Packaging patch with sterile sealing layer
阅读说明：本技术 具有消毒密封层的包装补片 (Packaging patch with sterile sealing layer ) 是由 R·贾因 C·E·卡尔布 于 2017-12-28 设计创作，主要内容包括：一种包装物包括补片和包装膜。该补片包含支撑物以及包含亚氯酸根离子的密封层。该支撑物是可渗透二氧化氯的。该包装膜具有限定用于安置物品的包装物的至少一部分内部空间的内表面。该包装膜基本上不可渗透二氧化氯并且是对紫外光透明的。通过该密封层将该补片固定到该包装膜的内表面上。可以通过以下过程产生二氧化氯：使该包装物经受紫外(UV)光以使得该UV光到达该补片的密封层从而将亚氯酸根离子转化为二氧化氯。(A wrapper includes a patch and a packaging film. The patch includes a support and a sealing layer including chlorite ions. The support is permeable to chlorine dioxide. The packaging film has an inner surface defining at least a portion of an interior space of a package for positioning the articles. The packaging film is substantially impermeable to chlorine dioxide and is transparent to ultraviolet light. The patch is secured to the interior surface of the packaging film by the sealing layer. Chlorine dioxide can be generated by the following process: the wrapper is subjected to Ultraviolet (UV) light such that the UV light reaches the sealing layer of the patch to convert the chlorite ion to chlorine dioxide.)
1. A film having first and second major surfaces, the film comprising:
a support permeable to chlorine dioxide and defining a first major surface of the membrane; and
a sealing layer comprising chlorite ions, wherein the sealing layer is in contact with the support and defines a second major surface of the membrane, and wherein the sealing layer is configured for securing the membrane to another structure.
2. The membrane of claim 1, wherein the support comprises one or more layers.
3. The film of claim 1 or claim 2, wherein the support is opaque to ultraviolet light having a wavelength of about 365nm, opaque to ultraviolet light having a wavelength of about 312nm, or opaque to ultraviolet light having a wavelength in the range of from about 300nm to about 390 nm.
4. The membrane of any one of claims 1 to 3, wherein the support comprises a nonwoven material.
5. The membrane of any one of claims 1 to 4, wherein the support comprises polyethylene.
6. The film of claim 5, wherein the polyethylene comprises polyethylene fibers.
7. The film of claim 6, wherein the polyethylene fibers comprise high density polyethylene fibers.
8. The film of any one of claims 1 to 7, wherein the sealing layer comprises a heat sealable polymer composition.
9. The film of claim 8, wherein the heat-seal polymer comprises a polyolefin.
10. The film of any one of claims 1 to 7, wherein the sealing layer comprises a pressure sensitive adhesive.
11. The film of any one of claims 1 to 10, wherein the chlorite ion is present in the sealing layer at a concentration of from about 0.1 wt.% to about 70 wt.%.
12. The film of any one of claims 1 to 11, wherein the film is in the form of a sheet.
13. The film of any one of claims 1 to 11, wherein the film is in the form of a patch.
14. A package, comprising:
a packaging film having an inner surface defining at least a portion of the interior space of the package for positioning an item, wherein the packaging film is substantially impermeable to chlorine dioxide; and
a film in the form of a patch according to claim 13, wherein the patch is secured to the interior surface of the packaging film by the sealing layer, and
wherein the packaging film is transparent to ultraviolet light having a wavelength of about 254nm at a portion where the patch is secured to the packaging film.
15. A method, the method comprising:
providing a package according to claim 14; and is
The package is subjected to ultraviolet light having a wavelength of about 254nm to generate chlorine dioxide from chlorite ions in the seal layer of the patch.
16. The method of claim 15 wherein the package is subjected to a sufficient amount of ultraviolet light to produce a concentration of chlorine dioxide of at least about 10ppm in the interior space.
17. The method of claim 15 or 16, wherein the wrapper comprises a first side and a second side opposite the first side, and wherein the packaging film having an interior surface on which the patch is secured defines the first side of the wrapper, and wherein (i) a second packaging film defines the second side of the wrapper, or (ii) a portion of the first packaging film forms the second side of the wrapper in an area on which the patch is not secured, and wherein the ultraviolet light is applied on the first side from a location outside the wrapper toward the interior surface of the polymer wrapper on which the patch is secured.
18. The method of claim 17, wherein at least the second side of the package is transparent to ultraviolet light having a wavelength from about 300nm to about 390nm and the patch is opaque to ultraviolet light having a wavelength from about 300nm to about 390nm, and wherein the method further comprises subjecting the package to ultraviolet light having a wavelength from about 300nm to about 390nm applied from a location external to the package on the second side such that the opaque patch prevents a substantial amount of the ultraviolet light having a wavelength from about 300nm to about 390nm from reaching the sealing layer containing the chlorite ions, wherein the ultraviolet light having a wavelength from about 300nm to about 390nm accelerates degradation of the generated chlorine dioxide.
19. The method of claim 17, wherein at least the second side of the package is transparent to ultraviolet light having a wavelength of about 365nm and the patch is opaque to ultraviolet light having a wavelength of about 365nm, and wherein the method further comprises subjecting the package to ultraviolet light having a wavelength of about 365nm applied on the second side from a location outside the package such that the opaque patch prevents a substantial amount of the ultraviolet light having a wavelength of about 365nm from reaching the sealing layer containing the chlorite ions, wherein the ultraviolet light having a wavelength of about 365nm accelerates degradation of the generated chlorine dioxide.
20. The method of claim 17, wherein at least the second side of the package is transparent to ultraviolet light having a wavelength of about 312nm and the patch is opaque to ultraviolet light having a wavelength of about 312nm, and wherein the method further comprises subjecting the package to ultraviolet light having a wavelength of about 365nm applied on the second side from a location outside the package such that the opaque patch prevents a substantial amount of the ultraviolet light having a wavelength of about 312nm from reaching the sealing layer containing the chlorite ions, wherein the ultraviolet light having a wavelength of about 312nm accelerates degradation of the generated chlorine dioxide.
Technical Field
The present disclosure relates generally to the release of chlorine dioxide (ClO) on demand2) Gas-provided group with chloriteCompositions, sheets, patches and packages, and methods for releasing chlorine dioxide from such compositions, sheets, patches and packages.
Background
The package may incorporate a source of chlorite ions which may be activated by ultraviolet light to release chlorine dioxide to deodorize or sterilize the contents of the package. These packages employ multilayer films that include chlorite ions in one layer of the film. The film or films are sealed to define an interior of the package into which chlorine dioxide can be released upon activation of the chlorite ion. The contents of these sealed packages can be sterilized if the concentration of chlorine dioxide generated is maintained high enough for a sufficient time. It has been found that chlorine dioxide, once generated, spontaneously degrades over time to various oxychloride ions (Cl) under ambient room light and ambient temperature-、ClO-、ClO2 -、ClO3 -) This follows first order kinetics, which depend on the initial ClO generated2The concentration has a half-life between 2-3 hours. It may take between 12 and 48 hours for the chlorine dioxide concentration in the package to reach a sufficiently low level to safely open the package.
Incorporating a source of chlorite ions into a layer of a multilayer packaging film presents several challenges. For example, compounding or extruding sodium chlorite with a polymeric melt is challenging because sodium chlorite thermally degrades at processing temperatures greater than 180 ℃, which reduces the active ingredients in the final formulation. In addition, this presents a safety hazard due to the possibility of a thermal runaway event. This is because sodium chlorite decomposes into sodium chlorate and sodium chloride in an exothermic reaction (at temperatures (T) exceeding 180 ℃) which can lead to a rapid rise in temperature which can in turn lead to the exothermic decomposition of sodium chlorate (T >250 ℃ -300 ℃) into sodium chloride and gaseous oxygen, which is a fire hazard. Due to the thermal sensitivity of sodium chlorite, existing film structures and manufacturing specifications that often incorporate polymers with high processing temperatures (>180 ℃) require re-engineering and design to safely and feasibly incorporate a source of chlorite ions into the layers of packaging film. Furthermore, printing on the outside of a package made from the above-mentioned multilayer film may change the amount of chlorine dioxide that can be released, as the printing may block the transmission of ultraviolet light onto the chlorite containing layer.
