Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B27/00—Layered products comprising a layer of synthetic resin
  • B32B27/30—Layered products comprising a layer of synthetic resin comprising vinyl (co)polymers; comprising acrylic (co)polymers
  • B32B27/306—Layered products comprising a layer of synthetic resin comprising vinyl (co)polymers; comprising acrylic (co)polymers comprising vinyl acetate or vinyl alcohol (co)polymers
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C48/00—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor
  • B29C48/022—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor characterised by the choice of material
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C48/00—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor
  • B29C48/03—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor characterised by the shape of the extruded material at extrusion
  • B29C48/07—Flat, e.g. panels
  • B29C48/08—Flat, e.g. panels flexible, e.g. films
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C48/00—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor
  • B29C48/16—Articles comprising two or more components, e.g. co-extruded layers
  • B29C48/18—Articles comprising two or more components, e.g. co-extruded layers the components being layers
  • B29C48/21—Articles comprising two or more components, e.g. co-extruded layers the components being layers the layers being joined at their surfaces
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B27/00—Layered products comprising a layer of synthetic resin
  • B32B27/06—Layered products comprising a layer of synthetic resin as the main or only constituent of a layer, which is next to another layer of the same or of a different material
  • B32B27/08—Layered products comprising a layer of synthetic resin as the main or only constituent of a layer, which is next to another layer of the same or of a different material of synthetic resin
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B27/00—Layered products comprising a layer of synthetic resin
  • B32B27/18—Layered products comprising a layer of synthetic resin characterised by the use of special additives
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B27/00—Layered products comprising a layer of synthetic resin
  • B32B27/32—Layered products comprising a layer of synthetic resin comprising polyolefins
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B7/00—Layered products characterised by the relation between layers; Layered products characterised by the relative orientation of features between layers, or by the relative values of a measurable parameter between layers, i.e. products comprising layers having different physical, chemical or physicochemical properties; Layered products characterised by the interconnection of layers
  • B32B7/04—Interconnection of layers
  • B32B7/12—Interconnection of layers using interposed adhesives or interposed materials with bonding properties
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C48/00—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor
  • B29C48/16—Articles comprising two or more components, e.g. co-extruded layers
  • B29C48/18—Articles comprising two or more components, e.g. co-extruded layers the components being layers
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29K—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR MOULDS, REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
  • B29K2023/00—Use of polyalkenes or derivatives thereof as moulding material
  • B29K2023/04—Polymers of ethylene
  • B29K2023/08—Copolymers of ethylene
  • B29K2023/086—EVOH, i.e. ethylene vinyl alcohol copolymer
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29L—INDEXING SCHEME ASSOCIATED WITH SUBCLASS B29C, RELATING TO PARTICULAR ARTICLES
  • B29L2031/00—Other particular articles
  • B29L2031/712—Containers; Packaging elements or accessories, Packages
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B2250/00—Layers arrangement
  • B32B2250/05—5 or more layers
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B2250/00—Layers arrangement
  • B32B2250/24—All layers being polymeric
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B2307/00—Properties of the layers or laminate
  • B32B2307/30—Properties of the layers or laminate having particular thermal properties
  • B32B2307/31—Heat sealable
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B2307/00—Properties of the layers or laminate
  • B32B2307/70—Other properties
  • B32B2307/724—Permeability to gases, adsorption
  • B32B2307/7242—Non-permeable
  • B32B2307/7244—Oxygen barrier
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B2307/00—Properties of the layers or laminate
  • B32B2307/70—Other properties
  • B32B2307/724—Permeability to gases, adsorption
  • B32B2307/7242—Non-permeable
  • B32B2307/7246—Water vapor barrier
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B2307/00—Properties of the layers or laminate
  • B32B2307/70—Other properties
  • B32B2307/724—Permeability to gases, adsorption
  • B32B2307/7242—Non-permeable
  • B32B2307/7248—Odour barrier
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B2439/00—Containers; Receptacles
  • B32B2439/40—Closed containers
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B2439/00—Containers; Receptacles
  • B32B2439/40—Closed containers
  • B32B2439/46—Bags
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B2439/00—Containers; Receptacles
  • B32B2439/70—Food packaging

Definitions

• This disclosure relates generally to container filling systems and methods and more particularly relates to systems and methods for the manufacture, assembly, transport, and filling of the several component used to create a container and the like
• PET-based bottles and containers have been used widely in the beverage industry for packaging carbonated beverages, fruit juices, fruit drinks, and the like.
• PET- and other polymer-based bottles may suffer from insufficient mechanical and/or thermal properties and poor barrier performance properties, allowing oxygen ingress and/or carbon dioxide loss. Flavor scalping by particularly polymer resins may also limit performance of polymer-based packaging.
