Biodegradable cellulose ester microparticles and systems and methods for production thereof

Abstract

Systems and methods 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 to a D50 particle size in the range of 0.5 to 50 microns. The produced microparticles are biodegradable and have acceptable robustness and / or tactile sensation to be used as an economic substitute for conventional plastic microbeads.

Description

Background Art

[0001] Microbeads are usually spherical plastic particles with a diameter of less than 1 millimeter (mm). These particles are sometimes contained in consumer products, such as personal care products and cosmetics. Many of these products containing microbeads are designed to be applied and then washed or rinsed from the user's body. When the product containing microbeads is washed or rinsed from the user's body, the particles will be washed into the sewer and received at the municipal water treatment facility. In the past, many known microbeads were formed by plastic or polymer materials such as polyethylene, polypropylene, polymethyl methacrylate, nylon, polyurethane, etc. These materials usually have limited biodegradability. In addition, the small size of the particles limits their ability to be captured at water treatment facilities, so that the particles may be discharged from the facilities and enter larger water bodies (e.g., rivers, oceans and seas). Once in these larger water bodies, plastic or polymer microbeads may be swallowed by wild animals or cause other environmental problems. Therefore, people are exploring the possibility of producing microbead particles using more environmentally friendly materials recently. However, consumers often have high expectations for the personal care products and / or cosmetics used (including those containing micron-sized particles). For example, consumers expect these personal care and cosmetic products to exhibit certain optical properties that enable the product to blend with natural skin tone and easily hide any undesirable imperfections.

[0002] Therefore, there is a need to economically produce biodegradable microparticles that meet environmental and consumer expectations, particularly with respect to optical properties for use in personal care products and cosmetics. Summary of the invention

[0003] Provided herein is a method for producing biodegradable cellulose ester (CE) microparticles. The method comprises providing initial CE particles having an average particle size of at least 75 microns, and grinding the initial CE particles to form CE microparticles having a D50 particle size in the range of 0.5 to 50 microns.

[0004] A system for producing cellulose ester (CE) particles is also provided herein. The system includes a source of initial CE particles, a compressor for producing compressed gas, a jet mill for receiving the initial CE particles and subjecting them to size reduction into CE particles, 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 provided herein are biodegradable cellulose ester (CE) particles comprising at least one CE, wherein the CE particles have a D50 particle size in the range of 0.5 to 50 microns, wherein the CE particles exhibit at least 50% biodegradability at 60 days according to the OECD 301B test method. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Figure 1 is a schematic diagram of an exemplary process for producing cellulose ester microparticles.

[0008] Figure 2 is a schematic diagram of an example system for producing cellulose ester microparticles.

[0009] Figure 3 is a schematic diagram of an alternative system for producing cellulose ester microparticles having separate coarse product packaging stations and fine product packaging stations.

[0010] Figure 4 It is available for Figure 3 and Figure 4 Schematic diagram of an example separator of the system shown in . DETAILED DESCRIPTION

[0011] The present disclosure relates to systems and methods for producing cellulose ester (CE) microparticles. The CE microparticles are produced by grinding (e.g., jet milling) a biodegradable CE source material. The grinding is performed under process conditions that produce micron-sized CE particles having desirable qualities that make them suitable substitutes for conventional microbeads in certain consumer products. The CE microparticles can exhibit properties such as enhanced firmness and / or tactile feel, making the 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 very suitable for use in personal care products, cosmetics, and the like.

[0012] The present invention can be more easily understood by reference to the following detailed description and examples provided herein. It should be understood that the disclosure is not limited to the specific methods, preparations and conditions described, as these may vary. It should also be understood that the terms used herein are only for the purpose of describing specific aspects of the disclosed embodiments and are not intended to be limiting.

[0013] Values ​​may be expressed as "about" or "approximately" a given numerical value. Similarly, ranges may be expressed herein as from "about" one particular value and / or to "about" or another particular value. When such a range is expressed, another aspect includes from one particular value and / or to another particular value. Similarly, when values ​​are expressed as approximate values, by use of the antecedent "about", it will be understood that the particular value forms another aspect.

[0014] As used herein, the terms "a", "an", and "the" mean one or more than one.

[0015] As used herein, the term "and / or," when used in a list of two or more items, means that any one of the listed items may be used alone, or any combination of two or more of the listed items may be used. For example, if a composition is described as containing components A, B, and / or C, the composition may contain only A; only B; only C; 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.

[0016] As used herein, the terms "comprising," "comprises," and "comprise" are open transition words that are used to transition from an object recited before the term to one or more elements recited after the term, wherein the one or more elements listed after the transition word are not necessarily the only elements that make up the subject matter.

[0017] As used herein, the terms "having," "has," and "have" have the same open-ended meaning as "comprising" provided above.

[0018] As used herein, the terms "including," "include," and "included" have the same open-ended meaning as "comprising" provided above.

[0019] As used herein, "mixed cellulose esters" shall mean cellulose esters having at least two different ester substituents on a single cellulose ester polymer chain.

[0020] "Degree of substitution" is used to describe the average substitution level of substituents per anhydroglucose unit ("AGU"). In general, conventional cellulose contains three hydroxyl groups that can be substituted in each AGU unit. Therefore, DS can have a value between 0 and 3. However, low molecular weight cellulose mixed esters may have a total degree of substitution slightly higher than 3 resulting from end group contributions. Low molecular weight cellulose mixed esters will be discussed in more detail later in this disclosure. Since DS is a statistical average, a value of 1 does not guarantee that each AGU has a substituent. In some cases, there may be unsubstituted anhydroglucose units, some with two substituents and some with three substituents, and generally, this value will be a non-integer. "Total DS" is defined as the average number of all substituents per anhydroglucose unit. The degree of substitution for each AGU can also refer to a specific substituent, such as, for example, a hydroxyl, acetyl, butyryl or propionyl. In addition, the degree of substitution can specify a specific hydroxyl based on the carbon unit of the anhydroglucose unit.

[0021] When the degree of substitution refers to the hydroxyl group, DS OH When calculating the total degree of substitution, the reference is to the average hydroxyl group of each anhydroglucose that is not substituted. Therefore, DS is not used in calculating the total degree of substitution. OH .

[0022] This specification uses numerical ranges to quantify certain parameters related to the present invention. It should be understood that when numerical ranges are provided, these ranges should be interpreted as providing literal support for claim limitations that only recite the lower limit of the range and claim limitations that only recite the upper limit of the range. For example, the disclosed numerical range of 10 to 100 provides literal support for claims that recite "greater than 10" (no upper limit) and claims that recite "less than 100" (no lower limit).

[0023] This specification uses specific values ​​to quantify certain parameters related to the present invention, wherein specific values ​​do not explicitly belong to a part of a numerical range. It should be understood that each specific concrete value provided herein should be interpreted as providing extensive, intermediate and narrow ranges of text support. The wide range associated with each specific value is 60% of the value (rounded to two significant figures) plus or minus the value. The medium range associated with each specific value is 30% of the value (rounded to two significant figures) plus or minus the value. The narrow range associated with each specific value is 15% of the value (rounded to two significant figures) plus or minus the value. For example, if a specific temperature of 62 ° F is described in the specification, such a description provides text support for a wide range of values ​​from 25 ° F to 99 ° F (62 ° F + / - 37 ° F), a medium range of values ​​from 43 ° F to 81 ° F (62 ° F + / - 19 ° F), and a narrow range of values ​​from 53 ° F to 71 ° F (62 ° F + / - 9 ° F). These broad, medium, and narrow ranges apply not only to the specific values, but also to the differences between those specific values. Thus, if the specification describes a first pressure of 110 psia and a second pressure of 48 psia (a difference of 62 psi), the broad, medium, and narrow ranges for the pressure difference between the two streams would be 25 to 99 psi, 43 to 81 psi, and 53 to 71 psi, respectively.

[0024] Throughout this application, where patents or publications are cited, the entire contents of these references are intended to be incorporated by reference into this application to the extent they are not inconsistent with the present invention, in order to more fully describe the state of the art to which this invention pertains.

[0025] Reference now Figure 1, illustrates a system 100 in which cellulose 102, solvent 104, and acylating agent 106 are combined at a cellulose ester (CE) production facility 108 to produce a CE product stream 110. The CE product stream 110 may be in the form of one or more of a slurry, a wet cake, a powder, flakes, and pellets. The CE in the CE product stream 110 is a solid that is subsequently ground to produce CE microparticles 112, as will be described in more detail below.

[0026] When 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 can be directed from the unit CE production facility 108 directly to a dry grinding unit 114. The powder, flakes and / or pellets can then be ground in the dry grinding unit 114 to a desired average particle size to produce CE microparticles 112. The dry grinding unit 114 can 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.

[0027] When the CE product stream 110 is in the form of relatively dry (e.g., less than 10 wt. % moisture) flakes and / or pellets, the CE product stream 110 can first be subjected to size reduction in a size reduction unit 113 and then the product stream is ground in a dry grinding unit 114. The flakes and / or pellets can then be ground to a desired average particle size in the dry grinding unit 114 to produce CE microparticles 112. Examples of suitable size reduction units 13 include mechanical grinders, such as ball mills, rod mills, hammer mills, pin mills, and cryogenic grinders.

[0028] When the CE product stream 110 is in the form of a slurry (e.g., greater than 50 wt. % liquid), the CE product stream 110 can first be dehydrated at a dehydration unit 118 to produce a wet cake 120, and then the wet cake 120 can be dried at a drying unit 122 to produce dry CE particles 124. The dried CE particles 124 can then be ground to a desired average particle size at a dry grinding unit 114 to produce CE microparticles 112.

[0029] In another embodiment, the slurry from the CE production facility 108 is dehydrated at the dehydration unit 118 to produce a wet cake 126. The wet cake 126 can then be ground at the wet grinding unit 116 to produce a ground cake 128. The ground cake 128 can then be dried at the drying unit 130 to produce CE microparticles 112 from the solid contents of the ground cake 128.

[0030] When the CE product stream 110 is in the form of a wet cake (e.g., 10 to 50 wt. % liquid), the CE product stream 110 can be directed from the CE production facility 108 directly to the wet grinding unit 114. The wet cake can then be ground at the wet grinding unit 116 to produce a ground cake 128. The ground cake 128 can then be dried at the unit 130 to produce CE microparticles 112 from the solid content of the ground cake 128. Alternatively, the wet cake CE product stream from the CE production facility 108 can be routed to a drying unit 122 to produce dry CE particles 124. The dry CE particles 124 can then be subjected to dry grinding in the dry grinding unit 114 to produce the CE microparticles 112.

[0031] In one embodiment or in combination with any of the embodiments mentioned 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. The additives may include additives that improve grinding or additives that enhance the performance of the final CE particles. For example, zinc stearate is added at any point in the process to improve the dispersibility of the CE particles in the final formulation (i.e., to prevent agglomeration of the CE particles in the final formulation). Further, a plasticizer may be added at any point in the process to reduce the glass transition temperature of the cellulose ester. Finally, after grinding, the CE particles may be contacted with a surfactant to improve the optical properties of the CE particles. In addition, the ground CE particles may be subjected to a spheroidization step after grinding to enhance the sphericity of the CE particles. Spheroidization may be achieved, for example, by dropping the CE particles through heated air.

