Cellulose ester compositions with recycled cellulose ester

Abstract

A melt composition comprising a virgin cellulose ester feedstock and at least ten percent (10%) recycled cellulose ester material, as measured based on the total weight of the melt composition. The virgin cellulose ester feedstock is a formulated feedstock comprising a cellulose ester and a plasticizer. The melt composition has a molecular weight (Mw) within seventy-five percent (75%) of a molecular weight (Mw) of the virgin cellulose ester feedstock.

Description

CELLULOSE ESTER COMPOSITIONS WITH RECYCLED CELLULOSE ESTERBACKGROUND OF THE INVENTION

[0001] Many plastic articles, such as rigid cutlery and foamed foodpackaging articles, are single-use items that are intended to be disposed of after use. However, many commonly used plastics, such as polystyrene, are neither compostable nor biodegradable. Moreover, some municipalities, states, and countries have enacted, or are considering enacting, bans on the use of polystyrene-based materials. Thus, it is desirable to find alternative materials for use in plastic articles, as well as viable compositions, methods, and systems for producing such articles.

[0002] In particular, there is a need for a bio-based or biodegradable material that has physical properties that can compete with traditional plastics in a range of applications. Cellulose esters, such as cellulose acetate, comprise bio-based and biodegradable resins, and such cellulose ester compositions have been used for a variety of melt-processed articles.However, it would provide a further environmental and economic benefit if cellulose ester-based articles (or portions thereof) could be recycled into new resins and resulting articles to further enhance renewability and to reduce waste. Unfortunately, although cellulose ester-based articles (or portions thereof) are generally biodegradable, the cellulose ester compositions previously used in cellulose ester-based articles are not generally suitable for recycling. For instance, recycling previously used cellulose ester materials would commonly result in an unwanted increase in polymer degradation and / or a decrease in color stability of the resulting polymer resins and articles.SUMMARY OF THE INVENTION

[0003] In one aspect, there is provided a melt composition comprising a virgin cellulose ester feedstock and at least ten percent (10%) recycled cellulose ester material, as measured based on the total weight of the melt composition. The virgin cellulose ester feedstock is a formulated feedstockcomprising a cellulose ester and a plasticizer. The recycled cellulose ester material can comprise one or more of the following: i) cellulose ester having a molecular weight (Mw) less than the Mw of the virgin cellulose ester in the feedstock; ii) a plasticizer content lower than the plasticizer content of the feedstock; and / or iii) a glass transition temperature (Tg) higher than the Tg of the feedstock. The melt composition can have one or more of the following: a) a molecular weight (Mw) within seventy-five percent (75%) of a molecular weight (Mw) of the virgin cellulose ester feedstock; b) a plasticizer content within eighty-five percent (85%) of a plasticizer content of the virgin cellulose ester feedstock; and / or c) a glass transition temperature (Tg) that is equal to or higher than a glass transition temperature (Tg) of the virgin cellulose ester feedstock.

[0004] In one embodiment or in combination with any other embodiment mentioned herein, there is provided a melt composition comprising a virgin cellulose ester feedstock and at least ten percent (10%) recycled cellulose ester material, as measured based on the total weight of the melt composition. The virgin cellulose ester feedstock is a formulated feedstock comprising a cellulose ester and a plasticizer. The melt composition has a molecular weight (Mw) within seventy-five percent (75%) of a molecular weight (Mw) of the virgin cellulose ester feedstock.

[0005] In another embodiment or in combination with any other embodiment mentioned herein, there is provided a melt composition comprising a virgin cellulose ester feedstock and at least ten percent (10%) recycled cellulose ester material, as measured based on the total weight of the melt composition. The virgin cellulose ester feedstock is a formulated feedstock comprising a cellulose ester and a plasticizer. The melt composition has a plasticizer content within eighty-five percent (85%) of a plasticizer content of the virgin cellulose ester feedstock.

[0006] In another embodiment or in combination with any other embodiment mentioned herein, there is provided a melt composition comprising a virgin cellulose ester feedstock and at least ten percent (10%) recycled cellulose ester material, as measured based on the total weight ofthe melt composition. The virgin cellulose ester feedstock is a formulated feedstock comprising a cellulose ester and a plasticizer. The melt composition has a glass transition temperature (Tg) that is equal to or higher than a glass transition temperature (Tg) of the virgin cellulose ester material.

[0007] In another embodiment or in combination with any other embodiment mentioned herein, there is provided a process for forming a cellulose ester article. The process comprises one step of obtaining cellulose ester scrap material. An additional step includes regrinding the cellulose ester scrap material to form a reground scrap material that is particulated. An additional step includes removing moisture from the reground scrap material. An additional step includes obtaining cellulose ester virgin feedstock, with the virgin feedstock being a formulated feedstock comprising a cellulose ester and a plasticizer. An additional step includes removing moisture from the virgin feedstock. A further step includes combining the reground scrap material and the virgin feedstock to form a cellulose ester melt composition.

[0008] In another embodiment or in combination with any other embodiment mentioned herein, there is provided a melt composition comprising: a virgin cellulose ester feedstock, with the virgin cellulose ester feedstock being a formulated feedstock comprising a cellulose ester and a plasticizer. The melt composition further comprises at least ten percent (10%) recycled cellulose ester material, as measured based on the total weight of the melt composition. When the melt composition is formed into a test film according to the Film Forming Procedure described in the specification, the test film exhibits a AE color difference of less than 3 units with respect to a control film formed according to the Film Forming Procedure described in the specification, with the control film formed from virgin cellulose ester feedstock and no recycled cellulose ester material. The AE color difference being defined by the equation:AE =[(Aa*)2+(Ab*)2+(AL*)2]1 / 2, with a*, b*, and L* being CIE 1976 color space values measured according to ASTM 2244.BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure (FIG.) 1 is a schematic diagram illustrating a biodegradable article forming process according to embodiments of the present invention, particularly configured to form foam articles;

[0010] FIG. 2 is a schematic diagram illustrating another biodegradable article forming process according to embodiments of the present invention, particularly configured to form foam articles;

[0011] FIG. 3 is a schematic diagram illustrating another biodegradable article forming process according to embodiments of the present invention, particularly configured to form rigid articles;

[0012] FIG. 4 is a schematic diagram illustrating an extrusion section that may be used in the foam article forming processes of FIGS. 1 and / or 2, according to embodiments of the present invention;

[0013] FIG. 5 is a schematic diagram illustrating another extrusion section that may be used in the foam article forming process of FIGS. 1 and 2, according to embodiments of the present invention;

[0014] FIG. 6 is a schematic diagram illustrating a foam sheet forming section that may be used in the foam article forming processes of FIGS. 1 and / or 2, according to embodiments of the present invention;

[0015] FIG. 7 is a schematic diagram illustrating an extrusion section that may be used in the rigid article forming processes of FIG. 3, according to embodiments of the present invention;

[0016] FIG. 8 is a schematic diagram illustrating recycling process that may be used in the foam article forming processes of FIGS. 1 and 2, according to embodiments of the present invention; and

[0017] FIG. 9 is a schematic diagram illustrating recycling process that may be used in the rigid article forming processes of FIGS. 3, according to embodiments of the present invention.DETAILED DESCRIPTION

[0018] Embodiments are generally directed to methods, systems, and compositions for forming biodegradable particulate materials (e.g., pellets), foam sheets, and / or foamed or rigid articles. Generally, such particulate materials (e.g., pellets), foam sheets, and / or foamed or rigid articles will be particularly configured to be suitable for recycling. Exemplary processes including the methods, systems, and compositions are depicted in FIGS. 1 - 9 and are described in greater detail below.Methods and Systems

[0019] As shown in FIG. 1 and FIG. 2, raw materials may be introduced to a biodegradable polymer production process, which produces a biodegradable polymer material. In one embodiment or in combination with any other embodiment mentioned herein, the biodegradable polymer material comprises one or more cellulose esters. The one or more cellulose esters may comprise cellulose acetates. In such embodiments, the raw materials may comprise a pulp, such as wood pulp and / or cotton pulp. The pulp may be a dissolving-grade pulp and / or a paper-grade pulp. The cellulose in the pulp may esterified, for example with an acetic acid, to form the biodegradable cellulose ester polymer, such as a cellulose acetate polymer.

[0020] The biodegradable polymer material may then be introduced into a compounding process, in which the biodegradable polymer material may be mixed with plasticizer, and optionally one or more other additives (e.g., stabilizers), and formed into a compounded material comprising plasticized biodegradable polymer. Other additives may also be mixed with the polymer and plasticizer. For example, as shown in FIG. 2, the other materials (additives) may include, but are not limited to, stabilizers, physical blowingagent(s), chemical blowing agent(s) (and / or precursors), nucleating agent(s), surface modifying additive(s), pigment(s), filler(s), and / or other additive(s). Mixing can be accomplished by any known mixing technique, including, but not limited to, rolling in a cylindrical container, overhead stirring, sigma blade mixing, and tumbling.

[0021] The compounding process may include a particulating process. The particulating process may generally comprise mixing the biodegradable polymer material, plasticizer, and other additive(s) to form a mixed composition and forming particulate material from the composition. In particular, the particulating process may include a pelletization process, and the particulate material may comprise a quantity of pellets. The term “compounded CE material” means cellulose ester material formed during the compounding process, which may include a mixture of cellulose ester, plasticizer, and other additives. Further such compounded CE material may be in the form of particulate material (e.g., pellets, powders, granules, fibers, etc.). It should be understood that, as used herein, the phrases “particulating” or “particulating processes” may be the same as, or may at least include, “pelletizing” or “pelletizing processes.” In some embodiments, the particulating process may include pelletizing into a water bath, pelletizing on an air-cooled belt, underwater pelletizing, solvent compounding, etc.

[0022] In one embodiment or in combination with any other embodiment mentioned herein, the plasticizer and other additive(s) may be mixed with cellulose esters in the compounding process by conventional melt compounding techniques, which involve combining the cellulose ester with plasticizer, and optionally the other additives, in a twin screw extruder with appropriate mixing elements and at appropriate temperatures and pressures to achieve a molten, homogeneously combined, cellulose ester mixture by the time the materials exit the extruder. The molten, compounded, cellulose ester mixture may then be extruded through a die with orifices that are about 2-6 mm in diameter so as to extrude a strand. This strand may then be cooled by water (e.g., via underwater pelletization) or air and cut at regular intervals to provide a uniform and desirable size and shape, referred to as “pellets” or“granules.” Although a process for forming pelletized compounded material is described herein, it will be understood that the compounded material fed to the foam sheet production process can be in any physical shape (e.g., pellets, powders, granules, fibers) in accordance with some embodiments.

[0023] The compounded CE material, which as noted above may comprise pellets of plasticized biodegradable polymer, may then be introduced into a foam sheet production process, as illustrated in FIGS. 1 and 2. The foam sheet production process may include one or more zones / steps for producing a foam sheet or film, which are described in greater detail below. Although an exemplary foam sheet production process is described herein, it should be understood that certain aspects described herein may also be applicable to rigid (i.e., non-foamed) materials and articles. For example, FIG. 3 illustrates a process by which compounded CE material is provided to a rigid article production zone to prepare rigid articles (e.g., single-use cutlery), as described in more detail below.

[0024] Returning to FIGS. 1 and 2, in one embodiment or in combination with any other embodiment mentioned herein, various additives may be introduced to one or more zones of the foam sheet production process. The additives may include, but are not limited to, stabilizers, physical blowing agent(s), chemical blowing agent(s) (and / or precursors), nucleating agent(s), surface modifying additive(s), pigment(s), filler(s), and / or other additive(s).

[0025] The foam sheet production process may generally include an extrusion section and a sheet forming section. An exemplary extrusion section is depicted in FIG. 4. As shown, the extrusion section may comprise a feed preparation zone, in which solid additives may be combined with the compounded CE material and introduced to the downstream extrusion zone. In one embodiment or in combination with any other embodiment mentioned herein, the feed preparation zone may comprise a feed hopper. Thus, the compounded CE material and the other solid additives may be deposited into the feed hopper, which directs the combined feed composition into the extrusion zone. The feed preparation zone may further comprise a mixer, in which the compounded CE material and one or more additive(s) may bemixed before being introduced to the hopper. Mixing can be accomplished by any known mixing technique, including, but not limited to, rolling in a cylindrical container, overhead stirring, sigma blade mixing, and tumbling. Exemplary solid additive(s) that can be combined with the compounded material may include chemical blowing agent(s), nucleating agent(s), surface modifying additive(s), pigment(s), filler(s), and / or other additive(s).

[0026] The combined feed composition from the feed preparation zone may then be introduction to the extrusion zone. The extrusion zone may generally comprise one or more extruders, which may include single screw and / or twin-screw extruders. Within the extruder(s), the feed composition may be introduced into an extruder barrel and conveyed, via the screw(s), through a die, which forms an extrudate from the feed composition. The composition may be heated, and at least partially melted, as it is conveyed through the extruder barrel toward the die. Thus, the term “CE melt composition” is used herein to mean the cellulose ester-based feed composition that has been melted into a flowable, molten resin via the extrusion section. Heating may be supplied by external heaters positioned along the outside of the extruder barrel. The shape of the extrudate will generally depend on the shape and size of the die head. The extrudate may be further shaped by downstream processes, as described below.

[0027] One or more additive(s) may be introduced to the CE melt resin while in the extruder. For example, one or more physical blowing agent(s) may be added to the CE melt resin by injecting the physical blowing agent into the composition being conveyed within the extruder barrel.

[0028] As depicted in FIG. 5, in one embodiment or in combination with any other embodiment mentioned herein, the extrusion zone may comprise a primary extrusion vessel and a cooling vessel. The primary extrusion vessel and cooling vessel may be separate devices or combined as a unitary apparatus. Regardless, the feed composition from the feed preparation zone is introduced into the primary extrusion vessel and at least partially melted as it is conveyed through the extruder barrel, as described above, to thereby produce the CE melt resin. The CE melt resin exiting the primary extrusionvessel may have a temperature from about 220° C to about 240° C. One or more additives, such as blowing agent(s), may be added to the CE melt resin as it is conveyed through the primary extrusion vessel.

[0029] The CE melt resin from the primary extrusion vessel is then introduced into the cooling vessel. The cooling vessel may be a secondary extrusion vessel, which operates similarly to, but at a lower temperature than, the primary extrusion vessel. Within the cooling vessel, the CE melt resin may be further mixed to provide a substantially homogenous mixture of the melted polymer and other additive(s). The CE melt resin may then be directed through the die and out of the die head to provide a cellulose ester-based extrudate, which may be further processed in the sheet forming section of the foam sheet production process. In one embodiment or in combination with any other embodiment mentioned herein, the CE melt resin exiting the die head may have a temperature of at least 150° C, at least 160° C, at least 170° C, at least 180° C, at least 190° C, at least 200° C, from about 150° C to about 220° C, and / or from about 170° C to about 200° C.

[0030] As shown in FIG. 5, one or more filtration devices may be installed within the extrusion section to filter and remove particulate matter from the CE melt resin. For example, screen changer filtration devices may be installed at the downstream end of the primary and secondary extrusion vessels, which may remove solid components from the CE melt resin before directing the CE melt resin through the die head to the sheet forming section.

[0031] The sheet forming section may include any of a variety of systems and processes for shaping the extrudate into sheets of cellulose ester material that may be used in article formation. The shape of the extrudate will generally depend on the shape of the die head, while the shape of the sheets formed in the sheet forming section can depend on the shape of the die head and other downstream processes. For example, the extrudate may have a generally flat shape, or it may be annular and subjected to further processing to form a flat sheet. In embodiments in which the die has an annular shape, the die may have a diameter from 1 to 40 cm, from 2 to 20 cm, 2 to 10 cm, and / or 3 to 8 cm. Furthermore, the thickness of the opening from whichextrudate is ejected, which is referred to herein as a “die gap,” may generally be sized from 0.1 to 6.0 mm, from 0.1 to 3.0 mm, and / or from 0.1 to 1.0 mm.

