Compositions containing cellulose ester polymers and enhanced melt strength agents

Abstract

A polymer composition comprising a cellulose ester polymer in combination with at least one salt additive. The salt additive can be combined with the cellulose ester polymer in order to reduce the melt flow rate of the polymer and improve melt processing of the polymer to form a molded article.

Description

Related Applications

[0001] This application is based upon and claims priority from U.S. Provisional Patent Application Serial No. 63 / 391,079, filed on July 21, 2022, which is incorporated herein by reference. Background Art

[0002] Every year, global plastic production continues to increase. More than half of the total plastic produced each year is used to produce plastic bottles, containers, drinking straws and other disposable items. Discarded disposable plastic products (including plastic beverage bottles) are typically not recyclable and end up in landfills. In addition, many of these items are not properly handled and end up in rivers, lakes and oceans around the world.

[0003] In view of the above, those skilled in the art have attempted to produce plastic articles made of biodegradable polymers. However, many biodegradable polymers lack the physical properties and characteristics of conventional polymers (such as polypropylene and / or polyethylene terephthalate).

[0004] Cellulose esters have been proposed in the past as alternatives to some petroleum-based polymers or plastics. For example, cellulose esters are generally considered to be environmentally friendly polymers because they are recyclable, degradable, and derived from renewable resources such as wood pulp. However, problems have been encountered when melt processing cellulose ester polymers (such as cellulose acetate polymers). These polymer materials are relatively rigid and have relatively poor elongation properties.

[0005] In view of the foregoing, there exists a need for a cellulose ester polymer and / or a cellulose ester polymer composition having improved melt processing characteristics for forming molded articles having excellent mechanical and physical properties. Summary of the invention

[0006] In general, the present disclosure relates to a polysaccharide ester polymer composition, particularly a cellulose ester polymer composition, having improved melt processing properties. The polymer composition of the present disclosure is also very suitable for forming molded articles with desired mechanical properties. In addition, the polymer composition of the present disclosure can be formulated to have excellent biodegradable properties.

[0007] In one embodiment, the present disclosure relates to a polymer composition comprising a cellulose ester polymer. The cellulose ester polymer may be present in the composition in an amount greater than about 40% by weight. The cellulose ester polymer may be optionally blended with a plasticizer. According to the present disclosure, the polymer composition further contains a salt additive that contributes cations to the polymer composition. The salt additive is present in an amount sufficient to reduce the melt flow rate of the polymer composition by more than about 20% compared to the same polymer composition without the salt additive. The salt additive may include a multivalent cation having, for example, a +2 or +3 valence state. The salt additive may include a metal salt, such as a calcium salt, an iron salt, an aluminum salt, a zinc salt, a cobalt salt, a manganese salt, or a magnesium salt. Without limitation and for exemplary purposes only, the salt additive may be, for example, calcium acetate, calcium hydroxide, magnesium acetate, lime, or a mixture thereof.

[0008] The salt additive may be present in the polymer composition in an amount of about 1 ppm to about 10,000 ppm, such as about 5 ppm to about 1,200 ppm, such as about 10 ppm to about 800 ppm. In embodiments, the salt additive may be present in the polymer composition in an amount sufficient to reduce the melt flow rate of the composition by more than about 30%, such as more than about 40%, such as more than about 50%, such as more than about 60%, such as more than about 70%, such as more than about 80%. For example, when tested at 210°C and under a load of 2.16 kg, the melt flow rate of the polymer composition may be less than about 20 g / 10 min, such as less than about 18 g / 10 min, such as less than about 15 g / 10 min, such as less than about 12 g / 10 min, such as less than about 10 g / 10 min, such as less than about 8 g / 10 min.

[0009] In one embodiment, the cellulose ester polymer included in the polymer composition can have a relatively high initial melt flow rate, which is then reduced when combined with the salt additive. Although unknown, it is believed that the salt additive can cause ionic crosslinking of the cellulose ester polymer, which increases the melt flow rate. In a specific embodiment, the cellulose ester polymer has an acetyl value of about 48% to about 56%, such as greater than 50% to less than 54%, such as less than 53%.

[0010] In addition to reducing the melt flow rate, the salt additive can also provide various other benefits and advantages. For example, in one embodiment, the salt additive can be present in the polymer composition in an amount sufficient to reduce the L* value of an article formed from the polymer composition.

[0011] In one aspect, the cellulose ester polymer can be present in the polymer composition in an amount of about 55% by weight to about 95% by weight, and the plasticizer can be present in an amount of about 5% by weight to about 40% by weight. Plasticizers that can be incorporated into the polymer composition include tris(chloroisopropyl) phosphate, tris(2-chloro-1-methylethyl) phosphate, glycerol, glyceryl monoacetate, triethyl citrate, triethyl acetyl citrate, phthalates, adipates, polyethylene glycol, glyceryl triacetate, glyceryl diacetate, trimethyl phosphate, triethyl phosphate, tributyl phosphate, triphenyl phosphate, tributyl o-acetyl citrate, dibutyl tartrate, o-benzoylbenzoyl phthalate, 1,2-dimethyl ... Ethyl acetate, n-ethyl toluenesulfonamide, o-tolyl p-toluenesulfonate, aromatic diols, substituted aromatic diols, polycaprolactone diols, aromatic ethers, tripropionate, glyceryl tribenzoate, glyceryl esters, glycerol tribenzoate, glycerol acetate benzoate, polyethylene glycol, polyethylene glycol esters, polyethylene glycol diesters, di-2-ethylhexyl polyethylene glycol esters, glycerol esters, diethylene glycol, polypropylene glycol, polyglycol diglycidyl ether, dimethyl sulfoxide Sulfone, N-methylpyrrolidone, propylene carbonate, C1-C20 dicarboxylic acid esters, dibutyl maleate, dioctyl maleate, resorcinol monoacetate, catechol, catechol esters, phenols, epoxidized soybean oil, castor oil, linseed oil, epoxidized linseed oil, difunctional glycidyl ether based on polyethylene glycol, alkyl lactone, phospholipids, 2-phenoxyethanol, acetylsalicylic acid, acetaminophen, naproxen, imidazole, triethanolamine, benzoic acid, benzyl 4-hydroxybenzoic acid, propyl 4-hydroxybenzoate, methyl 4-hydroxybenzoate, ethyl 4-hydroxybenzoate, benzyl 4-hydroxybenzoate, glyceryl tribenzoate, neopentyl dibenzoate, triethylene glycol dibenzoate, trimethylolethane tribenzoate, butylated hydroxytoluene, butylated hydroxyanisole, sorbitol, xylitol, ethylenediamine, piperidine, piperazine, hexamethylenediamine, triazine, triazole, pyrrole, and mixtures thereof.

[0012] In one aspect, the plasticizer included in the polymer composition is glycerol triacetate, polyethylene glycol, polycaprolactone diol, or a mixture thereof. In one aspect, the cellulose ester polymer may consist essentially of cellulose diacetate.

[0013] The cellulose ester polymer composition can also contain various other additives and components. For example, the composition can further include antioxidants, stabilizers, organic acids, oils, filler particles, glass fibers, bio-based polymers other than cellulose esters, biodegradable reinforcing agents, foaming agents, or mixtures thereof. The composition can also contain mineral fillers, such as talcum, calcium carbonate, metal oxides, mica, or mixtures thereof. The polymer composition can also contain a colorant, which can be a dye, a pigment, or a mixture thereof.

[0014] In one embodiment, the polymer composition is combined in a heated extruder or mixer and then extruded into strands, which can then be cut into pellets. These pellets can then be used to produce various molded products. As an example, the polymer composition can be used to produce beverage holders, drinking straws, hot beverage cans, automotive interior parts, household appliance parts, medical device components, packaging materials, etc.

[0015] Other features and aspects of the disclosure are discussed in more detail below. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The full and enabling disclosure of the present disclosure is more particularly set forth in the remainder of the specification, including with reference to the accompanying drawings, in which: Figure 1 is a perspective view of a drinking straw that may be made according to the present disclosure; Figure 2 is a cross-sectional view of a beverage holder that may be made according to the present disclosure; Figure 3 is a side view of one embodiment of a beverage can that may be made according to the present invention; Figure 4 is a cross-sectional view of a beverage bottle that can be made according to the present disclosure; Figure 5 is a perspective view of an automobile interior illustrating various articles that may be made in accordance with the present disclosure; Figure 6 is a perspective view of tableware made according to the present disclosure; Figure 7 is a perspective view of a lid made in accordance with the present disclosure; Figure 8 is a perspective view of a container made according to the present disclosure; Fig. 9 One embodiment of a medical device comprising a composition prepared according to the present disclosure is shown; Fig.10 Another embodiment of a medical device comprising a composition prepared according to the present disclosure is shown; Fig.11 Still another embodiment of a medical device comprising a composition prepared according to the present disclosure is shown; and Fig.12 Another embodiment of a medical device comprising a composition prepared according to the present disclosure is shown.