[0032] Cellulose esters

[0033] The cellulose esters in the CE product stream 110 can be cellulose diacetate ("CDA"), mixed cellulose esters ("MCE"), or a combination of CDA and one or more MCEs. MCEs include, for example, cellulose acetate butyrate ("CAB") and cellulose acetate propionate ("CAP").

[0034] Typically, the cellulose esters described herein can be produced by any method known in the art, such as at a CE production facility 108. Examples of methods for producing cellulose esters are taught in Kirk-Othmer, Encyclopedia of Chemical Technology, 5th Edition, Volume 5, Wil ey-Interscience, New York (2004), pages 394-444, the disclosure of which is incorporated herein by reference in its entirety. Cellulose (i.e., cellulose 102) is the starting material for producing cellulose esters and can be obtained in different grades and from sources such as, for example, cotton linters, softwood pulp, hardwood pulp, corn fiber and other agricultural sources, as well as bacterial cellulose.

[0035] One method of producing cellulose esters is by esterification. In this method, cellulose is mixed with an appropriate organic acid, anhydride and / or catalyst and then converted into a cellulose triester. The ester is then hydrolyzed by adding a water-acid mixture to the cellulose triester, which can then be filtered to remove any gel particles or fibers. Water is added to the mixture to precipitate the cellulose ester. The cellulose ester can then be washed with water to remove the byproducts of the reaction, and then dehydrated and dried as described above.

[0036] Acylating agents suitable for use herein may include, but are not limited to, alkyl or aryl carboxylic acid anhydrides, carboxylic acid halides and / or carboxylic acid esters containing the above-mentioned alkyl or aryl groups suitable for use in the acyl substituents of the substituted cellulose esters described herein. Examples of suitable carboxylic acid anhydrides include, but are not limited to, acetic anhydride, propionic anhydride, butyric anhydride, pivaloyl anhydride, benzoic anhydride and naphthoyl anhydride. Examples of carboxylic acid halides include, but are not limited to, acetyl, propionyl, butyryl, pivaloyl, benzoyl and naphthoyl chloride or bromide. Examples of carboxylic acid esters include, but are not limited to, acetyl, propionyl, butyryl, pivaloyl, benzoyl and naphthoyl methyl esters. In one or more embodiments, the acylating agent may be one or more carboxylic acid anhydrides selected from acetic anhydride, propionic anhydride, butyric anhydride, pivaloyl anhydride, benzoic anhydride and naphthoyl anhydride.

[0037] In various embodiments, the cellulose triester to be hydrolyzed may have three substituents independently selected from alkanoyl groups having 2 to 12 carbon atoms. Examples of cellulose triesters include cellulose triacetate, cellulose tripropionate, cellulose tributyrate, or mixed triesters of cellulose, such as cellulose acetate propionate and cellulose acetate butyrate. These cellulose triesters may be prepared by many methods known to those skilled in the art. For example, cellulose triesters may be prepared by reacting the cellulose triesters with a catalyst such as H 2 SO 4)Cellulose triesters can also be prepared by homogeneous acylation of cellulose dissolved in a suitable solvent such as LiCl / DMAc or LiCl / NMP.

[0038] After cellulose is esterified to triesters, some of the acyl substituents can be removed by hydrolysis or alcoholysis to obtain secondary cellulose esters. Secondary cellulose esters can also be prepared directly without hydrolysis by using a limited amount of acylating agent. This method is particularly useful when the reaction is carried out in a solvent that will dissolve cellulose.

[0039] The cellulose esters thus prepared generally contain the following structure:

[0040]

[0041] Where R 2 , R 3 and R 6 is hydrogen (provided that R 2 , R 3 and R 6 cannot be hydrogen at the same time), alkyl-acyl and / or aryl-acyl groups (such as those described above) bound to cellulose via ester linkages.

[0042] The cellulose esters prepared by these methods may have a degree of polymerization ("DP") of at least 10. In other embodiments, the cellulose esters may have a DP of at least 50, at least 100, or at least 250. In other embodiments, the cellulose esters may have a DP in the range of about 5 to about 100, or in the range of about 10 to about 50.

[0043] The present application discloses, in a first aspect, a mixed ester cellulose ester ("MCE") comprising: (1) a plurality of acetyl substituents; (2) a plurality of propionyl substituents; and (3) a plurality of hydroxyl substituents, wherein: the MCE has an average degree of substitution ("DS") of acetyl substituents of 0.1 to 2.3. Ac ”), MCE has an average degree of substitution (“DS Pr ”), MCE has an average degree of substitution (“DS OH ”).

[0044] In one embodiment or in combination with any other embodiment, class or subclass of this first aspect, wherein DS Acis 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 in the alternative, DS Ac 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.

[0045] In one embodiment or in combination with any other embodiment, class or subclass of this first aspect, wherein DS Ac 0.6 to 2.2, or 0.6 to 2.1, or 0.6 to 2.0, or 0.6 to 1.9, or 0.6 to 1.8, or 0.7 to 2.3, or 0.7 to 2.2, or 0.7 to 2.1, or 0.7 to 2.0, or 0.7 to 1.9, or 0.8 to 2.3, or 0.8 to 2.2, or 0.8 to 2.1, or 0.8 to 2.0, or 0.8 to 1.9, or 0.9 to 2.3, or 0.9 to 2.2, or 0.9 to 2.1, or 0.9 to 2.0, or 0.9 to 1.9, or 1.0 to 2.3, or 1.0 or 0.7 to 1.5, or 0.7 to 1.3, or 0.7 to 1.1, or 0.7 to 0.9.

[0046] In one embodiment or in combination with any other embodiment, class or subclass of this first aspect, wherein 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 in the alternative, DS Pr 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.

[0047] In one embodiment or in combination with any other embodiment, class or subclass of this first aspect, wherein DS Pr is from 0.1 to 0.9, or from 0.1 to 0.85, or from 0.1 to 0.8, or from 0.1 to 0.75, or from 0.1 to 0.7, or from 0.1 to 0.6, or from 0.1 to 0.5, or from 0.1 to 0.4, or from 0.15 to 0.95, or from 0.15 to 0.9, or from 0.15 to 0.85, or from 0.15 to 0.8, or from 0.15 to 0.75, or from 0.15 to 0.7, or from 0.15 to 0.65, or from 0.2 to 0.95, or from 0.2 to 0.9, or 0.2 to 0.85, or 0.2 to 0.8, or 0.2 to 0.75, or 0.2 to 0.7, or 0.2 to 0.65, 0.25 to 0.95, or 0.25 to 0.9, or 0.25 to 0.85, or 0.25 to 0.8, or 0.25 to 0.75, or 0.25 to 0.7, or 0.25 to 0.65, or 0.3 to 0.95, or 0.3 to 0.9, or 0.3 to 0.85, or 0.3 to 0.8, or 0.3 to 0. 75, or 0.3 to 0.7, or 0.3 to 0.65, or 0.35 to 0.95, or 0.35 to 0.9, or 0.35 to 0.85, or 0.35 to 0.8, or 0.35 to 0.75, or 0.35 to 0.7, or 0.35 to 0.65, or 0.4 to 0.95, or 0.4 to 0.9, or 0.4 to 0.85, or 0.4 to 0.8, or 0.4 to 0.75, or 0.4 to 0.7, or 0.4 to 0.65, or 0. or 0.5 to 0.85, or 0.5 to 0.8, or 0.5 to 0.75, or 0.5 to 0.7, or 0.5 to 0.65, or 0.5 to 0.95, or 0.45 to 0.9, or 0.45 to 0.85, or 0.5 to 0.8, or 0.5 to 0.75, or 0.5 to 0.7, or 0.5 to 0.65, or 0.1 to 0.9, or 0.1 to 0.85, or 0.1 to 0.8.

[0048] In one embodiment or in combination with any other embodiment, class or subclass of this first aspect, wherein 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 in the alternative, DS OHLess 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.

[0049] In one embodiment or in combination with any other embodiment, class or subclass of this first aspect, wherein DS OH 0.5 to 1.5, or 0.5 to 1.45, or 0.5 to 1.40, or 0.5 to 1.35, or 0.5 to 1.30, or 0.5 to 1.25, or 0.5 to 1.2, or 0.5 to 1.15, or 0.5 to 1.1, or 0.5 to 1.05, or 0.5 to 1.0, or 0.5 to 0.95 or 0.5 to 0.9, or 0.55 to 1.5, or 0.55 to 1.45, or 0.55 to 1.40, or 0.55 to 1.35, or 0.55 to 1.30, or 0.55 to 1.25, or 0.55 to 1.2, or 0.55 to 1.15, or 0.55 to 1.1, or 0.55 to 1.05, or 0.55 to 1.0, or 0.55 to 0.95, or 0.55 to 0.9, or 0.6 to 1.5, or 0.6 to 1.45, or 0.6 to 1.40, or 0.6 to 1.35, or 0.6 to 1.30, or 0.6 to 1.25, or 0. 6 to 1.2, or 0.6 to 1.15, or 0.6 to 1.1, or 0.6 to 1.05, or 0.6 to 1.0, or 0.6 to 0.95, or 0.6 to 0.9, or 0.65 to 1.5, or 0.65 to 1.45, or 0.65 to 1.40, or 0.65 to 1.35, or 0.65 to 1.30, or 0.65 to 1.25, or 0.65 to 1.2, or 0.65 to 1.15, or 0.65 to 1.1, 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 0.65 to 0.9, or 0.7 to 1.5, or 0.7 to 1.45, or 0.7 to 1.40, or 0.7 to 1.35, or 0.7 to 1.30, 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.

[0050] In one embodiment or in combination with any other embodiment, class or subclass of this first aspect, wherein DS Pr and DS AcThe sum of is 1.9 to 2.44, or 1.9 to 2.0, or 1.9 to 2.1, or 1.9 to 2.2, or 1.9 to 2.3, or 2.0 to 2.44, or 2.0 to 2.1, or 2.0 to 2.2, or 2.0 to 2.3, or 2.1 to 2.44, or 2.1 to 2.2, or 2.1 to 2.3, or 2.2 to 2.44, or 2.2 to 2.3.

[0051] In one embodiment or in combination with any other embodiment, class, or subclass of this first aspect, the ratio of hydroxyl substituents to acetyl substituents of the mixed cellulose ester is 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. Additionally, in alternatives, the ratio of hydroxyl substituents to acetyl substituents of the mixed cellulose ester is 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.

[0052] In one embodiment or in combination with any other embodiment, class, or subclass of this first aspect, the ratio of hydroxyl substituents to propionyl substituents of the MCE is 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. Additionally or in the alternative, the ratio of hydroxyl substituents to propionyl substituents of the MCE is 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.

[0053] In one embodiment or in combination with any other embodiments, classes or subclasses of this first aspect, 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 at 60 days according to at least one of the OECD 301B, OECD 301C, OECD 301D, OECD 301F, OECD TG 310, OECDTG 306, ISO 14852, or ISO 14851 test methods.

