EP4724657A1 - Matériaux et procédés de modulation d'humidité - Google Patents

Matériaux et procédés de modulation d'humidité

Info

Publication number
EP4724657A1
EP4724657A1 EP24819664.4A EP24819664A EP4724657A1 EP 4724657 A1 EP4724657 A1 EP 4724657A1 EP 24819664 A EP24819664 A EP 24819664A EP 4724657 A1 EP4724657 A1 EP 4724657A1
Authority
EP
European Patent Office
Prior art keywords
cellulose
hygroscopic salt
matrix
carrier
per square
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
EP24819664.4A
Other languages
German (de)
English (en)
Inventor
Peter Lee
Callum Windley
Cameron Bartley
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Bambax Ltd
Original Assignee
Bambax Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from AU2023901833A external-priority patent/AU2023901833A0/en
Application filed by Bambax Ltd filed Critical Bambax Ltd
Publication of EP4724657A1 publication Critical patent/EP4724657A1/fr
Pending legal-status Critical Current

Links

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
    • B32B27/06—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
    • B32B27/10—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 paper or cardboard
    • 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
    • B32B27/36—Layered products comprising a layer of synthetic resin comprising polyesters
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
    • B65D—CONTAINERS FOR STORAGE OR TRANSPORT OF ARTICLES OR MATERIALS, e.g. BAGS, BARRELS, BOTTLES, BOXES, CANS, CARTONS, CRATES, DRUMS, JARS, TANKS, HOPPERS, FORWARDING CONTAINERS; ACCESSORIES, CLOSURES, OR FITTINGS THEREFOR; PACKAGING ELEMENTS; PACKAGES
    • B65D65/00—Wrappers or flexible covers; Packaging materials of special type or form
    • B65D65/38—Packaging materials of special type or form
    • B65D65/42—Applications of coated or impregnated materials
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
    • B65D—CONTAINERS FOR STORAGE OR TRANSPORT OF ARTICLES OR MATERIALS, e.g. BAGS, BARRELS, BOTTLES, BOXES, CANS, CARTONS, CRATES, DRUMS, JARS, TANKS, HOPPERS, FORWARDING CONTAINERS; ACCESSORIES, CLOSURES, OR FITTINGS THEREFOR; PACKAGING ELEMENTS; PACKAGES
    • B65D65/00—Wrappers or flexible covers; Packaging materials of special type or form
    • B65D65/38—Packaging materials of special type or form
    • B65D65/46—Applications of disintegrable, dissolvable or edible materials
    • B65D65/466—Bio- or photodegradable packaging materials
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
    • B65D—CONTAINERS FOR STORAGE OR TRANSPORT OF ARTICLES OR MATERIALS, e.g. BAGS, BARRELS, BOTTLES, BOXES, CANS, CARTONS, CRATES, DRUMS, JARS, TANKS, HOPPERS, FORWARDING CONTAINERS; ACCESSORIES, CLOSURES, OR FITTINGS THEREFOR; PACKAGING ELEMENTS; PACKAGES
    • B65D81/00—Containers, packaging elements, or packages, for contents presenting particular transport or storage problems, or adapted to be used for non-packaging purposes after removal of contents
    • B65D81/24—Adaptations for preventing deterioration or decay of contents; Applications to the container or packaging material of food preservatives, fungicides, pesticides or animal repellants
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
    • C08K3/00—Use of inorganic substances as compounding ingredients
    • C08K3/34—Silicon-containing compounds
    • C08K3/346—Clay
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
    • C08K7/00—Use of ingredients characterised by shape
    • C08K7/02—Fibres or whiskers
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
    • C08L1/00—Compositions of cellulose, modified cellulose or cellulose derivatives
    • C08L1/02—Cellulose; Modified cellulose
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
    • C09D101/00—Coating compositions based on cellulose, modified cellulose, or cellulose derivatives
    • C09D101/02—Cellulose; Modified cellulose
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
    • C09D189/00—Coating compositions based on proteins; Coating compositions based on derivatives thereof
    • D—TEXTILES; PAPER
    • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
    • D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
    • D21H17/00—Non-fibrous material added to the pulp, characterised by its constitution; Paper-impregnating material characterised by its constitution
    • D21H17/63—Inorganic compounds
    • D—TEXTILES; PAPER
    • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
    • D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
    • D21H17/00—Non-fibrous material added to the pulp, characterised by its constitution; Paper-impregnating material characterised by its constitution
    • D21H17/63—Inorganic compounds
    • D21H17/66—Salts, e.g. alums
    • D—TEXTILES; PAPER
    • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
    • D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
    • D21H19/00—Coated paper; Coating material
    • D21H19/10—Coatings without pigments
    • D21H19/12—Coatings without pigments applied as a solution using water as the only solvent, e.g. in the presence of acid or alkaline compounds
    • D—TEXTILES; PAPER
    • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
    • D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
    • D21H19/00—Coated paper; Coating material
    • D21H19/10—Coatings without pigments
    • D21H19/14—Coatings without pigments applied in a form other than the aqueous solution defined in group D21H19/12
    • D21H19/18—Coatings without pigments applied in a form other than the aqueous solution defined in group D21H19/12 comprising waxes
    • D—TEXTILES; PAPER
    • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
    • D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
    • D21H19/00—Coated paper; Coating material
    • D21H19/36—Coatings with pigments
    • D21H19/38—Coatings with pigments characterised by the pigments
    • D21H19/40—Coatings with pigments characterised by the pigments siliceous, e.g. clays
    • D—TEXTILES; PAPER
    • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
    • D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
    • D21H19/00—Coated paper; Coating material
    • D21H19/36—Coatings with pigments
    • D21H19/44—Coatings with pigments characterised by the other ingredients, e.g. the binder or dispersing agent
    • D21H19/52—Cellulose; Derivatives thereof
    • D—TEXTILES; PAPER
    • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
    • D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
    • D21H19/00—Coated paper; Coating material
    • D21H19/80—Paper comprising more than one coating
    • D21H19/82—Paper comprising more than one coating superposed
    • D21H19/826—Paper comprising more than one coating superposed two superposed coatings, the first applied being pigmented and the second applied being non-pigmented
    • D—TEXTILES; PAPER
    • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
    • D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
    • D21H19/00—Coated paper; Coating material
    • D21H19/80—Paper comprising more than one coating
    • D21H19/82—Paper comprising more than one coating superposed
    • D21H19/828—Paper comprising more than one coating superposed two superposed coatings, the first applied being non-pigmented and the second applied being pigmented
    • D—TEXTILES; PAPER
    • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
    • D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
    • D21H27/00—Special paper not otherwise provided for, e.g. made by multi-step processes
    • D21H27/10—Packing paper
    • 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
    • B32B2250/02—2 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
    • B32B2255/00—Coating on the layer surface
    • B32B2255/12—Coating on the layer surface on paper layer
    • 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
    • B32B2255/00—Coating on the layer surface
    • B32B2255/20—Inorganic coating
    • 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
    • B32B2255/00—Coating on the layer surface
    • B32B2255/26—Polymeric coating
    • 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
    • B32B2255/00—Coating on the layer surface
    • B32B2255/28—Multiple coating on one surface
    • 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
    • B32B2307/716—Degradable
    • B32B2307/7163—Biodegradable
    • 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
    • B32B2439/00—Containers; Receptacles
    • B32B2439/70—Food packaging
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
    • C08K3/00—Use of inorganic substances as compounding ingredients
    • C08K3/16—Halogen-containing compounds
    • C08K2003/162—Calcium, strontium or barium halides, e.g. calcium, strontium or barium chloride
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
    • C08K2201/00—Specific properties of additives
    • C08K2201/013—Additives applied to the surface of polymers or polymer particles

Definitions

  • the present invention relates generally to moisture vapour transmission modulators and/or humidity control materials, and more particularly but not necessarily exclusively, to compositions for decreasing the moisture vapour transmission rate and/or humidity control and their method of use.
  • the composition of the invention may be applied to a material.
  • Such materials may be used in packaging goods prone to spoilage such as food.
  • Such materials may be used to reduce or prevent degradation of or damage to packaged electronics, pharmaceuticals, and dry products such as paper (so as to prevent curl in copy paper).
  • Such materials may be used to form packaging that may otherwise be weakened by the action of liquids such as water.
  • a high relative humidity environment can facilitate the growth of microorganisms such as bacteria and mould. Even under cold conditions, a high relative humidity presents problems as moisture can result in unwanted ice crystals being formed on a product. In both cases, where the product is food, accelerated spoilage will usually occur.
  • product packaging that provides a moisture barrier, such as sealed metal packaging, hard plastic packaging, or soft plastic packaging.
  • product packaging is a disposable item and will typically not decompose. Whilst the recycling of some of these forms of packaging may reduce the environmental impact of the use of that packaging, inevitably some of the material will enter landfill and that waste compounds over time. Even relatively cheap disposable materials such as polyethylene that are used to provide soft plastic packaging are not impervious to moisture.
