Cellulose ester composition containing flow promoter

Abstract

A melt-processable cellulose ester formulation is described that includes an ionic flow promoter to achieve reduced plasticizer content and increased heat dimensional stability. One or more stabilizers can also be included in the formulation. The formulations are particularly suitable for melt processing applications, such as extrusion, and can form useful articles.

Description

Background Technology

[0001] There is a need for a bio-based or biodegradable material whose physical properties are comparable to conventional plastics in a range of applications. Cellulose acetate (CA) is a bio-based and biodegradable resin, and compositions have been used in a variety of melt-processed articles. Cellulose acetate compositions used for melt processing and article formation typically contain a significant amount of plasticizer to allow processing and impart toughness to the molded articles. However, the addition of plasticizer has disadvantages because it reduces the thermal dimensional stability relative to the base cellulose ester. If the plasticized CA composition cannot effectively exclude moisture absorption, then water in the article will act as a plasticizer and further reduce thermal dimensional stability. The low heat distortion temperature (HDT) and high moisture absorption of CA compositions make cellulose ester materials unsuitable for applications that expose molded articles to heat, moisture, and especially a combination of heat and moisture.

[0002] There are many different plasticizers for cellulose acetate. For example, triacetin is a highly effective plasticizer for cellulose acetate, and its bio-based and non-toxic properties make it a good candidate for applications where it will come into contact with food (such as disposable food service items). However, many plasticizers, including triacetin, are quite polar and allow the compounded cellulose acetate to absorb significantly large amounts of moisture, resulting in a lower HDT. Hydrophobic additives can be added to cellulose acetate, resulting in low moisture absorption and a high HDT value even at high humidity levels. Plasticizer levels can also be reduced to increase the stiffness of the article. However, at low plasticizer loadings, melt flowability decreases, leading to pressure build-up during processing or increased melt temperature, thus increasing the risk of thermal degradation. Summary of the Invention

[0003] Adding flow aids to the composition allows for the melt processing of cellulose esters, such as cellulose acetate, at lower plasticizer loadings. In one embodiment, or in combination with any other embodiments mentioned herein, the addition of a fatty acid salt, along with an optional stabilizer, produces a formulation that increases the thermal dimensional stability of the molded article. The fatty acid salt can enhance melt flowability and inhibit water plasticization of the article. A benefit of the fatty acid salt is its significantly lower volatility compared to fatty acids, which can volatilize during melt processing and re-condense on equipment, causing fouling or forming inhalation irritants in the air. The fatty acid salt may be more compatible with cellulose acetate than many fatty acid esters (such as triglycerides, diglycerides, and monoglycerides), which may exude or bloom on the surface.

[0004] In one embodiment or in combination with any other embodiment mentioned herein, a composition is provided comprising: a) a cellulose ester; b) a plasticizer; and c) a flow aid comprising a salt having a melting point of 100°C to 250°C.

[0005] In another embodiment or in combination with any other embodiment mentioned herein, a composition is provided comprising: a) a cellulose ester; b) a plasticizer; and c) a flow aid of greater than 0.3% by weight.

[0006] In another embodiment or in combination with any other embodiment mentioned herein, a composition is provided comprising: a) a cellulose ester; b) a plasticizer; c) a flow aid; and d) a carboxylic acid stabilizer.

[0007] In another embodiment or in combination with any other embodiment mentioned herein, a composition is provided comprising: a) a cellulose ester; b) a plasticizer; and c) a flow aid comprising a blend of metal fatty acid salts.

[0008] In another embodiment or in combination with any other embodiment mentioned herein, a composition is provided comprising: a) a cellulose ester; b) a plasticizer; and c) a flow aid comprising a magnesium salt of fatty acids.

[0009] In another embodiment or in combination with any other embodiment mentioned herein, a composition is provided comprising: a) a cellulose ester; b) a plasticizer; and c) a flow aid. When tested at low pressure in 100% relative humidity (RH) according to ASTM D648, ISO 75, the composition has a heat distortion temperature greater than 50°C. Attached Figure Description

[0010] Figure 1 This is a schematic diagram illustrating the molding process of a bio-based article according to an embodiment of the present invention; and Figure 2 This is a schematic diagram illustrating another bio-based article molding process according to an embodiment of the present invention. Detailed Implementation

[0011] The embodiments generally relate to methods, systems, and compositions for forming bio-based particulate materials (e.g., granules), sheets, and articles. Exemplary processes including methods, systems, and compositions are depicted in Figures 1 to 2 And will be described in more detail below.

[0012] Methods and Systems like Figure 1 and Figure 2 As shown, raw materials can be introduced into a bio-based polymer production process to produce bio-based polymer materials. As used herein, the term "bio-based" refers to a polymer material that is wholly or substantially substantially composed of biological products or renewable agricultural materials. In one embodiment or in combination with any other embodiment mentioned herein, the bio-based polymer material comprises one or more cellulose esters. The one or more cellulose esters may include cellulose acetate. In such embodiments, the raw materials may include 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 be esterified, for example, with acetate to form a bio-based cellulose ester polymer, such as a cellulose acetate polymer.

[0013] Bio-based polymer materials can then be introduced into the compounding process, wherein the bio-based polymer materials can be mixed with plasticizers and flow aids, and optionally one or more other additives (e.g., stabilizers), to form a compound containing the plasticized bio-based polymer. One or more other additives can also be mixed with the polymer, plasticizer, and flow aid. For example, as... Figure 1 As shown, other materials (additives) may include, but are not limited to, stabilizers, one or more physical foaming agents, one or more chemical foaming agents (and / or precursors), one or more nucleating agents, one or more surface-modifying additives, one or more pigments, one or more fillers, and / or one or more other additives. Mixing can be accomplished by any known mixing technique, including but not limited to rolling in a cylindrical container, top stirring, sigma blade mixing, and tumbling.

[0014] The compounding process may include a micronization process. A micronization process typically includes mixing a bio-based polymer material, a plasticizer, a flow aid, and optionally one or more other additives to form a compound composition, and forming microparticles from said composition. In particular, the micronization process may include a granulation process, and the microparticles may include a quantity of granules. The term “compounded CE material” refers to a cellulose ester material formed during the compounding process, which may include a mixture of cellulose esters, plasticizers, flow aids, and optionally other additives. Furthermore, such compounded CE materials may be in the form of microparticles or granules. It should be understood that, as used herein, the phrase “micronization” or “micronization process” may be synonymous with or may at least include “granulation” or “granulation process.” In some embodiments, the micronization process may include granulation in a water bath, granulation on an air-cooled zone, underwater granulation, solvent compounding, etc.

[0015] In one embodiment, or in combination with any other embodiment mentioned herein, a plasticizer, flow aid, and one or more other additives can be mixed with a cellulose ester using conventional melt compounding techniques. These techniques involve combining the cellulose ester with the plasticizer and flow aid, and optionally other additives, at appropriate temperature and pressure in a twin-screw extruder with suitable mixing elements to obtain a molten, homogeneous mixture of cellulose esters as the material exits the extruder. The molten compounded cellulose ester mixture can then be extruded through a die having an orifice with a diameter of about 2-6 mm to extrude a filament. This filament can then be cooled with water (e.g., by underwater granulation) or air and cut at regular intervals to provide uniform and desired size and shape, referred to as “granules” or “particles.” Although methods for forming granules are described herein, it will be understood that, according to some embodiments, the compound fed into the article forming process can be in any physical shape (e.g., granules, powder, particles, fibers). Furthermore, such compounded materials can be in the form of molten mixtures or particulate materials (e.g., granules, powder, particles, fibers, etc.).

[0016] The compounding materials, as mentioned above, can include plasticized bio-based polymer pellets, which can then be introduced into the article molding process, such as... Figure 1 and Figure 2 As shown. In one embodiment or in combination with any other embodiment mentioned herein, the article forming process includes a sheet production process. The sheet production process may include a foam sheet production process. The sheet production process may include one or more zones / steps for producing sheets or films, which will be described in more detail below.

[0017] The molding process can be used to produce foam materials and products or rigid (i.e., non-foam) materials and products. For example... Figure 2 As shown, in one embodiment or in combination with any other embodiments mentioned herein, various additives may be introduced into one or more zones of the article forming process. The article forming process may include an extrusion section, a sheet forming section, and / or a thermoforming section.

[0018] In one embodiment or in combination with any other embodiment mentioned herein, the article forming process may include introducing compounded materials into a heated mixing zone to form a CE melt composition. The heated mixing zone may include, but is not limited to, a mixer (e.g., a static mixer), a roller mill, a kneader, and / or an extrusion process. Other heated mixing processes may also be used. The extrusion process may include one or more extruders, which may include single-screw extruders and / or twin-screw extruders. Within the one or more extruders, the compounded CE composition may be introduced into the extruder barrel and conveyed via one or more screws through a die, which forms an extrudate from the feed composition. As the composition is conveyed through the extruder barrel to the die, the composition may be heated and at least partially melted. Therefore, as used herein, the term "CE melt composition" refers to a cellulose ester-based feed composition that has been melted by the heated mixing zone into a flowable molten resin. Heating may be supplied by an external heater 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, such as molding mandrels and / or thermoforming processes.

[0019] During the article forming process, such as in the heated mixing zone, one or more additives may be introduced into the CE molten resin. For example, a physical foaming agent may be added to the CE molten resin by injecting one or more physical foaming agents into the composition conveyed within the extruder barrel. Other components, such as plasticizers and flow aids, may also be introduced in the heated mixing zone. When the heated mixing zone includes an extruder, the CE molten resin may then be guided through an extrusion die to provide a cellulose ester-based extrudate, which may be further processed to form CE sheets or articles. Although the extrusion process has been generally described above, it should be understood that the article forming process may include one or more other additional or alternative processes for producing articles from the CE molten resin. These processes may include, but are not limited to, profile extrusion, injection molding, thermoforming, injection blow molding, rotational molding, and melt spinning.

[0020] Refer again Figure 1 and Figure 2 The compositions described herein can be used to produce cellulose ester sheets and articles. 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 excellent mechanical properties (e.g., strength, density, cell size, absorption, etc.).

[0021] Composition The methods described above may include the preparation and processing of compositions that can be used for downstream processing to form useful articles. For example, in one embodiment or in combination with any other embodiment mentioned herein, the feed material for the article molding process may include particulate material comprising a bio-based polymer, a plasticizer, a flow aid, and optionally one or more additives, 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 additives (such as those described herein) to provide a mixed composition comprising a bio-based polymer, a plasticizer, a flow aid, and one or more additives. In one embodiment or in combination with any other embodiment mentioned herein, the bio-based polymer comprises a cellulose ester. Further details of the composition components are provided below, including the bio-based polymer (e.g., a cellulose ester), plasticizer, flow aid, optional stabilizer, and other optional additives.