[0054] In one embodiment or in combination with any other embodiments, classes or subclasses of this first aspect, 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 at 60 days according to at least one of the OECD 301B, OECD 301C, OECD 301D, OECD 301F, OECD TG 310, OECDTG 306, ISO 14852, or ISO 14851 test methods.

[0055] In one embodiment or in combination with any other embodiment, class or subclass of this first aspect, 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.

[0056] The present application discloses, in a second aspect, a mixed cellulose ester ("MCE") comprising: (1) a plurality of acetyl substituents; (2) a plurality of propionyl substituents; and (3) a plurality of hydroxyl substituents, wherein: the MCE has an average degree of substitution ("DS") of acetyl substituents of 0.1 to 1.2. Ac ”), MCE has an average degree of substitution (“DS Pr”), and the MCE has an average degree of substitution (“DS OH ”).

[0057] In one embodiment or in combination with any other embodiment, class or subclass of this second aspect, wherein 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 in the alternative, DS Ac 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.

[0058] In one embodiment or in combination with any other embodiment, class or subclass of this second aspect, wherein DS Ac is from 0.6 to 0.7, or from 0.6 to 0.8, or from 0.6 to 0.9, or from 0.6 to 1.0, or from 0.6 to 1.1, or from 0.7 to 0.9, or from 0.7 to 1.0, or from 0.7 to 1.1, or from 0.7 to 1.2, or from 0.8 to 0.9, or from 0.8 to 1.0, or from 0.8 to 1.1, or from 0.8 to 1.2, or from 0.9 to 1.0, or from 0.9 to 1.1, or from 0.9 to 1.2, or from 1.0 to 1.1, or from 1.0 to 1.2, or from 1.1 to 1.2.

[0059] In one embodiment or in combination with any other embodiment, class or subclass of this second aspect, wherein 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 in the alternative, DS Pr 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.

[0060] In one embodiment or in combination with any other embodiment, class or subclass of this second aspect, wherein DS Pris from 1.05 to 1.35, or from 1.05 to 1.3, or from 1.05 to 1.25, or from 1.05 to 1.2, or from 1.05 to 1.15, or from 1.05 to 1.1, or from 1.1 to 1.4, or from 1.1 to 1.35, or from 1.1 to 1.3, or from 1.1 to 1.25, or from 1.1 to 1.2, or from 1.1 to 1.15, or from 1.15 to 1.4, or 1.15 to 1.35, or 1.15 to 1.3, or 1.15 to 1.25, or 1.15 to 1.2, or 1.2 to 1.4, or 1.2 to 1.35, or 1.2 to 1.3, or 1.2 to 1.25, or 1.25 to 1.4, or 1.25 to 1.35, or 1.25 to 1.3, or 1.3 to 1.4, or 1.3 to 1.35.

[0061] In one embodiment or in combination with any other embodiment, class or subclass of this second aspect, wherein 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 in the alternative, DS OH 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.

[0062] In one embodiment or in combination with any other embodiment, class or subclass of this second aspect, wherein DS OH75 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 to 1.4, or 0.8 to 1.35, or 0.8 to 1.3, or 0.8 to 1.25, or 0.8 to 1.2, or 0.8 to 1.15, or 0.8 to 1.1, or 0.8 to 1.05, or 0.85 to 1.4, or 0.85 to 1.35, or 0.85 to 1.3, or 0.85 to 1.25, or 0.85 to 1.2, or 0.85 to 1.15, or 0.85 to 1.1, or 0.85 to 1.05, or 0.9 to 1.4, or 0.9 to 1.35, or 0.9 to 1.3, or 0.9 to 1.25, or 0.9 to 1.2, or 0.9 to 1.15, or 0.9 to 1.1, or 0.9 to 1.05.

[0063] In one embodiment or in combination with any other embodiment, class, or subclass of this second aspect, the mixed cellulose ester has a ratio of hydroxyl substituents to acetyl substituents 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. Additionally, in alternatives, the mixed cellulose ester has a ratio of hydroxyl substituents to acetyl substituents 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.

[0064] In one embodiment or in combination with any other embodiment, class, or subclass of this second aspect, the MCE has a ratio of hydroxyl substituents to propionyl substituents 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. Additionally or in the alternative, the MCE has a ratio of hydroxyl substituents to propionyl substituents 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.

[0065] In one embodiment or in combination with any other embodiment, class or subclass of this second aspect, wherein DS Pr and DS Ac the sum of is 1.65 to 2.3, or 1.65 to 2.2, or 1.65 to 2.1, or 1.65 to 2.0, or 1.65 to 1.9, or 1.65 to 1.8, or 1.7 to 2.3, or 1.7 to 2.2, or 1.7 to 2.1, or 1.7 to 2.0, or 1.7 to 1.9, or 1.7 to 1.8, or 1.75 to 2.3, or 1.75 to 2.2, or 1.75 to 2.1, or 1.75 to 2.0, or 1.75 to 1.9, or 1.8 to 2.3, or 1.8 to 2.2, or 1.8 to 2.1, or 1.8 to 2.0, or 1.8 to 1.9, or 1.9 to 2.3, or 1.9 to 2.2, or 1.9 to 2.1, or 1.9 to 2.0, or 2.0 to 2.3, or 2.0 to 2.2, or 2.0 to 2.1.

[0066] In one embodiment or in combination with any other embodiment, class or subclass of this second aspect, wherein DS OH0.6 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 to 1.4, or 0.8 to 1.35, or 0.8 to 1.3, or 0.8 to 1.25, or 0.8 to 1.2, or 0.8 to 1.15, or 0.8 to 1.1, or 0.8 to 1.05, or 0.85 to 1.4, or 0.85 to 1.35, or 0.85 to 1.3, or 0.85 to 1.25, or 0.85 to 1.2, or 0.85 to 1.15, or 0.85 to 1.1, or 0.85 to 1.05, or 0.9 to 1.4, or 0.9 to 1.35, or 0.9 to 1.3, or 0.9 to 1.25, or 0.9 to 1.2, or 0.9 to 1.15, or 0.9 to 1.1, or 0.9 to 1.05.

[0067] In one embodiment or in combination with any other embodiments, classes or subclasses of this second aspect, 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 at 60 days according to at least one of the OECD 301B, OECD 301C, OECD 301D, OECD 301F, OECD TG 310, OECDTG 306, ISO 14852, or ISO 14851 test methods.

[0068] In one embodiment or in combination with any other embodiments, classes or subclasses of this second aspect, 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 at 60 days according to at least one of the OECD 301B, OECD 301C, OECD 301D, OECD 301F, OECD TG 310, OECDTG 306, ISO 14852, or ISO 14851 test methods.

[0069] In one embodiment or in combination with any other embodiment, class or subclass of this second aspect, 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.

[0070] The present application also discloses a mixed cellulose ester ("MCE") in a third aspect, comprising: (1) a plurality of acetyl substituents; (2) a plurality of butyryl substituents; and (3) a plurality of hydroxyl substituents, wherein: the MCE has an average degree of substitution ("DS") of acetyl substituents of 0.1 to 2.4. Ac ”), MCE has an average degree of substitution (“DS Bu ”), MCE has an average degree of substitution (“DS OH ”).

[0071] In one embodiment or in combination with any other embodiment, class or subclass of this first aspect, wherein 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 in the alternative, DS AcLess 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.

[0072] In one embodiment or in combination with any other embodiment, class or subclass of this third aspect, wherein DS Acis from 0.9 to 2.4, from 0.9 to 2.3, or from 0.9 to 2.2, or from 0.9 to 2.1, or from 0.9 to 2.0, or from 0.9 to 1.9, or from 0.9 to 1.8, or from 0.9 to 1.7, or from 0.9 to 1.6, or from 0.9 to 1.4, 0.9 to 1.3, or from 0.9 to 1.2, or from 0.9 to 1.1, or from 0.9 to 1.0, or 0.92 to 2.4, 0.92 to 2.3, or 0.92 to 2.2, or 0.92 to 2.1, or 0.92 to 2.0, or 0.92 to 1.9, or 0.92 to 1.8, or 0.92 to 1.7, or 0.92 to 1.6, or 0.92 to 1.4, 0.92 to 1.3, or 0.92 to 1.2, or 0.92 to 1 .1, or 0.92 to 1.0, or 0.94 to 2.4, 0.94 to 2.3, or 0.94 to 2.2, or 0.94 to 2.1, or 0.94 to 2.0, or 0.94 to 1.9, or 0.94 to 1.8, or 0.94 to 1.7, or 0.94 to 1.6, or 0.94 to 1.4, 0.94 to 1.3, or 0.9 4 to 1.2, or 0.94 to 1.1, or 0.94 to 1.0, or 0.96 to 2.4, 0.96 to 2.3, or 0.96 to 2.2, or 0.96 to 2.1, or 0.96 to 2.0, or 0.96 to 1.9, or 0.96 to 1.8, or 0.96 to 1.7, or 0.96 to 1.6, or 0.96 to 1.4, 0.96 to 1.3, or 0.96 to 1.2, or 0.96 to 1.1, or 0.96 to 1.0, or 0.98 to 2.4, 0.98 to 2.3, or 0.98 to 2.2, or 0.98 to 2.1, or 0.98 to 2.0, or 0.98 to 1.9, or 0.98 to 1.8, or 0.98 to 1.7, or 0.98 to 1 .6, 0.98 to 1.4, 0.98 to 1.3, or 0.98 to 1.2, or 0.98 to 1.1, or 0.98 to 1.0, or 1.0 to 2.4, 1.0 to 2.3, or 1.0 to 2.2, or 1.0 to 2.1, or 1.0 to 2.0, or 1.0 to 1.9, or 1.0 to 1.8, or 1.0 to 1.7, or 1. 0 to 1.6, or 1.0 to 1.4, or 1.0 to 1.3, 1.0 to 1.2, or 1.0 to 1.1, or 1.1 to 2.4, or 1.1 to 2.3, or 1.1 to 2.2, or 1.1 to 2.1, or 1.1 to 2.0, or 1.1 to 1.9, or 1.1 to 1.8, or 1.1 to 1.7, or 1.1 to 1.6, 1.1 to 1.4, or 1.1 to 1.3, or 1.1 to 1.2, or 1.2 to 2.4, or 1.2 to 2.3, or 1.2 to 2.2, or 1.2 to 2.1, or 1.2 to 2.0, or 1.2 to 1.9, or 1.2 to 1.8, or 1.2 to 1.7, or 1.2 to 1.6, or 1.2 to 1.4, or 1.2 to 1.3, or 1.3 to 2.4, or 1.3 to 2.3, or 1.3 to 2.2, or 1.3 to 2.1, or 1.3 to 2.0, or 1.3 to 1.9, or 1.3 to 1.8, or 1.3 to 1.7, or 1.3 to 1.6, or 1.3 to 1.4, or 1.4 to 2.4, or 1.4 to 2.3, or 1.4 to 2.2, or 1.4 to 2.1, or 1.4 to 2.0, or 1.4 to 1.9, or 1.4 to 1.8, or 1.4 to 1.7, or 1.4 to 1.6, or 1.5 to 2.4, or 1.5 to 2.3, or 1.5 to 2.2, or 1.5 to 2.1, or 1.5 to 2.0, or 1.5 to 1.9, or 1.5 to 1.8, or 1.5 to 1.7, or 1.5 to 1.6, or 1.6 to 2.4, or 1.6 to 2 .3, or 1.6 to 2.2, or 1.6 to 2.1, or 1.6 to 2.0, or 1.6 to 1.9, or 1.6 to 1.8, or 1.6 to 1.7, or 1.7 to 2.4, or 1.7 to 2.3, or 1.7 to 2.2, or 1.7 to 2.1, or 1.7 to 2.0, or 1.7 to 1.9, or 1.7 to 1.8, or 1.8 to 2.3, or 1. 8 to 2.1, or 1.8 to 2.0, or 1.8 to 1.9, or 1.9 to 2.3, or 1.9 to 2.2, or 1.9 to 2.1, or 1.9 to 2.0, or 2.0 to 2.4, or 2.0 to 2.3, or 2.0 to 2.2, or 2.0 to 2.1, or 2.1 to 2.4, or 2.1 to 2.3, or 2.1 to 2.2, or 2.2 to 2.3. .

