essentially of the particulates, the compatibilizer, and the matrix material.

[0237] In some embodiments, the microparticles are present in the product at a concentration of about 0.1% to about 40% by weight. In various embodiments, the microparticles are present in the product at a concentration of about, at least about, or at most about 0.1, 0.2, 0.3, 0.4, 0.5, 1, 1.5, 2, 2.5, 3, 4, 5, 10, 15, 20, 25, 30, 35, or 40% by weight (including any range therebetween).

[0238] In some embodiments, the weight ratio of particulate to compatibilizer is selected from about 0.1 to about 100. In various embodiments, the weight ratio of particulate to compatibilizer is about, at least about, or at most about 0.1, 0.2, 0.5, 1, 2, 3, 4, 5, 10, 15, 20, 25, 30, 40, 50, 60, 70, 80, 90, or 100, including any range therebetween.

[0239] In some embodiments, the compatibilizer is a functionalized polyalkylene wax that is functionalized for compatibility with nanocellulose. As used herein, a "functionalized" hydrogen-containing compound is one in which at least one hydrogen atom has been replaced with a functional group. Without limitation, -H can be replaced with -OH, -COOH, =O, or other oxygen-containing functional groups. In certain embodiments, -H can be replaced with a non-oxygen-containing functional group, such as, for example, a metal, halogen, nitrogen, sulfur, or a group containing these moieties.

[0240] The functionalized polyalkylene wax can be a functionalized polyethylene wax, a functionalized polypropylene wax, a functionalized polybutylene wax, or a combination thereof. In certain embodiments, the compatibilizer is a low molecular weight oligomer or polymer of ethylene or functionalized ethylene. When functionalized ethylene is utilized, each of the repeating units may have an average of about 0.1 to about 4.0 hydrogen atoms replaced with other functional groups. The number average degree of polymerization of the ethylene or functionalized ethylene can be from 2 to 1000, such as from 5 to 500. In various embodiments, the number average degree of polymerization of the ethylene or functionalized ethylene is at least or at most 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 25, 50, 75, 100, 150, 200, 300, 400, 500, 600, 700, 800, 900, or 1000, including all ranges therebetween.

[0241] In some embodiments, the compatibilizer is a copolymer of (a) one or more C2-C4 olefins and (b) maleic anhydride. The C2 olefin is ethylene, the C3 olefin is propylene, and the C4 olefin is 1-butene, 2-butene, isobutene, 1,3-butadiene, or a combination thereof. The C2-C4 olefin can be a functionalized olefin, such as a functionalized ethylene. Maleic anhydride is an organic compound having the formula C2H2(CO)2O and is the anhydride of maleic acid. For purposes herein, polymers of maleic acid or salts thereof are also considered to be polymers of maleic anhydride. Maleic anhydride can be produced from 5-hydroxymethylfurfural, which itself can be derived, for example, from biomass (glucose dehydration). C2-C4 olefins can also be produced from biomass, such as through the dehydration of alcohol produced by fermentation of sugars.

[0242] The copolymer of C2-C4 olefin and maleic anhydride can be a block copolymer, an alternating copolymer, a random copolymer, or a combination thereof. In the case where the olefin is ethylene, for example, the copolymer can be poly(ethylene-alt-maleic anhydride) and / or poly(ethylene-graft-maleic anhydride). Graft copolymer is a type of copolymer in which one or more blocks of homopolymer are grafted onto the main chain as branches, which means that it is a branched copolymer having one or more side chains of homopolymer attached to the backbone of the main chain. Thus, poly(ethylene-graft-maleic anhydride) can also be considered as a polymer of functionalized ethylene, where ethylene is functionalized with maleic acid or maleic anhydride. This type of copolymer can also be referred to as maleated polyethylene.

[0243] In some embodiments, the compatibilizer is a copolymer of (a) one or more C2-C4 olefins and (b) acrylic acid. The C2 olefin is ethylene, the C3 olefin is propylene, and the C4 olefin is 1-butene, 2-butene, isobutene, 1,3-butadiene, or combinations thereof. The C2-C4 olefin can be a functionalized olefin, such as functionalized ethylene. Acrylic acid is an organic compound having the formula CH2=CHCOOH. For purposes herein, a polymer of acrylic acid or a salt thereof is also considered to be a polymer of acrylic anhydride.

[0244] The copolymer of C2-C4 olefin and acrylic acid can be a block copolymer, an alternating copolymer, a random copolymer, or a combination thereof. Typically, the acrylic acid is polymerized across its double bond, similar to ethylene polymerization (e.g., in a free radical copolymerization), resulting in a copolymer that can be considered a graft copolymer or a polymer of functionalized ethylene, where ethylene is functionalized with acrylic acid.

[0245] In some embodiments, the compatibilizer comprises a fatty acid. A fatty acid is a carboxylic acid having a long aliphatic chain that is saturated or unsaturated and is considered a polymer in this specification. Most naturally occurring fatty acids have an unbranched chain of 4 to 28 even carbon atoms. As used herein, the fatty acid may be selected from, for example, caprylic acid, capric acid, lauric acid, stearic acid, arachidic acid, behenic acid, lignoceric acid, cerotic acid, or combinations thereof. Fatty acids that are unsaturated and / or branched may be employed.

[0246] In some embodiments, the compatibilizer comprises a fatty alcohol. Fatty alcohols are long chain alcohols that are straight chain primary alcohols ranging from 4 to 26 carbon atoms and are considered polymeric in this specification. Exemplary fatty alcohols include lauryl alcohol (dodecanol), stearyl alcohol, and oleyl alcohol. Fatty alcohols can be oily liquids (for small carbon numbers) or waxy solids. Fatty alcohols typically have an even number of carbon atoms and a single alcohol group attached to a terminal carbon. Some are unsaturated and some are branched. Fatty alcohols that are unsaturated and / or branched can be employed. Fatty alcohols with an odd number of carbon atoms can be employed. Ethylene can be oligomerized and the oligomers subjected to hydroformylation to produce odd numbered aldehydes, which can then be hydrogenated. For example, 1-decene can be hydroformylated to C 2 aldehydes. 11 Alcohol is obtained.

