Biodegradable cellulose ester microparticles and systems and methods for producing them

Abstract

A system and method for producing cellulose ester (CE) microparticles are provided. The CE microparticles are produced by grinding initial CE particles having an average particle size of at least 75 microns down to a D50 particle size in the range of 0.5 to 50 microns. The resulting microparticles are biodegradable and have a solidity and / or tactile quality that is acceptable for use as an economical alternative to conventional plastic microbeads.

Description

[Technical Field]

[0001] Microbeads are typically spherical plastic particles with a diameter of less than 1 millimeter (mm). These particles may be found in consumer products such as personal care products and cosmetics. Many of these microbead-containing products are designed to be applied and then washed or rinsed off the user's body. When microbead-containing products are washed or rinsed off the user's body, the particles are released into drains and received by municipal water treatment plants. In the past, many known microbeads were formed from plastic or polymer materials, such as polyethylene, polypropylene, polymethyl methacrylate, nylon, and polyurethane. These materials generally have limited biodegradability. Furthermore, the small size of the particles limits their ability to be captured by water treatment plants, and as a result, the particles may be released from the plants into larger bodies of water (e.g., rivers, seas, and oceans). Once in these larger bodies of water, plastic or polymer microbeads can be ingested by wildlife or cause other environmental concerns. Therefore, the possibility of producing microbead particles from more environmentally friendly materials has recently been explored. However, consumers tend to have high expectations regarding the personal care products and / or cosmetics they use, including those containing micron-sized particles. For example, consumers expect these personal care products and cosmetics to exhibit certain optical properties that allow them to blend with natural skin tone and easily conceal any undesirable blemishes. [Background technology]

[0002] Therefore, it is desirable to economically produce biodegradable microparticles that meet environmental and consumer expectations, particularly with regard to the optical properties of personal care products and cosmetics. [Overview of the project]

[0003] This specification provides a method for producing biodegradable cellulose ester (CE) microparticles. This method includes providing initial CE particles having an average particle size of at least 75 microns and grinding the initial CE particles to thereby form CE microparticles having a D50 particle size within the range of 0.5 to 50 microns.

[0004] Also, this specification provides a system for producing cellulose ester (CE) microparticles. This system includes a source of initial CE particles, a compressor for generating compressed gas, a jet mill for receiving the initial CE particles and reducing their size to CE microparticles, and a feed system for supplying the initial CE particles to the jet mill. The jet mill is supplied with a first portion of the compressed gas from the compressor, and the feed system is supplied with a second portion of the compressed gas from the compressor.

[0005] Also, this specification provides biodegradable cellulose ester (CE) microparticles containing at least one CE, wherein the CE microparticles have a D50 particle size in the range of 0.5 to 50 microns and the CE microparticles exhibit at least 50 percent biodegradability in 60 days by the OECD 301B test method.

Brief Description of the Drawings

[0006] [Figure 1] It is a schematic diagram of an exemplary process for producing cellulose ester microparticles. [Figure 2] It is a schematic diagram of an exemplary system for producing cellulose ester microparticles. [Figure 3] It is a schematic diagram of an alternative system for producing cellulose ester microparticles, which includes separate packaging stations for crude and fine products. [Figure 4] It is a schematic diagram of an exemplary separator that can be used in the system shown in FIGS. 3 - 4.

Modes for Carrying Out the Invention

[0007] This disclosure relates to a system and method for producing cellulose ester (CE) microparticles. The CE microparticles are produced by milling (e.g., jet milling, jet-milling) a biodegradable CE raw material. The milling is carried out under process conditions that produce micron-sized CE particles of desirable quality, making them suitable as a replacement for conventional microbeads in certain consumer products. The CE microparticles may exhibit characteristics such as enhanced solidity and / or tactile properties, thereby making jet-milled microparticles generally indistinguishable from conventional microbeads from a consumer's perspective. These qualities, along with the biodegradability of CE, make the CE microparticles produced herein desirable for use in personal care products, cosmetics, and the like.

[0008] The present invention can be more readily understood by referring to the following detailed description of the invention and examples provided herein. It should be understood that this disclosure is not limited to, and therefore may vary, the specific methods, formulations, and conditions described. It should also be understood that the terms used herein are solely for the purpose of describing, and not intended to limit, specific aspects of the disclosed embodiments.

[0009] A value may be expressed as "about" or "approximately" a given number. Similarly, a range may be expressed herein as "about" one particular value to and / or "about" another particular value. Where such a range is expressed, another aspect includes from one particular value to and / or other particular values. Similarly, where a value is expressed as an approximation using the preceding "about," it is understood that a particular value forms another aspect.

[0010] As used herein, the terms "a," "an," and "the" mean one or more.

[0011] As used herein, when the term "and / or" is used in a list of two or more items, it means that any one of the listed items can be used by itself, or any combination of two or more of the listed items can be used. For example, if a composition is described as containing components A, B, and / or C, the composition may contain A only, B only, C only, a combination of A and B, a combination of A and C, a combination of B and C, or a combination of A, B, and C.

[0012] As used herein, the terms “comprising,” “comprises,” and “comprise” are open-ended transitional clauses used to move the subject listed before the term to one or more elements listed after the term, and the elements listed after the transitional clause are not necessarily the only elements that constitute the subject.

[0013] As used herein, the terms “having,” “has,” and “have” have the same open-ended meaning as “comprising,” “comprises,” and “comprise” as defined above.

[0014] As used herein, the terms “including,” “includes,” and “include” have the same open-ended meaning as “comprising,” “comprises,” and “comprise” as defined above.

[0015] As used herein, “mixed cellulose ester” refers to a cellulose ester having at least two different ester substituents on a single cellulose ester polymer chain.

[0016] The term "degree of substitution" is used to describe the average level of substituent substitution ("AGU") per anhydrous glucose unit. Generally, conventional cellulose contains three hydroxyl groups in each substituteable AGU. Therefore, the DS can have a value between 0 and 3. However, low molecular weight cellulose mixed esters may have a total degree of substitution slightly greater than 3 due to the contribution of terminal groups. Low molecular weight cellulose mixed esters will be discussed in more detail later in this disclosure. Since the DS is a statistical mean, a value of 1 does not guarantee that every AGU has only one substituent. In some cases, there may be unsubstituted anhydrous glucose units, some with two substituents, some with three, and often the value is a non-integer. Total DS is defined as the average number of all substituents per anhydrous glucose unit. The degree of substitution per AGU may also mean specific substituents, such as hydroxyl, acetyl, butyryl, or propionyl. Furthermore, the degree of substitution may specify a given hydroxyl based on the carbon units of the anhydrous glucose unit.

[0017] The degree of substitution is hydroxyl, i.e., DS OH When referring to this, the standard is the average hydroxyl group per unsubstituted anhydrous glucose. As a result, DS OH This is not used in the calculation of the total degree of substitution.

[0018] The description of this invention uses numerical ranges to quantify specific parameters relating to the invention. Where numerical ranges are provided, it should be understood that such ranges should be interpreted as providing literal support for claims that enumerate only the lower limit of the range, as well as claims that enumerate only the upper limit of the range. For example, a disclosed numerical range of 10 to 100 provides literal support for claims that enumerate "greater than 10" (no upper limit) and claims that enumerate "less than 100" (no lower limit).

[0019] This specification uses specific numerical values ​​to quantify certain parameters related to the present invention, where these specific numerical values ​​are not an explicit part of a numerical range. It should be understood that each specific numerical value provided herein is to be interpreted as providing literal support for a broad range, an intermediate range, and a narrow range. The broad range associated with each specific numerical value is 60 percent of the value plus or minus, rounded to two significant figures. The intermediate range associated with each specific numerical value is 30 percent of the value plus or minus, rounded to two significant figures. The narrow range associated with each specific numerical value is 15 percent of the value plus or minus, rounded to two significant figures. For example, if a specific temperature of 62°F is described herein, such description literally supports a broad numerical range and an intermediate numerical range of 25°F to 99°F (62°F + / - 37°F). For example, these ranges consist of narrow numerical ranges of 43°F to 81°F (62°F ± 19°F) and 53°F to 71°F (62°F ± 9°F). These broad, intermediate, and narrow numerical ranges should apply not only to specific values ​​but also to the differences between these specific values. Therefore, if the specification describes a first pressure of 110 psi and a second pressure of 48 psia (a difference of 62 psi), the broad, intermediate, and narrow ranges of the pressure difference between these two flows would be 25 to 99 psi, 43 to 81 psi, and 53 to 71 psi, respectively.

[0020] Throughout this application, where any patent or publication is referenced, the entirety of the disclosures of those references is intended to be incorporated by reference to this application to more fully explain the state of the art to which the present invention relates, to the extent that such disclosures are not inconsistent with the present invention.

[0021] Referring here to Figure 1, a system 100 is illustrated in which cellulose 102, solvent 104, and acylating agent 106 are combined in a cellulose ester (CE) production facility 108 to produce a CE product stream 110. The CE product stream 110 may be in one or more forms of slurry, wet cake, powder, flake, and pellet. The CE in the CE product stream 110 is solid and is then ground to produce CE fine particles 112, as will be described in more detail below.

[0022] If the CE product stream 110 is in the form of a relatively dry (e.g., less than 10 wt% moisture) powder, flakes, and / or pellets, the CE product stream 110 may be directly introduced from the CE production unit 108 to the dry grinding unit 114. The powder, flakes, and / or pellets may then be ground in the dry grinding unit 114 to the desired average particle size to produce CE fine particles 112. The dry grinding unit 114 may be, for example, a jet mill or a mechanical mill. Suitable examples of mechanical mills include ball mills, rod mills, hammer mills, pin mills, and cryogenic mills.

[0023] If the CE product stream 110 is in the form of relatively dry flakes and / or pellets (e.g., with less than 10% by weight of water), the CE product stream 110 may first be reduced in size within a size reduction unit 113 before being ground in a dry grinding unit 114. The flakes and / or pellets may then be ground in the dry grinding unit 114 to a desired average particle size to produce CE fine particles 112. Examples of suitable size reduction units 13 include mechanical mills such as ball mills, rod mills, hammer mills, pin mills, and cryogenic mills.

[0024] If the CE product stream 110 is in the form of a slurry (for example, more than 50 weight percent liquid), the CE product stream 110 may first be dehydrated in a dehydration unit 118 to produce a wet cake 120, and then the wet cake 120 may be dried in a drying unit 122 to produce dried CE particles 124. The dried CE particles 124 may then be ground to a desired average particle size in a dry grinding unit 114 to produce fine CE particles 112.

[0025] In another embodiment, the slurry from the CE generation equipment 108 is dewatered in a dewatering unit 118 to produce a wet cake 126. The wet cake 126 may then be pulverized in a wet pulverizing unit 116 to produce a pulverized cake 128. The pulverized cake 128 may then be dried in a drying unit 130 to produce CE fine particles 112 from the solid content of the pulverized cake 128.

[0026] If the CE product stream 110 is in the form of a wet cake (e.g., 10-50 weight percent liquid), the CE product stream 110 may be directly introduced from the CE generation equipment 108 to the wet grinding unit 114. The wet cake may then be ground in the wet grinding unit 116 to produce a ground cake 128. The ground cake 128 may then be dried in unit 130 to produce CE fine particles 112 from the solid content of the ground cake 128. Alternatively, the wet cake CE product stream from the CE generation equipment 108 may be sent to the drying unit 122 to produce dried CE particles 124. The dried CE particles 124 may then be subjected to dry grinding in the dry grinding unit 114 to produce CE fine particles 112.

[0027] In one embodiment, or in combination with any embodiment referred to herein, one or more additives may be introduced before, during, or after grinding in the dry grinding unit 114 or the wet grinding unit 116. Examples of additives include those that improve grinding or enhance the performance of the final CE microparticles. For example, zinc stearate at any point during the process improves the dispersion of CE microparticles in the final formulation (i.e., prevents aggregation). Furthermore, plasticizers may be added at any point during the process to lower the glass transition temperature of the cellulose ester. Finally, after grinding, the CE microparticles may be brought into contact with a surfactant to improve the optical properties of the CE microparticles. Furthermore, the ground CE microparticles may be subjected to a spheroidizing step after grinding to increase the spheroidity of the CE microparticles. Spheroidizing can be achieved, for example, by dropping the CE microparticles into hot air.

[0028] Cellulose ester The cellulose ester in the CE product stream 110 may be cellulose diacetate ("CDA"), mixed cellulose ester ("MCE"), or a combination of CDA and one or more MCEs. Examples of MCEs include cellulose acetate butyrate ("CAB") and cellulose acetate propionate ("CAP").

[0029] In general, the cellulose esters described herein can be produced by any method known in the art, such as in a CE production facility 108. An example of a process for producing cellulose esters is taught in Kirk-Othmer, Encyclopedia of Chemical Technology, 5th Edition, Vol. 5, Wiley-Interscience, New York (2004), pp. 394-444, the disclosure of which is incorporated by reference throughout. Cellulose (i.e., cellulose 102), which is the starting material for producing cellulose esters, can be obtained from various grades and sources, such as cotton linters, softwood pulp, hardwood pulp, corn fiber, and other agricultural sources, as well as bacterial cellulose.