[0073] In one embodiment or in combination with any other embodiment, class or subclass of this third aspect, wherein DS Bu 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 in the alternative, DS Bu 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.

[0074] In one embodiment or in combination with any other embodiment, class or subclass of this third aspect, wherein DS Bu0.1 to 1.35, or 0.1 to 1.3, or 0.1 to 1.25, or 0.1 to 1.2, or 0.1 to 1.15, or 0.1 to 1.1, or 0.1 to 1.0, or 0.1 to 0.8, or 0.1 to 0.6, or 0.2 to 1.35, or 0.2 to 1.3, or 0.2 to 1.25, or 0.2 to 1.2, or 0. 0.2 to 1.15, or 0.2 to 1.1, or 0.2 to 1.0, or 0.2 to 0.8, or 0.2 to 0.6, or 0.2 to 0.4, or 0.3 to 1.35, or 0.3 to 1.3, or 0.3 to 1.25, or 0.3 to 1.2, or 0.3 to 1.15, or 0.3 to 1.1, or 0.3 to 1.0, or 0.3 to 0 .8, or 0.3 to 0.6, or 0.3 to 0.5, or 0.4 to 1.35, or 0.4 to 1.3, or 0.4 to 1.25, or 0.4 to 1.2, or 0.4 to 1.15, or 0.4 to 1.1, or 0.4 to 1.0, or 0.4 to 0.8, or 0.4 to 0.6, or 0.5 to 1.35, or 0.5 to 1.3, or 0.5 to 1.25, or 0.5 to 1.2, or 0.5 to 1.15, or 0.5 to 1.1, or 0.5 to 1.0, or 0.5 to 0.8, or 0.5 to 0.7, or 0.6 to 1.35, or 0.6 to 1.3, or 0.6 to 1.25, or 0.6 to 1.2, or 0.6 to 1.15, or 0.6 to 1.1, or 0.6 to 1.0, or 0.6 to 0.8, 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 1.0, or 0.8 to 1.35, or 0.8 to 1.3, or 0.8 to 1.25, or 0.8 to 1.2, or 0.8 to 1 .15, or 0.8 to 1.1, or 0.8 to 1.0, or 0.9 to 1.35, or 0.9 to 1.3, or 0.9 to 1.25, or 0.9 to 1.2, or 0.9 to 1.15, or 0.9 to 1.1, or 1.0 to 1.35, or 1.0 to 1.3, or 1.0 to 1.25, or 1.0 to 1.2, or 1.0 to 1.1 5, or 1.0 to 1.1, or 1.05 to 1.35, or 1.05 to 1.3, or 1.05 to 1.25, or 1.05 to 1.2, or 1.05 to 1.15, or 1.05 to 1.1, or 1.1 to 1.4, or 1.1 to 1.35, or 1.1 to 1.3, or 1.1 to 1.25, or 1.1 to 1.2, or 1.1 to 1.15, or 1.15 to 1.4, or 1.15 to 1.35, or 1.15 to 1.3, or 1.15 to 1.25, or 1.15 to 1.2, or 1.2 to 1.4, or 1.2 to 1.35, or 1.2 to 1.3, or 1.2 to 1.25, or 1.25 to 1.4, or 1.25 to 1.35, or 1.25 to 1.3, or 1.3 to 1.4, or 1.3 to 1.35. .

[0075] In one embodiment or in combination with any other embodiment, class or subclass of this third aspect, wherein 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 in the alternative, DS OH 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.

[0076] In one embodiment or in combination with any other embodiment, class or subclass of this third aspect, wherein DS OH is from 0.5 to 1.0, or from 0.5 to 0.95, or from 0.5 to 0.9, or from 0.5 to 0.85, or from 0.5 to 0.8, or from 0.5 to 0.75, or from 0.5 to 0.7, or from 0.5 to 0.65, or from 0.5 to 0.6, or from 0.5 to 0.55, or from 0.55 to 1.0, or from 0.55 to 0.95, or from 0.55 to 0.9, or from 0.55 to 0.85, or from 0.55 to 0.8, or from 0.55 to 0.75, or from 0.55 to 0.7, or or 0.65 to 0.75, or 0.6 to 0.8, or 0.6 to 0.85, or 0.6 to 0.9, or 0.6 to 0.95, or 0.6 to 1.0, or 0.65 to 0.7, or 0.65 to 0.75, or 0.65 to 0.8, or 0.65 to 0.85, or 0.65 to 0.9, or 0.65 to 0.95, or 0.65 to 1.0.

[0077] In one embodiment or in combination with any other embodiment, class or subclass of this third aspect, wherein DS Bu and DS AcThe sum of is 1.65 to 2.3, or 1.65 to 2.2, or 1.65 to 2.1, or 1.65 to 2.0, or 1.65 to 1.9, or 1.65 to 1.8, or 1.7 to 2.3, or 1.7 to 2.2, or 1.7 to 2.1, or 1.7 to 2.0, or 1.7 to 1.9, or 1.7 to 1.8, or 1.75 to 2.3, or 1.75 to 2.2, or 1.7 5 to 2.1, or 1.75 to 2.0, or 1.75 to 1.9, or 1.8 to 2.3, or 1.8 to 2.2, or 1.8 to 2.1, or 1.8 to 2.0, or 1.8 to 1.9, or 1.9 to 2.3, or 1.9 to 2.2, or 1.9 to 2.1, or 1.9 to 2.0, or 2.0 to 2.4, or 2.0 to 2.3, or 2.0 to 2.2, or 2.0 to 2.1.

[0078] In one embodiment or in combination with any other embodiment, class, or subclass of this third aspect, the mixed cellulose ester has a ratio of hydroxyl substituents to acetyl substituents 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. Additionally, in alternatives, the mixed cellulose ester has a ratio of hydroxyl substituents to acetyl substituents 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.

[0079] In one embodiment or in combination with any other embodiments, classes, or subclasses of this third aspect, the mixed cellulose ester has a ratio of hydroxyl substituents to butyryl substituents 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. Additionally, or in the alternative, the mixed cellulose ester has a ratio of hydroxyl substituents to butyryl substituents 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.

[0080] In one embodiment or in combination with any other embodiments, classes or subclasses of this third aspect, 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 at 60 days according to at least one of the OECD 301B, OECD 301C, OECD 301D, OECD 301F, OECD TG 310, OECDTG 306, ISO 14852, or ISO 14851 test methods.

[0081] In one embodiment or in combination with any other embodiment, class or subclass of this third aspect, 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.

[0082] In one embodiment or in combination with any of the embodiments mentioned herein, the CE that is ground to produce the CE particles 112 can be a mixed cellulose ester of the first aspect, the second aspect, and / or the third aspect, including any classes or subclasses of these aspects.

[0083] system

[0084] Reference now Figure 2 , illustrates a method for producing CE particles 112 (eg Figure 1 In one embodiment, a dry grinding system 132 is used. Figure 2 The dry grinding system as Figure 1 The dry grinding unit 114. Figure 2 In the embodiment illustrated in FIG. 1 , CE particles 134 are provided by a feed system to a jet mill 136 to produce CE microparticles 112 having a desired average particle size. The feed system may include a source 138 of CE particles, a feeder 140, and / or a nozzle 142.

[0085] In one embodiment or in combination with any of the embodiments mentioned herein, the source 138 of CE particles comprises a CE production facility 108 ( Figure 1Additionally or alternatively, the source 138 of CE particles can be a package (such as a super bag) containing pre-made CE particles 134 received from a CE manufacturer.

[0086] CE particles 134 discharged from source 138 are received at feeder 140, which is used to control the feed rate of initial CE particles 134 provided to jet mill 136. Providing CE particles 134 to jet mill 136 at a controlled and substantially constant feed rate enables CE particles 134 to undergo size reduction to a desired average particle size. In one embodiment or in combination with any of the embodiments mentioned herein, feeder 140 is a loss-in-weight feeder.

[0087] Prior to being provided to the jet mill 136, the CE particles 134 discharged from the feeder 140 are received at the nozzle 142. The CE particles 134 are combined with a portion of a compressed gas 144 (e.g., compressed air) as will be described in more detail below at the nozzle 142 to form a particle feed stream 146. Combining the CE particles 134 with the compressed gas 144 facilitates conveying the CE particles 134 to the jet mill 136 in an efficient and controllable manner. In one embodiment or in combination with any of the embodiments mentioned herein, the nozzle 142 is a venturi nozzle. Thus, the pressure differential formed by the compressed gas 144 within the nozzle 142 is used to draw the CE particles 134 from the feeder 140 to the nozzle 142, thereby forming the particle feed stream 146.

[0088] The system 132 also includes a compressor 148 for producing compressed gas 144. The compressed gas 144 can be produced by the compressor 148 from ambient air and / or from a separated gas stream 150, as will be described in more detail below. When the amount of separated / recycled 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 of the embodiments mentioned herein, the compressed gas 144 discharged from the compressor 148 is provided to at least one jet mill 136, or used to convey the CE particles 134 to the jet mill 136.

[0089] For example, system 132 includes a flow splitter 152 downstream of compressor 148 for splitting compressed gas 144 into a first portion 154 and a second portion 156. As described above, first portion 154 is provided to jet mill 136, while second portion 156 is provided to nozzle 142 of the feed system.

[0090] In the illustrated embodiment, a pressure regulator 158 is positioned between the flow divider 152 and the jet mill 136. The pressure regulator 158 regulates the pressure and / or velocity of the first portion 154 of the compressed gas 144 to produce a milling gas 160 to be supplied to the jet mill 136. This pressure regulation can be based on a desired particle size distribution of CE microparticles 112 produced from the CE particles 134 by the jet mill 136. In one embodiment or in combination with any of the embodiments mentioned herein, the milling gas 160 (i.e., the regulated first portion 154) is supplied to the jet mill 136 at a greater velocity than the second portion 156 supplied to the nozzle 142.

[0091] In an alternative embodiment, the nozzle 142 is placed between the regulator 158 and the jet mill 136. The milling gas 160 will be fed directly into the nozzle 142 to feed the particle stream 146 into the jet mill. In this arrangement, the second portion 156 will not be fed into the nozzle 142.