Disclosure of Invention
The present disclosure relates, among other things, to incorporating a source of chlorite ions into a patch or a seal layer of a sheet used to form the patch. A patch having a sealing layer comprising a source of chlorite ions may be affixed to the interior surface of the package or to the surface of the film used to form the package. Chlorine dioxide is generated by exposing the sealing layer of these patches to ultraviolet light.
In various embodiments of the present disclosure, a film is described that may be in the form of, for example, a patch. The membrane has a support layer permeable to chlorine dioxide and defining a first major surface of the membrane. The film also includes a sealing layer including chlorite ions. The sealing layer is in contact with the support layer and defines a second major surface of the film. The sealing layer is configured to secure the film to an interior surface of another structure, such as a package. Preferably, the support is opaque to ultraviolet light. The sealing layer may comprise any suitable sealing composition, such as a heat sealable polymer composition, a pressure sensitive adhesive composition, or the like.
In various embodiments of the present disclosure, a package is described. The wrapper comprises a film in the form of a patch and comprises a packaging film. The patch includes a sealing layer containing chlorite ions. The packaging film has an inner surface defining at least a portion of an interior space of a package for positioning the articles. The packaging film is substantially impermeable to chlorine dioxide. The film in the form of a patch is secured to the inner surface of the packaging film by the sealing layer. A portion of the film to which the wrapper is secured is transparent to ultraviolet light.
In various embodiments of the present disclosure, a method is described. The method includes providing a wrapper having a wrapping film and a patch secured to an inner surface of the wrapping film. The patch includes a support and a sealing layer containing chlorite ions. The method further includes subjecting the package to ultraviolet light (UV254) having a wavelength of about 254nm to generate chlorine dioxide from chlorite ions in the seal layer of the patch. UV254 may be directed through the wrapper to the sealing layer of the patch. The method may further comprise subjecting the package to ultraviolet light having a wavelength in the range from about 300nm to about 390nm, such as about 365nm (UV365), to accelerate degradation of the generated chlorine dioxide. Ultraviolet light having a wavelength in the range of from about 300nm to about 390nm may be directed through the wrapper to the support of the patch, which if UV opaque, may prevent a substantial amount of the ultraviolet light having a wavelength in the range of from about 300nm to about 390nm from reaching the sealing layer containing chlorite ions, thereby preventing further generation of chlorine dioxide.
The various embodiments of the methods, compositions, sheets, patches, and packages described herein provide one or more advantages over currently available or previously described methods, compositions, sheets, patches, and packages incorporating sources of chlorite ion to generate chlorine dioxide. For example, these patches may be applied to any existing packaging (e.g., including a barrier layer) that is transparent to ultraviolet light and substantially impermeable to chlorine dioxide. Thus, major redesign and changes to the manufacturing specifications that incorporate on-demand chlorine dioxide sterilization into the package are not required. Furthermore, only the portion of the wrapper to which the patch is applied needs to be transparent to ultraviolet light, leaving the remaining wrapper available for printing, labeling, or other modifications that may affect the transparency of ultraviolet light. Further, the patch is applied to the wrapper such that the sealing layer of the patch contacts the interior surface of the packaging film, preventing the item stored in the wrapper from contacting the source of chlorite ions. The absence of contact between the source of chlorite ions and the item within the package is beneficial for sensitive items such as, for example, electronic items, items used in the medical field, or items containing pharmaceuticals.
In some preferred embodiments, the sealing composition used to form the sealing layer is applied to the patch or sheet used to form the patch under ambient conditions or at a temperature substantially lower than the temperature associated with thermal compounding or extrusion. Thus, the patch and associated package can be handled and manufactured more safely than existing methods for incorporating chlorite ions, which include high temperature conditions. Furthermore, because the heat sensitive chlorite ions are subjected to lower temperature processing in some of the preferred embodiments described herein, reduced loss of chlorite ions can be achieved.
The use of a patch comprising a uv light opaque structural layer allows for accelerating the process of chlorine dioxide degradation by applying a source of uv light having a wavelength in the range from about 300nm to about 390 nm. The opaque patch may block ultraviolet light from reaching the sealant layer containing chlorite ions if the light is applied in the appropriate direction. If the source of chlorite ions is blocked from ultraviolet light, ultraviolet light having a wavelength in the range of from about 300nm to about 390nm may accelerate the degradation of chlorine dioxide without producing more chlorine dioxide. Thus, the package can be safely opened in significantly less time than previous methods that allowed spontaneous degradation of chlorine dioxide under ambient conditions. For example, embodiments of the packages and methods described herein allow for sterilization of a safe package open cycle time of about 4 to 6 hours, as opposed to 48 hours for previously available packages and methods.
Additional features and advantages of the presently disclosed subject matter will be set forth in the detailed description which follows, and in part will be readily apparent to those skilled in the art from that description or recognized by practicing the presently disclosed subject matter as described herein, including the detailed description which follows, the claims, as well as the appended drawings.
It is to be understood that both the foregoing general description and the following detailed description present embodiments of the disclosed subject matter, and are intended to provide an overview or framework for understanding the nature and character of the disclosed subject matter as it is claimed. The accompanying drawings are included to provide a further understanding of the presently disclosed subject matter and are incorporated in and constitute a part of this specification. The drawings illustrate various embodiments of the disclosed subject matter and, together with the description, serve to explain the principles and operations of the disclosed subject matter. Moreover, the drawings and description are meant to be illustrative only and are not intended to limit the scope of the claims in any way.
Drawings
The following detailed description of specific embodiments of the present disclosure can be best understood when read in conjunction with the following drawings, where like structure is indicated with like reference numerals.
Fig. 1 is a schematic cross-sectional view of an embodiment of a film that may be in the form of a patch.
Fig. 2 is a schematic plan view of an embodiment of a sheet from which patches may be formed.
Fig. 3 is a schematic plan view of an embodiment of a patch secured to a surface of an embodiment of a packaging film.
Fig. 4 is a schematic cross-sectional view of an embodiment of a patch secured to a surface of an embodiment of a packaging film.
Figure 5 is a schematic cross-sectional view of an embodiment of a package.
Fig. 6A-B are schematic side views of embodiments of packages exposed to ultraviolet light according to embodiments of a method.
Fig. 7 is a graph showing chlorine dioxide release from a patch in a self-sealing package after exposure to ultraviolet light (UV254) having a wavelength of 254 nm. Exposure to UV254 was performed at a distance of 2 inches from these UV bulbs using XL-1500UV crosslinker units (containing six 16W UV254 bulbs). The headspace of the envelope (in the form of a bag) is about 200mL by volume. Data were averaged from three replicates.
Fig. 8 is a graph of the concentration of chlorine dioxide within a package with a patch as a function of time. Each data point was replicated three times.
Figure 9 is a graph of chlorine dioxide concentration in a package with a patch versus the duration of exposure to ultraviolet light having a wavelength of 365 nm.
The schematic drawings are not necessarily drawn to scale. The same reference numerals are used in the drawings to refer to the same parts, steps, etc. It should be understood, however, that the use of a number to refer to a component in a given figure is not intended to limit the component in another figure labeled with the same number. Moreover, the use of different numbers to refer to components is not intended to indicate that the different numbered components cannot be the same or similar to other numbered components.