• barrier laminate packaging structures used for beverage base or component pouches or cartridges may be subjected to temperature extremes during storage or transportation and may be used in a dispenser without proper refrigeration.
• These barrier laminate packaging structures can generally comprise various functional layers to enhance package performance.
• the specific chemical composition of the pouch or bag that contains the beverage base, component, or component concentrate can affect flavor scalping, oxygen permeability, and/or undesirable moisture ingress or egress, which affect the stability and useful life of the pouch or cartridge and its contents.
• a major function of flexible plastic packaging for food is its protection during the distribution cycle between the vendor and the consumer.
• the plastic layer(s) adjacent to the food if not properly designed to yield an adequate barrier to flavor sorption, may absorb food flavor components and alter the flavor experience, thereby reducing product quality for the consumer.
• the food contact layer in a flexible plastic package is often required to be heat sealable so the package can be hermetically sealed to protect the food from exposure to oxygen gas, moisture loss, and absorption of environmental contaminants. Heat sealability and low flavor absorption, however, are often opposing considerations when choosing a thermoplastic material to comprise the food contact layer.
• semi-crystalline polymers may be employed as food contact layers since the crystalline domains create a barrier to diffusion and uptake of flavor components.
• crystalline polymers may be difficult to heat seal due restricted chain mobility across the interface of the plied films. This can be especially true of semi-crystalline, hydrogen-bonded barrier polymers such as polyvinyl alcohol and ethylene-vinyl alcohol copolymers.
• this disclosure describes employing a polymer blending approach or strategy, which has been found to distribute and disperse a heat sealable polyolefin-based resin or resin blend, in an ethylene vinyl alcohol (EVA) copolymer.
• EVA ethylene vinyl alcohol
• the ethylene content of the ethylene vinyl alcohol (EVA) co-polymer can be from about 1 mol% to about 90 mol%; alternatively, from about 10 mol% to about 75 mol%; alternatively, from about 20 mol% to about 60 mol%; or alternatively, from about 24 mol% to about 48 mol%.
• the heat sealing resin can be blended as a minor component at a volume fraction at or below its level of co-continuity (4> mm or ⁇ 0.19 based upon theory, but the minor phase volume fraction could be as high as 50 % or higher) with the primary EVOH matrix.
• phase stability can be generally safeguarded by the addition of a reactive, interfacial compatibilizing polymer to the ethylene-based minor phase resin prior to blending with the primary EVOH matrix. While not being bound to any theory, it is believed the reactive compatiblizing polymer can diffuse to the polyolefin-EVOH interface and react with the hydroxyl functionality of the EVOH resin, thereby stabilizing the phase structure and providing enhanced interfacial strength development during processing and heat sealing as new interfacial area is generated.
• this disclosure provides new heat sealable, barrier laminate packaging structures used for beverage component pouches, bags, or cartridges, including new structures and chemical compositions of the pouch made to contain the beverage base, component, or component concentrate.
• These structures and compositions used for the barrier laminate packaging can provide improved heat sealability while enhancing performance for flavor scalping, oxygen permeability, and/or undesirable moisture ingress or egress. These properties, in turn, affect the stability and useful life of the pouch or cartridge and its contents.
• barrier laminate packaging structures can comprise various functional layers to enhance and ensure package performance.
• the outermost layers of the laminate may possess higher peak melting temperatures than the innermost heat sealing layer.
• Exemplary and somewhat typical embodiments of barrier laminate structures known are illustrated in Table 1.
• PET-Ox inorganic oxide coating on PET (polyethylene
• PE polyethylene-based polymer or copolymer
• BOP A a biaxially -oriented polyamide
• PA a polyamide
• tie an intermediate or "tie” layer, such as anhydride-modified
• polyamide layers generally impart a limited gas barrier function but provide strength a puncture resistance to the structure.
• the EVOH (ethylene vinyl alcohol copolymer) layer generally provides a barrier to oxygen gas ingress
• PE polyethylene-based polymer or copolymer
• PET-Ox organic oxide coating on PET
• U.S. Patent No. 7,678,448 to Hachisuka et al. and assigned on its face to Mitsubishi Plastics, Inc. and U.S. Patent No. 6,902,802 to Kurlan et al. and assigned on its face to E. I. Dupont de Nemours and Company describe various heat sealing resins and non-scalping resins with a low heat sealing initiation temperature.
• barrier laminate structures possess a sealant layer that is heat sealable to itself in a first closure and to itself and/or a dispensing fitment in a second heat sealing operation after filling to form the finished package.
• Most heat sealing layers include polyolefin-based polymers and copolymers.
