Polymer compositions comprising active carbon for formaldehyde sorption

Abstract

To provide polymer compositions comprising activated carbon and method of making the polymer compositions that are used for sorption of formaldehyde from air, gas or liquids.SOLUTION: Provided is a process for making a polymer composition for formaldehyde sorption, the process comprising the steps of: (a) providing a base polymer; (b) adding an activated carbon to the base polymer; and (c) optionally, adding a channeling agent to the base polymer; wherein the formaldehyde is contained in air, a gas or a liquid.SELECTED DRAWING: Figure 6

Description

[Technical field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to U.S. Provisional Patent Application No. 62 / 835,068, entitled “ENTRAINED POLYMERS AS FORMALDEHYDE SCAVENGER,” filed April 17, 2019, the entire disclosure of which is incorporated herein by reference in its entirety.

[0002] The present invention relates to a polymeric material used to adsorb or absorb formaldehyde from gases or liquids. The polymeric composition includes activated carbon as an activator. The polymeric composition is incorporated into various applications, such as packaging materials. In certain embodiments, the polymeric composition of the present invention reduces the cross-linking effect caused by the presence of formaldehyde in gelatin. [Background technology]

[0003] Formaldehyde, also known as methanal or formic acid, is a naturally occurring organic compound with the formula CHO. It is the simplest of the aldehydes. Formaldehyde is an important precursor to many materials and chemical compounds. It is a colorless, strong-odored gas used in the creation of building materials and many household products. It is used in the manufacture of plastic resins; pressed wood products such as particleboard, plywood, and fiberboard; glues and adhesives; permanent-press fabrics in the textile industry; coatings for paper products; and certain insulation materials. Formaldehyde is ubiquitous in the environment, present as an impurity or decomposition product, and is produced from both natural and man-made sources.

[0004] In the area of ​​packaging products, in some cases, free formaldehyde is retained in fully cured composites, laminates, and coatings. Gaseous formaldehyde can be released slowly from cured compositions at room temperature or slightly elevated temperatures in the presence of water or under high humidity conditions. Because formaldehyde is volatile and remains gaseous at ambient temperature and pressure, it leaks into the air during the manufacture of polymers, resins, and other materials, and products prepared therefrom. Release of gaseous formaldehyde can also occur when the finished product is in place or in use.

[0005] Formaldehyde also occurs in many animal and plant species as a product of their natural and normal metabolism. Ingestion of small amounts of formaldehyde by humans is unlikely to cause acute effects, but ingestion of larger amounts can generally cause severe abdominal pain, vomiting, coma, kidney damage, and may lead to death. The general public can also be exposed to formaldehyde through inhalation of the atmospheric gas. The main health concern of formaldehyde is its ability to cause cancer. The World Health Organization's International Agency for Research on Cancer has classified formaldehyde as "carcinogenic to humans," given the existence of sufficient evidence for the cause of nasopharyngeal carcinoma in humans, a causal association with leukemia, and strong potential evidence of occupational exposure.

[0006] As a product of normal metabolism, formaldehyde has been reported to be naturally present in many common foods, including fruits and vegetables, meat, fish, shellfish, and dried mushrooms. In some seafood, formaldehyde is a natural decomposition product of a chemical known as trimethylamine oxide (TMAO) present in the organism's body. Trimethylamine oxide breaks down into equal parts formaldehyde and dimethylamine after the animal's death. Levels of formaldehyde can accumulate in certain marine fish and shellfish during frozen storage and pose a potential health risk to humans upon consumption of these foods.

[0007] Regarding the presence of formaldehyde in the atmosphere, aqueous solutions or liquid absorbents such as ammonium bicarbonate, or solid absorbents such as activated carbon have been used to absorb gaseous formaldehyde from the atmosphere. Water and liquid absorbents in scrub towers have been used in manufacturing facilities where large volumes of air are recirculated. It has further been found that gaseous formaldehyde can be removed from the atmosphere under ambient conditions by contacting it with a solid form composition prepared by coating a solid substrate with a solid absorbent such as a polyvalent water-soluble polymer and water and an oxidizing agent, or by impregnating a porous or fibrous solid substrate. Such oxidizing agents, such as metal peroxides and potassium permanganate, are effective in converting formaldehyde to formic acid. However, they are nonselective and rapidly lose their reactivity by indiscriminate oxidation of other contaminants and pollutants with reducing properties, such as mercaptans, hydrogen sulfide, and carbon monoxide. Removal of formaldehyde has also been attempted by oxidation of the formaldehyde by passing air through alumina or clay pellets impregnated with alkaline earth metal peroxides or potassium permanganate, however, these processes are expensive and impractical for use in small areas or in packaging used with products that emit formaldehyde.

[0008] In the pharmaceutical industry, gelatin capsules have been used for a long time to encapsulate various pharmaceutical dosage forms. The integrity and stability of gelatin capsules are important to maintain the safety and efficacy of the pharmaceutical product held in the capsule. However, gelatin-containing products such as gelatin capsules are vulnerable to cross-linking. "Cross-linking" refers to the process in which bonds are formed that connect one polymer chain to another. These bonds can take the form of covalent or ionic bonds and usually cause changes in the physical properties of the polymer. Thus, cross-linking can slow or prevent drug release from gelatin capsules, resulting in highly variable and off-specification dissolution results for drug products. Formaldehyde is an agent known to cause cross-linking of gelatin. Hakata T., Sato H., Watanabe Y., Matsumoto M. 1994, "Effect of Formaldehyde on the Physiochemical Properties of Soft Gelatin Capsule Shells", Chem.Pharm.Bull.42(5)1138-1142. Thus, there is a need for compositions or methods that adsorb or absorb formaldehyde in pharmaceutical packaging and encapsulation to maintain the safety, efficacy, and shelf life of pharmaceutical products.