Detailed Description
Reference will now be made in detail to various embodiments of the presently disclosed subject matter, some of which are illustrated in the accompanying drawings.
The present disclosure relates, among other things, to incorporating a source of chlorite ions into a patch or a seal layer of a sheet used to form the patch. The patch may be secured to the inner surface of the wrapper or to the surface of the film used to form the wrapper via the sealing layer. The wrapper may be exposed to ultraviolet light to generate chlorine dioxide from chlorite ions in the seal layer of the patch.
The sealant layer of the patch may contain any suitable amount of chlorite ions. The amount of chlorite ion in the sealant layer or composition is preferably sufficiently high to deodorize, disinfect, or sterilize an article placed in the interior of the package to which the patch is secured. The concentration of chlorite ions in the seal layer may vary depending on the thickness of the seal layer, the surface area of the patch used (length x width), and the volume inside the package, as well as the desired effect (e.g., deodorizing, disinfecting, or sterilizing). Any suitable amount of chlorite ion can be included in the sealing layer or sealing composition to deodorize, disinfect, or sterilize the interior of the package, and the contents of the package can vary depending on the interior volume of the package.
Any suitable source of chlorite ions may be included in the sealing layer or sealing composition. Typically, the source of chlorite ion is chlorite. As used herein, "chlorite" is not limited to embodiments in which anions and cations form solid crystals, but also includes virtually any form in which such salts are known to exist, including in aqueous or other solutions or dispersed within a polymer matrix. In some embodiments, the cation in the chlorite salt is an organic cation, and in some embodiments, the cation in the chlorate salt is inorganic. In some such embodiments, the chlorite is sodium chlorite, potassium chlorite, calcium chlorite, magnesium chlorite, lithium chlorite, or ammonium chlorite. In some embodiments, the chlorite is sodium chlorite.
Typically, the sealing layer will contain less than about 70% by weight chlorite so that the sealing layer can maintain effective sealing characteristics, and the sealing layer will typically contain at least about 0.1% by weight chlorite so that a sufficient amount of chlorine dioxide can be generated. The sealing layer can include any suitable amount of chlorite. The amount of chlorite can be varied to help control the ClO produced2The amount of (c). In non-limiting examples, the weight percent of chlorite salt is, for example, 0.1%, 1%, 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, or 70% of the weight of the sealing layer, or any amount in between. In some embodiments, the lower range of the weight of chlorite salt can be, for example, 0.1%, 1%, 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, or 65% of the weight of the sealing layer composition, while the upper range of the weight of chlorite salt can be 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, or 70% of the weight of the sealing layer composition. The present disclosure includes all weight percent ranges defined by any combination of these lower and upper limit limits.
The patch or the sheet used to form the patch may include any suitable sealing layer containing chlorite ions. As used herein, a "sealing layer" is a layer comprising a composition configured for securing a patch to another structure (e.g., a surface of a wrapper or packaging film) via melt bonding or chemical bonding (e.g., adhesion). For example, the sealing layer may comprise a heat sealable polymer composition, a cold seal adhesive, or a pressure sensitive adhesive.
In use, the sealing layer is the outermost layer of the patch or of the sheet used to form the patch. That is, the sealing layer forms one of the two major surfaces of the patch or sheet. In the case of a patch or sheet having a sealing layer comprising a pressure sensitive adhesive, the patch or sheet may comprise a release liner prior to use. The pressure sensitive adhesive may be disposed between the support and the release liner. The release liner may be removed prior to securing the patch to the package or packaging film.
The sealing layer may comprise any suitable cold seal adhesive. Cold seal adhesives have the ability to form a strong bond to themselves when pressure is applied, but can also be applied to a substrate and rolled up as a dry film for storage without affecting such a bond. Thus, the adhesive must be sufficiently deformable to form a bond under the application of pressure alone, yet sufficiently rigid to resist bonding to the substrate during storage. Such adhesives are well known and used in a variety of applications including as envelope sealants and in food packaging where the application of heat to bond is undesirable.
Conventional cold seal adhesives combine a natural rubber elastomer (e.g., latex) with a tackifier and an ether compound. The cold seal adhesive may contain, for example, 55-60 wt.% of a high ammonia content natural rubber latex emulsion, 30-40 wt.% of a styrene acrylate emulsion, and small amounts of wetting agents, latex stabilizers, thickeners, or other suitable additives. An appropriate amount (as described above) of chlorite can be added to the cold seal adhesive.
Many synthetic alternatives to natural rubber based cold seal adhesives have been developed and may be used. Examples include those commercially available from hangao corporation (Henkel), those described in european published patent application publication No. EP 0338304a, and the like.
The sealing layer may comprise any suitable pressure sensitive adhesive. Pressure sensitive adhesives are materials that hold two surfaces together only by surface contact, which is achieved by a slight initial external pressure. Pressure sensitive adhesives do not require water, solvent, or heat activation and adhere firmly to many different surfaces with minimal pressure.
Examples of suitable pressure sensitive adhesives include acrylate polymer pressure sensitive adhesives, rubber (natural or synthetic thermoplastic elastomers) pressure sensitive adhesives, silicone pressure sensitive adhesives, and the like. The pressure sensitive adhesive may suitably comprise a tackifier such as a rosin ester. The pressure sensitive adhesive may be a solvent-based pressure sensitive adhesive in which rubber or acrylic is dissolved in a solvent and then coated on a support such as a support film. The solvent may evaporate leaving behind a dry tacky pressure sensitive adhesive. The pressure sensitive adhesive may be an emulsion based pressure sensitive adhesive in which the acrylic polymer and other additives are dispersed in water and coated on a support. The water can evaporate leaving a dry tacky pressure sensitive adhesive. The pressure sensitive adhesive may be a hot melt pressure sensitive adhesive in which a thermoplastic rubber or elastomer, a tackifying resin, and a diluent such as a plasticizer are heated until it is fluid, and then coated on a support and cooled.
Any suitable amount of chlorite can be added to the pressure sensitive adhesive composition applied to the support to achieve a pressure sensitive adhesive layer with a suitable concentration of chlorite ions. Preferably, due to the temperature sensitivity of the chlorite ion, the pressure sensitive adhesive is formed by a process that does not include elevated temperatures (e.g., temperatures in excess of 320F.). Thus, hot melt pressure sensitive adhesives are less preferred. Although less preferred, hot melt pressure sensitive adhesives may be used.
The sealing layer may comprise any suitable heat sealing layer. The heat-seal layer may comprise any suitable sealing composition, such as a heat-sealable polymer composition. In some embodiments, the heat sealable polymer composition comprises a polyolefin. "polyolefin" is used broadly herein to include polymers such as polyethylene, ethylene-alpha olefin copolymers (EAOs), polypropylene, polybutylene, ethylene copolymers having a majority amount by weight of ethylene polymerized with a lesser amount of comonomer such as vinyl acetate, and other polymeric resins falling into the "olefin" family of classifications. Polyolefins can be made by a variety of processes well known in the art, including batch and continuous processes using single, staged or continuous reactors, slurry, solution and fluidized bed processes, as well as batch and continuous processes including, for example, homogeneous and heterogeneous systems and one or more catalysts such as Ziegler, Phillips, metallocene, single site and constrained geometry catalysts, to produce polymers having different combinations of properties. Such polymers may be highly branched or substantially linear, and the degree of branching, degree of dispersion, and average molecular weight may vary depending on the parameters and processes selected to make these polymers in accordance with the teachings of the polymer art.