  • MVTR moisture vapor transmission rate
  • the packaging allows for moisture vapour to pass through and that the product within the packaging is not sealed within the packaging.
  • An example of this is when the product itself is hygroscopic and can release water vapour upon increasing temperatures, e.g. tomatoes.
  • the desiccant and as well as the packing material need to be carefully selected based on the properties of the product. It is therefore desirable to be able to modulate the moisture barrier properties of a packaging product, depending on the product to be packaged.
  • Another approach to reducing the impact of environmental moisture on packaged products, which is often used in combination with the use of a packaging material that provides some degree of a moisture barrier, is to include a dessicant material within the packaging.
  • the dessicant will typically compete with the product for absorbing moisture and reduce spoilage.
  • Existing desiccants have limited capacity for absorbing water before the desiccant is saturated, and once saturated further absorption of water is not possible.
  • Existing desiccants are provided in the form of tablets, sachets, and dry powders.
  • a common example in the art of this is silica gel in the form of spherical beads packaged into a sachet which is placed into a package so it can absorb moisture that enters the package.
  • Desiccants in such forms can be accidentally ingested or can be aerosolised upon handling which presents a health risk, that varies depending on the nature of the desiccant.
  • Other more effective desiccants such as calcium chloride become liquid at high humidities and can cause damage.
  • the invention provides a material (such as a packaging material, fabric or building material) including a matrix of fibres, the matrix including at least one (such as two of the following, such as three of the following) of the following: i. a hygroscopic salt which is adsorbed onto the surface of the fibres, the hygroscopic salt being water soluble; ii. a phyllosilicate mineral; and iii. a cellulosic particle which can be entrained within the matrix.
  • a material such as a packaging material, fabric or building material
  • the matrix including at least one (such as two of the following, such as three of the following) of the following: i. a hygroscopic salt which is adsorbed onto the surface of the fibres, the hygroscopic salt being water soluble; ii. a phyllosilicate mineral; and iii. a cellulosic particle which can be entrained within the matrix.
  • the cation of the hygroscopic salt is selected from calcium, magnesium, aluminium, potassium, sodium, zinc, and lithium, and combinations thereof.
  • the cellulosic particle is selected from the group consisting of: a micro-fibrillated cellulose, microcrystalline cellulose, and nano-structured cellulose, and combinations thereof.
  • the material may also include a water insoluble (or poorly soluble) hygroscopic salt.
  • An example of an insoluble hygroscopic salt which may be used in the present invention is calcium sulfate (hemihydrate and/or dihydrate, preferably hemihydrate).
  • the water insoluble (or poorly soluble) hygroscopic salt may be entrained within the matrix of fibres.
  • the invention relates to a matrix of fibres (such as may be found in a packaging material, fabric or building material) that includes a hygroscopic salt adsorbed to the surface of the fibres , the hygroscopic salt being water soluble (preferably wherein the cation of the hygroscopic salt is selected from calcium, magnesium, aluminium, potassium, sodium, zinc, and lithium, and combinations thereof), and the material (such as a packaging material, fabric or building material) further includes at least one of: i. a phyllosilicate mineral; and ii.
  • a cellulosic particle which can be entrained within the matrix (preferably wherein the cellulosic particle is selected from the group consisting of: a micro-fibri Hated cellulose, microcrystalline cellulose, and nano-structured cellulose, and combinations thereof).
  • the invention relates to a matrix of fibres (such as may be found in a packaging material, fabric or building material) that includes a hygroscopic salt adsorbed to the surface of the fibres, the hygroscopic salt being water soluble (preferably wherein the cation of the hygroscopic salt is selected from calcium, magnesium, aluminium, potassium, sodium, zinc, and lithium, and combinations thereof) and the material (such as a packaging material or building material) further includes each of: i. a phyllosilicate mineral; and ii.
  • a cellulosic particle which can be entrained within the matrix (preferably wherein the cellulosic particle is selected from the group consisting of: a micro-fibri Hated cellulose, microcrystalline cellulose, and nano-structured cellulose, and combinations thereof).
  • a hygroscopic salt that is water soluble such as having a cation selected from calcium, magnesium, aluminium, potassium, sodium, zinc, and lithium, and combinations thereof
  • a phyllosilicate mineral applied to a matrix of fibres provides a decreased moisture vapour transmission rate compared with the same material that lacks the phyllosilicate mineral.
  • a cellulosic particle selected from the group consisting of: a micro- fibrillated cellulose, microcrystalline cellulose, and nano-structured cellulose, and combinations thereof
  • a cellulosic particle selected from the group consisting of: a micro- fibrillated cellulose, microcrystalline cellulose, and nano-structured cellulose, and combinations thereof
  • applied to a matrix of fibres provides a decreased moisture vapour transmission rate compared with the same matrix that lacks the particle.
  • any two or more - preferably all three - of the hygroscopic salt, phyllosilicate mineral, and cellulosic particle applied to a material so that the hygroscopic salt is adsorbed to the matrix of fibres provides a decreased moisture vapour transmission rate compared with the same matrix without that combination.
  • the use of any two or more, or all three of the components provides a synergistic decrease in the moisture vapour transmission rate compared with the same matrix without that combination in a manner that could not have been contemplated based merely on an additive effect.
  • the hygroscopic salt functions to adsorb water, while the phyllosilicate mineral and cellulosic particle not only decrease the moisture transmission rate themselves but synergistically assist with dispersing the hygroscopic salt across the matrix.
  • the material (such as a packaging material, fabric or building material) of the invention may be further provided as a composite material, such as further including a layer of polymer, such as biodegradable polymer. It will be appreciated that such a composite material may be referred to as having a sandwich construction.
  • the material (such as a packaging material, fabric or building material) of the present invention may form part of a composite material together with other layers used in the packaging industry such as printed layers, compacted layers, etc.
  • the invention provides a coating system for applying to a material including a matrix of fibres to decrease moisture vapour transmission across said material, the coating system including at least two of the following compositions (such as each of the following components): a composition including: a hygroscopic salt which is water soluble (preferably wherein the cation of the hygroscopic salt is selected from calcium, magnesium, aluminium, potassium, sodium, zinc, and lithium, and combinations thereof); and a first carrier; a composition including: a phyllosilicate mineral; and a second carrier; and a composition including: a cellulosic particle which can be entrained within the matrix (preferably selected from the group consisting of: a micro-fibri Hated cellulose, microcrystalline cellulose, and nanostructured cellulose, and combinations thereof); and a third carrier.
  • the composition may also include a water insoluble (or poorly soluble) hygroscopic salt.
  • a water insoluble hygroscopic salt which may be used in the present invention is calcium sulfate (hemihydrate and/or dihydrate, preferably hemihydrate).
  • the water insoluble (or poorly soluble) hygroscopic salt may be entrained within the matrix of fibres.
  • the coating system may also include a polymer (such as a biodegradable polymer) and a fourth carrier.
  • a polymer such as a biodegradable polymer
  • the first carrier, second carrier, third carrier, and fourth carrier may each be the same or different and may be selected from any carrier suitable for dispersing the hygroscopic salt, the phyllosilicate mineral, the cellulosic particle, or the polymer (respectively).
  • the first carrier, the second carrier, the third carrier, and the fourth carrier are independently selected from an aqueous carrier, such as water.
  • the invention provides a method of treating a material including a matrix of fibres to decrease moisture vapour transmission across said material, the method including the steps of: i. providing a material including a matrix of fibres; ii. applying a first composition to the material, the composition including a first carrier and at least one of: a. a hygroscopic salt which is water soluble (preferably having a cation selected from calcium, magnesium, aluminium, potassium, sodium, zinc, and lithium, and combinations thereof); b. a phyllosilicate mineral; and c.
  • a cellulosic particle which can be entrained within the matrix preferably selected from the group consisting of: a micro-fibrillated cellulose, microcrystalline cellulose, and nanostructured cellulose, and combinations thereof; iii. removing at least a portion of the first carrier from the material.
  • the method may also include a step of applying a water insoluble (or poorly soluble) hygroscopic salt.
  • a water insoluble hygroscopic salt which may be used in the present invention is calcium sulfate (hemihydrate and/or dihydrate, preferably hemihydrate).
  • the water insoluble (or poorly soluble) hygroscopic salt may be entrained within the matrix of fibres.
  • the method of the third aspect will typically coat at least a portion of the material with the hygroscopic salt, phyllosilicate material, and/or particle.
  • at least a portion of the hygroscopic salt will typically be adsorbed to at least a portion of the matrix of fibres of the material.
  • at least a portion of the hygroscopic salt will be adsorbed to: at least a portion of the matrix of fibres of the material; and at least a portion of the particle where the particle is used.
  • the method of the third aspect may include one or more additional coating step(s)).