[0092] In one embodiment or in combination with any of the embodiments mentioned herein, the jet mill 136 is a high-speed fluid energy impact mill that circulates the CE particles 134 entrained in the grinding gas 160. The jet mill 136 generally does not include any moving parts. Thus, the CE particles 134 are subjected to size reduction by promoting collisions between individual particles and / or between particles and portions of the jet mill 136 itself.

[0093] As described above, the particle size distribution of the resulting CE microparticles 112 produced in the jet mill 136 is controlled based on the pressure and / or velocity of the milling gas 160 supplied to the jet mill 136. In one embodiment or in combination with any of the embodiments mentioned herein, the milling 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%.

[0094] The milled CE stream 164 (including the CE particles 112 entrained in the milling gas 160) is provided from the jet mill 136 to a separator 166. The separator 166 separates the CE particles 112 from the milling gas 160, thereby forming a CE particle stream 168 and a separated gas stream 150. In one embodiment or in combination with any of the embodiments mentioned herein, the separation is performed by filtering the CE particles 112 from the milling gas 160.

[0095] For example, refer to Figure 4, the separator 166 includes a housing 170 and a filter 172 positioned therein. The housing 170 receives the milled CE stream 164, and the filter 172 separates the CE particles 112 from the milling gas 160. Thus, the CE particles 112 formed by the milling gas 160 and the separated gas stream 150 are discharged from the housing 170 in separate streams. In addition, a pulse gas 174 can be provided to the housing 170 to drive off any particles collected on the filter 172.

[0096] Reference again Figure 2 , the separated gas stream 150 can be recycled / recycled for use in at least one jet mill 136, or for conveying the initial CE particles to the jet mill 136 via the nozzle 142, as described above. In one embodiment or in combination with any of the embodiments mentioned herein, the recycling is performed by compressing the separated gas stream 150 in a compressor 148, thereby producing a compressed gas 144.

[0097] The microparticle CE product stream 168 may be delivered to at least one product packaging station 176 for collecting the CE microparticles 112. Figure 2 , the particulate CE product stream 168 is conveyed to a single product packaging station 176 which collects all of the CE particles 112 contained therein, regardless of relative particle size.

[0098] refer to Figure 3 , the CE microparticles are collected at separate product packaging stations, such as the first product packaging station 178 and the second product packaging station 180. In one embodiment or in combination with any of the embodiments mentioned herein, the rotational circulation of the CE particles 134 within the jet mill 136 can produce CE microparticle fractions of different sizes at different radial regions within the jet mill 136.

[0099] In one embodiment or in combination with any of the embodiments mentioned herein, a first product packaging station 178 is used to collect a coarse product fraction 182 of CE microparticles, and a second product packaging station 180 is used to collect a fine product fraction 184 of CE microparticles. In the illustrated embodiment, the first product packaging station 178 receives the coarse 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, the separator 166 is positioned between the jet mill 136 and the second product packaging station 180.

[0100] Initial CE particles

[0101] As described above, the initial CE particles used to produce CE microparticles can be sourced from a CE production facility such as Figure 1 facilities illustrated in ) and / or received in bulk packaging from CE manufacturers.

[0102] In one embodiment or in combination with any of the embodiments mentioned herein, the initial CE particles have an average particle size of at least 75 microns.

[0103] In one embodiment or in combination with any of the embodiments mentioned herein, the initial CE pellets are in the form of at least one of a powder, flakes or pellets.

[0104] In one embodiment or in combination with any of the embodiments mentioned 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 not more than 1500, 1250, 1000, 900, 800, 700, 600 or 500 microns.

[0105] In one embodiment or in combination with any embodiment mentioned 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 not more than 10000, 8000, 6000, 4000, or 2000 microns.

[0106] In one embodiment or in combination with any embodiment mentioned herein, the initial CE particles are in the form of granules having an average particle size of at least 500, 1000, 1500, 2000, 2500, or 3000 microns, and / or not more than 20000, 15000, 10000, 8000, 6000, 5000, 4000, or 3000 microns.

[0107] The average particle size of the initial CE granules (e.g., powder, flakes, or pellets) is determined by measuring the maximum external dimension of 30 randomly selected representative particles and calculating the average of these 30 maximum external dimension values. The maximum external dimension is measured by capturing a two-dimensional image of at least 30 representative particles whose maximum external dimension is clearly visible. The maximum external dimension of the 30 particles in the two-dimensional image is measured electronically or manually using a caliper-type measurement technique.

[0108] In one embodiment or in combination with any of the embodiments mentioned herein, the initial CE particles comprise CE in an amount of at least 50, 60, 70, 80, 90, 95 or 99 wt%.

[0109] In one embodiment or in combination with any of the embodiments mentioned herein, the initial CE particles have a moisture content in the range of 0.5-10 wt%, 0.5-8.0 wt%, 0.5-6.0 wt% or 0.5-5.0 wt%.

[0110] CE Microparticles

[0111] The CE microparticles produced by the methods disclosed herein exhibit enhanced firmness and / or tactile feel, for example, making them suitable for use in personal care products, cosmetics, and the like.

[0112] In one embodiment or in combination with any of the embodiments mentioned herein, the CE microparticles have a range of from 0.5 to 100, 1 to 100, 1 to 80, 1 to 70, 1 to 60, 1 to 50, 1 to 40, 1 to 35, 1 to 30, 1 to 25, 1 to 20, 1 to 15, 1 to 10, 2 to 100, 2 to 80, 2 to 70, 2 to 60, 2 to 50, 2 to 40, 2 to 35, 2 ... 2 to 25, 2 to 20, 2 to 15, 2 to 10, 3 to 100, 3 to 80, 3 to 70, 3 to 60, 3 to 50, 3 to 40, 3 to 35, 3 to 30, 3 to 25, 3 to 20, 3 to 15, 3 to 10, 5 to 100, 5 to 80, 5 to 70, 5 to 60, 5 to 50, 5 to 40, 5 to 35, 5 to 30, 5 to 25, 5 to 20, 5 to 15, 5 to 10 , 10 to 100, 10 to 80, 10 to 70, 10 to 60, 10 to 50, 10 to 40, 10 to 35, 10 to 30, 10 to 25, 10 to 20, 10 to 15, 15 to 100, 15 to 80, 15 to 70, 15 to 60, 15 to 50, 15 to 40, 15 to 35, 15 to 30, 15 to 25, 15 to 20, 20 to 100, 20 to 80 , 20 to 70, 20 to 60, 20 to 50, 20 to 40, 20 to 35, 20 to 30, 25 to 100, 25 to 80, 25 to 70, 25 to 60, 25 to 50, 25 to 40, 25 to 35, 25 to 30, 30 to 100, 30 to 80, 30 to 70, 30 to 60, 30 to 50, 30 to 40, or 30 to 35 microns. For example, the hardened CE microparticles can 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.

[0113] As used herein, the term "D50" means that 50% of the microparticles, based on volume, have a maximum dimension less than or equal to the noted value (e.g., 10 microns). The D50 value can also be considered the median particle size. To ensure that a representative D50 value is obtained, the sample size of the microparticles should be at least 0.5 grams. The microparticle sample size is then dispersed and mixed in 1.5 ounces of isopropyl alcohol or an aqueous surfactant solution (1 drop of 5% v / v CO-630 surfactant). The D50 is tested by laser diffraction and a computer algorithm using the Mie theory for generating particle size distribution. A suitable particle size analyzer for determining the D50 value is the Malvern Mastersizer 3000 from Malvern Panalytical. When using the Malvern Mastersizer, the obscuration can be set between 2% and 5%, and the sample measurement time for both red and blue light measurements is set to three seconds. The dispersed sample is added until the desired obscuration is achieved (approximately 4%) and then the measurement is taken. After the first measurement, the sample is sonicated at 50% power for 120 seconds. Subsequently, after sonication, once the light energy is stable (usually less than a minute), the dispersed sample is measured again.

[0114] In one embodiment or in combination with any of the embodiments mentioned herein, the CE microparticles have a D10 particle size of 0.5 to 20, 0.5 to 15, 0.5 to 12, 0.5 to 10, 0.5 to 5, 0.5 to 4, 0.5 to 3, 0.5 to 2, 0.5 to 1, 1 to 20, 1 to 15, 1 to 12, 1 to 5, 1 to 3, 2 to 20, 2 to 10, 2 to 5, 3 to 20, 3 to 15, 3 to 10, 4 to 20, 4 to 15, 4 to 10, 5 to 20, 5 to 15, 5 to 10, 10 to 20, or 10 to 15 microns. For example, the CE microparticles can 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, or 20 microns.

[0115] As used herein, the term "D10" means that 10% of the microparticles, based on volume, have a maximum dimension less than or equal to the noted value (e.g., 10 microns). To ensure that a representative D10 value is obtained, the sample size of the microparticles should be at least 0.5 grams. The microparticle sample size is then dispersed and mixed in 1.5 ounces of isopropyl alcohol or an aqueous surfactant solution (1 drop of 5% v / v CO-630 surfactant). The test of D10 is performed by laser diffraction and computer algorithms using the Mie theory for generating particle size distribution. A suitable particle size analyzer for determining D10 values ​​is the Malvern Mastersizer 3000 from Malvern Panalytical. When using the Malvern Mastersizer, the obscuration can be set between 2% and 5%, and the sample measurement time for both red and blue light measurements is set to three seconds. Add the dispersed sample until the desired obscuration is reached (about 4%) and then measure. After the first measurement, the sample is ultrasonically treated for 120 seconds at 50% power. Subsequently, after ultrasonic treatment, once the light energy is stable (usually less than one minute), the dispersed sample is measured again.

[0116] In one embodiment or in combination with any of the embodiments mentioned herein, the CE microparticles have a range of 1 to 100, 1 to 80, 1 to 70, 1 to 60, 1 to 50, 1 to 40, 1 to 35, 1 to 30, 1 to 25, 1 to 20, 1 to 15, 1 to 10, 5 to 100, 5 to 80, 5 to 70, 5 to 60, 5 to 50, 5 to 40, 5 to 35, 5 to 30, 5 to 25, 5 to 20, 5 to 15, 5 to 10, 10 to 100, 10 to 80, 10 to 70, 10 to 60, 10 to 50, 10 to 40, 10 to 35, 10 to 30, 10 to 25, 10 to 20, 10 to 15 30-100, 30-80, 30-70, 30-60, 30-50, 30-40, 30-35, 25-30, 30-100, 30-80, 30-70, 30-60, 30-50, 30-40, 30-35, 25-30, 30-100, 30-80, 30-70, 30-60, 30-50, 30-40, 30-35, 25-30, 30-100, 30-80, 30-70, 30-60, 30-50, 30-40, 30-35, For example, the CE microparticles 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.