[0009] Activated carbon is known to adsorb water and many volatile organic compounds, including formaldehyde and formic acid. It is taught that solid absorbents such as activated carbon are effective at removing formaldehyde gas at normal temperatures, but lose efficiency when temperature or humidity levels increase. For example, in hot and humid conditions where formaldehyde vapor is likely to be released, the absorption capacity of activated carbon is typically reduced, and formaldehyde may desorb and be released into the surrounding air. There is a need for a composition having activated carbon that is effective at capturing formaldehyde and effectively retaining it within a closed environment, such as a packaging material or container.

[0010] Although many technologies have been developed for the removal of formaldehyde in industrial processes, food packaging, and pharmaceutical packaging, there continues to be a need for more effective and safer products. Summary of the Invention

[0011] Provided herein are polymer compositions and methods of making the polymer compositions for formaldehyde sorption from air, gas, or liquid, a process comprising providing a base polymer, adding activated carbon to the base polymer, and optionally adding a channeling agent to the base polymer, the process further comprising activating the activated carbon by contacting the polymer composition with a liquid or vapor.

[0012] The polymer composition is formed by extrusion, injection molding, blow molding, vacuum forming, or hot melt extrusion. The polymer composition can be formed into granules, pellets, films, sheets, disks, covers, plugs, caps, lids, inserts, stoppers, gaskets, seals, washers, liners, rings, containers, or packaging materials. The polymer composition can further be incorporated into a packaging material selected from plastic, paper, glass, metal, ceramic, synthetic resin, or combinations thereof.

[0013] Certain embodiments are disclosed in which the polymer composition comprises polypropylene as the base polymer, tris(hydroxymethyl)aminomethane as the activated carbon, and optionally polyethylene glycol as the channeling agent.

[0014] In an alternative embodiment, the polymer composition is in the form of a film and is provided in a blister pack or gel pack. [Brief description of the drawings]

[0015] The following detailed description of the technology disclosed herein will be better understood when read in conjunction with the accompanying drawings. For the purpose of illustrating the technology disclosed herein, there are shown in the drawings various exemplary embodiments. It is to be understood, however, that the technology disclosed herein is not limited to the detailed arrangements and instrumentalities shown. The present invention will be described in conjunction with the following drawings, in which like reference numerals refer to like elements. [Figure 1] FIG. 2 is a perspective view of a plug formed with an entrained polymer, according to an optional embodiment of the present invention. [Diagram 2] FIG. 2 is a cross-sectional view taken along line 2-2 of FIG. [Diagram 3] 3 is a cross-sectional view similar to FIG. 2 showing a plug formed with another embodiment of an entrained polymer according to the invention, showing a smaller channel than the embodiment of FIG. 1. [Figure 4] FIG. 4 is a close-up schematic diagram of FIG. 3 showing an entrained polymer according to the present invention, with activated carbon as the activator, and with formaldehyde passing through and being absorbed or adsorbed within the polymer composition. [Diagram 5] FIG. 2 is a cross-sectional schematic diagram of another embodiment of the entrained polymer of the present invention showing multiple layers of the entrained film. [Figure 6] 1 is a graph showing formaldehyde uptake of entrained polymeric material according to any embodiment of the present invention according to Example 1. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] Although the systems, devices, and methods are described herein by examples and embodiments, those skilled in the art will recognize that the disclosed technology is not limited to the described embodiments or drawings. Rather, the disclosed technology encompasses all modifications, equivalents, and alternatives that fall within the spirit and scope of the appended claims. Features of any one embodiment disclosed herein may be omitted or incorporated in other embodiments.

[0017] definition Any headings used herein are for organizational purposes only and are not meant to limit the scope of the specification or claims. As used herein, the word "may" is used in its permissive (i.e., having the possibility) sense rather than its mandatory (i.e., must) sense. Unless specifically stated herein, the terms "a," "an," and "the" are not limited to one element, but should instead be read to mean "at least one." Terms include the above words, derivatives thereof, and words of similar meaning.

[0018] As used herein, the term "active" is defined as being capable of acting on, interacting with, or reacting with formaldehyde according to the present invention, which acting or interacting may include absorbing and / or adsorbing (and / or releasing) formaldehyde.

[0019] As used herein, the term "active agent" is defined as a material that (1) is incompatible with the base polymer and does not melt when mixed and heated with the base polymer and channeling agent, i.e., has a melting point higher than the melting point for either the base polymer or the channeling agent, and (2) acts on, interacts with, or reacts with a selected material. Specifically, as used herein, the term "active agent" includes materials that absorb or adsorb a selected material, specifically, as used herein, that absorb or adsorb formaldehyde.

[0020] As used herein, the term "activated carbon" refers to a collective name for a group of porous carbons produced by the treatment of char with oxidizing gases or by carbonization of carbonaceous materials impregnated with dehydration chemicals. The term "activated charcoal" is also commonly used. The term "activated" is colloquially used interchangeably with "active." Further chemical treatment or processing of the carbon often enhances the adsorptive properties of activated carbon, and it is referred to as "impregnated" activated carbon. The term "activated carbon" is used herein to refer to both non-impregnated and impregnated activated carbon.