In some embodiments, the heat seal layer comprises a Cyclic Olefin Copolymer (COC), such as an ethylene norbornene copolymer. In some embodiments, the heat seal layer comprises one or more of polyethylene, ethylene vinyl acetate, ethylene-alpha olefin, or polypropylene. In some embodiments, the sealing layer comprises a blend of polymers to achieve suitable or desired properties.
The chlorite ion may be applied to the composition used to form the heat-seal layer in any suitable manner. In some embodiments, the chlorite ion is mixed with the heat sealable polymer composition at a suitable concentration and the mixture is extruded to form the heat seal layer. Preferably, the heat-sealing layer is formed in a manner that does not require high temperatures. For example, a heat sealing layer may be formed from a polyolefin dispersion to which chlorite may be added. An example of a suitable polyolefin dispersion is DowHYPODTMPolyolefin dispersions, e.g. HYPOD from DowTM8501. 8502, 8503, 1001 or 1000.
The sealing layer may have any suitable thickness regardless of the composition or type of sealing layer and the method used to apply the sealing layer. In some embodiments, the patch or the resulting seal layer of the sheet used to form the patch has a thickness of from about 0.1 mil to about 1 mil, such as from about 0.25 mil to about 0.75 mil. When the coating is applied to, for example, a nonwoven material, the coating can be applied at any suitable weight. For example, the dry coating weight can be from about 1 to about 15 pounds per ream, such as from about 3 to about 11 pounds per ream.
Preferably, the sealing layer is transparent to ultraviolet radiation (e.g., at least 10% of the ultraviolet light can be transmitted through the sealing layer).
The sealing layer may be applied to the support in any suitable manner. For example, the sealing layer and the support may be coextruded to form a film, which may be formed into a patch or a sheet from which a patch is formed. The sealing layer may be coated, sprayed, rolled, printed on, adhered to, or otherwise applied to the support. The sealing layer may be arranged over the entire surface of the support or over one or more portions of the surface of the support. In some embodiments, the sealing layer is applied to the entire surface of the support using a gravure or air knife coating process.
The sealing layer may comprise more than one layer, with the proviso that chlorite ions are present in at least one of the layers. The layer containing chlorite ions and any layers between the layer containing chlorite ions and the surface of the sealing layer must be transparent to ultraviolet radiation.
The sealing layer may be applied to any suitable support to form a patch or a sheet for a patch. It is understood that the patch or the sheet used to form the patch is a "film". As used herein, a "film" is a thin structure having a length and width that are significantly greater than its depth or thickness. Typically, the length and width of the film are at least 100 times greater than the thickness of the film, such as at least 1000 times greater than the thickness of the film. Thus, the term "film" may include paper, cloth, nonwoven, and polymeric films.
The film forming the patch or the sheet used to form the patch may have any suitable support. The support is permeable to chlorine dioxide. The support may be formed of a material that is permeable to chlorine dioxide or that can be modified to be permeable to chlorine dioxide. For example, a support that is initially impermeable to chlorine dioxide may be made permeable by perforating the support. Thus, a wide variety of materials may be used to form the support.
Oxygen permeability may serve as an indicator (proxy) of chlorine dioxide permeability. In some embodiments, the support will have an oxygen transmission rate (O2TR) of at least 100cm3/m2/24 hours at 1 atmosphere and 23 ℃, such as at least 250cm3/m2/24 hours at 1 atmosphere. Oxygen transmission rate (O2TR) may be determined by any suitable method. For example, oxygen transmission rate may be determined according to ASTM D3985.
The support may be formed from fibres or material in any other suitable form. In some embodiments, the support comprises a nonwoven material. In thatIn some embodiments, the nonwoven material comprises spun polyolefin fibers, polyester fibers, polyamide fibers, or the like. In some embodiments, the support comprises polyethylene fibers. In some embodiments, the polyethylene fibers comprise high density polyethylene fibers. In some embodiments, the high density polyethylene fibers are flash spun high density polyethylene fibers. One suitable example of a flash spun high density polypropylene fiber is DuPont
In some embodiments, the support is paper or cloth. In some embodiments, the support is a chlorine dioxide permeable or perforated or otherwise modified to be permeable to chlorine dioxide.
The film forming the patch or sheet may comprise, consist essentially of, or consist of a support and a sealing layer comprising chlorite ions. The support may comprise one or more layers provided that chlorine dioxide is permeable through each layer.
The film may be in the form of a sheet from which one or more patches may be formed. For example, the sheet may be punched or cut to form a patch. As used herein, "sheet" includes a roll of film.
Preferably, the support is opaque to ultraviolet radiation, in particular ultraviolet light having a wavelength in the range from about 200nm to about 390 nm. For example, the support blocks transmission of more than 90% or more of the ultraviolet light. In some embodiments, the support blocks transmission of 95% or more of the ultraviolet light. As described in more detail below, having an ultraviolet light opaque support can be helpful in a method for accelerating the decomposition of chlorine dioxide to reduce the amount of time from activating chlorine dioxide to safely open a package that includes a patch having a sealing layer containing chlorite ions.
Examples of materials that may be opaque to ultraviolet light and that may be used to form the support include polymers having aromatic moieties that absorb UV254 nm light, such as polyesters, aromatic polymersPolyamide, polystyrene, and the like. Flash spun high density polyethylene fibers such as those from DuPontMay be opaque to ultraviolet light.
Any suitable wrapper may include a patch having a sealing layer containing chlorite ions. The wrapper may include a packaging film having an inner surface defining at least a portion of an interior space of the wrapper for positioning the item. The packaging film is substantially impermeable to chlorine dioxide. At least a portion of the wrapper to which the patch is secured is transparent to ultraviolet light. The packaging film may comprise a monolayer film or a multilayer film. A patch is secured to the interior surface of the packaging film. The packaging film may be flexible or rigid depending on the type of package being formed. The wrapper may be in the form of a bag, pouch, or other suitable container. The packaging film to which the patch is secured may be, for example, one side of a bag, pouch or container, or may be the lid of a container, such as a thermoformed tray. In some embodiments, the patch is secured to a thermoformed tray or other suitable container formed from the packaging film.
The method used to secure the patch to the surface of the packaging film will depend on the sealing layer of the patch. For example, if the seal layer is a heat seal layer, the patch may be heat sealed to the packaging film. If the seal layer comprises a pressure sensitive adhesive, the patch may be pressed against the packaging film. If the seal layer comprises a cold seal adhesive, the patch may be pressed against the surface of the packaging film comprising the cold seal layer. The cold seal layer may be applied to the entire surface of the packaging film or any suitable portion for securing a patch comprising a cold seal adhesive.
The packaging film can comprise any suitable number of layers. For example, the packaging film may comprise one or more of a sealing layer, a barrier layer, a damage-resistant outer layer, an intermediate layer, an adhesive layer, and the like.
The packaging film may comprise any suitable sealing layer, such as the sealing layers described above with respect to the patch or the sheet used to form the patch. Preferably, the packaging film comprises a heat-seal layer and the film is heat-sealed to itself, another film, or a container, for example, to form a sealed package. The heat sealing may form a hermetic seal. The patch may be secured to the packaging film at any suitable time prior to final sealing of the package. The sealing layer of the packaging film may have an easy-peeling function. If the packaging film comprises a heat-seal layer to form a wrapper, the patch is preferably secured to a sheet of the packaging film before even the film is partially sealed to form the wrapper.
The sealing layer of the packaging film can have any suitable thickness. In some embodiments, the sealing layer of the packaging film has a thickness of 2.5 microns or greater, such as 3 microns or greater. In some embodiments, the sealing layer of the packaging film has a thickness of 25 microns or less.