• Typical examples of polyolefin-based polymers and copolymers include Ziegler-Natta or metallocene-catalyzed polyethylene homopolymers, and alpha-olefin copolymers, ethylene-propylene copolymers, ethylene-acrylic acid and ethylene-methacrylic acid copolymers, and partially neutralized variants thereof.
• sealant polymers for barrier laminate structures are provided in U. S. Patent No. 7,678,448.
• Many of these polyolefin-based sealant layers while being easily heat sealable at low heat seal initiation temperatures and having high heat seal strengths, can be prone to significant uptake of the flavor components in the packaged product. This undesirable uptake of the flavor components in the packaged product is referred to herein as "flavor scalping.”
• flavor scalping The tendency for various flavor components to diffuse into and partition within the sealant polymer matrix leaves the package product deplete of original flavor quality, aroma and taste profiles.
• the present disclosure addresses this issue by the use of a polar barrier polymers specially formulated to provide the requisite resistance to flavor scalping while at the same time providing excellent heat sealability.
• the sealant layer according to this disclosure can be, can comprise, or can be selected from a polar barrier polymer such as a specially formulated EVOH, to afford these functions.
• EVOH copolymers are not known for their heat sealing performance due to their high crystallinity and high peak melting temperatures.
• This disclosure describes the unexpected success in designing specially tailored EVOH copolymers and formulations of specific "balanced" polymer blends to provide the enhanced performance. That is, the particular balanced polymer blends ensure both adequate heat sealing and improved flavor scalping performance.
• this disclosure provides new heat sealable, barrier laminate packaging structures used for beverage component pouches or cartridges, including new structures and chemical compositions of the pouch made to contain the beverage base, component, or component concentrate.
• the various balanced polymer blends, pouches and cartridges, and methods set out in this disclosure can be applied generally and broadly to barrier laminate structures, regardless of their construction. That is, the disclosed polymer blends, pouches and cartridges offer a direct "drop-in" technology for mitigating flavor scalping, without sacrificing the heat sealability of the laminate structure.
• this disclosure provides a laminate packaging structure for beverage component pouches, the structure comprising:
• an innermost heat sealing layer comprising at least one of:
• the laminate packaging structure for beverage component pouches can further comprise:
• the ethylene content of the ethylene vinyl alcohol (EVOH) co-polymer can be from about 1 mol% to about 90 mol%; altematively, from about 10 mol% to about 75 mol%; alternatively, from about 20 mol% to about 60 mol%; or alternatively, from about 24 mol% to about 48 mol%.
• the EVOH and ethylene-based homopolymer or copolymer blend can include a hydroxyl-reactive compatibilizing agent that can connect the EVOH phase with the ethylene copolymer blend-based phase across the interface.
• compatibilizing agents include but are not limited to anhydride-grafted variants of the polyethylene, an epoxy-modified (glycidyl) resin capable of reactively engaging EVOH hydroxyl functionality (e.g. glycidyl methacrylate-modified resins), and/or any resin with a reactive functionality capable of reaction with hydroxyl functionality.
• this disclosure also describes a method of reducing flavor scalping in a barrier laminate packaging structure for beverage component pouches, the method comprising:
• a beverage component pouch having an innermost heat sealing layer comprising at least one of:
• PE polyethylene
• this method of reducing flavor scalping can involve co-extruded a laminate packaging structure used for the beverage pouch, comprising the innermost heat sealing layer as described immediately above, and further comprising:
• At least one optional polymer barrier layer compatible with and adjacent the innermost heat sealing layer at least one optional polymer barrier layer compatible with and adjacent the innermost heat sealing layer;
• an innermost heat sealing layer comprising at least one of:
• Multilayers afford some limits in flavor scalping of molecules that may have varying solubilities and diffusion rates in the first few inner layers of the packaging. For example, certain flavor molecules may be retained by the low solubility in the first (innermost) layer, while other molecules may be soluble in the first (innermost) layer, but not in the second layer.
• this disclosure envisions that the EVOH and ethylene-based homopolymer or copolymer blend with the hydroxyl-reactive compatibilizing agent can connect the EVOH phase with the ethylene copolymer blend-based phase across the interface. While not being bound theory, this generally can achieve the a two-fold purpose: (1) to strengthen the interface so that the blended layer is pervasively integrated and strong; and (2) to provide heat sealable ethylene-copolymer domains at the film surface which can self-interdiffuse to yield improved heat seal strengths, above and beyond that which would be attainable with EVOH alone as a heat sealing layer. Accordingly, this aspect describes why a reactive compatibilizing polymer is generally added to the ethylene-based homopolymer or copolymer blended layer only.