[0032] An exemplary sheet forming section is depicted in FIG. 6. As shown, the CE melt resin is extruded through an annular die and drawn over a forming mandrel. A cooling fluid (e.g., air) may be flowed across the interior and / or exterior of the extrudate to cool the extrudate material as it passes over the mandrel. For example, the cooling fluid may be blown from the mandrel toward the die to cool the interior surface of the extrudate between the die and mandrel. Additionally, or alternative, the cooling fluid may be flowed across the mandrel to cool the exterior surface of the extrudate as it passes over the mandrel.

[0033] A slicer (or slitting device) may be used to open the tubular extrudate, which allows the tubular shape to be formed into a flat sheet. For example, the tubular extrudate passing over the mandrel may be slit and drawn to a tensioning station comprising one or more rollers that flatten the extrudate and maintain a necessary amount of tension on the extrudate to continue pulling the extrudate over the mandrel. The flattened extrudate will generally be in the form of a sheet, which may then be directed to a winding station where the material may be rolled for packaging and transportation.

[0034] Referring again to FIG. 1 and FIG. 2, the foam sheets produced by the sheet production process may be used to form foam articles, which are described in greater detail below. The articles may be formed from the sheets via a thermoforming process by which the foam sheets are heated and placed over / in a mold to be shaped in the form of the requisite foam articles. Such foam articles are particularly useful in the food service industry. Exemplary articles include foam food trays. The articles may have one or more particularly advantageous properties. For example, the articles may be biodegradable and / or compostable, and / or the articles may have superior mechanical properties (e.g., strength, density, cell size, absorption, etc.). Furthermore, as described in more detail below, the articles (or portions or scrap thereof) may be recyclable.

[0035] In addition, as was discussed above with respect to FIG. 3, rigid articles (e.g., non-foam articles) may be formed from cellulose ester materials according to a process similar to that described above with respect to the foam article. Specifically, as shown in FIG. 7, compounded CE material may be mixed with other solids (e.g., additives, such as colors and fillers) and provided to an extrusion section to form a CE melt resin. Instead of passing the CE melt resin through an annular die to form a sheet, the CE melt resin may be injected into a mold, via injection molding process, to form rigid articles. Such rigid articles may include articles of various sizes and shapes, but may, in some embodiments, include single-use cutlery, such as knives, spoons, forks, etc. The articles may have one or more particularly advantageous properties. For example, the articles may be biodegradable and / or compostable, and / or the articles may have superior mechanical properties (e.g., strength, density, cell size, absorption, etc.). Furthermore, as described in more detail below, the articles (or portions or scrap thereof) may be recyclable.Compositions

[0036] The processes described above may comprise the preparation and extrusion of compositions that may be used for downstream processing to form useful articles. For example, in one embodiment or in combination with any other embodiment mentioned herein, the extrusion feed material may comprise a particulate material comprising a biodegradable polymer, a plasticizer, and optionally one or more additive(s), such as those described herein. In one embodiment or in combination with any other embodiment mentioned herein, the feed material may be combined with one or more additive(s), such as those described herein, to provide a mixed composition comprising the biodegradable polymer, the plasticizer, and the one or more additive(s). In one embodiment or in combination with any other embodiment mentioned herein, the biodegradable polymer comprises cellulose ester. Additional details of the composition components, including biodegradable polymers (e.g., cellulose esters), plasticizers, and other additives, are provided below.Cellulose Ester

[0037] The cellulose esters utilized as described herein can be any that is known in the art. Cellulose ester that can be used for embodiments herein generally comprise repeating units of the structure:1 2 2

[0038] wherein R1, R , and R are selected independently from the group consisting of hydrogen acetyl, propyl or butyl. The substitution level of the cellulose ester is usually expressed in terms of degree of substitution (DS), which is the average number of non-OH substituents per anhydroglucose unit (AGU). Generally, conventional cellulose contains three hydroxyl groups in each AGU unit that can be substituted; therefore, DS can have a value between zero and three. Native cellulose is a large polysaccharide with a degree of polymerization from 250 - 5,000 even after pulping and purification, and thus the assumption that the maximum DS is 3.0 is approximately correct. Because DS is a statistical mean value, a value of 1 does not assure that every AGU has a single substituent. In some cases, there can be unsubstituted anhydroglucose units, some with two and some with three substituents, and typically the value will be a non-integer. Total DS is defined as the average number of all of substituents per anhydroglucose unit. The degree of substitution per AGU can also refer to a particular substituent, such as, for example, hydroxyl or acetyl. In one embodiment or in combination with any other embodiment, n is an integer in a range from 25 to 250, or 25 to 200, or 25 to 150, or 25 to 100, or 25 to 75.

[0039] In one embodiment or in combination with any other embodiment, the cellulose esters have at least 2 anhydroglucose rings and can have between at least 50 and up to 5,000 anhydroglucose rings, or at least 50 andless than 150 anhydroglucose rings. The number of anhydroglucose units per molecule is defined as the degree of polymerization (DP) of the cellulose ester. In one embodiment or in combination with any other embodiment, cellulose esters can have an inherent viscosity (IV) of about 0.2 to about 3.0 deciliters / gram, or about 0.5 to about 1.8, or about 1 to about 1.5, as measured at a temperature of 25°C for a 0.25 gram sample in 100 ml of a 60 / 40 by weight solution of phenol / tetrachloroethane. In one embodiment or in combination with any other embodiment, cellulose esters useful herein can have a DS / AGU of about 1 to about 3.0 of about 2.2 to about 2.8, or 1 to less than 2.2, or 1 to less than 1 .5, and the substituting ester is acetyl.

[0040] Cellulose esters can be produced by any method known in the art. Examples of processes for producing cellulose esters are taught in Kirk- Othmer, Encyclopedia of Chemical Technology, 5th Edition, Vol. 5, Wiley- Interscience, New York (2004), pp. 394-444. Cellulose, the starting material for producing cellulose esters, can be obtained in different grades and sources such as from cotton linters, softwood pulp, hardwood pulp, corn fiber and other agricultural sources, and bacterial cellulose, among others.

[0041] One method of producing cellulose esters is esterification of the cellulose by mixing cellulose with the appropriate organic acids, acid anhydrides, and catalysts. Cellulose is then converted to a cellulose triester. Ester hydrolysis is then performed by adding a water-acid mixture to the cellulose triester, which can then be filtered to remove any gel particles or fibers. Water is then added to the mixture to precipitate the cellulose ester. The cellulose ester can then be washed with water to remove reaction byproducts followed by dewatering and drying.

[0042] The cellulose triesters to be hydrolyzed can have three acetyl substituents. These cellulose esters can be prepared by a number of methods known to those skilled in the art. For example, cellulose esters can be prepared by heterogeneous acylation of cellulose in a mixture of carboxylic acid and anhydride in the presence of a catalyst such as H2SO4. Cellulose triesters can also be prepared by the homogeneous acylation of cellulose dissolved in an appropriate solvent such as LiCI / DMAc or LiCI / NMP.

[0043] Those skilled in the art will understand that the commercial term of cellulose triesters also encompasses cellulose esters that are not completely substituted with acyl groups. For example, cellulose triacetate commercially available from Eastman Chemical Company, Kingsport, TN, U.S.A., typically has a DS from about 2.85 to about 2.99.

[0044] After esterification of the cellulose to the triester, part of the acyl substituents can be removed by hydrolysis or by alcoholysis to give a secondary cellulose ester. As noted previously, depending on the particular method employed, the distribution of the acyl substituents can be random or non-random. Secondary cellulose esters can also be prepared directly with no hydrolysis by using a limiting amount of acylating reagent. This process is particularly useful when the reaction is conducted in a solvent that will dissolve cellulose. All of these methods yield cellulose esters that are useful in this invention.

[0045] In one embodiment or in combination with any of the mentioned embodiments, the cellulose acetates are cellulose diacetates that have a polystyrene equivalent number average molecular weight (Mn) from about 10,000 to about 100,000 as measured by gel permeation chromatography (GPC) using NMP as solvent and polystyrene equivalent Mn according to ASTM D6474. In one embodiment or in combination with any other embodiment, the cellulose acetate composition comprises cellulose diacetate having a polystyrene equivalent number average molecular weights (Mn) from 10,000 to 90,000; or 10,000 to 80,000; or 10,000 to 70,000; or 10,000 to 60,000; or 10,000 to less than 60,000; or 10,000 to less than 55,000; or 10,000 to 50,000; or 10,000 to less than 50,000; or 10,000 to less than 45,000; or 10,000 to 40,000; or 10,000 to 30,000; or 20,000 to less than 60,000; or 20,000 to less than 55,000; or 20,000 to 50,000; or 20,000 to less than 50,000; or 20,000 to less than 45,000; or 20,000 to 40,000; or 20,000 to 35,000; or 20,000 to 30,000; or 30,000 to less than 60,000; or 30,000 to less than 55,000; or 30,000 to 50,000; or 30,000 to less than 50,000; or 30,000 to less than 45,000; or 30,000 to 40,000; or 30,000 to 35,000; as measured bygel permeation chromatography (GPC) using NMP as solvent and according to ASTM D6474.

[0046] The most common commercial secondary cellulose esters are prepared by initial acid catalyzed heterogeneous acylation of cellulose to form the cellulose triester. After a homogeneous solution in the corresponding carboxylic acid of the cellulose triester is obtained, the cellulose triester is then subjected to hydrolysis until the desired degree of substitution is obtained. After isolation, a random secondary cellulose ester is obtained. That is, the relative degree of substitution (RDS) at each hydroxyl is roughly equal.

[0047] The cellulose esters useful in the present invention can be prepared using techniques known in the art, and can be chosen from various types of cellulose esters, such as for example the cellulose esters that can be obtained from Eastman Chemical Company, Kingsport, TN, U.S.A., e.g., Eastman™ Cellulose Acetate CA 398-30 and Eastman™ Cellulose Acetate CA 398-10, Eastman™ CAP 485-20 cellulose acetate propionate; Eastman™ CAB 381-2 cellulose acetate butyrate.

[0048] In one embodiment or in combination with any other embodiment, the cellulose ester can be prepared by converting cellulose to a cellulose ester with reactants that are obtained from recycled materials, e.g., a recycled plastic content syngas source. In one embodiment or in combination with any other embodiment, such reactants can be cellulose reactants that include organic acids and / or acid anhydrides used in the esterification or acylation reactions of the cellulose, e.g., as discussed herein.

[0049] In one embodiment or in combination with any of the mentioned embodiments, or in combination with any of the mentioned embodiments, of the invention, a cellulose ester composition comprising at least one recycle cellulose ester is provided, wherein the cellulose ester has at least one substituent on an anhydroglucose unit (AU) derived from recycled content material, e.g., recycled plastic content syngas.

[0050] In one embodiment or in combination with any other embodiment, the cellulose ester composition comprises cellulose ester in an amount from 50 to 99 wt%, or 60 to 99 wt%, or 70 to 99 wt%, or 80 to 99 wt%, or 90 to 99wt%, 50 to 90 wt%, or 60 to 90 wt%, or 70 to 90 wt%, or 80 to 90 wt%, or 90 to 99 wt%, or 50 to 80 wt%, or 60 to 80 wt%, or 70 to 80 wt%, or 50 to 70 wt%, or 60 to 70 wt%, or 50 to 60 wt%, all based on the total weight of the cellulose ester composition. In some embodiments, the cellulose ester used herein may comprise a combination, blend, or mixture of two or more different types of cellulose esters. For example, in some embodiments, the cellulose esters used herein may be comprised of a blend of two or cellulose esters having differing DSACs; however, the blend may have a total DSAC of between 2.2 and 2.8Plasticizer

[0051] In one embodiment or in combination with any other embodiment, the cellulose ester compositions described herein can comprise at least one plasticizer. The plasticizer reduces the melt temperature, i.e. , the Tg, and / or the melt viscosity of the cellulose ester. Plasticizers for cellulose esters may include glycerol triacetate (Triacetin), glycerol diacetate (Diacetin), dibutyl terephthalate, dimethyl phthalate, diethyl phthalate, polyethylene glycol) MW 200-600, dibutyl tartrate, di-2-methoxyethyl phthalate, ethyl o- benzoylbenzoate, triethylene glycol dipropionate, 1 ,2-epoxypropylphenyl ethylene glycol, 1 ,2-epoxypropyl(m-cresyl) ethylene glycol, 1 ,2-epoxypropyl(o- cresyl) ethylene glycol, p-oxyethyl cyclohexenecarboxylate, bis(cyclohexanate) diethylene glycol, triethyl citrate, polyethylene glycol, propylene glycol, polysorbate, sucrose octaacetate, acetylated triethyl citrate, acetyl tributyl citrate, Admex, tripropionin, Scandiflex, poloxamer copolymers, polyethylene glycol succinate, diisobutyl adipate, polyvinyl pyrollidone, and glycol tribenzoate, the benzoate containing plasticizers such as the Benzoflex™ plasticizer series, poly (alkyl succinates) such as poly (butyl succinate), polyethersulfones, o-Cresyl p-toluenesulfonate, n- ethyltoluenesulfonamides, adipate based plasticizers, soybean oil epoxides such as the Paraplex™ plasticizer series, sucrose based plasticizers, dibutyl sebacate, tributyrin, sucrose acetate isobutyrate, the Resolflex™ series of plasticizers, triphenyl phosphate (TPP), triethyl phosphate (TEP), glycolates(e.g. , ethyl phthalyl ethyl glycolate “EPEG” and methyl phthalyl ethyl glycolate “MPEG”), methoxy polyethylene glycol, 2,2,4-trimethylpentane-1 ,3-diyl bis(2- methylpropanoate), and polycaprolactones. In some embodiments, the plasticizer used herein may comprise a combination or mixture of two or more different types of plasticizers.

[0052] In one embodiment or in combination with any other embodiment, the plasticizer is a food-compliant plasticizer. By food-compliant is meant compliant with applicable food additive and / or food contact regulations where the plasticizer is cleared for use or recognized as safe by at least one (national or regional) food safety regulatory agency (or organization), for example listed in the 21 CFR Food Additive Regulations or otherwise Generally Recognized as Safe (GRAS) by the US FDA. In one embodiment or in combination with any other embodiment, the food-compliant plasticizer is triacetin or polyethylene glycol (PEG) having a molecular weight of about 200 to about 600. In one embodiment or in combination with any other embodiment, examples of food-compliant plasticizers that could be considered can include triacetin, triethyl citrate, polyethylene glycol, Benzoflex, propylene glycol, polysorbate, sucrose octaacetate, acetylated triethyl citrate, acetyl tributyl citrate, Admex, tripropionin, Scandiflex, poloxamer copolymers, polyethylene glycol succinate, diisobutyl adipate, polyvinyl pyrollidone, and glycol tribenzoate.

[0053] In one embodiment or in combination with any other embodiment, the plasticizer can be present in an amount sufficient to permit the cellulose ester composition to be melt processed (or thermally formed) into useful articles, e.g., single use plastic articles, in conventional melt processing equipment. In one embodiment or in combination with any other embodiment, the plasticizer is present in an amount from 1 to 40 wt% for most thermoplastics processing; or 5 to 25 wt%, or 10 to 25 wt%, or 12 to 20 wt% based on the weight of the cellulose ester composition. In one embodiment or in combination with any other embodiment, profile extrusion, sheet extrusion, thermoforming, and injection molding can be accomplished with plasticizerlevels in the 10-30, or 12-25, or 15-20, or 10-25 wt% range, based on the weight of the cellulose ester composition.

[0054] In one embodiment or in combination with any other embodiment, the plasticizer is a biodegradable plasticizer. Some examples of biodegradable plasticizers include triacetin, triethyl citrate, acetyl triethyl citrate, polyethylene glycol, the benzoate containing plasticizers such as the Benzoflex™ plasticizer series, poly (alkyl succinates) such as poly (butyl succinate), polyethersulfones, adipate based plasticizers, soybean oil epoxides such as the Paraplex™ plasticizer series, sucrose based plasticizers, dibutyl sebacate, tributyrin, the Resoflex™ series of plasticizers, triphenyl phosphate, glycolates, polyethylene glycol, 2,2,4-trimethylpentane- 1 ,3-diyl bis(2-methylpropanoate), and polycaprolactones.

