Cellulose ester mineral particle compositions and methods of reducing molecular weight of cellulose esters in their compositions

Abstract

Disclosed herein are cellulose ester compositions comprising certain mineral particle compositions. The composition reduces the molecular weight of the cellulose ester in the composition when heated, depending on temperature, time, and mineral particulate composition loading. Methods of reducing the molecular weight of cellulose esters in a cellulose ester composition comprising the mineral particle composition are also disclosed.

Description

Background Art

[0001] Cellulose esters (CE) are valuable polymers that are useful in many plastics, film, coating, and fiber applications. CE is typically synthesized by reacting cellulose with one or more anhydrides in a solvent, hydrolyzing some of the ester groups to obtain a partially esterified product, and precipitating the product in a non-solvent. Both high molecular weight and low molecular weight cellulose esters have uses. Methods for reducing the viscosity of CE typically include the presence of mineral acids and other catalysts during the synthesis or hydrolysis steps, thereby reducing the degree of polymerization of the CE. In other words, the viscosity is altered during the CE synthesis process and prior to the final precipitation. It is also desirable to be able to modify the viscosity of the CE after it is synthesized. We have unexpectedly discovered that CE compositions including an acidic mineral additive allow for control of the CE weight average molecular weight ("MW") in a separate compounding or other thermal treatment step. w ”), and thereby control the viscosity. The M of CE in the composition w or viscosity is controlled by the temperature and duration of the heating step and the loading of the acidic mineral relative to the CE. Summary of the invention

[0002] The present application discloses a composition comprising:

[0003] (i) cellulose esters;

[0004] (ii) plasticizers; and

[0005] (iii) a mineral particle composition,

[0006] wherein when the mineral particle composition is formulated into an aqueous suspension, the aqueous suspension exhibits a pH of less than 6,

[0007] in:

[0008] The plasticizer is present in an amount of 0 to 30% by weight,

[0009] The mineral particle composition is present in an amount of 0.1 to 40% by weight,

[0010] Each is based on the total weight of the cellulose ester composition.

[0011] The present application also discloses a method for reducing the weight average molecular weight ("Mw") of cellulose ester, the method comprising:

[0012] (1) heating a composition, the composition comprising:

[0013] (i) cellulose esters; and

[0014] (ii) a mineral particle composition,

[0015] wherein when the mineral particle composition is formulated into an aqueous suspension, the aqueous suspension exhibits a pH of less than 6,

[0016] The temperature is at least 200°C,

[0017] The Mw after heating decreases by at least 5%. DETAILED DESCRIPTION

[0018] Unless otherwise noted herein or the context is clearly contradictory, the terms "a / an", "said" and similar indicators used in the context of describing the present invention (especially in the context of the following claims) should be understood to cover both the singular and the plural. The range of values ​​described herein is intended only to serve as a shorthand method for individually referring to each individual value within the range. Unless otherwise noted herein, each individual value is incorporated into this specification as if it were individually described herein. Unless otherwise noted herein or the context is clearly contradictory in other ways, all methods described herein can be performed in any suitable order. The use of any and all examples or exemplary language (e.g., "such as") provided herein is intended only to better illustrate the present invention and is not intended to limit the scope of the present invention otherwise required. The wording in this specification should not be considered to indicate that any unrequired element is necessary to practice the present invention.

[0019] The grouping of alternative elements or embodiments of the present invention disclosed herein should not be considered as limiting. Each group member may be mentioned and required individually or in any combination with other group members or other elements found in this article. It is expected that one or more group members may be included in or deleted from the group for convenience and / or patentability reasons. When any such inclusion or deletion occurs, it is considered that this specification contains a group of written descriptions that are modified to meet all Markush groups used in the attached claims.

[0020] Certain embodiments of the present invention are described herein, including the best mode known to the inventor for carrying out the present invention. Of course, after reading the foregoing description, changes to these described embodiments will become apparent to those skilled in the art. The inventor expects skilled artisans to use such changes when appropriate, and the inventor intends to practice the present invention differently from the specific description herein. Therefore, the present invention includes all modifications and equivalents of the subject matter described in the accompanying claims as permitted by applicable law herein. In addition, unless otherwise noted herein or otherwise the context is clearly contradictory, any combination of the elements described above in all possible variations is encompassed by the present invention.

[0021] In addition, patents, printed publications, journal articles and other written texts (materials cited herein) are cited many times in this specification. Each reference material is individually incorporated herein by reference in its entirety for the teachings mentioned, as long as it does not contradict any specific teaching provided herein.

[0022] It should be understood that the embodiments of the invention disclosed herein illustrate the principles of the invention. Other modifications that may be used are within the scope of the invention. Thus, by way of example (but not limitation), alternative configurations of the invention may be used according to the teachings herein. Therefore, the invention is not limited to exactly as shown and described.