• the reactive polymer were to be added to the EVOH layer, its presence would excessively crosslink the EVOH and render the layer non-heat sealable. Therefore, if the reactive compatibilizing polymer is added to the non-reactive blended ethylene-based homopolymer(s) and/or copolymer(s), the phase is entangled but not crosslinked. It is thought that the interface can become covalently linked when the reactive compatiblizing polymer diffuses to the EVOH interface and reacts with the hydroxyl functionality of EVOH.
• FIG. 1 presents a plot of estimated HSP (Hansen Solubility Parameter) Distance (x-axis) versus the percent (%) loss of specific aroma chemicals (y-axis), for number of flavor molecules and poly olefins. (This plot is adapted from the "The Official Hansen Solubility Parameter Site” at http://hansen-solubility.com/).
• FIG. 2 provides a graphical comparison of various thermal and crystallinity properties for PVOH (poly(vinyl alcohol)) at 0 mol% ethylene content, LDPE (low density polyethylene) at 100 mol% ethylene content, and selected EVOH (ethylene vinyl alcohol) copolymers, in accordance with certain embodiments of this disclosure. Plotted are the glass transition temperatures, peak melting temperatures, and mass-based crystallinity for PVOH, selected EVOH copolymers and LDPE. This analysis provides the balanced sealant heat sealing performance and the flavor scalping performance generally within the range of 40% ⁇ mol% ethylene ⁇ 80%, although this approach is applicable to ethylene mole percentages from 1 mol%
• FIG. 3 compares the Kwei model fit of the subject EVOH co-polymer Tg according to this disclosure, by plotting the calculated EVOH copolymer Tg (°C) versus the actual EVOH copolymer Tg (°C), based on the Kwei Model Parameters of k, 0.999 and p, 17.58.
• the calculated EVOH copolymer Tg, Kwei (°C) is obtained according to the following equation:
• this disclosure provides new compositions, packaging structures, and methods related to heat sealable, barrier laminate packaging that are particularly useful for beverage component pouches, bags, or cartridges.
• New structures and chemical compositions of the pouch made to contain the beverage base, component, or component concentrate are provided, which can provide improved heat sealability while enhancing performance for flavor scalping, oxygen permeability, and/or undesirable moisture ingress or egress. These properties, in turn, affect the stability and useful life of the pouch or cartridge and its contents.
• beverage flavor components have molecular weights ranging from about 100 g/mol to about 250 g/mol.
• Useful flavor components and molecules include a wide range of chemical functional moieties, varying polarities, and chemical and physical properties.
• Many flavor components for carbonated soft drinks are citrus-based.
• Table 2 for orange juice, which illustrates the relationship between flavor component molecular weight and molecular size, tabulated as molar volume in the table.
• a comprehensive analysis of citrus aroma/flavor compounds is given in Hognadottir et al , "Identification of Aroma Active Compounds in Orange Essence Oil Using Gas Chromatography-Olfactory and Gas
• Solubility parameter-based approaches such as the Hildebrand Solubility Parameter methodology can be employed to describe or characterize the sealant polymer-flavor component interaction, or the interaction between any two molecules or substances for which Hildebrand Solubility Parameters can be determined.
• the relative ranking of how specific molecular forces of interaction (dispersion (D), polar (P), and hydrogen bonding (H)) between the sealant polymer and a given flavor component interact can be used to predict flavor scalping performance of this particular sealant layer-flavor component combination.
• solubility parameters such as the Hildebrand solubility parameter ⁇ are expressed as the square root of the cohesive energy density of a substance, which is the molar heat of vaporization of a substance E divided by its molar volume V according to the following relationship (Eq. 2):
• the units of the solubility parameter are (energy/volume) . Because the units of energy density are equivalent with those of pressure, one usually encounters solubility parameters expresses in units of (pressure) 1 ⁇ 2 , such as MPa 1/2 .
• Hansen Solubility parameters are expressed in identical units.
• the Hansen Solubility Parameter (HSP) approach assumes the total cohesive energy of the material is equal to the heat of vaporization. Furthermore, the heat of vaporization is divided into contributions from atomic dispersion forces 6 D , permanent dipole forces ⁇ ⁇ , and hydrogen bonding forces 5H. These contributions are summed as independent vectors to yield the overall Hansen Solubility Parameter: (3).
• the solubility parameter approach provides a quantitative method of assessing the "likeness" between substances when the differences between the squares of the respective solubility parameters are considered.
• HSP theory provides the solubility parameter "distance" R a .