[0055] In one embodiment or in combination with any other embodiment, the cellulose ester composition can contain a plasticizer selected from the group consisting of PEG and MPEG (methoxy PEG). The polyethylene glycol or a methoxy polyethylene glycol composition having an average molecular weight of from 200 Daltons to 600 Daltons, wherein the composition is melt processable, biodegradable, and disintegrable.

[0056] In one embodiment or in combination with any other embodiment, the composition comprises polyethylene glycol or methoxy PEG having an average molecular weight of from 300 to 550 Daltons.

[0057] In one embodiment or in combination with any other embodiment, the composition comprises polyethylene glycol having an average molecular weight of from 300 to 500 Daltons.

[0058] In one embodiment or in combination with any other embodiment, the cellulose ester composition comprises at least one plasticizer (as described herein) in an amount from 1 to 40 wt%, or 5 to 40 wt%, or 10 to 40 wt%, or 12 to 40 wt%, 13 to 40 wt%, or 15 to 40 wt%, or greater than 15 to 40 wt%, or 17 to 40 wt%, or 20 to 40 wt%, or 25 to 40 wt%, or 5 to 35 wt%, or 10 to 35 wt%, or 13 to 35 wt%, or 15 to 35 wt%, or greater than 15 to 35 wt%, or 17 to 35 wt%, or 20 to 35 wt%, or 5 to 30 wt%, or 10 to 30 wt%, or 13 to 30 wt%, or 15 to 30 wt%, or greater than 15 to 30 wt%, or 17 to 30 wt%, or 5 to25 wt%, or 10 to 25 wt%, or 13 to 25 wt%, or 15 to 25 wt%, or greater than 15 to 25 wt%, or 17 to 25 wt%, or 5 to 20 wt%, or 10 to 20 wt%, or 13 to 20 wt%, or 15 to 20 wt%, or greater than 15 to 20 wt%, or 17 to 20 wt%, or 5 to 17 wt%, or 10 to 17 wt%, or 13 to 17 wt%, or 15 to 17 wt%, or greater than 15 to 17 wt%, or 5 to less than 17 wt%, or 10 to less than 17 wt%, or 13 to less than 17 wt%, or 15 to less than 17 wt%, all based on the total weight of the cellulose ester composition.

[0059] In one embodiment or in combination with any other embodiment, the at least one plasticizer includes or is a food-compliant or FDA approved plasticizer. In one embodiment or in combination with any other embodiment, the food-compliant or FDA approved plasticizer includes or is triacetin or PEG MW 300 to 500.Biodegradable Polymers

[0060] In one embodiment or in combination with any other embodiment, the cellulose ester compositions described herein comprise a biodegradable cellulose ester (BCE) component that comprises at least one BCE, which may include one or more of the cellulose esters described herein, and a biodegradable polymer component that comprises at least one other biodegradable polymer (other than the BCE). In one embodiment or in combination with any other embodiment, the other biodegradable polymer can be chosen from polyhydroxyalkanoates (PHAs and PHBs), polylactic acid (PLA), polycaprolactone polymers (PCL), polybutylene adipate terephthalate (PBAT), polyethylene succinate (PES), polyvinyl acetates (PVAs), polybutylene succinate (PBS) and copolymers (such as polybutylene succinate-co-adipate (PBSA)), cellulose esters, cellulose ethers, starch, proteins, derivatives thereof, and combinations thereof. In one embodiment or in combination with any other embodiment, the cellulose ester composition comprises two or more biodegradable polymers. In one embodiment or in combination with any other embodiment, the cellulose ester composition contains a biodegradable polymer (other than the BCE) in an amount from 0.1 to less than 50 wt%, or 1 to 40 wt%, or 1 to 30 wt%, or 1 to 25 wt%, or 1 to 20wt%, based on the cellulose ester composition. In one embodiment or in combination with any other embodiment, the cellulose ester composition contains a biodegradable polymer (other than the BCE) in an amount from 0.1 to less than 50 wt%, or 1 to 40 wt%, or 1 to 30 wt%, or 1 to 25 wt%, or 1 to 20 wt%, based on the total amount of BCE and biodegradable polymer. In one embodiment or in combination with any other embodiment, the at least one biodegradable polymer comprises a PHA having a weight average molecular weight (Mw) in a range from 10,000 to 1 ,000,000, or 50,000 to 1 ,000,000, or 100,000 to 1 ,000,000, or 250,000 to 1 ,000,000, or 500,000 to 1 ,000,000, or 600,000 to 1 ,000,000, or 600,000 to 900,000, or 700,000 to 800,000, or 10,000 to 500,000, or 10,000 to 250,000, or 10,000 to 100,000, or 10,000 to 50,000, measured using gel permeation chromatography (GPC) with a refractive index detector and polystyrene standards employing a solvent of methylene chloride. In one embodiment or in combination with any other embodiment, the PHA can include a polyhydroxybutyrate-co- hydroxyhexanoate.Nucleating Agent

[0061] Nucleating agent means a chemical or physical material that provides sites for cells to form in a molten formulation mixture, such as within a CE melt resin. Such nucleating agents are generally added to aid in the formation of foams. As such, nucleating agents may be added to relevant processes when forming foam articles, but may not be added to relevant processes when forming rigid articles. As will be described in more detail below, nucleating agents may be added to compounded CE material during the compounding process. Alternatively, or in addition, nucleating agents may be added during the foam sheet production process. For example, the nucleating agents may be blended with the formulation that is introduced into the hopper of the extruder of the extruding section. Alternatively, the nucleating agents may be added to the CE melt resin in the extruder itself. Nucleating agents may include physical nucleating agents and chemical nucleating agents. Physical nucleating agents are materials that are immiscible with the polymer matrix of the CE melt resin at the extrusiontemperature of the extrusion section. Chemical nucleating agents are materials that react (e.g., decompose) during extrusion (e.g., at the extrusion temperature within the extruder) to form physical nucleating agents. Thus, chemical nucleating agents may be considered (and referred to herein as) precursors of in situ formed physical nucleating agents.

[0062] Suitable physical nucleating agents will comprise fine particles having desirable particle sizes and / or shapes to create cell nucleation sites within the CE melt resin. For example, in some embodiments, physical nucleating agents will have a mean particle size of less than 1000 microns, less than 500 microns, less than 100 microns, less than 50 microns, less than 25 microns, less than 20 microns, less than 10 microns, less than 5 microns, less than 2 microns, less than 1.5 microns, and / or less than 1.0 microns. However, in some other embodiments, it may be preferred to have nanoscalesized particles. Furthermore, it some embodiments, physical nucleating agents will preferably have a high aspect ratio (i.e., width:height). For example, in some embodiments, physical nucleating agents will have a mean aspect ratio of greater than 1 :1 , greater than 2: 1 , greater than 5:1 , greater than 10: 1 , greater than 20:1 , greater than 30:1 , greater than 40:1 , greater than 50: 1 , greater than 75:1 , and / or greater than 100:1. Furthermore still, as noted above, physical nucleating agents should be immiscible with the polymer matrix of the CE melt resin at the extrusion temperature of the extrusion section. As such, in some embodiments, the physical nucleating agents should have a melting temperature at least 220° C, at least 230° C of at least 240° C, at least 250° C, at least 275° C, at least 300° C, at least 325° C, or at least 350° C. Nevertheless, the physical nucleating agents may be selected such that they have the ability to, after melting, recrystallize upon cooling.

[0063] Examples of suitable inorganic physical nucleating agents include, but are not limited to, minerals such as talc, CaCOs, mica, and mixtures of at least two of the foregoing. One representative example is Heritage Plastics HT6000 Linear Low Density Polyethylene (LLDPE) Based Talc Concentrate. Other inorganic physical nucleating agents include wollastonite, silica, siliconoxide, titanium oxide, magnesium oxide, aluminum oxide and calcium silicate, barium sulfate, Kaolin, aluminum tryhydrateATH (AI(OH)s), MDH (Mg(OH)2), Diatomaceous earth, magnetite / hematite, halloysite, zinc oxide, and titanium dioxide. In some embodiments, the inorganic nucleating agents will comprise oxides, such as metal oxides or mixed metal oxides, such as those selected from one or more of the following: aluminum oxide, antimony oxide, arsenic oxide, bismuth oxide, boron oxide, calcium oxide, gallium oxide, iron oxide, lithium oxide, magnesium oxide, silicon oxide, and titanium oxide. In other embodiments, the inorganic nucleating agents will comprise silicates, such as silicates selected from one or of the following: magnesium silicate and calcium silicate.

[0064] It has been discovered that biodegradable natural, particulate materials derived from renewable organic sources (e.g., organic nucleating agents) can also serve as effective physical nucleating agents. Natural materials that can be physical nucleating agents include material comprised of cellulose fibers and / or cellulose starch. Examples include, but are not limited to almond shell flour, animal fiber, apricot shell flour, bamboo flour, tree bark flour, clam shell flour, coconut shell flour, coconut coir, corn flour, corn cob flour, corn cob grit, cottonseed hulls, flock & fiber, hazelnut shell flour, kenaf flour, natural fibers, nutshell hull & flour, oat fiber powder, olive stone flour, peanut hulls flour, pecan shell flour, pine-nut shell powder, pistachio-nut shell flour, plant fiber, rice hull flour, rice hull grit, rice husk, soy bean flour, starch flour (hydrophobic), walnut shell flour, wheat chaff, wheat husk, and wood flour. Other organic physical nucleating agents include cellulose powder, chitin, chitosan, stearic acid metal salts, carbon black, and dolomite.

[0065] As noted above, suitable chemical nucleating agents (or precursors of in situ formed physical nucleating agents) are configured to decompose to create cell nucleation sites in the CE melt resin when a threshold chemical reaction temperature is reached. These small cells act as nucleation sites for larger cell growth from a physical or other type of blowing agent. In some embodiments, the precursors are configured to form a gas during extrusion of the particulate material, such as CO2 or N2.

[0066] Examples of chemical nucleating agents include but are not limited to acids, such as citric acid or a citric acid-based material. Other acids may include lauric acid, stearic acid, tartaric acid, ascorbic acid, propionic acid, and hexanoic acid. One representative example is HYDROCEROL™ CF-40E (available from Clariant Corporation), which contains citric acid and a crystal nucleating agent. In some embodiments, the chemical nucleating agents will include a combination of an acid and a base, such as a carbonate, which may include sodium bicarbonate, zinc bicarbonate, potassium bicarbonate, sodium carbonate, potassium carbonate, etc. For instance, a representative example of a chemical nucleating agent is a combination of citric acid and sodium bicarbonate. In some embodiments, chemical nucleating agents may include a carrier within which the active components of the nucleating agents are dispersed. For example, yet another representative example of chemical nucleating agents is a combination of citric acid, sodium bicarbonate, and a carrier. In some embodiments, the carrier may comprise polystyrene.However, the carrier may comprise other compositions, such as various biopolymers (e.g., polybutylene succinate, Capa polyesters, etc.), polyolefins, acrylic copolymers (e.g., ethylene methyl acrylate), or the like. In some such embodiments, the citric acid and sodium bicarbonate may comprise about half (in wt%) of the chemical nucleating agents, while the carrier makes up the remaining half (in wt%). Furthermore, in some of such embodiments, there may be more sodium bicarbonate than citric acid in the chemical nucleating agent. For instance, there may be about three times as much (in wt%) sodium bicarbonate than citric acid in the chemical nucleating agent. It should also be understood that in some embodiments, no carrier may be required or used, such as the case with the nucleating agent being Hecofoam or Hydrocerol.

[0067] In one embodiment or in combination with any of the embodiments mentioned herein, the nucleating agents are present at from 0.1 to 10 wt%, from 0.1 to 5.0 wt%, at least 0.1 wt%, at least 0.25 wt%, at least 0.5 wt% at least 1 .0 wt%, at least 1 .25 wt%, at least 1 .5 wt%, at least 1.75 wt%, at least 2.0 wt%, at least 2.25 wt%, at least 2.5 wt%, at least 2.75 wt%, or at least 3.0 wt%, or at least 3.5 wt%, or at least 4.0 wt%, or at least 4.5 wt% and / or lessthan 7.5 wt%, less than 5 wt%, less than 4 wt%, less than 3 wt%, less than 2 wt%, or less than 1.0 wt%, all based on the total weight of the cellulose ester composition. In some embodiments, the nucleating agents used herein may comprise a combination or mixture of two or more different types of nucleating agents, including two or more chemical nucleating agents, two or more physical nucleating agents, and / or a combination of chemical and physical nucleating agents.

[0068] It is noted that the cellulose ester material, whether in the form of compounded CE material or CE melt resin, will generally be able to accept a maximum amount of nucleating agent that can function to form nucleation sites. Any remaining nucleating agent that is added to the cellulose ester material will remain as filler. Fillers can provide various properties to the resulting cellulose ester foams and / or articles based on the type of filler used. For example, some fillers can provide increased / decreased density, ductility, Young’s modulus, yield strength, heat deflection temperature, permeability, impact resistance, elongation to break, adhesion properties, biodegradation, etc. of the cellulose ester material. Fillers can also be used to alter the visual characteristics (e.g., color, opacity, etc.) and tactile characteristics (e.g., material continuous, surface roughness, etc.) of the cellulose ester material. In addition to other fillers described herein, exemplary illustrations of fillers include talc and CaCO3.

[0069] In any of the embodiments for the cellulose ester material or composition, the material or composition can comprise at least one filler. In embodiments, the filler is of a type and present in an amount to enhance biodegradability and / or compostability. In other embodiments, the filler is of a type and present in an amount to enhance processing or properties of a final product made from the CE material / composition. In embodiments, the cellulose ester, e.g., cellulose acetate, composition comprises at least one filler chosen from: carbohydrates (sugars and salts), cellulosic and organic fillers (wood flour, wood fibers, hemp, carbon, coal particles, graphite, and starches), mineral and inorganic fillers (calcium carbonate, talc, silica, titanium dioxide, glass fibers, glass spheres, boronitride, aluminum trihydrate,magnesium hydroxide, calcium hydroxide, alumina, and clays), food wastes or byproduct (eggshells, distillers grain, and coffee grounds), desiccants (e.g. calcium sulfate, magnesium sulfate, magnesium oxide, calcium oxide), alkaline fillers (e.g., Na2CO3, MgCO3), or combinations (e.g., mixtures) of these fillers. In embodiments, the cellulose acetate compositions can include at least one filler that also functions as a colorant additive. In embodiments, the colorant additive filler can be chosen from: carbon, graphite, titanium dioxide, opacifiers, dyes, pigments, toners and combinations thereof. In embodiments, the cellulose acetate compositions can include at least one filler that also functions as a stabilizer or flame retardant.Blowing Agents

[0070] A blowing agent refers to a physical or a chemical material (or combination of materials) that acts to expand nucleation sites. Such blowing agents are generally added to aid in the formation of foams. As such, blowing agents may be added to relevant processes when forming foam articles, but may not be added to relevant processes when forming rigid articles. Blowing agents may include chemical blowing agents, physical blowing agents, combinations thereof, or several types of chemical and physical blowing agents. The blowing agents function to reduce density of a material by expanding cells formed in the molten formulation at the nucleation sites. The blowing agent may be added to the CE melt resin in the extruder. It has been surprisingly discovered that the hygroscopic nature of biodegradable particulate natural fillers allows them to absorb moisture and carry the absorbed water into the molten resin mixture where the water can act as a physical blowing agent.

[0071] Examples of physical blowing agents include H2O, N2, CO2, alkanes, alkenes, ethers, ketones, argon, helium, air or mixtures. In addition, it has been surprisingly discovered that the hygroscopic nature of biodegradable particulate natural fillers allows them to absorb moisture and carry the absorbed water into the molten resin mixture where the water can act as a physical blowing agent. Hygroscopic biodegradable natural fillers canbe formulated into a composition and allowed to absorb moisture prior to the foaming process, where the water then is released to act as a physical blowing agent. Beneficially, the water may also be used as a plasticizer for the cellulose ester resin. Furthermore, in some embodiments, physical blowing agents may include hydrocarbons, such as pentane / isopentane or butane / isobutane. Other hydrocarbons may include propane, ethane, methane, hexane, cyclohexane, cyclopentane, cyclobutene, or the like.