[0017] Repeat use of reference characters in the present specification and drawings is intended to represent same or analogous features or elements of the invention. DETAILED DESCRIPTION

[0018] Those skilled in the art will appreciate that this discussion is merely a description of exemplary embodiments and is not intended to limit the broader aspects of the present disclosure.

[0019] In general, the present disclosure relates to a polymer composition containing polysaccharide ester polymers such as cellulose ester polymers with improved melt processing characteristics. The molded articles made of the polymer composition can have improved physical properties. In addition, the polymer composition of the present disclosure can be formulated to have enhanced sustainability and have a faster biodegradable rate than conventional cellulose ester polymer products. The polymer composition can be used to form all different types of products using any suitable molding technology (such as extrusion, injection molding, etc.). The polymer composition of the present disclosure is particularly well formulated for any of the above methods.

[0020] In one aspect, the polymer composition of the present disclosure relates to a polymer composition containing a cellulose ester polymer having a carefully controlled degree of acetylation combined with a relatively low melt flow rate or in combination with various other properties. In another aspect, the polymer composition of the present disclosure contains a cellulose ester polymer such as a cellulose acetate polymer, in combination with a salt additive and optionally a plasticizer. The salt additive of the present disclosure is combined with the cellulose ester polymer in an amount sufficient to reduce the melt flow rate of the polymer composition. The salt additive can contribute cations to the polymer composition. Although unknown, it is believed that the salt additive causes ionic crosslinking of the cellulose ester polymer to reduce the melt flow rate.

[0021] For example, the salt additive can be combined with the cellulose ester polymer in an amount sufficient to reduce the melt flow rate of the polymer composition and / or the cellulose ester polymer by greater than about 20%, such as greater than about 30%, such as greater than about 40%, such as greater than about 50%, such as greater than about 60%, such as greater than about 70%, such as greater than about 80%. For example, the melt flow rate can be reduced by even greater than about 90%, such as greater than about 95%, and up to about 99.8%.

[0022] Generally, any suitable cellulose ester polymer can be incorporated into the polymer compositions of the present disclosure. In one aspect, the cellulose ester polymer is cellulose acetate.

[0023] Cellulose acetate can be formed by esterifying cellulose after activating cellulose with acetic acid. Cellulose can be obtained from many types of cellulosic materials, including but not limited to plant-derived biomass, corn stalks, sugar cane stems, bagasse and sugar cane residues, rice and wheat straw, agricultural grasses, hardwood, hardwood pulp, softwood, softwood pulp, cotton linters, switchgrass, bagasse, herbaceous plants, recycled paper, waste paper, wood chips, pulp and paper waste, waste wood, thin wood, willow, poplar, perennial grass (e.g., grass of the family Miscanthaceae), bacterial cellulose, seed shells (e.g., soybean), corn stalks, husks, and other forms of wood, bamboo, soybean hulls, bast fibers (such as kenaf, hemp, jute and flax), agricultural residual products, agricultural waste, livestock excrement, microorganisms, algal cellulose, seaweed and all other materials close to or ultimately derived from plants. Such cellulosic raw materials are preferably processed into pellets, chips, small pieces, sheets, ground fibers, powder forms, or other forms that make them suitable for further purification.

[0024] In some embodiments, cellulose esters suitable for use in producing the compositions of the present disclosure may have ester substituents including, but not limited to, C1-C 20 Aliphatic esters (e.g., acetates, propionates, or butyrates), functional C1-C 20 Aliphatic esters (eg, succinate, glutarate, maleate), aromatic esters (eg, benzoate or phthalate), substituted aromatic esters, and the like, any derivatives thereof, and any combination thereof.

[0025] The cellulose acetate used in the composition can be cellulose diacetate or cellulose triacetate. In one embodiment, the cellulose acetate comprises primarily cellulose diacetate. For example, the cellulose acetate can contain less than 1% by weight of cellulose triacetate, such as less than about 0.5% by weight of cellulose triacetate. The cellulose diacetate can constitute greater than 90% by weight of the cellulose acetate, such as greater than about 95% by weight of the cellulose acetate, such as greater than about 98% by weight, such as greater than about 99% by weight.

[0026] Typically, cellulose acetate can have a molecular weight greater than about 10,000 g / mol, such as greater than about 20,000 g / mol, such as greater than about 30,000 g / mol, such as greater than about 40,000 g / mol, such as greater than about 50,000 g / mol. The molecular weight of cellulose acetate is typically less than about 800,000 g / mol, such as less than about 600,000 g / mol, such as less than about 200,000 g / mol, such as less than about 150,000 g / mol, such as less than about 100,000 g / mol, such as less than about 90,000 g / mol, such as less than about 70,000 g / mol, such as less than about 50,000 g / mol. The molecular weight determined above is a number average molecular weight. The molecular weight can be determined using gel permeation chromatography using polystyrene equivalents or standards.

[0027] The cellulose ester polymer or cellulose acetate may have an initial intrinsic viscosity generally from about 0.2 dL / g to about 2 dL / g, including all increments of 0.1 dL / g therebetween.

[0028] The intrinsic viscosity can be measured by forming a solution of 0.20 g / dL cellulose ester in 98 / 2 wt / wt acetone / water and measuring the flow time of the solution and solvent in a #25 Cannon-Ubbelohde viscometer at 30° C. The intrinsic viscosity (“IV”) can then be determined using the modified Baker-Philippoff equation, which for this solvent system is Equation 1. in t1 = average flow time (seconds) of solution (with cellulose ester), t2 = average flow time (seconds) of solvent, k = solvent constant (10 for 98 / 2 wt / wt acetone / water), and c = concentration (0.200 g / dL).

[0029] The cellulose ester polymer contained in the polymer composition can be characterized by its acetyl value or degree of acetylation measured as a percentage. The acetyl value is related to the degree of substitution and provides information about the amount of acetic acid released from the cellulose ester polymer by saponification. The acetyl value can be measured according to ASTM test D871-96 (2004). In one embodiment, ASTM test D871-96 can be modified by replacing acetyl (42 molecular weight) with acetic acid (60 molecular weight) when calculating the acetyl value.

[0030] Typically, the cellulose ester polymer can have an acetyl value of from about 48% to about 68% (percent bound acetic acid), including all increments of 0.1% therebetween. In one aspect, the acetyl value can be greater than about 54%, such as greater than about 55%, such as greater than about 56%, and typically less than about 65%, such as less than about 63%.

[0031] In a specific embodiment, the cellulose ester polymer has a relatively low acetyl value. For example, the cellulose ester polymer can have an acetyl value greater than about 48%, such as greater than about 49%, such as greater than about 50%, such as greater than about 51%, and less than about 56%, such as less than about 55%, such as less than about 54%, such as less than about 53%. In the past, cellulose ester polymers with relatively low acetyl values ​​were difficult to melt process and were formed into molded products using injection molding, blow molding, etc. When combined with a plasticizer, cellulose ester polymers with relatively low acetyl values ​​tend to have very high melt flow rates. When trying to not only mold the composition into a product, a high melt flow rate may cause problems, but may also affect the stability of the final product. However, according to the present disclosure, cellulose ester polymers with relatively low acetyl values ​​can be combined with salt additives to significantly and significantly reduce the melt flow rate without damaging any other characteristics of the cellulose ester polymer or the product made of the polymer composition. In fact, compared with products made from cellulose ester polymers with higher acetyl values, products made from cellulose ester polymers with relatively low acetyl values ​​according to the present disclosure can be more rapidly biodegradable.

[0032] In a specific embodiment, for example, a polymer composition containing a cellulose ester polymer having a relatively low acetyl value as described above and combined with a plasticizer in an amount of about 5% to about 40% by weight, such as about 12% to about 28% by weight, can have a melt flow rate of less than about 20 g / 10 min, such as less than about 18 g / 10 min, such as less than about 15 g / 10 min, such as less than about 12 g / 10 min, such as less than about 10 g / 10 min, such as less than about 8 g / 10 min, when tested at 210° C. and under a load of 2.16 kg. As used herein, unless otherwise indicated, melt flow rate is determined according to ASTM test D1238-13 at a temperature of 210° C. and under a load of 2.16 kg.

[0033] Other cellulose ester polymer compositions formulated according to the present disclosure may also have a melt flow rate of less than about 20 g / 10 min, such as less than about 18 g / 10 min, such as less than about 15 g / 10 min, such as less than about 12 g / 10 min, such as less than about 10 g / 10 min, such as less than about 8 g / 10 min, such as less than about 6 g / 10 min, such as less than about 4 g / 10 min, such as less than about 2 g / 10 min, when tested at 210°C and under a load of 2.16 kg.