[0247] In some embodiments, the compatibilizer comprises a polysiloxane. The polysiloxane may be a methyl, C2-C 24 The polysiloxane may have one or more functional groups selected from the group consisting of alkyl, epoxide, hydroxy, amino, carboxyl, acrylate, and combinations thereof.An exemplary polysiloxane is polydimethylsiloxane.

[0248] The polysiloxane preferably provides hydrophobic and hydrophilic portions. Typically, the hydrophobic and hydrophilic portions are at opposite ends of the polymer chain. In certain embodiments, the compatibilizer comprises an alkyl ester polydimethylsiloxane emulsion.

[0249] In some embodiments, the compatibilizer comprises a starch, such as a cationic starch, an amphoteric starch, a thermoplastic starch, or a combination thereof. Starch is a polymer of glucose.

[0250] Cationic starches carry a positive charge, which may be desirable when the nanocellulose (or other particulate) particles have a slightly negatively charged surface. Exemplary cationic starches may include quaternary ammonium cationic starches and tertiary amino cationic starches.

[0251] Amphoteric starches are modified starches that contain positively and negatively charged substituents. Exemplary amphoteric starches contain a quaternary ammonium cationic group and phosphate as the anionic group.

[0252] Thermoplastic starch is starch plasticized with a relatively low level (e.g., 15-30% by weight) of molecules capable of hydrogen bonding with the starch hydroxyl groups. The starch plasticizer can be water, a polyol (e.g., glycerol), pentaerythritol, a sugar alcohol (e.g., sorbitol), poly(oxyethylene), poly(oxypropylene), a nonionic surfactant, an anionic surfactant, or a combination thereof.

[0253] In some embodiments, the compatibilizer is selected at least in part based on the final composite, i.e., end-use application, which sometimes, but not necessarily, uses the same polymer as the polymer in the masterbatch.

[0254] Compatibilizers may have other functions besides promoting the dispersion of particulates. For example, in some embodiments, compatibilizers may function as plasticizers, density modifiers, viscosity modifiers, or toughness modifiers. Compatibilizers may also provide auxiliary attributes to the final material, such as color or texture.

[0255] In a preferred embodiment of the particulate masterbatch, the masterbatch is in the form of a solid powder. The powder may be pelletized into spheres, cylinders, plates, or other geometric shapes.

[0256] The particulate masterbatch may be produced in a pre-packaged form. The pre-packaging may be in small containers, tubes, vials, jars or bags, in pre-packaged materials that may be, for example, glass, plastic, coated paper, etc. In certain embodiments, the particulate masterbatch is provided in a powder form, such as a dry powder. In other embodiments, the particulate masterbatch is pelletized or compressed into various geometric shapes, such as spheres, beads, rods, cylinders, plates, etc. In some embodiments, the particulate masterbatch is part of a kit that includes the pre-packaged masterbatch along with instructions tailored for a particular composite system.

[0257] In other embodiments, the particulate masterbatch is in liquid form or in a masterbatch solvent such as water, a C1-C8 alcohol, a C2-C8 polyol, or combinations thereof. In certain embodiments, the masterbatch is in powder form but contains water or other solvent absorbed into the solids.

[0258] All processes disclosed herein may be carried out in batch, continuous or semi-continuous mode. Total feed volumes may vary widely, including laboratory, pilot, semi-commercial and commercial scales.

[0259] Nanocellulose can be characterized by unbound and bound moisture. This ratio is generally different for lignin-containing nanocellulose compared to non-lignin-containing nanocellulose, all other factors being equal. Thus, the configuration and operating parameters of the equipment can be adapted to the ratio of unbound to bound moisture in the system feed. In some embodiments, the centrifuge aims to remove unbound water, while the extruder can remove bound water by high shear forces in combination with thermal energy.

[0260] The present invention is applicable to a wide variety of nanocellulose materials. Nanocellulose can be produced by breaking down biomass into submicron cellulose nanofibrils or nanocrystals using chemical, mechanical, or a combination of chemical and mechanical means. Other methods of providing nanocellulose, such as bacterial nanocellulose and tunicate-derived nanocellulose, are also available.

[0261] Typically, the production of nanocellulose is carried out in two main stages. The first stage is the purification of the biomass to remove most of the non-cellulosic components in the biomass, such as lignin, hemicellulose, extractives and inorganic contaminants. This stage is typically carried out by conventional pulping and bleaching. For the production of cellulose nanofibrils, the second stage typically involves mechanical purification of the purified biomass fibers, with or without chemical or enzymatic treatment to reduce the amount of mechanical energy required. For cellulose nanocrystals, the second stage typically involves acid hydrolysis of the purified fibers, followed by high shear mechanical treatment.

[0262] Nanocellulose may be obtained by fractionation of lignocellulosic biomass in the presence of an acid catalyst, a solvent for lignin, and water to obtain a cellulosic-rich solids fraction, followed by mechanical treatment of the cellulosic-rich solids fraction to produce nanocellulose or its precursors. In some embodiments, the solvent for lignin is an aliphatic alcohol (e.g., ethanol) and the acid catalyst is a sulfur-containing compound selected from the group consisting of sulfur dioxide, sulfurous acid, sulfur trioxide, sulfuric acid, elemental sulfur, sulfonic acid, lignosulfonic acid, and combinations thereof.

[0263] Nanocellulose may be obtained from the AVAP® lignocellulosic biomass fractionation process. It has been found that very high crystallinity can be produced and maintained during the formation of nanofibers or nanocrystals without the need for an enzymatic or separate acid treatment step to hydrolyze the amorphous cellulose. High crystallinity can translate to mechanically strong fibers or good physical reinforcement properties, which is advantageous for, for example, composites, reinforcing polymers, and high strength spun fibers and fabrics.