[0072] Chemical blowing agents are materials that degrade or react to produce a gas (e.g., CO2 or N2). Such gasses expand the cells within the molten resin mixture and / or resulting foam mixture to produce a structural material with a plurality of gaseous voids dispersed throughout. Chemical blowing agents may be endothermic or exothermic. Chemical blowing agents typically degrade at a certain temperature to decompose and release gas. Examples of chemical blowing agents include azodicarbonamide, acids (e.g., citric acid), and carbonates, such as sodium bicarbonate, sodium carbonate, ammonium bicarbonate, ammonium carbonate, zinc carbonate, and the like and combinations thereof.

[0073] In one embodiment or in combination with any of the embodiments mentioned herein, the blowing agent is present at from 0.3 to 1 .5 wt%, or 0.3 to 2.0 wt%, or 0.3 to 2.5 wt%, or 0.3 to 3.0 wt%, or 0.3 to 3.5 wt%, or 0.3 to 4.0 wt%, or 0.3 to 8%, or 1 .3 to 1 .5 wt%, or 1 .3 to 2.0 wt%, or 1 .3 to 2.5 wt%, or 1 .3 to 3.0 wt%, or 1 .3 to 3.5 wt%, or 1 .3 to 4.0 wt%, or 1 .3 to 4.5 wt%, or 1 .3 to 5.0 wt%, or 1 .3 to 5.5 wt%, or 1 .5 to 3.0 wt%, or 1 .5 to 4.0 wt%, or 1 .5 to 5.0 wt%, or 1 .5 to 6.0 wt%, or 2.0 to 3.0 wt%, or 2.0 to 4.0 wt%, or 2.0 to 5.0 wt%, or 2.0 to 6.0 wt%, or 2.5 to 3.0 wt%, or 2.5 to 4.0 wt%, or 2.5 to 5.0 wt%, or 2.5 to 6.0 wt%, or 3.0 to 4.0 wt%, or 3.0 to 5.0 wt%, or 3.0 to 6.0 wt%, or 0.0 to 9.0 wt%, or 0.5 to 9.0 wt%, or 1 .0 to 9.0 wt%, or 1 .5 to 9.0 wt%, or 2.0 to 9.0 wt%, or 2.5 to 9.0 wt%, or 3.0 to 9.0 wt%, or 3.5 to 9.0 wt%, or 4.0 to 9.0 wt%, or 4.5 to 9.0 wt%, or 5.0 to 9.0 wt%, or 5.5 to 9.0 wt%, or 6.0 to 9.0 wt%, or 6.5 to 9.0 wt%, or 7.0 to 9.0 wt%, or 7.5 to 9.0 wt%, or 8.0 to 9.0 wt%, or 8.5 to 9.0 wt%, all based on the total weight of the cellulose ester composition. In some embodiments, the blowing agents used herein maycomprise a combination or mixture of two or more different types of blowing agents, such as two or more chemical blowing agents, two or more physical blowing agents, and / or a combination of chemical and physical blowing agents.Surface Modifying Additives

[0074] Surface modifying additives refer to materials that can be added to cellulose ester compositions to modify the structure of the compositions (or the resulting foam articles) to improve processing of the cellulose ester compositions. For example, the inventors of the present application have found that adding surface modifying additives to the compounded CE material (e.g., to the pellets during the compounding process) or to the CE melt resin (e.g., during the extrusion process) can improve processing by reducing unwanted sticking of the CE melt resin to the die or mandrel (or to other components of the foam sheet or rigid article production process). Such reduction in sticking may be achieved by the surface modifying additives inhibiting the fusing of cellulose esters caused by plasticizers. The addition of surface modifying additives may also reduce blocking of the cellulose ester foam sheets produced at the sheet forming section or the injection molding section. Furthermore, surface modifying additives may also improve the foam sheet production process or the rigid article production process by allowing the process to be performed at lower temperatures.

[0075] Furthermore still, in some embodiments, the surface modifying additives may function as anti-static additives, which inhibit electrical sparks or arcing in the CE melt resin. The inhibition of electrical sparks or arcing can be particularly important when hydrocarbons are used as blowing agents, so as to reduce the chance of igniting the hydrocarbons and causing fires. Beneficially, surface modifying additives may also reduce the diffusion of blowing agents, such as hydrocarbons, out of the foam sheets or resulting articles. In some embodiments, hydrocarbons themselves may be used as surface modifying additives.

[0076] Nevertheless, more general examples of surface modifying additives that may be used with compounded CE material (e.g., during the compounding process) or to the CE melt resin (e.g., during the foam sheet production process) according to embodiments of the present invention include fatty acids, such as palmitic acid, tallow acid, stearic acid, oleic acid, linoleic and linolenic acids, arachidic / behenic acids, behenic acid, and erucic acid. Surface modifying additives may also include fatty acid amides, such as erucamides, oleoamides, stearmides, bhenamides, secondary amides, and bisamides.

[0077] Additional examples of surface modifying additives may include glycerol esters and / or stearate esters, such as monoglycerides, diglycerides, and triglycerides. The monoglycerides may include glycerol monostearate or monoglyceride derivatives, such as diacetyl tartaric acid esters of mono- and diglycerides (DATEM), ethoxylated monoglyceride, succinyl monoglyceride, and propylene glycol monoesters (PGME). Examples of surface modifying additives may also include metallic stearates such as aluminum stearate, calcium stearate, lithium stearate, magnesium stearate, sodium stearate, zinc stearate, and / or combinations thereof (e.g., Calcium / Zinc stearates) . Examples of surface modifying additives may also include waxes, such as polyolefin waxes (polypropylene wax and polyethylene wax), oxidized olefin waxes, ethylene acrylic acid (EAA) copolymer waxes, ethylene methyl acrylate (EMA) copolymer waxes, EAA ionomer axes, acrylic waxes, and / or natural waxes, such as rice bran wax, sunflower wax, sugar cane wax, candelilla wax, soy wax, bees wax, candelilla wax, and carnauba waxes.

[0078] Other, non-exclusive examples of surface modifying additives include aliphatic diesters (e.g., dioctyl adipate), polyglycol diesters, alkyl alkyether diesters, aromatic triesters, polyester resins, chlorinated hydrocarbons, halogenated hydrocarbons, alkylether monoesters, and alkyl monoesters. In addition, various oils may be used as surface modifying additives, such as aromatic oils, napthenic oils, glyceride oils, silicon oils, and epoxidized oils (e.g., soybean oil and linseed oil). Thus, in some embodiments, the surface modifying additives comprise plasticizers, such asaliphatic diester plasticizers, polyester plasticizers, and the like. Furthermore, in some embodiments, surface modifying additives may comprise a polyhedral oligomeric silsesquioxane (POSS).

[0079] More generally, surface modifying additives used in embodiments of the present invention may have a lower polarity than the cellulose ester in compounded CE material (e.g., during the compounding process) or to the CE melt resin (e.g., during the foam sheet production process). For example, the surface modifying additives may have (based on Hansen solubility parameters): a total solubility parameter 6 of less than 25 MPa1 / 2, less than 20 MPa1 / 2, or less than 19.5 MPa1 / 2; a dispersion force solubility parameter 3d of less than 18 MPa1 / 2, less than 16 MPa1 / 2, or less than 14 MPa1 / 2; a dipolar intermolecular force solubility parameter 3d of less than 12 MPa1 / 2, less than 8 MPa1 / 2, or less than 4 MPa1 / 2; and / or a hydrogen bond solubility parameter 3h of less than 11 MPa1 / 2, less than 10 MPa1 / 2, or less than 9 MPa1 / 2. However, in some other embodiments, the surface modifying additives used in embodiments of the present invention may have a higher polarity than the cellulose ester in compounded CE material (e.g., during the compounding process) or to the CE melt resin (e.g., during the foam sheet production process). For example, the surface modifying additives may have (based on Hansen solubility parameters): a total solubility parameter 0 of more than 21 .5 MPa1 / 2, more than 23 MPa1 / 2, or more than 25 MPa1 / 2. In addition, in some embodiments, surface modifying additives may have a boiling point greater than 200° C, greater than 220° C, greater than 240° C, greater than 260° C, greater than 280° C, or greater than 300° C.Furthermore, the surface modifying additives may have a molecular weight greater than 100 g / mol, greater than 150 g / mol, greater than 220 g / mol, greater than 260 g / mol, greater than 300 g / mol, or greater than 340 g / mol and / or no more than 1000 g / mol, no more than 2500 g / mol, or no more than 5000 g / mol. Furthermore still, it may be preferable for the surface modifying additives to not be soluble in the plasticizer(s) used in the cellulose ester compositions. For instance, it may be preferable for the surface modifying additives to not be soluble in triacetin. Finally, in some embodiments, thesurface modifying additives may be biodegradable and / or food-compliant or FDA approved.

[0080] In one embodiment or in combination with any of the embodiments mentioned herein, the surface modifying additives are present at from 0.05 to 0.75 wt%, or 0.05 to 1 .0 wt%, or 0.05 to 2.5 wt%, or 0.05 to 5.0 wt%, or 0.75 to 1.0 wt%, or 0.75 to 2.5 wt%, or 0.75 to 5.0 wt%, or 0.1 to 1.0 wt%, or 0.1 to 2.5 wt%, 0.1 to 5.0 wt%, or 1 .0 to 2.5 wt%, or 1.0 to 5.0 wt%, or 2.5 to 5.0 wt%, all based on the total weight of the cellulose ester composition. In some embodiments, the surface modifying additives used herein may comprise a combination or mixture of two or more different types of surface modifying additives.Articles

[0081] Extruded sheets of cellulose ester foam may be formed using the extrusion section and / or the sheet forming section described above. Such extruded sheets comprise a structural material with a plurality of gaseous voids disposed throughout. Such gaseous voids are formed by expansion of the blowing agent in the form of a gas within the cellulose polymer melt. The structural material is cellulose ester based, and in some embodiments with specific amounts of the compositional components of the structural material (e.g., cellulose ester, plasticizer, nucleating agents, surface modifying additives, etc.) having been described above in more detail. Foam articles may be formed from the extruded sheets of foam in accordance with embodiments, e.g., via thermoforming, and may be particularly useful in the food service industry. Exemplary articles include food trays, clam shells, egg cartons, etc. The articles may have one or more particularly advantageous properties. For example, the articles may be biodegradable, compostable, recyclable and / or the articles may have superior mechanical properties (e.g., strength, density, cell size, absorption, etc.).

[0082] In one embodiment or in combination with any of the embodiments mentioned herein, the foam has a density less than .20 g / cm3, less than 0.18 g / cm3, less than 0.15 g / cm3, less than 0.12 g / cm3, less than less than 0.10g / cm3, less than 0.08 g / cm3, less than less than 0.06 g / cm3, or less than less than 0.04 g / cm3, or from 0.04 to 0.8 g / cm3, 0.04 to 0.6 g / cm3, 0.04 to 0.5 g / cm3, 0.04 to 0.4 g / cm3, 0.04 to 0.3 g / cm3, 0.04 to 0.2 g / cm3, 0.04 to 0.15 g / cm3, 0.04 to 0.12 g / cm3, 0.04 to 0.10 g / cm3, 0.04 to 0.08 g / cm3, 0.04 to 0.06 g / cm3, 0.06 to 0.8 g / cm3, 0.06 to 0.6 g / cm3, 0.06 to 0.5 g / cm3, 0.06 to 0.4 g / cm3, 0.06 to 0.3 g / cm3, 0.06 to 0.2 g / cm3, 0.06 to 0.15 g / cm3, 0.06 to 0.12 g / cm3, 0.06 to 0.10 g / cm3, 0.06 to 0.08 g / cm3, 0.08 to 0.8 g / cm3, 0.08 to 0.6 g / cm3, 0.08 to 0.5 g / cm3, 0.08 to 0.4 g / cm3, 0.08 to 0.3 g / cm3, 0.08 to 0.2 g / cm3, 0.08 to 0.15 g / cm3, 0.08 to 0.12 g / cm3, 0.08 to 0.10 g / cm3, 0.1 to 0.8 g / cm3, 0.1 to 0.6 g / cm3, 0.1 to 0.5 g / cm3, 0.1 to 0.4 g / cm3, 0.1 to 0.3 g / cm3, 0.1 to 0.2 g / cm3, 0.1 to 0.15 g / cm3, 0.1 to 0.12 g / cm3, 0.2 to 0.8 g / cm3, 0.2 to 0.6 g / cm3, 0.2 to 0.5 g / cm3, 0.2 to 0.4 g / cm3, 0.2 to 0.3 g / cm3, 0.3 to 0.6 g / cm3, 0.3 to 0.5 g / cm3, 0.3 to 0.4 g / cm3, 0.4 to 0.6 g / cm3, 0.4 to 0.5 g / cm3, or 0.5 to 0.6 g / cm3.

[0083] In one embodiment or in combination with any of the embodiments mentioned herein, the average foam cell size is from 40 pm to 600 pm, or 50 pm to 600 pm, or 60 pm to 600 pm, or 70 pm to 600 pm, or 80 pm to 600 pm, or 90 pm to 600 pm, or 100 pm to 600 pm, or 150 pm to 600 pm, or 200 pm to 600 pm, or 250 pm to 600 pm, or 300 pm to 600 pm, or 400 pm to 600 pm, or 500 pm to 600 pm, or 40 pm to 550 pm, or 40 pm to 500 pm, or 40 pm to 450 pm, or 40 pm to 400 pm, or 40 pm to 350 pm, or 40 pm to 300 pm, or 40 pm to 250 pm, or 40 pm to 200 pm, or 40 pm to 150 pm, or 40 pm to 100 pm.

[0084] Alternatively, or in addition, rigid articles may be formed from CE melt resin via injection molding, exemplary articles include straws, cups, lids, trays, bowls, cutlery, and the like. The articles may have one or more particularly advantageous properties. For example, the articles may be biodegradable, compostable, recyclable and / or the articles may have superior mechanical properties (e.g., strength, density, cell size, absorption, etc.).Further Inventive Concepts Related to Recycling Cellulose Ester Materials

[0085] Beneficially, the cellulose ester used and described herein may be used to form compounded CE material, CE melt resin, and / or resulting articles(e.g. , foam articles or rigid articles) that are recyclable. For example, when forming cellulose ester-based articles, scrap material (e.g., cellulose ester- based material in foam or rigid form) is generally created during thermoforming and / or injection molding, such as in the form of trim scrap. Instead of sending such scrap to waste, embodiments of the present invention provide for such cellulose ester-based scrap (i.e. , industrial scrap) to be recycled back into the foam article production process and / or the rigid article production process. In still other embodiments, it is contemplated that the entirety of the cellulose ester-based articles (or portions thereof) may be recycled after manufacture or after sale to and / or use by consumers (i.e., post-consumer scrap).

[0086] In more detail, as illustrated in FIG. 8, during the foam article forming process, which forms cellulose ester-based foam articles from cellulose ester-based foam sheets, scrap material can be collected. Such scrap material is often generated during the thermoforming process. The scrap material can then be processed through a regrinding process that grinds the scrap down into small particulates that can be added back into the foam sheet production process. The regrinding process may be performed by any machine or process that is capable of shredding or grinding the scrap material into small enough particulates (e.g., flakes or pellets) to be added back into the extruder of the foam sheet production process. In some embodiments, particularly when the scrap material is a foam material, the scrap material will need to undergo a densification process, such that the density of the foam scrap material is increased to a level that is more closely aligned with the virgin feedstock (i.e., the compounded CE material) that is provided to the extruder of the foam sheet production process. The regrinding and / or densification process may be performed by a shredder, a grinder, a roll mill, a pellet mill, an extruder (e.g., single-screw or twin-screw). In certain embodiments, additional plasticizer can be added to the reground CE before or during the regrinding and / or densification process. In embodiments, the additional plasticizer can comprise one or more plasticizers as described herein. In one embodiment, the additional plasticizer is the same plasticizerthat is already contained in the regrind CE source material, e.g., the CE scrap that is being reground. In embodiments, the additional plasticizer is added in an amount sufficient to change the Tg of the reground CE and make it closer to the Tg of the virgin CE material. In embodiments, the Tg of the reground CE is within 10%, or 5%, or 2% of; or less than 10°C higher than, or less than 5°C higher than, or less than 2°C higher than; the Tg of the virgin CE material.