[0023] The details shown herein are by way of example and are only for the purpose of illustrative discussion of the preferred embodiments of the present invention, and are presented in order to provide what is considered to be the most useful and most easily understood description of the principles and concepts of the various embodiments of the present invention. In this regard, no attempt is made to show the structural details of the present invention in a more detailed manner than is necessary for a basic understanding of the present invention, and the description in conjunction with the drawings and / or examples makes it apparent to those skilled in the art how to embody several forms of the present invention in practice.

[0024] Unless clearly and unambiguously modified in one or more instances or when the application of the meaning renders any construction meaningless or substantially meaningless, it is meant and intended that the definitions and interpretations used in this disclosure shall prevail in any future construction. In the event that the construction of a term renders it meaningless or substantially meaningless, it shall be defined according to Webster's Dictionary, 3rd edition, or a dictionary known to one of ordinary skill in the art.

[0025] Composition

[0026] The present application discloses a composition comprising: (i) cellulose ester; (ii) a plasticizer; and (iii) a mineral particle composition, wherein when the mineral particle composition is formulated into an aqueous suspension, the aqueous suspension exhibits a pH of less than 6, wherein: the plasticizer is present in an amount of 0 to 30 wt % and the mineral particle composition is present in an amount of 0.1 to 40 wt %, each based on the total weight of the cellulose ester composition.

[0027] In one embodiment or in combination with any other embodiment, the mineral particle composition comprises calcined kaolin, acidic zeolite, bentonite, smectite, montmorillonite, silica, iron (II) oxide, sphalerite, pyrite, calcined diatomaceous earth, or a combination thereof. In a class of this embodiment, the mineral particle composition comprises calcined kaolin, acidic zeolite, or calcined diatomaceous earth. In a class of this embodiment, the mineral particle composition comprises calcined kaolin. In a class of this embodiment, the mineral particle composition comprises calcined diatomaceous earth.

[0028] Calcined kaolin: White kaolin is heat treated to remove some of its hydroxyl (OH) groups. Calcined kaolin is produced by heating ultrafine natural kaolinite to high temperatures in a kiln. The calcination process increases whiteness and hardness and changes the size and shape of the kaolin particles. The calcination temperature controls many properties, including the pH of the suspension in water.

[0029] Calcined diatomaceous earth (DE) is typically treated at temperatures above 1000°C. This process changes amorphous silica to crystalline silica. This additional heat treatment produces a radical change in the composition of the opalescent silica diatom frustules. Calcination dehydrates the amorphous silica in the DE and begins its conversion to crystalline cristobalite. The heat treatment also reduces the surface area of ​​the diatoms by changing their physical form. Calcined DE may also be acid washed to reduce color and other impurities.

[0030] In one embodiment or in combination with any other embodiment, the mineral particle composition has a particle size in a range from 0.1 microns to 200 microns, 10 microns to 50 microns, or 10 microns to 40 microns.

[0031] In one embodiment or in combination with any other embodiments, the mineral particle composition is 0.1 to 30 wt%, or 0.1 to 20 wt%, 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%, or 0.1 to 1 wt%, 0.5 to 30 wt%, or 0.5 to 20 wt%, 0.5 to 10 wt%, or 0.5 to 8 wt%, or 0.5 to 6 wt%, or 0.5 to 5 wt%, or 0.5 to 4 wt%, or 0.5 to 3 wt%, or 0.5 to 2 wt%, or 0.5 to 1 wt%, 1 to 30 wt%, or 1 to 20 wt%, 1 to 10 wt%, or 1 to 8 wt%, or 1 to 6 wt%, or 1 to 5 wt%, or 1 to 4 wt%, or 1 to 3 wt%, or 1 to 2 wt%, 2 to 30 wt%, or 2 to 20 wt%, 2 to 10 wt%, or 2 to 8 wt%, or 2 to 6 wt%, or 2 to 5 wt%, or 2 to 4 wt%, or 2 to 3 wt%, 3 to 30 wt%, or 3 to 20 wt%, or 3 to 10 wt%, or 3 to 8 wt%, or 3 to 6 wt%, or 3 to 5 wt%, or 3 to 4 wt%, 4 to 30 wt%, or 4 to 20 wt%, 4 to 10 wt%, or 4 to 8 wt%, or 4 to 6 wt%, or 4 to 5 wt%, 5 to 30 wt%, or 5 to 20 wt%, 5 to 10 wt%, or 5 to 8 wt%, or 5 to 6 wt%, 6 to 30 wt%, or 6 to 20 wt%, 6 to 10 wt%, or 6 to 10 wt%, or 6 to 8 wt%, 7 to 30 wt%, or 7 to 20 wt%, or 7 to 10 wt%, or 7 to 8 wt% is present.