[0030] One method for producing cellulose esters is by esterification. In such a method, cellulose is mixed with a suitable organic acid, acid anhydride, and / or catalyst, and then converted to cellulose triester. Next, a water-acid mixture may be added to the cellulose triester to carry out ester hydrolysis, and this may be filtered to remove gel particles or fibers. Water is added to the mixture to precipitate the cellulose ester. Then, as described above, the cellulose ester may be washed with water to remove reaction byproducts, and then dehydrated and dried.

[0031] Suitable acylation reagents for use herein include, but are not limited to, alkyl or aryl carboxylic acid anhydrides, carboxylic acid halides, and / or carboxylic acid esters containing the alkyl or aryl group described above, which are suitable for use as acyl substituents of the substituted cellulose esters described herein. Suitable carboxylic acid anhydrides include, but are not limited to, acetic anhydride, propionic anhydride, butyric anhydride, pivaloyl anhydride, benzoic acid anhydride, and naphthoyl anhydride. Suitable carboxylic acid halides include, but are not limited to, acetyl, propionyl, butyryl, pivaloyl, benzoyl, and naphthoyl chlorides or bromides. Suitable carboxylic acid esters include, but are not limited to, acetyl, propionyl, butyryl, pivaloyl, benzoyl, and naphthoyl methyl esters. In one or more embodiments, the acylation reagent may be one or more carboxylic acid anhydrides selected from the group consisting of acetic anhydride, propionic anhydride, butyric anhydride, pivaloyl anhydride, benzoyl anhydride, and naphthoyl anhydride.

[0032] In various embodiments, the hydrolyzed cellulose triesters may have three substituents independently selected from alkanoyls having 2 to 12 carbon atoms. Examples of cellulose triesters include cellulose triacetate, cellulose trippropionate, cellulose tributyrate, or mixed triesters of cellulose, such as cellulose acetate propionate and cellulose acetate butyrate. These cellulose triesters can be prepared by a number of methods known to those skilled in the art. For example, cellulose triesters can be prepared by heterogeneous acylation of cellulose in a mixture of carboxylic acid and anhydride in the presence of a catalyst such as H2SO4. Cellulose triesters can also be prepared by homogeneous acylation of cellulose dissolved in a suitable solvent such as LiCl / DMAc or LiCl / NMP.

[0033] After esterification of cellulose to triester, some of the acyl substituents may be removed by hydrolysis or alcohol decomposition to obtain a secondary cellulose ester. Alternatively, the second cellulose ester may be prepared directly without hydrolysis by using a limited amount of acylation reagent. This process is particularly useful when the reaction is carried out in a solvent that dissolves cellulose.

[0034] The cellulose esters prepared in this way generally have the following structure: [ka] In the formula, R 2 , R 3 , and R 6 is hydrogen (however, R 2 , R 3 , and R 6 Alkyl-acyl groups (which are not hydrogen at the same time), and / or aryl-acyl groups (such as those mentioned above) that are bonded to cellulose via ester bonds.

[0035] The degree of polymerization (“DP”) of the cellulose ester prepared by these methods can be at least 10. In other embodiments, the DP of the cellulose ester can be at least 50, at least 100, or at least 250. In other embodiments, the DP of the cellulose ester can be in the range of about 5 to about 100, or in the range of about 10 to about 50.

[0036] In a first aspect, this application relates to a mixed ester cellulose ester (“MCE”) having: (1) a plurality of acetyl substituents; (2) a plurality of propionyl substituents; and (3) a plurality of hydroxyl substituents, where: the MCE has an average degree of substitution (“ DSAc ”) for the acetyl substituents of 0.1 to 2.3, the MCE has an average degree of substitution (“DS Pr ”) for the propionyl substituents of 0.1 to 1.2, and the MCE has an average degree of substitution (“DS OH ”) for the hydroxyl substituents of 0.6 to 2.8.

[0037] In one embodiment, or in combination with any other embodiment, class or subclass of this first aspect, DS Ac is at least 0.1, at least 0.2, at least 0.3, at least 0.4, at least 0.5, at least 0.6, at least 0.7, at least 0.8, at least 0.9, at least 1.0, at least 1.1, at least 1.2, at least 1.3, at least 1.4, at least 1.5, at least 1.6, at least 1.7, at least 1.8, at least 1.9, or at least 2.0. Additionally, or alternatively, DS Ac is less than 2.3, less than 2.2, less than 2.1, less than 2.0, less than 1.9, less than 1.8, less than 1.7, less than 1.6, less than 1.5, less than 1.4, less than 1.3, less than 1.2, less than 1.1, less than 1.0, less than 0.9, less than 0.8, less than 0.7, less than 0.5, less than 0.4, or less than 0.3.

[0038] In one embodiment, or in combination with any other embodiment, class, or subclass of this first embodiment, DS Ac This refers to 0.6~2.2, or 0.6~2.1, or 0.6~2.0, or 0.6~1.9, or 0.6~1.8, or 0.7~2.3, or 0.7~2.2, or 0.7~2.1, or 0.7~2.0, or 0.7~1.9, or 0.8~2.3, or 0.8~2.2, or 0.8~2.1, or 0.8~2.0, or 0.8~1.9, or 0.9~2.3, or 0.9~2.2, or 0.9~2.1, or 0.9~2.0, or 0.9~1.9, or 1.0~2.3, or 1.0~ 2.2, or 1.0-2.1, or 1.0-2.0, or 1.0-1.9, or 1.1-2.3, or 1.1-2.2, or 1.1-2.1, or 1.1-2.0, or 1.1-1.9, or 1.2-2.3, or 1.2-2.2, or 1.2-2.1, or 1.2-2.0, or 1.2-1.9, or 0.6-1.5, or 0.6-1.3, or 0.6-1.1, or 0.6-0.9, or 0.7-1.5, or 0.7-1.3, or 0.7-1.1, or 0.7-0.9.

[0039] In one embodiment, or in combination with any other embodiment, class, or subclass of this first embodiment, DS Pr is at least 0.1, at least 0.2, at least 0.3, at least 0.4, at least 0.5, at least 0.6, at least 0.7, at least 0.8, at least 0.9, at least 1.0, at least 1.1, at least 1.2, at least 1.3, or at least 1.4. Additionally or alternatively, DS Pr This is less than 1.5, less than 1.4, less than 1.3, less than 1.2, less than 1.1, less than 1.0, less than 0.9, less than 0.8, less than 0.7, less than 0.5, less than 0.4, or less than 0.3.

[0040] In one embodiment, or in combination with any other embodiment, class, or subclass of this first embodiment, DS PrThis refers to 0.1~0.9, or 0.1~0.85, or 0.1~0.8, or 0.1~0.75, or 0.1~0.7, or 0.1~0.6, or 0.1~0.5, or 0.1~0.4, or 0.15~0.95, or 0.15~0.9, or 0.15~0.85, or 0.15~0.8, or 0.15~0.75, or 0.15~0.7, or 0.15~0.65, or 0.2~0.95, or 0.2~0.9, or 0.2~0.85, or 0.2 ~0.8, or 0.2~0.75, or 0.2~0.7, or 0.2~0.65, 0.25~0.95, or 0.25~0.9, or 0.25~0.85, or 0.25~0.85, or 0.25~0.85, or 0.25~0.8, or 0.25~0.75, or 0.25~0.7, or 0.25~0.65, or 0.3~0.95, or 0.3~0.9, or 0.3~0.85, or 0.3~0.8, or 0.3~0.75, or 0.3~0. 7, or 0.3~0.85, or 0.3~0.85, or 0.3~0.75, or 0.3~0.7, or 0.3~0.65, or 0.35~0.95, or 0.35~0.9, or 0.35~0.85, or 0.35~0.8, or 0.35~0.75, or 0.35~0.7, or 0.35~0.65, or 0.4~0.95, or 0.4~0.9, or 0.4~0.85, or 0.4~0.8, or 0.4~0.75, or 0.4~0.7 Or 0.4~0.65, or 0.45~0.95, or 0.45~0.9, or 0.45~0.85, or 0.45~0.8, or 0.45~0.75, or 0.45~0.7, or 0.45~0.65, or 0.5~0.95, or 0.5~0.9, or 0.5~0.85, or 0.5~0.8, or 0.5~0.75, or 0.5~0.7, or 0.5~0.65, or 0.1~0.9, or 0.1~0.85, or 0.1~0.8.

[0041] In one embodiment, or in combination with any other embodiment, class, or subclass of this first embodiment, DS OHis at least 0.6, at least 0.7, at least 0.8, at least 0.9, at least 1.0, at least 1.1, at least 1.2, at least 1.3, at least 1.4, at least 1.5, at least 1.6, at least 1.7, at least 1.8, at least 1.9, at least 2.0, at least 2.1, at least 2.2, at least 2.3, at least 2.4, at least 2.5, or at least 2.6. Additionally or alternatively, DS OH This is less than 2.8, less than 2.7, less than 2.6, less than 2.5, less than 2.4, less than 2.3, less than 2.2, less than 2.1, less than 2.0, less than 1.9, less than 1.8, less than 1.7, less than 1.6, less than 1.5, less than 1.4, less than 1.3, less than 1.2, less than 1.1, less than 1.0, less than 0.9, or less than 0.8.

[0042] In one embodiment, or in combination with any other embodiment, class, or subclass of this first embodiment, DS OHThis refers to 0.5~1.5, or 0.5~1.45, or 0.5~1.40, or 0.5~1.35, or 0.5~1.30, or 0.5~1.25, or 0.5~1.2, or 0.5~1.15, or 0.5~1.1, or 0.5~1.05, or 0.5~1.0, or 0.5~0.95, or 0.5~0.9, or 0.55~1.5, or 0.55~1.45, or 0.55~1.40, or 0.55~ 1.35, or 0.55~1.30, or 0.55~1.25, or 0.55~1.2, or 0.55~1.15, or 0.55~1.1, or 0.55~1.05, or 0.55~1.0, or 0.55~0.95, or 0.55~0.9, or 0.6~1.5, or 0.6~1.45, or 0.6~1.40, or 0.6~1.35, or 0.6~1.30, or 0.6~1.25, or 0.6~ 1.2, or 0.6~1.15, or 0.6~1.1, or 0.6~1.05, or 0.6~1.0, or 0.6~0.95, or 0.6~0.9, or 0.65~1.5, or 0.65~1.45, or 0.65~1.40, or 0.65~1.35, or 0.65~1.30, or 0.65~1.25, or 0.65~1.20, or 0.65~1.15, or 0.65~1.1, or 0.65~ The values ​​are 1.05, or 0.65-1.0, or 0.65-0.95, or 0.65-0.9, or 0.7-1.5, or 0.7-1.45, or 0.7-1.40, or 0.7-1.35, or 0.7-1.30, or 0.7-1.25, or 0.7-1.2, or 0.7-1.15, or 0.7-1.1, or 0.7-1.05, or 0.7-1.0, or 0.7-0.95, or 0.7-0.9.

[0043] In one embodiment, or in combination with any other embodiment, class, or subclass of this first embodiment, DS Pr and DS AcThe sum of these values ​​is 1.9-2.44, or 1.9-2.0, or 1.9-2.1, or 1.9-2.2, or 1.9-2.3, or 2.0-2.44, or 2.0-2.1, or 2.0-2.2, or 2.0-2.3, or 2.1-2.44, or 2.1-2.2, or 2.1-2.3, or 2.2-2.44, or 2.2-2.3.

[0044] In one embodiment, or in combination with any other embodiment, class, or subclass of this first embodiment, the mixed cellulose ester has a hydroxyl substituent to acetyl substituent ratio of at least 0.4:1, at least 0.5:1, at least 0.6:1, at least 0.7:1, at least 0.8:1, at least 0.9:1, at least 1:1, at least 1.1:1, at least 1.2:1, at least 1.3:1, at least 1.4:1, at least 1.5:1, at least 1.6:1, at least 1.7:1, at least 1.8:1, at least 1.9:2, or at least 2:1. Alternatively, this mixed cellulose ester may have a hydroxyl substituent to acetyl substituent ratio of less than 2:1, less than 1.9:1, less than 1.8:1, less than 1.7:1, less than 1.6:1, less than 1.5:1, less than 1.4:1, less than 1.3:1, less than 1.2:1, less than 1.1:1, or less than 1:1.

[0045] In one embodiment, or in combination with any other embodiment, class, or subclass of this first embodiment, the MCE has a hydroxyl substituent to propionyl substituent ratio of at least 0.4:1, at least 0.5:1, at least 0.6:1, at least 0.7:1, at least 0.8:1, at least 0.9:1, at least 1:1, at least 1.1:1, at least 1.2:1, at least 1.3:1, at least 1.4:1, at least 1.5:1, at least 1.6:1, at least 1.7:1, at least 1.8:1, at least 1.9:2, or at least 2:1. Furthermore, or alternatively, this MCE has a hydroxyl substituent to propionyl substituent ratio of less than 2:1, less than 1.9:1, less than 1.8:1, less than 1.7:1, less than 1.6:1, less than 1.5:1, less than 1.4:1, less than 1.3:1, less than 1.2:1, less than 1.1:1, or less than 1:1.