[0087] Remaining with FIG. 8, once the scrap material is sufficiently reground, the scrap material may need to undergo a drying process to remove any excess moisture associated with the reground scrap material. For instance, the scrap material may need to be dried such that it includes a moisture content of less than 3000 ppm, less than 2000 ppm, or less than 1000 ppm. In some embodiments, the drying process may be separate from the regrinding process. For example, the drying process may be performed by an air dryer (e.g., a hot-air desiccant drying system), with the reground scrap material transferred to the air dryer after regrinding. In other embodiments, the drying process may be integrated with the regrinding process. For example, in some embodiments, the machine used to regrind the scrap material (e.g., pellet mill or extruder) may include one or more vents, such that moisture can be collected and drawn away from the scrap material during the regrinding and / or densification process. In still other embodiments, the collection, regrinding, and feeding of scrap material back into the foam sheet production process may be performed under an inert gas atmosphere, such that the scrap material remains relatively dry and free from moisture.

[0088] Regardless, once the scrap material has been reground (and perhaps densified and dried), the reground scrap material may be added back into the foam sheet production process, along with virgin feedstock (e.g., compounded CE material) and any other necessary additives (e.g., colors and fillers) to form cellulose ester-based foam sheets and / or foam articles that are comprised of a mixture of virgin and recycled cellulose ester materials. As used herein “virgin” material or feedstock means a formulated material comprising cellulose ester and plasticizer that has not yet been processed intomelt resin or article. As such, the virgin cellulose ester material or feedstock may be in the form of the compounded CE material previously described.

[0089] The above description illustrates how scrap material from foam articles may be recycled. However, embodiments of the present invention further contemplate that scrap material from cellulose ester-based rigid articles similarly be recycled. In more detail, as illustrated in FIG. 9, during the rigid article forming process, which may use injection molding of cellulose ester melt resin to form cellulose ester-based rigid articles, scrap material can be collected. The scrap material can then be processed through a regrinding process that grinds the scrap down into small particulates (e.g., flakes or pellets) that can be added back into the rigid article production process. Unlike foam scrap, however, the rigid scrap will generally not require densification, as the density of the scrap is generally consistent with the density of the virgin feedstock. The reground scrap material may then be dried, such as in any of the same processes described above for foam scrap, and reintroduced into the rigid article production process. Specifically, once the scrap material has been reground (and perhaps dried), the reground scrap material may be added back into the rigid article production process, along with virgin feedstock (e.g., compounded CE material) and any other necessary additives (e.g., colors and fillers) to form cellulose ester-based rigid articles that are comprised of a mixture of virgin and recycled cellulose ester. In certain embodiments, scrap material from cellulose ester-based rigid articles can be reground and recycled into a cellulose ester-based foam processes, applications or articles.

[0090] To permit the use of recycled cellulose ester in the manufacture of articles (e.g., foam or rigid articles), the cellulose ester that is used according to embodiments of the present invention is particularly configured to provide beneficial polymer degradation and / or color stability properties when the recycled and virgin polymers are combined together. In some embodiments, such beneficial properties are facilitated by the cellulose ester having a preferential metals-to-sulfur molar ratio (M / S). For example, the cellulose ester (forming the virgin or recycled cellulose ester polymers) may have ametals-to-sulfur molar ratio (M / S) of at least 1.35, or 1 .35 to 10.0, or 1 .35 to 8.0, or 1.35 to 6.0, or 1.35 to 5.0, or 1.4 to 10.0, or 1.4 to 8.0, or 1.4 to 6.0, or 1 .4 to 5.0, or 1 .45 to 10.0, or 1 .45 to 8.0, or 1 .45 to 6.0, or 1 .45 to 5.0, or 1 .5 to 10.0, or 1.5 to 8.0, or 1 .5 to 6.0, or 1.5 to 5.0. It has been found that materials formed from such cellulose esters can be recycled at higher rates or percentages than previously-used cellulose ester polymers.

[0091] For example, as was described above with respect to FIGS. 8 and 9, cellulose ester scrap material may be obtained from article manufacturing processes, such as during or after the thermoforming and / or injection molding processes. Such scrap material may then be reground to form a reground scrap material. Generally, the reground scrap material will have a smaller size that the original scrap material. For instance, the reground scrap material may be particulated, such that the reground scrap material has a reduced size from the original scrap material. In some embodiments, the reground scrap material will have a size that is more similar to that of the virgin compounded CE material, which is generally pelletized (i.e., having generally regular / consistent shapes). In some embodiments, the reground scrap material may be pelletized into regular shapes (e.g., having round, oval, or pellet shapes). In other embodiments, the reground scrap material may be formed into irregular shapes, such as flake-like shapes. Such flakes may be formed with (i) a thicknesses up to 100 mils, having a density of 0.3 - 0.7 g / cm3, (ii) a thicknesses up to 40 mils, having a density of 0.7-1 .0 g / cm3, or (iii) a thicknesses up to 20 mils, having a density of 1.0 - 1 .3 g / cm3. Such flakes may be formed from foamed scrap and achieve such density through densification, such as during the regrinding process. Alternatively, such flakes may be formed from rigid material, such that no further densification is required during the regrinding process.

[0092] In other embodiments, such as when the reground scrap material is formed from foam scrap material, the reground scrap material may be densified such that the reground scrap material has a density of more than 0.3 g / cm3. For example, the original foam scrap material may have a density of less than 0.5 g / cm3, less than 0.3 g / cm3, 0.2 g / cm3, and / or less than 0.1g / cm3. As such, the scrap material may, in some embodiments, require densification to have a density that is closer to that of the virgin feedstock (e.g., the pelletized, compounded CE material), which is around 1.3 g / cm3. Specifically, the reground scrap material may be densified to have a density of more than 0.3 g / cm3, more than 0.5 g / cm3, from 0.3 g / cm3 to 1 .3 g / cm3, from 0.3 g / cm3 to 0.7 g / cm3, from 0.5 to 1.3 g / cm3, from 0.5 to 1.0 g / cm3, from 0.5 to 0.9 g / cm3, from 0.5 to 0.8 g / cm3, and / or from 0.5 g / cm3 to 0.7 g / cm3.

[0093] After regrinding and / or densification, the reground scrap material may, in some embodiments, be dried. The reground scrap material may be dried such that it has a moisture content of less than 3000 ppm, less than 2000 ppm, or less than 1000 ppm. In addition, virgin cellulose ester material / feedstock, such as virgin compounded CE material, may be obtained and dried. The virgin cellulose ester material / feedstock may be dried such that it has a moisture content of less than 1000 ppm. As such, the reground scrap material and the virgin feedstock may be combined in the extruder (perhaps initially via the feed hopper) to form the melt resin can be extruded to form foam sheets / articles and / or injection molded to form rigid articles. In certain embodiments, as discussed above, additional plasticizer can be added before or during the regrinding and / or densification process, or during the extrusion process or formation of the melt resin. Exemplary articles include extruded foamed sheets, extruded foamed films, extruded and thermoformed foamed articles, extruded non-foamed films, extruded fibers, extruded molded articles, such as extruded articles having extrusion profiles, as well as injection molded articles. Regardless, such foam sheets / articles and / or rigid articles will, thus, be formed from a mixture of virgin and recycled cellulose ester material.

[0094] In some embodiments, the melt resin or resulting articles (formed from a combination of virgin and recycled cellulose ester material) may comprise at least 10%, at least 15%, at least 20%, at least 25%, at least 30%, at least 35%, at least 40%, at least 50%, at least 60%, at least 65%, at least 70%, and / or at least 75% recycled cellulose ester material. Nevertheless, the melt resin and / or the resulting articles are formed with improved polymer degradation properties. For example, the melt resin (and / or resulting articles)formed according to the present invention may comprise a virgin cellulose ester feedstock, with the virgin cellulose ester feedstock being a formulated feedstock comprising a cellulose ester and a plasticizer. In addition, the melt resin (and / or resulting articles) may comprise at least ten percent (10%) recycled cellulose ester material, as measured based on the total weight of the melt resin (and / or resulting articles). Given such a composition of the melt resin, the resin (and / or resulting articles) nevertheless maintains a molecular weight (Mw) within seventy-five percent (75%) of a molecular weight (Mw) of the virgin cellulose ester feedstock. In some particular embodiment, the melt resin may have a molecular weight (Mw) that is within 80%, 85%, 90%, and / or 95% of the molecular weight (Mw) of the virgin cellulose ester feedstock. It is understood that, in some embodiments, the virgin cellulose ester feedstock has a molecular weight in a range from 50,000 to 250,000, from 60,000 to 200,000, from 70,000 to 160,000, from 80,000 to 150,000, from 90,000 to 100,000, or from 90,000 to 95,000 Daltons.

[0095] Furthermore, the improved polymer degradation properties of the melt resin and / or the resulting articles (formed from a combination of virgin and recycled cellulose ester material) may be defined by the ability of the melt resin and / or the resulting articles to maintain requisite T(g) and / or plasticizer levels. For example, given the above-described melt resin (and / or resulting articles) formed from a combination of recycled and virgin cellulose ester material, the melt resin (and / or resulting articles) maintains a glass transition temperature (Tg) that is equal to or higher than a glass transition temperature (Tg) of the virgin cellulose ester material. In some embodiments, the glass transition temperature (Tg) of the virgin cellulose ester feedstock is from 100 to 140C. In addition, the melt resin (and / or resulting articles) maintains a plasticizer content within eighty-five percent (85%) of a plasticizer content of the virgin cellulose ester feedstock. In some embodiments, the plasticizer content of the melt composition (and / or resulting articles) is within 87%, within 90%, within 92%, within 94%, within 95%, within 96%, within 98% and / or within 99% of the plasticizer content of the virgin cellulose ester material. Forexample, in some embodiments, the plasticizer content in the virgin cellulose ester feedstock is from 10 to 30 wt. %.

[0096] It should be understood that, in some embodiments, the T(g) and / or the plasticizer content of the melt resin (and / or resulting articles) formed from a combination of virgin and recycled cellulose ester material may be maintained at such above-described levels without the introduction of any additional plasticizer (other than what is integrally part of the virgin and / or recycled cellulose ester material). For example, the recycled cellulose ester material (e.g., the scrap material) will maintain various additives that may have been incorporated during its original processing, such as plasticizer, nucleating agents, blowing agents, nucleating agents, surface modifying additives, or any of the other additives discussed herein. Nevertheless, it should be understood that in some embodiments, certain additives may be independently added to the virgin and recycled cellulose ester materials so as to provide the melt resin (and / or resulting articles) with requisite properties.

[0097] For example, in some embodiments, various molecular weight enhancers may be added to the combination of the virgin and recycled cellulose ester materials so as to increase the molecular weight of the resulting melt resin (and / or resulting articles), thereby reducing polymer degradation. Such molecular weight enhancers may comprise passive enhancers, such as ultra-high molecular weight cellulose acetates.Alternatively, or in addition, such molecular weight enhancers may comprise active enhancers, such as chain extenders. Exemplary chain extenders may include multifunctional epoxides, multifunctional isocyanates, and / or acrylates. Some particularly exemplary chain extenders include those sold under the tradename JONCRYL.

[0098] Other potential additives that may be independently added to the virgin and recycled cellulose ester materials, include color stabilizers that provide the resulting melt resin (and / or resulting articles) with enhanced color stability. Such color stabilizers may include: citric acid, acetic acid, propionic acid, butyric acid, valeric acid, tartaric acid, oxalic acid, malic acid, benzoic acid, formate, acetate, propionate, butyrate, valerate citrate, tartarate, oxalate,malate, maleic acid, maleate, phthalic acid, phosphite, phthalate, benzoate, and combinations thereof.

[0099] Regardless, the melt resin and / or resulting articles, which may be formed from a combination of virgin and recycled cellulose ester materials, may have beneficial color stability properties. For example, in some embodiments, the melt resin formed according to the present invention, may be configured such that when the melt resin is extruded into a 10 mil thick cellulose ester film, the cellulose ester film will exhibit a AE color difference (as described in more detail in the below example) of less than 3.0 units when compared with a 10 mil thick control film formed from virgin cellulose ester feedstock and no recycled cellulose ester material. In some additional embodiments, when the melt resin is extruded into a 10 mil thick cellulose ester film, the cellulose ester film will exhibit a AE color difference of less than 2.5, less than 2.0, less than 1 .5, less than 1 .0, less than 0.75, or less than 0.5 units and / or from 0.5 to 3.0, from 0.75 to 3.0, from 0.5 to 2.0, from 0.75 to 2.0, or from 0.5 to 1 .0, from 0.75 to 1 .0 units when compared with a 10 mil thick control film formed from virgin cellulose ester feedstock and no recycled cellulose ester material.

[0100] In additional embodiments, the melt resin formed according to the present invention, may be configured such that when the melt resin is extruded into a 10 mil thick cellulose ester film, the cellulose ester film will exhibit a Ab* color difference (as described in more detail in the below example) of less than 3.0 units when compared with a 10 mil thick control film formed from virgin cellulose ester feedstock and no recycled cellulose ester material. In some additional embodiments, when the melt resin is extruded into a 10 mil thick cellulose ester film, the cellulose ester film will exhibit a Ab* color difference of less than 2.5, less than 2.0, less than 1.5, less than 1.0, or less than 0.75 units and / or from 0.75 to 3.0, from 0.75 to 2.0, or from 0.75 to 1 .0 units when compared with a 10 mil thick control film formed from virgin cellulose ester feedstock and no recycled cellulose ester material.Example

[0101] The following example illustrates how cellulose ester based materials can be formed from a combination of virgin and recycled cellulose ester material, and yet retain beneficial color stability characteristics and molecular weights. In more detail, cellulose ester pellets were formed using a Sterling extruder configured with a 30:1 length to diameter design and fitted with a 1.25 inch diameter screw. To form the pellets, AVENTATM FT1150 virgin cellulose ester material (from Eastman Chemical Company) was fed into the extruder and melt processed at a temperature of 220° C and a screw speed of 90 rotations per minute. The resulting resin was extruded through a 2-hole strand die and cut into pellets by a pelletizer. The first pass of cellulose ester based material through the extruder, represented as a “control pass,” comprising one-hundred percent (100%) virgin cellulose ester and no (0%) recycled cellulose ester material. For each subsequent pass, seventy percent (70%) of the resin from the previous pass was re-fed into the extruder and blended with thirty percent (30%) virgin resin to simulate a seventy percent (70%) regrind operation. This process was replicated for ten additional passes, which are referred to herein as “pass 1” through “pass 10.” Pellets were made from the resins from each of the control pass and from passes 1 through 10.

[0102] From such pellets, eleven sample cellulose ester films were formed, one control film from the cellulose ester pellets from the control pass and one sample film from pellets obtained from each of the passes 1 through 10. The below description defines the Film Forming Procedure used herein, including as used within one or more of the claims of the present application. Each sample film was extruded using a 1 .5 inch Killion Lab extruder having a 24:1 length to diameter design. The films were extruded at a temperature of 248° C via casting onto a three roll stack having roll temperatures of 100° C. The speed of the roll stack was set at a rate to produce a film having a thickness of 10 mils. Sample films formed from cellulose ester from the control pass (i.e., the “Control Sample”) and from each of passes 1 through 10 (i.e., “Sample 1” through “Sample 10”) were then tested for various properties, including molecular weight and color stability, as provided in Table 1 below. Itshould be understood that the Control Sample (or “Control Film) is formed from virgin cellulose ester feedstock and no recycled cellulose ester material, whereas Sample 1 through Sample 10 (i.e., “Sample Films or “Test Films”) are formed with increasing amounts of recycled cellulose ester material.