[0117] As used herein, the term "D90" means that 90% of the microparticles, based on volume, have a maximum dimension less than or equal to the noted value (e.g., 10 microns). To ensure that a representative D90 value is obtained, the sample size of the microparticles should be at least 0.5 grams. The microparticle sample size is then dispersed and mixed in 1.5 ounces of isopropyl alcohol or an aqueous surfactant solution (1 drop of 5% v / v CO-630 surfactant). The test of D90 is performed by laser diffraction and computer algorithms using the Mie theory for generating particle size distribution. A suitable particle size analyzer for determining D90 values ​​is the Malvern Mastersizer 3000 from Malvern Panalytical. When using the Malvern Mastersizer, the obscuration can be set between 2% and 5%, and the sample measurement time for both red and blue light measurements is set to three seconds. Add the dispersed sample until the desired obscuration is reached (about 4%) and then measure. After the first measurement, the sample is ultrasonically treated for 120 seconds at 50% power. Subsequently, after ultrasonic treatment, once the light energy is stable (usually less than one minute), the dispersed sample is measured again.

[0118] In one embodiment or in combination with any of the embodiments mentioned herein, the CE microparticles have a range of 1 to 100, 1 to 80, 1 to 70, 1 to 60, 1 to 50, 1 to 40, 1 to 35, 1 to 30, 1 to 25, 1 to 20, 1 to 15, 1 to 10, 5 to 100, 5 to 80, 5 to 70, 5 to 60, 5 to 50, 5 to 40, 5 to 35, 5 to 30, 5 to 25, 5 to 20, 5 to 15, 5 to 10, 10 to 100, 10 to 80, 10 to 70, 10 to 60, 10 to 50, 10 to 40, 10 to 35, 10 to 30, 10 to 25, 10 to 20, 10 to 1 30-100, 30-80, 30-70, 30-60, 30-50, 30-40, 30-35, 25-30, 30-100, 30-80, 30-70, 30-60, 30-50, 30-40, 30-35, 25-30, 30-100, 30-80, 30-70, 30-60, 30-50, 30-40, 30-35, 25-30, 30-100, 30-80, 30-70, 30-60, 30-50, 30-40, or 30-35 microns. For example, the CE microparticles 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.

[0119] As used herein, the term "D100" means that 100% of the microparticles, on a volume basis, have a maximum dimension less than or equal to the noted value (e.g., 10 microns). To ensure that a representative D100 value is obtained, the sample size of the microparticles should be at least 0.5 grams. The microparticle sample size is then dispersed and mixed in 1.5 ounces of isopropyl alcohol or an aqueous surfactant solution (1 drop of 5% v / v CO-630 surfactant). The test of D100 is performed by laser diffraction and computer algorithms using the Mie theory for generating particle size distribution. A suitable particle size analyzer for determining the D100 value is the Malvern Mastersizer 3000 from Malvern Panalytical. When using the Malvern Mastersizer, the obscuration can be set between 2% and 5%, and the sample measurement time for both red and blue light measurements is set to three seconds. Add the dispersed sample until the desired obscuration (about 4%) is reached and then measure. After the first measurement, the sample is ultrasonically treated for 120 seconds at 50% power. Subsequently, after ultrasonic treatment, once the light energy is stable (usually less than one minute), the dispersed sample is measured again.

[0120] In one embodiment or in combination with any of the embodiments mentioned herein, the CE microparticles exhibit a biodegradability of at least 50%, 55%, 60%, 65%, 70%, 75%, 80% or 85% at 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.

[0121] In one embodiment or in combination with any of the embodiments mentioned herein, the CE microparticles exhibit an oil absorption of at least 0.5, 0.6, 0.7 or 0.8 g / g according to ASTM D281 using olive oil instead of castor oil.

[0122] Oil absorption is determined according to a modification of the ASTM D281 standard test method for determining oil absorption of micropowders. In the modified method, a known amount of micropowder (about 0.20 g) is weighed in a glass vial and olive oil is added drop by drop to the micropowder using a pipette. After each addition of two drops of olive oil, the powder is thoroughly mixed with the oil. The test is complete when a certain amount of oil is blended with the powder to produce a very hard, putty-like paste that will not break and separate. The dropper bottle containing the oil is then weighed to determine the amount of oil added to the powder.

[0123] The oil absorption capacity was calculated according to the following formula:

[0124] Oil absorption (g / g) = A – B / W,

[0125] Where A = initial weight of the dropper bottle with oil, B = final weight of the dropper bottle with oil, and W = weight of the sample in grams. The experiment was performed under the same conditions and was repeated at least twice more. The oil absorption was determined from the average of the results of the experiments.

[0126] In one embodiment or in combination with any of the embodiments mentioned herein, the CE microparticles exhibit a unimodal particle size distribution with 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 1.4, and / or less than 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 1.5. In certain embodiments, the CE microparticles exhibit a unimodal particle size distribution having a span of 1.0 to 3.0, 1.0 to 2.5, 1.0 to 2.0, 1.0 to 1.8, 1.0 to 1.6, 1.2 to 3.0, 1.2 to 2.5, 1.2 to 2.0, 1.2 to 1.8, 1.2 to 1.6, 1.3 to 3.0, 1.3 to 2.5, 1.3 to 2.0, 1.3 to 1.8, or 1.3 to 1.6. As used herein, "unimodal particle size distribution" refers to a particle size distribution of a material having only a single significant particle size distribution peak. This is in contrast to a multimodal particle size distribution having two or more particle size distribution peaks. The "span" of a unimodal peak can be measured using the D10, D50, and D90 values ​​of the particles using the following formula:

[0127] (D x (90)-D x (10)) / D x (50),

[0128] Where "x" is the specified granularity.

[0129] In one embodiment or in combination with any embodiment mentioned herein, the CE microparticles have a polydispersity index less than 0.8, 0.7, 0.6, 0.5, 0.4 or 0.3 and a sphericity less than 70%, 65%, 60%, 55%, 50%, 45%, 40%, 35% or 30%.

[0130] The average sphericity is determined by: (1) obtaining a secondary emission / ETD detector scanning electron microscopy (SEM) image of a representative sample of at least 40 particles, (2) on the SEM image, selecting a square sample window centered on the center of the SEM that contains exactly 30 particles with the entire peripheral boundary of the particle clearly visible (i.e., not obscured), (3) measuring the maximum and minimum diameters of the 30 clearly visible particles in the sample window (each diameter extends through the center of mass of the particle and is not necessarily perpendicular to each other), (4) for each of the 30 particles, dividing the minimum diameter by the maximum diameter and multiplying the result by 100% to obtain the sphericity of 30 individual particles, and (5) averaging the sphericity of the 30 individual particles to obtain the average sphericity.

[0131] In one embodiment or in combination with any of the embodiments mentioned herein, the CE microparticles have a butyric acid content of less than 500, 400, 300, 200, 100, 50, 20, 10, 7.5, 5, 2.5 or 1 ppmw.

[0132] In one embodiment or in combination with any of the embodiments mentioned herein, the CE microparticles have an acetic acid content of less than 500, 400, 300, 200, 100, 50, 20, 10, 7.5, 5, 2.5 or 1 ppmw.

[0133] In one embodiment or in combination with any of the embodiments mentioned herein, the CE microparticles have a propionic acid content of less than 500, 400, 300, 200, 100, 50, 20, 10, 7.5, 5, 2.5 or 1 ppmw.

[0134] The butyric, acetic, and propionic acid contents of CE microparticles can be measured by gas chromatography ("GC"). Under one GC method, the butyric, acetic, and propionic acid contents can be measured by adding approximately 100 mg of CE microparticles to a tared 4 dram vial followed by the addition of an internal standard solution containing nonane in a 90:10 mixture of dichloromethane / methanol. A magnetic stir bar is placed in the vial and the sample is stirred for two hours. After stirring, 8.0 mL of n-heptane is added dropwise to precipitate the polymer and the sample is then vortexed. Approximately 100 mg of the supernatant is transferred to a GC vial along 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 chromatographed on a 100% dimethylpolysiloxane column and a 14% cyanopropyl-phenyl-methylpolysiloxane column simultaneously using a programmed temperature method and flame ionization detection. Alternatively, a second GC method involves preparing the sample by adding approximately 30 mg of CE microparticles to a tared GC vial, followed by the addition of 200 μL of an internal standard solution containing decane in pyridine and 1.0 mL of BSTFA. The vial is heated at 80° C. for 30 minutes and then cooled to room temperature before injection. The sample is then chromatographed on a 100% dimethylpolysiloxane column and a 6% cyanopropyl-phenyl-methylpolysiloxane column simultaneously using a temperature programmed method and flame ionization detection.

[0135] In one embodiment or in combination with any of the embodiments mentioned 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 method. First, the sample to be tested is added to a titration cell and dissolved in a solvent to reach a total volume of 70 mL. For comparison, a solvent blank is also prepared. The sample and blank are then titrated with 0.05N potassium hydroxide in methanol using an automatic titrator equipped with a combined glass potentiometric electrode. The acid value is calculated based on the sample weight and the KOH consumed in the sample minus the KOH consumed in the blank.

[0136] In one embodiment or in combination with any of the embodiments mentioned herein, the CE microparticles 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% by weight of the mixed cellulose ester of the first, second and / or third aspect (including any classes or subclasses of these aspects). In addition, or in the alternative, the CE microparticles 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% by weight of the mixed cellulose esters of the first, second, and / or third aspects, including any classes or subclasses of these aspects. In certain embodiments, the CE microparticles may consist essentially of the mixed cellulose esters of the first, second, and / or third aspects, including any classes or subclasses of these aspects.

[0137] In one embodiment or in combination with any of the embodiments mentioned herein, the CE microparticles may contain an additional biodegradable cellulose ester other than the mixed cellulose ester of the first, second and / or third aspects. In such embodiments, this additional cellulose ester may be cellulose acetate, which 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 at 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.

[0138] In one embodiment or in combination with any of the embodiments mentioned herein, the CE microparticles may contain at least 1 wt%, 2 wt%, 3 wt%, 4 wt%, 5 wt%, 6 wt%, 7 wt%, 8 wt%, 9 wt% or 10 wt% of an additional biodegradable cellulose ester different from the mixed cellulose ester of the first, second and / or third aspects. Additionally, or in the alternative, the CE microparticles may contain less than 50 wt%, 45 wt%, 40 wt%, 35 wt%, 30 wt%, 25 wt%, 20 wt%, 15 wt%, 10 wt% or 5 wt% of an additional biodegradable cellulose ester different from the mixed cellulose ester of the first, second and / or third aspects.

[0139] In one embodiment or in combination with any of the embodiments mentioned herein, the CE microparticles have a particle size 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 .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 8.0m2 / g, and / or not more than 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 2 The average BET surface area of ​​​​the sample is 0.5-1 grams at 60 ° C overnight. The measurement method includes the following steps: (1) degassing 0.5-1 grams of sample at 60 ° C overnight; (2) collecting the sample mass by the weight difference between the empty sample tube and the sample tube filled with sample after degassing; (3) performing specific surface area analysis using krypton adsorption at 77K; and (4) collecting 7 relative pressures from 0.06 to 0.20 and fitting them for BET specific surface area analysis. The amount of sample depends on the specific needs and the moisture level in the sample.

[0140] In one embodiment or in combination with any of the embodiments mentioned herein, the CE microparticles have a particle size of 0.2 to 0.3 g / m 3 Bulk density within the range.

[0141] In one embodiment or in combination with any of the embodiments mentioned herein, the CE microparticles have an average sphericity of at least 20%, 30%, 40%, 50% or 60% and / or no more than 90%, 80%, 70%, 60% or 50%.