• R a the solubility parameter between Hansen parameters for any
• each molecule or polymer has three Hansen parameters, each having the units (MPa 1/2 ), as follows:
• ⁇ (MPa ) is the energy from dipolar intermolecular force between molecules
• the "distance" (R a ) (also in MPa ) between Hansen parameters for any combination of two molecules, such as a polymer and flavor molecule, is calculated according to the following equations. In these equations, the ⁇ parameters are indicated for molecule 1 and molecule 2.
• the factor of 4 leading the first term in the radical is an empirical addition to the equations to achieve a better data fit.
• the HSP distance R a yields a relative assessment of the molecular compatibility between two substances related to the total relative contributions of their molecular interactions.
• the distance R a has increased significance when compared to the experimentally determined solubility sphere radius Ro of a substance. According to HSP theory, miscibility is indicated when the ratio R Ro ⁇ 1, this ratio being referred to as the RED Number in HSP analysis.
• Table 3 in this disclosure demonstrates an HSP analysis for flavor scalping using the HSP approach to provide a ranking of potential sealant layer compositions, in terms of their projected flavor scalping performance.
• five flavor marker compounds were examined, specifically: ⁇ i-limonene, eugenol, octanal, nonanal, and decanal. These five flavor molecules were used to assess the HSP screening distance (R a ) for particular sealant polymer- flavor compound combinations.
• the first five rows summarize the component and total Hansen Solubility Parameters for five selected flavor marker compounds common to many commercial flavored beverage products.
• the second five rows reveal the HSP distances between these five flavor marker compounds.
• the data show that the maximum distance among the five compounds occurs between d-limonene and eugenol, illustrated below.
• the minimum HSP distance pair of nonanal and decanal can be explained by the realization that octanal, nonanal, and decanal represent a series of C8 through CIO homologs alkyl aldehydes with each successive aldehyde in the sequence differing by only a single methylene unit.
• the Table 3 data further illustrates the difficulty in selecting a single polymer food contact layer to mitigate scalping for all flavor compounds.
• polymers having large HSP distances from non-polar compounds like d-limonene may limit uptake of d-limonene, but they may not be shifted substantially far enough away from mid-range polar compounds such the aldehydes or from flavor compounds that engage in hydrogen bonding interactions.
• the polymer can be designed or selected so as to maximize the distances along the three molecular interaction axes, that is, along each of the dispersion, polar, and hydrogen bonding axes, the value of the polymer HSP may be shifted far enough away from the flavor component with the largest HSP value that flavor scalping can be effectively minimized.
• This concept is illustrated, for example, in FIG. 1, and in the calculations comprising Table 4, wherein the
• HSP analysis provided for a screening distance of 6.25 MPa and Aroma Compound Loss of 75.0 % (see FIG. 1).
• PVOH Poly(vinyl alcohol)
• PVP polyvinylpyrrolidone
• cellophane are substantially water-soluble and may swell in the presence of water to such an extent that their use would severely compromise the seal strength in an aqueous beverage component packaging application.
• an EVOH (ethylene vinyl alcohol) copolymer will exhibit heat sealing and flavor scalping behavior intermediate between that of PVOH and low density polyethylene (LDPE).
• the EVOH is formed by hydrolyzing a free-radical polymerized ethylene-vinyl acetate copolymer with similar chain architecture to a LDPE.
• EVOH copolymers are typically specified according to their molar ethylene content, that is, the mole percentage (mol%) of ethylene in the co-polymer.
• Table 5 provides certain EVOH polymer thermal data, which compared PVOH, EVOH and LDPE properties in order to identify the composition range capable of providing good heat sealing performance with low flavor scalping.
• FIG. 2 also provides a graphical comparison of the Table 5 data, showing various thermal and crystallinity properties for PVOH (poly(vinyl alcohol)) at 0 mol% ethylene content, LDPE (low density polyethylene) at 100 mol% ethylene content, and selected EVOH (ethylene vinyl alcohol) copolymers with varying amounts of ethylene content, in accordance with certain aspects of this disclosure. Plotted are the glass transition
• compositions that balance good heating performance and good flavor scalping performance may be realized in the range of ethylene content between about 40 mol% and 80 mol%. See, Table 5 and FIG. 2.
• Commercially-known EVOH co-polymers with the highest ethylene content contain about 48 mol% ethylene. Therefore, it has been discovered that EVOH co-polymers having higher ethylene content that this, and up to about 80 mol%, are suitable for the balanced and improved heating performance and flavor scalping performance. That is, this disclosure provides for heat sealing layer polymers to be, to comprise, or to be selected from an EVOH co-polymer in which about 40 ⁇ mol% ethylene ⁇ about 80%.