[0103] In particular, each of the samples was tested using a Hunter Lab UltraScan Spectrophotometer (Model 8000) in reflectance mode and with a D65 llluminant* (Daylight, Noon World Average, -6500 °K correlated color temp). Color was measured directly to obtain L*, a*, and b* values according to ASTM D2244. As used herein, the terms L*, a*, and b* respectively denote color values from black to white, red to green, and yellow to blue, and are determined according to the CIE 1976 color space as specified by the International Commission on Illumination. From the measured L*, a*, and b* values, Aa*, Ab*, and AL* were calculated as the respective differences in a*, b* and L* values between the Control Sample and each of Sample 1 through Sample 10. For each sample, a AE value of the respective sample was determined according to the following equation: AE=[(Aa*)2+(Ab*):2+(AL*):2r / :2.Table 1

[0104] As shown in Table 1 , each of the Samples 1 through 10 included a AE color difference of less than 0.75 units with respect to the Control Sample. In addition, each of the Samples 1 through 10 included a Ab* color difference of less than 1 .0 units with respect to the Control Sample. Such a minimal colordifference between the Control Sample and the Samples 1 through 10 illustrate how the cellulose ester used in embodiments of the present invention allow for the elevated use of recycled cellulose ester material in melt resins and / or resulting articles, even with as much as 70% recycled cellulose ester material, with such melt resins and / or resulting articles having enhanced color stability. It is also noted from Table 1 that each of the Samples 1 through 10 had a molecular weight within 90% of the molecular weight of the Control Sample, even with as much as 70% recycled cellulose ester material, which indicates superior reduction in unwanted polymer degradation when incorporating recycled cellulose ester material within the melt resin and / or resulting articles.Examples - Molecular Weight Retention

[0105] The following examples illustrate how cellulose ester-based materials can be melt processed with the inclusion of varying amounts reground material that was already melt processed, while retaining acceptable properties for the final melt processed material.

[0106] The material used in the examples was Eastman Aventa FT1200, which is a formulated cellulose diacetate (CDA) that is plasticized with a 20 wt% target amount of triacetin plasticizer. The CDA had a target acetyl degree of substitution of 2.45, stabilized with metals M in an amount greater than 120 ppm M, and had a heated IV of 1 .107 dL / g.

[0107] Test samples were made to study the effect of various amounts of regrind on molecular weight when melt processing in a single screw extruder.Examples 11-20 (Multiple Pass 100% Regrind)

[0108] Samples were dried in a desiccant drying system prior to extruding. Dried samples were extruded using a 30 mm Sterling single screw extruder to make regrind pellets. The material received multiple passes through the extruder to represent a regrind process for thermoformed articles where trim scrap can be chopped up, re-pelletized and blended back with virgin feed pellets. Materials were melt compounded at temps of 210 to 240C and pelletized. The molecular weight was measured for the control (C-1 ) with no regrind and after each pass of regrind material. The results for 10 passes of regrind pellets are listed in Table 2 below.Table 2 - Multiple Pass for Single Screw Extruder

[0109] A review of table 2 reveals that the molecular weight retention was over 80% after 10 passes through the extruder.Examples 21-30 (Multiple Pass Blends with 50% Virgin)

[0110] Samples from examples 11-20 were then blended 50 wt% with virgin resin at 50wt% and 0.5 mm films were extruded on a 38 mm single screw Killion extruder. The films were extruded at zone temps from 210- 230°C, 56 rpm, and the films were cast onto an S-roll roll configuration having a roll temperature of 93°C. The molecular weight was measured for the control (C-1) with no regrind and after each pass with 50 wt% regrind material. The results for 10 blends of regrind films are listed in Table 3 below.Table 3 - 50 wt% Regrind Blends

[0111] A review of table 3 reveals that the molecular weight retention was over 86% for a blend with 50 wt% of Ex. 20 (that was subjected to 10 regrinding passes through an extruder).Examples 31-40 (Multiple Pass Blends with 75% Virgin)

[0112] Samples from examples 11 -20 were then blended 25 wt% with virgin resin at 75 wt% and 0.5 mm films were extruded on a 38 mm single screw Killion extruder. The films were extruded at zone temps from 210-230°C, 56 rpm, and the films were cast onto an S-roll roll configuration having a roll temperature of 93°C. The molecular weight was measured for the control (C-1 ) with no regrind and after each pass with 25 wt% regrind material. The results for 10 blends of regrind films are listed in Table 4 below. Table 4 - 25 wt% Regrind Blends

[0113] A review of table 4 reveals that the molecular weight retention was over 91 % for a blend with 25 wt% of Ex. 20 (that was subjected to 10 regrinding passes through an extruder).

[0114] made using a 1.5” Killion single screw extruder having a 30:1 L / D. The vent location was 2 / 3 down the barrel at zone 3 location. The material was extruded at either 20, 40, or 60 rpms that represented outputs of 15, 25 and 30 Ibs / hr. Samples were extruded through a single hole die having a 1 / 8thdie opening onto a moving belt where they were air cooled and pelletized. Initial moisture content was measured before feeding the material to the extruder and then samples were collected and moisture content on the extruded samples were tested and compared to the initial moisture content for various process configurations.Examples 41-50 (Plasticizer Retention)

[0115] Samples were dried in a desiccant drying system at 60°C for 8 hours prior to extruding. Dried samples were extruded using a 30 mm Sterling single screw extruder to make regrind pellets. The material received multiple passes through the extruder to represent a regrind process for thermoformed articles where trim scrap can be chopped up, re-pelletized and blended back with virgin feed pellets. Materials were melt compounded at temps of 210 to 240C and pelletized. The plasticizer content was measured for the control (C-1 ) with no regrind and after each pass of regrind material. The results for 10 passes of regrind pellets are listed in Table 5 below.Table 5 - Multiple Pass for Single Screw Extruder

[0116] A review of table 5 reveals that the plasticizer retention was over 90% after 10 passes through the extruder. Examples 51-60 (Multiple Pass Blends with 75% Virgin)

[0117] Samples from examples 11 -20 were then blended 25 wt% with virgin resin at 75 wt% and 0.5 mm films were extruded on a 38 mm single screw Killion extruder. The films were extruded at zone temps from 210-230°C, 56 rpm, and the films were cast onto an S-roll roll configuration having a roll temperature of 93°C. The Tg was measured for the control (C-1) with no regrind and after each pass with 25 wt% regrind material. The results for 10 blends of regrind films are listed in Table 6 below.Table 6 - 25 wt% Regrind Blends

[0118] A review of table 6 reveals that the Tg increased by 3.1 °C for a blend with 25 wt% of Ex. 20 (that was subjected to 10 regrinding passes through an extruder).Examples 61-70 (Multiple Pass Blends with 50% Virgin)

[0119] Samples from examples 11 -20 were then blended 50 wt% with virgin resin at 50wt% and 0.5 mm films were extruded on a 38 mm single screw Killion extruder. The films were extruded at zone temps from 210-230°C, 56 rpm, and the films were cast onto an S-roll roll configuration having a roll temperature of 93°C. The Tg was measured for the control (C-1) with no regrind and after each pass with 50 wt% regrind material. The results for 10 blends of regrind films are listed in Table 7 below.Table 7 - 50 wt% Regrind Blends

[0120] A review of table 7 reveals that the Tg increased by less than 5°C for blend with 50 wt% of the regrind (that was subjected to up to 10 regrinding passes through an extruder).Examples - Foamed Sheet

[0121] The following examples illustrate how cellulose ester-based materials can be melt processed in a foam extrusion line with the inclusion of varying amounts of reground material that was already melt processed, while retaining acceptable properties for the final melt processed foamed material.

[0122] The material was foamed on a tandem foam line. The line was configured with A Krauss-Maffei 30mm twin screw coupled to a 60mm Krauss-Maffei single screw. Materials were extruded at 200 to 220°C on the single screw followed by cooling to 175 to 190°C in the cooling extruder. Blowing agent was injected into the twin screw about half-way down the barrel and the material was foamed through an annular die.Examples 71-75 (Multiple Pass Blends with 50% Virgin)

[0123] Samples from examples 12, 14, 16, 18 and 20 were then blended 50 wt% with virgin resin at 50wt% and foam sheets were made. The color molecular weight, density, and thickness were measured for the control (C-1) with no regrind and after each pass with 50 wt% regrind material. The results for 5 blends of regrind films are listed in Tables 8 and 9 below.Table 8 - 50 wt% Regrind Blends

[0124] A review of table 8 reveals that the color did not significantly change for the foamed sheet made using blends with 50 wt% regrind (that were subjected up to 10 regrinding passes through an extruder).Table 9 - 50 wt% Regrind Blends

[0125] A review of table 9 reveals that the molecular weight retention was over 87% for a blend with 50 wt% of Ex. 20 (that was subjected to 10 regrinding passes through an extruder).Examples - Extruded Film Color Testing

[0126] The following examples illustrate how cellulose ester-based materials can be melt processed with the inclusion of varying amounts of reground material that was already melt processed, while retaining acceptable color properties for the final melt processed film.

[0127] Films having a thickness of 0.5 mm were extruded on a 38 mm single screw Killion extruder. The films were extruded at zone temps from 210-230°C, 56 rpm, and the films were cast onto an S-roll roll configuration having a roll temperature of 93°C. The color was measured for the control (C-1 ) with no regrind and after each pass with 50 wt% and 25wt% regrind material, respectively. The results for 10 blends of regrind films are listed in Tables 10 and 11 below.Examples 76-85 (Multiple Pass Blends with 50% Virgin)

[0128] Samples from examples 11 -20 were blended 50 wt% with virgin resin at 50wt% and films were made. The color was measured for the control (C-1 ) with no regrind and after each pass with 50 wt% regrind material. The results for 10 blends of regrind films are listed in Table 10 below.Table 10 - 50 wt% Regrind Blends

[0129] A review of table 10 reveals that the color did not significantly change for the foamed sheet made using blends with 50 wt% regrind (that were subjected up to 10 regrinding passes through an extruder). Examples 86-95 (Multiple Pass Blends with 25% Virgin)

[0130] Samples from examples 11 -20 were blended 25 wt% with virgin resin at 75 wt% and films were made. The color was measured for the control (C-1 ) with no regrind and after each pass with 25 wt% regrind material. The results for 10 blends of regrind films are listed in Table 11 below.Table 11 - 25 wt% Regrind Blends

[0131] A review of table 11 reveals that the color did not significantly change for the foamed sheet made using blends with 25 wt% regrind (that were subjected up to 10 regrinding passes through an extruder).Comparative Examples - Molecular Weight Retention

[0132] The following comparative examples illustrate how certain cellulose ester-based materials that are melt processed with the inclusion of varying amounts of reground material that was already melt processed, effect the molecular weight.

[0133] The material used in the comparative examples was Eastman CA 398-30, which is a CDA, that was compounded with a 20 wt% target amount of triacetin plasticizer. This CDA had a target acetyl degree of substitution of 2.45, stabilized with metals M in an amount lower than 120 ppm M, and had a heated IV or 0.732 dL / g.

[0134] Test samples were made to study the effect of various amounts of regrind on molecular weight when melt processing in a single screw extruder.Comparative Examples C1-C10 (Multiple Pass 100% Regrind)

[0135] Samples were dried in a desiccant drying system prior to extruding. Dried samples were extruded using a 30 mm Sterling single screw extruder to make regrind pellets. The material received multiple passes through the extruder to represent a regrind process for thermoformed articles where trim scrap can be chopped up, re-pelletized and blended back with virgin feed pellets. Materials were melt compounded at temps of 210 to 240C and pelletized. The molecular weight was measured for the control (C-2) with no regrind and after each pass of regrind material. The results for 10 passes of regrind pellets are listed in Table 12 below and a comparison to with Examples 11-20 are shown in Table 13.Table 12 - Multiple Pass for Single Screw Extruder

[0136] A review of table 2 reveals that the molecular weight retention was over 80% after 10 passes through the extruder.Table 13 - Multiple Pass for Single Screw Extruder

[0137] A review of table 13 reveals that the molecular weight was higher for Examples 11-22 compared to Comparative Examples C1-C10 and that the percent difference in molecular weight increased with number of passes through the extruder.DEFINITIONS

[0138] It should be understood that the following is not intended to be an exclusive list of defined terms. Other definitions may be provided in the foregoing description, such as, for example, when accompanying the use of a defined term in context.

[0139] As used herein, the terms “a,” “an,” and “the” mean one or more.

[0140] As used herein, the terms “comprising,” “comprises,” and “comprise” are open-ended transition terms used to transition from a subject recited before the term to one or more elements recited after the term, where the element or elements listed after the transition term are not necessarily the only elements that make up the subject.

[0141] To be considered “compostable,” a material must meet the following four criteria: (1 ) the material should pass biodegradation requirement in a test under controlled composting conditions at elevated temperature (58°C) according to ISO 14855-1 (2012) which correspond to an absolute 90% biodegradation or a relative 90% to a control polymer, (2) the material tested under aerobic composting condition according to ISO16929 (2013) must reach a 90% disintegration ; (3) the test material must fulfill all the requirements on volatile solids, heavy metals and fluorine as stipulated by ASTM D6400 (2012), EN 13432 (2000) and ISO 17088 (2012); and (4) the material should not cause negative on plant growth.

[0142] As used herein, the term “biodegradable” generally refers to the biological conversion and consumption of organic molecules. Biodegradability is an intrinsic property of the material itself, and the material can exhibit different degrees of biodegradability, depending on the specific conditions to which it is exposed. The term “disintegrable” refers to the tendency of a material to physically decompose into smaller fragments when exposed to certain conditions. Disintegration depends both on the material itself, as well as the physical size and configuration of the article being tested. Ecotoxicity measures the impact of the material on plant life, and the heavy metal content of the material is determined according to the procedures laid out in the standard test method.

[0143] To be considered “biodegradable,” under home composting conditions according to the French norm NF T 51-800 and the Australian standard AS 5810, a material must exhibit a biodegradation of at least 90 percent in total (e.g., as compared to the initial sample), or a biodegradation of at least 90 percent of the maximum degradation of a suitable reference material after a plateau has been reached for both the reference and test item. The maximum test duration for biodegradation under home compositing conditions is 1 year.

[0144] To be considered “biodegradable,” under industrial composting conditions according to ASTM D6400 and ISO 17088, at least 90 percent of the organic carbon in the whole item (or for each constituent present in an amount of more than 1 % by dry mass) must be converted to carbon dioxide by the end of the test period when compared to the control or in absolute. According to European standard ED 13432 (2000), a material must exhibit a biodegradation of at least 90 percent in total, or a biodegradation of at least 90 percent of the maximum degradation of a suitable reference material after a plateau has been reached for both the reference and test item. The maximum test duration for biodegradability under industrial compositing conditions is 180 days.

[0145] In order to be considered “biodegradable,” under soil composting conditions according the OK biodegradable SOIL conformity mark of Vingotte and the DIN Gepruft Biodegradable in soil certification scheme of DIN CERTCO, a material must exhibit a biodegradation of at least 90 percent in total (e.g., as compared to the initial sample), or a biodegradation of at least 90 percent of the maximum degradation of a suitable reference material after a plateau has been reached for both the reference and test item. The maximum test duration for biodegradability under soil compositing conditions is 2 years.