[0034] Typically, the cellulose ester polymer is present in the polymer composition in an amount of about 15% by weight to about 95% by weight, including all increments of 1% by weight therebetween. Cellulose acetate is typically present in the polymer composition in an amount greater than about 15% by weight, such as greater than about 25% by weight, such as greater than about 35% by weight, such as greater than about 45% by weight, such as greater than about 55% by weight, such as greater than about 65% by weight, such as greater than about 75% by weight, such as greater than about 85% by weight. Cellulose acetate is typically present in the polymer composition in an amount less than about 90% by weight, such as less than about 85% by weight, such as less than about 75% by weight, such as less than about 70% by weight, such as less than about 65% by weight.

[0035] According to the present disclosure, polysaccharide ester polymer or cellulose ester polymer is combined with at least one salt additive. As mentioned above, the salt additive can be added to the polymer composition in an amount sufficient to reduce the melt flow rate of the composition. The salt additive can also affect various other characteristics of the polymer composition or the molded product made of the composition. For example, it is believed that the cellulose ester polymer and the salt additive combination can also increase mechanical strength, such as tensile strength and modulus. It is believed that the addition of the salt additive can also increase the flexural temperature (DTUL) of the polymer composition.

[0036] In one aspect, the salt additive included in the polymer composition is a salt that can provide a cation for combination with a cellulose ester polymer. In one embodiment, the salt additive includes a salt with +2 or +3 cations. In one embodiment, the salt additive can be a metal salt. The salt additive can be, for example, a magnesium salt, a calcium salt, an iron salt, an aluminum salt, a zinc salt, a cobalt salt, or a manganese salt. In one aspect, the salt additive is water-soluble or at least partially dissociated in water at 25°C. The salt additive can be an inorganic salt or an organic salt. As used herein, a water-soluble solute is soluble in water if more than 1 gram can be dissolved in 100 mL of water at 25°C.

[0037] Examples of salt additives that can be used according to the present disclosure include calcium acetate, ferrous acetate, ferrous acetate, magnesium acetate, zinc acetate, cobalt acetate, manganese acetate, calcium hydroxide, magnesium hydroxide, lime, or a mixture thereof. Other examples of calcium salts that can be used include calcium sulfate, calcium bicarbonate, calcium bromate, calcium bromide, calcium chloride, calcium nitrate, calcium perchlorate, calcium propionate, carboxylic acid calcium salts, calcium benzoate, aromatic carboxylic acid calcium salts, magnesium acetate, magnesium bromide, magnesium chlorate, magnesium nitrate, magnesium perchlorate, magnesium sulfate, magnesium thiosulfate, calcium citrate, calcium gluconate, calcium lactate, zinc acetate, cobalt acetate, manganese acetate, etc. Any combination of the above salts can also be used.

[0038] In one embodiment, the salt additive has a neutral to acidic pH. For example, when combined with water, the salt additive can have a pH of less than 8, such as less than about 7.5, such as less than about 7 and greater than about 5, such as greater than about 5.5, such as greater than about 6, such as greater than about 6.5.

[0039] The amount that salt additive is incorporated in polymer composition can depend on various factors, comprise the type and amount of cellulose ester polymer present, the type and amount of plasticizer present and the specific salt additive selected.Usually, one or more salt additives are with the amount greater than about 1ppm, as with the amount greater than about 5ppm, as with the amount greater than about 10ppm, as with the amount greater than about 20ppm, as with the amount greater than about 30ppm, as with the amount greater than about 40ppm, as with the amount greater than about 50ppm, as with the amount greater than about 75ppm, as with the amount greater than about 100ppm, as with the amount greater than about 150ppm, as with the amount greater than about 200ppm, as with the amount greater than about 250ppm, as with the amount greater than about 300ppm, as with the amount greater than about 350ppm, as with the amount greater than about 400ppm, as with the amount greater than about 500ppm incorporated in polymer composition. The one or more salt additives are typically present in the polymer composition in an amount less than about 10,000 ppm, such as in an amount less than about 8,000 ppm, such as in an amount less than about 6,000 ppm, such as in an amount less than about 4,000 ppm, such as in an amount less than about 2,000 ppm, such as in an amount less than about 1,000 ppm, such as in an amount less than about 800 ppm.

[0040] The mode that one or more salt additives are mixed in the polymer composition can also be changed according to specific application.In one embodiment, the salt additive can be first combined with the cellulose ester polymer before being mixed with one or more plasticizers.In another embodiment, one or more salt additives can be combined with the cellulose ester polymer together with the plasticizer.For example, one or more salt additives can be added in the forcing machine, extrude different components by this forcing machine.

[0041] In one embodiment, an aqueous solution containing one or more salt additives is combined with a cellulose ester polymer. For example, cellulose ester particles or flakes can be contacted with an aqueous solution containing one or more salt additives. Alternatively, an aqueous solution containing one or more salt additives can be added to an extruder during extrusion. The aqueous solution can contain one or more salt additives, and its amount is generally about 50ppm to about 50,000ppm, including all increments of 1ppm therebetween. For example, in one embodiment, the aqueous solution can contain one or more salt additives with a concentration of about 50ppm to about 2,000ppm. In an alternative embodiment, one or more salt additives of greater concentration can be incorporated into the aqueous solution, such as with an amount of about 2,000ppm to about 20,000ppm. When applied to a cellulose ester polymer in the form of an aqueous solution, the amount of the salt additive incorporated into the resulting polymer composition is generally less than the concentration contained in the aqueous solution.

[0042] The polymer composition of the present disclosure may optionally include one or more plasticizers. Plasticizers particularly well suited for use in polymer compositions include triacetin, monoacetin, diacetin, and mixtures thereof. Other suitable plasticizers include tri(chloroisopropyl) phosphate, tri(2-chloro-1-methylethyl) phosphate, triethyl citrate, triethyl acetyl citrate, glycerol, or mixtures thereof. In alternative embodiments, the plasticizer may be polyethylene glycol. In yet another embodiment, the plasticizer may be polycaprolactone.

[0043] Other examples of plasticizers include, but are not limited to, trimethyl phosphate, triethyl phosphate, tributyl phosphate, triphenyl phosphate, acetyl tributyl citrate, o-acetyl tributyl citrate, dibutyl tartrate, ethyl o-benzoylbenzoate, n-ethyl toluenesulfonamide, o-tolyl p-toluenesulfonate, aromatic diols, substituted aromatic diols, aromatic ethers, tripropionate, glyceryl tribenzoate, glycerol, glyceryl esters, glycerol tribenzoate, glycerol acetate benzoate, polyethylene glycol esters, polyethylene glycol diesters, di-2-ethylhexyl polyethylene glycol esters, glycerol esters, diethylene glycol, polypropylene glycol, polyglycol diglycidyl ether, dimethyl sulfoxide, N-methylpyrrolidone, propylene carbonate, C1-C 20dicarboxylates, dimethyl adipate (and other dialkyl esters), dibutyl maleate, dioctyl maleate, resorcinol monoacetate, catechol, catechol esters, phenols, epoxidized soybean oil, castor oil, linseed oil, epoxidized linseed oil, other vegetable oils, other seed oils, polyethylene glycol-based difunctional glycidyl ethers, alkyl lactones (e.g., γ-valerolactone), alkyl phosphates, aryl phosphates, phospholipids, fragrances (including some described herein, e.g., eugenol, cinnamyl alcohol, camphor, methoxyhydroxyacetophenone (acetyl vanilloid), vanillin and ethyl vanillin), 2-phenoxyethanol, glycol ethers, glycol esters, glycol ester ethers, polyethylene glycol ethers, polyethylene glycol esters, glycol ethers , propylene glycol ethers, ethylene glycol esters (e.g., ethylene glycol diacetate), propylene glycol esters, polypropylene glycol esters, 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, glyceryl tribenzoate, neopentyl dibenzoate, triethylene glycol dibenzoate, trimethylolethane tribenzoate, butylated hydroxytoluene, butylated hydroxyanisole, sorbitol, xylitol, ethylenediamine, piperidine, piperazine, hexamethylenediamine, triazine, triazole, pyrrole, polycaprolactone diol, and the like, any derivatives thereof, and any combination thereof.

[0044] In one aspect, carbonate can be used as plasticizer.Exemplary carbonate can include but is not limited to propylene carbonate, butylene carbonate, diphenyl carbonate, phenyl methyl carbonate, ditolyl carbonate, glycerol carbonate, dimethyl carbonate, diethyl carbonate, ethylene carbonate, propylene carbonate, isopropylphenyl 2-ethylhexyl carbonate, phenyl carbonate 2-ethylhexyl, isopropylphenyl isodecyl carbonate, isopropylphenyl tridecyl carbonate, phenyl carbonate tridecyl ester etc., and any combination thereof.