[0264] In some embodiments, the nanocellulose comprises hydrophobic nanocellulose. In these or other embodiments, the nanocellulose comprises hydrophilic nanocellulose. In certain embodiments, the nanocellulose comprises lignin-containing cellulose nanocrystals (e.g., lignin-coated cellulose nanocrystals) and / or lignin-containing cellulose nanofibrils (e.g., lignin-coated cellulose nanofibrils).

[0265] In some embodiments, the nanocellulose material is at least partially hydrophobic due to the deposition of at least some lignin on the surface of the cellulose-rich solids (nanocellulose precursors). In these or other embodiments, the nanocellulose material is at least partially hydrophobic due to the deposition of at least some lignin on the surface of the nanocellulose material after mechanical refining.

[0266] In some embodiments, the acid is SO2 at a concentration of about 5% to about 30% by weight. In some embodiments, the fractionation temperature is about 130° C. to about 180° C. In some embodiments, the fractionation time is about 15 minutes to about 4 hours. The process can be controlled such that a portion of the solubilized lignin is purposefully deposited back onto the surface of the cellulosic-rich solids, thereby rendering the cellulosic-rich solids at least partially hydrophobic.

[0267] Process conditions may be employed that tend to promote deposition of lignin on the fibers, such as increased time and / or temperature, or reduced concentration of solvent for lignin. Alternatively, or in addition, one or more washing steps may be adapted to deposit at least some of the lignin that was solubilized during the initial fractionation. One approach is to wash with water rather than a solution of water and solvent. Since lignin is generally not soluble in water, it will begin to precipitate. Optionally, other conditions such as pH and temperature may be altered during fractionation, washing, or other steps to optimize the amount of lignin deposited on the surface. Optionally, the process of producing hydrophobic nanocellulose material may further include chemically modifying the lignin to increase the hydrophobicity of the nanocellulose material.

[0268] Alternatively, or additionally, nanocellulose may be obtained by fractionation of lignocellulosic biomass in the presence of steam or hot water, optionally with a fractionation catalyst (e.g., acetic acid), to obtain a cellulose-rich solids fraction, followed by mechanical refining of the cellulose-rich solids fraction to produce nanocellulose. These steps may be collectively referred to as hydrothermal mechanical treatment. The reaction solution for fractionation may consist essentially of steam or hot water. Note that "steam or hot water" refers to water in one or more phases determined by thermodynamics at a given temperature and pressure. The fractionation temperature may be from about 120°C to about 220°C, such as from about 150°C to 200°C. The water may be in the form of steam, superheated steam, supersaturated steam, or liquid pressurized water. In some embodiments, the fractionation step is carried out with a residence time of from about 1 minute to about 60 minutes, such as about 2, 2.5, 3, 3.5, 4, 5, 7.5, 10, 12.5, 15, 20, 25, 30, 35, 40, 45, 50, or 55 minutes.

[0269] In embodiments employing hydrothermal mechanical treatment, the cellulose-rich solids typically contain significant concentrations of lignin. Thus, these embodiments can be beneficial when hydrophobic nanocellulose is desired. Hydrothermal mechanical treatment can produce nanocellulose that can be referred to as nanolignocellulose due to its high lignin content. Nanolignocellulose can contain, on a bone dry, ash-free and acetyl-free basis, about 35% to about 80% by weight of cellulose nanofibrils, cellulose microfibrils, or a combination thereof, about 15% to about 45% by weight of lignin, and about 5% to about 20% by weight of hemicellulose. Of the lignin present, some may coat the nanocellulose particles, with the remaining lignin present inside the nanocellulose particles.

[0270] Nanocellulose is preferably obtained from lignocellulosic biomass. As used herein, "lignocellulosic biomass" means any material containing cellulose and lignin. Lignocellulosic biomass may also contain hemicellulose. It is possible to use a mixture of one or more types of biomass. In some embodiments, the biomass feedstock contains both lignocellulosic components (such as those mentioned above) in addition to a sucrose-containing component (e.g., sugar cane or energy sugar cane) and / or a starch component (e.g., corn, wheat, rice, etc.). Various moisture levels may be associated with the starting biomass. The biomass feedstock need not be relatively dry, but may be dry. Usually, the biomass is in the form of particulates or chips, but the particle size of the starting biomass is not critical.

[0271] Biomass feedstocks for forming nanocellulose can be selected from hardwoods, softwoods, forest waste, eucalyptus, industrial waste, pulp and paper waste, consumer waste, or combinations thereof. Some embodiments utilize agricultural residues including lignocellulosic biomass associated with food crops, annual grasses, energy crops, or other annually renewable feedstocks. Exemplary agricultural residues include, but are not limited to, corn stover, corn fiber, wheat straw, sugarcane bagasse, sugarcane straw, rice straw, oat straw, barley straw, miscanthus, energy sugarcane straw / residue, or combinations thereof.

[0272] Other sources of nanocellulose include bacterial nanocellulose, tunicate-derived nanocellulose, treatment of pulp with sulfuric acid, treatment of pulp with 2,2,6,6-tetramethylpiperidine-1-oxygen (TEMPO), or treatment of pulp with cellulase enzymes. In some embodiments, the nanocellulose employed herein is not bacterial nanocellulose, is not tunicate-derived, is not obtained from sulfuric acid hydrolysis, is not obtained from TEMPO, and / or is not obtained by enzymatic hydrolysis of lignocellulosic biomass or cellulose.

[0273] As intended herein, "nanocellulose" is broadly defined to include a wide range of cellulosic materials, including, but not limited to, microfibrillated cellulose, nanofibrillated cellulose, microcrystalline cellulose, nanocrystalline cellulose, and microparticulated or fibrillated dissolving pulp. In certain embodiments, nanocellulose comprises particles having at least one linear dimension (e.g., diameter) on the nanometer scale. In some embodiments, nanocellulose has particles with all average dimensions greater than 1 micron, such as certain microfibrillated cellulose.