[0021] As used herein, the term "base polymer" is a polymer that optionally has a gas transmission rate that is significantly lower than, lower than, or substantially equivalent to that of the selected material's gas transmission rate of the channeling agent. By way of example, in an embodiment in which the selected material is moisture and the active agent is a water-absorbing or formaldehyde-adsorbing desiccant, such transmission rate is the water vapor transmission rate. The primary function of the base polymer is to provide structure and enable the function of the activated carbon.

[0022] As used herein, the term "channeling agent" is defined as a material that is incompatible with a base polymer and has an affinity to transport a gas phase substance at a faster rate than the base polymer alone. Optionally, the channeling agent is capable of forming channels through the base polymer when formed by mixing the channeling agent with the base polymer. Optionally, such channels are capable of permeating a selected material through the entrained polymer at a faster rate than the base polymer alone.

[0023] As used herein, the term "channel" or "interconnected channels" is defined as passages formed by a channeling agent that run through the base polymer and can interconnect with one another.

[0024] As used herein, the terms "container" or "packaging" and "packaging" may be used interchangeably herein to refer to a structure that holds or contains a commodity or product. Optionally, the packaging may include a container in which the product is stored. Non-limiting examples of containers, packaging, and packaging include boxes, trays, cartons, bottles, vessels, pouches, blister packs, and bags. The packaging or container may be closed, covered, and / or sealed using a variety of mechanisms including, for example, covers, lids, lid sealants, adhesives, and / or heat seals. The packaging or container may be composed or constructed of a variety of materials such as plastic, metal, resin, glass, wood, combinations thereof, and any other material. In one optional embodiment, the packaging or container is made of a rigid or semi-rigid polymer, optionally polypropylene or polyethylene, preferably with sufficient rigidity to retain its shape under gravity.

[0025] As used herein, the term "entrained polymer" is defined as a monolithic material formed of at least a base polymer and an active agent entrained or dispersed throughout, and optionally a channeling agent. Entrained polymers therefore include two-phase polymers (without channeling agent) and three-phase polymers (with channeling agent). Entrained polymers are described, for example, in U.S. Pat. Nos. 5,911,937, 6,080,350, 6,124,006, 6,130,263, 6,194,079, 6,214,255, 6,486,231, 7,005,459, and U.S. Patent Publication No. 2016 / 0039955, each of which is incorporated herein by reference in its entirety.

[0026] As used herein, the terms "monolithic," "monolithic structure," or "monolithic composition" are defined as a composition or material that does not consist of two or more separate macroscopic layers or portions. Thus, a "monolithic composition" is not itself a multilayer composite, although a monolithic composition may form a layer of such a composite.

[0027] As used herein, the term "phase" is defined as a part or component of a monolithic structure or composition that is uniformly distributed throughout so as to give the structure or composition its monolithic character.

[0028] As used herein, the term "sorption" refers to both "absorption" and "adsorption," which may be used interchangeably herein. "Adsorption" refers to the attachment of atoms, ions, or molecules from a gas, liquid, or dissolved solid to a surface. This process creates a film of the adsorbate on the surface of the adsorbent. "Absorption" is the process by which a fluid (the absorbent) is dissolved by or permeated by a liquid or solid (the absorbent), respectively. Adsorption is a surface phenomenon, while absorption involves the entire volume of the material. The term "sorption" encompasses both processes.

[0029] As used herein, the term "three-phase" is defined as a monolithic composition or structure that includes three or more phases. An example of a three-phase composition according to an exemplary embodiment is an entrained polymer formed by a base polymer, activated carbon, and a channeling agent. Optionally, the three-phase composition or structure may include additional phases, such as a colorant or additional desiccant.

[0030] EMBODIMENTS OF THE PRESENT DISCLOSURE The present invention utilizes activated carbon as an activator incorporated into a base polymer to function as a desiccant to remove or capture formaldehyde. The base polymer may optionally include one or more other additives. Optionally, the base polymer and the additives are compatible with each other. Activated carbon functions to absorb or adsorb formaldehyde due to the high surface area within the structure of activated carbon. Further chemical treatment may enhance the adsorption properties of activated carbon. The polymer compositions described herein may be used alone or in mixtures with other solid absorbents or desiccants.

[0031] Without being bound by the mechanism of action, the activated carbon entrained polymeric compositions of the present invention function to remove, reduce, capture, control, or modify the level of formaldehyde in the environment. In any embodiment, a material made from the polymeric composition herein is placed in a sealed environment, such as a sealed chamber, packaging, or container, to measurably achieve formaldehyde capture within such sealed or enclosed environment.

[0032] Activated carbon is a form of carbon or carbonaceous material (char) that is treated during or after carbonization to increase its adsorption properties. It is physically or chemically treated to generate microcracks that greatly increase the adsorption surface area. The large surface area and charge effectively adsorb a wide range of polar compounds. The char is engineered to have small, low-volume pores that increase the surface area of ​​the carbon particle available for adsorption or chemical reaction. Due to its high degree of microporosity, one gram of activated carbon can adsorb up to 3,000 m of gas as determined by gas adsorption. 2 (32,000ft 2 ), the activation level sufficient for useful sorption can only be obtained from that high surface area. Activated carbon is usually derived from charcoal, but can also be derived from coal, coconut shells, wood, resins, and petroleum.