The packaging film is preferably impermeable to appreciable amounts of chlorine dioxide. For example, the packaging film can have a thickness of less than 150cm at 1 atmosphere and 23 ℃3/m2Oxygen transmission Rate (O) at 24 hours2TR), e.g. less than 100cm at 1 atmosphere3/m2And/24 hours. In some embodiments, the packaging film has less than 10cm at 1 atmosphere and 23 ℃3/m2O/24 hours2TR, e.g. less than 1cm at 1 atmosphere and 23 deg.C3/m2And/24 hours. Oxygen transmission rate (O)2TR) may be determined by any suitable method. For example, oxygen transmission rate may be determined according to ASTM D3985.
To achieve such low permeability, the packaging film may include one or more barrier layers. If included, the barrier layer preferably serves as both a gas barrier and a moisture barrier, although these functions may be provided by separate layers. The barrier layer is preferably a core layer located between and protected by the surface layers. For example, the barrier layer may be in contact with the first surface layer and the adhesive layer or may be sandwiched between two tie layers, between two surface layers, or between a tie layer and a surface layer.
The barrier layer may comprise any suitable material and may be of any suitable thickness. The gas barrier layer may comprise polyvinyl alcohol (PVOH), ethylene vinyl alcohol (EVOH), polyvinylidene chloride (PVDC), polyamide, polyester, polyalkylene carbonate, polyacrylonitrile, nanocomposite, or the like. Preferably, the barrier layer is transparent to ultraviolet light. The thickness of the barrier layer may be selected to provide a desired combination of performance characteristics sought (e.g., with respect to oxygen permeability, water vapor permeability, delamination resistance, etc.).
The bulk layer may be provided to provide additional functionality (e.g., rigidity or heat sealing properties) or to improve machinability, cost, flexibility, barrier properties, etc. Preferred body layers comprise one or more polyolefins such as polyethylene, ethylene-alpha olefin copolymers (EAO), polypropylene, polybutylene, ethylene copolymers having a majority amount by weight of ethylene polymerized with a lesser amount of comonomer such as vinyl acetate, and other polymeric resins falling into the olefin family of classifications. The body layer may have any suitable thickness or may even be omitted for certain applications.
The packaging film may include a damage resistant outer layer. Because the outer layers are visible to the user/consumer in both the single layer and multilayer embodiments, the exterior surface of the packaging film preferably has the desired optical properties and may have a high gloss. Moreover, it preferably withstands contact with sharp objects and provides wear resistance, and for these reasons it is often referred to as a damage resistant layer. Such an outer damage-resistant layer may or may not also serve as a heat-sealable layer, and may therefore comprise one or more suitable polymers, such as polyethylene or polypropylene. As the outer surface layer of the film, this layer is also the outer layer of any package (such as a bag, pouch or other container) made of the packaging film in the most common case, and is therefore subject to handling and destruction, for example, as follows: equipment during packaging, and friction with other packages and shipping containers and storage racks during shipping and storage.
The outer surface layer should be easy to machine (i.e. easy to feed to and operate through a machine, e.g. for transport, packaging, printing or as part of a film or bag manufacturing process). Suitable rigidity, flexibility, crack resistance, modulus, tensile strength, coefficient of friction, printability and optical properties are also often designed into the outer layer by suitable choice of materials. The layer may also be selected to have characteristics suitable for creating desired heat seals, which may be burn-through resistant (e.g., by an impulse sealer) or may be used as a heat sealing surface (e.g., using an overlap seal) in certain package embodiments.
Suitable external surface layers may include: polyamides, polyolefins, cast or oriented nylons, polypropylenes, or copolymers, or blends thereof. The oriented film of this layer or any other layer may be uniaxially oriented or biaxially oriented. The thickness of the outer layer is typically 0.5 to 2.0 mils. Thinner layers may not work well in terms of damage resistance, however, thicker layers, while more expensive, may still be advantageously used to produce films with unique highly desirable puncture and/or damage resistance characteristics.
The packaging films described herein may include an intermediate layer. An intermediate layer is any layer between the outer and inner layers and may include an oxygen barrier layer, an adhesive layer, or a layer having functional properties useful for the film structure or its intended use. Intermediate layers may be used to modify, affect or otherwise alter a number of characteristics: such as printability, machinability, tensile properties, flexibility, rigidity, modulus, engineered delamination, easy-open features, tear properties, strength, elongation, optics, moisture barrier, oxygen or other gas barrier, radiation selectivity or barrier (e.g., to ultraviolet wavelengths), etc., of the trapping structure(s). Suitable intermediate layers may include: an adhesive, an adhesive polymer, paper, oriented polyester, amorphous polyester, polyamide, polyolefin, nylon, polypropylene, or copolymer, or blends thereof. Suitable polyolefins may include: polyethylene, ethylene-alpha olefin copolymers (EAO), polypropylene, polybutylene, ethylene copolymers having a majority amount by weight of ethylene polymerized with a lesser amount of comonomer, such as vinyl acetate, and other polymeric resins falling into the "olefin" family of classifications, LDPE, HDPE, LLDPE, EAO, ionomers, Ethylene Methacrylic Acid (EMA), Ethylene Acrylic Acid (EAA), modified polyolefins such as anhydride grafted ethylene polymers, and the like.
The packaging films as described herein may include one or more adhesive layers (also referred to in the art as "tie layers") that may be selected to promote adhesion of adjacent layers in the multilayer film to each other and to prevent unwanted delamination. The multifunctional layer is preferably formulated to facilitate adhesion of one layer to the other layer by virtue of the compatibility of the materials in that layer with the first and second layers, without the use of a separate adhesive. In some embodiments, the adhesive layer comprises a material found in both the first layer and the second layer. The adhesive layer may suitably be less than 10% and preferably between 2% and 10% of the total thickness of the multilayer film.
The multilayer film may include any suitable number of tie or adhesive layers of any suitable composition. Depending on the composition of the layers in contact with the adhesive layer, each adhesive layer is formulated and positioned to provide a desired level of adhesive between specific layers of the film.
The inner, outer, intermediate or adhesive layers may be formed of any suitable thermoplastic material, for example polyamide, polystyrene, styrene copolymers such as styrene-butadiene copolymers, polyolefins, and in particular members of the polyethylene family (such as LLDPE, VLDPE, HDPE, LDPE, COC, ethylene vinyl ester copolymers or ethylene alkyl acrylate copolymers), polypropylene, ethylene-propylene copolymers, ionomers, polybutylene, alpha-olefin polymers, polyesters, polyurethanes, polyacrylamides, anhydride-modified polymers, acrylate-modified polymers, polylactic acid polymers, or different blends of two or more of these materials.
Various additives may be included in the polymers utilized in one or more of the outer, inner, and intermediate or adhesive layers of a package containing the outer, inner, and intermediate or adhesive layers. For example, one layer may be coated with an anti-blocking powder. Also, conventional antioxidants, antiblock additives, polymeric plasticizers, acids, moisture or gas (e.g., oxygen) scavengers, slip agents, colorants, dyes, pigments, sensates may be added to one or more film layers of the film, or the film may be free of such added ingredients.
The layers, components, additives, etc. of the packaging film may be selected such that the packaging film is transparent to ultraviolet radiation, particularly radiation having a wavelength in the range from about 250nm to about 370 nm.
The packaging films described herein can be made in any suitable manner (e.g., by conventional processes). The process for producing the flexible film may include, for example, a cast film or blown film process, or an extrusion process.
The packaging films described herein can have any suitable thickness. In some embodiments, the packaging film has a total thickness of less than about 50 mils, more preferably, the film has a total thickness of from about 1.0 to 10 mils (25-250 micrometers), such as from about 1 to 5 mils, or from about 2 to 3.5 mils. For example, the entire multilayer film or any individual layer of the multilayer film can have any suitable thickness, including 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, or 50 mils, or any value with an increment between these values of 0.1 or 0.01 mils.