[0032] In one embodiment or in combination with any other embodiment, the plasticizer is present in an amount of 0 to 30 wt%, or 0 to 25 wt%, or 0 to 20 wt%, or 0 to 15 wt%, or 0 to 10 wt%, or 0 to 5 wt%, or 0 to 3 wt%, or 0 to 2 wt%, or 0 to 1 wt%, or 0.1 to 30 wt%, or 0.1 to 25 wt%, or 0.1 to 20 wt%, or 0.1 to 15 wt%, or 0.1 to 10 wt%, or 0.1 to 5 wt%, or 0.1 to 3 wt%, or 0.1 to 2 wt%, or 0.1 to 1 wt%, or 0.5 to 30 wt%, or 0.5 to 25 wt%, or 0.5 to 20 wt%, or 0.5 to 15 wt%, or 0.5 to 10 wt%, or 0.5 to 5 wt%, or 0.5 to 3 wt%, or 0.5 to 2 wt%, or 0. %, or 1 to 30 wt %, or 1 to 25 wt %, or 1 to 20 wt %, or 1 to 15 wt %, or 1 to 10 wt %, or 1 to 5 wt %, or 1 to 3 wt %, or 1 to 2 wt %, or 2 to 30 wt %, or 2 to 25 wt %, or 2 to 20 wt %, or 2 to 15 wt %, or 2 to 10 wt %, or 2 to 5 wt %, or 2 to 3 wt %, or 5 to 30 wt %, or 5 to 25 wt %, or 5 to 20 wt %, or 5 to 15 wt %, or 5 to 10 wt %, or 10 to 30 wt %, or 10 to 25 wt %, or 10 to 20 wt %, or 10 to 15 wt %, or 15 to 30 wt %, or 15 to 25 wt %, or 15 to 20 wt %, or 20 to 30 wt %, or 20 to 25 wt %, or is present at 0 wt %, i.e., without plasticizer.

[0033] In one embodiment or in combination with any other embodiments, the cellulose ester is cellulose acetate, cellulose acetate propionate, cellulose acetate butyrate, or a combination thereof.

[0034] In one embodiment or in combination with any other embodiment, the cellulose ester is cellulose acetate propionate, cellulose acetate butyrate, or a combination thereof. In a class of this embodiment, the cellulose ester is cellulose acetate propionate. In a class of this embodiment, the cellulose ester is cellulose acetate butyrate. In a class of this embodiment, the plasticizer is present at 0 wt % (i.e., no plasticizer is present). In a class of this embodiment, the plasticizer is present at 0.1 to 10 wt %.

[0035] In one embodiment or in combination with any other embodiments, the cellulose ester is cellulose acetate.

[0036] In one embodiment or in combination with any of the other embodiments, the average degree of substitution (“DS OH”) is from 0.5 to 0.9 or from 0.5 to 0.8 or from 0.5 to 0.7 or from 0.5 to 0.6 or from 0.6 to 0.9 or from 0.6 to 0.8 or from 0.6 to 0.7 or from 0.7 to 0.9 or from 0.7 to 0.8 or from 0.8 to 0.9.

[0037] In one embodiment or in combination with any other embodiment, when the composition is extruded at a die temperature of 200°C with a residence time of 1 min, the weight average molecular weight loss is less than 5%, and when the composition is extruded at a die temperature of 220°C with a residence time of 1 min, the weight average molecular weight loss is greater than 5%.

[0038] In one embodiment or in combination with any other embodiment, the composition is in the form of a pellet or a powder. In a class of this embodiment, the composition is in the form of a pellet. In a class of this embodiment, the composition is in the form of a powder.

[0039] In one embodiment or in combination with any other embodiment, the composition is in the form of a solution or suspension or a coating. In a class of this embodiment, the composition is in the form of a solution. In a class of this embodiment, the composition is in the form of a suspension. In a class of this embodiment, the composition is in the form of a coating.

[0040] In one embodiment or in combination with any other embodiment, the plasticizer is triacetin, triethyl citrate, polyethylene glycol, Benzoflex, propylene glycol, polysorbate sucrose octaacetate, acetylated triethyl citrate, acetyl tributyl citrate, Admex, tripropionin, Scandiflex, poloxamer copolymer, polyethylene glycol succinate, diisobutyl adipate, polyvinyl pyrrolidone, glycol tribenzoate, or a combination thereof.