  • the or each additional coating step(s) may independently include the steps of: i. applying a second composition to the material to which the first composition has been applied, the composition including a second carrier and at least one of: a. a polymer (such as a biodegradable polymer and/or recyclable polymer); b. a hygroscopic salt (preferably having a cation selected from calcium, magnesium, aluminium, potassium, sodium, zinc, and lithium, and combinations thereof); c. a phyllosilicate mineral; and d.
  • a cellulosic particle which can be entrained within the matrix preferably selected from the group consisting of: a micro-fibrillated cellulose, microcrystalline cellulose, and nanostructured cellulose, and combinations thereof; ii. removing at least a portion of the second carrier from the material.
  • the additional coating step(s) may be undertaken iteratively, any number of times, so as to provide a composite material that may include a plurality of layers.
  • the additional coating step may be undertaken once, twice, three times, four times, or five times.
  • a material coated in a traditional polymer coating may only be able to decrease the moisture transmission by a rate X when the polymer coating is provided at a coverage of Y gsm.
  • the material may only need less than Y gsm coverage of the polymer to achieve the same (or better) MVTR X.
  • a layer including a biodegradable polymer is preferably provided last in the iterative coating steps so that the biodegradable polymer is provided at an extremity of the composite material, rather than being interposed (sandwiched) between the outer extremity layers.
  • the biodegradable polymer By positioning the biodegradable polymer at an extremity it may be allowed to contact a packaged product such as food, for example. When used in a package, such an extremity may be internal to the package.
  • a biodegradable polymer may have a thickness of the order of less than 50 microns, such as less than 20 microns, such as about 5 to 10 microns.
  • the invention provides a package being formed, at least in part, from a packaging material, the packaging material including a matrix of fibres, the matrix including at least one (such as two of the following, such as three of the following) of the following: i. a hygroscopic salt which is adsorbed onto the surface of the fibres, the hygroscopic salt being water soluble (preferably the cation of the salt is selected from calcium, magnesium, aluminium, potassium, sodium, zinc, and lithium, and combinations thereof); ii. a phyllosilicate mineral; and iii. a cellulosic particle which can be entrained within the matrix (preferably the particle being selected from the group consisting of: a micro-fibri Hated cellulose, microcrystalline cellulose, and nano-structured cellulose, and combinations thereof).
  • the package may also include a water insoluble (or poorly soluble) hygroscopic salt.
  • a water insoluble hygroscopic salt which may be used in the present invention is calcium sulfate (hemihydrate and/or dihydrate, preferably hemihydrate).
  • the water insoluble (or poorly soluble) hygroscopic salt may be entrained within the matrix of fibres.
  • the package of the fourth aspect is recyclable and/or biodegradable.
  • the package (and packaging material from which it is made) of the fourth aspect may provide a number of advantages.
  • the package forms an enclosure so that the contents of the package can be sealed from the environment external of the package to the contents.
  • the packaging material will provide a decreased moisture vapour transmission rate compared with the same material that lacks the hygroscopic salt; phyllosilicate mineral; and cellulosic particle.
  • this function provides the contents of the enclosed package will retain a substantially constant moisture level over a period of time. Where that contents is a product prone to spoilage, such as food, the shelf-life of the product may be increased.
  • the environment external of the package to the contents will have a higher relative humidity than the environment internal of the package.
  • the environment external of the package to the contents will have a lower relative humidity than the environment internal of the package.
  • the relative humidity of the environment external of the package to the contents will fluctuate (such as through a diurnal cycle or warming and cooling) between a higher relative humidity and a lower relative humidity compared with the environment internal of the package.
  • it will generally be an advantage to decrease the moisture vapour transmission rate through a packaging material so as to retain the qualities of the contents of the package in a condition similar to those when first enclosed in the package.
  • the packaging material provides superior mechanical properties when relatively dry, and inferior mechanical properties if it becomes wet or at least wetter.
  • Such wetting may occur through a number of mechanisms: such as a single incident of being contacted with a liquid such that the liquid wicks through the material; or such as through fluctuating temperature and/or relative humidity conditions that gradually expose the material to wetting conditions.
  • being able to reduce the exposure of the material to moisture would lead to the material retaining the superior mechanical properties for longer.
  • the present invention provides a packaging material that provides a decreased moisture vapour transmission rate compared with the same material that lacks the hygroscopic salt; phyllosilicate mineral; and/or cellulosic particle, which in turn will typically lead to a reduced exposure of the material to moisture.
  • the use of the hygroscopic salt; phyllosilicate mineral; and/or cellulosic particle provides a type of modified atmosphere package, namely a type of packaging system in which the atmospheric composition inside the package is altered from the normal air composition to extend the shelf life of perishable products. In this case the modification is to relative humidity.
  • Two examples of packaging that benefits mechanically from the present invention are detailed below.
  • the mechanical properties of such cardboard will be superior when it is dry compared with when it is wetted.
  • the rate of transmission of environmental moisture through the cardboard material will be decreased and hence the superior mechanical properties will be sustained for a greater period of time than in the absence of the hygroscopic salt; phyllosilicate mineral; and/or cellulosic particle.
  • Cardboard packaging in particular (but also many other forms of packaging to which the present invention is suited) is typically over-engineered so as to account for the assumed loss of mechanical strength as a result of exposure to moisture over time.
  • Another advantage of reducing the rate of transmission of environmental moisture through the cardboard material using the present invention is that the cardboard packaging may be designed more efficiently since it does not need to be over-engineered to the same extent.
  • the material is a laminated cellulosic material used to package liquids, such as marketed by the international company Tetra Pak®
  • Tetra Pak® it is a recognised problem that over time the core cellulosic material becomes increasingly more exposed to moisture from the liquid contents of the package and/or the external environment.
  • the mechanical properties of the cellulosic material are weakened which manifests itself with bulging of the package - namely deformation of the generally planar surfaces towards having a rounded form.
  • the product to be packaged may be substantially dry, partly wet, or otherwise, and may be provided at any temperature.
  • some frozen products are provided packaged in laminated cellulosic material such as laminated cardboard packaging, one example of which is ice cream. Variations in storage temperature of such frozen products, such as during transport, can lead to moisture in the packaging material undergoing a freeze/thaw action which in turn can rapidly degrade the structure of the cellulosic material relied on for the packaging's structure.
  • moisture barrier materials such as polyethylene, polyacrylates, or waxes provide a moisture resistive layer provided by a matrix of those hydrophobic materials.
  • the strength of that barrier will generally be proportional to the thickness of the layer and the hydrophobicity of the matrix material. Once the layer is penetrated, or if the layer does not otherwise fully cover the material, then the material will be exposed to moisture. Where the material is capable of wicking moisture, such a weakness in the layer will inevitably lead to the ingress of moisture. While that technology is well understood and numerous polymers and waxes have been used, those coated materials are typically not biodegradable or recyclable.
  • the present invention differs from other previous approaches to modifying the water permeability of a material.
  • the previous approaches seek to create a barrier layer at the surface of the paper, typically by the technique of dispersion coating which is inherently prone to imperfections imposed by the irregular surface profile of paper on a microscopic scale.
  • WO2021224881 discloses the application of a glyceride and/or a fatty acid salt to a cellulosic/polymeric material to make it hydrophobic and/or lipophilic.
  • WO2021105231 discloses the use of a composite material having multiple layers of water impermeable polymers, most of which are non-biodegradable and would typically mean that the coated product is neither recyclable nor biodegradable.
  • the technology in WO2021105231 uses (meth)acrylate polymers to reduce water permeability.
  • the application of the hygroscopic salt; phyllosilicate mineral; and/or cellulosic particle to the material in the present invention provides a function that is different to the resistive function attempted by conventional moisture barrier materials (such as polyethylene, polyacrylates, or waxes).
  • conventional moisture barrier materials such as polyethylene, polyacrylates, or waxes.
  • the hygroscopic salt; phyllosilicate mineral; and/or cellulosic particle has a capacity (or threshold) to interact with moisture beyond which the hygroscopic salt; phyllosilicate mineral; and/or cellulosic particle will effectively become saturated and no longer inhibit moisture vapour transmission to or across the material. Below such a capacity (or threshold) the moisture vapour transmission will be inhibited and it is believed that adding more hygroscopic salt; phyllosilicate mineral; and/or cellulosic particle will lead to greater inhibition of moisture vapour transmission.
  • the present invention may more broadly relate to a material including a matrix of fibres, the matrix having at least one of the following: a) a first substance having water adsorption qualities, the substance being adsorbed to the surface of the fibres, and b) a second substance that inhibits moisture transmission, and c) a dispersive substance which aids in dispersing the first substance within the fibre matrix.
  • the second substance may inhibit moisture transmission, and aid in dispersing the first substance within the fibre matrix.
  • the present invention may relate to a method of applying the first substance and/or the second substance and/or the dispersive substant to the material.