[0046] In one embodiment, or in combination with any other embodiment, class, or subclass of this first embodiment, the MCE exhibits at least 40% biodegradability, at least 45% biodegradability, or at least 50% biodegradability, or at least 55% biodegradability, at least 60% biodegradability, or at least 65% biodegradability, or at least 70% biodegradability, or at least 75% biodegradability, or at least 80% biodegradability, or at least 85% biodegradability, according to at least one of the OECD 301B, OECD 301C, OECD 301D, OECD 301F, OECD TG 310, OECD TG 306, ISO 14852, or ISO 14851 test methods, after 60 days.

[0047] In one embodiment, or in combination with any other embodiment, class, or subclass of this first embodiment, the MCE exhibits at least 40% biodegradability, at least 45% biodegradability, or at least 50% biodegradability, or at least 55% biodegradability, at least 60% biodegradability, or at least 65% biodegradability, or at least 70% biodegradability, or at least 75% biodegradability, or at least 80% biodegradability, or at least 85% biodegradability, according to at least one of the OECD 301B, OECD 301C, OECD 301D, OECD 301F, OECD TG 310, OECD TG 306, ISO 14852, or ISO 14851 test methods, after 60 days.

[0048] In one embodiment, or in combination with any other embodiment, class, or subclass of this first embodiment, the MCE has a weight-average molecular weight in the range of 5,000 to 100,000 Da, or 5,000 to 50,000 Da, or 5,000 to 25,000 Da, 15,000 to 100,000 Da, or 15,000 to 50,000 Da, or 15,000 to 25,000 Da, or 50,000 to 100,000 Da, or 75,000 to 100,000 Da, or 15,000 to 250,000 Da.

[0049] In a second embodiment, this application provides a mixed cellulose ester ("MCE") having: (1) a plurality of acetyl substituents; (2) a plurality of propionyl substituents; and (3) a plurality of hydroxyl substituents, wherein the average degree of substitution of the acetyl substituents of the MCE is "DS Ac The average degree of substitution (DS) for the propionyl substituents of MCE is 0.1 to 1.2. Pr The ) is 0.1 to 1.4, and the average degree of substitution of the hydroxyl substituents on the MCE ("DS OH We disclose a mixed cellulose ester ("MCE") having a ratio of 0.7 to 2.8.

[0050] In one embodiment, or in combination with any other embodiment, class, or subclass of this second embodiment, DS Ac is at least 0.1, at least 0.2, at least 0.3, at least 0.4, at least 0.5, at least 0.6, at least 0.7, at least 0.8, at least 0.9, at least 1.0, at least 1.1, at least 1.2, at least 1.3, at least 1.4, at least 1.5, at least 1.6, at least 1.7, at least 1.8, at least 1.9, or at least 2.0. Additionally or alternatively, DS Ac This is less than 2.3, less than 2.2, less than 2.1, less than 2.0, less than 1.9, less than 1.8, less than 1.7, less than 1.6, less than 1.5, less than 1.4, less than 1.3, less than 1.2, less than 1.1, less than 1.0, less than 0.9, less than 0.8, less than 0.7, less than 0.5, less than 0.4, or less than 0.3.

[0051] In one embodiment, or in combination with any other embodiment, class, or subclass of this second embodiment, DS Ac These are 0.6-0.7, or 0.6-0.8, or 0.6-0.9, or 0.6-1.0, or 0.6-1.1, or 0.7-0.9, or 0.7-1.0, or 0.7-1.1, or 0.7-1.2, or 0.8-0.9, or 0.8-1.0, or 0.8-1.1, or 0.8-1.2, or 0.9-1.0, or 0.9-1.1, or 0.9-1.2, or 1.0-1.1, or 1.0-1.2, or 1.1-1.2.

[0052] In one embodiment, or in combination with any other embodiment, class, or subclass of this second embodiment, DS Pr is at least 0.1, at least 0.2, at least 0.3, at least 0.4, at least 0.5, at least 0.6, at least 0.7, at least 0.8, at least 0.9, at least 1.0, at least 1.1, at least 1.2, at least 1.3, or at least 1.4. Additionally or alternatively, DS PrThis is less than 1.5, less than 1.4, less than 1.3, less than 1.2, less than 1.1, less than 1.0, less than 0.9, less than 0.8, less than 0.7, less than 0.5, less than 0.4, or less than 0.3.

[0053] In one embodiment, or in combination with any other embodiment, class, or subclass of this second embodiment, DS Pr This includes 1.05-1.35, or 1.05-1.3, or 1.05-1.25, or 1.05-1.2, or 1.05-1.15, or 1.05-1.1, or 1.1-1.4, or 1.1-1.35, or 1.1-1.3, or 1.1-1.25, or 1.1-1.2, or 1.1-1.15, or 1.15-1.4, and The values ​​are 1.15-1.35, or 1.15-1.3, or 1.15-1.25, or 1.15-1.2, or 1.2-1.4, or 1.2-1.35, or 1.2-1.3, or 1.2-1.25, or 1.25-1.4, or 1.25-1.35, or 1.25-1.3, or 1.3-1.4, or 1.3-1.35.

[0054] In one embodiment, or in combination with any other embodiment, class, or subclass of this second embodiment, DS OH is at least 0.6, at least 0.7, at least 0.8, at least 0.9, at least 1.0, at least 1.1, at least 1.2, at least 1.3, at least 1.4, at least 1.5, at least 1.6, at least 1.7, at least 1.8, at least 1.9, at least 2.0, at least 2.1, at least 2.2, at least 2.3, at least 2.4, at least 2.5, or at least 2.6. Additionally or alternatively, DS OH This is less than 2.8, less than 2.7, less than 2.6, less than 2.5, less than 2.4, less than 2.3, less than 2.2, less than 2.1, less than 2.0, less than 1.9, less than 1.8, less than 1.7, less than 1.6, less than 1.5, less than 1.4, less than 1.3, less than 1.2, less than 1.1, less than 1.0, less than 0.9, or less than 0.8.

[0055] In one embodiment, or in combination with any other embodiment, class, or subclass of this second embodiment, DS OH This refers to 0.7~1.35, or 0.7~1.3, or 0.7~1.25, or 0.7~1.2, or 0.7~1.15, or 0.7~1.1, or 0.7~1.05, or 0.7~1.0, or 0.7~0.95, or 0.7~0.9, or 0.7~0.85, or 0.7~0.8, or 0.7~0.75, or 0.75~1.4, or 0.75~1.35, or 0.75~1.3, or 0.75~1.25, or 0.75~1.2, or 0.75~1.15, or 0.75~1.1, or 0.75~1.05, or 0.75~1.0, or 0.75~0.95, or 0.8 ~1.4, or 0.8~1.35, or 0.8~1.3, or 0.8~1.25, or 0.8~1.2, or 0.8~1.15, or 0.8~1.1, or 0.8~1.05, or 0.85~1.4, or 0.85~1.35, or 0.85~1.3, or 0.85~1.25, or 0.85~1.2, or 0.85~1.15, or 0.85~1.1, or 0.85~1.05, or 0.9~1.4, or 0.9~1.35, or 0.9~1.3, or 0.9~1.25, or 0.9~1.2, or 0.9~1.15, or 0.9~1.1, or 0.9~1.05.

[0056] In one embodiment, or in combination with any other embodiment, class, or subclass of this second embodiment, the mixed cellulose ester has a hydroxyl substituent to acetyl substituent ratio of at least 0.4:1, at least 0.5:1, at least 0.6:1, at least 0.7:1, at least 0.8:1, at least 0.9:1, at least 1:1, at least 1.1:1, at least 1.2:1, at least 1.3:1, at least 1.4:1, at least 1.5:1, at least 1.6:1, at least 1.7:1, at least 1.8:1, at least 1.9:2, or at least 2:1. Alternatively, this mixed cellulose ester may have a hydroxyl substituent to acetyl substituent ratio of less than 2:1, less than 1.9:1, less than 1.8:1, less than 1.7:1, less than 1.6:1, less than 1.5:1, less than 1.4:1, less than 1.3:1, less than 1.2:1, less than 1.1:1, or less than 1:1.

[0057] In one embodiment, or in combination with any other embodiment, class, or subclass of this second embodiment, the MCE has a hydroxyl substituent to propionyl substituent ratio of at least 0.4:1, at least 0.5:1, at least 0.6:1, at least 0.7:1, at least 0.8:1, at least 0.9:1, at least 1:1, at least 1.1:1, at least 1.2:1, at least 1.3:1, at least 1.4:1, at least 1.5:1, at least 1.6:1, at least 1.7:1, at least 1.8:1, at least 1.9:2, or at least 2:1. Furthermore, or alternatively, this MCE has a hydroxyl substituent to propionyl substituent ratio of less than 2:1, less than 1.9:1, less than 1.8:1, less than 1.7:1, less than 1.6:1, less than 1.5:1, less than 1.4:1, less than 1.3:1, less than 1.2:1, less than 1.1:1, or less than 1:1.

[0058] In one embodiment, or in combination with any other embodiment, class, or subclass of this second embodiment, DS Pr and DS AcThe sum of these is 1.65~2.3, or 1.65~2.2, or 1.65~2.1, or 1.65~2.0, or 1.65~1.9, or 1.65~1.8, or 1.7~2.3, or 1.7~2.2, or 1.7~2.1, or 1.7~2.0, or 1.7~1.9, or 1.7~1.8, or 1.75~2.3, or 1.75~2.2, or The ranges are 1.75-2.1, or 1.75-2.0, or 1.75-1.9, or 1.8-2.3, or 1.8-2.2, or 1.8-2.1, or 1.8-2.0, or 1.8-1.9, or 1.9-2.3, or 1.9-2.2, or 1.9-2.1, or 1.9-2.0, or 2.0-2.3, or 2.0-2.2, or 2.0-2.1.

[0059] In one embodiment, or in combination with any other embodiment, class, or subclass of this second embodiment, DS OHThese ranges from 0.6 to 0.7, or 0.7 to 1.35, or 0.7 to 1.3, or 0.7 to 1.25, or 0.7 to 1.2, or 0.7 to 1.15, or 0.7 to 1.1, or 0.7 to 1.05, or 0.7 to 1.0, or 0.7 to 0.95, or 0.7 to 0.9, or 0.7 to 0.85, or 0.7 to 0.8, or 0.7 to 0.75, or 0.75 to 1.4, or 0.75 to 1.35, or 0.75 to 1.3, or 0.75 to 1.25, or 0.75 to 1.2, or 0.75 to 1.15, or 0.75 to 1.1, or 0.75 to 1.05, or 0.75 to 1.0, or 0.75 to 0.95, or 0.8~1.4, or 0.8~1.35, or 0.8~1.3, or 0.8~1.25, or 0.8~1.2, or 0.8~1.15, or 0.8~1.1, or 0.8~1.05, or 0.85~1.4, or 0.85~1.35, or 0.85~1.3, or 0.85~1.25, or 0.85~1.2, or 0.85~1.15, or 0.85~1.1, or 0.85~1.05, or 0.9~1.4, or 0.9~1.35, or 0.9~1.3, or 0.9~1.25, or 0.9~1.2, or 0.9~1.15, or 0.9~1.1, or 0.9~1.05.

[0060] In one embodiment, or in combination with any other embodiment, class, or subclass of this second embodiment, the MCE exhibits at least 40% biodegradability, at least 45% biodegradability, or at least 50% biodegradability, or at least 55% biodegradability, at least 60% biodegradability, or at least 65% biodegradability, or at least 70% biodegradability, or at least 75% biodegradability, or at least 80% biodegradability, or at least 85% biodegradability after 60 days, according to at least one of the OECD 301B, OECD 301C, OECD 301D, OECD 301F, OECD TG 310, OECD TG 306, ISO 14852, or ISO 14851 test methods.

[0061] In one embodiment, or in combination with any other embodiment, class, or subclass of this second embodiment, the MCE exhibits at least 40% biodegradability, at least 45% biodegradability, or at least 50% biodegradability, or at least 55% biodegradability, at least 60% biodegradability, or at least 65% biodegradability, or at least 70% biodegradability, or at least 75% biodegradability, or at least 80% biodegradability, or at least 85% biodegradability after 60 days, according to at least one of the OECD 301B, OECD 301C, OECD 301D, OECD 301F, OECD TG 310, OECD TG 306, ISO 14852, or ISO 14851 test methods.

[0062] In one embodiment, or in combination with any other embodiment, class, or subclass of this second embodiment, the MCE has a weight-average molecular weight in the range of 5,000 to 100,000 Da, or 5,000 to 50,000 Da, or 5,000 to 25,000 Da, 15,000 to 100,000 Da, or 15,000 to 50,000 Da, or 15,000 to 25,000 Da, or 50,000 to 100,000 Da, or 75,000 to 100,000 Da, or 15,000 to 250,000 Da.

[0063] In a third aspect, this application also relates to a mixed cellulose ester ("MCE") having: (1) a plurality of acetyl substituents; (2) a plurality of butyryl substituents; and (3) a plurality of hydroxyl substituents, wherein the average degree of substitution of the acetyl substituents of the MCE is ("DS"). Ac The ) is 0.1 to 2.4, and the average degree of substitution (DS) for the butyryl substituents of MCE is 0.1 to 2.4. Bu The ) is 0.1 to 1.4, and the average degree of substitution of the hydroxyl substituents on the MCE ("DS OH We also disclose mixed cellulose esters ("MCE") having a ratio of 0.6 to 2.8.