• a blend of an ethylene-based heat sealant resins with the EVOH can be provided, which give an effective ethylene mole percentage within the range of from about 1 mol% to about 90 mol%, but generally within the range between about 40 mol% and about 80 mol%, can be utilized.
• the EVOH can be blended with one or more of the following ethylene-based homopolymers and/or copolymers to provide the disclosed blend of an ethylene-based heat sealant resins with the EVOH: LDPE; HDPE; LLDPE; VLDPE; ULDPE; ethylene copolymers with vinyl acetate; ethylene copolymers with methyl-, ethyl-, or butyl-acrylate; ethylene-acid copolymers with acrylic acid, methacrylic acid and partially or completely neutralized ionomers thereof; maleic anhydride-grafted ethylene copolymers; glycidyl methacrylate or epoxy modified ethylene copolymers; or any other ethylene-based copolymer(s) possessing a hydroxyl-reactive functionality, and the like.
• polymer blends such as disclosed immediately above yield the sealant layer compositions that achieve the requisite balance of both good heat sealability properties with low flavor scalping properties, according to the principles set out in this disclosure. That is, this disclosure provides for heat sealing layer polymers to be, to comprise, or to be selected from a blend of an EVOH copolymer and PE (polyethylene) blend in which the total ethylene content in the blend is from about 1 mol% to about 90 mol%.
• the EVOH copolymer and PE blend can have a total ethylene content of about 40 ⁇ mol% ethylene ⁇ about 80%. In this composition range, it is also possible to include some PVOH in the blend, if desired.
• this disclosure provides for a laminate packaging structure such as a beverage component pouch having an innermost heat sealing layer comprising at least one of: a) an EVOH (ethylene vinyl alcohol) copolymer having an ethylene content of from about 1 mol% and about 90 mol%; and/or b) an EVOH copolymer and PE (polyethylene) blend having a total ethylene content in the blend of from about 1 mol% and about 90 mol%.
• a laminate packaging structure such as a beverage component pouch having an innermost heat sealing layer comprising at least one of: a) an EVOH (ethylene vinyl alcohol) copolymer having an ethylene content of from about 1 mol% and about 90 mol%; and/or b) an EVOH copolymer and PE (polyethylene) blend having a total ethylene content in the blend of from about 1 mol% and about 90 mol%.
• the EVOH copolymer can have have an ethylene content of from about 1 mol% and about 80 mol% and/or the EVOH copolymer and PE (polyethylene) blend can have a total ethylene content in the blend of from about 1 mol% and about 80 mol%.
• the mol% of ethylene in the EVOH co-polymer or the mol% of ethylene in the EVOH/PE blend can be about 1 mol%, 2 mol%, 3 mol%, 4 mol%, 5 mol%, 6 mol%, 7 mol%, 8 mol%, 9 mol%, 10 mol%, 12 mol%, 15 mol%, 18 mol%, 20 mol%, 25 mol%, 30 mol%, 35 mol%, 40 mol%, 45 mol%, 50 mol%, 55 mol%, 60 mol%, 65 mol%, 70 mol%, 75 mol%, 80 mol%, 85 mol%, or 90 mol%, or any range between any of these mole percentages.
• a laminate packaging structure such as a beverage component pouch having an innermost heat sealing layer comprising an EVOH copolymer and PE (polyethylene) blend having a total ethylene content in the blend of from about 1 mol% and about 90 mol%, from about 10 mol% and about 90 mol%, from about 20 mol% and about 85 mol%, from about 30 mol% and about 85 mol%, or from about 40 mol% and about 80 mol%.
• PE polyethylene
• the EVOH copolymer and PE (polyethylene) blend can generally have a total ethylene content in the blend of about 20 mol%, 25 mol%, 30 mol%, 35 mol%, 40 mol%, 45 mol%, 50 mol%, 55 mol%, 60 mol%, 65 mol%, 70 mol%, 75 mol%, or 80 mol%.
• this disclosure provides for a process for heat-sealing two thermoplastics wherein the two thermoplastic surfaces are sealed to one another by the application of heat and pressure, wherein the improvement comprises at least one of the thermoplastics comprises an EVOH (ethylene vinyl alcohol) copolymer having an ethylene content of from about 1 mol% to about 90 mol%; and/or an EVOH copolymer and PE
• EVOH ethylene vinyl alcohol
• polyethylene polyethylene blend in which the total ethylene content in the blend is from about 1 mol% to about 90 mol%.
• the disclosure also provides an article wherein two thermoplastic surfaces have been heat-sealed, wherein at least one of the thermoplastic surfaces comprises an EVOH (ethylene vinyl alcohol) copolymer having an ethylene content of from about 1 mol% to about 90 mol%; and/or an EVOH copolymer and PE (polyethylene) blend in which the total ethylene content in the blend is from about 1 mol% to about 90 mol%.