[0045] In yet another aspect, plasticizer can be polyol benzoate.Exemplary polyol benzoate can include but is not limited to glyceryl tribenzoate, propylene glycol dibenzoate, diethylene glycol dibenzoate, dipropylene glycol dibenzoate, triethylene glycol dibenzoate, sucrose benzoate, polyethylene glycol dibenzoate, neopentyl glycol dibenzoate, trimethylolpropane tribenzoate, trimethylolethane tribenzoate, pentaerythritol tetrabenzoate, sucrose benzoate (with a degree of substitution of 1-8) and combination thereof.In some cases, tribenzoate like glyceryl tribenzoate can be preferred.In some cases, polyol benzoate can be solid at 25 ℃, and water solubility at 25 ℃ is less than 0.05g / 100mL.

[0046] Plasticizers can also be bio-based. For example, the use of bio-based plasticizers can make the polymer composition well suited for contact with food items. Bio-based plasticizers particularly well suited for the compositions of the present disclosure include alkyl ketal esters, non-petroleum hydrocarbon esters, bio-based polymers or oligomers such as polycaprolactones with a number average molecular weight of 1000 or less, or mixtures thereof.

[0047] In one aspect, the bio-based plasticizer is an alkyl ketal ester having a chemical structure corresponding to Structure I as provided below: Where a is 0 to 12; b is 0 or 1; each R 1 are independently hydrogen, hydrocarbyl, or substituted hydrocarbyl; each R 2 , R 3 and R 4 are independently methylene, alkylmethylene, or dialkylmethylene, x is at least 1, y is 0 or a positive number, and x+y is at least 2; R 6 is a hydrocarbyl or substituted hydrocarbyl group, and each Z is independently -O-, -NH-, or -NR-, wherein R is a hydrocarbyl or substituted hydrocarbyl group.

[0048] The plasticizers identified above correspond to the reaction products of certain 1,2- and / or 1,3-alkanediol ketals of polyols, amino alcohols or polyamines with oxocarboxylates. The 1,2- and 1,3-alkanediol ketals of oxocarboxylates are referred to herein as "alkyl ketal esters". Up to one mole of alkyl ketal ester may be reacted per equivalent of hydroxyl or amino groups provided by the polyol, amino alcohol or polyamine. The polyol, amino alcohol or polyamine is most preferably difunctional, but polyols, amino alcohols and polyamines having more than two hydroxyl and / or amino groups may be used.

[0049] The values ​​of x and y in Structure I will depend on the number of hydroxyl or amino groups on the polyol, amino alcohol or polyamine, the number of moles of alkyl ketal ester per mole of polyol, amino alcohol or polyamine, and the extent to which the reaction has been carried out to completion. Higher amounts of alkyl ketal ester favor lower values ​​of y and higher values ​​of x.

[0050] In Structure I, y is specifically 0 to 2, and x is specifically at least 2. All a in Structure I are specifically 2 to 12, more specifically 2 to 10, more specifically 2 to 8, more specifically 2 to 6, more specifically 2 to 4, and more specifically 2. All R 1 In some embodiments of Structure I, all Z are -O-, y is 0 and x is 2; these products correspond to the reaction of two moles of alkyl ketal ester and one mole of diol. In some other embodiments, all Z are -O-, y is 1 and x is 1; these products correspond to the reaction of one mole of alkyl ketal ester and one mole of diol.

[0051] In one embodiment, all b's are 0. In another embodiment, all b's are 1.

[0052] Some specific compounds according to Structure I include those having the following structures: or structure or structure In particular, where R 6 Yes -(CH2)- m , wherein m is 2 to 18, especially 2, 3, 4 or 6. In a particular embodiment, R 6 Corresponding to the residue after removal of the hydroxyl group of 1,4-butanediol, the structure (Ia) is obtained

[0053] In another specific embodiment, R 6 Corresponding to the residue after removal of the hydroxyl group of diethylene glycol, the structure (Ib) is obtained

[0054] In another specific embodiment, R 6 Corresponding to the residue after removal of the hydroxyl group of 2-methyl-1-3-propanediol, the structure (Ic) is obtained

[0055] The compounds according to structure I can be prepared in a transesterification or ester-aminolysis reaction between the corresponding polyols, amino alcohols or polyamines and the corresponding alkyl ketal esters. Alternatively, the compounds according to structure I can be prepared by reacting an oxocarboxylic acid with a polyol, amino alcohol or polyamine to form an ester or amide, and then ketalizing the resulting product with a 1,2- or 1,3-alkanediol (e.g., ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 2-methyl-1-3 propanediol, 1,2-butylene glycol, 1,3-butylene glycol, 1,2-pentanediol, 1,3-pentanediol, 1,2-hexanediol, 1,3-hexanediol, polycaprolactone diol, etc.).

[0056] Alkyl ketal ester plasticizers are particularly well suited for use in combination with one or more other plasticizers. For example, in one aspect, an alkyl ketal ester plasticizer can be combined with a benzoate. The weight ratio between the two plasticizers can vary, such as from about 1:10 to about 10:1, such as from about 1:4 to about 4:1.

[0057] Another bio-based plasticizer that can be incorporated into the polymer composition of the present disclosure is a non-petroleum hydrocarbon ester. For example, an example of a non-petroleum hydrocarbon ester is sold by the Hall Star Company in Chicago, Illinois under the trade name HALLGREEN. For example, a non-petroleum hydrocarbon ester plasticizer can contain a bio-based content greater than about 50% by weight, such as greater than about 70% by weight, such as greater than about 99% by weight. For example, these esters can be mainly derived from agriculture, forestry, or marine materials and are therefore biodegradable. In one aspect, a non-petroleum hydrocarbon ester plasticizer has about 1.16 or greater at 25°C, such as about 1.165 or greater, such as about 1.17 or greater, such as about 1.74 or greater, and generally about 1.19 or less, such as about 1.185 or less, such as about 1.18 or less, such as about 1.78 or less specific gravity. The non-petroleum hydrocarbon ester plasticizer may have an acid value of about 0.5 mgKOH / g to about 0.6 mgKOH / g, such as about 0.53 mgKOH / g to about 0.57 mgKOH / g.

[0058] In another aspect, the polymer composition contains a bio-based plasticizer, which is a bio-based polyester, such as a bio-based aliphatic polyester with a relatively low molecular weight. For example, the plasticizer can include a bio-based polyester polymer having a number average molecular weight of less than about 1000, such as less than about 900, such as less than about 800, and generally greater than about 500. In one embodiment, the bio-based plasticizer is a polycaprolactone having a number average molecular weight of 1000 or less. Alternatively, the bio-based plasticizer can be a polyhydroxyalkanoate having a number average molecular weight of 10,000 or less, such as polyhydroxybutyrate.

[0059] In one aspect, the plasticizer is phthalate-free. In fact, the polymer composition can be formulated to be phthalate-free. For example, the phthalate can be present in the polymer composition in an amount of about 0.5% or less, such as in an amount of about 0.1% or less.

[0060] Typically, one or more plasticizers may be present in the polymer composition in an amount of about 3% to about 40% by weight, such as in an amount of about 8% to about 35% by weight. However, in the past, it was believed that relatively large amounts of plasticizers were required in order to produce a cellulose acetate composition that could be melt processed. However, the amount of plasticizer can be reduced without compromising the melt processing characteristics of the composition. For example, in one aspect, one or more plasticizers may be present in the polymer composition in an amount of about 19% or less, such as in an amount of about 17% or less, such as in an amount of about 15% or less, such as in an amount of about 13% or less, such as in an amount of about 10% or less. One or more plasticizers are typically present in an amount of about 3% or more, such as in an amount of about 5% or more.

[0061] The cellulose acetate may be present relative to the plasticizer such that the weight ratio between the cellulose acetate and the one or more plasticizers is from about 60:40 to about 95:5, such as from about 70:30 to about 90:10.

[0062] In addition to polysaccharide ester polymers, one or more salt additives and optionally one or more plasticizers, the polymer composition of the present disclosure can contain various other additives and ingredients. For example, cellulose acetate, one or more plasticizers and one or more salt additives can also be combined with one or more bio-based polymers different from cellulose acetate and one or more plasticizers. As used herein, "bio-based" polymers or plasticizers refer to polymers, oligomers, or compounds produced from at least part of a renewable biomass source, such as from plant matter or food waste. For example, bio-based polymers can be polymers produced from renewable resources greater than 30%, such as greater than about 40%, such as greater than about 50%, such as greater than about 60%, such as greater than about 70%, such as greater than about 80%, such as greater than about 90%. Bio-based polymers should be distinguished from polymers derived from fossil resources such as petroleum. Bio-based polymers can be biologically derived, meaning that polymers are derived from biological sources or produced via biological reactions (such as by fermentation or other microbial processes). Although cellulose ester polymers can be considered bio-based polymers, the term herein refers to other bio-based materials that can be combined with the cellulose ester polymers. The bio-based polymers can also be biodegradable.