  • Figure 1 shows an example of the water holding capacity per coating weight of compositions according to the invention
  • Figure 2 shows an example of the water holding efficiency of coatings with microfi bri I lated cellulose, and both microfi bri 11 ated cellulose and nanocrystalline cellulose, with varying calcium chloride content.
  • the present invention is predicated in part on the realisation that the properties (such as moisture vapor transmission rate) of the matrix of fibres may be modulated by the presence of a hygroscopic salt adsorbed to the surface of the fibres.
  • a hygroscopic salt refers to the ability of the hygroscopic salt to absorb water from air.
  • a hygroscopic salt may be applied to the surface of the fibres in a carrier, such as an aqueous carrier, such as in water.
  • the hygroscopic salt is water soluble. After application of the salt as a solution in a carrier, the subsequent removal of the carrier will leave behind the hygroscopic salt.
  • Such a salt may be provided as a hydrate, although it is believed that a form of the hygroscopic salt that is in less than a fully hydrated state is preferred, such as a partially hydrated form, or an anhydrous form.
  • salts are hygroscopic to different degrees.
  • the degree of hygroscopicity of the hygroscopic salt may be considered to be a function of the cation and the anion.
  • Preferred cations are calcium, magnesium, aluminium, potassium, sodium, zinc, and lithium.
  • Preferred anions are chloride, sulphate, carbonate, and nitrate. All combinations of these cations and anions that are hygroscopic and water soluble are contemplated for use in the present invention.
  • different salts are water soluble to different degrees.
  • the degree of water solubility of the hygroscopic salt may be considered to be a function of the cation and the anion.
  • Preferred cations are calcium, magnesium, aluminium, potassium, sodium, zinc, and lithium.
  • Preferred anions are chloride, sulphate, carbonate, and nitrate. All combinations of these cations and anions that are hygroscopic and water soluble are contemplated for use in the present invention.
  • Some preferred salts of the invention are calcium chloride, magnesium chloride lithium chloride, zinc chloride, and aluminium chloride.
  • the most preferred salts of the invention are calcium chloride, magnesium chloride, aluminium sulphate, and calcium nitrate. Of these, calcium chloride is considered to be the most preferred.
  • the invention contemplates the use of either single hygroscopic water soluble salts, or combinations of different hygroscopic water soluble salts.
  • Calcium chloride is deliquescent (becomes liquid after adsorbing high amounts of moisture). In situations of exposure to environments with moderate humidity, calcium chloride can absorb excess moisture, potentially helping to keep the material (such as paper fibres) dry and strong. In particular, by reducing the moisture content of the surrounding air, calcium chloride can prevent the paper fibres from swelling, thereby maintaining their mechanical integrity.
  • non-deliquescent hygroscopic salts such as potassium carbonate and sodium carbonate.
  • the present invention is particularly effective in reducing moisture transmission across a material due to the following factors shared by these particular hygroscopic salts: i) the salts are soluble in carriers, such as aqueous solvents (such as the preferred carrier water) making them easy to use commercially and easier to recycle and/or biodegrade; ii) the salts are hygroscopic, and in some cases are deliquescent salts.
  • the salts form extensive ionic layers adsorbed to the fibres; iii) the salts disperse efficiently across the material (such as the preferred cellulosic material); iv) several of the hygroscopic salts (such as calcium chloride and magnesium chloride) are generally regarded as safe (GRAS) for use in food packaging in particular.
  • GRAS safe
  • the hygroscopic salt is lithium chloride.
  • Lithium chloride is highly soluble in water and is hygroscopic. Lithium chloride has an affinity for cellulose surfaces which makes it suitable for cellulose modification processes.
  • lithium (Li + ) has a relatively small ionic radius, and it does not typically form extensive ionic layers of adsorbed water on cellulose fibres compared to divalent or trivalent cations like calcium (Ca 2+ ) or aluminium (Al 3+ ).
  • the hygroscopic salt is zinc chloride.
  • Zinc chloride is soluble in water and is hygroscopic.
  • Zinc chloride can be used in the modification of cellulose fibres due to its ability to form complexes with cellulose, thereby enhancing its properties such as strength and moisture resistance.
  • Zinc chloride can be used in the production of food packaging materials such as films, coatings, and liners.
  • the hygroscopic salt is aluminium chloride. Aluminium chloride is soluble in water and is hygroscopic. It can modify cellulose surfaces and enhance its properties.
  • the hygroscopic salt is calcium chloride.
  • Calcium chloride is soluble in water and is hygroscopic. Calcium chloride is classified as Generally Recognized as Safe (GRAS) by the FDA when used in accordance with good manufacturing practices (GMP) and within specified limits. Calcium chloride is approved for direct addition to food and is considered safe for use in various food products.
  • GRAS Generally Recognized as Safe
  • the phyllosilicate that may be used in the present invention is a sheet silicate mineral, or a combination of different phyllosilicates.
  • suitable phyllosilicates are a serpentine, a clay, or a mica mineral.
  • the phyllosilicate is a clay or a mica mineral.
  • suitable clays include a halloysite, kaolinite (kaolin), a pyrophyllite, talc, illite, smectite (such as a montmorillonite mineral), chlorite, vermiculite, sepiolite, or a palygorskite (attapulgite) mineral.
  • Suitable mica minerals include a biotite, fuchsite, muscovite, phlogopite, lepidolite, margarite, or a glauconite mineral.
  • suitable serpentine minerals are an antigorite, chrysotile, or a lizardite mineral.
  • the phyllosilicate is selected from a kaolinite (such as red kalonite, such as kaolin), talc, illite (such as red illite, or green French clay), or a bentonite (such as red bentonite). Bentonite is particularly useful in the present invention since its availability is widespread, it is relatively inexpensive, and it performs well.
  • the phyllosilicate may be included (such as entrained) within the matrix (such as within pores within the matrix). It is believed that the phyllosilicates are likely to form agglomerations in combination with the hygroscopic water soluble salt (such as calcium chloride) acting as a flocculation agent.
  • the hygroscopic water soluble salt such as calcium chloride acting as a flocculation agent. This working theory is based on the observation that there is an significant increase in the viscosity of a composition of the hygroscopic water soluble salt and the phyllosilicate in solution, compared with a solution of the hygroscopic water soluble salt alone. It is theorised that the phyllosilicates are an agent of agglomeration.
  • the cellulosic particle may be cellulose or a modified cellulose (such as cellulose acetate) and may contain a mixture of cellulose/modified cellulose with other material(s).
  • the cellulosic particle may be derived from any source of material including both naturally occurring and synthetic/semi -synthetic sources (including synthetic biology sources).
  • the cellulosic particle is preferably selected from micro-fibri Hated cellulose, microcrystalline cellulose, and nano-structured cellulose, and combinations thereof. These forms of cellulose may be formed by treating cellulose in a range of different ways, including by applying shear, reactive extrusion, enzyme mediated hydrolysis, mechanical grinding, ultrasonication, steam explosion, and acid hydrolysis.
  • the cellulosic particle can be entrained within the matrix. This ability will generally be related to the size of the pores that may be found in the matrix, such that the size of the cellulosic particle will be smaller than the size of the pores. For example, the size of the cellulosic particle may be less than 0.1 pm, or from 0.1 to 1 pm, or from 0.1 to 20 pm, or from 0.01 to 200 pm, or from 0.1 to 400 pm. While the cellulosic particle of the invention is described with reference that it "can be entrained within the matrix", it may equally be the case that the cellulosic particle of the invention is actually entrained within the matrix where the cellulosic particle and the matrix have been placed in contact with eachother.
  • Such a matrix may be considered to provide pores as the interstitial space between the fibres in the matrix.
  • the average pore size in a sheet of office paper typically ranges from about 10 to 100 micrometres (pm) in diameter. This range can vary depending on the specific type of office paper, its manufacturing process, and the intended use.
  • a flocculating agent where cellulosic particles having a size of less than 1 pm are used, so that the cellulosic particles are retained within the pores.
  • One such flocculating agent that may be used is calcium cations.
  • micro-fi bri Hated cellulose particles and some phyllosilicates such as bentonite
  • have net negative surface charges When calcium ions are brought into contact with such a charged surface, particularly when both are dispersed in a carrier, they are attracted to the negatively charged surfaces of these particles causing them to flocculate.
  • the cellulosic particle may be included (such as entrained) within the matrix of the material (such as within pores within the material) and/or assist with the dispersion of the hygroscopic salt where the components are used in combination.
  • the hygroscopic salt can also adsorb to the surface of the cellulosic particle.
  • the material (which may otherwise be referred to as the substrate), such as the packaging material, fabric, or building material, includes a matrix of fibres, and may be in the form of a membrane, panel, hydrogel, paste, granule, or pellet, for example.
  • the fibres of the material will typically be formed of polymeric material - the polymer being a biological polymer or a synthetic polymer although blends of biological and synthetic polymers are also contemplated.