In some embodiments, the packaging films are as thick as 50 mils (1270 microns) or thicker, or as thin as 1 mil (25.4 microns) or thinner. In various embodiments, these packaging films have a thickness of between about 2-4 mils (51-102 microns).
The wrapper may be formed from a film in any suitable manner. In some embodiments, these packages are formed by heat sealing the film to itself, or to another suitable film. In some embodiments, a package such as a pouch is thermoformed from the films. In some embodiments, the film is heat sealed across the opening of the container. The packaging film is preferably sealed to form a package after the patch, which includes a sealing layer containing chlorite ions, is secured to the packaging film. The articles may be placed in a package prior to final sealing. Thus, once the packaging film is sealed to form the final package, the articles are disposed within the interior space of the package.
Any suitable article may be disposed in the packages described herein. Examples of suitable articles include food products, pharmaceutical products, laboratory devices, and medical devices. Examples of suitable agricultural products that may be packaged within the films described herein include lettuce, grapes, spinach, or the like. Any suitable medical device may be disposed in a package comprising a multilayer packaging film as described herein. For example, catheters, such as balloon dilation catheters, guide catheters, aspiration catheters, and diagnostic catheters; a vacuum blood collection tube; yankauer tube (yankauer); an enteral feeding kit; gowns and drapes; a coronary stent; surgical tools and equipment, sensors or other electronic medical devices, various forms of endoscopes including capsule endoscopes; or the like may be disposed within a sealed package as described herein.
Chlorine dioxide may be generated in the interior of a package that includes a patch having a sealing layer containing a source of chlorite ions, which patch is secured to the interior surface of the packaging film in any suitable manner. For example, ultraviolet light may be directed through the packaging film to the seal layer of the patch to generate chlorine dioxide gas from these chlorite ions. Chlorine dioxide gas can permeate through the support of the patch to the interior of the package.
The generation of chlorine dioxide from chlorite ions can be enhanced with moisture. The package may be exposed to moisture before, during, or after subjecting the package to ultraviolet light. In some embodiments, the step of exposing the package to moisture is performed by contacting the package with a humidified gas comprising water vapor. In some such embodiments, the humidified gas is heated above room temperature. In some such embodiments, the humidified gas comprises steam. In some embodiments, ambient humidity may be used. In some embodiments, the water vapor is provided by storing the contents or items of the package within the package. For example, if the item stored within the package is a food product, such as an agricultural product, the item can provide sufficient moisture to enhance the generation of chlorine dioxide by ultraviolet light. In some embodiments, the water may be applied to the patch before, during, or after the patch is secured to the wrapper or packaging film used to form the wrapper. In some embodiments, the moisture may be replenished by placing the wetted parts in a package. For example, a moistened tissue paper or other suitably moistened substrate may be placed in the package to replenish moisture. Additional information regarding the application of moisture and UV light to generate chlorine dioxide from a composition or package comprising chlorite ions is disclosed, for example, in PCT patent application publication No. WO2017/031345, which is hereby incorporated by reference in its entirety to the extent that the application does not conflict with the disclosure presented herein.
The ultraviolet light can be directed to the sealing layer of the patch for a sufficient time to produce an effective amount of chlorine dioxide release within the interior space of the sealed package. As used herein, an "effective amount" of chlorine dioxide (ClO)2) Liberation of gas means that the ClO liberated2The amount of gas is effective to achieve its intended effect. For example, the amount of chlorine dioxide gas released may be effective to disinfect or deodorize, or both, the interior of the package and the items within the package. The amount of chlorine dioxide gas released may be effective to sterilize the interior of the package as well as the items within the package.
As used herein, "deodorizing" means removing or hiding a bad smell. In many cases, unpleasant odors may be caused by bacteria that produce off-flavors, and killing the bacteria may have a deodorizing effect. The compositions described herein can release any suitable amount of ClO2The gas to deodorize items stored within the package, such as food products, which may be, for example, agricultural products. For example, one film may incorporate at least 2 parts per million (ppm) ClO2Into the interior volume of the package. Typically, at least 10ppm ClO2The release of gas is sufficient to sterilize the produce. If the package is sealed, the concentration of chlorine dioxide may increase over time as additional chlorine dioxide is released. ClO required for effective deodorization of articles stored in a package2The amount of gas will depend in part on the nature of the article. Further, exposing the article to ClO2The time of the gas will affect the ClO2The ability of the gas to deodorize the article. In some embodiments, the release is fixedAmount of ClO2Gas duration sufficient to expose the article to ClO for at least 2ppm2The gas to deodorize the article. For example, ClO can be released to produce at least 10ppm. hours2Gas, or at least 20ppm. hour of ClO2Chlorine dioxide in an amount of gas to deodorize the article.
As used herein, "disinfection" means reducing the number of viable bacteria. To determine whether an item (e.g., a food product, which may be an agricultural product) is sterilized, it may have been subjected to a sterilization process, such as exposure to ClO2Comparing the item of gas with a control item that has not been subjected to a sterilization treatment to determine whether the bacterial load has been reduced; and, if already reduced, the item will be considered to have been sterilized. Alternatively, the bacterial load of an item, such as agricultural produce, may be compared before and after treatment to determine whether the item has been disinfected. Any suitable amount of ClO may be used2The gas is released into the interior of the package to sterilize the articles disposed within the package. For example, at least 10 parts per million (ppm) of ClO may be added2The gas is released into the interior volume of the package. In some embodiments, at least 50ppm or more of ClO is added2The gas is released into the interior of the package to sterilize the item. ClO required for effective disinfection of agricultural products2The amount of gas will depend in part on the nature of the article, and in addition, the exposure of the article to the ClO2The time of the gas will affect the ClO2The ability of the gas to sterilize the article. In some embodiments, exposure to ultraviolet radiation release is effective to expose the article to ClO for 100ppm2ClO of amount of gas2The gas sterilizes the item. For example, ClO can be released to produce at least 150ppm. hours or more2Gas, or at least 200ppm. hour of ClO2Chlorine dioxide in an amount of gas to sterilize the article.
As used herein, "bactericidal" means free of bacteria or other living organisms. Any suitable amount of ClO can be released2A gas to sterilize articles, such as medical devices, disposed inside the package. For example, at least 200 parts per million (ppm) ClO may be added2The gas is released into the interior volume of the package. In some embodiments, at least 500ppm of ClO is added2The gas is released into the interior of the package to sterilize the items stored within the package. ClO required for effective sterilization of articles2The amount of gas will depend in part on the nature of the article. Further, exposing the article to ClO2The time of the gas will affect the ClO2The ability of the gas to sterilize the article. In some embodiments, an amount of ClO is released2Gas duration sufficient to expose the article to ClO for at least 360ppm2The time of the gas to sterilize the article. For example, the release of an amount of chlorine dioxide can be sustained for a time sufficient to expose the article to ClO for at least 1000ppm2Gas, or at least 2000ppm. hour of ClO2Time of gas to sterilize the article.
As mentioned above, chlorine dioxide can be generated inside the package by the following process: ultraviolet light is directed through the packaging film toward the seal layer of the patch to generate chlorine dioxide gas from chlorite ions in the seal layer of the patch. The ultraviolet light can be directed to the sealing layer of the patch for a sufficient time to produce an effective amount of chlorine dioxide release within the interior space of the sealed package. In some embodiments, the ultraviolet light has a wavelength in the range of about 200nm to 400 nm. In some such embodiments, the ultraviolet light has a wavelength in the range of about 230nm to 320 nm. In some such embodiments, the ultraviolet light has a wavelength in the range of about 240nm to 280 nm. Preferably, the ultraviolet light comprises light having a wavelength of about 254 nm. The ultraviolet light may be broad spectrum light or narrow spectrum light. The source of UV light may be broad or narrow spectrum. In some embodiments, a broad spectrum source is used with a narrow spectrum filter. For example, a filter that allows light having a wavelength of about 254nm may be used.