[0142] In one embodiment or in combination with any of the embodiments mentioned herein, the CE microparticles have an average smoothness of at least 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, 95%, 95%, 97%, 98% or 99% and / or no more than 99%, 95%, 90%, 80%, 70%, 60%, 50%, 40%, 30%, 20% or 10%.

[0143] The average smoothness is determined by: (1) obtaining a secondary emission / EDT detector scanning electron microscopy (SEM) image of a representative sample of at least 20 particles, (2) on the SEM, selecting a square sample window centered on the center of the SEM that contains exactly 10 particles with the entire peripheral boundary of the particle clearly visible (i.e., not obscured), (3) binarizing the sample window by manual binarization, with upper and lower thresholds selected to match the exact shape of the darker area of ​​the particle, (4) for each of the 10 particles, selecting a square window at or near the center of the particle with a length and width of approximately 1 / 3 of the particle diameter (before the particle is binarized), (5) dividing the area of ​​the dark area in the square window by the total area of ​​the square window and multiplying the result by 100% to obtain the smoothness of the 10 individual particles, and (5) averaging the 10 individual particle smoothnesses to obtain the average smoothness.

[0144] In one embodiment or in combination with any of the embodiments mentioned herein, the CE microparticles have a moisture content that is at least 0.1 wt%, 0.25 wt%, 0.5 wt%, 1 wt%, 2 wt%, 4 wt%, or 5 wt% lower than the moisture content of the initial CE particles. For example, it is believed that grinding the initial CE particles in the presence of a grinding gas, such as in a jet mill 136, reduces the moisture content of the CE microparticles relative to the initial CE particles.

[0145] In one embodiment or in combination with any of the embodiments mentioned herein, the CE microparticles have a cumulative amount of surfactant of less than 100 ppmw, 75 ppmw, 50 ppmw, 25 ppmw, 10 ppmw or 5 ppmw.

[0146] In one embodiment or in combination with any of the embodiments mentioned herein, the CE microparticles have a cumulative amount of hydrocolloids of less than 100 ppmw, 75 ppmw, 50 ppmw, 25 ppmw, 10 ppmw or 5 ppmw.

[0147] In one embodiment or in combination with any of the embodiments mentioned herein, the CE microparticles have a cumulative amount of water-soluble polymers of less than 100 ppmw, 75 ppmw, 50 ppmw, 25 ppmw, 10 ppmw or 5 ppmw. As used herein, "water-soluble polymer" means that when 1 g of the polymer is dissolved in 100 g of water at 25° C., the polymer has an insoluble content of less than 50% by weight.

[0148] In one embodiment or in combination with any of the embodiments mentioned herein, the CE microparticles have a cumulative amount of surfactant, hydrocolloid and water soluble polymer of less than 100 ppmw, 75 ppmw, 50 ppmw, 25 ppmw, 10 ppmw or 5 ppmw.

[0149] In one embodiment or in combination with any of the embodiments mentioned herein, the CE microparticles 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 no more than 1.5, 1.4, 1.3, 1.2, 1.1, 1.0, 0.9, 0.8, 0.7 or 0.6 as measured by JIS Z 8807-1976.

[0150] In one embodiment or in combination with any of the embodiments mentioned herein, the CE microparticles 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 not more than 1.4, 1.3, 1.2, 1.1, 1.0, 0.9, 0.8, 0.7, 0.6 or 0.5 as measured by JIS 1201-1.

[0151] Cosmetic preparations

[0152] The CE microparticles produced by the methods disclosed herein can be used to produce various cosmetic compositions. The cosmetic composition can be produced by: (1) providing a plurality of CE microparticles; (2) combining the CE microparticles with one or more cosmetic additives to form a pre-cosmetic mixture; and (3) forming a cosmetic composition from the pre-cosmetic mixture.

[0153] In one embodiment or in combination with any other embodiment mentioned herein, the cosmetic composition may comprise at least 0.1%, 0.5%, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, or 15% by weight of CE microparticles. Additionally, or in the alternative, the cosmetic composition may comprise less than 99%, 90%, 80%, 70%, 60%, 50%, 40%, 30%, 25%, 20%, 15%, 10%, or 5% by weight of CE microparticles. For example, the cosmetic composition may comprise 0.1 wt % to 90 wt %, 0.1 wt % to 50 wt %, 0.1 wt % to 30 wt %, 0.1 wt % to 20 wt %, 0.1 wt % to 15 wt %, 0.1 wt % to 10 wt %, 0.1 wt % to 5 wt %, 1 wt % to 90 wt %, 1 wt % to 50 wt %, 1 wt % to 30 wt %, 1 wt % to 20 wt %, 1 wt % to 15 wt %, 1 wt % to 10 wt %, or 1 wt % to 5 wt % of CE microparticles.

[0154] In one embodiment or in combination with any other embodiment mentioned herein, the cosmetic composition can be a foundation, a sunscreen, a lipstick, a mascara, an eye shadow, a lotion, a dry shampoo, a liquid shampoo, a body wash, a wash, a gas conditioner, a skin moisturizer, a face cleanser, a tablet, a foot powder, a baby powder, a shaving cream or a shaving gel.

[0155] In one embodiment or in combination with any other embodiment mentioned herein, the cosmetic composition may be a loose powder, a pressed powder, a gel, an emulsion, a liquid, or an aerosol.

[0156] In one embodiment or in combination with any other embodiment mentioned herein, the cosmetic composition comprises 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 of at least one, two, three, four, or five cosmetic additives. In addition, or in an alternative, the cosmetic composition may comprise less than 99%, 95%, 90%, 85%, 80%, 75%, 70%, 65%, 60%, 55%, or 50% by weight of at least one, two, three, four, or five cosmetic additives. For example, the cosmetic composition may contain 1 wt % to 99 wt %, 1 wt % to 95 wt %, 1 wt % to 90 wt %, 1 wt % to 85 wt %, 1 wt % to 80 wt %, 5 wt % to 99 wt %, 5 wt % to 95 wt %, 5 wt % to 90 wt %, 5 wt % to 85 wt %, 10 wt % to 99 wt %, 10 wt % to 95 wt %, 10 wt % to 85 wt %, 10 wt % to 80 wt %, 15 wt % to 99 wt %, 15 wt % to 95 wt %, 15 wt % to 90 wt %, 15 wt % to 85 wt %, or 15 wt % to 80 wt % of at least one, two, three, four, or five cosmetic additives.

[0157] Generally speaking, cosmetic additives may include solvents, colorants, oils, waxes, fatty acids, alcohols, esters, hydrocarbons, silicone oils, surfactants, metal soaps, moisturizers, thickeners, UV absorbers, antioxidants, oil absorbers, exfoliants, water, or a combination thereof.

[0158] In one embodiment or in combination with any other embodiment mentioned herein, the colorant comprises a pigment (eg, an organic pigment and / or an inorganic pigment) and / or a dye.

[0159] In one embodiment or in combination with any other embodiment mentioned herein, the oil comprises triglycine, soybean oil, cocoa butter, palm oil, palm kernel oil, hardened oil and / or hardened castor oil.

[0160] In one embodiment or in combination with any other embodiments mentioned herein, the wax comprises carnauba wax, candelilla, lanolin, lanolin, candelilla wax, cotton wax, montan wax, kapok wax, lanolin acetate, lanolin and / or lanolin fatty acid isopropyl ester.

[0161] In one embodiment or in combination with any other embodiments mentioned herein, the fatty acid comprises 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.

[0162] In one embodiment or in combination with any other embodiments mentioned herein, the alcohol comprises cetyl alcohol, stearyl alcohol, isostearyl alcohol, 2-octyldodecanol, lauryl alcohol, behenyl alcohol, myristyl alcohol, oleyl alcohol, and / or cetearyl alcohol.

[0163] In one embodiment or in combination with any other embodiment mentioned herein, the esters include isopropyl myristate, 2-octyldodecyl myristate, cetyl 2-ethylhexanoate, diisostearyl malate, tripropylene glycol dipivalate, isononyl isononanoate, isotridecyl isononanoate, isotoridecyl isononanoate, isononanoate), cetyl octanoate, isocetyl palmitate, butyl stearate, hexyl laurate, myristyl myristate, decyl oleate, hexyl decyl dimethyl octanoate, cetyl lactate, myristyl lactate, lanolin acetate, isocetyl stearate, isocetyl isostearate, cholesterol 12-hydroxystearate, ethylene glycol di-2-ethylhexanoate, dipentaerythritol fatty acid ester, N-alkyl glycol monoisostearate, neopentyl glycol dicaprate, di-2-heptyl undecanoate glyceryl, trimethyl propane tri-2-ethylhexanoate, triisostearate trimethylolpropane triol ester, pentaerythritol tetra-2-ethylhexanoate, tri-2-ethylhexanoin, tricaprylin, triisopalmitin, trimethylolpropane triisostearate, ethylhexyl palmitate, trimyristin, tri-2-heptylundecanoic acid glyceryl, castor oil fatty acid methyl ester, oleyl oleate, acetylated glycerol, 2-heptylundecanoic acid, diisobutyl adipate, hexyldecyl palmitate N-lauroyl-L-glutamate, hexyldecyl adipate, diisopropyl sebacate, ethylhexyl succinate and / or triethyl citrate.

[0164] In one embodiment or in combination with any other embodiments mentioned herein, the hydrocarbon comprises paraffin, petrolatum, and / or microcrystalline wax.

[0165] In one embodiment or in combination with any other embodiment mentioned herein, the surfactant comprises an anionic surfactant, a cationic surfactant and / or a nonionic surfactant.

[0166] In one embodiment or in combination with any other embodiment mentioned herein, the thickening agent comprises guar gum, pectin, starch, gelatin, collagen, cellulose derivatives and / or mannan.

[0167] Example

[0168] abbreviation

[0169] Ex is an example; DS is the average degree of substitution; DS OH DS is the average degree of substitution of hydroxyl groups; Ac DS is the average degree of substitution of acetyl groups; Bu is the average degree of substitution of butyryl groups; M w is the weight average molecular weight; Pr 2 O is propionic anhydride; PrOH is propionic acid; g is grams, ℃ is degrees Celsius; Ac 2 O is acetic anhydride; min is minute; AcOH is acetic acid; Mg(OAc) 2 is magnesium acetate; OAc is acetate or ester; rt is room temperature; soln is solution; kg is kilogram.

[0170] Cellulose acetate butyrate (1)(DS Ac =2.23, DS Bu =0.22, DS OH =0.55M w =50,000–90,000)

[0171] A mixture of cellulose and acid [cellulose (5.1 parts) and AcOH (20.6 parts)] was added to a stirred reactor and then soaked without heating. The mixture was heated to 55°C. A certain amount of sulfuric acid was added and the reactor was cooled to 30°C. Subsequently, AcOH was added. 2 O(11 parts) and Bu 2 O (7.1 parts) and the mixture was cooled to about 9°C with stirring. Additional sulfuric acid was added to a total of 0.8 parts and the resulting reaction mixture was warmed to 50°C until the acylation was complete and the desired molecular weight was reached. To this reaction mixture were added AcOH (23.3 parts) and H 2 The mixture was then stirred at 68°C for 720 min, but Mg(OAc) was added after 80 min.2 (0.77 parts), BuOH (8.7 parts) and H 2 O (3.4 parts). After the entire time, Mg(OAc) 2 (1.1 parts), BuOH (1.9 parts) and H 2 The mixture was completely neutralized by adding a solution of 1,2-dihydro-1,4-dihydro-2-nitropropene (6.1 parts) ...