  • the matrix of fibres of the material will provide a porous structure which can adsorb a hygroscopic salt and/or retain the phyllosilicate or cellulosic particle of the invention.
  • porous structures are all forms of paper, fabric/cloth (e.g. woven, knitted, non-woven, felted, laminated and spun), and porous construction/architectural materials (e.g. plasterboard, ceiling tiles, foam insulation, panels, plaster).
  • a paper with low porosity and high smoothness is desired primarily so that a dispersion coating of a barrier material will bond to the surface to maximise its barrier properties. While the use of such paper in the current invention is contemplated, it is preferred to use paper that does not have a low porosity.
  • the present inventors have discovered that paper suppliers (such as Mondi, Billerud et al.) that are asked to supply higher porosity papers, generally having a reduced smoothness, have been surprised to be asked to supply such paper.
  • the present invention uses unsized, highly porous paper. It is believed that such paper provides enhanced adsorption of the hygroscopic salt, and entrainment of phyllosilicate material and/or cellulosic particle where used.
  • the (paper) material is uncoated highly porous kraft cellulose-fibre material.
  • the polymer is biodegradable. More preferably the polymer is compostable under both industrial and non-industrial conditions.
  • One recognised non-industrial composting standard is ISO 14855-1 (2012).
  • An example of such a biodegradable material is one that may degrade in home composting conditions where temperatures typically do not attain the temperatures found in industrial composting settings.
  • the biodegradable polymer of the invention is configured to undergo substantial biodegradation within 12 months of being exposed to non-industrial composting conditions.
  • the biodegradable composition of the invention is configured to fully biodegrade within 24 months of being exposed to non-industrial composting conditions.
  • the polymer may be selected from:
  • an aliphatic polyester such as: polyglycolide/ polyfglycolic acid) (PGA), polycaprolactone (PCL), polydioxanone (PDO), polylactic acid (PLA) (including poly(L-l actic acid), poly(D-lactic acid), and poly(DL-lactic acid)), poly(lactic-co-glycolic acid) (PLGA), poly(trimethylene carbonate) (PTMC), poly(butylene succinate-co-butylene adipate) (PBSA), poly(al kyl succinates), including: polyethylene succinate) (PES), (polypropylene succinate) (PPS), poly(butylene succinate) (PBS); polyhydroxyalkanoates (PHA), including polyhydroxybutyrate (PHB), polyhydroxyvalerate (PHV), polyhydroxyhexanoate (PHH), polyhydroxyoctanoate (PHO), polyhydroxydecanoate (PHD), polyhydroxy-5-phenylvalerate (PHPV), poly
  • an aromatic polyester such as: poly(butylene adipate-co-terephthalate) (PBAT);
  • a polyamide such as BAK 1095 and BAK 2195 (based on caprolactam, butanediol, and adipic acid);
  • a polyurethane that will typically include a biodegradable portion consisting of a polyester (such as PCL, PLA, and PGA);
  • an agro-polymer such as such as silk, wool, collagen
  • a polysaccharide such as starch, hemicellulose, cellulose, chitin, chitosan, alginic acid, cellophane, pectin, pullulan, or modified forms thereof, for example cellulose acetate;
  • a polypeptide such as gelatin, wheat gluten, casein, whey protein
  • a vinyl alcohol such as polyvinylalcohol or vinyl alcohol precursor such as poly(vinyl acetate).
  • the material is paper.
  • the paper may be composed of blends of natural polymers, such as cellulose, lignin and hemi-cellulose.
  • the substate is a cellulose material such as paper, cardboard, cottonjute, hemp, sisal, or wood.
  • the substate is a cotton membrane, cellulose membrane, or ligninbased membrane.
  • the substate is paper fibres which are comprised of fibrils, microfibrils which in turn contain cellulose polymers.
  • the cellulose containing fibre may be cellulose fibres extracted from a wood source that are used to make an end product such as paper, paperboard or cardboard.
  • the cellulose fibres may be combined to form a pulp and are then processed into the desired end product with the desired weight, i.e., grams per square metre (gsm).
  • the paper weight when the substate is a paper, the paper weight may be between 50 grams per square meter to 300 grams per square meter, such as about 125 gsm.
  • the material may have a heavier weight than paper - such as heavyweight paperboard which may have a weight of 400 to 600 gsm.
  • Such material is commonly used for more robust packaging applications where additional strength and durability are required, such as rigid boxes, high-end product packaging, and displays. Beyond 600 gsm, the material is often referred to as "chipboard” or “greyboard,” and it is primarily used for applications where stiffness and rigidity are essential, such as book covers, binders, and rigid packaging boxes. All of these forms/weights of products are contemplated for use as the material (material) in the present invention.
  • the material is a starch-based material, including certain types of packaging or starch-based films, which may adsorb salts (such as calcium chloride) through hydrogen bonding, leading to increased water adsorbency.
  • adsorb salts such as calcium chloride
  • the material is a hydrogel.
  • Hydrogels are known for their ability to absorb and retain water.
  • the hydrogel may be formed from polymers such as polyvinyl alcohol (PVA), polyacrylamide, or polysaccharides, which can form hydrogen bonds with salts (such as calcium chloride) resulting in increased water adsorbency.
  • PVA polyvinyl alcohol
  • polyacrylamide polyacrylamide
  • polysaccharides which can form hydrogen bonds with salts (such as calcium chloride) resulting in increased water adsorbency.
  • the material is chitosan, derived from chitin, which contains amino and hydroxyl groups that can form hydrogen bonds with salts (such as calcium chloride), resulting in increased water adsorbency.
  • Chitosan is used in various applications, including as a water treatment agent.
  • the material is silica gel and other silica-based materials which may adsorb salts (such as calcium chloride) through hydrogen bonding, leading to increased water adsorbency.
  • Silica surfaces have hydroxyl groups that can interact with salts such as calcium chloride ions.
  • the substate is sintered glass.
  • the material is a clay or an aluminosilicate.
  • the aluminosilicate may be a zeolite.
  • Clays and zeolites have hydrophilic surfaces, which can adsorb salts such as calcium chloride ions through hydrogen bonding, resulting in increased water adsorbency.
  • the material is a phyllosilicate mineral
  • the phyllosilicate mineral will be provided with a hygroscopic salt and/or a cellulosic particle of the invention.
  • the material is carbon.
  • the density of the substate may be approximately 800-1400 kg/m 3 ; such as approximately 900-1300 kg/m 3 ; such as approximately 1000-1300 kg/m 3 .
  • the material is provided in a substantially planar form, such as in the form of a sheet and/or membrane - such as paper or card/cardboard.
  • the substate in a membrane form may between about 1 to about 500 gsm; such as from 1 to 200 gsm, such as from 50 to 300 gsm, such as from 75 to 150 gsm, such as about 125 gsm.
  • the barrier properties of the substate in a membrane form are such that water vapour transmission through the polymeric layer is less than 50 gsm per day at 25 degrees C and 75% relative humidity.
  • the barrier properties of the material may be enhanced through the additional use of a conventional dispersion coating, such as a coating of a polymeric material, such as a wax or polyhydroxyalkanoate material.
  • the present invention may make use of one or more carriers to disperse one or more of the hygroscopic salt, the phyllosilicate mineral, and/or the cellulosic particle.
  • the carrier will preferably be an aqueous carrier, such as water, and will disperse (such as dissolve) the hygroscopic salt, the phyllosilicate mineral, and/or the cellulosic particle so as to form a dispersion in the aqueous carrier (such as solution) that is capable of being applied to the material.
  • the properties of the carrier may be modified to assist with dispersing the hygroscopic salt, the phyllosilicate mineral, and/or the cellulosic particle.
  • the physical and/or chemical nature of the carrier may be adjusted to modulate the solubility or other properties of the hygroscopic salt, the phyllosilicate mineral, and/or the cellulosic particle being carried therein. For instance, it will be appreciated that the size of the cellulosic particles may lead to agglomeration which may or may not be desired.
  • the desired dispersion of the cellulosic may be adjusted to modulate the solubility or other properties of the hygroscopic salt, the phyllosilicate mineral, and/or the cellulosic particle being carried therein.
  • the material of the invention may be provided with one or more additional layers of material.
  • additional layer(s) of material may be provided to the material before or after the hygroscopic salt, the phyllosilicate mineral, and/or the cellulosic particle is provided on the material.