[0274] "Nanofibrillated cellulose" or, equivalently, "cellulose nanofibrils" refers to cellulose fibers or regions containing nanometer-sized particles or fibers, or both micron-sized and nanometer-sized particles or fibers. "Nanocrystalline cellulose" or, equivalently, "cellulose nanocrystals" refers to cellulose particles, regions or crystals containing nanometer-sized domains, or both micron-sized and nanometer-sized domains. "Micron-sized" includes 1 μm to 100 μm, and "nanometer-sized" includes 0.01 nm to 1000 nm (1 μm). Larger domains (including long fibers) may also be present in any of these materials.

[0275] The specific size and shape of nanocellulose can range from nanometer scale to submicron scale in width and / or length. Cellulose nanofibers typically have dimensions of 5-20 nm width and 500-5000 nm length and contain both amorphous and crystalline domains of cellulose. Cellulose nanocrystals typically have widths of 3-8 nm and lengths of 100-500 nm and are predominantly crystalline. While these ranges and dimensions are typical, the invention encompasses all nanocellulose materials regardless of particle shape or size.

[0276] Some embodiments employ blends of nanocellulose crystals and fibrils. The blends of nanocellulose crystals and fibrils may contain 1% to 99% nanocellulose crystals and 99% to 1% nanocellulose fibrils, respectively. In various embodiments, the blends of nanocellulose crystals and fibrils contain 2%, 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95% or 98% (all weight percent) nanocellulose crystals, with the remainder of the nanocellulose being nanocellulose fibrils.

[0277] Some embodiments employ blends of cellulose nanofibrils and microfibrils. The blends of cellulose nanofibrils and cellulose microfibrils may contain 1% to 99% cellulose nanofibrils and 99% to 1% cellulose microfibrils, respectively. In various embodiments, the blends of cellulose nanofibrils and microfibrils contain 2%, 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95% or 98% (all by weight percent) cellulose nanofibrils, with the remainder being cellulose microfibrils.

[0278] One feature of nanocellulose blends is that nanocellulose fibrils are much larger than nanocellulose crystals, so a wide range of particle sizes exists. The width of the nanocellulose crystals can vary, for example, from about 2 nanometers to about 10 nanometers, or from about 3 nanometers to about 6 nanometers. The length of the nanocellulose crystals can vary, for example, from about 50 nanometers to about 500 nanometers, or from about 100 nanometers to about 350 nanometers. The width of the nanocellulose fibrils can vary, for example, from about 5 nanometers to about 100 nanometers, or from about 10 nanometers to about 50 nanometers. The length of the nanocellulose fibrils can vary, for example, from about 200 nanometers to about 10 microns, or from about 400 nanometers to about 3 microns. The average nanocellulose particle width in the blend can vary, for example, from about 3 nanometers to about 50 nanometers, such as from about 5 nanometers to about 30 nanometers. The average nanocellulose particle length in the blend can vary from about 50 nanometers to about 5 microns, such as from about 100 nanometers to about 2 microns.

[0279] In some variations, the nanocellulose is obtained by a process comprising: (a) providing a lignocellulosic biomass feedstock; (b) fractionating the feedstock in the presence of an acid, a solvent for lignin, and water to produce a cellulose-rich solids fraction and a liquid containing hemicellulose and lignin; (c) mechanically treating the cellulose-rich solids to form cellulose fibrils and / or cellulose crystals, thereby producing a nanocellulose material having at least 60% crystallinity (i.e., cellulose crystallinity); and (d) Recovering nanocellulose materials.

[0280] In some embodiments, the acid is selected from the group consisting of sulfur dioxide, sulfurous acid, sulfur trioxide, sulfuric acid, lignosulfonic acid, and combinations thereof, hi certain embodiments, the acid is sulfur dioxide.

[0281] Water for fractionation may be at least partially replaced by other polar solvents. Typically, nanocellulose is formed in an aqueous solution, but this is not strictly necessary. Biomass fractionation methods to form nanocellulose may in principle use polar solvents such as glycerol or ethanol instead of or in addition to water. Thus, although most of this disclosure refers to water as the primary or only polar solvent in the starting nanocellulose slurry, it will be understood that one or more polar solvents other than water may be utilized.

[0282] In some embodiments, during step (c), the rich cellulosic solids are treated with less than about 5000 kilowatt-hours of total mechanical energy per tonne of rich cellulosic solids, such as less than about 4000, 3000, 2000, or 1000 kilowatt-hours per tonne of rich cellulosic solids. Energy consumption may be measured in any other suitable units. An ammeter measuring the current drawn by the motors driving the mechanical treatment equipment is one way to obtain an estimate of the total mechanical energy.

[0283] The mechanical treatment in step (c) may employ one or more known techniques, including but not limited to kneading, grinding, crushing, sonication, or any other means that creates or releases nanofibrils and / or nanocrystals in cellulose. Essentially any type of mill or device that physically separates fibers may be utilized. Such mills are well known in the industry and include but are not limited to valley beaters, single-disk refiners, double-disk refiners, conical refiners, including both wide and narrow angles, cylinder refiners, homogenizers, microfluidizers, and other similar kneading or grinding devices. See, for example, Smook, Handbook for Pulp & Paper Technologists, Tappi Press, 1992; and Hubbe et al., "Cellulose Nanocomposites: A Review", BioResources 3(3), pages 929-980 (2008).

[0284] The extent of mechanical treatment may be monitored during the process by any of a number of means. Certain optical instruments are capable of providing continuous data relating to fiber length distribution and fraction of fines, either of which may be used to define the endpoint of the mechanical treatment step. Time, temperature and pressure may be varied during mechanical treatment. For example, in some embodiments, ultrasonic treatment at ambient temperature and pressure may be utilized for a period of about 5 minutes to 2 hours.

[0285] In some embodiments, a portion of the cellulose-rich solids are converted to nanofibrils while the remainder of the cellulose-rich solids are not fibrillized. In various embodiments, about 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, 95%, 99%, or substantially all of the cellulose-rich solids are fibrillated into nanofibrils.

[0286] In some embodiments, a portion of the nanofibrils are converted to nanocrystals while the remainder of the nanofibrils are not converted to nanocrystals. In various embodiments, about 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, 95%, 99%, or substantially all of the nanofibrils are converted to nanocrystals. During drying, a small amount of the nanocrystals may recombine to form nanofibrils.