[0041] In one embodiment or in combination with any other embodiment, the plasticizer is tris(chloroisopropyl) phosphate, tris(2-chloro-1-methylethyl) phosphate, trimethyl phosphate, triethyl phosphate, tributyl phosphate, triphenyl phosphate, tributyl o-acetyl citrate, dibutyl tartrate, ethyl o-benzoylbenzoate, n-ethyltoluenesulfonamide, o-toluenesulfonate, aromatic diols, substituted aromatic diols, aromatic ethers, tripropionin, triphenin, glycerin esters, glyceryl acetate benzoate, polyethylene glycol esters, polyethylene glycol diesters, di(2-ethylhexyl) polyethylene glycol esters, glycerol esters. ester), diethylene glycol, polypropylene glycol, polyethylene glycol diglycidyl ether, dimethyl sulfoxide, N-methylpyrrolidone, propylene carbonate, C1-020 dicarboxylic acid ester, dibutyl maleate, dioctyl maleate, resorcinol monoacetate, catechol, catechol ester, phenol, epoxy soybean oil, castor oil, linseed oil, epoxy linseed oil, polyethylene glycol-based difunctional glycidyl ether, alkyl lactone, phospholipids, 2-phenoxyethanol, acetylsalicylic acid, acetaminophen, naproxen, imidazole, Triethanolamine, benzoic acid, benzyl benzoate, salicylic acid, 4-hydroxybenzoic acid, propyl-4-hydroxybenzoate, methyl-4-hydroxybenzoate, ethyl-4-hydroxybenzoate, benzyl-4-hydroxybenzoate, tribenzoin, neopentyl dibenzoate, triethylene glycol dibenzoate, trimethylolethane tribenzoate, butylated hydroxytoluene, butylated hydroxyanisole, sorbitol, xylitol, ethylenediamine, piperidine, piperazine, hexamethylenediamine, triazine, triazole, pyrrole, or a combination thereof.

[0042] In one embodiment or in combination with any other embodiment, the plasticizer is a biodegradable plasticizer. Some examples of biodegradable plasticizers include triacetin, tripropionin, tributyrin, triphenin, mixed triglycerides, diglycerides, soybean oil epoxides such as Vikoflex and Paraplex TM Plasticizer series; triethyl citrate, acetyl triethyl citrate; polyethylene glycol (PEG), PEG esters and PEG ethers; benzoate plasticizers such as Benzoflex TM Plasticizer series, sucrose ester plasticizers; dicarboxylic acid esters and polyesters (adipate-based plasticizers, dibutyl sebacate); poly(alkyl succinates) such as poly(butyl succinate), polyethersulfones, polycaprolactones, polyester plasticizers Resoflex TM and Paraplex series and their combinations.

[0043] In one embodiment or in combination with any other embodiments, the plasticizer is triacetin, triethyl citrate, polyethylene glycol, Benzoflex, propylene glycol, polysorbate sucrose octaacetate, acetylated triethyl citrate, acetyl tributyl citrate, Admex, tripropionin, Scandiflex, poloxamer copolymer, polyethylene glycol succinate, diisobutyl adipate, polyvinyl pyrrolidone, glycol tribenzoate, or a combination thereof.

[0044] In one embodiment or in combination with any other embodiments, wherein the plasticizer is triacetin, triethyl citrate, Benzoflex, propylene glycol, polysorbate sucrose octaacetate, acetylated triethyl citrate, acetyl tributyl citrate, Admex, tripropionin, Scandiflex, poloxamer copolymer, polyethylene glycol succinate, diisobutyl adipate, polyvinyl pyrrolidone, glycol tribenzoate, or a combination thereof.

[0045] In one embodiment or in combination with any other embodiment, wherein the plasticizer is triacetin. In one embodiment or in combination with any other embodiment, the plasticizer is polyethylene glycol.

[0046] In one embodiment or in combination with any of the noted embodiments, the cellulose acetate comprises at least one recycled cellulose acetate, wherein the cellulose acetate has at least one substituent on an anhydroglucose unit (AU) derived from a recycled content material (e.g., recycled plastic content syngas).

[0047] In one embodiment or in combination with any other embodiment, the composition further comprises at least one of the following: a filler, an additive, a biopolymer, a stabilizer and / or an odor modifier. Examples of additives include waxes, extenders, biodegradation promoters, dyes, pigments, colorants, gloss control agents, lubricants, antioxidants, viscosity modifiers, antifungal agents, antifogging agents, thermal stabilizers, impact modifiers, antibacterial agents, softeners, release agents, and combinations thereof.

[0048] method

[0049] The present application discloses a method for reducing the weight average molecular weight ("Mw") of a cellulose ester, the method comprising: (1) heating a composition comprising: (i) a cellulose ester; and (ii) a mineral particle composition at a temperature of at least 200°C, wherein when the mineral particle composition is formulated into an aqueous suspension, the aqueous suspension exhibits a pH of less than 6, wherein the Mw after heating is reduced by at least 5%.

[0050] In one embodiment or in combination with any other embodiment, the heating is carried out in an extruder or a melt press. In a class of this embodiment, the heating is carried out in an extruder. In a class of this embodiment, the heating is carried out in a melt press.