[0033] Activated carbon as used herein may be impregnated or non-impregnated. Impregnated activated carbon is a carbonaceous adsorbent having chemicals finely distributed on its inner surface. Impregnation optimizes the existing properties of the activated carbon and results in a synergistic effect between the chemicals and the carbon. Numerous impregnated carbons are known in the industry and may be used in the inventive polymer compositions and methods herein. An optional embodiment of the impregnated carbon herein is tris(hydroxymethyl)aminomethane (Tris or TRIS) impregnated carbon. Optionally, the inventive polymer composition contains 1-30% Tris impregnated activated carbon and 70-99% high density polyethylene polymer (HDPE).

[0034] The activated carbon used in the polymer compositions of the present invention can be of various particle sizes. Activated carbon can be prepared from sources such as coal, coke, charcoal, coconut shells, wood, resins, petroleum residues, or from about 100 ml of activated carbon. 2 / g~2,000m 2 / g, typically 500-1500m 2 The activated carbon may be prepared by other known processes that produce activated carbon having a specific surface area of ​​1000 nm to 1000 nm / g. The activated carbon activator may be provided in any form, such as a powder, crushed, granular, pelleted, spherical, cylindrical, fibrous, or honeycomb form.

[0035] Activated carbon useful herein may be prepared by any of a variety of methods commonly known in the industry, dating back to U.S. Patent No. 1,497,543 to Newcomb Chaney in 1919. In accordance with the invention herein, any form of activated carbon manufactured or purchased from a valid supplier may be utilized for the inventive polymer compositions and methods herein.

[0036] The polymer composition of the present invention can be prepared by common manufacturing processes such as extrusion, injection molding, blow molding, and hot melt, and the activated carbon activator is added to the base polymer during the manufacturing process, and the materials are combined and generally mixed or blended to some degree with each other. The resulting combination of the base polymer mixed with the activated carbon becomes the entrained polymer composition. According to the present invention, the activated carbon does not need to be uniformly distributed throughout the base polymer to impart formaldehyde-scavenging properties to the entrained polymer composition. In any embodiment, the activated carbon can be uniformly or essentially uniformly distributed within the base polymer so that the entrained polymer composition is homogenous or essentially homogenous.

[0037] Referring now in detail to the figures, like reference numerals refer to like parts throughout. Shown in Figures 1-5 are exemplary entrained polymers 10 that may be used in conjunction with embodiments of the present invention. The entrained polymers 10 each include a base polymer 25, a channeling agent 35, and an active agent that is activated carbon 30. As shown, the channeling agent 35 forms interconnecting channels 45 through the base polymer 10. At least a portion of the activated carbon 30 is contained within these channels 45 such that the channels 45 communicate between the activated carbon 30 and the exterior of the entrained polymer 10 through channel openings 48 formed in the outer surface of the entrained polymer 25. While a channeling agent, such as 35, is preferred, in any embodiment, the present invention also includes entrained polymers that do not include a channeling agent.

[0038] Suitable base polymers include thermoplastic polymers, e.g., polyolefins such as polypropylene and polyethylene, polyisoprene, polyhydroxyalkanoates (PHAs), polylactique acid (PLA), polybutylene succinate (PBS), polybutadiene, polybutene, polysiloxanes, polycarbonates, polyamides, ethylene-vinyl acetate copolymers, ethylene-methacrylate copolymers, poly(vinyl chloride), polyvinylpyrrolidone, polystyrene, polyesters, polyanhydrides, polyacrylianitriles, polysulfones, polyacrylates, acrylics, polyurethanes, and polyacetals, or copolymers or combinations thereof.

[0039] Suitable channeling agents include polyglycols such as polyethylene glycol (PEG), ethylene-vinyl alcohol (EVOH), polyvinyl alcohol (PVOH), glycerin polyamines, polyurethanes, and polycarboxylic acids including polyacrylic acid or polymethacrylic acid. Alternatively, the channeling agent 35 can be a water insoluble polymer such as propylene oxide polymerisate-monobutyl ether, such as polyglykol B01 / 240 manufactured by Clariant Specialty Chemicals. In other embodiments, the channeling agent can be propylene oxide polymerisate-monobutyl ether, such as polyglykol B01 / 20 manufactured by Clariant Specialty Chemicals, propylene oxide polymerisate, such as polyglykol D01 / 240 manufactured by Clariant Specialty Chemicals, ethylene vinyl acetate, nylon 6, nylon 66, or any combination of the above.

[0040] Generally, it is believed that the higher the concentration of active agent in the polymer composition, the greater the sorption performance of the final composition. However, too high a concentration of activated carbon can cause the entrained polymer to become increasingly brittle, making it more difficult to either thermoform, extrude, injection mold, or hot melt the molten mixture of active agent, base polymer, and channeling agent.

[0041] In any embodiment of the present invention, the loading level of activated carbon in the entrained polymer composition may range from 10% to 80% by weight, preferably 20% to 70% by weight, more preferably 30% to 60% by weight, and even more preferably 25% to 55% by weight, based on the total weight of the entrained polymer. Optionally, the base polymer may range from 10% to 90% by weight, preferably 20% to 80% by weight of the total composition. If an optional channeling agent is used, the channeling agent may be provided in the range of 1% to 15% by weight, optionally 2% to 10% by weight, and preferably about 5% by weight.

[0042] 1, there is shown an insert 20 constructed from the entrained polymer of the present invention. The insert 20 is in the form of a plug 55 that can be placed within a packaging material or chamber of a container to capture formaldehyde from formaldehyde-producing bodies disposed within the container.