[0063] In one aspect, the bio-based polymer can be a polyester polymer, such as an aliphatic polyester. Specific bio-based polymers that can be incorporated into the polymer composition include polyhydroxyalkanoates, polylactic acid, polycaprolactone, or mixtures thereof.

[0064] In one aspect, at least one bio-based polymer combined with cellulose acetate is a polyhydroxyalkanoate. The polyhydroxyalkanoate can be a homopolymer or a copolymer. Polyhydroxyalkanoates (also known as "PHAs") are linear polyesters produced in nature by bacterial fermentation of sugars or lipids. In this family, more than 100 different monomers can be combined to obtain materials with extremely different properties. Typically, they can be thermoplastic or elastomeric materials with melting points ranging from 40°C to 180°C. The most common type of PHA is PHB (poly-β-hydroxybutyrate). Poly (3-hydroxybutyrate) (PHB) is a naturally occurring thermoplastic polymer currently produced by microorganisms inside the cell wall of many wild bacterial species or genetically modified bacteria or yeasts. It is biodegradable and does not cause environmental problems after treatment, i.e., products made of PHB can be composted.

[0065] The monomer or monomers used to produce the PHA can significantly affect the physical properties of the polymer. For example, crystalline, semi-crystalline, or fully amorphous PHAs can be produced. For example, poly-4-hydroxybutyrate homopolymers can be fully amorphous, having a glass transition temperature of less than about -30°C and no distinct melting point temperature. Polyhydroxybutyrate-valerate copolymers can also be formulated to be semi-crystalline to amorphous, with low stiffness characteristics.

[0066] Examples of monomer units that can be incorporated into PHA include 2-hydroxybutyrate, glycolic acid, 3-hydroxybutyrate (hereinafter referred to as 3HB), 3-hydroxypropionate (hereinafter referred to as 3HP), 3-hydroxyvalerate (hereinafter referred to as 3HV), 3-hydroxyhexanoate (hereinafter referred to as 3HH), 3-hydroxyheptanoate (hereinafter referred to as 3HH), 3-hydroxyoctanoate (hereinafter referred to as 3HO), 3-hydroxynonanoate (hereinafter referred to as 3HN), 3-hydroxydecanoate (hereinafter referred to as 3HD), 3-hydroxydodecanoate (hereinafter referred to as 3HDd), 4-hydroxybutyrate (hereinafter referred to as 4HB), 4-hydroxyvalerate (hereinafter referred to as 4HV), 5-hydroxyvalerate (hereinafter referred to as 5HV), and 6-hydroxyhexanoate (hereinafter referred to as 6HH). The 3-hydroxy acid monomer incorporated into PHA is a (D) or (R) 3-hydroxy acid isomer, except for 3HP which does not have a chiral center.

[0067] In some embodiments, the PHA in the methods described herein is a homopolymer (wherein all monomer units are the same). Examples of PHA homopolymers include poly 3-hydroxyalkanoates (e.g., poly 3-hydroxypropionate (hereinafter referred to as P3HP)), poly 3-hydroxybutyrate (hereinafter referred to as P3HB) and poly 3-hydroxyvalerate, poly 4-hydroxyalkanoates (e.g., poly 4-hydroxybutyrate (hereinafter referred to as P4HB)), poly 4-hydroxyvalerate (hereinafter referred to as P4HV)) or poly 5-hydroxyalkanoates (e.g., poly 5-hydroxyvalerate (hereinafter referred to as P5HV)).

[0068] In certain embodiments, PHA may be a copolymer (containing two or more different monomer units) in which different monomers are randomly distributed in the polymer chain. Examples of PHA copolymers include poly 3-hydroxybutyrate-co-3-hydroxypropionate (hereinafter referred to as PHB3HP), poly 3-hydroxybutyrate-co-4-hydroxybutyrate (hereinafter referred to as P3HB4HB), poly-3-hydroxybutyrate-co-4-hydroxyvalerate (hereinafter referred to as PHB4HV), poly 3-hydroxybutyrate-co-3-hydroxyvalerate (hereinafter referred to as PHB3HV), poly 3-hydroxybutyrate-co-3-hydroxyhexanoate (hereinafter referred to as PHB3HH) and poly 3-hydroxybutyrate-co-5-hydroxyvalerate (hereinafter referred to as PHB5HV).

[0069] Examples of PHAs with 4 different monomer units would be PHB-co-3HH-co-3HO-co-3HD or PHB-co-3-HO-co-3HD-co-3HDd. Typically, in the case of PHB3HX having 3 or more monomer units, the 3HB monomer is at least 70% by weight of the total monomers, such as greater than 90% by weight of the total monomers.

[0070] When present, the one or more PHAs can be included in the polymer composition in an amount of about 2% or more, such as about 3% or more, such as about 5% or more, such as about 7% or more, such as about 10% or more, such as about 12% or more, such as about 15% or more, such as about 18% or more. The one or more PHAs are typically present in the polymer composition in an amount of about 30% or less, such as about 25% or less, such as about 20% or less, such as about 15% or less.

[0071] In addition to one or more PHAs, the polymer composition may contain various other bio-based polymers, such as polylactic acid or polycaprolactone. Polylactic acid (also known as "PLA") is well suited for combination with one or more PHAs. Polylactic acid polymers are typically more rigid and harder than PHAs, and therefore can be added to the polymer composition to further improve the properties of the overall formulation.

[0072] Polylactic acid can be generally derived from monomer units of any isomer of lactic acid, such as left-lactic acid ("L-lactic acid"), right-lactic acid ("D-lactic acid"), meso-lactic acid, or a mixture thereof. The monomer units can also be formed by anhydrides of any isomer of lactic acid (including L-lactide, D-lactide, meso-lactide, or a mixture thereof). Cyclic dimers of such lactic acid and / or lactide can also be used. Any known polymerization method can be used, such as polycondensation or ring-opening polymerization to polymerize lactic acid. A small amount of chain extender (e.g., diisocyanate compounds, epoxy compounds, or anhydrides) can also be used. Polylactic acid can be a homopolymer or a copolymer, such as a copolymer containing monomer units derived from L-lactic acid and monomer units derived from D-lactic acid. Although not required, the content of one of the monomer units derived from L-lactic acid and the monomer units derived from D-lactic acid is preferably about 85 mol% or greater, in some embodiments about 90 mol% or greater, and in some embodiments about 95 mol% or greater. A plurality of polylactic acids (each having a different ratio between the monomer units derived from L-lactic acid and the monomer units derived from D-lactic acid) can be blended at any percentage.

[0073] In one specific embodiment, polylactic acid has the following general structure:

[0074] The number average molecular weight (“Mn The weight average molecular weight ("M") of the polymer is typically in the range of about 40,000 to about 160,000 g / mole, in some embodiments, about 50,000 to about 140,000 g / mole, and in some embodiments, about 80,000 to about 120,000 g / mole. Similarly, the weight average molecular weight ("M") of the polymer is typically in the range of about 40,000 to about 160,000 g / mole, in some embodiments, about 50,000 to about 140,000 g / mole, and in some embodiments, about 80,000 to about 120,000 g / mole. w The ratio of weight average molecular weight to number average molecular weight ("M w / M n ”), i.e., the “polydispersity index”, is also relatively low. For example, the polydispersity index typically ranges from about 1.0 to about 3.0, in some embodiments from about 1.1 to about 2.0, and in some embodiments from about 1.2 to about 1.8. The weight average molecular weight and number average molecular weight can be determined by methods known to those skilled in the art.

[0075] The polylactic acid can be present in the polymer composition in an amount of about 1% or more, such as about 3% or more, such as about 5% or more, and typically in an amount of about 20% or less, such as about 15% or less, such as about 10% or less, such as about 8% or less.

[0076] As described above, another bio-based polymer that can be combined with cellulose acetate alone or in combination with other bio-based polymers is polycaprolactone having a higher molecular weight than the polycaprolactone plasticizer. Similar to PHA, polycaprolactone can be formulated to have a relatively low glass transition temperature. The glass transition temperature can be, for example, less than about 10°C, such as less than about -5°C, such as less than about -20°C, and typically greater than about -60°C. These polymers can be produced to be amorphous or semi-crystalline. The crystallinity of the polymer can be less than about 50%, such as less than about 25%.

[0077] Polycaprolactones can be prepared having number average molecular weights generally greater than about 5,000, such as greater than about 8,000, and generally less than about 15,000, such as less than about 12,000.