• EVOH ethylene vinyl alcohol copolymer having an ethylene content of from about 1 mol% to about 90 mol%
• PE polyethylene
• the strategy for the current disclosure can utilize the addition of a polyolefin-based sealant resin as a minor component blended and homogenized with EVOH to provide a sealant layer with improved heat sealing performance.
• This approach has been found to unexpectedly maintain the excellent flavor scalping resistance of EVOH for a wide range of flavor components of varying polarities.
• Prior to this disclosure there have been few attempts to address a potential laminate sealant composition that is both heat sealable and non-flavor scalping. While not bound by theory, this result may be due to the observation that these features are generally mutually exclusive. That is, most polymers that are resistant to flavor scalping are generally quite difficult to heat seal.
• this disclosure is directed generally toward the stabilization of polymer blend morphologies in immiscible or partially miscible polymer blends comprising the food contact and heat sealing layer of the laminate structure.
• the following summary of various aspects of the disclosure pertain to the composition and blending sequence for the sealant layer formulation with respect to the following general guidelines.
• composition for the heat sealant-food contact layer of the laminate structure may comprise as a first component an EVOH copolymer with an ethylene content in the range of from 1 mole percent to 80 mole percent, or alternatively, in the range of from 1 mole percent to 90 mole percent, admixed with at least one polyolefin polymer or copolymer composition, containing at least one interfacial compatibilizing agent.
• the EVOH copolymer may comprise from at least 10 volume percent to at most 99 volume percent of the heat sealant-food contact layer.
• the polyolefin composition may comprise one or more polymers from the following list: high density polyethylene (HDPE), linear low density (LLDPE), very-low density (VLDPE) or ultra-low density (ULDPE) polyethylene copolymers catalyzed by a various heterogeneous and homogeneous transition metal coordination catalyst technologies; high-pressure, free radical polymerized ethylene homopolymers (LDPE); high-pressure, free-radical polymerized copolymers of ethylene with vinyl acetate, acrylates (e.g. methyl-, ethyl-, and/or butyl-acrylates), acid comonomers (e.g. acrylic acid, and methacrylic acid); and partially-neutralized or neutralized ionomers of ethylene-acid copolymers; and various blend of the preceding polymers.
• the compatibilizing agent may comprise, may consist essentially of, or may be
• Suitable tie layer adhesives may comprise, may consist essentially of, or may be selected from the group consisting of, but are not limited to, ethylene-vinyl acetate copolymers, ethyl ene-acry late copolymers, ethylene-acid copolymers, and glycidyl methacrylate-modified ethylene copolymers.
• the EVOH and ethylene-based homopolymer or copolymer blend with the hydroxyl- reactive compatibilizing agent can connect the EVOH phase with the ethylene copolymer blend- based phase across the interface.
• This connecting or compatibilizing function strengthens the interface so that the blended layer is pervasively integrated and strong and also provides heat sealable ethylene-copolymer domains at the film surface which can self-interdiffuse to yield improved heat seal strengths.
• the reactive compatibilizing polymer is generally added to the ethylene-based homopolymer or copolymer blended layer only.
• Table 6 summarizes several exemplary blends which illustrate the concept over a range of compositions.
• the list provided in this table by no means is inclusive of all possible embodiments or even most embodiments, but these examples illustrate the salient features of the concept sealant layer composition and formulation strategy.
• EVOH ethylene vinyl alcohol copolymer
• HDPE high density polyethylene
• LLDPE linear low density polyethylene
• met-LLDPE metalized linear low density polyethylene, typically comprising a thin layer of aluminum deposited on the polyethylene surface
• EAA ethylene acrylic acid
• g-MAH maleic anhydride grafted polymer
• an EVOH copolymer comprising an ethylene content in the range of 1 mol% to 90 mol% or more can be blended directly or sequentially with the polyolefin minor phase and reactive compatiblizer, or with a compounded polyolefin masterbatch comprising a polyolefin-based minor component and a reactive (covalently bonded or though relatively strong intermolecular attraction), interfacial compatibilizing polymer to yield a multiphase polymer blend with volume-based compositions of 50.1 % ⁇ ⁇ f> major ⁇ 99.5 % and 0.5 % ⁇ ⁇ f> minor ⁇ 49.9 %.
• composition of the blend also could be equivalently specified in weight percentages base upon using appropriate mass phase densities for each component.
• the volume fraction of the minor phase integrates the minor polyolefin component and the reactive interfacial compatibilizing polymer.