In some embodiments, the package is exposed to the ultraviolet light for a period of time greater than 10 milliseconds. In some such embodiments, the package is exposed to the ultraviolet light for a period of time greater than 10 seconds. In some such embodiments, the package is exposed to the ultraviolet light for a period of time greater than 10 minutes. The amount of time the package is exposed to the ultraviolet light may depend on the intensity of the UV source, the distance of the UV source, and the desired level of chlorine dioxide.
In some embodiments, the step of exposing the composition to ultraviolet light may be repeated one or more times to generate chlorine dioxide gas.
Once a sufficient amount of chlorine dioxide has been generated and chlorine dioxide has been present for a sufficient amount of time, the package can be exposed to ultraviolet light to accelerate the degradation of the chlorine dioxide. The ultraviolet light applied to accelerate the degradation of chlorine dioxide may be broad spectrum light or narrow spectrum light. The source of UV light may be broad or narrow spectrum. In some embodiments, a broad spectrum source is used with a narrow spectrum filter. For example, a filter that allows light having a wavelength of about 312nm or about 365nm may be used. The ultraviolet light used to accelerate the degradation of chlorine dioxide preferably has a wavelength falling within the range of from about 300nm to about 390nm, regardless of whether the applied light has a broad spectrum or a narrow spectrum. In some embodiments, the ultraviolet light has a wavelength range of about 365nm +/-70 nm. In some preferred embodiments, the ultraviolet light comprises a wavelength of about 312nm or about 365 nm. Preferably, the ultraviolet light comprises a wavelength of about 365 nm.
Although ultraviolet light having a wavelength falling within the range of from about 300nm to about 390nm will accelerate the degradation of chlorine dioxide, it will also generate chlorine dioxide from chlorite ions. Thus, a substantial portion of the ultraviolet light having a wavelength in the range of from about 300nm to about 390nm is preferably blocked from reaching the sealing layer of the patch containing chlorite ions. This can be done if the patch comprises a support that is opaque to ultraviolet light and if the ultraviolet light is directed to the wrapper from the side opposite to the side to which the patch is fixed. In this way, the opaque support layer of the patch will be exposed to ultraviolet light, and the opaque support layer will prevent a significant amount of ultraviolet light from reaching the sealant layer containing chlorite ions. Preferably, the support is opaque to ultraviolet light having a wavelength of about 365nm, opaque to ultraviolet light having a wavelength of about 312nm, or opaque to ultraviolet light having a wavelength in the range of from about 300nm to about 390 nm.
The package can be exposed to ultraviolet light having a wavelength ranging from about 300nm to about 390nm for any suitable amount of time. The amount of time may depend on the concentration of chlorine dioxide in the inner package, the intensity of the ultraviolet light applied, etc. For example, if the initial chlorine dioxide concentration in the package is about 500ppm, the time for exposing the package to ultraviolet light having a wavelength of about 365nm may be longer than if the initial chlorine dioxide concentration is 10ppm.
Preferably, the chlorine dioxide concentration is reduced to less than 0.5ppm prior to opening the package. In some embodiments, the chlorine dioxide concentration in the package is reduced to less than 0.5ppm in about 24 hours after the contents of the package are sterilized by chlorine dioxide. In some embodiments, the chlorine dioxide concentration in the package is reduced to less than 0.5ppm in about 12 hours after the items in the package are sterilized by chlorine dioxide.
In some embodiments, after sterilizing the contents of the package with chlorine dioxide, the chlorine dioxide concentration in the package is reduced to less than 0.5ppm in about 4 hours to 6 hours. Such embodiments are somewhat comparable to the cycle time required for sterilization by autoclaving.
In the drawings, various embodiments of patches, packaging films, wrappers, and methods are illustrated.
Referring now to fig. 1, a schematic cross-sectional view of a
The
Referring now to fig. 2, there is shown a schematic plan view of a sheet 150 from which patch 100 may be formed. The
Patch 150 may be secured to a surface of a packaging film that may be used to form a wrapper.
Referring now to fig. 3, a schematic plan view of the
Referring now to fig. 4, a schematic cross-sectional view of the
Although the packaging film shown in fig. 4 comprises three layers, it is to be understood that a suitable packaging film may have only a single layer or any suitable number of layers, provided that the film is transparent to ultraviolet light and is substantially impermeable to chlorine dioxide.
The second
Referring now to fig. 5, a schematic cross-sectional view of
The first 200 and second 299 packaging films are transparent to ultraviolet light and substantially impermeable to chlorine dioxide.
The item 400 is disposed in the interior space 302 of the
Referring now to fig. 6A, a schematic side view of
After a sufficient amount of time to complete the desired action of chlorine dioxide (e.g., deodorizing, disinfecting, or sterilizing), the
Once the chlorine dioxide level has reached a sufficiently low level (e.g., less than 0.5ppm chlorine dioxide) within the
It is to be understood that this invention is not limited to the particular methodology, protocols, materials, and reagents described, as these may vary. It is also to be understood that the terminology used herein is for the purpose of describing particular embodiments only, and is not intended to limit the scope of the present invention.
The term "comprising" and its variants, when present in the description and claims, is not to be taken in a limiting sense. Such terms are to be understood to imply the inclusion of a stated step or element or group of steps or elements but not the exclusion of any other step or element or group of steps or elements. "consisting of … …" is meant to include and be limited by what follows the phrase "consisting of … …". Thus, the phrase "consisting of … …" indicates that the listed elements are required or mandatory, and that no other elements may be present. "consisting essentially of … …" is intended to include any elements listed after the phrase and is limited to other elements that do not interfere with or contribute to the activity or effect described in this disclosure for the listed elements. Thus, the phrase "consisting essentially of … …" indicates that the listed elements are required or mandatory, but that other elements are optional and may or may not be present depending on whether they substantially affect the activity or effect of the listed elements.
The terms "preferred" and "preferably" refer to embodiments of the disclosure that may provide certain benefits under certain circumstances. However, other embodiments may be preferred, under the same or other circumstances. Furthermore, the recitation of one or more preferred embodiments does not imply that other embodiments are not useful, and is not intended to exclude other embodiments from the scope of the disclosure.
As used herein, "a" and "an" are used interchangeably with "the", "at least one" and "one or more". Thus, for example, a particle core comprising "a" binder can be understood to mean that the particle core includes "one or more" binders. Similarly, a coating comprising "a" porogen may be understood to mean that the composition includes "one or more" porogens.
As used herein, the term "or" is generally employed in its ordinary sense including "and/or" unless the context clearly dictates otherwise.
The term "and/or" means one or all of the listed elements or a combination of any two or more of the listed elements (e.g., preventing and/or treating affliction means preventing, treating, or both preventing and treating affliction).
Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. All publications and patents specifically mentioned herein are incorporated by reference for all purposes.
The following examples are provided for illustrative purposes only and are not intended to limit the scope of the present invention in any way. Indeed, various modifications of the invention in addition to those shown and described herein will become apparent to those skilled in the art from the foregoing description and following examples and fall within the scope of the appended claims.
Examples of the invention
Example 1
In this illustrative example, it is shown that a patch having chlorine dioxide in a seal layer may be secured to an interior surface of a packaging film used to form a package, and that chlorine dioxide may be generated from chlorite ions in the seal layer upon application of ultraviolet light.