  • An additional layer may be provided as a membrane such that:
  • the membrane provides barrier properties such that water vapour transmission through the additional layer is less than 300 gsm per day at 25 degrees C and 75% relative humidity. It is to be appreciated that lesser water vapour transmission may be desirable and water vapour transmission may be less than any of 250, 200, 150, 100, 50 or 40 gsm per day at 25 degrees C and 75% relative humidity. Without being limiting, it is generally true that the lesser the water vapour transmission rate at 25 degrees C and 75% relative humidity, the greater the barrier properties of the material (such as a packaging material or building material) and the greater the range of water sensitive produce that can be packaged using the packaging material; and/or
  • the membrane provides oxygen transmission barrier properties, such that oxygen transmission through the second layer is less than 400 cm 3 /m 3 per day at 1 atm oxygen, 25 degrees C and 75% relative humidity. It is to be appreciated that lesser oxygen transmission may be desirable and oxygen vapour transmission may be less than any of 300, 250, 200, 150, 100 or 50 cm 3 /m 3 per day at 1 atm oxygen, 25 degrees C and 75% relative humidity. Without being limiting, it is generally true that the lesser the oxygen transmission rate at 1 atm oxygen, 25 degrees C and 75% relative humidity, the greater the barrier properties of the packaging material and the greater the range of oxygen sensitive produce that can be packaged using the packaging material.
  • the or each additional layer may be independently selected from being from 1 to 500 pm in thickness, such as from 1 to 200 pm in thickness, such as from 1 to 50 pm in thickness, such as up to 30 pm in thickness. It is to be appreciated that a range of thicknesses may be suitable, depending on the application, such as the packaging or building application, and the or each additional layer may be about 10 to about 25 pm in thickness or may be about 15 to about 20 pm in thickness.
  • the or each additional layer may be formed of polymeric material - the polymer being a biological polymer or a synthetic polymer although blends of biological and synthetic polymers are also contemplated.
  • the polymer is biodegradable. More preferably the polymer is compostable under both industrial and non-industrial conditions.
  • One recognised non-industrial composting standard is ISO 14855-1 (2012).
  • An example of such a biodegradable material is one that may degrade in home composting conditions where temperatures typically do not attain the temperatures found in industrial composting settings.
  • the biodegradable polymer of the invention is configured to undergo substantial biodegradation within 12 months of being exposed to non-industrial composting conditions.
  • the biodegradable composition of the invention is configured to fully biodegrade within 24 months of being exposed to non-industrial composting conditions.
  • the polymer may be selected from:
  • an aliphatic polyester such as: polyglycolide/ poly(g lycolic acid) (PGA), polycaprolactone (PCL), polydioxanone (PDO), polylactic acid (PLA) (including poly(L-l actic acid), poly(D-lactic acid), and poly(DL-lactic acid)), poly(lactic-co-glycolic acid) (PLGA), poly(tri methylene carbonate) (PTMC), poly(butylene succinate-co-butylene adipate) (PBSA), poly(al kyl succinates), including: polyethylene succinate) (PES), (polypropylene succinate) (PPS), poly(butylene succinate) (PBS); polyhydroxyalkanoates (PHA), including polyhydroxybutyrate (PHB), polyhydroxyvalerate (PHV), polyhydroxyhexanoate (PHH), polyhydroxyoctanoate (PHO), polyhydroxydecanoate (PHD), polyhydroxy-5-phenylvalerate (PHPV
  • an aromatic polyester such as: poly(butylene adipate-co-terephthalate) (PBAT);
  • a polyamide such as BAK 1095 and BAK 2195 (based on caprolactam, butanediol, and adipic acid);
  • a polyurethane that will typically include a biodegradable portion consisting of a polyester (such as PCL, PLA, and PGA);
  • an agro-polymer such as such as silk, wool, collagen
  • a polysaccharide such as starch, hemicellulose, cellulose, chitin, chitosan, alginic acid, cellophane, pectin, pullulan, or modified forms thereof, for example cellulose acetate;
  • a polypeptide such as gelatin, wheat gluten, casein, whey protein
  • a vinyl alcohol such as polyvinylalcohol or vinyl alcohol precursor such as poly(vinyl acetate).
  • the barrier properties of at least one additional layer is such that water vapour transmission through the additional layer is less than 50 gsm per day at 25 degrees C and 75% relative humidity.
  • the hygroscopic salt, phyllosilicate mineral, and/or cellulosic particle (where used) may be applied separately, or together in any combination possible.
  • each of the hygroscopic salt, phyllosilicate mineral, and/or cellulosic particle (where used) will be dispersed (such as dissolved) in one or more carriers (such as an aqueous carrier, such as water) and the dispersion (such as solution) will be applied to the material.
  • carriers such as an aqueous carrier, such as water
  • the dispersion such as solution
  • Most existing technologies for applying surface treatments to paper are suitable to apply the compositions of the present invention. These include, size presses, short and long dwell coaters, slot coaters, spray coaters, etc.
  • the hygroscopic salt of the present invention is provided as a salt of calcium, lithium, zinc, or aluminium.
  • the present invention can overcome any such challenge particularly when the method of application makes use of a pressure gradient to encourage the chloride/carrier onto/into the material.
  • a pressure gradient may be provided by a pressure pulse which could be thought of as a positive pressure gradient.
  • the pressure pulse may be provided by a blade or pressure roll coater (such as a size press) which can form a pressure pulse as the paper passes through the nip between them and a backing roll.
  • a negative pressure gradient such as may be provided by a vacuum to draw the chloride/carrier into the material.
  • each of the hygroscopic salt, phyllosilicate mineral, and cellulosic particle are applied as a mixture in one coating operation.
  • the quantity of the hygroscopic salt (where used) that may be applied to the material may depend on the intended purpose or application of the material so formed. It may be convenient to refer to the amount of the hygroscopic salt (where used) that is applied with reference to its dry weight per unit surface area of the material. For instance, from 1 to 500 gsm may be applied to the material, such as from 1 to 200 gsm, such as from 5 to 100 gsm. The quantity may be applied in a single application step, or a plurality of application steps. The or each application step may apply from 1 to 100 gsm to the material, such as from 1 to 50 gsm, such as from 1 to 25 gsm, such as from 5 to 25 gsm, such as from 10 to 25 gsm.
  • the quantity of the phyllosilicate mineral (where used) that may be applied to the material may depend on the intended purpose or application of the material so formed. It may be convenient to refer to the amount of the phyllosilicate mineral (where used) that is applied with reference to its dry weight per unit surface area of the material. For instance, from 1 to 500 gsm may be applied to the material, such as from 1 to 200 gsm, such as from 1 to 100 gsm, such as from 5 to 100 gsm. The quantity may be applied in a single application step, or a plurality of application steps. The or each application step may apply from 1 to 100 gsm to the material, such as from 1 to 50 gsm, such as from 1 to 25 gsm, such as from 5 to 25 gsm, such as from 10 to 25 gsm.
  • the quantity of the cellulosic particle (where used) that may be applied to the material may depend on the intended purpose or application of the material so formed. It may be convenient to refer to the amount of the cellulosic particle (where used)) that is applied with reference to its dry weight per unit surface area of the material. For instance, from 1 to 500 gsm may be applied to the material, such as from 1 to 200 gsm, such as from 1 to 100 gsm, such as from 5 to 100 gsm. The quantity may be applied in a single application step, or a plurality of application steps. The or each application step may apply from 1 to 100 gsm to the material, such as from 1 to 50 gsm, such as from 1 to 25 gsm, such as from 5 to 25 gsm, such as from 10 to 25 gsm.
  • An application rate of from 1 to 25 gsm, such as from 5 to 25 gsm, such as from 10 to 25 gsm per application step is believed to be particularly beneficial to materials such as cellulose, or modified cellulose, such as paper, card or cardboard having a weight of about 125 gsm.
  • the hygroscopic salt is adsorbed to the surface of the fibres of the matrix of the material.
  • adsorbed refers to the cation bonding to the cellulose.
  • the phyllosilicate mineral, and/or cellulosic particle are retained by a combination of filtration and the flocculating effect of the cation of the hygroscopic salt - which effect is referred to herein as being "entrained" within the matrix.
  • the cellulosic particles and/or phyllosilicates may be considered to be of the same charge as the matrix of fibres wherein the fibres are cellulosic.
  • the presence of the hygroscopic salt, such as calcium chloride (particularly the calcium cations) will provide somewhat of a bridge between the fibres and the cellulosic particles and/or phyllosilicates. It is believed that this mechanism of adsorbency/adherency leads to maximal dispersal of the hygroscopic salt (in particular) across the material and hence maximising pickup of the active ingredients and the consequent maximal reduction in moisture transmission across the material.
  • absorbency involves the substance being drawn into and held within the internal structure of the material such as within pores of the matrix. Absorbance is likely the predominant mechanism for retaining the particulate components of the treatment, particularly in an agglomerated form.
  • the packaging material of the present invention may be used in a myriad of packaging applications where the packaged product or the package itself is susceptible to damage from moisture and/or oxygen. Examples of such packaged products include:
  • Foodstuffs such as powdered milk, coffee, or powdered supplements
  • Examples of food packaging applications include:
  • Rigid packaging such as takeaway coffee cups, containers of chilled or frozen dairy products, and bowls and trays manufactured through pressing or vacuum forming;
  • Rigid packaging such as 3D pulp containers manufactured through traditional pulping methods with thermoformed polymer layer.