[0064] In one embodiment, or in combination with any other embodiment, class, or subclass of this first embodiment, DS Ac is at least 0.1, at least 0.2, at least 0.3, at least 0.4, at least 0.5, at least 0.6, at least 0.7, at least 0.8, at least 0.9, at least 1.0, at least 1.1, at least 1.2, at least 1.3, at least 1.4, at least 1.5, at least 1.6, at least 1.7, at least 1.8, at least 1.9, or at least 2.0. Additionally or alternatively, DS Ac This is less than 2.3, less than 2.2, less than 2.1, less than 2.0, less than 1.9, less than 1.8, less than 1.7, less than 1.6, less than 1.5, less than 1.4, less than 1.3, less than 1.2, less than 1.1, less than 1.0, less than 0.9, less than 0.8, less than 0.7, less than 0.5, less than 0.4, or less than 0.3.

[0065] In one embodiment, or in combination with any other embodiment, class, or subclass of this third embodiment, DS AcThese are 0.9~2.4, 0.9~2.3, or 0.9~2.2, or 0.9~2.1, or 0.9~2.0, or 0.9~1.9, or 0.9~1.8, or 0.9~1.7, or 0.9~1.6, or 0.9~1.4, 0.9~1.3, or 0.9~1.2, or 0.9~1.1, or 0.9~1.0, or 0.92~2.4, 0.92~2.3, or 0.92~2.2, or 0.92~2.1, or 0.92~2.0, or 0.92~1.9, or 0.92~1.8, or 0.92~1.7, or 0.92~ 1.6, or 0.92~1.4, 0.92~1.3, or 0.92~1.2, or 0.92~1.1, or 0.92~1.0, or 0.94~2.4, 0.94~2.3, or 0.94~2.2, or 0.94~2.1, or 0.94~2.0, or 0.94~1.9, or 0.94~1.8, or 0.94~1.7, or 0.94~1.6, or 0.94~1.4, 0.94~1.3, or 0.94~1.2, or 0.94~1.1, or 0.94~1.0, or 0.96~2.4, 0.96~2.3, or 0 0.96~2.2, or 0.96~2.1, or 0.96~2.0, or 0.96~1.9, or 0.96~1.8, or 0.96~1.7, or 0.96~1.6, or 0.96~1.4, 0.96~1.3, or 0.96~1.2, or 0.96~1.1, or 0.96~1.0, or 0.98~2.4, 0.98~2.3, or 0.98~2.2, or 0.98~2.1, or 0.98~2.0, or 0.98~1.9, or 0.98~1.8, or 0.98~1.7, or 0.98~1.6, 0.98~1. 4. 0.98~1.3, or 0.98~1.2, or 0.98~1.1, or 0.98~1.0, or 1.0~2.4, 1.0~2.3, or 1.0~2.2, or 1.0~2.1, or 1.0~2.0, or 1.0~1.9, or 1.0~1.8, or 1.0~1.7, or 1.0~1.6, or 1.0~1.4, or 1.0~1.3, 1.0~1.2, or 1.0~1.1, or 1.1~2.4, or 1.1~2.3, or 1.1~2.2, or 1.1~2.1, or 1.1~2.0, or 1.1~1.9, or 1.1~1.8, or 1.1~1.7, or 1.1~1.6, 1.1~1.4, or 1.1~1.3, or 1.1~1.2, or 1.2~2.4, or 1.2~2.3, or 1.2~2.2, or 1.2~2.1, or 1.2~2.0, or 1.2~1.9, or 1.2~1.8, or 1.2~1.7, or 1.2~1.6, or 1.2~1.4, or 1.2~1.3, or 1.3~2.4, or 1.3~2.3, or 1.3~2.2, or 1.3~2.1, or 1.3~2.0, or 1.3~1.9, or 1.3~1.8, or 1.3~1.7, or 1.3~1.6, or 1.3~1.4, or 1.4~2.4, or 1.4~2.3, or 1.4~2.2, or 1.4~2.1, or 1.4~2.0, or 1.4~1.9, or 1.4~1.8, or 1.4~1.7, or 1.4~1.6, or 1.5~2.4, or 1.5~2.3, also 1.5~2.2, or 1.5~2.1, or 1.5~2.0, or 1.5~1.9, or 1.5~1.8, or 1.5~1.7, or 1.5~1.6, or 1.6~2.4, or 1.6~2.3, or 1.6~2.2, or 1.6~2.1, or 1.6~2.0, or 1.6~1.9, or 1.6~1.8, or 1.6~1.7, or 1.7~2.4, or 1.7~2.3, or 1.7~2.2, or 1.7~2.1, also The ranges are 1.7-2.0, or 1.7-1.9, or 1.7-1.8, or 1.8-2.3, or 1.8-2.1, or 1.8-2.0, or 1.8-1.9, or 1.9-2.3, or 1.9-2.2, or 1.9-2.1, or 1.9-2.0, or 2.0-2.4, or 2.0-2.3, or 2.0-2.2, or 2.0-2.1, or 2.1-2.4, or 2.1-2.3, or 2.1-2.2, or 2.2-2.3.

[0066] In one embodiment, or in combination with any other embodiment, class, or subclass of this third embodiment, DS Buis at least 0.1, at least 0.2, at least 0.3, at least 0.4, at least 0.5, at least 0.6, at least 0.7, at least 0.8, at least 0.9, at least 1.0, at least 1.1, at least 1.2, at least 1.3, or at least 1.4. Additionally or alternatively, DS Bu This is less than 1.5, less than 1.4, less than 1.3, less than 1.2, less than 1.1, less than 1.0, less than 0.9, less than 0.8, less than 0.7, less than 0.5, less than 0.4, or less than 0.3.

[0067] In one embodiment, or in combination with any other embodiment, class, or subclass of this third embodiment, DS BuThis includes 0.1~1.35, or 0.1~1.3, or 0.1~1.25, or 0.1~1.2, or 0.1~1.15, or 0.1~1.1, or 0.1~1.0, or 0.1~0.8, or 0.1~0.6, or 0.2~1.35, or 0.2~1.3, or 0.2~1.25, or 0.2~1.2, or 0.2~1.15, or 0.2~1.1, or 0.2~1.0, or 0.2~0.8, or 0.2~0.6, or 0.2~0.4, or 0.3~1.35, or 0.3~1.3, or 0.3~1.25, or 0.3~1.2, or 0.3~1.15, or 0.3~1.1, or 0.3~1.0, or 0.3~0.8, or 0.3~0.6, or 0.3~0.5, or 0.4~1.35, or 0.4~1.3, or 0.4~1.25, or 0.4~1.2, or 0.4~1.15, or 0.4~1.1, or 0.4~1.0, or 0.4~0.8, or 0.4~0.6, or 0.5~1.35, or 0.5~1.3, or 0.5~1.25, or 0.5~1.2, or 0.5~1.15, or 0.5~1.1, also 0.5~1.0, or 0.5~0.8, or 0.5~0.7, or 0.6~1.35, or 0.6~1.3, or 0.6~1.25, or 0.6~1.2, or 0.6~1.15, or 0.6~1.1, or 0.6~1.0, or 0.6~0.8, or 0.7~1.35, or 0.7~1.3, or 0.7~1.25, or 0.7~1.2, or 0.7~1.15, or 0.7~1.1, or 0.7~1.0, or 0.8~1.35, or 0.8~1.3, or 0.8~1.25, or 0.8~1.2, also 0.8~1.15, or 0.8~1.1, or 0.8~1.0, or 0.9~1.35, or 0.9~1.3, or 0.9~1.25, or 0.9~1.2, or 0.9~1.15, or 0.9~1.1, or 1.0~1.35, or 1.0~1.3, or 1.0~1.25, or 1.0~1.2, or 1.0~1.15, or 1.0~1.1, or 1.05~1.35, or 1.05~1.3, or 1.05~1.25, or 1.05~1.2, or 1.05~1.15, or 1.05~1.1, or 1.The ranges are 1-1.4, or 1.1-1.35, or 1.1-1.3, or 1.1-1.25, or 1.1-1.2, or 1.1-1.15, or 1.15-1.4, or 1.15-1.35, or 1.15-1.3, or 1.15-1.25, or 1.15-1.2, or 1.2-1.4, or 1.2-1.35, or 1.2-1.3, or 1.2-1.25, or 1.25-1.4, or 1.25-1.35, or 1.25-1.3, or 1.3-1.4, or 1.3-1.35.

[0068] In one embodiment, or in combination with any other embodiment, class, or subclass of this third embodiment, DS OH is at least 0.6, at least 0.7, at least 0.8, at least 0.9, at least 1.0, at least 1.1, at least 1.2, at least 1.3, at least 1.4, at least 1.5, at least 1.6, at least 1.7, at least 1.8, at least 1.9, at least 2.0, at least 2.1, at least 2.2, at least 2.3, at least 2.4, at least 2.5, or at least 2.6. Additionally or alternatively, DS OH This is less than 2.8, less than 2.7, less than 2.6, less than 2.5, less than 2.4, less than 2.3, less than 2.2, less than 2.1, less than 2.0, less than 1.9, less than 1.8, less than 1.7, less than 1.6, less than 1.5, less than 1.4, less than 1.3, less than 1.2, less than 1.1, less than 1.0, less than 0.9, or less than 0.8.

[0069] In one embodiment, or in combination with any other embodiment, class, or subclass of this third embodiment, DS OHThis is 0.5~1.0, or 0.5~0.95, or 0.5~0.9, or 0.5~0.85, or 0.5~0.8, or 0.5~0.75, or 0.5~0.7, or 0.5~0.65, or 0.5~0.6, or 0.5~0.55, or 0.55~1.0, or 0.55~0.95, or 0.55~0.9, or 0.55~0.85, or 0.55~0.8, or 0.55~0.75, or 0.55~0.7, or 0 It is 0.55 or 0.65, or 0.55-0.6, or 0.6-0.65, or 0.6-0.7, or 0.6-0.75, or 0.6-0.8, or 0.6-0.85, or 0.6-0.9, or 0.6-0.95, or 0.6-1.0, or 0.65-0.7, or 0.65-0.75, or 0.65-0.8, or 0.65-0.85, or 0.65-0.9, or 0.65-0.95, or 0.65-1.0.

[0070] In one embodiment, or in combination with any other embodiment, class, or subclass of this third embodiment, DS Bu and DS Ac The sum of these is 1.65~2.3, or 1.65~2.2, or 1.65~2.1, or 1.65~2.0, or 1.65~1.9, or 1.65~1.8, or 1.7~2.3, or 1.7~2.2, or 1.7~2.1, or 1.7~2.0, or 1.7~1.9, or 1.7~1.8, or 1.75~2.3, or 1.75~2.2, or The ranges are 1.75-2.1, or 1.75-2.0, or 1.75-1.9, or 1.8-2.3, or 1.8-2.2, or 1.8-2.1, or 1.8-2.0, or 1.8-1.9, or 1.9-2.3, or 1.9-2.2, or 1.9-2.1, or 1.9-2.0, or 2.0-2.3, or 2.0-2.2, or 2.0-2.1.

[0071] In one embodiment, or in combination with any other embodiment, class, or subclass of this third embodiment, the mixed cellulose ester has a hydroxyl substituent to acetyl substituent ratio of at least 0.4:1, at least 0.5:1, at least 0.6:1, at least 0.7:1, at least 0.8:1, at least 0.9:1, at least 1:1, at least 1.1:1, at least 1.2:1, at least 1.3:1, at least 1.4:1, at least 1.5:1, at least 1.6:1, at least 1.7:1, at least 1.8:1, at least 1.9:2, or at least 2:1. Alternatively, this mixed cellulose ester may have a hydroxyl substituent to acetyl substituent ratio of less than 2:1, less than 1.9:1, less than 1.8:1, less than 1.7:1, less than 1.6:1, less than 1.5:1, less than 1.4:1, less than 1.3:1, less than 1.2:1, less than 1.1:1, or less than 1:1.

[0072] In one embodiment, or in combination with any other embodiment, class, or subclass of this third embodiment, the mixed cellulose ester has a hydroxyl substituent to butyryl substituent ratio of at least 0.4:1, at least 0.5:1, at least 0.6:1, at least 0.7:1, at least 0.8:1, at least 0.9:1, at least 1:1, at least 1.1:1, at least 1.2:1, at least 1.3:1, at least 1.4:1, at least 1.5:1, at least 1.6:1, at least 1.7:1, at least 1.8:1, at least 1.9:2, or at least 2:1. Furthermore, or alternatively, this mixed cellulose ester has a hydroxyl substituent to butyryl substituent ratio of less than 2:1, less than 1.9:1, less than 1.8:1, less than 1.7:1, less than 1.6:1, less than 1.5:1, less than 1.4:1, less than 1.3:1, less than 1.2:1, less than 1.1:1, or less than 1:1.