[0287] After mechanical treatment, the nanocellulose material may be classified by particle size. A portion of the material may be subjected to another process, such as enzymatic hydrolysis, to produce glucose. Such material may, for example, have good crystallinity, but may not have the desired particle size or degree of polymerization.

[0288] Step (c) may further comprise treating the cellulosic-rich solids with one or more enzymes or one or more acids. When acids are utilized, they may be selected from the group consisting of sulfur dioxide, sulfurous acid, lignosulfonic acid, acetic acid, formic acid, and combinations thereof. Hemicellulose-related acids such as acetic acid or uronic acids may be utilized alone or in combination with other acids. Step (c) may also comprise treating the cellulosic-rich solids with heat. In some embodiments, step (c) does not utilize any enzymes or acids.

[0289] In step (c), if an acid is utilized, the acid may be a strong acid, such as, for example, sulfuric acid, nitric acid, or phosphoric acid. Weaker acids may be utilized at more severe temperatures and / or times. Enzymes that hydrolyze cellulose (i.e., cellulases) and, optionally, hemicellulose (i.e., have hemicellulase activity) may be employed in place of the acid in step (c), or, optionally, in a sequential fashion, before or after the acid hydrolysis.

[0290] In some embodiments, the process includes enzymatically treating the cellulosic-rich solids to hydrolyze amorphous cellulose. In other embodiments, or consecutively, before or after the enzyme treatment, the process may include acid treating the cellulosic-rich solids to hydrolyze amorphous cellulose.

[0291] In some embodiments, the process further comprises enzymatically treating the nanocrystalline cellulose. In other embodiments, or consecutively after or prior to the enzymatic treatment, the process further comprises acid treating the nanocrystalline cellulose.

[0292] If desired, an enzymatic treatment can be employed prior to, or optionally simultaneously with, the mechanical treatment, however, in preferred embodiments, no enzymatic treatment is required to hydrolyze the amorphous cellulose or weaken the fiber wall structure prior to isolation of the nanofibers.

[0293] Following mechanical treatment, the nanocellulose may be recovered. Separation of cellulose nanofibrils and / or nanocrystals may be achieved using equipment capable of disrupting the ultrastructure of the cell wall while preserving the integrity of the nanofibrils. For example, a homogenizer may be employed. In some embodiments, cellulose aggregate fibrils are recovered having component fibrils in the range of 1-100 nm width, where the fibrils are not completely separated from each other.

[0294] The process may further comprise bleaching the cellulose-rich solids prior to and / or as part of step (c). Alternatively, or additionally, the process may further comprise bleaching the nanocellulose material during and / or following step (c). Any known bleaching technique or sequence may be utilized, including enzymatic bleaching.

[0295] Optionally, the process further comprises hydrolyzing the amorphous cellulose to glucose in step (b) and / or step (c), recovering the glucose, and fermenting the glucose into a fermentation product. Optionally, the process further comprises recovering, fermenting, or further processing hemicellulosic sugars derived from the hemicellulose. Optionally, the process further comprises recovering, combusting, or further processing the lignin.

[0296] The nanocellulose material may comprise or consist essentially of nanofibrillated cellulose. The nanocellulose material may comprise or consist essentially of nanocrystalline cellulose. In some embodiments, the nanocellulose material may comprise or consist essentially of nanofibrillated cellulose and nanocrystalline cellulose.

[0297] In some embodiments, the crystallinity of the cellulose-rich solids (i.e., nanocellulose precursor material) is at least 60%, 61%, 62%, 63%, 64%, 65%, 66%, 67%, 68%, 69%, 70%, 71%, 72%, 73%, 74%, 75%, 76%, 77%, 78%, 79%, 80%, 81%, 82%, 83%, 84%, 85%, 86% or more. In these or other embodiments, the crystallinity of the nanocellulose material is at least 60%, 61%, 62%, 63%, 64%, 65%, 66%, 67%, 68%, 69%, 70%, 71%, 72%, 73%, 74%, 75%, 76%, 77%, 78%, 79%, 80%, 81%, 82%, 83%, 84%, 85%, 86% or more. Crystallinity may be measured using any known technique, such as X-ray diffraction and solid state diffraction. 13 C nuclear magnetic resonance can be used.

[0298] In some embodiments, the nanocellulose material is characterized by an average degree of polymerization of about 100 to about 3000, such as about 125, 150, 175, 200, 225, 250, 300, 400, 500, 600, 700, 800, 900, 1000, 1100, 1200, 1300, 1400, 1500, 2000, 2500, or 2600. For example, the nanocellulose material may be characterized by an average degree of polymerization of about 300 to about 700, or about 150 to about 250. The nanocellulose material, when in the form of nanocrystals, may have a degree of polymerization of less than 100, such as about 75, 50, 25, or 10. Some of the material may have a degree of polymerization of more than 3000, 4000, or 5000.

[0299] In some embodiments, the nanocellulose material is characterized by a single-peaked degree of polymerization distribution, while in other embodiments, the nanocellulose material is characterized by a two-peaked degree of polymerization distribution, such as a peak centered in the 150-250 range and another peak centered in the 300-700 range.

[0300] In some embodiments, the nanocellulose material is characterized by an average length-to-width aspect ratio of the particles of about 10 to about 1000, such as about 15, 20, 25, 35, 50, 75, 100, 150, 200, 250, 300, 400, or 500. Nanofibrils generally have a higher aspect ratio than nanocrystals. Nanocrystals may, for example, have a length range of about 100 nm to 500 nm and a diameter of about 4 nm, which corresponds to an aspect ratio of 25 to 125. Nanofibrils may have a length range of about 2000 nm and a diameter range of 5 to 50 nm, which corresponds to an aspect ratio of 40 to 400. In some embodiments, the aspect ratio is less than 50, less than 45, less than 40, less than 35, less than 30, less than 25, less than 20, less than 15, or less than 10.