[0051] In one embodiment or in combination with any other embodiments, the heating is performed for 15 seconds to 20 minutes, or 15 seconds to 10 minutes, or 15 seconds to 5 minutes, or 15 seconds to 3 minutes, or 15 seconds to 2 minutes, or 15 seconds to 1 minute, or 15 seconds to 50 seconds, or 15 seconds to 40 seconds, 15 seconds to 30 seconds, or 15 seconds to 20 seconds, or 20 seconds to 20 minutes, or 20 seconds to 10 minutes, or 20 seconds to 5 minutes, or 20 seconds to 3 minutes, or 20 seconds to 2 minutes, or 20 seconds to 1 minute, or 20 seconds to 50 seconds, or 20 seconds to 40 seconds, 20 seconds to 30 seconds, or 30 seconds to 20 minutes, or 30 seconds to 20 minutes. or 20 seconds to 1 minute, or 20 seconds to 50 seconds, or 30 seconds to 40 seconds, or 40 seconds to 20 minutes, or 40 seconds to 10 minutes, or 40 seconds to 5 minutes, or 40 seconds to 3 minutes, or 40 seconds to 2 minutes, or 40 seconds to 1 minute, or 40 seconds to 50 seconds, or 50 seconds to 20 minutes, or 50 seconds to 10 minutes, or 50 seconds to 5 minutes, or 50 seconds to 3 minutes, or 20 seconds to 2 minutes, or 20 seconds to 1 minute, or 20 seconds to 50 seconds, or 20 seconds to 40 seconds, or 20 seconds to 30 seconds.

[0052] In one embodiment or in combination with any other embodiment, the temperature is 200°C to 310°C, or 200°C to 300°C, or 200°C to 290°C, or 200°C to 280°C, or 200°C to 270°C, or 200°C to 260°C, or 200°C to 250°C, or 200°C to 240°C, or 200°C to 230°C, or 200°C to 220°C, or 200°C to 210°C, or 210°C to 310°C, or 210°C to 320°C. to 300°C, or 210°C to 290°C, or 210°C to 280°C, or 210°C to 270°C, or 210°C to 260°C, or 210°C to 250°C, or 210°C to 240°C, or 210°C to 230°C, or 210°C to 220°C, or 220°C to 310°C, or 220°C to 300°C, or 220°C to 290°C, or 220°C to 280°C, or 220°C to 270°C, or 220°C to 260°C, or 2 20°C to 250°C, or 220°C to 240°C, or 220°C to 230°C, or 240°C to 310°C, or 240°C to 300°C, or 240°C to 290°C, or 240°C to 280°C, or 240°C to 270°C, or 240°C to 260°C, or 240°C to 250°C, or 250°C to 310°C, or 250°C to 300°C, or 250°C to 290°C, or 250°C to 280°C, or 250°C to 270°C, or 2 50℃ to 260℃, or 260℃ to 310℃, or 260℃ to 300℃, or 260℃ to 290℃, or 260℃ to 280℃, or 260℃ to 270℃, or 270℃ to 310℃, or 270℃ to 300℃, or 270℃ to 290℃, or 270℃ to 280℃, or 280℃ to 310℃, or 280℃ to 300℃, or 280℃ to 290℃, or 290℃ to 310℃, or 290℃ to 300℃.

[0053] In one embodiment or in combination with any other embodiments, the Mw after heating is reduced by at least 5%, or at least 10%, or at least 15%, or at least 20%, or at least 30%, or at least 40%, or at least 50%, or at least 60%, or at least 70%, or at least 80%, or at least 90%, or from 5% to 90%, or from 5% to 80%, or from 5% to 70%, or from 5% to 60%, or from 5% to 50%, or from 5% to 40%, or from 5% to 30%, or from 5% to 20%, or from 5% to 15%, or from 5% to 10%, or from 10% to 90%, or from 10% to 80%, or from 10% to 70%, or from 10% to 60%, or from 10% to 50%, or from 5% to 40%, or from 10% to 30%, or from 10% to 20%, or from 10% to 15%, or from 5% to 90%, or from 5% to 80%, or from 5% to 70%, or from 10% to 60%, or from 10% to 50%, or from 10% to 40%, or from 10% to 30%, or from 10% to 20%, or from 10% to 15%, or from 5% to 90%, or from 5% to 80%, or from 5% to to 70%, or 5% to 60%, or 15% to 50%, or 15% to 40%, or 15% to 30%, or 15% to 20%, or 20% to 90%, or 20% to 80%, or 20% to 70%, or 20% to 60%, or 20% to 50%, or 20% to 40%, or 20% to 30%, or 30% to 90%, or 30% to 80%, or 30% to 70%, or 30% to 30% to 60%, or 30% to 50%, or 30% to 40%, or 40% to 90%, or 40% to 80%, or 40% to 70%, or 40% to 60%, or 40% to 50%, or 50% to 90%, or 50% to 80%, or 50% to 70%, or 50% to 60%, or 60% to 90%, or 60% to 80%, or 60% to 70%, or 70% to 90%, or 70% to 80%.