[0022] Although some of the exemplary components described below may be described under more than one category, it should be understood that these components are intended to be included as individual components. For example, although magnesium stearate is described as a flow aid and optional surface-modifying additive or inorganic physical nucleating agent, it may be included alone or added to the composition at different times and / or in different amounts to perform different functions in the composition.

[0023] It should also be understood that compositions according to embodiments of the invention may include or omit certain components described herein, as appropriate for a particular application. Other components not described herein may also be included without departing from the scope of the invention. However, in one embodiment or in combination with any other embodiment, the composition may omit, include less than 1% by weight, or include less than 0.1% by weight of polyester-based additives having polyacids and polyols.

[0024] Cellulose esters The cellulose esters used as described herein can be any known in the art. Cellulose esters that can be used in the embodiments described herein typically comprise repeating units of the following structures:

[0025] Where R 1 R 2 and R 3The substitution level of cellulose esters is independently selected from hydrogen, acetyl, propyl, or butyl. The degree of substitution of cellulose esters is typically expressed as the degree of substitution (DS), which is the average number of non-OH substituents in each adipose glucose unit (AGU). Generally, conventional cellulose contains three substituted hydroxyl groups in each AGU unit; therefore, DS values ​​can range from zero to three. Natural cellulose is a large polysaccharide with a degree of polymerization of 250–5,000 even after pulping and purification, and therefore the assumption of a maximum DS of 3.0 is roughly correct. Since DS is a statistical average, a value of 1 does not guarantee that each AGU has a single substituent. In some cases, unsubstituted adipose glucose units may be present, some may have two substituents and some may have three, and typically, the values ​​will be non-integer. The “total DS” is defined as the average number of all substituents in each adipose glucose unit. The degree of substitution per AGU can also refer to a specific substituent, such as, for example, hydroxyl or acetyl. In one implementation or in combination with any other implementation, n is an integer in the range of 25 to 250, or 25 to 200, or 25 to 150, or 25 to 100, or 25 to 75.

[0026] In one embodiment or in combination with any other embodiment, the cellulose ester has at least two dehydrated glucose rings and may have between at least 50 and up to 5,000 dehydrated glucose rings or between at least 50 and less than 150 dehydrated glucose rings. The number of dehydrated glucose 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, the cellulose ester may have an intrinsic viscosity (IV) of about 0.2 to about 3.0 dL / g, or about 0.5 to about 1.8, or about 1 to about 1.5, as measured at 25°C for a 0.25 g sample in a 60 / 40 weight solution of phenol / tetrachloroethane. In one embodiment or in combination with any other embodiment, the cellulose esters available herein may have a DS / AGU of about 1 to about 3.0, about 2.2 to about 2.8, or 1 to less than 2.2, or 1 to less than 1.5, and the substituted ester is acetyl.

[0027] Cellulose esters can be produced by any method known in the art. Examples of methods for producing cellulose esters are taught in Kirk-Othmer, Encyclopedia of Chemical Technology, 5th Edition, Volume 5, Wiley-Interscience, New York (2004), pp. 394-444. Cellulose is the starting material used for the production of cellulose esters and can be obtained from various grades and sources, such as from cotton linters, softwood pulp, hardwood pulp, corn fiber and other agricultural sources, as well as bacterial cellulose.

[0028] One method for producing cellulose esters involves esterifying cellulose by mixing it with a suitable organic acid, anhydride, and catalyst. The cellulose is then converted into cellulose triesters. Ester hydrolysis is then carried out by adding a water-acid mixture to the cellulose triesters, followed by filtration to remove any gel particles or fibers. Water is then added to the mixture to precipitate the cellulose esters. The cellulose esters can then be washed with water to remove reaction byproducts, followed by dehydration and drying.

[0029] The cellulose triesters to be hydrolyzed may have three acetyl substituents. These cellulose esters can be prepared by many methods known to those skilled in the art. For example, cellulose esters can be prepared by reacting them with a catalyst (such as H2SO4). 4) Cellulose triesters are prepared by heterogeneous acylation of cellulose in a mixture of carboxylic acids and anhydrides in the presence of [agent name missing]. Cellulose triesters can also be prepared by homogeneous acylation of cellulose dissolved in a suitable solvent (such as LiCl / DMAc or LiCl / NMP).

[0030] Those skilled in the art will understand that the commercial term cellulose triester also encompasses cellulose esters that are not fully acyl-substituted. For example, cellulose triacetate, commercially available from Eastman Chemical Company, Kingsport, TN, USA, typically has a DS of about 2.85 to about 2.99.

[0031] After esterification of cellulose to a trimer, some acyl substituents can be removed by hydrolysis or alcoholysis to obtain secondary cellulose esters. As mentioned earlier, the distribution of acyl substituents can be random or non-random, depending on the specific method employed. Secondary cellulose esters can also be prepared directly without hydrolysis using a limited amount of acylating agent. This method is particularly useful when the reaction is carried out in a solvent in which cellulose is dissolved. All these methods yield cellulose esters suitable for use in this invention.

[0032] In one embodiment or in combination with any of the mentioned embodiments, the cellulose acetate is cellulose diacetate having a polystyrene equivalent number-average molecular weight (Mn) of about 10,000 to about 100,000, measured by gel permeation chromatography (GPC) using NMP as a solvent and a polystyrene equivalent 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 weight (Mn) of about 10,000 to about 100,000, measured by gel permeation chromatography (GPC) using NMP as a solvent and a polystyrene equivalent according to ASTM D6474. The values ​​measured by D6474 are 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, The number-average molecular weight (Mn) of polystyrene equivalents is between 0 and 50,000; or between 20,000 and less than 50,000; or between 20,000 and less than 45,000; or between 20,000 and 40,000; or between 20,000 and 35,000; or between 20,000 and 30,000; or between 30,000 and less than 60,000; or between 30,000 and less than 55,000; or between 30,000 and 50,000; or between 30,000 and less than 50,000; or between 30,000 and less than 45,000; or between 30,000 and 40,000; or between 30,000 and 35,000.

[0033] The most common commercial secondary cellulose esters are prepared by initial acid-catalyzed heterogeneous acylation of cellulose to form cellulose triesters. After obtaining a homogeneous solution of the cellulose triester in the corresponding carboxylic acid, the cellulose triester is then subjected to hydrolysis until the desired degree of substitution is obtained. Upon separation, atactic secondary cellulose esters are obtained. That is, the relative degree of substitution (RDS) of each hydroxyl group is approximately equal.

[0034] The cellulose esters that can be used in this invention can be prepared using techniques known in the art and can be selected from various types of cellulose esters, such as cellulose esters available for example from Eastman Chemical Company, Kingsport, TN, USA, for example, 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.

[0035] In one embodiment or in combination with any other embodiment, cellulose esters can be prepared by converting cellulose into cellulose esters using reactants obtained from recycled materials (e.g., a syngas source from recycled plastic contents). In one embodiment or in combination with any other embodiment, such reactants can be cellulose reactants comprising organic acids and / or anhydrides used in the esterification or acylation of cellulose, such as those discussed herein.

[0036] In one embodiment of the invention, or in combination with any of the mentioned embodiments, a cellulose ester composition comprising at least one recycled cellulose ester is provided, wherein the cellulose ester has at least one substituent on a dehydrated glucose unit (AU) derived from recycled contents material (e.g., recycled plastic contents syngas).

[0037] In one embodiment or in combination with any other embodiment, the cellulose ester composition comprises, based on the total weight of the cellulose ester composition, an amount of cellulose ester greater than 25 wt%, greater than 30 wt%, greater than 35 wt%, greater than 40 wt%, greater than 45 wt%, or greater than 50 wt%. The cellulose ester composition may comprise, based on the total weight of the cellulose ester composition, 50 to 99 wt%, or 60 to 99 wt%, or 70 to 99 wt%, or 80 to 99 wt%, or 90 to 99 wt%, or 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%. In some embodiments, the cellulose esters used herein may comprise a combination, blend, or mixture of two or more different types of cellulose esters (i.e., cellulose blended esters). For example, in some embodiments, the cellulose esters used herein may consist of a blend of two or more cellulose esters with different DSACs; however, the blend may have a total DSAC between 2.0 and 3.0, between 2.2 and 2.8, or between 2.3 and 2.7.

[0038] plasticizer In one embodiment or in combination with any other embodiment, the cellulose ester composition described herein may contain at least one plasticizer. The plasticizer reduces melt viscosity and significantly reduces the glass transition temperature (Tg) of the polymer-containing composition (e.g., the cellulose ester composition), for example, when added to an initial polymer-containing composition without additives, forming a modified polymer-containing composition. In one embodiment, "significantly reduces Tg" means that for every one weight percentage increase in additive concentration, the Tg of the composition decreases by at least 0.25°C, 0.5°C, 1°C, 1.5°C, 2°C, 2.5°C, 3°C, 4°C, 5°C, 6°C, 7°C, 8°C, 9°C, or 10°C, determined by the amount of additive between 0.1 and 20 weight percentages. The plasticizer may reduce the heat distortion temperature of the composition in proportion to the amount of additive added to the composition (i.e., in proportion to the additive concentration).

[0039] Plasticizers used for cellulose esters may include triacetin, diacetin, dibutyl terephthalate, dimethyl phthalate, diethyl phthalate, and polyethylene glycol (MW). 200-600, dibutyl tartrate, di-2-methoxyethyl phthalate, ethyl o-benzoylbenzoate, triethylene glycol dipropionate, 1,2-epoxypropylphenyl glycol, 1,2-epoxypropyl(m-tolyl)ethylene glycol, 1,2-epoxypropyl(o-tolyl)ethylene glycol, β-oxyethyl cyclohexenecarboxylate, di(cyclohexyl)diethylene glycol, triethyl citrate, polyethylene glycol, propylene glycol, polysorbate, sucrose octaacetate, acetylated triethyl citrate, acetylated tributyl citrate, Admex, triglycerides, Scandiflex, poloxamer copolymer, polyethylene glycol succinate, diisobutyl adipate, polyvinylpyrrolidone and tribenzoate, plasticizers containing benzoates such as Benz oflex™ plasticizers, poly(alkyl succinates) such as poly(butyl succinate), polyethylene succinate, o-toluenesulfonate, N-ethyltoluenesulfonamide, adipate-based plasticizers, soybean oil epoxides such as the Paraplex™ plasticizers, sucrose-based plasticizers, dibutyl sebate, glyceryl tribanoate, sucrose isobutyrate, Resoflex™ plasticizers, triphenyl phosphate (TPP), triethyl phosphate (TEP), glycolates (e.g., ethyl phthaloyl glycolate "EPEG" and methyl phthaloyl glycolate "MPEG"), methoxy polyethylene glycol, 2,2,4-trimethylpentane-1,3-dimethylbis(2-methylpropionate), and polycaprolactone. In some embodiments, the plasticizers used herein may comprise a combination or mixture of two or more different types of plasticizers.