[0301] In some embodiments, the nanocellulose contains less than 0.05% sulfur by weight, such as about 0.02% sulfur by weight or less with no detectable sulfur. In some embodiments, the nanocellulose does not contain sulfate half ester groups attached to the surface of the nanocellulose particles, as these groups can reduce the thermal stability of the nanocellulose.

[0302] The "thermal decomposition onset temperature" of a material is defined by thermogravimetric analysis of the material. Thermogravimetric analysis, also known as thermogravimetric analysis (TGA), is a technique that monitors the mass of a material as a function of temperature or time when a sample specimen is subjected to a controlled temperature program in a controlled atmosphere. Thermogravimetric analysis may utilize a PerkinElmer STA6000 Simultaneous Thermal Analyzer (London, UK). The abscissa (x-axis) is temperature and the ordinate (y-axis) is weight percent (%). A descending TGA heat curve indicates that weight loss is occurring. From the TGA heat curve, an extrapolated onset temperature can be calculated and represents the temperature at which weight loss begins. The extrapolated onset temperature is a reproducible temperature calculation and is specified for use by ASTM and ISO for TGA. The extrapolated onset point is the intersection of the tangent drawn at the point of maximum slope on the rise of the peak with the extrapolated baseline. This technique may be applied to nanocellulose or dispersants / desiccant agents.

[0303] For purposes herein, to determine the onset temperature of thermal decomposition of nanocellulose, samples are heated from 50° C. to 600° C. at a heating rate of 10° C. / min under nitrogen atmosphere with a flow rate of 40 mL / min using a PerkinElmer STA6000 Simultaneous Thermal Analyzer. Mass is measured as a function of temperature. Mass loss other than water loss indicates thermal decomposition of the material. The extrapolated onset temperature from the TGA graph is the estimated onset temperature of thermal decomposition of the nanocellulose or dispersion / desiccant.

[0304] In some preferred embodiments, the nanocellulose is characterized by an onset temperature of pyrolysis of about, or at least about, 300° C., 310° C., 320° C., or 330° C., such as in the case of BioPlus® cellulose nanocrystals or nanofibrils produced by acid catalysis, solvent for lignin, and water fractionation. In other embodiments, the nanocellulose is characterized by an onset temperature of pyrolysis of about 220° C. to about 300° C., such as about 225° C. for TEMPO-produced cellulose nanofibrils, or about 285° C. for sulfuric acid-produced cellulose nanocrystals.

[0305] Optionally, the nanocellulose itself is functionalized with one or more surface functional groups to produce nanocellulose derivatives. Such functionalization can be carried out, for example, to improve compatibility with matrix polymers or to impart special properties to the nanocellulose. Because nanocellulose has a high surface area and a high concentration of surface hydroxyl groups, virtually any desired surface functional group can be introduced by targeted surface modification.

[0306] For example, the nanocellulose derivative may be selected from the group consisting of nanocellulose esters, nanocellulose ethers, nanocellulose ether esters, alkylated nanocellulose compounds, crosslinked nanocellulose compounds, acid-functionalized nanocellulose compounds, base-functionalized nanocellulose compounds, and combinations thereof. Various types of nanocellulose functionalization or derivatization may be utilized, such as functionalization with polymers, chemical surface modification, functionalization with nanoparticles (i.e., nanoparticles other than nanocellulose), modification with inorganic or surfactants, or biochemical modification.

[0307] In some variations, the nanocellulose is obtained by a process comprising: (a) providing a lignocellulosic biomass feedstock; (b) fractionating the feedstock in the presence of an acid (such as SO2) or its salt and water to produce a cellulose-rich solids fraction and a liquid containing hemicellulose and lignin; (c) mechanically treating the cellulose-rich solids to form cellulose fibrils and / or cellulose crystals, thereby producing a nanocellulose material having at least 60% crystallinity (i.e., cellulose crystallinity); and (d) Recovering nanocellulose materials.

[0308] In some variations, the nanocellulose is obtained by a process comprising: (a) providing a lignocellulosic biomass feedstock; (b) fractionating the feedstock in the presence of water and a solvent for lignin to produce a cellulose-rich solids fraction and a liquid containing hemicellulose and lignin; (c) mechanically treating the cellulose-rich solids to form cellulose fibrils and / or cellulose crystals, thereby producing a nanocellulose material having at least 60% crystallinity (i.e., cellulose crystallinity); and (d) Recovering nanocellulose materials.

[0309] In some variations, the nanocellulose is obtained by a process comprising: (a) providing a lignocellulosic biomass feedstock; (b) fractionating the feedstock in the presence of steam or hot water to produce a cellulose-rich solids fraction and a liquid containing hemicellulose and lignin; (c) mechanically treating the cellulose-rich solids to form cellulose fibrils and / or cellulose crystals, thereby producing a nanocellulose material having at least 60% crystallinity (i.e., cellulose crystallinity); and (d) Recovering nanocellulose materials.

[0310] Dehydrated nanocellulose can be used in a wide range of end use applications. In many embodiments, nanocellulose is incorporated into a matrix material to form a nanocellulose-containing composite. Nanocellulose can be compounded to form a composite using a variety of equipment, including, but not limited to, single screw extruders, twin screw extruders, injection molding lines, compression molding lines, kneaders, calendars, rotor-stator dispersion mills, high shear mixers, stirred tanks, or in-line mixers.

[0311] The nanocellulose-containing composites can be 3D printed. Three-dimensional (3D) printing or additive manufacturing is the process of creating three-dimensional shaped objects using a dedicated printer. The printer receives instructions from a design file created on a computer with the aid of a 3D modeling program. The file or digital design of the object to be printed is then sliced ​​into a two-dimensional (2D) representation and sent to the printer. Layers of material are built up according to the information contained in the file; these layers continue to be stacked until the complete object is printed. Although the 3D printing process is significantly more time consuming and involves a significant capital investment compared to 2D printing, it offers a wide range of advantages, such as the ability to print, in principle, any geometric shape.