[0073] In one embodiment, or in combination with any other embodiment, class, or subclass of this third embodiment, the MCE exhibits at least 40% biodegradability, at least 45% biodegradability, or at least 50% biodegradability, or at least 55% biodegradability, at least 60% biodegradability, or at least 65% biodegradability, or at least 70% biodegradability, or at least 75% biodegradability, or at least 80% biodegradability, or at least 85% biodegradability, according to at least one of the OECD 301B, OECD 301C, OECD 301D, OECD 301F, OECD TG 310, OECD TG 306, ISO 14852, or ISO 14851 test methods, after 60 days.

[0074] In one embodiment, or in combination with any other embodiment, class, or subclass of this third embodiment, the MCE has a weight-average molecular weight in the range of 5,000 to 100,000 Da, or 5,000 to 50,000 Da, or 5,000 to 25,000 Da, or 15,000 to 100,000 Da, or 15,000 to 50,000 Da, or 15,000 to 25,000 Da, or 50,000 to 100,000 Da, or 75,000 to 100,000 Da, or 15,000 to 250,000 Da.

[0075] In combination with one embodiment or any embodiment referenced herein, the CE to be ground to produce CE fine particles 112 may be a mixed cellulose ester of the first, second, and / or third embodiment (including any class or subclass of these embodiments).

[0076] system Referring now to Figure 2, a dry grinding system 132 for generating CE fine particles 112 (shown in Figure 1) is illustrated. In one embodiment, the dry grinding system in Figure 2 is used as the dry grinding unit 114 in Figure 1. In the embodiment shown in Figure 2, the CE particles 134 are fed to a jet mill 136 by a feed system to generate CE fine particles 112 having a desired average particle size. This feed system may include a source of CE particles 138, a feeder 140 and / or a nozzle 142.

[0077] In one embodiment, or in combination with any embodiment referenced herein, the CE particle source 138 comprises a CE generating facility 108 (shown in Figure 1) as described above. Additionally or alternatively, the CE particle source 138 may be a package such as a supersack containing ready-made CE particles 134 received from a CE manufacturer.

[0078] The CE particles 134 released from the supply source 138 are received by the feeder 140, which is used to control the feed rate of the initial CE particles 134 supplied to the jet mill 136. By supplying the CE particles 134 to the jet mill 136 at a controlled and substantially stable feed rate, it is possible to reduce the CE particles 134 to a desired average particle size. In one embodiment, or in combination with any embodiment referenced herein, the feeder 140 is a weight reduction feeder.

[0079] The CE particles 134 discharged from the feeder 140 are received in the nozzle 142 before being supplied to the jet mill 136. The CE particles 134 are mixed with a portion of the compressed gas 144 (e.g., compressed air) in the nozzle 142, as will be described in more detail below, to form the particle feed stream 146. Combining the CE particles 134 with the compressed gas 144 facilitates the efficient and controllable delivery of the CE particles 134 to the jet mill 136. In one embodiment, or in combination with any embodiment referred to herein, the nozzle 142 is a Venturi nozzle. Thus, the pressure difference formed within the nozzle 142 by the compressed gas 144 is used to draw the CE particles 134 from the feeder 140 into the nozzle 142, thereby forming the particle feed stream 146.

[0080] System 132 also includes a compressor 148 for generating compressed gas 144. Compressed gas 144 can be generated by the compressor 148 from ambient air and / or a separated gas stream 150, as will be described in more detail below. If the amount of separated / recirculated gas stream 150 is insufficient, a fresh gas stream 151 (e.g., air) can be supplied to the compressor 148. In one embodiment, or in combination with any embodiment referred to herein, the compressed gas 144 released from the compressor 148 is provided for use in at least one of the jet mills 136, or for use when transporting CE particles 134 to the jet mill 136.

[0081] For example, system 132 includes a splitter 152 downstream of the compressor 148 for splitting the compressed gas 144 into a first portion 154 and a second portion 156. As described above, the first portion 154 is supplied to the jet mill 136, and the second portion 156 is supplied to the nozzle 142 of the feed system.

[0082] In the illustrated embodiment, a pressure regulator 158 is positioned between the splitter 152 and the jet mill 136. The pressure regulator 158 regulates the pressure and / or velocity of a first portion 154 of compressed gas 144 to produce grinding gas 160 supplied to the jet mill 136. This pressure regulation may be based on a desired particle size distribution of CE particulate matter 112 produced from CE particles 134 by the jet mill 136. In one embodiment, or in combination with any embodiment referred to herein, the grinding gas 160 (i.e., the regulated first portion 154) is supplied to the jet mill 136 at a faster velocity than the second portion 156 supplied to the nozzle 142.

[0083] In an alternative embodiment, the nozzle 142 is positioned between the pressure regulator 158 and the jet mill 136. The grinding gas 160 is supplied directly to the nozzle 142 to deliver the particle flow 146 into the jet mill. In this setup, there is no second portion 156 supplying the nozzle 142.

[0084] In one embodiment or in combination with any embodiment referred to herein, the jet mill 136 is a high-speed fluid energy impact mill that circulates CE particles 134 accompanied by a grinding gas 160 therein. The jet mill 136 generally does not contain any moving parts. Thus, the CE particles 134 are reduced by facilitating collisions between individual particles and / or between particles and parts of the jet mill 136 itself.

[0085] As described above, the particle size distribution of the resulting CE particles 112 generated in the jet mill 136 is controlled based on the pressure and / or velocity of the grinding gas 160 supplied to the jet mill 136. In one embodiment, or in combination with any embodiment referenced herein, the grinding performed in the jet mill 136 reduces the D50 particle size of the initial CE particles 134 by at least 25, 50, 75, 85, 90, or 95 percent.

[0086] The pulverized CE stream 164, containing CE particles 112 encompassed in the pulverizing gas 160, is supplied from the jet mill 136 to the separator 166. The separator 166 separates the CE particles 112 from the pulverizing gas 160, thereby forming the CE particle stream 168 and the separated gas stream 150. In one embodiment or in combination with any embodiment referenced herein, the separation is performed by filtering the CE particles 112 from the pulverizing gas 160.

[0087] For example, referring to Figure 4, the separator 166 comprises a housing 170 and a filter 172 located within it. The housing 170 receives the pulverized CE flow 164, and the filter 172 separates the CE particles 112 from the pulverized gas 160. Thus, the CE particles 112 and the separated gas flow 150 (formed from the pulverized gas 160) are discharged from the housing 170 in separate flows. Furthermore, pulsed gas 174 can be supplied to the housing 170 to remove any particles collected by the filter 172.

[0088] Referring again to Figure 2, the separated gas stream 150 can be recycled / recirculated, as described above, for use in at least one of the jet mills 136, or when transporting initial CE particles to the jet mill 136 via the nozzle 142. In one embodiment, or in combination with any embodiment referred to herein, recycling is performed by compressing the separated gas stream 150 in a compressor 148, thereby generating compressed gas 144.

[0089] The particulate CE product stream 168 may be sent to at least one product packaging station 176 to collect the CE particles 112. Referring to Figure 2, the particulate CE product stream 168 is sent to a single product packaging station 176 to collect all the CE particles 112 contained therein, regardless of their relative particle size.

[0090] Referring to Figure 3, the CE particles are collected in separate product packaging stations, for example, a first product packaging station 178 and a second product packaging station 180. In one embodiment, or in combination with any embodiment referenced herein, rotational circulation of the CE particles 134 in the jet mill 136 can generate CE particle fractions of different sizes in different radial regions within the jet mill 136.

[0091] In one embodiment, or in combination with any embodiment referenced herein, a first product packaging station 178 is for collecting a crude product fraction 182 of CE fine particles, and a second product packaging station 180 is for collecting a fine product fraction 184 of CE fine particles. In the illustrated embodiment, the first product packaging station 178 receives the crude product fraction 182 directly from the jet mill 136. The second product packaging station 180 receives the fine product fraction 184 indirectly from the jet mill 136. That is, a separator 166 is positioned between the jet mill 136 and the second product packaging station 180.

[0092] Initial CE particles As described above, the initial CE particles used to generate CE fine particles may originate from a CE generation facility as shown in Figure 1, and / or be received in bulk packages from a CE manufacturer.

[0093] In one embodiment, or in combination with any embodiment referenced herein, the initial CE particles have an average particle size of at least 75 microns.

[0094] In one embodiment, or in combination with any embodiment referenced herein, the initial CE particles are in the form of at least one of powder, flake, or pellet.

[0095] In one embodiment, or in combination with any embodiment referenced herein, the initial CE particles are in the form of a powder having an average particle size of at least 50, 75, 100, 150, 200, 250, 300, 350, or 400 microns and / or 1500, 1250, 1000, 900, 800, 700, 600, or 500 microns or less.

[0096] In one embodiment, or in combination with any embodiment referenced herein, the initial CE particles are in the form of flakes having an average particle size of at least 500, 1000, 2000, 3000, 4000, or 5000 microns and / or 10000, 8000, 6000, 4000, or 2000 microns or less.

[0097] In one embodiment, or in combination with any embodiment referenced herein, the initial CE particles are in the form of pellets having an average particle size of at least 500, 1000, 1500, 2000, 2500, or 3000 microns and / or 20000, 15000, 10000, 8000, 6000, 5000, 4000, or 3000 microns or less.

[0098] The average particle size of the initial CE particles (e.g., powder, flakes, or pellets) is determined by measuring the maximum external dimensions of 30 randomly selected representative particles and calculating the average of those 30 maximum external dimensions. The measurement of the maximum external dimensions is performed by capturing two-dimensional images of at least 30 representative particles in which the maximum external dimensions are clearly visible. The maximum external dimensions of the 30 particles in the two-dimensional images are measured electronically or manually using a caliper-type measuring technique.

[0099] In one embodiment, or in combination with any embodiment referenced herein, the initial CE particles contain CE in an amount of at least 50, 60, 70, 80, 90, 95, or 99 percent by weight.

[0100] In one embodiment, or in combination with any embodiment referenced herein, the initial CE particles have a water content in the range of 0.5–10, 0.5–8.0, 0.5–6.0, or 0.5–5.0 weight percent.

[0101] CE fine particles The CE particles produced by the processes disclosed herein exhibit enhanced solidity and / or tactile properties, making them desirable for use in, for example, personal care products, cosmetics, and the like.

[0102] In one embodiment, or in combination with any embodiment referenced herein, the CE particles are 0.5-100, 1-100, 1-80, 1-70, 1-60, 1-50, 1-40, 1-35, 1-30, 1-25, 1-20, 1-15, 1-10, 2-100, 2-80, 2-70, 2-60, 2-50, 2-40, 2-35 2-30, 2-25, 2-20, 2-15, 2-10, 3-100, 3-80, 3-70, 3-60, 3-50, 3-40, 3-35, 3-30, 3-25, 3-20, 3-15, 3-10, 5-100, 5-80, 5-70, 5-60, 5-50, 5-40, 5-35, 5-30, 5-25, 5-20, 5-15, 5-10 10-100, 10-80, 10-70, 10-60, 10-50, 10-40, 10-35, 10-30, 10-25, 10-20, 10-15, 15-100, 15-80, 15-70, 15-60, 15-50, 15-40, 15-35, 15-30, 15-25, 15-20, 20-100, 20-80, 20-70 It has a D50 particle size in the range of 20-60, 20-50, 20-40, 20-35, 20-30, 25-100, 25-80, 25-70, 25-60, 25-50, 25-40, 25-35, 25-30, 30-100, 30-80, 30-70, 30-60, 30-50, 30-40, or 30-35 microns. For example, the cured CE fine particles may have a D50 particle size of 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, or 100 microns.

[0103] As used herein, the term "D50" means that 50% of the particulate matter has a maximum dimension of less than or equal to the stated value (e.g., 10 microns) on a volume basis. The D50 value may also be treated as the median particle size. To ensure that a representative D50 value is obtained, the sample size of the particulate matter must be at least 0.5 grams. The sample size of the particulate matter is then dispersed and mixed in 1.5 ounces of an aqueous solution of isopropanol or surfactant (one drop of 5% (v / v) IgePal® CO-630 surfactant). The D50 test is performed by a computer algorithm using laser diffraction and Mie theory to generate the particle size distribution. One suitable particle size analyzer for determining the D50 value is the Malvern Mastersizer 3000 from Malvern Panalytical. When using the Malvern Mastersizer, the obscuration rate may be set to 2% to 5%, and the sample measurement time should be set to 3 seconds for both red and blue light measurements. The dispersed sample is added until the desired obscuration rate (approximately 4%) is achieved, and then the measurement is performed. After the first measurement, the sample is sonicated at 50% power for 120 seconds. Subsequently, once the light energy has stabilized after sonication (usually less than 1 minute), the dispersed sample is measured again.

[0104] In one embodiment, or in combination with any embodiment referenced herein, the CE particles have a D10 particle size of 0.5-20, 0.5-15, 0.5-12, 0.5-10, 0.5-5, 0.5-4, 0.5-3, 0.5-2, 0.5-1, 1-20, 1-15, 1-12, 1-5, 1-3, 2-20, 2-10, 2-5, 3-20, 3-15, 3-10, 4-20, 4-15, 4-10, 5-20, 5-15, 5-10, 10-20, or 10-15 microns. For example, CE particles may have a D10 particle size of 0.5, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19 microns, or 20 microns.