[0078] The polycaprolactone can be included in the polymer composition in an amount of about 2% or more, such as about 3% or more, such as about 5% or more, such as about 7% or more, such as about 10% or more, such as about 12% or more, such as about 15% or more, such as about 18% or more. The polycaprolactone is typically present in the polymer composition in an amount of about 30% or less, such as about 25% or less, such as about 20% or less, such as about 15% or less.

[0079] Other bio-based polymers that can be incorporated into the polymer composition include polybutylene succinate, polybutylene adipate terephthalate, plasticized starch, other starch-based polymers, etc. In addition, the bio-based polymer can be a polyolefin or polyester polymer made from renewable resources. For example, such polymers include bio-based polyethylene, bio-based polybutylene terephthalate, etc.

[0080] In one aspect, acid scavengers also can be present in the polymer composition. Acid scavengers can be carbonates, oxides, amines or mixtures thereof. The example of acid scavengers comprises zinc oxide, magnesium oxide, sodium aluminum carbonate, aluminum silicate, hydrotalcite or mixtures thereof. One or more acid scavengers can be generally greater than about 0.1% by weight, such as greater than about 0.5% by weight, such as greater than about 1% by weight, and generally less than about 2.5% by weight, such as less than about 2% by weight, such as less than about 1.5% by weight and present in the polymer composition.

[0081] The polymer composition may also include antioxidants, pigments, lubricants, softeners, antibacterial agents, antifungal agents, preservatives, flame retardants, and combinations thereof. Each of the above additives may typically be present in the polymer composition in an amount of about 5% or less, such as in an amount of about 2% or less, and typically in an amount of about 0.1% or more, such as in an amount of about 0.3% or more.

[0082] In some embodiments, flame retardants suitable for use in conjunction with the cellulose ester plastics described herein may include, but are not limited to, silica, metal oxides, phosphates, catechol phosphates, resorcinol phosphates, borates, inorganic hydrates, aromatic polyhalides, and the like, and any combination thereof.

[0083] In some embodiments, antifungal and / or antibacterial agents suitable for use in conjunction with the cellulose ester plastics described herein can include, but are not limited to, polyene antifungal agents (e.g., natamycin, cytomycin, filipin, nystatin, amphotericin B, candesin, and hamycin), imidazole antifungal agents such as miconazole (available from WellSpring Pharmaceutical Corporation as ), ketoconazole (obtained from McNeil Consumer Healthcare for Commercially available), clotrimazole (available from Merck as and LOTRAMIN Commercially available from Bayer AG as Commercially available), econazole, omoconazole, bifonazole, butoconazole, fenticonazole, isoconazole, oxiconazole, sertaconazole (available from OrthoDematologics as commercially available), sulconazole, and tioconazole; triazole antifungals such as fluconazole, itraconazole, isavuconazole, ravuconazole, posaconazole, voriconazole, terconazole, and albaconazole), thiazole antifungals (e.g., abafungin), allylamine antifungals (e.g., terbinafine (available from Novartis Consumer Health, Inc. as commercially available), naftifine (available from Merz Pharmaceuticals as commercially available), and butenafine (available from Merck as LOTRAMIN commercially available), echinocandin antifungal agents (e.g., anidulafungin, caspofungin, and micafungin), polygonaldialdehyde, benzoic acid, ciclopirox olamine, tolnaftate (e.g., available from MDS Consumer Care, Inc. as commercially available), undecylenic acid, flucytosine, 5-fluorocytosine, griseofulvin, chloropropynyl iodine, octanoic acid, and any combination thereof.

[0084] In some embodiments, preservatives suitable for use in conjunction with the cellulose ester plastics described herein can include, but are not limited to, benzoates, parabens (eg, propyl 4-hydroxybenzoate series), and the like, and any combination thereof.

[0085] In some embodiments, pigments and dyes suitable for use in combination with the cellulose ester plastics described herein may include, but are not limited to, plant dyes, vegetable dyes, titanium dioxide, silicon dioxide, tartrazine, E102, phthalocyanine blue, phthalocyanine green, quinacridone, perylene tetracarboxylic acid diimide, dioxazine, perylene bis-azo pigments, anthraquinone pigments, carbon black, metal powders, iron oxide, ultramarine, calcium carbonate, kaolin, aluminum hydroxide, barium sulfate, zinc oxide, aluminum oxide, in liquid and / or granular form. Dyes (cationic dyes, available from Clariant Services) (e.g., Brilliant Yellow K-6G liquid, Yellow K-4GL liquid, Yellow K-GL liquid, Orange K-3GL liquid, Scarlet K-2GL liquid, Red K-3BN liquid, Blue K-5R liquid, Blue K-RL liquid, Turquoise K-RL liquid / granules, Brown K-BL liquid), Dye (an auxochrome, available from BASF) (eg, Yellow 3GL, Fastusol C Blue 74L), etc., any derivatives thereof, and any combination thereof.

[0086] In some embodiments, pigments and dyes suitable for use in conjunction with the cellulose ester plastics described herein can be food grade pigments and dyes. In some embodiments, examples of food grade pigments and dyes can include, but are not limited to, plant dyes, vegetable dyes, titanium dioxide, and the like, and any combination thereof.

[0087] In some embodiments, antioxidants can reduce oxidation and / or chemical degradation of the cellulose ester plastics described herein during storage, transportation, and / or implementation. In some embodiments, antioxidants suitable for use in conjunction with the cellulose ester plastics described herein can include, but are not limited to, anthocyanins, ascorbic acid, glutathione, lipoic acid, uric acid, resveratrol, flavonoids, carotenes (e.g., β-carotene), carotenoids, tocopherols (e.g., α-tocopherol, β-tocopherol, γ-tocopherol, and δ-tocopherol), tocotrienols, tocopherol esters (e.g., tocopherol acetate), panthenol, gallic acid, melatonin, secondary aromatic amines, benzofuranones, hindered phenols, polyphenols, hindered amines, organophosphorus compounds, thioesters, benzoates, lactones, hydroxylamines, butylated hydroxytoluene ("BHT"), butylated hydroxyanisole ("BHA"), hydroquinone, and the like, and any combination thereof.

[0088] In some embodiments, antioxidants suitable for use in combination with the cellulose ester plastics described herein can be food grade antioxidants. In some embodiments, examples of food grade antioxidants can include, but are not limited to, ascorbic acid, vitamin A, tocopherol, tocopherol esters, beta-carotene, flavonoids, BHT, BHA, hydroquinone, etc., and any combination thereof.

[0089] In one embodiment, the polymer composition contains an antioxidant comprising a phosphorus compound, particularly a phosphite. For example, in one embodiment, the antioxidant may be a diphosphite. For example, in one embodiment, the antioxidant is a pentaerythritol diphosphite, such as bis(2,4-dicumylphenyl)pentaerythritol diphosphite. The antioxidant may be present in the polymer composition typically in an amount less than about 2% by weight, such as in an amount less than about 1% by weight, such as in an amount less than about 0.5% by weight, such as in an amount less than about 0.3% by weight. The antioxidant may be present in the polymer composition typically in an amount greater than about 0.05% by weight, such as in an amount greater than about 0.08% by weight, such as in an amount greater than about 0.1% by weight, such as in an amount greater than about 0.13% by weight.

[0090] The polymer composition of the present disclosure can be formed into any suitable polymer article using any technique known in the art. For example, the polymer article can be formed from the polymer composition by extrusion, injection molding, blow molding, etc.

[0091] In one aspect, the polymer composition containing cellulose acetate can be formulated such that the polymer composition has properties very similar to petroleum-based polymers such as polypropylene. By matching the physical properties of petroleum-based polymers, the polymer compositions of the present disclosure are well suited to replace those polymers in many different end-use applications.

[0092] Polymeric articles that may be made according to the present disclosure include drinking straws, beverage holders, automotive parts, knobs, door handles, appliance parts, and the like.

[0093] For example, refer to Figure 1 , a drinking straw 10 that can be made according to the present disclosure is shown. In the past, drinking straws were conventionally made from petroleum-based polymers such as polypropylene. However, the cellulose acetate polymer composition of the present disclosure can be formulated to match the physical properties of polypropylene. Therefore, the drinking straw 10 can be produced according to the present disclosure and is fully biodegradable.

[0094] refer to Figure 2 , shows a cup or beverage holder 20 that can also be made according to the present disclosure. The cup 20 can be made, for example, using injection molding or by any suitable thermoforming process. Figure 7 As shown, the lid 22 of the cup 20 can also be made from the polymer composition of the present disclosure. The lid can include a pouring spout 24 for dispensing beverages from the cup 20. In addition to lids for beverage holders, the polymer composition of the present disclosure can be used to make lids for all different types of containers, including food containers, packaging containers, storage containers, etc.