[0054] Example

[0055] abbreviation

[0056] CA is cellulose acetate; CAB is cellulose acetate butyrate, Ex is example; TA is triacetin; Benzoflex 50 is Eastman Benzoflex 50, PEG400 is Dow Carbowax PEG400; PEG4000 is polyethylene glycol with an average molecular weight of 4000 Da; MFR is melt flow rate; wt% is weight %; Mw is weight average molecular weight; Mn is number average molecular weight; DE is diatomaceous earth; DA is Dalton; Redtn is reduced; °C is Celsius; GPC is gel permeation chromatography; rpm is revolutions per minute; min is minute; DS is degree of substitution.

[0057] General approach

[0058] Materials: Cellulose acetate (Eastman CA398-30) with a DS of 2.4 to 2.6 and a Mw of 75,000 to 120,000 was used as CA resin. Eastman CAB 381-20 was used as cellulose mixed ester resin (Mn 70,000). Plasticizers were TA added at 10 to 20 wt%), Benzoflex 50 or Dow Carbowax PEG400. Calcined kaolin was Burgess Optiwhite P (Burgess Pigment Company). Calcined DE used was Imerys Celite 577.

[0059] Table 1. Composition

[0060] Example No. Composition 1 CA-398-30, triacetin (10 wt%) 2 CA-398-30, triacetin (10 wt%), calcined kaolin (5 wt%) 3 CA-398-30, triacetin (20 wt%), calcined kaolin (3 wt%) 4 CA-398-30, triacetin (20 wt%), calcined kaolin (5 wt%) 5 CA-398-30, PEG400 (15 wt%) 6 CA-398-30, PEG400 (15 wt%), calcined kaolin (2 wt%) 7 CA-398-30, PEG400 (15 wt%), calcined kaolin (3.5 wt%) 8 CA-398-30, PEG400 (15 wt%), calcined kaolin (5 wt%) 9 CA-398-30, PEG400 (15 wt%), calcined kaolin (10 wt%) 10 CA-394-60S, Benzoflex 50 (20 wt%), calcined kaolin (3 wt%) 11 CA-394-60S, Benzoflex 50 (20 wt%), calcined kaolin (5 wt%) 12 CAB-381-20 13 CAB-381-20, calcined kaolin (5 wt%) 14 CA-394-60S, triacetin (20 wt%), calcined kaolin (3 wt%) 15 CA-394-60S, triacetin (20 wt%), calcined kaolin (5 wt%) 16 CA-398-30, PEG4000 (15 wt%), calcined kaolin (10 wt%) 17 CA-398-30, PEG4000 (15 wt%), calcined DE (10 wt%) 18 CA-398-30, PEG4000 (5 wt%), calcined kaolin (5 wt%) 19 CA-398-30, PEG400 (15 wt%), calcined kaolin (20 wt%) 20 CA-398-30, PEG400 (15 wt%), calcined kaolin (30 wt%) 21 CA-398-30, PEG400 (15 wt%), calcined kaolin (40 wt%)

[0061] Compounding Pellets: An 18 mm Leistritz twin screw extruder with a single hole die was used to extrude the pellets which were then used for film extrusion. These pellets were made from raw materials consisting of CA resin powder, plasticizer (PEG400, Benzoflex 50 or triacetin) and optional stabilizer. Any additives except the plasticizer were added to the base powder and dry blended to produce a free flowing powder and added to a Coperion twin screw loss-in-weight feeder. The plasticizer was fed into Zone 2 by a liquid injection unit with a Witte gear pump, a Hardy 4060 controller and a syringe with a 0.020" orifice. Typical barrel temperatures at the die ranged from 90°C to about 225°C. The die temperature was about 200 to 240°C. The screw speed varied from 300 to 468 rpm. The compounded strands were passed through a water trough and pelletized using a ConAir pelletizer.

[0062] Compression Molded Films: The pellets were pre-dried in an oven at 70C for about 8 hours. Films were pressed from the dried pellets on a heated press for a total of 4 minutes with the upper and lower plates preheated to 425°F (218°C). The pre-dried pellets were applied to the center of a 4-square inch, 10 mil thick frame between the top and bottom aluminum foils (all between two steel plates). The assembly was placed in a press and heated at 0 pressure for 1 min to dry and pre-melt the material, then pressed at 12,000 PHI for 1 minute, increased to higher pressure in about 30 seconds, and finally held at 20,000 PHI for 1.5 minutes (punch force in pounds).

[0063] Extruded Films: Films were produced using a 1.5 inch Killion single screw extruder equipped with a Maddock mixing screw. Pellets were loaded into a hopper and the material was conveyed into a barrel where the Maddock screw transferred the material toward the die. The barrel (which houses the screw) was heated in three zones and the pellets melted along a very narrow gap as they passed over the screw, allowing high shear and a high degree of dispersive mixing. A uniform polymer mixture was formed as they approached the die, and the screw forced the mixture through the die where it was extruded, forming a flat molten film as the film left the die, which solidified on a temperature controlled polished chrome roller (commonly referred to as a roller set). The barrel temperature was typically in the range of 190°C to 240°C and the die temperature was 230°C to 240°C. After extrusion, the film solidified as it cooled, and samples were removed intermittently to determine the film thickness. When the extruder produces the proper film thickness, the film is attached to a take-up roll and the film is carefully rolled up until the final roll is complete.