• the addition of the interfacial compatibilizing polymer generally can be added at a mass fraction between 0.01 wt% and 100 wt% of the minor phase polyolefin blend.
• the actual composition of the interfacial compatibilizing polymer generally depends upon its concentration of reactive functionality, its molecular weight and molecular weight distribution, and the intensities of masterbatch and final blend mixing employed, among other variables.
• the polyolefin minor phase of the blend may act as a type of reservoir for storage the interfacial compatibilizing polymer while at the same time limiting its exposure to the EVOH phase in a controlled manner.
• sufficient reactive compatibilizing polymer may be provided to react and bridge the EVOH phase, while anchoring the minor polyolefin phase. Accordingly, too much reactive compatibilizing polymer within the EVOH phase may lead to excessive crosslinking which would impede flow and caulking during the heat sealing process.
• the interfacial compatibilizing polymer desirably can include some measure of reactive functionality that can react with the EVOH hydroxyl functionality.
• Applicable reactive chemical functionalities include such groups as anhydride, epoxy (glycidyl), and the like that are capable of creating a covalent bond across the EVOH- polyolefin minor phase interface.
• these are exemplary chemical functionalities, because it is not necessary that interfacial bonding be covalent, as adequate interface stabilization and strengthening may be achieved by compatibilizing polymers that operate through different specific interactions such as hydrogen bonding, ionic interactions, polar interactions, dispersion forces, and the like.
• polymers can include olefin-vinyl acid copolymers and related ionomers, for example.
• the polyolefin composition may comprise or may be selected from one or more of the following polymers: high density polyethylene (HDPE), linear low density (LLDPE), very -low density (VLDPE) or ultra-low density (ULDPE) polyethylene copolymers catalyzed by a various heterogeneous and homogeneous transition metal
• LDPE high-pressure, free-radical polymerized copolymers of ethylene with vinyl acetate, acrylates (e.g. methyl-, ethyl-, and/or butyl-acrylates), acid comonomers (e.g. acrylic acid, and methacrylic acid); and partially-neutralized or neutralized ionomers of ethylene acid copolymers; and various blend of the preceding polymers.
• LDPE, HDPE, LLDPE, or VLDPE with Ethylene- Acid Copolymer Add EVA or EMA copolymer as interfacial compatibilizers, and
• compatibilizing agent capable of reacting with EVOH hydroxyl functionality.
• Polymer blends are designed using copolymers in which the neighboring units in the copolymer have a lower affinity for each other than the units composing another polymer or copolymer. If the interaction energy between the copolymer units is more positive than for the interactions in the blended polymer, then the overall interaction energy will be lowered and partial miscibility may occur. Specific interactions such as hydrogen bonding may be effectively used in polymer blends to drive interfacial compatibility and partial miscibility between phases. Definitions
• CSD carbonated soft drink
• a polymer "blend” or a blend of polymers and/or co-polymers constitutes an art- recognized class of materials based on the listed polymers. According to the IUPAC
• a polymer blend is a macroscopically homogeneous mixture of two or more different species of polymers.
• Polymer blends have a homogeneous nature and well-defined properties.
• PVOH poly(vinyl alcohol) which has at 0 mol% ethylene content
• LDPE low density polyethylene which has 100 mol% ethylene content
• EVOH is an ethylene vinyl alcohol copolymer, which is nominally a co-polymer of vinyl alcohol and ethylene, and contains an ethylene content greater than 0 mol% and less than 100 mol%.
• compositions and methods are described in terms of “comprising” various components or steps, the compositions and methods can also “consist essentially of or “consist of the various components or steps.
• Applicants reserve the right to proviso out or exclude any individual members of any such group, including any sub-ranges or combinations of sub-ranges within the group, if for any reason Applicants choose to claim less than the full measure of the disclosure, for example, to account for a reference that Applicants are unaware of at the time of the filing of the application.
• Values or ranges may be expressed herein as “about”, from “about” one particular value, and/or to “about” another particular value. When such values or ranges are expressed, other embodiments disclosed include the specific value recited, from the one particular value, and/or to the other particular value. Similarly, when values are expressed as approximations, by use of the antecedent “about,” it will be understood that the particular value forms another embodiment. It will be further understood that there are a number of values disclosed therein, and that each value is also herein disclosed as “about” that particular value in addition to the value itself. In another aspect, use of the term “about” means ⁇ 20% of the stated value, ⁇ 15% of the stated value, ⁇ 10% of the stated value, ⁇ 5% of the stated value, or ⁇ 3% of the stated value.

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• 2016
  • 2016-10-07 JP JP2018517722A patent/JP6843848B2/ja active Active
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  • 2016-10-07 US US15/766,226 patent/US10744749B2/en active Active
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