[0312] The degree of dispersion of nanocellulose in the final composite can be measured or assessed qualitatively. Dispersion is the inverse of agglomeration. If there is complete and homogeneous dispersion, there will be no agglomeration of particles. The present invention does not require complete dispersion such that every single nanoparticle is isolated from every other nanoparticle.

[0313] The degree of dispersion of nanocellulose may be measured or qualitatively assessed using techniques such as, for example, scanning electron microscopy, transmission electron microscopy, interference microscopy, confocal laser scanning microscopy, optical microscopy, small angle X-ray scattering, atomic force microscopy, dynamic light scattering, nanotomography, or thermogravimetric analysis.

[0314] The degree of dispersion of nanocellulose may also be measured or qualitatively assessed using a calibration technique in which a verified polymer with known nanocellulose dispersion is tested for a relevant property, and then a test sample is measured for the same property, which is correlated to the degree of dispersion of nanocellulose using a predetermined graph, formula, or look-up table.

[0315] In the composite product, when present, the dispersing / desiccant may be in the same phase as the nanocellulose, in the same phase as the matrix material, and / or in a separate phase. The dispersing / desiccant may be located between the nanocellulose particles and the matrix material. In some embodiments, the dispersing / desiccant surrounds the nanocellulose particles.

[0316] In some embodiments, the nanocellulose-containing composite product is configured as a catalyst, catalyst substrate, or co-catalyst, hi some embodiments, the nanocellulose-containing composite product is configured electrochemically to carry or store electrical current or voltage.

[0317] In some embodiments, the nanocellulose-containing composite product is incorporated into a filter, membrane, or other separation device.

[0318] In some embodiments, the nanocellulose-containing composite product is incorporated as an additive into a coating, paint, or adhesive, hi some embodiments, the nanocellulose-containing composite product is a cement additive.

[0319] Nanocellulose-containing composite products may include any of the disclosed compositions. Many composite products are possible. For example, the composite product may be selected from the group consisting of structures, foams, aerogels, carbon composites, films, coatings, coating precursors, current or voltage carriers, filters, membranes, catalysts, catalyst substrates, coatings or coating additives, paints or paint additives, adhesives or adhesive additives, inks or ink additives, cement additives, paper coatings or paper additives, thickeners, rheology modifiers, additives for drilling fluids, and combinations or derivatives thereof.

[0320] The nanocellulose-containing composite products provided herein are expected to have high oxygen barrier properties and affinity for wood fibers for applications in food packaging and printing papers, making them suitable as coating materials. Alternatively, or in addition, the nanocellulose-containing composite products may be incorporated into products, for example, to improve barrier properties or to improve nucleation.

[0321] The nanocellulose-containing composite products provided herein are suitable as additives for improving the durability of paints and protecting paints and varnishes from degradation caused by UV radiation.

[0322] The nanocellulose-containing composite products provided herein are suitable as thickeners in food and cosmetic products. Nanocellulose can be used as a thixotropic, biodegradable, dimensionally stable thickener (stable to temperature and salt addition). The nanocellulose-polymer composite products provided herein are suitable as Pickering stabilizers for emulsions and particle-stabilized foams. The large surface area of ​​nanocellulose combined with its biodegradability makes it an attractive material for highly porous, mechanically stable aerogels.

[0323] In other embodiments, the masterbatch product is ultimately incorporated into structures, foams, aerogels, carbon composites, films, coatings, coating precursors, current or voltage carriers, filters, membranes, catalysts, catalyst substrates, coating additives, paint additives, adhesive additives, cement additives, paper coatings, thickeners, rheology modifiers, additives for drilling fluids, and combinations or derivatives thereof.

[0324] Other applications suitable for the present invention include high strength spun fibers and fabrics, advanced composites, barrier films, paints, lacquers, adhesives, switchable optical devices, pharmaceuticals, drug delivery systems, bone replacements, dental restorations, paper, packaging, building products, food and cosmetic additives, and hydrogels.

[0325] Aerospace and transportation composites may benefit from the particulate masterbatches of the present disclosure. Automotive applications include nanocellulose composites with polypropylene, polyamides (e.g., nylon) or polyesters (e.g., PBT).

[0326] The strength enhancement from nanocellulose increases both bond area and bond strength for high strength, high bulk, high filler content paper and paperboard applications with enhanced moisture and oxygen barrier properties.

[0327] In some embodiments, the masterbatch is combined with a thickener or rheology modifier. For example, the masterbatch may be an additive in drilling or fracturing fluids, such as, but not limited to, oil recovery fluids and / or gas recovery fluids.

[0328] Masterbatches may generally be useful in any system that can benefit from the incorporation of a masterbatch. As discussed herein, the system may include, but is not limited to, polymers, oligomers, paper, paperboard, fiber and wood composites, emulsions, hydrogels, carbon, organic solids, inorganic solids, oils, organic liquids, inorganic liquids, cementitious materials (e.g., concrete or cement), minerals, ceramics, metals, metal alloys, glasses, or combinations thereof. The non-polymer matrix material may be, for example, an adhesive matrix, a battery electrode matrix, a bioink matrix, or an electronic ink matrix.

[0329] In this detailed description, reference has been made to several embodiments of the invention, as well as non-limiting examples relating to how the invention can be understood and practiced. Other embodiments that do not provide all of the features and advantages set forth herein may be utilized without departing from the spirit and scope of the invention. The invention incorporates routine experimentation and optimization of the methods and systems described herein. Such modifications and variations are believed to be within the scope of the invention, as defined by the claims.

[0330] All publications, patents, and patent applications cited in this specification are hereby incorporated by reference in their entirety as if each publication, patent, or patent application was specifically and individually indicated herein. International Publication No. 2020 / 160565 A1, published on August 6, 2020, is incorporated by reference herein. International Publication No. 2020142793 A1, published on July 9, 2020, is incorporated by reference herein.

[0331] Where the methods and steps described above refer to certain events occurring in a certain order, those skilled in the art will recognize that the order of certain steps may be altered and that such alterations are in accordance with variations of the invention. In addition, certain steps may be performed simultaneously in parallel processes where possible, as well as sequentially.