[0043] Referring to Figure 2, there is shown a cross-sectional view of a plug 55 constructed from an entrained polymer 10, including a base polymer 25 homogeneously blended with activated carbon 30 and an optional channeling agent 35. In the view of Figure 2, the entrained polymer has been solidified such that interconnecting channels 45 are formed throughout the entrained polymer 10, establishing passageways throughout the solidified plug 55. As can be seen from both Figures 1 and 2, the passageways terminate at channel openings 48 on the exterior surface of the plug 55, creating a larger surface area for the activated carbon to capture formaldehyde from the environment surrounding the polymer composition.

[0044] FIG. 3 shows an embodiment of a plug 55 similar in construction and composition to the plug 55 of FIG. 2, with the interconnecting channels 45 being much finer compared to those of FIG. 2. This may be the result of using a dimerizing agent (i.e., a plasticizer) along with the channeling agent 35. The dimerizing agent may improve compatibility between the base polymer 25 and the channeling agent 35. This improved compatibility may be aided by a reduced viscosity of the blend, thereby facilitating a more complete blending of the base polymer 25 and the channeling agent 35, which may be difficult to mix into a homogenous solution under normal conditions. When the entrained polymer 10 with the added dimerizing agent solidifies, the interconnecting channels 45 formed throughout have greater dispersion and less porosity, thereby establishing a higher density of interconnecting channels throughout the plug 55.

[0045] FIG. 4 shows a further embodiment of an entrained polymer 10 using activated carbon as the activator 30, with the arrows indicating the path of formaldehyde gas, or optionally a liquid containing formaldehyde, from the exterior of the entrained polymer 10, through channels 45 to the particles of activated carbon 30, which upon contact function to absorb or adsorb formaldehyde within the channels.

[0046] The interconnecting channels 45, such as those disclosed herein, facilitate the permeation of formaldehyde throughout the base polymer 25, which would otherwise generally resist the penetration of formaldehyde gas and thus act as a barrier thereto. Thus, the base polymer 25 itself acts as a barrier material within which the active agent 30 can be entrained. The interconnecting channels 45 formed with the channeling agent 35 provide a path for formaldehyde to travel through the entraining polymer 10. In the absence of these interconnecting channels 45, it is believed that a relatively small amount of the desired material would permeate through the base polymer 25 to or from the active agent 30. The channels further allow a larger surface area of ​​the activated carbon to come into contact with the formaldehyde. Thus, the formaldehyde permeates through the activated carbon 30 and is absorbed or adsorbed by the activated carbon 30 in a much larger amount than material not entrained with the activated carbon. Thus, in one aspect, activated carbon as a sorbent and an entraining polymer, including a base polymer, are used in embodiments of the present invention. In another aspect, activated carbon as a sorbent, a base polymer, and an entrained polymer including a channeling agent may be used in embodiments of the present invention. However, in certain cases, especially when the selected base polymer does not have significant barrier properties and / or is provided in a thin film, the performance of the entrained polymer may be suitable for a particular use without the channeling agent.

[0047] Optionally, in any embodiment, the loading level of activated carbon is in the range of 10% to 80% by weight, optionally 20% to 70% by weight, optionally 30% to 60% by weight, optionally 40% to 50% by weight, optionally 45% to 65% by weight, optionally 45% to 60% by weight, optionally 45% to 55% by weight, optionally 50% to 70% by weight, optionally 50% to 60% by weight, optionally 55% to 65% by weight, optionally 55% to 60% by weight, based on the total weight of the entrained polymer composition.

[0048] Optionally, in any embodiment, the loading level of base polymer is from 10% to 80%, optionally from 20% to 70%, optionally from 30% to 60%, optionally from 40% to 50%, optionally from 45% to 65%, optionally from 45% to 60%, optionally from 45% to 55%, optionally from 50% to 70%, optionally from 50% to 60%, optionally from 55% to 65%, optionally from 55% to 60%, 15% to 75%, optionally from 25% to 70%, by weight of the entrained polymer composition. %, optionally in the range of 35% to 60% by weight, optionally 45% to 55% by weight, optionally 20% to 50% by weight, optionally 20% to 40% by weight, optionally 20% to 35% by weight, optionally 25% to 60% by weight, optionally 25% to 50% by weight, optionally 25% to 40% by weight, optionally 25% to 30% by weight, optionally 30% to 60% by weight, optionally 30% to 50% by weight, optionally 30% to 45% by weight, optionally 40% to 60% by weight, optionally 40% to 50% by weight.

[0049] Optionally, in any embodiment, the loading level of any channeling agent is in the range of 1 wt% to 25 wt%, optionally 2 wt% to 15 wt%, optionally 5 wt% to 20 wt%, optionally 5 wt% to 15 wt%, optionally 5 wt% to 10 wt%, optionally 8 wt% to 15 wt%, optionally 8 wt% to 10 wt%, optionally 10 wt% to 20 wt%, optionally 10 wt% to 15 wt%, or optionally 10 wt% to 12 wt%, based on the total weight of the entrained polymer.

[0050] Optionally, in any embodiment, the entrained polymer may be a two-phase blend comprising 20% ​​to 50% by weight of the adsorbent and 50% to 80% by weight of a base polymer (such as polypropylene). The base polymer is not particularly limited.

[0051] Optionally, in any embodiment, the entrained polymer may be a three-phase blend comprising 20% ​​to 45% by weight of the adsorbent, 30% to 75% by weight of the base polymer (such as polypropylene), and 1% to 12% by weight of the channeling agent. The base polymer and the channeling agent are not particularly limited.

[0052] The method of producing the entrained polymer 10 according to the present invention is not particularly limited. An example includes blending a base polymer 25 and a channeling agent 35. An active agent 30 is blended into the base polymer 25 either before or after the addition of the channeling agent 35. All three components are uniformly distributed within the entrained polymer 10 mixture. The entrained polymer thus prepared contains at least two or three phases.