[0146] Unless specified otherwise, as used herein the absolute “Weight Average Molecular Weight” (or Mw) for cellulose esters is determined by GPC Analysis with the following parameters: Solvent: Tetrahydrofuran stabilized with BHT Preservative; Temperature: 30° C; Flow rate: 1.0 ml / min; Sample solution: 25 mg Cellulose Ester in 10 ml Tetrahydrofuran with BHT preservative + 10 pl toluene flow rate marker; Injection volume: 50 pl; Column set: PolymerLaboratories 5 pm PLgel, Guard + Mixed C + Oligopore; Detection: Refractive Index; Calibrants: monodisperse polystyrene standards, MW = 580 to 3,220,000 from Polymer Laboratories; Universal calibration parameters: PS - K = 0.0001280 and a = 0.7120, and CA - K = 0.00007572 and a = 0.8424. The universal calibration parameters above were determined by light scattering and viscometery to yield the correct weight average molecular weights.ADDITIONAL EMBODIMENTS

[0147] In one embodiment or in combination with any of the embodiments mentioned herein, the biodegradable cellulose acetate foam or rigid article is industrial compostable or home compostable. In one subclass of this class, the foam or rigid article is industrial compostable. In one sub-subclass of this subclass, the foam or rigid article has a thickness that is less than 6 mm. In one sub-subclass of this subclass, the foam or rigid article has a thickness that is less than 3 mm. In one sub-subclass of this subclass, the foam or rigid article has a thickness that is less than 1.1 mm. In one subclass of this class, the foam or rigid article is home compostable. In one sub-subclass of this subclass, the foam or rigid article has a thickness that is less than 6 mm. In one sub-subclass of this subclass, the foam or rigid article has a thickness that is less than 3 mm. In one sub-subclass of this subclass, the foam or rigid article has a thickness that is less than 1.1 mm. In one sub-subclass of this subclass, the foam or rigid article has a thickness that is less than 0.8 mm. In one sub-subclass of this subclass, the foam or rigid article has a thickness that is less than 0.6 mm. In one sub-subclass of this subclass, the foam or rigid article has a thickness that is less than 0.4 mm.

[0148] In one embodiment or in combination with any of the embodiments mentioned herein, the thickness of the foam or rigid article is from 1 to 10 mm, from 1 to 8 mm, from 2 to 8 mm, from 3 to 7 mm, from 4 to 6 mm, about 4 mm, about 5 mm, about 6 mm, about 7 mm, or about 8 mm. However, it should be noted that the foam or rigid article may have other, larger sizes. For example, in some embodiments, the foam or rigid article may have a thickness from 0.5 to 24 inches, from 1 to 15 inches, or 3 to 12 inches.

[0149] In one embodiment or in combination with any of the embodiments mentioned herein, the foam or rigid article exhibits greater than 90% disintegration after 12 weeks according to the disintegration test protocol for films, as described in the specification.

[0150] The compositions used to prepare the biodegradable cellulose acetate foams can comprise other additives such as fillers, stabilizers, odor modifiers, waxes, compatibilizers, biodegradation promoters, dyes, pigments, colorants, lubricants, anti-oxidants, viscosity modifiers, antifungal agents, heat stabilizers, antibacterial agents, softening agents, mold release agents, UV absorbers, and combinations thereof. Each additional additive may be present in the cellulose ester-based material in an amount less than 10 wt. %, less than 5 wt. % less than 4 wt. %, less than 3 wt. %, less than 2 wt. %, or less than 1 .0 wt. %. It should be noted that the same type of compounds or materials can be identified for or included in multiple categories of components in the cellulose acetate compositions. For example, polyethylene glycol (PEG) could function as a plasticizer or as an additive that does not function as a plasticizer, such as a hydrophilic polymer or biodegradation promotor, e.g., where a lower molecular weight PEG has a plasticizing effect and a higher molecular weight PEG functions as a hydrophilic polymer but without plasticizing effect.

[0151] In any of the embodiments for the melt composition, the recycled cellulose ester material can comprise industrial scrap material. The industrial scrap material can comprise trim scrap. The recycled cellulose ester material can comprise post-consumer material.

[0152] The cellulose ester in the virgin cellulose ester feedstock and / or the recycled cellulose ester material can have a degree of substitution of acetyl (DSAC) between 2.2 to 2.8. The cellulose ester can be cellulose diacetate. The cellulose ester (e.g., cellulose diacetate) in the virgin cellulose ester material and / or the recycled cellulose ester material can have a metals-to-sulfur molar ratio (M / S) of from 1.35 to 10.0. The virgin cellulose ester feedstock can have a molecular weight in a range from 50,000 to 250,000, from 60,000 to 200,000, from 70,000 to 160,000, from 80,000 to 150,000, from 90,000 to 100,000, or from 90,000 to 95,000 Daltons.

[0153] The cellulose ester (e.g., cellulose diacetate) in the virgin cellulose ester material and / or the recycled cellulose ester material can be a biodegradable, melt-stable cellulose ester (e.g., cellulose diacetate) that is stabilized with a metal M selected from the group consisting of calcium, magnesium, potassium, sodium and combinations thereof. The cellulose ester can be stabilized with Na. The cellulose ester can be stabilized with metal M, wherein M is present in an amount of at least 120 ppm, or at least 130 ppm, or at least 140 ppm, or at least 150 ppm, or 120 to 300 ppm, or 130 to 300 ppm, or 140 to 300 ppm, or 150 to 300 ppm, or 120 to 250 ppm, or 130 to 250 ppm, or 140 to 250 ppm, or 150 to 250 ppm, or 120 to 200 ppm, or 130 to 200 ppm, or 140 to 200 ppm, or 150 to 200 ppm (based on the weight of the cellulose ester). Metal content can be determined by digesting the cellulose ester in nitric acid on a hot plate, diluting the fully digested sample to a final solution of 10 % nitric acid in water and analyzing for metal content using ICP-OES. In embodiments, M is Na.

[0154] The cellulose ester (e.g., cellulose diacetate) in the virgin cellulose ester material and / or the recycled cellulose ester material can be a biodegradable, melt-stable cellulose acetate characterized by a metals-to- sulfur molar ratio M / S of at least 1 .3, or at least 1 .35, wherein the M is the molar sum of metals selected from the group consisting of calcium, magnesium, potassium, sodium and combinations thereof and S is moles sulfur.

[0155] The cellulose ester (e.g., cellulose diacetate) in the virgin cellulose ester material and / or the recycled cellulose ester material can be a biodegradable melt-stable cellulose acetate characterized by a heated intrinsic viscosity (HIV) of at least 0.9.

[0156] In another aspect, the cellulose acetate melt, that comprises both virgin cellulose ester material and / or the recycled cellulose ester material, can include i) a biodegradable, melt-stable cellulose acetate characterized by a metals-to-sulfur molar ratio M / S of at least 1 .3, or at least 1 .35, wherein the M is the molar sum of metals selected from the group consisting of calcium, magnesium, potassium, sodium and combinations thereof and S is moles sulfur; and (ii) a plasticizer.

[0157] The cellulose acetate melt, that comprises both virgin cellulose ester material and / or the recycled cellulose ester material, can include i) a biodegradable melt-stable cellulose acetate characterized by a heated intrinsic viscosity (HIV) of at least 0.9; and (ii) a plasticizer.

[0158] In yet another aspect, the melt-formed article can be formed from a cellulose acetate melt that includes i) a biodegradable, melt-stable cellulose acetate characterized by a heated intrinsic viscosity (HIV) of at least 0.9 and (ii) a plasticizer.

[0159] The melt-formed article can be formed from a cellulose acetate melt that includes i) a biodegradable, melt-stable stabilized cellulose acetate characterized by a metals-to-sulfur molar ratio M / S of at least 1.3, or at least 1.35, wherein the M is the molar sum of metals selected from the group consisting of calcium, magnesium, potassium, sodium and combinations thereof and S is moles sulfur; and (ii) a plasticizer.

[0160] In one or more embodiments or aspects, the biodegradable cellulose acetates in the virgin cellulose ester material and / or the recycled cellulose ester material may be characterized by a heated intrinsic viscosity (also referred to herein as HIV) of at least 0.9 or at least 1 .0 or at least 1 .05 or at least 1.1 or at least 1.15 or at least 1.2 or at least 1.25 or at least 1.3 or at least 1.35 or at least 1 .4 or at least 1 .45 or at least 1 .5 or at least 1 .55 or at least 1 .6 or at least 1.65. In one or more embodiments, melt-processable, biodegradable cellulose acetates of the present invention may be characterized by a heated intrinsic viscosity (HIV) of between 1.0 and 2.0 or between 1.1 and 1.8 or between 1.15 and 1.75 or between 1.15 and 1.7 or between 1.2 and 1.7. In embodiments, the melt-processable, biodegradable cellulose acetate has an HIV in a range from 1 .15 to 1 .7, or 1 .2 to 1.7, or 1.25 to 1.7, or 1.3 to 1.7. Heated intrinsic viscosity, in general, is a parameter used in the art to characterize a material’s melt flow characteristics. HIV may be measured in a method similar to ASTM method D 871-91 but with a heated protocol. In such a protocol, a weighed amount of sample is heat treated at an initial heat temperature of 50 °C and held for 3 minutes. The temperature is then ramped at a rate of 20 degrees per minute (DPM) until 250 °C is reached and held for 3 minutes. Post treatment,the sample is allowed to cool and then added to acetone to form solution having a concentration of 0.50 g / dL. The relative viscosity is then measured using the solution at 30 °C using a Viscotek Y501 C automated viscometer and the intrinsic viscosity is calculated using the Solomon-Gatesman equation with units of dL / g.

[0161] In one or more embodiments or aspects, the cellulose ester melt composition comprises cellulose acetates that may be characterized by a heated intrinsic viscosity (also referred to herein as HIV) of at least 0.9 or at least 1 .0 or at least 1 .05 or at least 1.1 or at least 1 .15 or at least 1 .2 or at least 1 .25 or at least 1 .3 or at least 1 .35 or at least 1 .4 or at least 1 .45 or at least 1 .5 or at least 1.55 or at least 1.6 or at least 1.65. In one or more embodiments, melt-processable, biodegradable stabilized cellulose acetates of the present invention may be characterized by a heated intrinsic viscosity (HIV) of between 1 .0 and 2.0 or between 1 .1 and 1 .8 or between 1.15 and 1 .75 or between 1.15 and 1.7 or between 1.2 and 1.7. In embodiments, the melt-processable, biodegradable stabilized cellulose acetate has an HIV in a range from 1.15 to 1.7, or 1.2 to 1.7, or 1.25 to 1.7, or 1.3 to 1.7. Heated intrinsic viscosity, in general, is a parameter used in the art to characterize a material’s melt flow characteristics. HIV may be measured according to the method described above.

[0162] The plasticizer can be present in the melt resin in an amount from 2 to 40 wt. %, or 2 to 30 wt%, or 2 to 25 wt%, or 5 to 40 wt. %, or 5 to 30 wt%, or 5 to 25 wt%, or 10 to 40 wt. %, or 10 to 30 wt%, or 10 to 25 wt%, or 15 to 40 wt. %, or 15 to 30 wt%, or 15 to 25 wt%. The plasticizer can comprise triacetin. The melt composition can comprise a nucleating agent. The nucleating agent can comprise a physical nucleating agent and / or a chemical blowing agent. The physical nucleating agent can comprise talc. The melt composition can comprise a blowing agent. The blowing agent can comprise a chemical blowing agent. The chemical blowing agent can comprise sodium bicarbonate and / or citric acid. The chemical blowing agent can comprise a combination of two or more different types of chemical blowing agents. The blowing agent can comprise a physical blowing agent. The physical blowing agent can compriseC02 or N2. The physical blowing agent can comprise one or more hydrocarbons. The physical blowing agent can comprise one or more organic compounds having a boiling point below the melt temperature of the melt composition. The one or more organic compounds can be chosen from ketones, alcohols, ethers, esters, glycol ethers, paraffins, glycol ether esters, or combinations thereof. The blowing agent can comprise a combination of physical blowing agents and chemical blowing agents.

[0163] The melt composition can further comprise one or more additional additives. The additional additives can comprise molecular weight enhancers. The molecular weight enhancers can have a molecular weight from 150,000 to 250,000 Daltons. The molecular weight enhancers can be passive enhancers. The passive enhancers can comprise ultra-high molecular weight cellulose acetates. The molecular weight enhancers can be reactive enhancers. The reactive enhancers comprise chain extenders. The chain extenders comprise multifunctional epoxides. The chain extenders comprise multifunctional isocyanates. The chain extenders comprise acrylates. The chain extenders comprise JONCRYL chain extenders. The additional additives can comprise fillers. The fillers can comprise talc, CaCO3, cellulose fibers, mica, Ti02, clay, silica, starch, kaolin, wollastonite, zeolites, glass fibers or combinations thereof. The fillers can comprise inorganic particulates. The fillers can comprise talc.The fillers comprise CaCO3. The additional additives can comprise a stabilizer. The additional additives can comprise a color stabilizer. The color stabilizer can comprise one or more stabilizers chosen from citric acid, acetic acid, propionic acid, butyric acid, valeric acid, tartaric acid, oxalic acid, malic acid, benzoic acid, formate, acetate, propionate, butyrate, valerate citrate, tartarate, oxalate, malate, maleic acid, maleate, phthalic acid, phthalate, benzoate, and combinations thereof. The additional additives can comprise a UV absorber. The additional additives can comprise an antioxidant. The additional additives can comprise an acid scavenger. The additional additives can comprise an odor modifier. The additional additives can comprise a colorant. The additional additives can be present in the (particulate) material in an amount less than 10wt. %, less than 5 wt. % less than 4 wt. %, less than 3 wt. %, less than 2 wt. %, or less than 1 .0 wt. %.

[0164] In embodiments, when the melt composition is formed into a test film according to the Film Forming Procedure described herein (in the specification), the test film can exhibit a AE color difference of less than 3 units with respect to a control film formed according to the Film Forming Procedure (described in the specification), with the control film formed from virgin cellulose ester feedstock and no recycled cellulose ester material, wherein the AE color difference is defined by the equation: AE =[(Aa*)2+(Ab*)2+(AL*)2]1 / 2, wherein a*, b*, and L* are CIE 1976 color space values measured according to ASTM 2244.

[0165] In an aspect, an extruded article can be formed from the melt composition. The extruded article can be a foamed article. The extruded article can be thermoformed. The extruded article can be a film. The extruded article can be a fiber. The extruded article can be a molded article. The extruded article can include an extrusion profile. The extruded article can further comprise or can be incorporated into a laminated article. The laminated article can be a press laminated article.

[0166] In other aspects, injection molded articles can be formed from the melt composition. Articles can be made by compression molding. Articles can be made via a lamination process.

[0167] In another aspect, a process for forming a cellulose ester article is provided, wherein the process comprises the following steps: (a) obtaining cellulose ester scrap material; (b) regrinding the cellulose ester scrap material to form a reground scrap material that is particulated; (c) removing moisture from the reground scrap material; (d) obtaining cellulose ester virgin feedstock, wherein the virgin feedstock is a formulated feedstock comprising a cellulose ester and a plasticizer; (e) removing moisture from the virgin feedstock; and (f) combining the reground scrap material and the virgin feedstock to form a cellulose ester melt composition. The cellulose ester melt composition formed by this process can include any of the melt compositions discussed herein.

[0168] For the removing moisture of step (c), the reground scrap material can have a moisture content of less than 3000 ppm. After the removingmoisture of step (e), the virgin feedstock can have a moisture content of less than 1000 ppm. The scrap material can be industrial trim scrap. The trim scrap can be obtained from thermoforming. The trim scrap can be obtained from injection molding. The scrap material can be post-consumer scrap. The scrap material is a foamed material. The scrap material can have density of less than 0.5 g / cc. The regrinding of step (b) can include densifying the scrap material. The densified reground scrap material can have a density of more than 0.4, or more than 0.5 g / cc. The melt composition can comprise at least ten percent (10%) scrap material.