[0040] In one implementation or in combination with any other implementation, the plasticizer is a food-compliant plasticizer. Food compliance means compliance with applicable food additives and / or food contact regulations, wherein the plasticizer is approved for use or deemed safe by at least one (national or regional) food safety regulatory agency (or organization), such as being listed in the 21 CFR Food Additive Regulations or otherwise listed as Generally Recognized as Safe (GRAS) by the U.S. FDA. In one implementation or in combination with any other implementation, the food-compliant plasticizer is triacetin or polyethylene glycol (PEG) having a molecular weight of about 200 to about 600 or about 300 to 500. Examples of food-compliant plasticizers that may be considered in one implementation or in combination with any other implementation may include triacetin, triethyl citrate, polyethylene glycol, benzoates, propylene glycol, polysorbate, sucrose octaacetate, acetylated triethyl citrate, acetylated tributyl citrate, Admex, triglyceride tripropionate, Scandiflex, poloxamer copolymer, polyethylene succinate, diisobutyl adipate, polyvinylpyrrolidone, and dibenzoic acid diol ester.

[0041] In one embodiment or in combination with any other embodiment, the plasticizer is a bio-based plasticizer and / or a biodegradable plasticizer. Some examples of bio-based plasticizers and / or biodegradable plasticizers include triacetin, triethyl citrate, acetyl triethyl citrate, polyethylene glycol, benzoate-containing plasticizers such as the Benzoflex™ plasticizer series, poly(alkyl succinate) such as poly(butyl succinate), poly(ethylene glycol succinate), adipate-based plasticizers, soybean oil epoxides such as the Paraplex™ plasticizer series, sucrose-based plasticizers, dibutyl sebacate, glyceryl tribanoate, Resoflex™ series plasticizers, triphenyl phosphate, glycolates, polyethylene glycol, 2,2,4-trimethylpentane-1,3-dimethylbis(2-methylpropionate), and polycaprolactone.

[0042] In one embodiment or in combination with any other embodiment, the cellulose ester composition may contain a plasticizer selected from PEG and MPEG (methoxy PEG). The polyethylene glycol or methoxy polyethylene glycol composition has an average molecular weight of 200 Daltons to 600 Daltons, and said composition is melt-processable, biodegradable, and disintegrable.

[0043] In one embodiment or in combination with any other embodiment, the composition comprises polyethylene glycol or methoxy PEG having an average molecular weight of 300 to 550 Daltons.

[0044] In one embodiment or in combination with any other embodiment, the composition comprises polyethylene glycol having an average molecular weight of 300 to 500 Daltons.

[0045] In one embodiment or in combination with any other embodiment, the plasticizer does not contain metal fatty acid salts.

[0046] In one implementation or in combination with any other implementation, the plasticizer does not contain ionic compounds.

[0047] In one embodiment or in combination with any other embodiment, the plasticizer has a melting point temperature of less than 100°C.

[0048] In one embodiment or in combination with any other embodiment, the amount of plasticizer present may be sufficient to allow the cellulose ester composition to be melt-processed (or thermoformed) into useful articles, such as single-use plastic articles, in conventional melt processing equipment.

[0049] In one embodiment or in combination with any other embodiment, the amount of plasticizer present is from 1% to 20% based on 100% by weight of the cellulose ester composition. The amount of plasticizer present may be at least 1% by weight, at least 2% by weight, at least 3% by weight, at least 4% by weight, or at least 5% by weight, at least 6% by weight, at least 7% by weight, or at least 8% by weight and / or not more than 20% by weight, not more than 19% by weight, not more than 18% by weight, not more than 17% by weight, not more than 16% by weight, not more than 15% by weight, not more than 14% by weight, not more than 13% by weight, or not more than 12% by weight.

[0050] Flow aids In one embodiment or in combination with any other embodiment, the cellulose ester composition described herein may contain at least one flow aid. As used herein, the term "flow aid" refers to an additive other than a plasticizer that reduces the melt viscosity of the composition, for example, as measured by the melt flow index (ASTM D1238 / ISO 1133). Advantageously, by including a combination of a flow aid and a plasticizer, the melt viscosity can be reduced to a greater extent compared to the same amount of plasticizer alone. For example, in some embodiments, a cellulose ester composition containing 10% by weight of plasticizer and 2% by weight of flow aid may have a lower melt viscosity than a cellulose ester composition containing 12% by weight of plasticizer and no flow aid. Alternatively or additionally, a cellulose ester composition containing 10% by weight of plasticizer and 2% by weight of flow aid may have the same melt viscosity as a cellulose ester composition containing 20% ​​by weight of plasticizer and no flow aid.

[0051] In one embodiment or in combination with any other embodiment, the flow aid does not significantly reduce the glass transition temperature (Tg) of the polymer-containing composition (e.g., a cellulose ester composition), for example, when added to an initial polymer-containing composition without additives to form a modified polymer-containing composition. In one embodiment, "not significantly reduces Tg" means that for every one weight percentage increase in additive concentration, Tg decreases by no more than C, 0.5°C, 1°C, 1.5°C, 2°C, 2.5°C, 3°C, 4°C, 5°C, 6°C, 7°C, 8°C, 9°C, or 10°C, determined by the additive concentration between 0.1 and 10 weight percentages. In one embodiment, the flow aid does not reduce the heat distortion temperature of the composition proportionally to the amount of additive added to the composition (i.e., proportionally to the additive concentration). In one implementation, "no reduction in HDT" means that for every one-percentage-by-weight increase in additive concentration, the reduction in HDT does not exceed C, 0.5°C, 1°C, 1.5°C, 2°C, 2.5°C, 3°C, 4°C, 5°C, 6°C, 7°C, 8°C, 9°C, or 10°C, as determined by the additive concentration between 0.1 and 10% by weight. Flow aids allow cellulose ester materials (such as cellulose acetate) to be compounded with lower levels of plasticizers, compared to formulations without flow aids.

[0052] In one embodiment or in combination with any other embodiment, the flow aid is a salt. For ease of handling, the flow aid salt may be solid at ambient temperature but will melt during processing (e.g., compounding, extrusion, thermoforming, injection molding). The flow aid may be a salt with a melting point of 100°C to 250°C. Therefore, the flow aid salt may also be referred to as an ionic melt with a melting temperature of 100°C to 250°C. Upon heating, the ionic solid salt melts to form a liquid (or molten) ionic compound.

[0053] Flow aids preferably have relatively low volatility and / or low water solubility. Low volatility inhibits the volatilization of the flow aid during melt processing, while low water solubility helps reduce leaching and minimize the effect of water on the glass transition temperature (Tg) and heat distortion temperature (HDT) of cellulose acetate. Relative volatility can be characterized by thermogravimetric analysis (TGA). For example, in some embodiments, when the flow aid is heated in air at a rate of 20°C to 300°C from 20°C, the flow aid exhibits a weight loss of less than 20%, less than 15%, less than 10%, less than 5%, less than 2%, less than 1%, or substantially no weight loss (i.e., any measured weight loss is attributable solely to the loss of moisture content).

[0054] In one embodiment or in combination with any other embodiment, the flow aid can be an ionic melt composed of both cationic and anionic substances. The cation can be any cation, including organic or inorganic cations. Exemplary organic cations include ammonium, imidazolium, pyridinium, pyrrolidineonium, triazolium, phosphonium, piperidinium, morpholinium, tetrazolium, pyrazolium, sulfonium, or thiazolylium ions. Amino acids can function as cations, particularly arginine, lysine, or histidine. The cation can preferably be inorganic. Exemplary inorganic cations include ions derived from Groups 1 to 12 of the periodic table or from Groups 1 to 2 of the periodic table. The anion can be any anion, including organic or inorganic anions. The anion can preferably be organic. Amino acids can function as organic anions, particularly aspartic acid and glutamic acid. The organic anion may preferably be a carboxylic acid, such as fatty acids with alkyl chains of C8 to C26, or C12 to C18 fatty acids, or mixtures of C12 to C18 fatty acids. The fatty acids may be synthetic or natural, straight-chain or branched, saturated or unsaturated. Exemplary straight-chain, saturated, natural fatty acids include stearic acid, lauric acid, palmitic acid, and myristic acid. Flow aids containing fatty acids may also function as release agents and / or hydrophobic additives in the melt processing of cellulose acetate compositions.

[0055] In one embodiment or in combination with any other embodiment, the flow aid may be an aluminum, calcium, magnesium, potassium, sodium, and / or zinc salt of fatty acids. These may also function as release agents and / or hydrophobic additives in melt-processed cellulose acetate compositions. Aluminum, calcium, magnesium, potassium, and sodium salts may preferably be permitted as food additives under 21 CFR Food Additives or other FDA Generally Recognized As Safe (GRAS) guidelines and will be suitable as additives or flow aids in melt-processed articles intended to contain food. Aluminum, calcium, and magnesium salts are preferably not water-soluble and will prevent leaching from the article. In particular, magnesium fatty acid salts tend to be compatible with plasticized cellulose acetate and form transparent or nearly transparent rigid articles without a waxy surface bloom. Magnesium fatty acid salts may contain one to two molar equivalents of fatty acids. The fatty acids may have alkyl chain lengths of C12 to C18 or mixtures of fatty acids within this range. In one embodiment or in combination with any other embodiment, the flow aid comprises a blend of two or more fatty acid salts. In one embodiment or in combination with any other embodiment, the flow aid comprises magnesium stearate, which is alone or in blend with other metal fatty acid salts.

[0056] In one embodiment or in combination with any other embodiment, the flow aid does not contain esters.

[0057] In one embodiment or in combination with any other embodiment, the flow aid comprises an ionic compound.