[0105] As used herein, the term "D10" means that 10% of the particulate matter has a maximum dimension of no more than the stated value (e.g., 10 microns) on a volume basis. To ensure that a typical D10 value is obtained, the sample size of the particulate matter must be at least 0.5 grams. The sample size of the particulate matter is then dispersed and mixed in 1.5 ounces of an aqueous solution of isopropanol or surfactant (one drop of 5% (v / v) IgePal® CO-630 surfactant). The D10 test is performed by a computer algorithm using laser diffraction and Mie theory to generate the particle size distribution. One suitable particle size analyzer for determining the D10 value is the Malvern Mastersizer 3000 from Malvern Panalytical. When using the Malvern Mastersizer, the obscuration rate may be set to 2% to 5%, and the sample measurement time is set to 3 seconds for both red and blue light measurements. The dispersed sample is added until the desired obscuration rate (approximately 4%) is achieved, and then the measurement is performed. After the first measurement, the sample is sonicated at 50% power for 120 seconds. Subsequently, once the light energy stabilizes after sonication (usually less than 1 minute), the dispersed sample is measured again.

[0106] In one embodiment, or in combination with any embodiment referenced herein, the CE particles are 1-100, 1-80, 1-70, 1-60, 1-50, 1-40, 1-35, 1-30, 1-25, 1-20, 1-15, 1-10, 5-100, 5-80, 5-70, 5-60, 5-50, 5-40, 5-35, 5-30, 5-25, 5-20, 5-15, 5-10, 10-100, 10-80, 10-70, 10-60, 10-50, 10-40, 10-35, 10-30, 10-25, 10-20, 10- It has a D90 particle size in the range of 15, 15-100, 15-80, 15-70, 15-60, 15-50, 15-40, 15-35, 15-30, 15-25, 15-20, 20-100, 20-80, 20-70, 20-60, 20-50, 20-40, 20-35, 20-30, 25-100, 25-80, 25-70, 25-60, 25-50, 25-40, 25-35, 25-30, 30-100, 30-80, 30-70, 30-60, 30-50, 30-40, or 30-35 microns. For example, CE particles may have a D90 particle size of 100, 90, 80, 70, 60, 50, 49, 48, 47, 46, 45, 44, 43, 42, 41, 40, 39, 38, 37, 36, 35, 34, 33, 32, 31, 30, 29, 28, 27, 26, 25, 24, 23, 22, 21, or 20 microns.

[0107] As used herein, the term "D90" means that 90% of the particulate matter has a maximum dimension of no more than the stated value (e.g., 10 microns) on a volume basis. To ensure that a typical D90 value is obtained, the sample size of the particulate matter must be at least 0.5 grams. The sample size of the particulate matter is then dispersed and mixed in 1.5 ounces of an aqueous solution of isopropanol or surfactant (one drop of 5% (v / v) IgePal® CO-630 surfactant). The D90 test is performed by a computer algorithm using laser diffraction and Mie theory to generate the particle size distribution. One suitable particle size analyzer for determining the D90 value is the Malvern Mastersizer 3000 from Malvern Panalytical. When using the Malvern Mastersizer, the obscuration rate may be set to 2% to 5%, and the sample measurement time is set to 3 seconds for both red and blue light measurements. The dispersed sample is added until the desired obscuration rate (approximately 4%) is achieved, and then the measurement is performed. After the first measurement, the sample is sonicated at 50% power for 120 seconds. Subsequently, once the light energy stabilizes after sonication (usually less than 1 minute), the dispersed sample is measured again.

[0108] In one embodiment, or in combination with any embodiment referenced herein, the CE particles are 1-100, 1-80, 1-70, 1-60, 1-50, 1-40, 1-35, 1-30, 1-25, 1-20, 1-15, 1-10, 5-100, 5-80, 5-70, 5-60, 5-50, 5-40, 5-35, 5-30, 5-25, 5-20, 5-15, 5-10, 10-100, 10-80, 10-70, 10-60, 10-50, 10-40, 10-35, 10-30, 10-25, 10-20, 10-1 5, has a D100 particle size in the range of 15-100, 15-80, 15-70, 15-60, 15-50, 15-40, 15-35, 15-30, 15-25, 15-20, 20-100, 20-80, 20-70, 20-60, 20-50, 20-40, 20-35, 20-30, 25-100, 25-80, 25-70, 25-60, 25-50, 25-40, 25-35, 25-30, 30-100, 30-80, 30-70, 30-60, 30-50, 30-40, or 30-35 microns. For example, CE particles may have a D100 particle size of 100, 90, 80, 70, 60, 50, 49, 48, 47, 46, 45, 44, 43, 42, 41, 40, 39, 38, 37, 36, 35, 34, 33, 32, 31, 30, 29, 28, 27, 26, 25, 24, 23, 22, 21, or 20 microns.

[0109] As used herein, the term "D100" means that 100% of the particulate matter has a maximum dimension of no more than the stated value (e.g., 10 microns) on a volume basis. To ensure that a typical D100 value is obtained, the sample size of the particulate matter must be at least 0.5 grams. The sample size of the particulate matter is then dispersed and mixed in 1.5 ounces of an aqueous solution of isopropanol or surfactant (one drop of 5% (v / v) IgePal® CO-630 surfactant). The D100 test is performed by a computer algorithm using laser diffraction and Mie theory to generate the particle size distribution. One suitable particle size analyzer for determining the D100 value is the Malvern Mastersizer 3000 from Malvern Panalytical. When using the Malvern Mastersizer, the obscuration rate may be set to 2% to 5%, and the sample measurement time is set to 3 seconds for both red and blue light measurements. The dispersed sample is added until the desired obscuration rate (approximately 4%) is achieved, and then the measurement is performed. After the first measurement, the sample is sonicated at 50% power for 120 seconds. Subsequently, once the light energy stabilizes after sonication (usually less than 1 minute), the dispersed sample is measured again.

[0110] In one embodiment, or in combination with any embodiment referenced herein, CE particles exhibit at least 50, 55, 60, 65, 70, 75, 80, or 85 percent biodegradability in 60 days by at least one of the OECD 301B, OECD 301C, OECD 301D, OECD 301F, OECD TG 310, OECD TG 306, ISO 14852, or ISO 14851 test methods.

[0111] In one embodiment, or in combination with any embodiment referenced herein, the CE microparticles, using olive oil instead of castor oil, exhibit an oil absorption rate of at least 0.5, 0.6, 0.7, or 0.8 g / g according to ASTM D281.

[0112] The oil absorption rate was measured according to a modified version of the ASTM D281 standard test method used to measure the oil absorption of micropowder. In the modified method, a known amount of micropowder (approximately 0.20 g) was weighed into a glass vial, and olive oil was added dropwise to the micropowder using a pipette. After adding olive oil dropwise, the powder was thoroughly mixed with the oil. The test was completed when the amount of oil was incorporated into the powder, forming a very hard, putty-like paste that did not break or separate. The amount of oil added to the powder was then weighed in a drip bottle containing the oil to determine the amount of oil added to the powder.

[0113] The oil absorption capacity was calculated according to the following formula: Oil absorption (g / g) = AB / W (In the formula, A = initial weight of the oil-containing dropper bottle, B = final weight of the oil-containing dropper bottle, and W = weight of the sample in grams). The experiment was carried out under the same conditions and repeated at least two more times. The oil absorption rate was determined from the average of the experimental results.

[0114] In one embodiment, or in combination with any embodiment referenced herein, the CE particles exhibit a unimodal particle size distribution having a span of at least 0.5, 0.55, 0.6, 0.65, 0.7, 0.75, 0.8, 0.85, 0.9, 0.95, 1.0, 1.05, 1.1, 1.15, 1.2, 1.25, 1.3, or less than 1.4 and / or 3.0, 2.9, 2.8, 2.7, 2.6, 2.5, 2.4, 2.3, 2.2, 2.1, 2.0, 1.9, 1.8, 1.7, 1.6, or less than 1.5. In certain embodiments, CE particles exhibit a unimodal particle size distribution having spans of 1.0–3.0, 1.0–2.5, 1.0–2.0, 1.0–1.8, 1.0–1.6, 1.2–3.0, 1.2–2.5, 1.2–2.0, 1.2–1.8, 1.2–1.6, 1.3–3.0, 1.3–2.5, 1.3–2.0, 1.3–1.8, or 1.3–1.6. As used herein, “unimodal particle size distribution” refers to a particle size distribution of a material having only one prominent peak in its size distribution. This is in contrast to a multimodal particle size distribution, which has two or more peaks in its particle size distribution. The “span” of the unimodal peak can be measured using the following formula, with respect to the D10, D50, and D90 values ​​of the particle. (D x (90)-D x (10)) / D x (50) In the formula, "x" is the specified particle size.

[0115] In one embodiment, or in combination with any embodiment referenced herein, the CE particles have a polydispersity index of less than 0.8, 0.7, 0.6, 0.5, 0.4, or 0.3, and a degree of sphericity of less than 70, 65, 60, 55, 50, 45, 40, 35, or 30 percent.

[0116] The average sphericity is determined by (1) obtaining a secondary emission / ETD detector scanning electron microscope (SEM) image of a representative sample consisting of at least 40 microparticles; (2) selecting a square sample window centered on the SEM containing exactly 30 microparticles whose entire circumference is clearly visible (i.e., not obstructed) on this SEM image; (3) measuring the maximum and minimum diameters of the 30 clearly visible microparticles within this sample window (each extended through the center of gravity of the particle and not necessarily perpendicular to each other); (4) obtaining the sphericity of each of the 30 individual particles by dividing the minimum diameter by the maximum diameter and multiplying the result by 100%; and (5) obtaining the average sphericity by averaging the sphericities of the 30 individual particles.

[0117] In one embodiment, or in combination with any embodiment referenced herein, the CE particles have a butyric acid content of 500, 400, 300, 200, 100, 50, 20, 10, 7.5, 5, 2.5, or less than 1 ppmw.

[0118] In one embodiment, or in combination with any embodiment referenced herein, the CE fine particles have an acetic acid content of 500, 400, 300, 200, 100, 50, 20, 10, 7.5, 5, 2.5, or less than 1 ppmw.

[0119] In one embodiment, or in combination with any embodiment referenced herein, the CE particles have a propionic acid content of 500, 400, 300, 200, 100, 50, 20, 10, 7.5, 5, 2.5, or less than 1 ppmw.

[0120] The butyric acid, acetic acid, and propionic acid content of CE microparticles can be measured by gas chromatography ("GC"). In one GC method, the butyric acid, acetic acid, and propionic acid content can be measured by adding approximately 100 mg of CE microparticles to a tare-filled 4-dram vial, followed by the addition of an internal standard solution of a 90:10 dichloromethane / methanol mixture containing nonane. A magnetic stirrer is placed in the vial, and the sample is stirred for 2 hours. After stirring, 8.0 mL of n-heptane is added dropwise to precipitate the polymer, and then the sample is vortexed. Approximately 100 mg of the supernatant is transferred to a GC vial with 100 μL of pyridine and 450 μL of BSTFA. The sample is heated at 80°C for 30 minutes, and then cooled to room temperature before injection. The sample is simultaneously chromatographed using 100% dimethylpolysiloxane and 14% cyanopropyl-phenyl-methylpolysiloxane columns with temperature programming and flame ionization detection. Alternatively, the second GC methodology involves preparing the sample by adding approximately 30 mg of CE microparticles, followed by 200 μL of an internal standard solution containing decane in pyridine and 1.0 mL of BSTFA, to a tare-filled GC vial. The vial is heated at 80°C for 30 minutes and then cooled to room temperature before injection. The sample is then simultaneously chromatographed using 100% dimethylpolysiloxane and 6% cyanopropyl-phenyl-methylpolysiloxane columns with temperature programming and flame ionization detection.

[0121] In one embodiment, or in combination with any embodiment referenced herein, the CE microparticles have a sulfuric acid content of less than 500, 400, 300, 200, 100, 50, 20, 10, 7.5, 5, 2.5, or 1 ppmw. The sulfuric acid content of the CE microparticles can be measured by the following methodology: First, the test sample is added to a titration cell and dissolved in the solvent to a total volume of 70 mL. A solvent blank is also prepared for comparison. Next, the sample and the blank are titrated with 0.05 N potassium hydroxide in methanol using an automated titrator equipped with a combination glass potential measuring electrode. The acid value is calculated based on the weight of the sample and the value obtained by subtracting the KOH consumed in the blank from the KOH consumed in the sample.

[0122] In one embodiment, or in combination with any embodiment referenced herein, the CE particles have a CE content of at least 50, 55, 60, 65, 70, 75, 80, 85, 90, 91, 92, 93, 94, 95, 96, 97, 98, or 99 weight percent of the mixed cellulose ester of the first, second, and / or third embodiment (including any class or subclass of these embodiments). Furthermore, or alternatively, the CE particles may have a CE content of less than 99.9, 99.5, 99, 98, 97, 96, 95, 94, 93, 92, 91, 90, 89, 88, 87, 86, or 85 weight percent of the mixed cellulose ester of the first, second, and / or third embodiment (including any class or subclass of these embodiments). In certain embodiments, the CE fine particles may essentially consist of a mixed cellulose ester of the first, second, and / or third embodiment (including any class or subclass of these embodiments).