[0053] The form of the entrained polymer is not limited. Optionally, such entrained polymer may be formed into a component in the form of a film, sheet, disk, pellet, packaging material, container, cover, plug, cap, lid, insert, stopper, cork, gasket, seal, washer, liner, or ring. For example, when in the form of a film (e.g., extruded film), the entrained polymer film has a thickness of 0.1 mm to 1.0 mm, preferably 0.2 mm to 0.6 mm, optionally about 0.2 mm or 0.3 mm.

[0054] Optionally, in any embodiment, the entrained polymer is provided within a flexible packaging material, for example as a film. For example, the film may be provided within a flexible pouch. Alternatively, the film may be provided in a blister pack. Exemplary blister packs utilizing atmospherically modified polymer films are disclosed in U.S. Pat. No. 6,279,736 and WO2018 / 145099, each of which is incorporated herein by reference in its entirety. In any embodiment, the blister pack comprises a backing and a cover attached to the backing, the combination of the cover and the backing forming at least one cavity for containing at least one entrained polymer film according to the present invention and at least one product. Optionally, the product releases formaldehyde within the cavity, and the entrained polymer film sorbs formaldehyde. Optionally, the cover is a thermoformed polymer and the backing comprises a foil. Optionally, the entrained polymer film is adhered to the backing. Optionally, in any embodiment, sorption of formaldehyde by the entrained polymer inhibits or prevents formaldehyde degradation of the stored product.

[0055] In any embodiment, the entrained polymer is used as a formaldehyde sorbent to prevent undesirable conversion of gelatin. Gelatin or gelatine is a translucent, colorless, flavorless food ingredient derived from collagen harvested from animal body parts. It is brittle when dry and gummy when moist. It can also be referred to as hydrolyzed collagen, collagen hydrolysate, gelatine hydrolysate, hydrolyzed gelatin, and collagen peptides after undergoing hydrolysis. It is commonly used as a gelling agent in food, drug, pharmaceutical, and vitamin capsules, photographic film and paper, and cosmetics. Gelatin is an irreversible hydrolyzed form of collagen, where hydrolysis reduces protein microfibrils to smaller peptides. The entrained polymer composition of the present invention can optionally be used to improve the integrity and stability of gelatin capsules in the pharmaceutical industry, which is important for maintaining the safety and efficacy of the pharmaceutical product held within the capsule. Formaldehyde causes cross-linking of gelatin particles. The formaldehyde scavenging properties of the activated carbon in the entrained polymer act to reduce the amount of formaldehyde in the composition of the gelatin reducing cross-linking. Reduced cross-linking of the gelatin particles improves the integrity of the gelatin capsule which can affect the chemical or physical properties of the pharmaceutical product within the gelatin capsule, thereby affecting its safety or efficacy.

[0056] In any embodiment, other substituents may be added to the polymer composition of the present invention to increase the desiccant properties or impart other desired properties for the end use application. The use of a combination of active agents may provide certain advantages. For example, activated carbon is known to absorb formaldehyde from the environment in an amount that is temperature dependent, decreasing with increasing temperature. The polymer composition of the present invention may be combined with other components that adsorb formaldehyde at higher temperatures. In any embodiment, a mixture of activated carbon particles is combined with a multivalent polymer, such as hydroxyethyl cellulose, glycerol, and ambient moisture, and functions to remove formaldehyde from the air at room temperature, i.e., about 25°C, as well as at elevated temperatures, e.g., 50°C. Activated carbon absorbs less formaldehyde at temperatures higher than room temperature, but the multivalent polymer composition reacts with more formaldehyde at temperatures higher than room temperature. Thus, the use of a mixture of a multivalent polymer composition and activated carbon captures formaldehyde at a variety of temperature ranges.

[0057] According to any embodiment, a method is provided herein for reducing the amount or level of formaldehyde in a chamber or container by providing the object and the entrained polymer composition of the present invention therein. In certain embodiments, the method includes placing the polymer composition of the present invention in a container or packaging material that is then sealed. Such a method may improve the preservation and shelf life extension of products such as pharmaceuticals, cosmetics, food (such as, but not limited to, fruits, vegetables, and other produce, fish, poultry, meat, and others), herbs, tobacco, cannabis, and any other object that may emit or release some amount of formaldehyde. In one such embodiment, a method is provided for preserving a gelatin-containing product. The method includes storing a gelatin-containing product in a container that includes the entrained polymer composition or material of the present invention.

[0058] Other methods and materials utilizing the entrained polymer compositions disclosed herein to remove gaseous formaldehyde from the atmosphere, from liquids, or from enclosed chambers or containers may be practiced without departing from the spirit and scope of the present invention. EXAMPLES

[0059] The following examples are illustrative embodiments of the practice of the invention and should not be construed as limitations on the invention or claims.