[0095] In yet another embodiment, the polymer composition can be used to produce Figure 3 In addition to the beverage can 30, the polymer composition can also be used to produce Figure 4 A plastic bottle 40 is shown which may be used as a water bottle or other sports drink container.

[0096] refer to Figure 5 , showing an automobile interior. The automobile interior includes various automobile parts that can be manufactured according to the present disclosure. The polymer composition can be used, for example, to produce an automobile part 50, which includes at least a portion of an interior door handle. The polymer composition can also be used to produce parts on a steering column, such as automobile part 60. In general, the polymer composition can be used to mold any suitable decorative trim or border, such as trim 70. In addition, the polymer composition can be used to produce knobs or handles that can be used in the interior of a vehicle.

[0097] The polymer composition is also well suited for the production of tableware, such as forks, spoons and knives. Figure 6 , a disposable cutlery 80 is shown. The cutlery 80 includes a knife 82, a fork 84 and a spoon 86.

[0098] In yet another embodiment, the polymer composition can be used to produce Figure 8 Storage container 90 is shown. Storage container 90 can include a lid 94 that fits and engages the edge of a bottom 92. Bottom 92 can define an interior volume for containing items. Container 90 can be used to contain food items or dry items.

[0099] In still other embodiments, the polymer composition may be formulated to produce cardboard linings, eyeglass frames, screwdriver handles, or any other suitable part.

[0100] The cellulose ester composition of the present disclosure is also particularly well suited for the production of medical equipment, including all different types of medical devices. For example, the cellulose ester composition is well suited to replace other polymers used in the past, such as polycarbonate polymers. The cellulose ester composition of the present disclosure is not only biodegradable, but also has a unique "warm touch" when handled. Therefore, the composition is particularly well suited for the construction of the housing of medical equipment. For example, when held or gripped, the polymer composition retains heat and makes the device or instrument feel warmer than the device made of other materials in the past. This feeling is particularly soothing and comfortable for those who need medical assistance, and can also provide benefits for medical service providers. In one aspect, the cellulose ester composition for the production of the housing of medical equipment includes a cellulose ester polymer combined with a plasticizer (e.g., triacetin) and optionally another bio-based polymer. In addition, the composition can contain one or more colorants.

[0101] refer to Fig. 9 , for example, shows an inhaler 130 that can be made from a cellulose ester polymer composition. The inhaler 130 includes a housing 132 attached to a mouthpiece 134. Operably associated with the housing 132 is a plunger 136 for receiving a cartridge containing a composition to be inhaled. The composition may include a spray or a powder.

[0102] During use, the inhaler 130 administers a metered dose of a drug, such as an asthma drug, to the patient. The asthma drug may be suspended or dissolved in a propellant, or may be contained in a powder. When the patient activates the inhaler to inhale the drug, the valve opens, allowing the drug to leave the mouthpiece. According to the present disclosure, the housing 132, mouthpiece 134, and plunger 136 may all be made of a polymer composition as described above.

[0103] refer to Fig.10 , shows another medical product that can be manufactured according to the present disclosure. Fig.10 , a medical syringe 140 is shown. The medical syringe 140 includes a housing 142 operably associated with a plunger 144. The housing 142 can slide relative to the plunger 144. The medical syringe 140 can be spring-loaded. The medical syringe is used to inject a medication into a patient, typically into the thigh or buttocks. The medical syringe can be needle-free or can include a needle. When a needle is included, the needle tip is typically shielded within the housing before the injection. On the other hand, a needle-free syringe can include a cylinder of pressurized gas that pushes the medication through the skin without the use of a needle. According to the present disclosure, the housing 142 and / or the plunger 144 can be made of a polymer composition as described above.

[0104] like Fig.10 The medical syringe 140 shown can be used to inject insulin. Fig.12 , shows an insulin pump device 150 that can include a housing 156 also made from the polymer composition of the present disclosure. The insulin pump device 150 can include a pump in fluid communication with a tube 152 and a needle 154 for subcutaneously injecting insulin into a patient.

[0105] The polymer compositions of the present disclosure can also be used in all different types of laparoscopic devices. Laparoscopic surgery refers to a surgical procedure performed through an existing opening in the body or through one or more small incisions. Laparoscopic devices include different types of laparoscopes, needle holders, trocars, intestinal forceps, nasopharyngoscopes, etc.

[0106] refer to Fig.11, for example, a nasopharyngoscope 160 made according to the present disclosure is shown. The nasopharyngoscope 160 includes a small flexible plastic tube with optical fibers for viewing the airway. The nasopharyngoscope can be attached to a television camera to provide a permanent record of the examination. The nasopharyngoscope 160 includes a housing 162 made from the polymer composition of the present disclosure. The nasopharyngoscope 160 is used to examine the nose and throat. Under nasopharyngoscopy, the doctor can examine most of the inside of the nose, the Eustachian tube opening, the adenoids, the throat, and the vocal cords.

[0107] As described above, the molded article may be injection molded or thermoformed. When thermoforming, the polymer composition may first be formed into a film and then thermoformed into the article.

[0108] During thermoforming, the film substrate is heated and then molded into the desired three-dimensional shape. The substrate can be formed on a male or female mold. There are two main types of thermoforming, typically referred to as vacuum forming or pressure forming. Both types of thermoforming use heat and pressure to mold the film substrate into its final shape. During vacuum forming, the film substrate is placed on a mold and vacuum is used to mold it into a three-dimensional article. During pressure forming, pressure, optionally combined with vacuum force, is used to mold the film substrate into a shape.

[0109] There are various advantages to using thermoforming to produce three-dimensional articles. For example, thermoforming allows all different types of shapes to be produced with a quick turnaround time. Modifications to the design can also occur quickly and efficiently. Thermoforming is also cost-effective and can produce articles with an aesthetic appearance.

[0110] The temperature and pressure to which the foam substrate is subjected during the thermoforming process can vary depending on a variety of factors, including the thickness of the foam substrate and the type of product being formed. Typically, thermoforming can be performed at a temperature of about 75° to about 120°, such as about 75° to about 100°. However, higher temperatures may also be used. As described above, the foam substrate is also subjected to pressure and / or suction forces that press the foam substrate against the mold so that the foam substrate conforms to the shape of the mold. After molding, the three-dimensional article can be trimmed and / or polished as desired.

[0111] As noted above, one or more salt additives in combination with a cellulose ester polymer can significantly reduce the melt flow rate of the resulting polymer composition. In addition to improving the melt processing characteristics of the polymer composition, the inclusion of a salt additive can also increase tensile strength, increase modulus, and can also increase the deflection temperature of the composition. It is believed that the use of one or more salt additives in a polymer composition can also improve the appearance of molded articles made from the polymer composition.

[0112] In one aspect, the improvement in surface properties can be determined by a decrease in light intensity (L*). For example, a salt additive can be combined with a cellulose ester polymer such that the resulting composition has an L* value that is less than the L* value of the same composition without the salt additive and having the same amount of cellulose ester polymer. For example, the L* value can be reduced by greater than about 0.1%, such as greater than about 0.3%, such as greater than about 0.5%, such as greater than about 0.8%, such as greater than about 1%.

[0113] As used herein, CIELab color values ​​L*, a* and b* are measured in color space according to the International Commission on Illumination specified. The L*a*b* colorimetric system was standardized by the International Commission on Illumination (CIE) in 1976. The CIELab L* value used herein to define the darkness / brightness of a polymer composition is the unit of color measurement in the above-mentioned CIELab system. Color can be matched according to CIELab. In the L*a*b* colorimetric system, L* refers to the brightness represented by a numerical value.

[0114] The molded article manufactured according to the present disclosure can also have excellent transparency characteristics.For example, the polymer composition of the present disclosure can show low haze characteristics.For example, the polymer composition shows less than about 50%, such as less than about 35%, such as less than about 25%, such as less than about 20%, such as less than about 15%, such as less than about 10%, such as less than about 8%, such as less than about 5%, such as less than about 3%, such as less than about 2%, such as less than about 1%, such as less than about 0.8%, such as less than about 0.5%, such as less than about 0.4%, such as less than about 0.3%, such as less than about 0.2% haze. Generally, the haze of the polymer article manufactured according to the present disclosure can be measured according to ASTM test D1003 (2013). Any acceptable instrument can be used to measure haze according to ASTM test, including such as BYK Gardner Haze-Gard 4725 instrument. Haze can be measured on a test substrate, on a film manufactured according to the present disclosure, or on a final thermoformed article. The test substrate may have any suitable thickness, such as 1 mm, 2 mm, 3 mm, or 4 mm.