[0123] In one embodiment, or in combination with any embodiment referenced herein, the CE fine particles may include an additional biodegradable cellulose ester different from the mixed cellulose ester of the first, second, and / or third embodiment. In such embodiments, this additional cellulose ester may be cellulose acetate exhibiting at least 40% biodegradability, at least 45% biodegradability, or at least 50% biodegradability, or at least 55% biodegradability, or at least 60% biodegradability, or at least 65% biodegradability, or at least 70% biodegradability, or at least 75% biodegradability, or at least 80% biodegradability, or at least 85% biodegradability in 60 days according to at least one of the OECD 301B, OECD 301C, OECD 301D, OECD 301F, OECD TG 310, OECD TG 306, ISO 14852, or ISO 14851 test method.

[0124] In one embodiment, or in combination with any embodiment referenced herein, the CE microparticles may contain at least 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 weight percent of additional biodegradable cellulose esters different from the mixed cellulose esters of the first, second, and / or third embodiments. Furthermore, or alternatively, the CE microparticles may contain less than 50, 45, 40, 35, 30, 25, 20, 15, 10, or 5 weight percent of additional biodegradable cellulose esters different from the mixed cellulose esters of the first, second, and / or third embodiments.

[0125] In one embodiment, or in combination with any embodiment referenced herein, CE particles, when measured by ISO9277 using Micromeritics ASAP 2020 equipment and krypton gas, have a density of at least 0.1, 0.5, 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9, 3.0, 3.1, 3.2, 3.3, 3.4, 3.5, 3.6, 3.7, 3.8, 3.9, 4.0, 4.1, 4.2, 4.3, 4.4, 4.5, 4.6, 4.7, 4.8, 4.9, 5.0, 5.1, 5.2, 5.3, 5.4, 5.5, 5.6, 5.7, 5.8, 5.9, 6.0, 6.1, 6.2, 6.3, 6.4, 6.5, 6.7, 6.8, 6.9, 7.0, 7.1, 7.2, 7.3, 7.4, 7.5, 7.6, 7.7, 7.8, 7.9, or 8.0m 2 / g, and / or 100, 95, 90, 85, 80, 75, 70, 65, 60, 55, 50, 45, 40, 35, 30, 29, 28, 27, 26, 25, 24, 23, 22, 21, 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2.5, 2, 1.9, 1.8, 1.7, 1.6, 1.5, 1.4, or 1.3m 2The average BET surface area is less than / g. This measurement method includes the following steps: (1) Degass 0.5 to 1 gram of sample overnight at 60°C; (2) Determine the sample mass by the weight difference between an empty sample tube and a sample tube filled with the sample after degassing; (3) Use krypton adsorption at 77K for specific surface area analysis; (4) Collect seven relative pressures from 0.06 to 0.20 and adapt them for BET specific surface area analysis. The amount of sample depends on the specific need and the amount of water contained in it.

[0126] In one embodiment, or in combination with any embodiment referenced herein, the CE particles are 0.2-0.3 g / m² 3 It has a bulk density within the range of [value].

[0127] In one embodiment, or in combination with any embodiment referenced herein, the CE particles have an average sphericity of at least 20, 30, 40, 50, or 60 percent and / or 90, 80, 70, 60, or 50 percent or less.

[0128] In one embodiment, or in combination with any embodiment referenced herein, the CE particles have an average smoothness of at least 10, 20, 30, 40, 50, 60, 70, 80, 90, 95, 95, 97, 98, or 99 percent and / or 99, 95, 90, 80, 70, 60, 50, 40, 30, 20, or 10 percent or less.

[0129] Average smoothness is determined by: (1) obtaining a secondary emission / EDT detector scanning electron microscope (SEM) image of a representative sample of at least 20 microparticles; (2) selecting a square sample window centered on the SEM containing exactly 10 microparticles whose entire periphery is clearly visible (i.e., not obstructed); (3) binarizing the sample window by manual binarization with upper and lower thresholds selected to match the precise shape of the dark region of the particles; (4) for each of the 10 microparticles, selecting a square window in which the length and width of the center of the particle or near it is approximately 1 / 3 of the particle diameter (before binarizing the particle); (5) obtaining the smoothness of the 10 individual particles by dividing the dark region area within the square window by the total area of ​​the square window and multiplying the result by 100%; and (6) averaging the smoothness of these 10 individual particles to obtain the average smoothness.

[0130] In one embodiment, or in combination with any embodiment referenced herein, the CE particles have a water content at least 0.1, 0.25, 0.5, 1, 2, 4, or 5 weight percent less than the water content of the initial CE particles. For example, grinding the initial CE particles in the presence of a grinding gas, such as in a jet mill 136, is thought to reduce the water content of the CE particles compared to the initial CE particles.

[0131] In one embodiment, or in combination with any embodiment referenced herein, the CE microparticles have a cumulative amount of surfactant less than 100 ppmw, less than 75 ppmw, less than 50 ppmw, less than 25 ppmw, less than 10 ppmw, or less than 5 ppmw.

[0132] In one embodiment, or in combination with any embodiment referenced herein, the CE particles have a cumulative amount of hydrophilic colloid of less than 100 ppmw, less than 75 ppmw, less than 50 ppmw, less than 25 ppmw, less than 10 ppmw, or less than 5 ppmw.

[0133] In one embodiment, or in combination with any embodiment referenced herein, the CE fine particles have a cumulative amount of water-soluble polymer less than 100 ppmw, less than 75 ppmw, less than 50 ppmw, less than 25 ppmw, less than 10 ppmw, or less than 5 ppmw. As used herein, “water-soluble polymer” means a polymer having an insoluble content of less than 50% by weight when 1 g of the polymer is dissolved in 100 g of water at 25°C.

[0134] In one embodiment, or in combination with any embodiment referenced herein, the CE microparticles have a cumulative amount of surfactant, hydrophilic colloid, and water-soluble polymer less than 100 ppmw, less than 75 ppmw, less than 50 ppmw, less than 25 ppmw, less than 10 ppmw, or less than 5 ppmw.

[0135] In one embodiment, or in combination with any embodiment referenced herein, the CE particles have a true specific gravity of at least 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, or 0.9 and / or 1.5, 1.4, 1.3, 1.2, 1.1, 1.0, 0.9, 0.8, 0.7, or 0.6 or less, as measured according to JIS Z8807-1976.

[0136] In one embodiment, or in combination with any embodiment referenced herein, the CE particles have a bulk specific gravity of at least 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, or 0.8 and / or 1.4, 1.3, 1.2, 1.1, 1.0, 0.9, 0.8, 0.7, 0.6, or 0.5, as measured according to JIS 1201-1.

[0137] Cosmetic formulations The CE microparticles produced by the processes disclosed herein can be used to produce a variety of cosmetic compositions. Cosmetic compositions can be produced by: (1) providing a plurality of CE microparticles; (2) combining these CE microparticles with one or more cosmetic additives to form a pre-cosmetic mixture; and (3) forming a cosmetic composition from this pre-cosmetic mixture.

[0138] In one embodiment, or in combination with any other embodiment referenced herein, the cosmetic composition may contain at least 0.1, 0.5, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, or 15 weight percent of CE microparticles. Furthermore, or alternatively, the cosmetic composition may contain less than 99, 90, 80, 70, 60, 50, 40, 30, 25, 20, 15, 10, or 5 weight percent of CE microparticles. For example, the cosmetic composition may contain 0.1-90, 0.1-50, 0.1-30, 0.1-20, 0.1-15, 0.1-10, 0.1-5, 1-90, 1-50, 1-30, 1-20, 1-15, 1-10, or 1-5 weight percent of CE microparticles.

[0139] In one embodiment, or in combination with any other embodiments referenced herein, the cosmetic composition may be a foundation, sunscreen, lipstick, mascara, eyeshadow, lotion, dry shampoo, liquid shampoo, body wash, lotion, gas conditioner, skin moisturizer, face wash, tablets, foot powder, baby powder, shaving cream, or shaving gel.

[0140] In one embodiment, or in combination with any other embodiments referenced herein, the cosmetic composition may be a loose powder, compressed powder, gel, emulsion, liquid, or aerosol.

[0141] In one embodiment, or in combination with any other embodiment referenced herein, the cosmetic composition comprises at least 1, 2, 3, 4, or 5 cosmetic additives in weight of at least 1, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, or 99% by weight. Furthermore, or in an alternative form, the cosmetic composition may comprise at least 1, 2, 3, 4, or 5 cosmetic additives in weight of less than 99, 95, 90, 85, 80, 75, 70, 65, 60, 55, or 50% by weight. For example, a cosmetic composition may contain at least one, two, three, four, or five cosmetic additives in weight percent of 1-99, 1-95, 1-90, 1-85, 1-80, 5-99, 5-95, 5-90, 5-85, 10-99, 10-95, 10-85, 10-80, 15-99, 15-95, 15-90, 15-85, or 15-80.

[0142] In general, cosmetic additives may include solvents, colorants, oils, waxes, fatty acids, alcohols, esters, hydrocarbons, silicone oils, surfactants, metallic soaps, humectants, thickeners, UV absorbers, antioxidants, oil absorbers, exfoliants, water, or combinations thereof.

[0143] In one embodiment or in combination with any other embodiment referenced herein, the colorant comprises pigments (e.g., organic pigments and / or inorganic pigments) and / or dyes.

[0144] In one embodiment or in combination with any other embodiment referenced herein, the oil comprises triglycerin, soybean oil, cocoa butter, palm oil, palm kernel oil, hydrogenated oil, and / or hydrogenated castor oil.

[0145] In one embodiment or in combination with any other embodiment referenced herein, the wax comprises carnauba wax, candelilla wax, lanolin, lanolin, candelilla wax, cotton wax, montan wax, kapok wax, lanolin acetate, lanolin, and / or isopropyl lanolin fatty acid.

[0146] In one embodiment, or in combination with any other embodiment referred to herein, the fatty acids include lauric acid, myristic acid, palmitic acid, stearic acid, isostearic acid, behenic acid, oleic acid, undecylenic acid, linoleic acid, eicosapentaenoic acid (EPA), and / or docosahexaenoic acid.

[0147] In one embodiment, or in combination with any other embodiment referred to herein, the alcohol includes cetyl alcohol, stearyl alcohol, isostearyl alcohol, 2-octyldodecanol, lauryl alcohol, behenyl alcohol, myristyl alcohol, oleyl alcohol, and / or cetostearyl alcohol.

[0148] In one embodiment, or in combination with any other embodiment referred to herein, the esters include isopropyl myristate, 2-octyldodecyl myristate, cetyl 2-ethylhexanoate, diisostearyl malate, tripropylene glycol dieopenate, isononyl isononanoate, isotridyl isononanoate, cetyl octanoate, isocetyl palmitate, butyl stearate, hexyl laurate, myristyl myristate, decyl oleate, hexyl decyldimethyloctanoate, cetyl lactate, myristyl lactate, lanolin acetate, isocetyl stearate, isocetyl isostearate, cholesteryl 12-hydroxystearate, ethylene glycol di-2-ethylhexanoate, dipentaerythritol fatty acid ester, N-alkyl glycol monoisostearate, and dicapric acid. This product contains neopentyl glycol, di-2-heptyl undecanoate glycerin, tri-2-ethylhexanoate trimethylpropane, trimethylolpropane triisostearate, pentaerythritol tetra-2-ethylhexanoate, glycerin trioctanoate, glycerin triisopalmitate, trimethylolpropane triisostearate, ethylhexyl palmitate, glycerin trimyristate, tri-2-heptyl undecanoate glyceride, castor oil fatty acid methyl ester, oleyl oleate, acetoglyceride, 2-heptyl undecyl palmitate, diisobutyl adipate, N-lauroyl-L-glutamate hexyldecyl palmitate, hexyldecyl adipate, diisopropyl sebacate, ethylhexyl succinate, and / or triethyl citrate.

[0149] In one embodiment, or in combination with any other embodiment referenced herein, the hydrocarbons include paraffin, petrolatum, and / or microcrystalline waxes.

[0150] In one embodiment, or in combination with any other embodiment referenced herein, the surfactant includes anionic surfactants, cationic surfactants, and / or nonionic surfactants.

[0151] In one embodiment, or in combination with any other embodiment referenced herein, the thickener includes guar gum, pectin, starch, gelatin, collagen, cellulose derivatives, and / or mannan.

[0152] experiment Abbreviation Ex is an example; DS is the average degree of substitution; DS OH is the average degree of substitution of hydroxyl; DS Ac This is the average degree of substitution of acetyl; DS Bu M is the average degree of substitution of butyryl; w is the weight-average molecular weight; Pr2O is propionic anhydride; PrOH is propionic acid; g is grams (plural is possible). o C is degrees Celsius; Ac2O is acetic anhydride; min is a fraction; AcOH is acetic acid; Mg(OAc)2 is magnesium acetate; OAc is acetate; rt is room temperature; sorn is solution; kg is kilograms (plural).