[0058] In one embodiment or in combination with any other embodiment, the flow aid has a melting point temperature greater than 100°C.

[0059] In one embodiment or in combination with any other embodiment, the flow aid may be included in the compounded CE composition or melt-processing composition at a rate greater than 0.3 wt%, greater than 0.4 wt%, greater than 0.5 wt%, greater than 0.6 wt%, greater than 0.7 wt%, greater than 0.8 wt%, greater than 0.9 wt%, greater than 1.0 wt%, greater than 1.1 wt%, greater than 1.2 wt%, greater than 1.3 wt%, greater than 1.4 wt%, or greater than 1.5 wt% and / or not exceeding 10 wt%, not exceeding 9 wt%, not exceeding 8 wt%, not exceeding 7 wt%, not exceeding 6 wt%, or not exceeding 5 wt% based on 100 wt% of the total weight of the composition. The flow aid may be included in the composition at a rate from 1 wt% to 10 wt%. Such compositions may further contain plasticizers and stabilizers, as described herein.

[0060] stabilizer It may contain one or more stabilizers that can inhibit or reduce thermal degradation or adverse properties of the polymer composition and article during compounding or other processing of the CE composition. In one embodiment or in combination with any other embodiment, the one or more stabilizers comprise an organic acid (or a blend of organic acids). The organic acid (or blend) has a pKa greater than 3.

[0061] In one embodiment or in combination with any other embodiment, the CE composition comprises one or two carboxylic acid stabilizers. Suitable stabilizers may include organic carboxylic acids capable of neutralizing the alkalinity in the composition, which may develop color during melt processing. For example, organic carboxylic acids may include citric acid, succinic acid, adipic acid, fumaric acid, maleic acid, malic acid, lauric acid, oxalic acid, myristic acid, oleic acid, palmitic acid, and stearic acid, and combinations thereof.

[0062] In one embodiment or in combination with any other embodiment, the one or more stabilizers may be included in the compounded CE composition or melt-processed composition at 0.1% to 10% by weight, 0.5% to 5% by weight, or 1% to 10% by weight, based on 100% by weight of the total composition.

[0063] Biodegradable polymers In one embodiment or in combination with any other embodiment, the cellulose ester composition described herein comprises a biodegradable cellulose ester (BCE) component, said BCE component comprising at least one BCE, which may include one or more of the cellulose esters described herein; and a biodegradable polymer component, said biodegradable polymer component comprising at least one other biodegradable polymer (not a BCE). In one embodiment or in combination with any other embodiment, said other biodegradable polymer may be selected from polyhydroxyalkanoates (PHA and PHB), polylactic acid (PLA), polycaprolactone polymer (PCL), polybutylene terephthalate (PBAT), polyethylene succinate (PES), polyvinyl acetate (PVA), polybutylene succinate (PBS) and copolymers (such as polybutylene succinate-co-butylene 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 (not BCE) in an amount of 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 the biodegradable polymer. In one embodiment or in combination with any other embodiment, the at least one biodegradable polymer comprises having a content of 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. The PHA has a weight-average molecular weight (Mw) ranging from 0 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, wherein the weight-average molecular weight is measured using gel permeation chromatography (GPC) with a refractive index detector and polystyrene standards using methylene chlorosolvent. In one embodiment or in combination with any other embodiment, the PHA may comprise polyhydroxybutyrate-co-hydroxyhexanoate.

[0064] nucleating agent Nucleating agents are chemical or physical materials that provide sites for the formation of cells in molten formulations, such as within CE molten resin. As will be described in more detail below, nucleating agents can be added to the compounded CE material during the compounding process. Optionally or additionally, nucleating agents can be added during the production process of the foam sheet. For example, nucleating agents can be blended with the formulation introduced into the extruder hopper of the extrusion section. Optionally, nucleating agents can be added to the CE molten resin within the extruder itself. Nucleating agents can include physical nucleating agents and chemical nucleating agents. Physical nucleating agents are materials that are immiscible with the polymer matrix of the CE molten resin at the extrusion temperature in 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. Therefore, chemical nucleating agents can be considered (and referred to herein as) precursors to in-situ formed physical nucleating agents.

[0065] Suitable physical nucleating agents will comprise fine particles with desired particle size and / or shape to generate cell nucleation sites within the CE molten resin. For example, in some embodiments, the physical nucleating agent will have an average particle size of less than 1000 micrometers, less than 500 micrometers, less than 100 micrometers, less than 50 micrometers, less than 25 micrometers, less than 20 micrometers, less than 10 micrometers, less than 5 micrometers, less than 2 micrometers, less than 1.5 micrometers, and / or less than 1.0 micrometers. However, in some other embodiments, particles with nanoscale dimensions may be preferred. Furthermore, in some embodiments, the physical nucleating agent will preferably have a high aspect ratio (i.e., width:height). For example, in some embodiments, the average aspect ratio of the physical nucleating agent will be 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, as mentioned above, the physical nucleating agent should be immiscible with the polymer matrix of the CE molten resin at the extrusion temperature of the extrusion section. Therefore, in some embodiments, the physical nucleating agent should have a melt temperature of at least 220°C, at least 230°C, 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. However, the physical nucleating agent can be selected such that it has the ability to recrystallize upon cooling after melting.

[0066] Examples of suitable inorganic physical nucleating agents include, but are not limited to, minerals such as talc, CaCO3, mica, and mixtures of at least two of the foregoing. A representative example is Heritage Plastics HT6000 linear low-density polyethylene (LLDPE) based talc concentrate. Other inorganic physical nucleating agents include wollastonite, silica, silicon dioxide, titanium dioxide, magnesium oxide, aluminum oxide and calcium silicate, barium sulfate, kaolin, aluminum trihydrate ATH (Al(OH)3), MDH (Mg(OH)2), diatomite, magnetite / hematite, halloysite, zinc oxide, and titanium dioxide. In some embodiments, the inorganic nucleating agent will comprise oxides, such as metal oxides or mixed metal oxides, such as oxides 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, silicate, and titanium oxide. In other embodiments, the inorganic nucleating agent will comprise silicates, such as silicates selected from one or more of the following: magnesium silicate and calcium silicate.

[0067] It has been found that bio-based natural particulate materials derived from renewable organic sources (e.g., organic nucleating agents) can also be used as effective physical nucleating agents. Natural materials that can serve as physical nucleating agents include materials composed of cellulose fibers and / or cellulose starch. Examples include, but are not limited to, almond shell powder, animal fibers, apricot shell powder, bamboo powder, bark powder, clam shell powder, coconut shell powder, coir, cork powder, corn cob powder, corn husks, cottonseed hulls, cotton lint and fibers, hazelnut shell powder, kenaf powder, natural fibers, nut shells and powders, oat fiber powder, olive pit powder, peanut shell powder, pecan shell powder, pine nut shell powder, pistachio shell powder, plant fibers, rice husk powder, rice husk grains, rice husks, soybean powder, starch powder (hydrophobic), walnut shell powder, wheat bran, wheat husks, and wood flour. Other organic physical nucleating agents include cellulose powder, chitin, chitosan, metal stearate, carbon black, and dolomite.

[0068] As described above, a suitable chemical nucleating agent (or a precursor to an in-situ formed physical nucleating agent) is configured to decompose upon reaching a threshold chemical reaction temperature to generate cell nucleation sites in the CE molten resin. These small pores act as nucleation sites for the growth of larger pores from physical or other types of blowing agents. In some embodiments, the precursor is configured to form a gas such as CO2 or N2 during the extrusion of the particulate material.

[0069] Examples of chemical nucleating agents include, but are not limited to, acids, such as citric acid or citric acid-based materials. Other acids may include lauric acid, stearic acid, tartaric acid, ascorbic acid, propionic acid, and hexanoic acid. A 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 agent will comprise 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 example, a representative example of a chemical nucleating agent is a combination of citric acid and sodium bicarbonate. In some embodiments, the chemical nucleating agent may include a carrier in which the active component of the nucleating agent is dispersed. For example, another representative example of a chemical nucleating agent is a combination of citric acid, sodium bicarbonate, and a carrier. In some embodiments, the carrier may include polystyrene. However, the carrier may comprise other compositions, such as various biopolymers (e.g., polybutylene succinate, Capa polyester, etc.), polyolefins, acrylic copolymers (e.g., ethylene methyl acrylate), etc. In some such embodiments, citric acid and sodium bicarbonate may constitute about half (wt%) of the chemical nucleating agent, while the support constitutes the remaining half (wt%). Furthermore, in some such embodiments, sodium bicarbonate may constitute more of the chemical nucleating agent than citric acid. For example, in a chemical nucleating agent, sodium bicarbonate may be about three times as much (wt%) as citric acid. It should also be understood that in some embodiments, a support may not be required or used, such as when the nucleating agent is Hecofoam or Hydrocerol.

[0070] In one embodiment or in combination with any embodiment mentioned herein, the nucleating agent is present in amounts of 0.1 to 10 wt%, 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 less than 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 agent used herein may comprise a combination or mixture of two or more different types of nucleating agents.

[0071] Note that cellulose ester materials, whether in the form of compounded CE materials or CE melt resins, generally accept the maximum amount of nucleating agents that can act as nucleation sites. Any remaining nucleating agents added to the cellulose ester material will be retained as fillers. Depending on the type of filler used, fillers can provide various properties to the resulting cellulose ester foams and / or articles. For example, some fillers can provide increased / decreased density, ductility, Young's modulus, yield strength, heat distortion temperature, permeability, impact resistance, elongation at break, adhesion properties, biodegradability, etc., of cellulose ester materials. Fillers can also be used to modify the visual characteristics (e.g., color, opacity, etc.) and tactile characteristics (e.g., material continuity, surface roughness, etc.) of cellulose ester materials.

[0072] foaming agent A foaming agent is a physical or chemical material (or combination of materials) used to expand nucleation sites. Foaming agents can include chemical foaming agents, physical foaming agents, combinations thereof, or several types of chemical and physical foaming agents. The function of a foaming agent is to reduce the density of a material by expanding the cells formed in the molten formulation at nucleation sites. For example, a foaming agent can be added to CE molten resin in an extruder. The hygroscopic properties of bio-based or biodegradable particulate natural fillers allow them to absorb moisture and carry the absorbed water into the molten resin mixture, where water can act as a physical foaming agent.