[0172] Degree of substitution

[0173] The degree of substitution of substituents on the main chain of cellulose esters was calculated using proton nuclear magnetic resonance spectroscopy. Gel permeation chromatography was performed on cellulose esters in stabilized tetrahydrofuran. The instrument was an Agilent 1260, which consisted 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 at 28°C, and a refractive index detector at 28°C. The column set consisted of an Agilent PLgel 5 micron guard column, Mixed-C, and Oligopore in series. The system was calibrated with monodisperse polystyrene standards with a molecular weight range of about 4 million to 162. The sample was prepared as follows: approximately 25 mg of sample was weighed in 10 ml of solvent with the addition of 10 microliters of toluene to be used as a flow rate marker, a stirring bar was added to an 8-dram screw cap vial, and stirred until dissolved.

[0174] Molecular weight

[0175] Molecular weight is determined by gel permeation chromatography. Gel permeation chromatography is performed on cellulose esters in stabilized tetrahydrofuran. The instrument is an Agilent 1260, which consists 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 at 28°C, and a refractive index detector at 28°C. The column set consists of an Agilent PLgel 5 micron guard column, Mixed-C, and Oligopore in series. The system is calibrated with monodisperse polystyrene standards with a molecular weight range of about 4 million to 162. The sample is prepared as follows: weigh about 25 mg of sample in 10 ml of solvent with the addition of 10 microliters of toluene to be used as a flow rate marker, add a stirring bar to an 8-dram screw cap vial, and stir until dissolved.

[0176] By adopting the procedure used to prepare cellulose acetate butyrate 1, the following cellulose esters in Table 1 were prepared.

[0177] Table 1. Preparation conditions of Examples 2-5.

[0178]

[0179] Table 2 provides the properties of the cellulose esters prepared above.

[0180] Table 2. Degree of substitution and molecular weight of Examples 2-5.

[0181] Example <![CDATA[DS Ac ]]> <![CDATA[DS Bu ]]> Total DS <![CDATA[DS OH ]]> <![CDATA[M w (Yes)]]> 2 1.99 0.2 2.19 0.81 72208 3 2.23 0.22 1.96 0.55 70266 4 2.08 0.21 2.24 0.7 68278 5 1.86 0.2 2.14 0.92 78174

[0182] Jet grinding

[0183] There are a variety of jet milling configurations that can be used to reduce the size of particles. Such configurations are discussed in A. Chamayou and J. A. Dodds, Air Jet Milling, Handbook of Powder Technology, Vol. 12, Chapter 8, 2007 ("Chamayou"). FIG. 7 of Chamayou provides an example of a fluidized bed opposed jet mill that can be used to reduce the size of the cellulose ester particles described in Table 3 below. The jet milling method is used to reduce the average particle size of cellulose ester from 300-900 μm to about 10 μm. The operation of the fluidized bed opposed jet mill is as follows: the cellulose ester is placed in a hopper and is usually introduced into the top of the grinder ("feeding (FEEDIN)") through a double valve arrangement (or by a syringe). The cellulose ester particles fall to the bottom of the grinder under gravity, where they are entrained in one of three high-pressure air streams that are geometrically oriented toward each other, thereby forming a so-called "crushing zone". In the crushing zone, the size of the cellulose ester particles is subjected to size reduction via collisions between particles. The particles that have undergone size reduction are then carried upward by mass transport in a vertical air flow (fluidized bed), which ultimately carries them to a classifier. The classifier enables particles below the desired minimum size to be removed from the mill ("FINE OUT"). Particles that exceed the maximum size will be excluded from the classifier and sent back to the fluidized bed, ultimately falling back into the comminution zone for further size reduction. Particles that fall within the desired size range are ejected from the classifier into an appropriate product container. There are many control parameters for optimizing productivity, particle size, and particle size distribution shape, including but not necessarily limited to classifier rotor speed, air nozzle pressure, and bed level.

[0184] Moisture determination

[0185] Moisture levels were determined using a Torbal moisture balance using 1 gram of material and heating the material to 115°F.

[0186] Refractive index measurement

[0187] Cellulose ester films were prepared by making a dopant using 12 wt% solid in a dichloromethane / methanol solution (9:1) or a dichloromethane / ethanol solution (9:1) to determine the refractive index of cellulose ester. The film was cast from the dopant onto a glass substrate and evenly spread onto the glass substrate using a casting knife. The wet dopant on the glass substrate was covered and the solvent was allowed to evaporate slowly for 45 minutes while being covered. The film was then allowed to evaporate for 15 minutes without a cover. The film was peeled off from the substrate and placed between two sheets of paper and placed aside with a weight to ensure that the film was flat (about 2 hours). The film was then placed between metal frames and annealed in an oven set to 100°C for 10 minutes and in another oven set to 120°C for 10 minutes. The resulting film was used to measure the refractive index using Metricon (prism coupling method) at a wavelength of 589nm.

[0188] Young's modulus

[0189] Films were prepared as disclosed in the procedure for determining the refractive index. The films were cut into 6 inch x 0.5 inch specimens. Young's modulus was determined by testing 5 specimens. Each specimen was tested in a tensile mode at 0.2 inches / minute (maximum strain of 1.6%) and then tested at 2 inches / minute until the film broke.

[0190] OECD 301F Test Description

[0191] In this experiment, a measured volume of mineral culture medium is inoculated with a known concentration of the test substance, which serves as a nominal source of organic carbon. The medium is placed in a closed flask and stirred at a constant temperature (within +1°C or closer) for up to 60 days.

[0192] Oxygen consumption can be determined using one of two methods: either by measuring the amount of oxygen required to maintain a constant amount of gas in the respirometer flask (generated electrolytically), or by monitoring changes in volume or pressure (or a combination of both) in the instrument.

[0193] Any carbon dioxide produced during the process is absorbed using potassium hydroxide solution or another suitable absorbent. The amount of oxygen utilized by the microbial population during biodegradation of the test substance is calculated by subtracting the oxygen uptake of a blank inoculum (performed in parallel). This value is expressed as a percentage of the theoretical oxygen demand (ThOD) or, less ideally, the chemical oxygen demand (COD).

[0194]

[0195] Additional CE microparticles made by jet milling are provided in Table 4. These particles were demonstrated to be greater than 60% biodegradable under the OECD 301F biodegradation test.

[0196] Table 4.

[0197]

Claims

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

2. The method according to claim 1, wherein the milling of step (b) is performed by jet milling or bead milling the initial CE particles.

3. The method according to any one of claims 1-2, further comprising subjecting the initial CE particles to size reduction before carrying out the grinding of step (b).

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

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

6. The method according to any one of claims 1 to 5, further comprising providing compressed gas for at least one of the milling of step (b), or for conveying the initial CE particles to the milling of step (b).

7. The method according to claim 6, further comprising: supplying a first portion of the compressed gas for use in the grinding of step (b); as well as A second portion of the compressed gas is supplied for conveying the initial CE particles to the grinding of step (b), wherein the first portion is supplied at a greater velocity than the second portion.

8. The method according to any one of claims 1 to 7, further comprising separating the CE microparticles produced by the milling of step (b) from a milling gas, thereby forming a CE product stream and a separated gas stream.

9. The method according to claim 8, further comprising: Said separated gas stream is recycled for use in at least one of said grindings of step (b), or for conveying said initial CE particles to said grinding of step (b).

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

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

12. The method according to any one of claims 1-11, further comprising collecting a coarse product fraction and a fine product fraction of the CE microparticles at separate product packaging stations.

13. A system for producing cellulose ester (CE) microparticles, the system comprising: The source of initial CE particles; Compressors for producing compressed gases; a jet mill for receiving said initial CE particles and subjecting them to size reduction into CE microparticles, wherein said jet mill is supplied with a first portion of said compressed gas from said compressor; and a feed system for supplying the initial CE particles to the jet mill, wherein the feed system is supplied with the second portion of the compressed gas from the compressor.

14. The system of claim 13, further comprising a separator for receiving the CE particles entrained in the milling gas from the jet mill, wherein the separator separates the CE particles from the milling gas to form a CE product stream and a separated gas stream.

15. The system of claim 14, wherein the separator comprises a filter for separating the CE particles from the milling gas.

16. The system of any one of claims 14-15, wherein the compressor compresses the separated gas stream to be provided 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 13-16, further comprising at least one product packaging station for collecting the CE microparticles.

18. The system of any one of claims 13-17, further comprising a splitter located downstream of the compressor, the splitter for splitting the compressed gas into the first and second portions.

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

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

21. The system of any one of claims 13-20, further comprising a mechanical grinder located upstream of the jet mill, the mechanical grinder being used to pre-grind the initial CE particles before they are provided to the jet mill.

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

23. Biodegradable cellulose ester (CE) particles comprising at least one CE, wherein the CE particles have a D50 particle size in the range of 0.5 to 50 microns, wherein the CE particles exhibit at least 50% biodegradability at 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 surfactant, hydrocolloid and water-soluble polymer present in the CE particles is less than 100 ppmw.

24. The method, system and / or product of any one of claims 1-23, wherein the CE microparticles exhibit an oil absorption of at least 0.5, 0.6, 0.7 or 0.8 g / g according to ASTM D281 using olive oil instead of castor oil.

25. The method, system and / or product of any one of claims 1-24, wherein the CE microparticles exhibit a unimodal particle size distribution spanning the range of 1.0 to 1.

5.

26. The method, system and / or product of any one of claims 1-25, wherein the CE comprises at least one of cellulose acetate, cellulose acetate butyrate, or cellulose acetate propionate, and wherein the CE has an average degree of substitution ("DS") of hydroxyl substituents in the range of 0.6 to 2.8 OH ”).

27. The method, system and / or product of any one of claims 1-26, wherein the CE microparticles have a polydispersity index of less than 0.8 and a sphericity of less than 70%.

28. The method, system and / or product of any one of claims 1-27, wherein the CE particles have a m / s of at least 0.9, or 1.0, or 1.1, or 1.2, or 1.3, or 1.4, or 1.

5. 2 / g, and / or not more than 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 The average BET surface area of ​​​​the sample is 2.5477 square meters.

29. The method, system and / or product according to any one of claims 1 to 28, wherein the CE particles have a particle size of 0.2 to 0.3 g / m 3 The bulk density is within the range of .

30. The method, system and / or product of any one of claims 1-29, wherein the CE particles have an average smoothness of at least 10%, or 20%, or 30%, or 40%, or 50%, or 60%, or 70%, or 80%, or 90%, or 95%, or 95%, or 97%, or 98%, or 99%, and / or no more than 99%, or 95%, or 90%, or 80%, or 70%, or 60%, or 50%, or 40%, or 30%, or 20%, or 10%.

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