  • Paperboard packaging used for liquid foods which can be weakened by prolonged exposure to moisture during distribution and use.
  • Secondary packaging such as corrugated boxes, which can be weakened by prolonged exposure to cyclic humidity during distribution and fail to protect their contents form mechanical damage.
  • the building material of the present invention may be used in a myriad of building applications where it is desirable to reduce the transmission of moisture and/or oxygen from one side of the material to the other side of the material.
  • the material may be used to control humidity within buildings by installing wallboards and/or ceiling tiles treated with the hygroscopic salt, phyllosilicate mineral, and/or cellulosic particle.
  • the addition of one or more of these components could enhance the wallboard's ability to absorb moisture from the surrounding environment. This property might be advantageous in certain applications, such as controlling humidity in indoor spaces during periods of cyclic diurnal humidity..
  • the building material of the present invention may also be used as a sink/source of moisture such that it absorbs moisture under humid conditions and releases moisture under dry conditions so as to modulate the humidity in an environment.
  • Controls Kraft cellulose-fibre material - negative control; and Kraft cellulose-fibre material coated with a polymeric layer of PHA (25 gsm) - positive control
  • Uncoated highly porous kraft cellulose-fibre material (125 gram per square meter) was measured to have a water vapour transmission rate (WVTR) of 3000 g/m 2 /24hr (measured at 25 degrees Celsius and at 75% relative humidity). For this material, this WVTR represents a negative control.
  • a polymeric coating of polyhydroxyalkanoates (25 gram per square meter, 20 micron) was applied directly to a sheet of highly porous kraft cellulose-fibre material (125 gram per square meter) with a compostable adhesive by air atomizing spray nozzle.
  • the adhesive used was sourced from a compostable laminating adhesive sold by Scitech Adhesive Systems as ST6093G HS.
  • Example 1 Kraft cellulose-fibre material coated with bentonite clay (11.67 gsm), calcium chloride (15.83 gsm), and microftbrillated cellulose and bentonite clay (4.31 gsm)
  • a sheet of highly porous kraft cellulose-fibre material (125 gram per square meter) was spray coated directly by air atomizing spray nozzle with a dispersion of bentonite clay which was then dried to provide on a dry weight basis a 1 1.67 grams per square meter coating of bentonite clay.
  • a solution of calcium chloride was then spray coated directly by air atomizing spray nozzle onto the bentonite clay coated material and then dried to provide on a dry weight basis a 15.83 grams per square meter coating of calcium chloride.
  • a dispersion of 6 wt% bentonite clay and 1 .5 wt% microfi bri I lated cellulose was then spray coated directly by air atomizing spray nozzle onto the bentonite clay and calcium chloride coated material and then dried to provide on a dry weight basis a 4.31 grams per square meter coating of bentonite clay and microfi bri I lated cellulose.
  • the average water vapour transmission rate was 1223 g/m 2 / day (measured at 25 degrees Celsius and at 75% relative humidity), a reduction from a water vapour transmission rate of 3000 g/m 2 /24hr (measured at 25 degrees Celsius and at 75% relative humidity) for the uncoated highly porous kraft cellulose-fibre material (125 gram per square meter).
  • Example 2 Kraft cellulose-fibre material coated with bentonite clay (11.67 gsm)
  • a sheet of highly porous kraft cellulose-fibre material (125 gram per square meter) was spray coated directly by air atomizing spray nozzle with a dispersion of bentonite clay which was then dried to provide on a dry weight basis a 1 1.67 grams per square meter coating of bentonite clay.
  • the average water vapour transmission rate was 344 g/m 2 / day (measured at 25 degrees Celsius and at 75% relative humidity), a significant reduction from a water vapour transmission rate of 3000 g/m 2 /24hr (measured at 25 degrees Celsius and at 75% relative humidity) for the uncoated highly porous kraft cellulose-fibre material (125 gram per square meter).
  • Example 3 Kraft cellulose-fibre material coated with microftbrillated cellulose (6.93 gsm)
  • a sheet of highly porous kraft cellulose-fibre material (125 gram per square meter) was spray coated directly by air atomizing spray nozzle with a dispersion of microfibri Hated cellulose which was then dried (the process of spray coating and drying completed three more times) to provide on a dry weight basis a 6.93 grams per square meter coating of microfi bri Hated cellulose.
  • the average water vapour transmission rate was 681 g/m 2 / day (measured at 25 degrees Celsius and at 75% relative humidity), a significant reduction from a water vapour transmission rate of 3000 g/m 2 /24hr (measured at 25 degrees Celsius and at 75% relative humidity) for the uncoated highly porous kraft cellulose-fibre material (125 gram per square meter).
  • Example 4 Kraft cellulose-fibre material coated with microftbrillated cellulose and bentonite clay (12.93 gsm)
  • a sheet of highly porous kraft cellulose-fibre material (125 gram per square meter) was spray coated directly by air atomizing spray nozzle with a dispersion of 1.5 wt% microfibri Hated cellulose and 6 wt% bentonite clay and which was then dried to provide on a dry weight basis a 12.93 grams per square meter coating of microfi bri I lated cellulose and bentonite clay.
  • the average water vapour transmission rate was 868 g/m 2 / day (measured at 25 degrees Celsius and at 75% relative humidity), a significant reduction from a water vapour transmission rate of 3000 g/m 2 /24hr (measured at 25 degrees Celsius and at 75% relative humidity) for the uncoated highly porous kraft cellulose-fibre material (125 gram per square meter).
  • Example 5 Kraft cellulose-fibre material coated with calcium chloride (15.8 gsm)
  • a sheet of highly porous kraft cellulose-fibre material (125 gram per square meter) was spray coated directly by air atomizing spray nozzle with a solution of calcium chloride, which was then dried to provide on a dry weight basis a 15.8 grams per square meter coating of calcium chloride.
  • the coating was applied in a 50 wt% solids solution after dissolving in deionized water.
  • Example 6 Kraft cellulose-fibre material coated with calcium chloride (63.3 gsm)
  • a sheet of highly porous kraft cellulose-fibre material (125 gram per square meter) was spray coated directly by air atomizing spray nozzle with a solution of calcium chloride, which was then dried to provide on a dry weight basis a 63.3 grams per square meter coating of calcium chloride.
  • the coating was applied in a 50 wt% solids solution after dissolving in deionized water.
  • Example 7 Kraft cellulose-fibre material coated with bentonite clay (11.67 gsm), calcium chloride (15.83 gsm), microftbrillated cellulose and bentonite clay (4.31 gsm), and a polymeric layer of PHA
  • a sheet of highly porous kraft cellulose-fibre material (125 gram per square meter) was spray coated directly by air atomizing spray nozzle with a dispersion of bentonite clay which was then dried to provide on a dry weight basis a 1 1.67 grams per square meter coating of bentonite clay.
  • a solution of calcium chloride was then spray coated directly by air atomizing spray nozzle onto the bentonite clay coated material and then dried to provide on a dry weight basis a 15.83 grams per square meter coating of calcium chloride.
  • a dispersion of 6 wt% bentonite clay and 1 .5 wt% microfi bri I lated cellulose was then spray coated directly by air atomizing spray nozzle onto the bentonite clay and calcium chloride coated material and then dried to provide on a dry weight basis a 4.31 grams per square meter coating of bentonite clay and microfi bri I lated cellulose.
  • This example differed from Example 1 in that a polymeric coating of PHA (25 gram per square meter, 20 micron) was then applied directly to the coated material with a compostable adhesive.
  • the adhesive used was sourced from a compostable laminating adhesive sold by Scitech Adhesive Systems as ST6093G HS.
  • the average water vapour transmission rate was 62 g/m 2 / day (measured at 25 degrees Celsius and at 75% relative humidity), a reduction from a water vapour transmission rate of 3000 g/m 2 /24hr (measured at 25 degrees Celsius and at 75% relative humidity) for the uncoated highly porous kraft cellulose-fibre material (125 gram per square meter).
  • the oxygen transmission rate of this packaging material was also measured and the average was calculated as 747 cm 3 /m 2 /24hr.
  • Example 8 Kraft cellulose-fibre material coated with bentonite clay (11.67 gsm), calcium chloride (15.83 gsm), and microftbrillated cellulose (4.31 gsm)
  • a sheet of highly porous kraft cellulose-fibre material (125 gram per square meter) was spray coated directly by air atomizing spray nozzle with a dispersion of bentonite clay which was then dried to provide on a dry weight basis a 1 1.67 grams per square meter coating of bentonite clay.
  • a solution of calcium chloride was then spray coated directly by air atomizing spray nozzle onto the bentonite clay coated material and then dried to provide on a dry weight basis a 15.83 grams per square meter coating of calcium chloride.
  • a dispersion of 1.5 wt% microfibrillated cellulose was then spray coated directly by air atomizing spray nozzle onto the bentonite clay and calcium chloride coated material and then dried (the process of spray coating and drying completed one more time) to provide on a dry weight basis a 4.31 grams per square meter coating of microfibri Hated cellulose.