[0073] Examples of physical blowing agents include H2O, N2, CO2, alkanes, alkenes, esters, ethers, ketones, argon, helium, air, or mixtures thereof. Additionally, it has been surprisingly found that the water-absorbing properties of bio-based or particulate natural fillers allow them to absorb moisture and carry the absorbed water into the molten resin mixture, where water can act as a physical blowing agent. Water-absorbing biodegradable natural fillers can be formulated into compositions that allow the absorption of moisture prior to the foaming process, during which the water is then released to act as a physical blowing agent. Advantageously, water can also be used as a plasticizer for cellulose ester resins. Furthermore, in some embodiments, the physical blowing agent may include hydrocarbons such as pentane / isopentane or butane / isobutane. Other hydrocarbons may include propane, ethane, methane, hexane, cyclohexane, cyclopentane, cyclobutene, etc.

[0074] Chemical blowing agents are materials that degrade or react to produce gases (e.g., CO2 or N2). These gases cause the pores in the molten resin mixture and / or the resulting foam mixture to expand, creating a structural material with multiple gas pores dispersed throughout. Chemical blowing agents can be endothermic or exothermic. They typically degrade at specific temperatures to decompose and release gases. 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 combinations thereof.

[0075] In one embodiment or in combination with any embodiment mentioned herein, the amount of the foaming agent is 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%. 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%. 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 agent used herein may comprise a combination or mixture of two or more different types of blowing agents.

[0076] Surface Modifiers Surface-modifying additives are materials that can be added to cellulose ester compositions to modify the structure of the composition (or the resulting foam article) and thus improve the processing of the cellulose ester composition. For example, adding surface-modifying additives to compounded CE materials (e.g., added to granules during compounding) or CE molten resin (e.g., during extrusion) can improve processing by reducing unwanted adhesion of CE molten resin to the die or mandrel (or other parts of the foam sheet production process). This reduction in adhesion can be achieved by the surface-modifying additive suppressing cellulose ester melting caused by plasticizers. Adding surface-modifying additives can also reduce clogging of cellulose ester foam sheets produced in the sheet forming section. Furthermore, surface-modifying additives can also improve the foam sheet production process by allowing the process to be carried out at lower temperatures.

[0077] Furthermore, in some embodiments, the surface-modifying additive can function as an antistatic additive, which suppresses electric sparks or arcs in the molten CE resin. Suppressing electric sparks or arcs may be particularly important when hydrocarbons are used as blowing agents to reduce the chance of igniting the hydrocarbons and causing a fire. Advantageously, the surface-modifying additive can also reduce the diffusion of blowing agents such as hydrocarbons from the foam sheet or the resulting article. In some embodiments, the hydrocarbon itself can be used as a surface-modifying additive.

[0078] However, more general examples of surface-modifying additives according to embodiments of the present invention that can be used in the formulation of CE materials (e.g., during the formulation process) or CE melt resins (e.g., during the production of foam sheets) include fatty acids such as palmitic acid, animal fatty acid, stearic acid, oleic acid, linoleic acid and linolenic acid, arachidic acid / behenic acid, behenic acid and erucic acid. Surface-modifying additives may also include fatty acid amides such as erucamide, oleamide, stearamide, behenic acid amide, glycolamide, secondary amide and diamide.

[0079] Further examples of surface-modifying additives may include glycerides and / or stearates, such as monoglycerides, diglycerides, and triglycerides. Monoglycerides may include glyceryl monostearate or monoglyceride derivatives, such as diacetyl tartrate (DATEM) of monoglycerides and diglycerides, ethoxylated monoglycerides, succinyl glycerides, and propylene glycol monoester (PGME). Examples of surface-modifying additives may also include metal stearates, such as aluminum stearate, calcium stearate, lithium stearate, magnesium stearate, sodium stearate, zinc stearate, and / or combinations thereof (e.g., calcium stearate / zinc stearate). Examples of surface-modifying additives may also include waxes, such as polyolefin waxes (polypropylene waxes and polyethylene waxes), oxidized olefin waxes, ethylene acrylate (EAA) copolymer waxes, ethylene methyl acrylate (EMA) copolymer waxes, EAA ionomer waxes, acrylic waxes, and / or natural waxes, such as rice bran wax, sunflower wax, sugarcane wax, candelilla wax, soybean wax, beeswax, candelilla wax, and carnauba wax.

[0080] Other non-exclusive examples of surface-modifying additives include aliphatic diesters (e.g., dioctyl adipate), polyethylene glycol diesters, alkyl alkyl ether diesters, aromatic triesters, polyester resins, chlorinated hydrocarbons, halogenated hydrocarbons, alkyl ether monoesters, and alkyl monoesters. Additionally, various oils can be used as surface-modifying additives, such as aromatic oils, naphthenic oils, glycerol ester oils, silicone oils, and epoxidized oils (e.g., soybean oil and linseed oil). Therefore, in some embodiments, the surface-modifying additive includes plasticizers, such as aliphatic diester plasticizers, polyester plasticizers, etc. Furthermore, in some embodiments, the surface-modifying additive may include polyhedral oligomeric silsesquioxanes (POSS).

[0081] More generally, the surface-modifying additives used in embodiments of the present invention can have a lower polarity than the cellulose esters in the compounded CE materials (e.g., during compounding) or CE melt resins (e.g., during foam sheet production). For example, the surface-modifying additives can have (based on the Hansen solubility parameter): less than 25 MPa 1 / 2 Less than 20 MPa 1 / 2 or less than 19.5 MPa 1 / 2 Total solubility parameter δ; less than 18 MPa 1 / 2 Less than 16 MPa 1 / 2 or less than 14 MPa 1 / 2 Dispersion force solubility parameter δ d Less than 12 MPa 1 / 2 Less than 8 MPa 1 / 2 or less than 4 MPa 1 / 2 The solubility parameter δ of dipole intermolecular forces d; and / or less than 11 MPa 1 / 2 Less than 10 MPa 1 / 2 or less than 9 MPa 1 / 2 hydrogen bond solubility parameter δ h However, in some other embodiments, the surface-modifying additives used in these embodiments may have a higher polarity than the cellulose esters in the compounded CE materials (e.g., during compounding) or CE melt resins (e.g., in the foam sheet production process). For example, the surface-modifying additive may have (based on the Hansen solubility parameter): greater than 21.5 MPa. 1 / 2 Greater than 23 MPa 1 / 2 or greater than 25 MPa 1 / 2 The total solubility parameter δ is also considered. Additionally, in some embodiments, the surface-modifying additive 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 additive 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 not exceeding 1000 g / mol, not exceeding 2500 g / mol, or not exceeding 5000 g / mol. Moreover, it may be preferred that the surface-modifying additive is insoluble in one or more plasticizers used in the cellulose ester composition. For example, it may be preferred that the surface-modifying additive is insoluble in triacetin. Finally, in some embodiments, the surface-modifying additive may be biodegradable and / or food compliant or FDA approved.

[0082] In one embodiment or in combination with any embodiment mentioned herein, the surface-modifying additive is present in an amount of 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%, or 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 additive used herein may comprise a combination or mixture of two or more different types of surface-modifying additives.

[0083] Products In one embodiment or in combination with any of the embodiments mentioned herein, the cellulose ester composition can be formed into sheets and / or articles during the article molding process described above. The sheets and / or articles can be foamed or rigid. In some embodiments, the molded sheets can be further processed (e.g., thermoforming) into useful articles. In some embodiments, the articles can be biodegradable and / or compostable, and / or the articles can have excellent mechanical properties (e.g., strength, density, cell size, absorption, etc.).

[0084] Exemplary articles comprising cellulose ester compositions are provided for use in food service and grocery, horticulture, agriculture, recreation, coatings, fibers, nonwovens, and home / office applications. Examples of food service and grocery products include, but are not limited to, straws, cup lids, composite lids, dispensing cups, beverage cups, trays, bowls, plates, food containers, container lids, flip-top containers, cutlery, utensils, stirrers, jars, can lids, bottles, bottle caps, bags, flexible packaging, wrapping materials, produce baskets, produce stickers, and hemp rope. Examples of horticulture and / or agriculture applications include, but are not limited to, plant pots, germination trays, transplanting pots, plant labels, buckets, bags for soil and mulch, trimming rope, agricultural films, mulch films, greenhouse films, silage films, composting bags, film stakes, and hay bale rope. Examples of recreational products include, but are not limited to, toys, sporting goods, fishing gear, golf equipment, and camping equipment. Toys may include, but are not limited to, beach toys, building blocks, wheels, propellers, straw cups, doll accessories, and pet toys. Sports equipment may include, but is not limited to, whistles, waffle balls, rackets, nets, foam balls, darts, and artificial turf. Fishing gear may include, but is not limited to, floats, bait, nets, and fish traps. Golf equipment may include, but is not limited to, tees, practice balls, tee markers, and grass-cutting tools. Camping equipment may include, but is not limited to, tent pegs, dining utensils, and ropes / ropes. Examples of household and office products may include, but are not limited to, gift cards, credit cards, logos, labels, report covers, mailing packaging, tape, tool handles, toothbrush handles, writing instruments, combs, film rolls, wire insulation, nuts, and bottles.

[0085] In one embodiment or in combination with any of the embodiments mentioned herein, the article is made of a moldable thermoplastic material comprising a cellulose ester composition as described herein.

[0086] In one embodiment or in combination with any of the embodiments mentioned herein, the article is a single-use food contact article. Examples of such articles that can be made from cellulose ester compositions include cups, trays, multi-compartment trays, flip-top packaging, candy bars, films, sheets, trays and lids (e.g., thermoformed), straws, plates, bowls, dispensing cups, food packaging, liquid-carrying containers, egg cartons, solid or gel-carrying containers, and tableware. In an embodiment, the cellulose ester may be a coating or layer of the article. The article may contain fibers. In an embodiment, the article may be a horticultural article. Examples of such articles that can be made from cellulose ester compositions include plant pots, plant labels, mulch films, and agricultural ground cover.

[0087] Articles formed using compositions according to embodiments of the invention can advantageously exhibit desired thermal stability properties. For example, the thermal stability of the articles can be characterized by the heat distortion temperature of the composition tested according to ASTM D648, ISO 75. In one embodiment or in combination with any of the embodiments mentioned herein, the CE composition has a heat distortion temperature greater than 50°C, greater than 55°C, or greater than 60°C when tested at low pressure and 100% relative humidity (RH) according to ASTM D648, ISO 75.

[0088] Further inventive concepts related to compositions, processes, and systems for producing granules, sheets, and / or articles.