Heat seal coating formulation containing chlorite ions
For the desired level of ClO2 release, the heat seal coating formulation needs to incorporate sufficient sodium chlorite while maintaining a stable dispersion. Table 1 provides examples of heat seal coating formulations that meet the objectives. Dow HYPODTM8503 (polyolefin copolymer dispersion) is suitable as a substrate for thermal coating formulations. Keltrol AP acts as a viscosity modifier that thickens the coating to the desired level. Surfynol 107L may be used as an antifoaming agent. Formulations were prepared as indicated in table 1 below.
Table 1: heat seal coating formulation containing chlorite ions
For example, a 3 gallon batch of the heat seal coating formulation described in table 1 above was prepared as follows. 3.6mL of Surfynol 107L was mixed to 4.99kg of Dow HYPODTM8503, 1.72kg of deionized water was added thereto. The resulting mixture was mixed for 5 minutes.
A master batch of 0.25% Keltrol AP was first produced in water by mixing 7.5g of Keltrol AP in 3kg of deionized water for 1-2 hours with a high shear mixer. Mixing the resulting water-based masterbatch to Surfynol 107L/Dow HYPODTM8503 and slowly add 1.54kg of Headline 3875 while mixing. The resulting composition was mixed for 15 minutes to produce a dispersion.
The dispersion was kept stable for at least one day. Prior to use, the dispersion was mixed with a high shear mixer for at least 5 min.
Pressure sensitive adhesive composition containing chlorite ion
Pressure sensitive adhesive compositions were prepared as indicated in table 2 below.
Table 2: pressure sensitive adhesive composition containing chlorite ion
A pressure sensitive adhesive composition containing chlorite ions was prepared as follows. Defoaming agent (107L) was mixed with pressure sensitive adhesive (PS-7860) using a magnetic stir bar. The sodium chlorite solution was slowly added to the stirred solution along with deionized water. Stirring was continued for 15min to thoroughly mix.
Heat-seal coating or PSA on TYVEK
The aqueous heat seal coating or PSA formulation can be applied to TYVEK or other nonwoven using a direct gravure coating process followed by heat curing/drying. As an example, we coated TYVEK (grade: 1073B) with a heat seal coating containing chlorite ions (dry coating weight of 5-10 lbs/ream) using a direct gravure coater (Faustel Tech. center, Milwaukee, Wis.) at a drying temperature of 100 feet/min and 150 ° F (using a 60 feet long oven). As an example, we coated TYVEK with the pressure sensitive adhesive formulation using calendering (drawdown).
Alternatively, the coating may be applied using a flexographic or air knife coater or any other suitable process. For example, the coating may be applied via a Meyer bar, offset printing (offset), or reverse gravure coating process, dipping, spraying, or the like.
Manufacture of packages with "self-sterilising" patches
The resulting "self-sterilizing" heat-seal patch is applied to a packaging film formed into a bag. These packaging films contain one layer of Biaxially Oriented Polyamide (BOPA) and a multi-layer Polyethylene (PE) base layer. The PE base layer serves as a heat seal layer for forming the pouch. These patches are applied to the PE layer.
Characterization of packages with' self-sterilizing patches
For all experiments, the bags were 8 inches by 10 inches in size (BOPA/PE) and contained 2 suicide patches (6cm diameter) sealed inside the wrapper on one side. The patches were made of TYVEK1073B coated with the heat seal formulation described above. The two patches had coating weights of 7-8 lbs/ream and 4-5 lbs/ream, respectively.
The bags were moistened by incubation in a "tropical jungle" chamber (40 ℃ C.; 80% RH) for 1 hour. Alternatively, the bags can be moistened by spraying water over the patch using a spray and incubating for one hour. The bags may also be moistened by, for example, applying water vapor for 30 seconds, applying a wet cloth for 1 minute, applying a humidity control patch (BOVEDA) for 1 hour, or the like.
The amount of chlorine dioxide generated after exposure to ultraviolet light having a wavelength of 254nm (UV254) was determined. FIG. 7 shows that nearly 400ppm ClO can be generated in the package after 60-90 seconds of UV exposure2. FIG. 8 indicates the ClO inside the package2The concentration reached essentially zero within 24 hours.
Sterilization with' self-sterilizing Patch
Biological indicators (each 10)6Geobacillus stearothermophilus spore composition (# SCS-06; Contai industries, Crosstex industries, Ohio)) was placed in the suicide bag described above. The package was sealed and after UV activation (60 seconds) ClO was produced2. The sterilization of the Biological Indicator (BI) is evaluated after incubation in the package for various times to determine the minimum time required for sterilization thereof. BI was assessed by incubation in media (Crosstex GMBCP-100; incubation temperature: 55 ℃) which changes color in response to bacterial growth. If the incubated BI has been sterilized, no color change is observed. Table 3 shows sterilization of BI within 2.5 hours of incubation in the package.
For internally released ClO2Gas packaging barrier
The suicide bag contains internally released ClO as characterized below2The ability of the cell to perform. Will seal and initiate the release of ClO2(concentration: 400ppm in 200 mL) of a suicide bag together with ClO2Gas detector (Honeywell GasAl)ert Extreme; detection range: 0.01-1ppm) are stored together in a second rigid container (hermetically closed; 3000mL volume), the detector can detect any ClO leaking from the suicide bag2And record it. The detector can record a minimum reading of 0.01ppm ClO2. After 48 hours of storage, the detector did not detect ClO2This indicates any ClO that may escape2Is less than in the volume of the container<0.01ppm。
Table 3: self-sterilization of BI in bag
Example 2
In this illustrative example, it was demonstrated that exposure of a suicide bag (SS bag) as described in example 1 to ultraviolet light having a 365nm wavelength (UV365) can accelerate the degradation of chlorine dioxide, so these bags can be opened safely significantly faster than without exposure to UV 365.
As indicated in example 1, the bags were 8 inches by 10 inches in size (BOPA/PE) for all experiments and contained 2 suicide patches (6mm diameter) sealed within the wrapper on one side. The two patches had coating weights of 7-8 lbs/ream and 4-5 lbs/ream, respectively. The bags were moistened by incubation in a "tropical jungle" chamber (40 ℃ C.; 80% RH) for 1 hour.
ClO in package2Half reaction period (No 365nm light used)
In characterization of ClO in SS bag2In the half-reaction period experiments described in example 1, ClO in activated SS bags was measured at different time points (3 replicates per time point), as described in example 12Concentration (see fig. 8). The SS pouches were activated by exposing the patch-containing side of the pouches to 254nm UV light. As indicated in example 1 above, FIG. 8 indicates that ClO was released due to2Naturally decompose over time to form ClO in the package2The concentration reached essentially zero within 24 hours. Note that ClO is 4 hours lower2Is about 100ppm.
In addition toIn one experiment, the patch-free side of the pouches was exposed to UV365 for different durations (1-10 min; 3 replicates per duration) at t-3 hours after UV activation similar to above at t-0 hours. ClO in the bag at t-4 hours was measured2And (4) concentration.
Fig. 9 shows that the SS bags exposed to UV365 for 10min at t-4 hours had 10ppm ClO, quite different from 100ppm of the bags not exposed to UV3652A gas.
It should be noted that UV365 may also be produced by NaClO, albeit in smaller quantities than UV2542Production of ClO2A gas. However, the design of the package prevents UV365 from reactivating ClO2Release, since TYVEK patch is opaque to UV light and contains NaClO2The heat seal coating of (a) is not accessible to UV light from the other side. When the package was subjected to UV365 from the opposite side (i.e., the same side as UV254), the ClO remaining in the bag was found to be2The concentration was about 5ppm higher than when the package was subjected to UV365 from the front side (i.e., as opposed to UV254) (data not shown).