[0064] Gel Permeation Chromatography (GPC): The molecular weight values ​​of CE are calculated as the polystyrene equivalent molecular weight of the test sample dissolved in tetrahydrofuran. The samples are separated using an Agilent series 1260 liquid chromatography system and detected by refractive index. The mobile phase is tetrahydrofuran stabilized with BHT. The standards are monodisperse polystyrene with molecular weights ranging from 4,000,000 to 580 Daltons.

[0065] Melt flow rate: The MFR value of CE was measured using an Instron semi-automatic melt flow tester at 200°C using a 2.16 iris loading. The sample was dried at 60°C for 8 hours and then loaded into the instrument. The volume of material extruded from the instrument in a certain time was measured by replacing the piston to measure the melt volume rate (MVR). The extrudate was then weighed to calculate the MFR (g / 10 min).

[0066] I. Compounding and film extrusion of CA-398-30 with triacetin and calcined kaolin

[0067] The pellets were compounded as described in the compositions in Table 2, and films were extruded from the compounded pellets at a nominal thickness of 30 mils. The addition of calcined kaolin (Optiwhite P) in Formulation 2 made the extruded film too brittle to be rolled onto a roller. GPC analysis showed that the resin Mw and Mn were lower in the compounded pellets containing 5 wt% calcined kaolin. After film extrusion, the Mw and Mn decreased further. The Mw and Mn decreases for CA-398-30 were calculated based on initial Mw and Mn equal to 116,605 and 35,062 Da, respectively.

[0068] Table 2. Pellets compositions and corresponding extruded films; and GPC results

[0069]

[0070] Ⅱ. Compounding of CA-398-30 with polyethylene glycol and calcined kaolin

[0071] The pellets were compounded as described in the compositions in Table 3 and compression molding was used to prepare films. The instrument measured the MFR of the pellets. GPC analysis showed that the resin Mw and Mn were lower in the compounded pellets containing 5 wt% calcined kaolin. Mw and Mn were further reduced after compression molding and melting under pressure to measure MFR.

[0072] Table 3. Pellets composition and corresponding extrudates; and GPC results

[0073]

[0074] III. Compounding of CA-398-30 with polyethylene glycol and calcined kaolin or calcined DE

[0075] The pellets were compounded as described in the compositions in Table 4. GPC analysis showed that the resin Mw and Mn were lower in the compounded pellets containing 5 wt% calcined kaolin. The Mw and Mn were further reduced when the pellets were re-compounded in a twin screw extruder.

[0076] Table 4. Pellets composition and corresponding extruded films; and GPC results.

[0077]

[0078] Calcined kaolin (5 wt%, or 10 wt%) or calcined DE (10 wt%) was blended with plasticized CA-398-30. Calcined kaolin or calcined DE and CA-398-30 powders were sieved together twice to disperse the minerals before adding the plasticizer. The entire blend was dried at 70°C for 16 h and then pressed. Films were pressed as described and the molding conditions were as detailed in Table 5. The CA used in this example had an Mn of 32,605 kDa.

[0079] Table 5. Composition of compression molded films and GPC results

[0080]

[0081] IV. Compounding of CA-398-30 with polyethylene glycol and calcined kaolin

[0082] The pellets were compounded as described in the compositions in Table 6. GPC analysis showed that the resin Mw and Mn were lower in the compounded pellets containing 5 wt% calcined kaolin.

[0083] Table 6. Composition and compounding conditions of pellets; and GPC results.

[0084]

[0085] V. Compounding CAB with Calcined Kaolin

[0086] Eastman CAB-381-20 was compounded with 5% Optiwhite P calcined kaolin at different temperatures from 200°C to 240°C at a constant screw speed (468 rpm). GPC showed that the calcined kaolin was effective in the Mw reduction of CAB-381-20 (Table 7). The Mw and Mn reduction of CAB-381-20 were calculated based on the initial Mw and Mn equal to 145,000 and 44,000 Da, respectively.

[0087] Table 7. Composition and compounding conditions of pellets; and GPC results.

[0088]

[0089] VI. Compounding CA-398-30 and PEG400 without calcined kaolin

[0090] CA-398-30 was compounded without calcined kaolin at different screw speeds and temperatures as a control, and there was no reduction in Mw in the absence of calcined kaolin (Table 8).

[0091] Table 8. Composition and compounding conditions of pellets; and GPC results.