[0089] In one embodiment or in combination with any embodiment mentioned herein, the sheet or article is industrially compostable or household compostable. In one subclass of this category, the sheet or article is industrially compostable. In one sub-subclass of this category, the sheet or article has a thickness of less than 6 mm. In one sub-subclass of this category, the sheet or article has a thickness of less than 3 mm. In one sub-subclass of this category, the article has a thickness of less than 1.1 mm. In one subclass of this category, the sheet or article is household compostable. In one sub-subclass of this category, the sheet or article has a thickness of less than 6 mm. In one sub-subclass of this category, the sheet or article has a thickness of less than 3 mm. In one sub-subclass of this category, the sheet or article has a thickness of less than 1.1 mm. In one sub-subclass of this category, the sheet or article has a thickness of less than 0.8 mm. In one sub-subclass of this category, the sheet or article has a thickness of less than 0.6 mm. In a sub-subclass of this subclass, the sheet or article has a thickness of less than 0.4 mm.

[0090] In one embodiment or in combination with any of the embodiments mentioned herein, the thickness of the sheet or article is 1 to 10 mm, 1 to 8 mm, 2 to 8 mm, 3 to 7 mm, 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 sheet or article may have other larger dimensions. For example, in some embodiments, the sheet or article may have a thickness of 0.5 to 24 inches, 1 to 15 inches, or 3 to 12 inches.

[0091] Compositions used to prepare biodegradable cellulose acetate sheets and articles may contain other additives, such as fillers, odor modifiers, waxes, compatibilizers, biodegradation promoters, dyes, pigments, colorants, lubricants, antioxidants, viscosity modifiers, antifungal agents, antibacterial agents, softeners, release agents, UV absorbers, and combinations thereof. The amount of each additional additive in the cellulose ester-based material may be 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.%.

[0092] As noted above, it should be understood that compounds or materials of the same type can be identified or included in multiple component classes for cellulose ester compositions. For example, polyethylene glycol (PEG) can function as a plasticizer or as an additive that does not function as a plasticizer, such as a hydrophilic polymer or a biodegradation promoter. For example, lower molecular weight PEG has a plasticizing effect, while higher molecular weight PEG functions as a hydrophilic polymer but does not have a plasticizing effect.

[0093] In one embodiment or in combination with any other embodiment mentioned herein, the composition further comprises a photodegradation catalyst. In one category of this embodiment, the photodegradation catalyst is titanium dioxide or iron oxide. In a subcategory of this category, the photodegradation catalyst is titanium dioxide. In a subcategory of this category, the photodegradation catalyst is iron oxide.

[0094] In one embodiment or in combination with any other embodiment mentioned herein, the composition further comprises a pigment. In one category of this embodiment, the pigment is titanium dioxide, carbon black, or iron oxide. In a subclass of this category, the pigment is titanium dioxide. In a subclass of this category, the pigment is carbon black. In a subclass of this category, the pigment is iron oxide. In a subclass of this category, the pigment is a biodegradable particulate natural filler.

[0095] definition It should be understood that the following is not intended to be an exhaustive list of the defined terms. Other definitions may be provided in the foregoing description, such as when used in the context of the defined terms.

[0096] As used herein, the terms “a / an” and “the” mean one or more species.

[0097] As used herein, the terms “comprising, comprises, and comprise” are open-ended transition words used to transition from an object described before the term to one or more elements described after the term, wherein the one or more elements listed after the transition word are not necessarily the only elements constituting the subject.

[0098] As used herein, the term "flow aid" refers to an additive other than a plasticizer that reduces the melt viscosity of a composition, for example, as measured by the melt flow index (ASTM D1238 / ISO 1133).

[0099] As used herein, the term "bio-based" refers to materials that are wholly or substantially substantially composed of biological products or renewable agricultural materials (e.g., one or more polymers).

[0100] To be considered “compostable,” a material must meet the following four criteria: (1) the material must pass the biodegradation requirement in a test at elevated temperature (58°C) under controlled composting conditions according to ISO 14855-1 (2012), corresponding to 90% absolute biodegradation or 90% relative biodegradation compared to a control polymer; (2) the material must achieve 90% disintegration under aerobic composting conditions according to ISO 16929 (2013); (3) the tested material must meet all requirements for volatile solids, heavy metals, and fluorine as specified in ASTM D6400 (2012), EN 13432 (2000), and ISO 17088 (2012); and (4) the material should not have a negative impact on plant growth.

[0101] As used herein, the term "biodegradable" generally refers to the biotransformation and consumption of organic molecules. Biodegradability is an inherent property of a material, and materials can exhibit varying degrees of biodegradability depending on the specific conditions under which they are exposed. The term "disintegrable" refers to the tendency of a material to physically break down into smaller fragments when exposed to specific conditions. Disintegration depends on the material itself and the physical size and configuration of the article being tested. Ecotoxicity measures the effects of materials on plant life and determines the heavy metal content of the material according to procedures specified in standard test methods.

[0102] According to French standard NF T 51-800 and Australian standard AS 5810, for a material to be considered "biodegradable" under home composting conditions, it must exhibit at least 90% total biodegradation (e.g., compared to the initial sample), or at least 90% of the maximum biodegradation of a suitable reference material after both the reference and test articles have reached a stabilization period. The maximum testing period for biodegradation under home composting conditions is one year.

[0103] According to ASTM D6400 and ISO 17088, to be considered "biodegradable" under industrial composting conditions, at least 90% of the organic carbon in the entire article (or for each component present in amounts exceeding 1% by dry mass) must be converted to carbon dioxide by the end of the test period, compared to a control or absolute value. According to European Standard ED 13432 (2000), the material must exhibit at least 90% total biodegradation, or at least 90% of the maximum biodegradation of a suitable reference material after both the reference and test articles have reached a stabilization period. The maximum test duration for biodegradability under industrial composting conditions is 180 days.

[0104] According to Vinçotte's OK biodegradable soil conformity mark and DIN CERTCO's DIN Geprüft soil biodegradability certification scheme, to be considered "biodegradable" under soil composting conditions, a material must exhibit a total biodegradation of at least 90% (e.g., compared to the initial sample), or at least 90% of the maximum biodegradation of a suitable reference material after both the reference and test articles have reached a stabilization period. The maximum testing duration for biodegradability under soil composting conditions is 2 years.

[0105] In one embodiment or in combination with any other embodiment, when the article has a density of 0.643 g / cm³ 3 The article comprises 25.4 mm × 25.4 mm × 1 mm foam and exhibits at least 50%, or at least 55%, or at least 60%, or at least 65%, or at least 70%, or at least 75%, or at least 80%, or at least 85% disintegration under industrial or domestic composting test conditions according to ISO 20200 standards. In one category of this embodiment, the article exhibits 50% to 90%, or 55% to 90%, or 60% to 90%, or 65% to 90% disintegration under industrial or domestic composting test conditions according to ISO 20200 standards.

[0106] Example Example 1. Synthesis of non-volatile fatty acid metal salts from fatty acids and metal oxides or hydroxides.

[0107] Magnesium salts of synthetic fatty acids were used as non-volatile hydrophobic additives. A series of mono- and di-fatty acid magnesium salts were prepared from lauric acid (C12), palmitic acid (C16), or stearic acid (C18), respectively. A catalytic amount of acid was then added to initiate a neutralization reaction. Magnesium hydroxide was dispersed in water (1 mol Mg(OH)₂ / L water) and heated to above the melting point of the fatty acids (typically 85 °C). Citric acid (0.05 equivalents) was added as an initiator along with the fatty acids (1 or 2 equivalents) to the magnesium hydroxide slurry, and the mixture was stirred to melt and mix the reactants. The mixture was reacted overnight at 85 °C. The fatty acid salts were insoluble in water and precipitated as they formed. The fatty acid salts were separated from the reaction by filtration and washed with deionized water until the TDS (total dissolved solids, as measured by a conductivity meter) of the filtrate was <20 ppm. The separation yield was >93% based on the starting materials. The product is insoluble in triacetin (TA) or PEG400, and the reaction itself cannot be carried out in TA or PEG400 as solvents.

[0108] Thermogravimetric analysis (TGA) was used to compare relative thermal stability and volatility. All fatty acid salts were solids and pre-dried at 50°C to remove excess moisture. The volatility of lauric acid alone was clearly visible from the TGA. Weight loss began at approximately 150°C, with the starting point marked as 209 on the TGA curve, and reached its peak or maximum rate at approximately 245°C. In contrast, the magnesium fatty acid salts maintained this level up to over 300°C. Most of these formulations showed signs of dehydration, with weight losses of approximately 3% to 6% at temperatures between 80°C and 110°C. However, the salts themselves are not volatile.

[0109] Table 1. Thermal stability of TGA.

[0110]

[0111] Sodium and calcium salts are also made from palmitic acid and stearic acid. Sodium hydroxide and calcium hydroxide can form insoluble salts from fatty acids in water without the need for an acid initiator.

[0112] Example 2. Compression-molded film obtained from dry blends Dry blends for compression molding were prepared according to Table 2. The plasticizer, along with any additives, was added to the cellulose diacetate (CA398-30) powder, and the blends were then mixed in a coffee grinder. Each complete dry blend was pre-weighed (5.0 g) into an aluminum pan and dried at 60°C for 2 h.

[0113] Press the film for a total of 4 minutes on a heated press, with the upper and lower plates preheated to 425℉ (218°C). Apply the pre-dried CA / TA / additive dry blend to the center of a 4 sq. inch, 10 mil thick frame located between the top and bottom aluminum foil layers (entirely between two steel plates). Place the assembly in the press and heat at 0 pressure for 1 minute to dry and pre-melt the powder, then press at 12,000 PHI for 1 minute, increasing to higher pressure over approximately 30 seconds, and finally holding at 20,000 PHI for 2 minutes (pump force, in pounds).

[0114] With low plasticizer content (10% triacetin; TA), melt flowability at 218°C is poor—insufficient to fully fill the frame during compression molding. Adding 2% to 5% magnesium fatty acid salts results in good flowability sufficient to fill the frame and produce a clear or nearly clear film. In contrast, containing 2% sodium (Na) fatty acid salts results in a very dark color during compression molding, or otherwise, white or inclusion-prone areas are noticeable in compressed films containing 2% calcium stearate or zinc stearate salts.

[0115] Table 2. Compression molded films made with CA398-30.