[0332] Thus, to the extent there are modifications of the present invention which are within the spirit of this disclosure or equivalent to the invention found in the appended claims, it is intended that this patent cover those modifications as well. The present invention should be limited only by what is claimed.

Claims

1. 1. A process for forming a particulate masterbatch comprising: (a) providing a plurality of microparticles; (b) optionally introducing the plurality of microparticles and a pH adjuster into a first mixing unit; (c) transferring the aqueous polymer latex and the plurality of microparticles from step (a) or, if performed, from step (b), to a second mixing unit, thereby producing a microparticle-latex mixture comprising water; (d) optionally transferring the particulate-latex mixture and the first process additive to a third mixing unit; (e) transferring the particulate-latex mixture to a homogenizer, thereby producing a homogenized particulate-latex mixture; (f) optionally, transferring the homogenized particulate-latex mixture to a centrifuge to remove a first portion of the water, thereby producing a dehydrated and homogenized particulate-latex mixture; and (g) transferring the dewatered and homogenized particulate-latex mixture (or the homogenized particulate-latex mixture if step (f) is not performed) to a screw mixer configured to remove a second portion of the water, thereby producing a particulate masterbatch. wherein steps (a), (c), (e), (f) and (g) are performed substantially sequentially.

2. 10. The process of claim 1, wherein steps (b) and (d) are performed and steps (a) through (g) are performed substantially sequentially.

3. 3. The process of claim 1 or 2, wherein the plurality of particulates are first introduced into a premixing unit (i) prior to step (b), if performed, or (ii) prior to step (c).

4. 3. The process of claim 1 or 2, wherein the plurality of particulates is first slurried prior to step (b).

5. 10. The process of claim 1, wherein step (f) utilizes heat to facilitate water removal.

6. 10. The process of claim 1, wherein step (f) utilizes preheating of the homogenized particulate-latex mixture to facilitate water removal.

7. 10. The process of claim 1, wherein the screw mixer is a twin-screw extruder.

8. 8. The process of claim 7, wherein the twin-screw extruder is configured with multiple extruder zones that are independently temperature controlled and multiple suction vents that facilitate removal of the second portion of water.

9. 10. The process of claim 1, wherein the particulate masterbatch is characterized by a dispersion index of at least 50.

10. 10. The process of claim 1, wherein the particulate masterbatch is characterized by a dispersion index of at least 75.

11. 10. The process of claim 1, wherein the particulate masterbatch is characterized by a dispersion index of at least 90.

12. 10. The process of claim 1, wherein the process does not employ a polymeric latex coagulant.

13. 10. The process of claim 1, wherein the plurality of particulates comprises biomass-derived particulates selected from the group consisting of cellulose, nanocellulose, hemicellulose, nanohemicellulose, lignin, nanolignin, nanolignocellulose, and combinations thereof.

14. 10. The process of claim 1, wherein the plurality of particulates comprises particulates selected from the group consisting of silica, alumina, clay, nanoclay, zeolite, ceramic, metal, glass, polymer, and combinations thereof.

15. 10. The process of claim 1, wherein the plurality of particulates comprises carbonaceous particulates selected from the group consisting of graphite, graphene, activated carbon, carbon nanotubes, carbon fiber, biochar, coke, nanodiamonds, and combinations thereof.

16. 10. The process of claim 1, wherein the plurality of particulates comprises at least two types of particulates, and at least one type of particulate is slurried prior to step (b).

17. 1. A process for forming a particulate masterbatch comprising: (a) providing a plurality of particulates in the form of a particulate slurry comprising water; (b) optionally introducing the particulate slurry and a first process additive into a first mixing unit, the first process additive comprising a pH adjuster; (c) optionally transferring the particulate slurry and a second process additive to a second mixing unit; (d) optionally, transferring the particulate slurry to a homogenizer; (e) optionally, transferring the particulate slurry to a centrifuge to remove a first portion of the water; (f) transferring the particulate slurry, polymer solids, and optionally a third process additive to a screw mixer configured to remove a second portion of the water, thereby producing a particulate masterbatch. wherein step (a), any of steps (b) through (e), and step (f) are performed substantially sequentially.

18. 18. The process of claim 17, wherein steps (b), (c), (d), and (e) are performed, and steps (a) through (f) are performed substantially sequentially.

19. 19. The process of claim 17 or 18, wherein the plurality of particulates are first introduced into a premixing unit prior to step (b).

20. 19. The process of claim 17 or 18, wherein in the premixing unit, the plurality of particulates are slurried with water.

21. 20. The process of claim 17, wherein step (f) utilizes heat to facilitate water removal.

22. 20. The process of claim 17, wherein step (f) utilizes preheating of the particulate slurry to facilitate water removal.

23. 18. The process of claim 17, wherein the screw mixer is a twin-screw extruder.

24. 24. The process of claim 23, wherein the twin-screw extruder is configured with multiple independently temperature controlled extruder zones and multiple suction vents to facilitate removal of the second portion of water.

25. 20. The process of claim 17, wherein the particulate masterbatch is characterized by a dispersion index of at least 50.

26. 18. The process of claim 17, wherein the particulate masterbatch is characterized by a dispersion index of at least 75.

27. 20. The process of claim 17, wherein the particulate masterbatch is characterized by a dispersion index of at least 90.

28. 20. The process of claim 17, wherein the process does not employ a polymeric latex coagulant.

29. 18. The process of claim 17, wherein the plurality of particulates comprises biomass-derived particulates selected from the group consisting of cellulose, nanocellulose, hemicellulose, nanohemicellulose, lignin, nanolignin, nanolignocellulose, and combinations thereof.

30. 20. The process of claim 17, wherein the plurality of particulates comprises particulates selected from the group consisting of silica, alumina, clay, nanoclay, zeolite, ceramic, metal, glass, polymer, and combinations thereof.

31. 20. The process of claim 17, wherein the plurality of particulates comprises carbonaceous particulates selected from the group consisting of graphite, graphene, activated carbon, carbon nanotubes, carbon fiber, biochar, coke, nanodiamonds, and combinations thereof.

Images