[0060] Two samples of entrained polymer compositions according to the present invention were prepared having a 70% concentration of high density polyethylene polymer (HDPE), 30% concentration of activated carbon, based on the total weight of the polymer composition. The activated carbon of sample 1 was treated with acid wash and steam for activation. The activated carbon of sample 2 was treated with steam only. The polymer compositions were extruded into 1 inch by 1 inch film samples having a thickness of less than 1 mm. Each sample film was placed in a chamber, the chamber was sealed, and the results were recorded. The test chamber contained a formaldehyde concentration of 150 ppm at the start of the experiment and was maintained at ambient conditions of 22° C. The formaldehyde concentration in the chamber was monitored over a period of about 12 days. The formaldehyde uptake of film samples 1 and 2 is plotted in FIG. 6, with 100% indicating a starting formaldehyde concentration of 150 ppm. The results showed that the level of formaldehyde in the test chamber was significantly reduced, as shown in FIG. 6. Based on the results shown in Figure 6, compared to the amount of formaldehyde measured in the test chamber at the beginning of the test period, the percentage of formaldehyde decreased by about 25%, resulting in about a 75% reduction in formaldehyde due to sorption by the polymer composition of the present invention. A control sample of HDPE polymer film (without any activated carbon or other sorbent) enclosed in the test chamber under the same conditions did not show a reduction in formaldehyde levels.

[0061] The amount of formaldehyde within the enclosure can be further reduced by providing additional test film strips within the container or by increasing the loading level of activated carbon within the polymer composition.

[0062] Although the technology of the present disclosure has been described in detail, it will be apparent to those skilled in the art that various changes and modifications can be made therein with respect to specific examples thereof without departing from the spirit and scope thereof. Therefore, it is believed that the technology of the present disclosure is not limited to the specific embodiments disclosed, but is intended to encompass modifications within the spirit and scope of the technology of the present disclosure.

Claims

1. 1. A process for making a polymer composition for formaldehyde sorption comprising: (a) providing a base polymer; (b) adding activated carbon to the base polymer; (c) optionally adding a channeling agent to the base polymer; The process wherein the formaldehyde is contained in air, a gas, or a liquid.

2. 10. The process of claim 1, wherein the activated carbon is added to the base polymer in the form of a powder, crushed, granular, pelleted, spherical, cylindrical, fibrous, or honeycomb.

3. 3. The process of claim 1 or 2, further comprising the step of activating the activated carbon by contacting the polymer composition with a liquid or vapor.

4. 10. The process according to any one of the preceding claims, wherein the concentration of activated carbon in the polymer composition is in the range of 1% to 70% by weight, relative to the total weight of the polymer composition.

5. 10. The process of any one of the preceding claims, wherein the polymer composition is a monolithic material and is at least two-phase or at least three-phase.

6. 10. The process of any one of the preceding claims, wherein the distribution of activated carbon within the base polymer of the polymer composition is essentially homogeneous.

7. 2. The process of any one of the preceding claims, wherein the base polymer is in the range of 10% to 80%, optionally 20% to 70%, optionally 30% to 60%, optionally 40% to 50%, optionally 45% to 65%, optionally 45% to 60%, optionally 45% to 55%, optionally 50% to 70%, optionally 50% to 60%, optionally 55% to 65%, optionally 55% to 60% by weight of the entrained polymeric material.

8. 10. The process of any one of the preceding claims, wherein the base polymer is selected from polypropylene, polyethylene, polyisoprene, polyhydroxyalkanoates (PHAs), polylactic acid (PLA), polybutylene succinate (PBS), polyhexene, polybutadiene, polybutene, polysiloxane, polycarbonate, polyamide, ethylene-vinyl acetate copolymer, ethylene-methacrylate copolymer, polyvinyl chloride (PVC), polystyrene, polyester, polyanhydrides, polyacrylianitrile, polysulfone, polyacrylate, acrylic, polyurethane, polyacetal, polyvinylpyrrolidone (PVP), copolymers, or combinations thereof.

9. 20. The process according to any one of the preceding claims, wherein the amount of the channelling agent is in the range from 1 wt% to 25 wt%, optionally from 2 wt% to 15 wt%, optionally from 5 wt% to 20 wt%, optionally from 8 wt% to 15 wt%, optionally from 10 wt% to 20 wt%, optionally from 10 wt% to 15 wt%, or optionally from 10 wt% to 12 wt%, relative to the total weight of the polymer composition.

10. 13. The process of any one of the preceding claims, wherein the channeling agent is included and is selected from polyethylene glycol (PEG), ethylene-vinyl alcohol (EVOH), polyvinyl alcohol (PVOH), glycerin polyamine, polyurethane, polycarboxylic acid, propylene oxide polymerisate-monobutyl ether, propylene oxide polymerisate, ethylene vinyl acetate, nylon 6, nylon 66, or combinations thereof.

11. 10. The process of any one of the preceding claims, wherein the polymer composition is formed by extrusion, injection molding, blow molding, vacuum forming, or hot melt extrusion.

12. 10. The process of any one of the preceding claims, wherein the polymer composition is formed into a granule, pellet, film, sheet, disc, cover, plug, cap, lid, insert, stopper, gasket, seal, washer, liner, ring, container, or packaging material.

13. 10. The process of any one of the preceding claims, further comprising adding the polymer composition to a packaging material selected from plastic, paper, glass, metal, ceramic, synthetic resin, or combinations thereof.

14. 10. The process of any one of the preceding claims, wherein the polymer composition adsorbs or absorbs up to 50%, optionally up to 60%, optionally up to 70%, or optionally up to 80% of ambient formaldehyde over a period of 15 days.

15. 1. A process for reducing the amount of formaldehyde in a sealed chamber or container, comprising: (1) preparing a polymer composition, the polymer composition comprising (a) a base polymer, (b) activated carbon, and optionally (c) a channeling agent; and (2) enclosing the polymer composition in the chamber or container, wherein the amount of formaldehyde in the sealed chamber or container is reduced.

16. 16. The process of claim 15, further comprising disposing a formaldehyde-emitting object in the chamber or container, wherein the polymer composition reduces the amount of formaldehyde emitted by the object.