[0153] Cellulose acetate butyrate (1) (DS Ac =2.23, DS Bu = 0.22, DS OH =0.55 M w Preparation of (=50,000-90,000)

[0154] Cellulose and an acid mixture [cellulose (5.1 parts) and AcOH (20.6 parts)] were added to a stirred reactor and immersed without heating, then the mixture was heated to 55°C. Some amount of sulfuric acid was added and the reactor was cooled to 30°C. Subsequently, a mixture of Ac2O (11 parts) and Bu2O (7.1 parts) was added, and the mixture was cooled to about 9°C while stirring. Additional sulfuric acid was added until a total of 0.8 parts was added, and the resulting reaction mixture was heated to 50°C until acylation was complete and the desired molecular weight was achieved. A mixture of AcOH (23.3 parts) and H2O (9.1 parts) was added to this reaction mixture. The mixture was then stirred at 68°C for 720 minutes, but after 80 minutes, a mixture of Mg(OAc)2 (0.77 parts), BuOH (8.7 parts), and H2O (3.4 parts) was added. After a sufficient amount of time had passed, the mixture was completely neutralized with a solution of Mg(OAc)2 (1.1 parts), BuOH (1.9 parts), and H2O (6.1 parts). The mixture was then precipitated in water by conventional methods, washed, and dried.

[0155] Degree of substitution The degree of substitution of substituents on the cellulose ester skeleton is calculated using proton nuclear magnetic resonance spectroscopy. Gel permeation chromatography is performed on cellulose ester in stabilized tetrahydrofuran. The apparatus is an Agilent 1260, consisting of a degasser, an isocratic pump with a flow rate of 1.0 ml / min, an autosampler with an injection volume of 25 microliters, a column oven set to 28°C, and a refractive index detector at 28°C. The column set consists of Agilent PLgel 5 micron guard, Mixed-C, and Oligopore in series. This system is calibrated with monodisperse polystyrene standards in the molecular weight range of approximately 4 million to 162. The sample is prepared by weighing approximately 25 milligrams of sample in 10 ml of solvent with the addition of 10 microliters of toluene to be used as a flow marker, and stirring with a stirring rod in an 8-drum screw-cap vial until dissolved.

[0156] molecular weight Molecular weight is determined by gel permeation chromatography. Gel permeation chromatography is performed on cellulose ester in stabilized tetrahydrofuran. The apparatus is an Agilent 1260, consisting of a degasser, an isocratic pump with a flow rate of 1.0 ml / min, an autosampler with an injection volume of 25 microliters, a column oven set to 28°C, and a refractive index detector at 28°C. The column set consists of Agilent PLgel 5 micron guard, Mixed-C, and Oligopore in series. This system is calibrated with monodisperse polystyrene standards in the molecular weight range of approximately 4 million to 162. The sample is prepared by weighing approximately 25 milligrams of sample in 10 ml of solvent with the addition of 10 microliters of toluene to be used as a flow marker, and stirring with a stirring rod in an 8-drum screw-cap vial until dissolved.

[0157] The cellulose esters listed in Table 1 below were prepared by adapting the preparation procedure for cellulose acetate butyrate 1. [Table 1]

[0158] Table 2 shows the properties of the cellulose esters prepared above. [Table 2]

[0159] Jet mill (jet mill grinding) Several jet mill configurations can be used to reduce particle size. Such configurations are discussed in A. Chamayo and JA Dodds, Air Jet Milling, Handbook of Powder Technology, volumes 12, Chapter 8, 2007 ("Chamayo"). Figure 7 in Chamayo shows an example of a fluidized bed opposed jet mill that can be used to reduce the size of cellulose ester particles, as listed in Table 3 below. Using the jet mill grinding process, the average particle size of cellulose ester was reduced from 300–900 μm to approximately 10 μm. The fluidized bed opposed jet mill operates as follows: Cellulose ester is placed in a hopper and introduced into the top of the mill, typically in a double-valve configuration (or via an injector) ("FEED IN"). The cellulose ester particles fall to the bottom of the mill by gravity, where they are pushed into one of three geometrically oriented high-pressure airflows, thereby forming a so-called "pulverizing zone." Within this pulverizing zone, the cellulose ester particles are reduced in size through interparticle collisions. Subsequently, the reduced-size particles are transported upward by mass transport in the vertical airflow (fluidized bed) and eventually carried into the classifier. The classifier allows for the removal of particles smaller than the desired minimum size from the mill ("FINE OUT"). Particles larger than the maximum size are excluded from the classifier, returned to the fluidized bed, and eventually returned to the grinding zone where they are further reduced in size. Particles that fall within the desired size range are discharged from the classifier into the appropriate product container. Many control parameters exist to optimize productivity, particle size, and particle size distribution shape, and these include, but are not limited to, classifier rotor speed, air nozzle pressure, and bed level.

[0160] Moisture measurement The moisture level was determined using 1 gram of material by heating the material to 115°F and measuring the Torvald moisture equilibrium.

[0161] Determination of refractive index The refractive index of the cellulose ester was determined by preparing a dope by preparing a cellulose ester film using 12 wt% solids in either a methylene chloride / methanol (9:1) or methylene chloride / ethanol (9:1) solution. The film was cast from the dope onto a glass substrate and spread evenly on the glass substrate using a casting knife. The wet dope on the glass substrate was covered and allowed to evaporate slowly for 45 minutes with the solvent still covering it. The film was then allowed to evaporate for 15 minutes without the cover. The film was peeled from the substrate, sandwiched between two sheets of paper, and weighed down to ensure the film was flattened (approximately 2 hours). The film was then sandwiched between metal frames and annealed in an oven set to 100°C for 10 minutes, and then in another oven set to 120°C for 10 minutes. The refractive index of the resulting film was measured using Metricon (Prism coupler method) at a wavelength of 589 nm.

[0162] Young's modulus The film was prepared as disclosed in the procedure for determining the refractive index. The film was cut into 6-inch pieces of 0.5-inch specimens. Young's modulus was determined by testing five specimens. Each specimen was tested in tensile mode at 0.2 inches / min up to a maximum strain of 1.6%, and then at 2 inches / min until the film broke.

[0163] Description of the OECD 301F exam In this experiment, a known concentration of the test substance, which functions as a nominal organic carbon source, is inoculated into the measured volume of inorganic culture medium. The medium is placed in a sealed flask and stirred at a constant temperature (within the range of +1°C or less) for a maximum of 60 days.

[0164] Oxygen consumption is determined using one of two methods: by measuring the amount of oxygen (electrolytically produced) required to maintain a constant gas volume in the respiratory flask, or by monitoring changes in volume or pressure (or a combination thereof).

[0165] All carbon dioxide produced during this process is absorbed using a solution of potassium hydroxide or another suitable absorbent. The amount of oxygen utilized by the microbial community during the biodegradation of the test material is calculated by subtracting the oxygen uptake by a blank inoculum (which is performed in parallel). This value is expressed as a percentage of the theoretical oxygen demand (ThOD) or, less ideally, the chemical oxygen demand (COD). [Table 3]

[0166] Table 4 shows additional CE microparticles produced by jet milling. These particles were shown to be more than 60% biodegradable under the OECD 301F biodegradation test. [Table 4]

Claims

1. A method for producing biodegradable cellulose ester (CE) fine particles, (a) To provide initial CE particles having an average particle size of at least 75 microns; (b) The method comprising grinding initial CE particles to form CE fine particles having a D50 particle size in the range of 0.5 to 50 microns.

2. The method according to claim 1, wherein the grinding in step (b) is carried out by grinding the initial CE particles with a jet mill or a bead mill.

3. The method according to any one of claims 1 to 2, further comprising reducing the size of the initial CE particles before performing the grinding in step (b).

4. The method according to claim 3, wherein the size reduction is performed by at least one of ball mill grinding, rod mill grinding, hammer mill grinding, pin mill grinding, cryogenic grinding, or gas classifier grinding.

5. The method according to any one of claims 1 to 4, wherein the grinding in step (b) reduces the D50 particle size of the initial CE particles by at least 25, 50, 75, 85, 90, or 95 percent.

6. The method according to any one of claims 1 to 5, further comprising providing a compressed gas for use in at least one of the grinding steps (b) or for use in transporting the initial CE particles to the grinding steps (b).

7. The method according to claim 6, further comprising: To supply the first portion of the compressed gas for use in the grinding of step (b); Supplying a second portion of the compressed gas for use in transporting the initial CE particles to the grinding of step (b), wherein the first portion is supplied at a higher rate than the second portion, The method, including the method described above.

8. The method according to any one of claims 1 to 7, further comprising separating the CE fine particles generated from the grinding in step (b) from the grinding gas to form a stream of CE products and a separated gas stream.

9. The method according to claim 8, further comprising recycling the separated gas stream for use in at least one of the grinding steps of step (b), or for use when transporting the initial CE particles to the grinding steps of step (b).

10. The method according to claim 9, wherein the recycling is performed by compressing the separated gas flow.

11. The method according to any one of claims 8 to 10, wherein the separation is performed by filtering the CE fine particles from the pulverizing gas.

12. The method according to any one of claims 1 to 11, further comprising collecting the crude product fraction and the fine product fraction of the CE fine particles in a separate product packaging station.

13. A system for producing cellulose ester (CE) nanoparticles, Initial CE particle source and; A compressor for generating compressed gas; A jet mill for receiving the initial CE particles and reducing their size to CE fine particles, the jet mill being supplied with a first portion of the compressed gas from the compressor; A feed system for supplying the initial CE particles to the jet mill, wherein the feed system is supplied with a second portion of the compressed gas from the compressor, The system comprising the above.

14. The system according to claim 13, further comprising a separator for receiving the CE fine particles entrained in the grinding gas from the jet mill, wherein the separator separates the CE fine particles from the grinding gas, thereby forming a CE product stream and a separated gas stream.

15. The system according to claim 14, wherein the separator comprises a filter for separating the CE fine particles from the pulverizing gas.

16. The system according to any one of claims 14 to 15, wherein the compressor compresses the separated gas flow to provide it as at least a portion of the compressed gas to at least one of the jet mill or the feed system.

17. The system according to any one of claims 13 to 16, further comprising at least one product packaging station for collecting the CE particles.

18. The system according to any one of claims 13 to 17, further comprising a splitter located downstream of the compressor for dividing the compressed gas into a first portion and a second portion.

19. The system according to any one of claims 13 to 18, wherein the feed system comprises a weight loss feeder for controlling the feed rate of the initial CE particles supplied to the jet mill.

20. The system according to any one of claims 13 to 19, wherein the feed system comprises a venturi nozzle for mixing the initial CE particles with the second portion of the compressed gas to form a particle feed flow for supply to the jet mill.

21. The system according to any one of claims 13 to 20, further comprising a mechanical mill upstream of the jet mill, the mechanical mill for pre-grinding the initial CE particles before they are supplied to the jet mill.

22. The method and / or system according to any one of claims 1 to 21, wherein the initial CE particles are in the form of at least one of powder, flakes, or pellets.

23. Biodegradable cellulose ester (CE) microparticles comprising at least one CE, wherein the CE microparticles have a D50 particle size in the range of 0.5 to 50 microns, and the CE microparticles exhibit at least 50 percent biodegradability in 60 days according to at least one of the OECD 301B, OECD 301C, OECD 301D, OECD 301F, OECD TG 310, OECD TG 306, ISO 14852, or ISO 14851 test methods, wherein the cumulative amount of surfactants, hydrophilic colloids, and water-soluble polymers present in the CE microparticles is less than 100 ppmw.

24. The method, system, and / or product according to any one of claims 1 to 23, wherein the CE fine particles exhibit an oil absorption rate of at least 0.5, 0.6, 0.7, or 0.8 g / g in accordance with ASTM D281, which uses olive oil instead of castor oil.

25. The method, system, and / or product according to any one of claims 1 to 24, wherein the CE fine particles exhibit a unimodal particle size distribution with a span in the range of 1.0 to 1.

5.

26. A method, system, and / or product according to any one of claims 1 to 25, wherein the CE comprises at least one of cellulose acetate, cellulose acetate butyrate, or cellulose acetate propionate, The CE is a hydroxyl substituent in the range of 0.6 to 2.8 ("DS ＯＨ The average degree of substitution for ) The aforementioned method, system, and / or product.

27. The method, system, and / or product according to any one of claims 1 to 26, wherein the CE fine particles have a polydispersity index of less than 0.8 and a sphericity of less than 70 percent.

28. The CE fine particles have a length of at least 0.9, or 1.0, or 1.1, or 1.2, or 1.3, or 1.4, or 1.5 m ２ / g, and / or 3.0, or 2.5, or 2.0, or 1.9, 1.8, or 1.7, or 1.6, or 1.5, or 1.4, or 1.3m ２ A method, system, and / or product according to any one of claims 1 to 27, having an average BET surface area of ​​less than or equal to / g.

29. The CE fine particles are present in a concentration of 0.2 to 0.3 g / m². ３ A method, system, and / or product according to any one of claims 1 to 28, having a bulk density in the range of .

30. The method, system, and / or product according to any one of claims 1 to 29, wherein the CE fine particles have an average smoothness of at least 10, or 20, or 30, or 40, or 0, or 60, or 70, or 80, or 90, or 95, or 95, or 97, or 98, or 99 percent, and / or 99, or 95, or 90, or 80, or 70, or 60, or 50, or 40 percent, or 30 percent, or 20 percent, or 10 percent or less.

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