[0116]

[0117] Example 3. Compounding (with stabilizer) on a twin-screw extruder Formulations were prepared in 1-pound batches, each containing 86% CA394-60S (ground); 10% triacetin; 2% fatty acid salts (according to Table 3); and 1% citric acid and 1% palmitic acid as stabilizers. The materials were compounded on a Eurolab Prism extruder with a universal screw design. The screw diameter was 16 mm, L / D = 40:1, and the screw length was 640 mm. The barrel temperature was set to 220°C. Analysis of the pellets included triacetin content and melt flow index (MFI).

[0118] Table 3. Composition of formulations compounded on the TSE

[0119] Comparative Example 3a. Mixing without stabilizers

[0120] Formulate the compounded product according to Table 3a on a laboratory-scale twin-screw extruder. Pre-ground CA394-60S. The pellets are dark brown and cannot be pressed into films or injection molded into flexural bars.

[0121] Table 3a. Composition and loading of compounded products.

[0122]

[0123] Example 4. Transparency of the pressed film The film was pressed from the compounded granules of Example 3. The film was pressed for a total of 4 minutes on a heated press (PHI), with the upper and lower plates preheated to 425℉ (218°C). The granules were applied to the center of a 4 square inch, 10 mil thick frame located between the top and bottom aluminum foil layers (entirely between two steel plates). The assembly was placed in the press and heated at 0 pressure for 1 minute to dry and pre-melt the puck, then pressed at 12,000 PHI for 1 minute, increasing to higher pressures over approximately 30 seconds, and finally held at 20,000 PHI for 1.5 minutes (pump force, in pounds). Haze and clarity were measured using a Haze-gard instrument (BYK). Transparency was quantified as color difference ΔE (CIE76). Transparency was considered a compatibility indicator (Table 4).

[0124] Table 4. Effect of flow aids on membrane clarity.

[0125]

[0126] Example 5. Formulating with stabilizers in a twin-roll mill or twin-screw extruder. The compositions in Table 5A were pre-blended at a scale of 200 g. CA394-60S was pre-ground. The blends were compounded on a laboratory-scale two-roll mill (TRM) with a residence time of up to 10 minutes. Rear roll temperature: 205°C; Front roll temperature: 215°C; Roll gap: 20 micrometers.

[0127] The formulations in Table 5B were compounded on a twin-screw extruder (TSE) using a high-mixing screw with a diameter of 40 mm to form granules. The melt temperature was set to 225°C. The material was pre-ground to CA394-60S.

[0128] Table 5A. Compositions prepared on a two-roll mill.

[0129]

[0130] Table 5B. Compositions formulated on the TSE.

[0131]

[0132] Example 6. HDT at 100% RH for comparing heating dimensional stability. The compounded granules from Example 5 were injection molded into flexural bars according to ASTM D648 to determine the heat deflection temperature (HDT). The low pressure (LPRS) HDT of the flexural bars was measured after equilibration at 20°C and 50% RH, and separately after equilibration at 20°C and 100% RH for 48 h.

[0133] Table 6. HDT (temperature in degrees Celsius) of the compounds

[0134] Example 7. Batch foaming

[0135] The two formulations (Table 7) were compounded on a twin-screw extruder using a 40 mm diameter high-mixing screw to form granules. The melt temperature was set to 225°C. CA394-60S was then ground.

[0136] Table 7.

[0137] Press the membrane on a Carver heated press. Press the membrane for a total of 7 minutes, with the upper and lower plates preheated to 428℉ (220°C). Apply the blend to the center of a 4 sq. inch, 10 mil thick frame located between the top and bottom Kapton membranes (entirely between two Teflon blocks). Place the assembly in the press and heat at 0 pressure for 5 minutes to dry and pre-melt the material, then press at 10,000 PSI for 1 minute, increasing to higher pressure over approximately 60 seconds, and finally holding at 40,000 PSI for 1 minute.

[0138] The pressed membranes are subjected to batch foaming. Batch foaming is performed in a 300 mL high-pressure autoclave (Parr Instrument Company model 4561) with a diameter of 2.5 inches and a depth of 4 inches, equipped with thermocouples. The suction tube, stirring shaft, and impeller are removed from the autoclave. In a typical experiment, three to four 10 mil thick membranes (1 inch × 1 inch) are placed on custom trays (L × W × H, 1.5 × 1.5 × 0.5 inches). Each tray holds one membrane, and the trays are stacked on top of each other inside the autoclave. The trays are made by folding Teflon-lined foil to the desired size. The vessel is closed, tightly sealed, and then heated to the desired temperature, which can range from 150°C to 230°C. Once the desired temperature is reached, CO2 gas is pumped into the vessel through a supply valve to achieve the desired pressure (50–130 bar). Once the vessel has reached equilibrium at the set temperature, allow it to stabilize for 30 minutes, providing ample time for CO2 gas to permeate into the membrane. At the end of the residence time, rapidly release the pressure to atmospheric pressure through a fully open valve on the 0.25” vent pipe while purging with air. Allow the vessel to cool to room temperature and remove the foam membrane. Place the foam membrane sample in a Ziploc bag and store it in a refrigerator until further testing.

[0139] Example 8. Characterization of batch foam samples The foam samples from Example 7 were analyzed. The foam density was measured using an XSR analytical balance equipped with a Mettler-Toledo density kit (model #30460852) for batch foam sample density measurement. A weighing basket was placed on the density attachment, and a beaker was placed on the base. The provided beaker was filled with deionized water to completely cover the weighing basket. A provided thermometer was placed on the side of the beaker. The water was allowed to acclimate to room temperature (approximately 10 minutes) before use. The kit is capable of measuring the density of solid, liquid, porous, and floating samples. Foam was cut from the sheet using a 22 mm circular punch. The foam block was first weighed in air (on the pan at the top of the kit) and then immersed in water (held in place by the basket). The balance used this information to calculate the density. Each sample was analyzed five times in replicates, and the average density was calculated.

[0140] The foam cells are uniform and evenly distributed. The average pore size was measured using SEM (Scanning Electron Microscopy) images. The pore size distribution was calculated by first manually tracing the pore outlines on the SEM image of the foam sample using a computer mouse. Typically, 10 representative pores were selected for tracing in the image. Once the manual tracing step was complete, the remaining portion was processed using an image processing algorithm that processed the traces. The algorithm determined the maximum diameter of the trace in pixels. The pixel diameter was then converted to a real-world diameter in micrometers using a scale bar in the image. The diameter of each image was then averaged and reported in Table 8.

[0141] Table 8.

[0142] Example 9. Sheet extrusion (1.5-inch Killion), 10 wt% and 12 wt% TA Materials #33 and #37 were melt-extruded into 20-mil thick sheets. A 1.5-inch diameter extruder was used with a 12-inch wide die for feeding. Films extruded from formulation #33 containing 10% triacetate did not process well; the films were blurry and very brittle. However, films extruded from formulation containing 12% triacetate processed much better and were more transparent.

[0143] Table 9.

[0144] Example 10. Compounding and Foam Extrusion The formulation was compounded on a twin-screw extruder (TSE) using a 40 mm diameter high-mixing screw to form granules. The melt temperature was set to 225°C. CA394-60S was pre-ground. The composition of the compounded granules is as follows: 86 wt% Eastman CA-398-30 or CA-394-60S 12 wt% Triacetin (Plasticizer) 2 wt% magnesium stearate (flow aid) 1 wt% Citric Acid (Stabilizing Additive) 1 wt% Palmitic acid (stabilizing additive) CA resin powder and solid white powder additives were blended in a bag and fed through the main feeder, while liquid plasticizer was fed into zone 2 of the extruder barrel using a liquid injector. The compounded feedstock was then passed through a water tank and granulated using a ConAir granulator. Representative twin-screw extrusion conditions are detailed in Table 10A below. The extruded granules were then used for foam sheet extrusion, as well as subsequent analysis and prototype thermoforming.

[0145] Table 10A. Conditions for compounding twin-screw extruders.

[0146]

[0147] The resulting granules were then pre-dried overnight at 60°C before being extruded as foam sheets. Foam extrusion was performed on a 1.5-inch Killion sheet extruder equipped with a Maddock mixing screw and an adjustable sheet / film die. The dried compounded granules were bag-blended with a chemical foaming agent (Foamazol 73S, sold by Bergen International) (also in granule form) at a concentration of 1 wt%, and then fed into the extruder through the main feeder. Representative foam sheet extrusion conditions are detailed in Table 10B below. Foam sheets were extruded to a thickness of 40 mils (approximately 1 mm), and their bulk density was measured to be 0.643 g / cm³ using the procedure described in Example 8. 3 This material was thus classified as a "medium-density" foam sheet. Scanning electron microscopy (SEM) was used to characterize the cell morphology of the foam sheet, as described in Example 8. The average pore size was measured to be 227 micrometers. Overall, the cells appeared to vary in size and have an irregular shape in the transverse direction. Several foam cells also appeared to merge with adjacent cells to form larger cells.

[0148] Table 10B. Extrusion conditions for foam sheets.

[0149]

[0150]

[0151] Example 11. Cobb test analysis to measure water and oil absorption of foam sheets. The amount of water and oil absorbed by the extruded foam sheet sample in Example 10 was characterized by a Cobb test, i.e., water absorption rate and oil absorption rate. This test was performed in accordance with ISO 535:2014 (E) "Paper and board - Determination of water absorptiveness - Cobb method". A circular sample with a diameter of 6 cm was cut from the foam sheet and its weight was recorded (previous weight). It was then mounted in the testing equipment and secured to form a leak-proof seal. Room temperature tap water was filled into the test cup and the sample was kept for 30 minutes. The sample was then carefully removed from the cup, excess water was aspirated, and the sample was reweighed (postvous weight). The difference between the previous and postvous weights was normalized using the sample surface area to obtain the result in g / cm³. -2The water absorption rate is expressed in units of [unit missing]. Oil absorption rate was obtained by replacing water with oil and following the same procedure. The water absorption rate and oil absorption rate of the extruded foam sheet of Example 10 of the composition described in this invention were measured to be 14 g / cm³. -2 and 24 g cm -2 .

[0152] Example 12. Modulus measurement of foam sheets under high temperature and high humidity conditions Dynamic mechanical analysis (DMA) was performed under high temperature and relative humidity (RH) conditions to determine the degree of stiffness or modulus loss in the extruded foam sheet of Example 10. The instrument used was a TA Instruments DMA Q850 equipped with a film tension clamp and RH control unit. Test specimens with a thickness of 1.12 mm were cut into fixed widths of 6.35 mm. The effective length of the specimen was measured to be 10.74 mm after loading. Initially, to avoid applying stress / strain to the specimen under a controlled force of 0 N, the temperature and RH were equilibrated at 80°C and 0% for 240 minutes, respectively. After equilibration, vibration measurements were performed at a strain level of 0.1% and a frequency of 1 Hz. The same procedure was performed at 60% RH. Modulus data for the RH levels of the two tests were recorded and compared. When RH increased from 0 to 60%, the foam sample of the composition of the present invention extruded in Example 10 exhibited a 27% modulus loss.