[0092]

[0093] VII. Compounding CA-394-60S with Plasticizer and Calcined Kaolin at Low Temperature (Samples 29-32)

[0094] Pellets were compounded from Formulation Examples 10, 11, 14 and 15. The dry ingredients were bag blended into free flowing powders. Plasticizer was fed into Zone 2 via a liquid injection unit attached with a (Witte) gear pump, a Hardy 4060 controller and a syringe with a 0.020" orifice. The compounding strands were passed through a water trough and pelletized (using a ConAir pelletizer). The extrusion temperature was 200°C. The molecular weight of the pellets was measured by GPC as previously described and reported in Table 9 below. With the addition of 3-5% calcined kaolin, no significant molecular weight loss was observed when the formulations were processed at 200°C.

[0095] Table 9. Composition and compounding conditions of pellets; and GPC results

[0096]

[0097] VIII. Compounding at higher temperatures (materials 33-40)

[0098] The pellets produced as samples 29-32 as described in Table 9 of Section VII were reprocessed using an Xplore micro-compounder at a higher extrusion temperature. In each run, 8 grams of compounded pellets were fed and mixed at a specific temperature (220°C, or 240°C) for a specific residence time (1 min or 3 min) as described in Table 10. The molecular weight of the pellets was measured by GPC as previously described and reported in Table 10 below. The Mn and Mw reduction percentages were calculated for samples 29-32. The results show that calcined kaolin is effective in reducing molecular weight at 220°C and 240°C. Increasing the extrusion temperature, increasing the extrusion time, and increasing the calcined kaolin content all caused a higher degree of chain scission in CA.

[0099] Table 10. Composition and compounding conditions of pellets; and GPC results.

[0100]

[0101] IX. Melt Flow Rate of Compounded Materials

[0102] The MFR of the pellets produced in Sections I, IV, V, and VI was measured at 220°C, 5 kg (ASTM D1238) and the results are reported in Table 11. Samples that did not flow are listed as having an MFR equal to 0.00.

[0103] Table 11. Composition, compounding conditions and melt flow rate of compounded materials.

[0104]

[0105]

Claims

1. A composition comprising: (i) cellulose esters; (ii) plasticizers; and (iii) a mineral particle composition, wherein when the mineral particle composition is formulated into an aqueous suspension, the aqueous suspension exhibits a pH of less than 6, in: The plasticizer is present in an amount of 0 to 30% by weight, The mineral particle composition is present in an amount of 0.1 to 40% by weight, Each is based on the total weight of the cellulose ester composition.

2. The composition of claim 1, wherein the mineral particle composition comprises calcined kaolin, acidic zeolite, bentonite, smectite, montmorillonite, iron (II) oxide, sphalerite, pyrite, calcined diatomaceous earth, or a combination thereof.

3. The composition of claim 1, wherein the mineral particle composition comprises calcined kaolin or calcined diatomaceous earth.

4. A composition according to any one of claims 1 to 3, wherein the mineral particle composition is present in an amount of 0.1 to 20% by weight.

5. The composition of any one of claims 1-4, wherein the plasticizer is present in an amount of 0.1 to 30 wt%.

6. The composition of any one of claims 1-5, wherein the cellulose ester is cellulose acetate, cellulose acetate propionate, cellulose acetate butyrate, or a combination thereof.

7. The composition of claim 6, wherein the cellulose ester is cellulose acetate.

8. The composition of claim 7, wherein the plasticizer is present in an amount of 5 to 30 wt%.

9. The composition of any one of claims 1-6, wherein the cellulose ester is cellulose acetate propionate or cellulose acetate butyrate.

10. The composition of claim 9, wherein the plasticizer is present in an amount of 0.1 to 10 wt%.

11. The composition of claim 9, wherein the composition is free of plasticizers.

12. The composition according to any one of claims 1 to 11, wherein the average degree of substitution (DS) of the hydroxyl substituents of the cellulose ester is OH ”) is 0.5 to 0.

9.

13. The composition of any one of claims 1-12, wherein when the composition is extruded at a die temperature of 200°C and a residence time of 1 min, the weight average molecular weight loss is less than 5%, and when the composition is extruded at a die temperature of 220°C and a residence time of 1 min, the weight average molecular weight loss is greater than 5%.

14. The composition according to any one of claims 1 to 13, which is in the form of pellets or powder.

15. A method of reducing the weight average molecular weight ("Mw") of a cellulose ester, the method comprising: (1) heating a composition, the composition comprising: (i) the cellulose ester; as well as (ii) a mineral particle composition, wherein when the mineral particle composition is formulated into an aqueous suspension, the aqueous suspension exhibits a pH of less than 6, The temperature is at least 200°C, The Mw after heating decreases by at least 5%.

16. The method according to claim 15, wherein the heating is performed in an extruder or a melt press.

17. The method according to claim 16, wherein the heating is performed for a period of 1 minute to 10 minutes.

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