[0169] The scrap material can be less dense than the virgin feedstock. The virgin feedstock can have a density of 1.3 g / cc. The virgin feedstock can comprise pellets. The scrap material can have a density of less than 0.3 g / cc. The reground scrap material can have a density of more than 0.4 or more than 0.5 g / cc. The reground scrap material can have a density from 0.4 to 1 .3 g / cc, from 0.5 to 1 .3 g / cc, from 0.5 to 1 .0 g / cc, from 0.5 to 0.9 g / cc, from 0.5 to 0.8 g / cc, and / or between 0.5 to 0.7 g / cc. The virgin feedstock can be formed with regular shapes, and the reground scrap material can have irregular shapes. The reground scrap material can be shaped as flakes. The flakes of the reground scrap material can have thicknesses up to 200 mils, or up to 100 mils, with a density of 0.04 - 1.3 g / cc, or 0.04 - 1.0 g / cc, or 0.04 - 0.7 g / cc. The reground scrap material can be densified during the regrinding of step (b). The flakes of the reground scrap material can have thicknesses up to 100 mils, with a density of 0.3 - 0.7 g / cc. The reground scrap material can be densified during the regrinding of step (b), wherein the flakes of the reground scrap material have thicknesses up to 40 mils thick, with a density of 0.7-1.0 g / cc. The reground scrap material can be densified during the regrinding of step (b), wherein the flakes of the reground scrap material have thicknesses up to 20 mils thick, with a density of 1 .0 - 1 .3 g / cc.

[0170] The reground scrap material can be densified during the regrinding of step (b), or the scrap material can be a rigid material. The regrinding of step (b) can include processing the scrap material through a grinding machine or a shredding machine. The regrinding of step (b) can include processing the scrapmaterial through an extruder. The extruder can be a single-screw extruder. The extruder can be a twin-screw extruder. The regrinding of step (b) can include processing the scrap material through a pellet mill. The regrinding of step (b) can include densifying the scrap material, wherein the scrap material is densified in an extruder or a pellet mill. The drying of step (c) can be performed in an extruder or a pellet mill. The drying of step (c) can include densifying the scrap material. The drying of step (c) can be performed separately from the regrinding of step (b). The drying of step (c) can include processing the reground scrap material in an inert atmosphere. The drying of step (c) can be performed using a drying system. The drying system can be a hot-air desiccant drying system. The scrap material can have less plasticizer, on a total weight basis, than the virgin feedstock. The scrap material can comprise one or more nucleating agents. The scrap material can comprise one or more blowing agents.

[0171] The process can further include the step of adding a color stabilizer to form the melt composition. The color stabilizer can comprise citric acid. The color stabilizer comprises phosphite. The color stabilizers can be selected from one or more of the following: acetic acid, propionic acid, butyric acid, valeric acid, tartaric acid, oxalic acid, malic acid, benzoic acid, formate, acetate, propionate, butyrate, valerate citrate, tartarate, oxalate, malate, maleic acid, maleate, phthalic acid, phthalate, benzoate, and combinations thereof.

[0172] The process can further include the step of extruding the melt composition to form a sheet. The process can further include the step of capturing plasticizer lost during the extruding step. The process can further include the step of re-introducing the captured plasticizer into the melt composition. The captured plasticizer can be re-introduced into the scrap material during the regrinding and / or drying of steps (b) and / or (c). The captured plasticizer can be re-introduced into the melt composition during the combining of step (f).

[0173] The cellulose ester article can be a foamed article. The article can be thermoformed. The article can be an extruded article. The extruded article can be a film. The extruded article can be a fiber. The extruded article can bea molded article. The extruded article can include an extrusion profile. The extruded article can further comprise or can be incorporated into a laminated article. The laminated article can be a press laminated article. The cellulose ester article can be an injection molded article.

[0174] In any of the embodiments for the melt composition, in addition to the CE, e.g., biodegradable cellulose diacetate, the melt composition can comprise one or more antioxidants. In embodiments, the one or more antioxidants can be present in amounts sufficient to be effective as a color stabilizer to stabilize color during melt processing, storage and / or use of an article made from the melt composition. Antioxidants can be classified into several classes, including primary antioxidant, and secondary antioxidant. Primary antioxidants are generally known to function essentially as free radical terminators (scavengers). Secondary antioxidants are generally known to decompose hydroperoxides (ROOH) into nonreactive products before they decompose into alkoxy and hydroxy radicals. Secondary antioxidants are often used in combination with free radical scavengers (primary antioxidants) to achieve a synergistic inhibition effect and secondary AOs are used to extend the life of phenolic type primary AOs.

[0175] “Primary antioxidants” are antioxidants that act by reacting with peroxide radicals via a hydrogen transfer to quench the radicals. Primary antioxidants generally contain reactive hydroxy or amino groups such as in hindered phenols and secondary aromatic amines. Examples of primary antioxidants include BHT, Irganox™ 1010, 1076, 1726, 245, 1098, 259, and 1425; Ethanox™ 310, 376, 314, and 330; Evernox™ 10, 76, 1335, 1330, 3114, MD 1024, 1098, 1726, 120. 2246, and 565; Anox™ 20, 29, 330, 70, IC-14, and 1315; Lowinox™ 520, 1790, 22IB46, 22M46, 44B25, AH25, GP45, CA22, CPL, HD98, TBM-6, and WSP; Naugard™ 431 , PS48, SP, and 445; Songnox™ 1010, 1024, 1035, 1076 CP, 1135 LQ, 1290 PW, 1330FF, 1330PW, 2590 PW, and 3114 FF; and ADK Stab AO-20, AO-30, AO-40, AO-50, AO-60, AO-80, and AO-330.

[0176] “Secondary antioxidants” are often called hydroperoxide decomposers. They act by reacting with hydroperoxides to decompose theminto nonreactive and thermally stable products that are not radicals. They are often used in conjunction with primary antioxidants. Examples of secondary antioxidants include the organophosphorous (e.g., phosphites, phosphonites) and organosulfur classes of compounds. The phosphorous and sulfur atoms of these compounds react with peroxides to convert the peroxides into alcohols. Examples of secondary antioxidants include Ultranox 626, Ethanox™ 368, 326, and 327; Doverphos ™ LPG11 , LPG12, DP S-680, 4, 10, S480, S-9228, S- 9228T; EvernoxTM168 and 626; Irgafos™ 126 and 168; Weston™ DPDP, DPP, EHDP, PDDP, TDP, TLP, and TPP; Mark™ CH 302, CH 55, TNPP, CH66, CH 300, CH 301 , CH 302, CH 304, and CH 305; ADK Stab 2112, HP- 10, PEP-8, PEP-36, 1178, 135A, 1500, 3010, C, and TPP; Weston 439, DHOP, DPDP, DPP, DPTDP, EHDP, PDDP, PNPG, PTP, PTP, TDP, TLP, TPP, 398, 399, 430, 705, 705T, TLTTP, and TNPP; Alkanox 240, 626, 626A, 627AV, 618F, and 619F; and Songnox™ 1680 FF, 1680 PW, and 6280 FF.

[0177] In embodiments, the melt composition comprises at least one stabilizer, wherein the stabilizer comprises one or more secondary antioxidants or one or more primary antioxidants. In embodiments, the stabilizer comprises a first stabilizer component chosen from one or more secondary antioxidants and a second stabilizer component chosen from one or more primary antioxidants, citric acid or a combination thereof.

[0178] In embodiments, the stabilizer comprises one or more primary antioxidants in an amount in the range of from 0.01 to 0.8, or 0.01 to 0.7, or 0.01 to 0.5, or 0.01 to 0.4, or 0.01 to 0.3, or 0.01 to 0.25, or 0.01 to 0.2, or 0.05 to 0.8, or 0.05 to 0.7, or 0.05 to 0.5, or 0.05 to 0.4, or 0.05 to 0.3, or 0.05 to 0.25, or 0.05 to 0.2, or 0.08 to 0.8, or 0.08 to 0.7, or 0.08 to 0.5, or 0.08 to 0.4, or 0.08 to 0.3, or 0.08 to 0.25, or 0.08 to 0.2, in weight percent of the total amount of primary antioxidants based on the total weight of the composition. In one subclass of this class, the stabilizer comprises one or more primary antioxidants and citric acid in the amounts discussed herein.

[0179] In embodiments, the stabilizer comprises one or more secondary antioxidants in an amount in the range of from 0.01 to 0.8, or 0.01 to 0.7, or 0.01 to 0.5, or 0.01 to 0.4, or 0.01 to 0.3, or 0.01 to 0.25, or 0.01 to 0.2, or 0.05to 0.8, or 0.05 to 0.7, or 0.05 to 0.5, or 0.05 to 0.4, or 0.05 to 0.3, or 0.05 to 0.25, or 0.05 to 0.2, or 0.08 to 0.8, or 0.08 to 0.7, or 0.08 to 0.5, or 0.08 to 0.4, or 0.08 to 0.3, or 0.08 to 0.25, or 0.08 to 0.2, in weight percent of the total amount of secondary antioxidants based on the total weight of the composition. In one class of this embodiment, the stabilizer comprises a secondary antioxidant that is a phosphite compound. In one class of this embodiment, the stabilizer comprises a secondary antioxidant that is a phosphite compound and another secondary antioxidant that is DLTDP.

[0180] In one subclass of this class, the stabilizer further comprises a second stabilizer component that comprises one or more primary antioxidants in an amount in the range of from 0.05 to 0.7, or 0.05 to 0.6, or 0.05 to 0.5, or 0.05 to 0.4, or 0.05 to 0.3, or 0.1 to 0.6, or 0.1 to 0.5, or 0.1 to 0.4, or 0.1 to 0.3, in weight percent of the total amount of primary antioxidants based on the total weight of the composition. In another subclass of this class, the stabilizerfurther comprises a second stabilizer component that comprises citric acid in an amount in the range of from 0.05 to 0.2, or 0.05 to 0.15, or 0.05 to 0.1 in weight percent of the total amount of citric acid based on the total weight of the composition. In another subclass of this class, the stabilizer further comprises a second stabilizer component that comprises one or more primary antioxidants and citric acid in the amounts discussed herein. In one subclass of this class, the stabilizer comprises less than 0.1 wt% or no primary antioxidants, based on the total weight of the composition. In one subclass of this class, the stabilizer comprises less than 0.05 wt% or no primary antioxidants, based on the total weight of the composition.

[0181] In one embodiment or in combination with any other embodiment mentioned herein, the foam, composition, foamable composition, or rigid composition further comprises a photodegradation catalyst. In one class of this embodiment, the photodegradation catalyst is a titanium dioxide, or an iron oxide. In one subclass of this class, the photodegradation catalyst is a titanium dioxide. In one subclass of this class, the photodegradation catalyst is an iron oxide.

[0182] In one embodiment or in combination with any other embodiment mentioned herein, the foam, composition, foamable composition, or rigid composition further comprises a pigment. In one class of this embodiment, the pigment is a titanium dioxide, a carbon black, or an iron oxide. In one subclass of this class, the pigment is a titanium dioxide. In one subclass of this class, the pigment is a carbon black. In one subclass of this class, the pigment is an iron oxide. In one subclass of this class, the pigment is a biodegradable particulate natural filler.CLAIMS NOT LIMITED TO DISCLOSED EMBODIMENTS

[0183] The preferred forms of the invention described above are to be used as illustration only and should not be used in a limiting sense to interpret the scope of the present invention. Modifications to the exemplary embodiments, set forth above, could be readily made by those skilled in the art without departing from the spirit of the present invention.

[0184] The inventors hereby state their intent to rely on the Doctrine of Equivalents to determine and assess the reasonably fair scope of the present invention as it pertains to any apparatus not materially departing from but outside the literal scope of the invention as set forth in the following claims.

Claims

CLAIMSWhat is claimed is:

1. A melt composition comprising: a virgin cellulose ester feedstock, wherein the virgin cellulose ester feedstock is a formulated feedstock comprising virgin cellulose ester and a plasticizer; and at least ten percent (10%) recycled cellulose ester material, as measured based on the total weight of the melt composition, wherein the recycled cellulose ester material comprises one or more of the following: i) cellulose ester having a molecular weight (Mw) less than the Mw of the virgin cellulose ester in the feedstock; ii) a plasticizer content lower than the plasticizer content of the feedstock; and / or iii) a glass transition temperature (Tg) higher than the Tg of the feedstock; and wherein the melt composition has one or more of the following: a) a molecular weight (Mw) within seventy-five percent (75%) of a molecular weight (Mw) of the virgin cellulose ester feedstock; b) a plasticizer content within eighty-five percent (85%) of a plasticizer content of the virgin cellulose ester feedstock; and / or c) a glass transition temperature (Tg) that is equal to or higher than a glass transition temperature (Tg) of the virgin cellulose ester feedstock.

2. The composition according to claim 1 , wherein the melt composition is biodegradable.

3. The composition according to claim 1 or 2, the melt composition comprises at least 15%, at least 20%, at least 25%, at least 30%, at least 35%, at least 40%, at least 45%, at least 50%, at least 55%, at least 60%, at least 65%, and / or at least 70% recycled cellulose ester material.

4. The composition according to any one of claims 1 to 3, wherein the molecular weight (Mw) of the melt composition is within 80%, 85%, 90%, and / or 95% of the molecular weight (Mw) of the virgin cellulose ester feedstock.

5. The composition according to any one of claims 1 to 4, wherein the plasticizer content of the melt composition is within 87%, within 90%, within 92%, within 94%, within 95%, within 96%, within 98% and / or within 99% of the plasticizer content of the virgin cellulose ester material.

6. The composition according to any one of claims 1 to 5, wherein the glass transition temperature (Tg) of the virgin cellulose ester feedstock is from 100 to 140°C.

7. The composition according to any one of claims 1 to 6, wherein the plasticizer content in the virgin cellulose ester feedstock is from 10 to 30 wt. %8. The composition according to any one of claims 1 to 7, wherein the only source of plasticizer included in the melt composition is from the recycled cellulose ester material and the virgin cellulose ester feedstock.

9. The composition according to any one of claims 1 to 8, wherein the cellulose ester in the virgin cellulose ester feedstock and / or the recycled cellulose ester material is cellulose diacetate and has a degree of substitution of acetyl (DSAC) between 2.2 to 2.8.

10. The composition according to any one of claims 1 to 9, wherein the cellulose ester in the virgin cellulose ester material and / or the recycled cellulose ester material is cellulose diacetate and has a metals-to-sulfur molar ratio (M / S) of from 1.3 to 10.0 and / or a stabilizer metal content of at least 120 ppm.

11. The composition according to any one of claims 1 to 10, wherein the virgin cellulose ester feedstock has a molecular weight in a range from 50,000to 250,000, from 60,000 to 200,000, from 70,000 to 160,000, from 80,000 to 150,000, from 90,000 to 100,000, or from 90,000 to 95,000 Daltons.

12. The composition according to any one of claims 1 to 4, wherein the melt composition comprises a nucleating agent.

13. The composition according to claim 12, wherein the nucleating agent comprises a physical nucleating agent and / or a chemical blowing agent.

14. The composition according to any one of claims 1 to 13, wherein the melt composition comprises a blowing agent chosen from a chemical blowing agent, a physical blowing agent or a combination of a physical blowing agent and a chemical blowing agent.

15. The composition according to claim 14, wherein the blowing agent comprises a combination of a physical blowing agent and a chemical blowing agent.

16. A process for forming a cellulose ester article, wherein the process comprises the following steps:(a) obtaining cellulose ester scrap material;(b) regrinding the cellulose ester scrap material to form a reground scrap material that is particulated;(c) removing moisture from the reground scrap material;(d) obtaining cellulose ester virgin feedstock, wherein the virgin feedstock is a formulated feedstock comprising a cellulose ester and a plasticizer;(e) removing moisture from the virgin feedstock; and(f) combining the reground scrap material and the virgin feedstock to form a cellulose ester melt composition.

17. The process according to claim 16, wherein after said removing moisture of step (c), the reground scrap material has a moisture content of less than 3000 ppm; and wherein after said removing moisture of step (e), the virgin feedstock has a moisture content of less than 1000 ppm.

18. The process according to claim 16 or 17, wherein the scrap material is a foamed material having a density of less than 0.5 g / cc.

19. The process according to any one of claims 16 to 18, wherein said regrinding of step (b) includes densifying the scrap material, wherein the densified reground scrap material has a density of more than 0.4, or more than 0.5 g / cc.

20. The process according to any one of claims 16 to 19, wherein the melt composition comprises at least ten percent (10%) scrap material.

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