[0153] Example 13. Melt flow rheology and MFI evaluation of compounds with and without flow aids.

[0154] The small amplitude oscillating shear (SAOS) melt flow rheological properties of the compositions described in this invention were measured and compared with compounds prepared without any flow aids or additives and with different concentrations of triacetyl plasticizer. Tests were performed on a TAInstruments ARES-G2 rotational rheometer using a 25 mm stainless steel parallel plate geometry. The samples used for testing were in granular form. Frequency scans from 1 to 100 rad / s were performed between 200°C and 230°C in 5°C increments using a constant strain setting of 0.1%. The sample melt was allowed to be homogenized and equilibrated for 90 seconds at each temperature. The frequency scan data obtained at different temperatures were shifted to a reference temperature according to the time-temperature superposition (TTS) principle. T ref ) 230℃, and construct complex viscosity ( η* Pa-s) and angular frequency ( ω The principal curve (rad / s) was then used. Subsequently, the Cox-Merz principle was applied to the angular frequency axis of the principal curve (...). ω ) converted to shear rate ( (1 / s). Therefore, η* and The master curve is fitted to the Cross model equation to obtain zero shear viscosity. η 0 (Pa-s), the zero-shear viscosity of all compounds in this example is listed in Table 13.

[0155] The melt flowability of the compositions described in this invention was also characterized using a melt flow index (MFI) test and compared with compounds prepared without any flow aids and with different concentrations of plasticizer. MFI tests were performed according to ASTM D1238 at 240°C using loads of 2.16 kg and 5 kg. Table 13 also lists the MFI values ​​for all compounds in this example, in g / 10 min. As demonstrated from Table 13, with decreasing plasticizer concentration... η 0 Increases and decreases MFI. However, adding flow aids to low-plasticizer compounds leads to... η 0 The decrease and increase in MFI demonstrate the effectiveness of flow aid additives in increasing the melt flowability of cellulose ester compounds.

[0156] Table 13. Melt flow characteristics of compounds with and without flow aids.

[0157]

[0158] Example 14. Industrial and domestic compostability tests of foam sheet samples prepared with and without flow aid additives.

[0159] The disintegration percentage (%) of the extruded foam sheet from Example 10 was characterized in industrial (IC) and domestic composting (HC) environments according to the ISO 20200 method. Synthetic compost mixtures for both tests were prepared within the framework specified in the standard test methods. The compost mixtures were divided into two reactor chambers, and the test samples were placed within them. The foam samples used were 1” × 1” square specimens, comprising approximately 0.5 wt% of 1000 g of synthetic compost mixture. The industrial composting test ran for a total of 12 weeks, while the domestic composting test ran for 26 weeks. The mixing and moisture % adjustment schemes for the IC and HC compost mixtures were performed according to the ISO 20200 method. At the end of both the IC and HC tests, the compost was sieved, the remaining samples were removed, dried, and recorded to determine the disintegration percentage. Table 14 describes the disintegration performance of the tested foam samples in the IC and HC tests. The foam samples containing the composition of the present invention with a flow aid exhibited higher disintegration levels in both the IC and HC tests than the control samples without any flow aids.

[0160] Table 14. Disintegration of foam samples in ISO 20200 industrial and household composting tests.

[0161]

[0162] The claims are not limited to the disclosed embodiments. The preferred embodiments of the present invention described above are for illustrative purposes only and should not be construed as limiting the scope of the invention. Modifications to the exemplary embodiments described above can be readily made by those skilled in the art without departing from the spirit of the invention.

[0163] The inventors hereby declare that they intend to determine and evaluate the reasonable and fair scope of the invention based on the doctrine of equivalence, as it relates to any device that does not substantially deviate from but is outside the literal scope of the invention as set forth in the following claims.

Claims

1. A composition comprising: a) Cellulose esters; b) Plasticizers; and c) A flow aid comprising a salt having a melting point of 100°C to 250°C.

2. The composition according to claim 1, wherein the composition further comprises a carboxylic acid stabilizer.

3. The composition according to claim 2, wherein the carboxylic acid stabilizer is citric acid, succinic acid, adipic acid, fumaric acid, maleic acid, malic acid, lauric acid, oxalic acid, myristic acid, oleic acid, palmitic acid, stearic acid, or a combination thereof.

4. The composition according to any one of claims 2-3, wherein the carboxylic acid stabilizer is citric acid.

5. The composition according to any one of claims 2-4, wherein the carboxylic acid stabilizer is present at a level of 0.1 to 10 wt%, or 0.1 to 8 wt%, or 0.1 to 6 wt%, or 0.1 to 5 wt%, or 0.1 to 4 wt%, or 0.1 to 3 wt%, or 0.1 to 2 wt% based on the total weight of the composition.

6. The composition according to any one of claims 1-5, wherein the flow aid comprises saturated or unsaturated (C 8-28 ) Blends of fatty acid salts.

7. The composition according to any one of claims 1-6, wherein the flow aid comprises saturated or unsaturated (C 8-28 Fatty acid salts.

8. The composition according to any one of claims 1-7, wherein the salt comprises a cation selected from ammonium, imidazolium, pyridinium, pyrrolidineonium, triazolium, phosphonium, piperidinium, morpholinium, tetrazolium, pyrazolium, sulfonium, and thiazolylium ions.

9. The composition according to any one of claims 1-7, wherein the salt comprises a cation selected from Group 1 or Group 12 metal ions.

10. The composition according to claim 9, wherein the metal is selected from magnesium, aluminum, calcium, potassium, sodium and zinc.

11. The composition according to claim 10, wherein the metal is magnesium.

12. The composition according to claim 1, wherein the flow aid is magnesium stearate or magnesium palmitate.

13. The composition according to any one of claims 1-12, wherein the flow aid is present in an amount greater than 0.1 wt%, or 0.15 wt%, or 0.2 wt%, or 0.25 wt%, or 0.3 wt%, or 0.35 wt%, or 0.4 wt%, or 0.45 wt%, or 0.5 wt%, or 0.55 wt%, or 0.6 wt%, or 0.65 wt% based on the total weight of the composition.

14. The composition according to any one of claims 1-13, wherein the degree of substitution of the hydroxyl substituent of the cellulose ester ranges from 0.4 to 0.

9.

15. The composition according to any one of claims 1-14, wherein the cellulose ester is cellulose acetate, cellulose propionate acetate, or cellulose acetate butyrate.

16. The composition according to any one of claims 1-15, wherein the cellulose ester is present in 50 to 98.7 wt% based on the total weight of the composition.

17. The composition according to any one of claims 1-16, wherein the plasticizer comprises triacetin, diacetin, dibutyl terephthalate, dimethyl phthalate, diethyl phthalate, or polyethylene glycol (PEG). 200-600, dibutyl tartrate, di-2-methoxyethyl phthalate, ethyl o-benzoylbenzoate, triethylene glycol dipropionate, 1,2-epoxypropylphenyl glycol, 1,2-epoxypropyl(m-tolyl)ethylene glycol, 1,2-epoxypropyl(o-tolyl)ethylene glycol, β-oxyethyl cyclohexenecarboxylate, di(cyclohexyl)diethylene glycol, triethyl citrate, polyethylene glycol, propylene glycol, polysorbate, sucrose octaacetate, acetylated triethyl citrate, acetylated tributyl citrate, Admex, triglycerides, Scandiflex, poloxamer copolymer, polyethylene glycol succinate, diisobutyl adipate, polyvinylpyrrolidone, and tribenzoic acid glycol esters, plasticizers containing benzoates such as B The enzoflex™ plasticizer series, poly(alkyl succinates) such as poly(butyl succinate), polyethersulfone, o-toluenesulfonate, N-ethyltoluenesulfonamide, adipate-based plasticizers, soybean oil epoxides such as the Paraplex™ plasticizer series, sucrose-based plasticizers, dibutyl sebacate, glyceryl tribanoate, sucrose isobutyrate, Resolflex™ series plasticizers, triphenyl phosphate (TPP), triethyl phosphate (TEP), glycolates (e.g., ethyl phthaloyl glycolate "EPEG" and methyl phthaloyl glycolate "MPEG"), methoxy polyethylene glycol, 2,2,4-trimethylpentane-1,3-dimethylbis(2-methylpropionate) or polycaprolactone.

18. The composition according to any one of claims 1-17, wherein the plasticizer is a food-compliant plasticizer.

19. The composition according to any one of claims 1-18, wherein the plasticizer is present in 1 to 20 wt% based on the total weight of the composition.

20. A composition comprising: a) 73 to 94.7 wt% cellulose acetate; b) 5 to 20 wt% triacetin; c) 0.5 to 5 wt% magnesium palmitate or magnesium stearate; and d) 0.2 to 2 wt% citric acid, All figures are based on the total weight of the composition.

21. An article comprising the composition according to any one of claims 1-20.

22. The article of claim 21, wherein the article is a foam, granules, particles, powder, sheet or film.

23. An article comprising a composition, said composition comprising: a) 73 to 94.7 wt% cellulose acetate; b) 5 to 20 wt% triacetin; c) 0.5 to 5 wt% magnesium palmitate or magnesium stearate; and d) 0.2 to 2 wt% citric acid, All figures are based on the total weight of the composition.

24. The composition or article according to any one of claims 1-23, wherein the heat distortion temperature of the composition is greater than 50°C when tested at low pressure at 100% relative humidity (RH) according to ASTM D648 or ISO 75.

25. The composition or article according to any one of claims 1-24, wherein the composition further comprises one or more physical foaming agents, chemical foaming agents, mineral fillers, alkaline substances, pigments, secondary plasticizers and / or natural fillers.

26. The article of any one of claims 21-25, wherein the article has a density of 0.643 g / cm³. 3 When the foam is 25.4 mm × 25.4 mm × 1 mm, the article exhibits at least 50%, or at least 55%, or at least 60%, or at least 65%, or at least 70%, or at least 75%, or at least 80%, or at least 85% disintegration under industrial or home composting test conditions according to ISO 20200 standards.

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