[0115] The present disclosure may be better understood with reference to the following examples. Instance Number 1

[0116] Cellulose ester polymers were combined with plasticizers and varying amounts of calcium acetate according to the present disclosure and tested for melt flow rate. Each sample contained a cellulose ester polymer having an acetyl value of about 52.6 and an intrinsic viscosity of 1.65 dL / g. Each sample contained triacetin as a plasticizer in an amount of 24% by weight. The following samples were formulated: Sample No. Amount of calcium acetate (ppm) 1 0 2 200 3 600

[0117] The above composition was extruded into pellets and then tested for melt flow rate. The temperature during extrusion was changed. The melt flow rate was tested at 210°C and under a load of 2.16 kg. The following results were obtained:

[0118] As shown above, the addition of a small amount of a salt additive to facilitate melt processing of the composition significantly and unexpectedly reduces the melt flow index. Instance number 2

[0119] The cellulose ester polymer described in Example No. 1 in the form of flakes was washed with water, calcium acetate solution, and magnesium acetate solution. The flakes were then subjected to thermogravimetric analysis (TGA) using ISO test 11358. The following results were obtained:

[0120] The cellulose ester polymer washed with the salt additive according to the present disclosure exhibits retained molecular weight or increased molecular weight even after TGA testing at 220°C for 30 minutes.

[0121] The above samples were also subjected to gel permeation chromatography (GPC) after heating to 220°C for 30 minutes. The following results were obtained:

[0122] Without departing from the spirit and scope of the present invention (which is more particularly described in the appended claims), those of ordinary skill in the art may practice these and other modifications and variations of the present invention. In addition, it should be understood that aspects of the various embodiments may be interchangeable in whole or in part. In addition, those of ordinary skill in the art will appreciate that the foregoing description is by way of example only and is not intended to limit the present invention (which is further described in the appended claims).

Claims

1. A polymer composition, comprising: a cellulose ester polymer present in the composition in an amount greater than about 40% by weight, the cellulose ester polymer having an acetyl value of from about 48% to about 56%; Plasticizers; and A salt additive is present in an amount sufficient to reduce the melt flow rate of the polymer composition by greater than about 20% compared to the same polymer composition without the salt additive.

2. The polymer composition according to claim 1, wherein The salt additive contributes cations to the polymer composition.

3. The polymer composition according to claim 1, wherein The salt additive is present in the polymer composition in an amount sufficient to reduce the melt flow rate of the composition by greater than about 30%, such as greater than about 40%, such as greater than about 50%, such as greater than about 60%, such as greater than about 70%, such as greater than about 80%.

4. The polymer composition according to claim 1, wherein When tested at 210°C and under a load of 2.16 kg, the polymer composition has a melt flow rate of less than about 20 g / 10 min, such as less than about 18 g / 10 min, such as less than about 15 g / 10 min, such as less than about 12 g / 10 min, such as less than about 10 g / 10 min, such as less than about 8 g / 10 min.

5. A polymer composition as claimed in any one of the preceding claims, wherein The salt additive causes ionic crosslinking of the cellulose ester polymer.

6. A polymer composition as claimed in any one of the preceding claims, wherein The salt additive is present in the polymer composition in an amount from about 1 ppm to about 10,000 ppm, such as from about 10 ppm to about 1,200 ppm, such as from about 10 ppm to about 800 ppm.

7. A polymer composition as claimed in any one of the preceding claims, wherein The salt additive includes a metal salt.

8. A polymer composition as claimed in any one of the preceding claims, wherein The salt additive includes salts having multivalent cations, such as salts having +2 or +3 cations.

9. A polymer composition as claimed in any one of the preceding claims, wherein The salt additive includes calcium salt, magnesium salt, iron salt, aluminum salt, zinc salt, cobalt salt, manganese salt, or a mixture thereof.

10. A polymer composition as claimed in any one of the preceding claims, wherein The salt additive includes calcium acetate, magnesium acetate, calcium hydroxide, ferrous acetate, ferric acetate, zinc acetate, cobalt acetate, manganese acetate, magnesium hydroxide, calcium sulfate, calcium bicarbonate, calcium bromide, calcium chloride, calcium nitrate, calcium perchlorate, calcium propionate, calcium benzoate, magnesium bromide, magnesium chlorate, magnesium nitrate, magnesium perchlorate, magnesium sulfate, magnesium thiosulfate, calcium citrate, calcium gluconate, calcium lactate, zinc acetate, cobalt acetate, manganese acetate, lime, or a mixture thereof.

11. A polymer composition as claimed in any one of the preceding claims, wherein The cellulose ester polymer has an acetyl value greater than 50% and less than 54%.

12. A polymer composition as claimed in any one of the preceding claims, wherein The salt additive is present in the composition in an amount sufficient to reduce the L* value of an article formed from the polymer composition.

13. A polymer composition as claimed in any one of the preceding claims, wherein The cellulose ester polymer is present in the polymer composition in an amount of about 55% by weight to about 95% by weight, and the plasticizer is present in an amount of about 5% by weight to about 40% by weight.

14. A polymer composition as claimed in any one of the preceding claims, wherein The plasticizer includes tris(chloroisopropyl) phosphate, tris(2-chloro-1-methylethyl) phosphate, glycerol, monoacetin, triethyl citrate, acetyl triethyl citrate, phthalates, adipic acid esters, polyethylene glycol, triacetin, diacetin, trimethyl phosphate, triethyl phosphate, tributyl phosphate, triphenyl phosphate, o-acetyl tributyl citrate, dibutyl tartrate, ethyl o-benzoyl benzoate, n-ethyl toluenesulfonamide, o-tolyl p-toluenesulfonate, aromatic diols, substituted aromatic diols, aromatic ethers, tripropionin, glyceryl tribenzoate, glyceryl esters, glycerol tribenzoate, glycerol acetate benzoate, polyethylene glycol, polyethylene glycol esters, polyethylene glycol diesters, di-2-ethylhexyl polyethylene glycol esters, glycerol esters, diethylene glycol, polypropylene glycol, polyglycol diglycidyl ether, dimethyl sulfoxide, N-methylpyrrolidone, Propylene carbonate, C1-C20 dicarboxylic acid esters, dibutyl maleate, dioctyl maleate, resorcinol monoacetate, catechol, catechol esters, phenols, epoxidized soybean oil, castor oil, linseed oil, epoxidized linseed oil, difunctional glycidyl ether based on polyethylene glycol, alkyl lactones, 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, glyceryl tribenzoate, neopentyl dibenzoate, triethylene glycol dibenzoate, trimethylolethane tribenzoate, butylated hydroxytoluene, butylated hydroxyanisole, sorbitol, xylitol, ethylenediamine, piperidine, piperazine, hexamethylenediamine, triazine, triazole, pyrrole, polycaprolactone diol and mixtures thereof.

15. The polymer composition according to any one of claims 1 to 13, wherein The plasticizer includes triacetin, polyethylene glycol, or a mixture thereof.

16. A polymer composition as claimed in any one of the preceding claims, wherein Cellulose acetate consists essentially of cellulose diacetate.

17. An article made from the polymer composition as claimed in any one of the preceding claims.

18. The article of claim 17, wherein: The articles have been formed by injection moulding or extrusion.

19. The article of claim 17, wherein: The article is a beverage holder, a drinking straw, a hot beverage can, a fork, a knife, a spoon, a packaging material, a container, a lid, or an automotive interior part.

20. A polymer composition comprising: a cellulose ester polymer present in the composition in an amount greater than about 40% by weight, the cellulose ester polymer having an acetyl value of from about 48% to about 56%; a plasticizer, the plasticizer being present in the polymer composition in an amount of about 12% by weight to about 35% by weight; and A salt additive that contributes cations to the polymer composition, and wherein the polymer composition has a melt flow index of less than 20 g / 10 min when tested at 210° C. and under a load of 2.16 kg.

21. The polymer composition of claim 20, wherein The cellulose ester polymer is present in the polymer composition in an amount of about 60% to about 88% by weight.

22. The polymer composition according to claim 20 or 21, wherein The polymer composition has a melt flow rate of less than about 15 g / 10 min, such as less than about 10 g / 10 min.

23. A polymer composition comprising: a cellulose ester polymer present in the composition in an amount greater than about 40% by weight; Plasticizers; and A salt additive that contributes cations to the polymer composition, the salt additive being present in an amount sufficient to reduce the melt flow rate of the polymer composition by greater than about 20% compared to the same polymer composition without the salt additive.

24. A polymer composition comprising: a cellulose ester polymer present in the composition in an amount greater than about 40% by weight, the cellulose ester polymer having an acetyl value of from about 48% to about 56%; Plasticizers; and Wherein the composition has a melt flow rate of less than about 20 g / 10 min, such as less than about 18 g / 10 min, such as less than about 15 g / 10 min, such as less than about 12 g / 10 min, such as less than about 10 g / 10 min, such as less than about 8 g / 10 min, when tested at 210°C and under a load of 2.16 kg.

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