17. 17. The process of claim 15 or 16, further comprising the step of activating the activated carbon by contacting the polymer composition with a liquid or vapor.

18. The method of any one of claims 15 to 17, wherein the polymer composition is not in physical contact with the formaldehyde-emitting entity.

19. 19. The process of any one of claims 15 to 18, wherein the amount of formaldehyde in the sealed chamber or container is reduced by 1 to 100% compared to the level of formaldehyde in the container before encapsulating the polymer composition.

20. 10. The process of any one of the preceding claims, wherein the polymer composition is provided in a container, box, tray, carton, bottle, vessel, pouch, bag, sachet, packet, gel pack, blister pack, or packaging material.

21. 2. The process of any one of the preceding claims, wherein the activated carbon is impregnated carbon, optionally tris(hydroxymethyl)aminomethane impregnated carbon.

22. 2. The process of any one of the preceding claims, wherein the base polymer comprises polypropylene, the activated carbon comprises tris(hydroxymethyl)aminomethane, and optionally the channeling agent comprises polyethylene glycol.

23. The process according to any one of claims 15 to 22, wherein the object is a food product, a herb, a medicine or a cosmetic product.

24. A polymeric composition prepared by the method of any one of claims 1 to 23.

25. 25. The polymer composition of claim 24, wherein the polymer composition is activated by contact with a liquid or vapor.

26. 26. The polymer composition according to claim 24 or 25, wherein the concentration of activated carbon in the polymer composition is in the range of 1% to 70% by weight, relative to the total weight of the polymer composition.

27. The polymer composition according to any one of claims 24 to 26, wherein the polymer composition is a monolithic material and is at least two-phase or at least three-phase.

28. The polymer composition of any one of claims 24 to 27, wherein the distribution of activated carbon within the base polymer of the polymer composition is essentially homogeneous.

29. 29. The polymer composition of any one of claims 24 to 28, wherein the base polymer is in the range of 10% to 80%, optionally 20% to 70%, optionally 30% to 60%, optionally 40% to 50%, optionally 45% to 65%, optionally 45% to 60%, optionally 45% to 55%, optionally 50% to 70%, optionally 50% to 60%, optionally 55% to 65%, optionally 55% to 60% by weight of the entrained polymeric material.

30. 30. The polymer composition of any one of claims 24 to 29, wherein the base polymer is selected from polypropylene, polyethylene, polyisoprene, polyhydroxyalkanoates (PHAs), polylactic acids (PLAs), polybutylene succinate (PBS), polyhexene, polybutadiene, polybutenes, polysiloxanes, polycarbonates, polyamides, ethylene-vinyl acetate copolymers, ethylene-methacrylate copolymers, polyvinyl chloride (PVC), polystyrene, polyesters, polyanhydrides, polyacrylonitriles, polysulfones, polyacrylates, acrylics, polyurethanes, polyacetals, polyvinylpyrrolidones (PVPs), copolymers, or combinations thereof.

31. 31. The polymer composition of any one of claims 24 to 30, wherein the amount of the channeling agent is in the range of from 1 wt% to 25 wt%, optionally from 2 wt% to 15 wt%, optionally from 5 wt% to 20 wt%, optionally from 8 wt% to 15 wt%, optionally from 10 wt% to 20 wt%, optionally from 10 wt% to 15 wt%, or optionally from 10 wt% to 12 wt%, relative to the total weight of the polymer composition.

32. 32. The polymer composition of any one of claims 24 to 31, wherein the channeling agent is included and is selected from polyethylene glycol (PEG), ethylene-vinyl alcohol (EVOH), polyvinyl alcohol (PVOH), glycerin polyamine, polyurethane, polycarboxylic acid, propylene oxide polymerisate-monobutyl ether, propylene oxide polymerisate, ethylene vinyl acetate, nylon 6, nylon 66, or combinations thereof.

33. The polymer composition of any one of claims 24 to 32, wherein the polymer composition is formed by extrusion, injection molding, blow molding, vacuum forming, or hot melt extrusion.

34. 34. The polymer composition of any one of claims 24 to 33, wherein the polymer composition is formed into a granule, pellet, film, sheet, disc, cover, plug, cap, lid, insert, stopper, gasket, seal, washer, liner, ring, container, or packaging material.

35. 35. The polymer composition of any one of claims 24 to 34, further comprising adding the polymer composition to a packaging material selected from plastic, paper, glass, metal, ceramic, synthetic resin, or combinations thereof.

36. 36. The polymer composition of any one of claims 24 to 35, wherein the polymer composition adsorbs or absorbs up to 50%, optionally up to 60%, optionally up to 70%, or optionally up to 80% of ambient formaldehyde over a period of 15 days.

37. The polymer composition of any one of claims 24 to 36, provided within a container, box, tray, carton, bottle, vessel, pouch, bag, sachet, packet, gel pack, blister pack, or packaging material.

38. 38. The polymer composition of any one of claims 24 to 37, wherein the polymer composition comprises activated carbon which is impregnated charcoal, optionally tris(hydroxymethyl)aminomethane impregnated charcoal.

39. 39. The polymer composition of any one of claims 24 to 38, wherein the polymer composition comprises polypropylene as the base polymer, tris(hydroxymethyl)aminomethane as the activated carbon, and optionally polyethylene glycol as the channeling agent.

40. The polymer composition according to any one of claims 24 to 39, wherein the polymer composition is in the form of a film and is provided in a blister pack.

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