  • Example 9 Kraft cellulose-fibre material coated with calcium chloride (15.83 gsm), and microftbrillated cellulose and bentonite clay (12.93 gsm)
  • a sheet of highly porous kraft cellulose-fibre material (125 gram per square meter) was spray coated directly by air atomizing spray nozzle with a solution of calcium chloride and then dried to provide on a dry weight basis a 15.83 grams per square meter coating of calcium chloride.
  • a dispersion of 1 .5 wt% microfi bri I lated cellulose and 6 wt% bentonite clay was then spray coated directly by air atomizing spray nozzle onto the calcium chloride coated material and then dried to provide on a dry weight basis a 12.93 grams per square meter coating of microfi bri I lated cellulose.
  • Example 10 Kraft cellulose-fibre material coated with calcium chloride (15.83 gsm), and a polymeric layer of polyhydroxybutyrate (20 gsm)
  • a sheet of highly porous kraft cellulose-fibre material (125 gram per square meter) was spray coated directly by air atomizing spray nozzle with a solution of calcium chloride and then dried to provide on a dry weight basis a 15.83 grams per square meter coating of calcium chloride.
  • Two polymeric coatings of polyhydroxybutyrate (PHB) (applied sequentially, for a total of 20 gram per square meter, 20 micron) were applied directly by air atomizing spray nozzle to the coated material with a compostable adhesive.
  • the adhesive used was sourced from a compostable laminating adhesive sold by Scitech Adhesive Systems as ST6093G HS.
  • the average water vapour transmission rate was 31 g/m 2 / day (measured at 25 degrees Celsius and at 75% relative humidity), a reduction from a water vapour transmission rate of 3000 g/m 2 /24hr (measured at 25 degrees Celsius and at 75% relative humidity) for the uncoated highly porous kraft cellulose-fibre material (125 gram per square meter).
  • the oxygen transmission rate of this packaging material was also measured and the average was calculated as 253 cm 3 /m 2 /24hr.
  • Example 11 Kraft cellulose-ftbre material coated with calcium chloride (15.83 gsm), bentonite clay and microftbrillated cellulose (12.93 gsm), and a polymeric layer of polyhydroxybutyrate (20 gsm)
  • a sheet of highly porous kraft cellulose-fibre material (125 gram per square meter) was spray coated directly by air atomizing spray nozzle with a solution of calcium chloride and then dried to provide on a dry weight basis a 15.83 grams per square meter coating of calcium chloride.
  • a dispersion of 6 wt% bentonite clay and 1.5 wt% microfibri Hated cellulose was then spray coated directly by air atomizing spray nozzle onto the calcium chloride coated material and then dried (the process of spray coating and drying completed three more times) to provide on a dry weight basis a 12.93 grams per square meter coating of bentonite clay and microfi brillated cellulose.
  • a polymeric coating of polyhydroxybutyrate (PHB) (20 gram per square meter, 20 micron) was then applied directly by air atomizing spray nozzle to the coated material with a compostable adhesive.
  • the adhesive used was sourced from a compostable laminating adhesive sold by Scitech Adhesive Systems as ST6093G HS.
  • the average water vapour transmission rate was 33 g/m 2 /24hr (measured at 25 degrees Celsius and at 75% relative humidity), a reduction from a water vapour transmission rate of 3000 g/m 2 /24hr (measured at 25 degrees Celsius and at 75% relative humidity) for the uncoated highly porous kraft cellulose-fibre material (125 gram per square meter).
  • the oxygen transmission rate of this packaging material was also measured and the average was calculated as 287 cm 3 /m 2 /24hr.
  • Example 12 Kraft cellulose-ftbre material coated with insoluble salt / soluble hygroscopic salt (11.5 gsm)
  • reaction products calcium chloride, potassium carbonate and phosphoric acid (85% in water) were brought into contact in that sequence to generate carbon dioxide together with an aqueous solution of tricalcium phosphate and potassium chloride (the reaction products).
  • the reaction products solution was spray coated (with the optional addition of water to provide a low viscosity solution) onto a sheet of highly porous kraft cellulose-fibre material (125 gram per square meter) directly by air atomizing spray nozzle which was then dried to provide on a dry weight basis a 11.5 grams per square meter coating of the reaction products.
  • the average water vapour transmission rate was between 368 g/m 2 / day (measured at 25 degrees Celsius and at 75% relative humidity), a significant reduction from a water vapour transmission rate of 3000 g/m 2 /24hr (measured at 25 degrees Celsius and at 75% relative humidity) for the uncoated highly porous kraft cellulose-fibre material (125 gram per square meter).
  • Example 13 Kraft cellulose-ftbre material coated with SS (11.5 gsm)
  • reaction products calcium chloride, potassium carbonate and phosphoric acid (85% in water) were reacted together to generate carbon dioxide together with an aqueous solution of tricalcium phosphate and potassium chloride (the reaction products).
  • the reaction products solution was spray coated (with the optional addition of water to provide a low viscosity solution) onto a sheet of highly porous kraft cellulose-fibre material (125 gram per square meter) directly by air atomizing spray nozzle which was then dried to provide on a dry weight basis a 1 1 .5 grams per square meter coating of the reaction products.
  • the average water vapour transmission rate was 375 g/m 2 / day (measured at 25 degrees Celsius and at 75% relative humidity), a significant reduction from a water vapour transmission rate of 3000 g/m 2 /24hr (measured at 25 degrees Celsius and at 75% relative humidity) for the uncoated highly porous kraft cellulose-fibre material (125 gram per square meter).
  • Example 14 Kraft cellulose-ftbre material coated with WPI calcium chloride (20 gsm)
  • a sheet of highly porous kraft cellulose-fibre material (125 gram per square meter) was spray coated directly by air atomizing spray nozzle with a solution of whey protein isolate (WPI) / calcium chloride which was then dried to provide on a dry weight basis a 20 grams per square meter coating of WPI calcium chloride.
  • WPI whey protein isolate
  • the average water vapour transmission rate was 593 g/m 2 / day (measured at 25 degrees Celsius and at 75% relative humidity), a significant reduction from a water vapour transmission rate of 3000 g/m 2 /24hr (measured at 25 degrees Celsius and at 75% relative humidity) for the uncoated highly porous kraft cellulose-fibre material (125 gram per square meter).
  • Example 15 Kraft cellulose-ftbre material coated with WPC calcium chloride (20 gsm)
  • a sheet of highly porous kraft cellulose-fibre material (125 gram per square meter) was spray coated directly by air atomizing spray nozzle with a solution of whey protein ceoncentrate (WPC) / calcium chloride which was then dried to provide on a dry weight basis a 20 grams per square meter coating of WPC calcium chloride.
  • WPC whey protein ceoncentrate
  • the average water vapour transmission rate was 518 g/m 2 / day (measured at 25 degrees Celsius and at 75% relative humidity), a significant reduction from a water vapour transmission rate of 3000 g/m 2 /24hr (measured at 25 degrees Celsius and at 75% relative humidity) for the uncoated highly porous kraft cellulose-fibre material (125 gram per square meter).
  • the water vapour transmission test results show that coating with at least one of calcium chloride, MFC, and a phyllosilicate, provides excellent barrier properties against water vapour permeation through the coating.
  • this observed benefit may be due to the negatively charged platelets within the walls of the microfibri Hated cellulose fibres being neutralised by the positively charged cation region within the tetrahedral molecular structure of the phyllosilicate particles. This provided a very good neutral coating, hence why it was anticipated to be the perfect mechanically sound layer to host the salt compound.
  • Example 16 Kraft cellulose-ftbre material coated with microftbrillated cellulose, red bentonite clay, and subjected to a 50 wt% solution of calcium chloride
  • a sheet of highly porous kraft cellulose-fibre material (125 gram per square meter) was spray coated directly by air atomizing spray nozzle with a dispersion of 1.5 wt% microfibrillated cellulose and 7.7 wt% red bentonite clay. Once dry, the coated material was spray coated directly by air atomizing spray nozzle with a 50 wt% solution of calcium chloride in deionized water, and dried. It was found with this example that the average water holding capacity was 1499.7 kg/m 3 (measured at 25 degrees Celsius).
  • Example 17 Kraft cellulose-ftbre material coated with microftbrillated cellulose, red kaolin clay, and subjected to a 50 wt% solution of calcium chloride
  • a sheet of highly porous kraft cellulose-fibre material (125 gram per square meter) was spray coated directly by air atomizing spray nozzle with a dispersion of 1.5 wt% microfibrillated cellulose, and 11 .6 wt% red kaolin clay, and then dried.
  • the coated material was spray coated directly by air atomizing spray nozzle with a 50 wt% solution of calcium chloride in deionized water, and dried. It was found with this example that the average water holding capacity was 1422.5 kg/m 3 (measured at 25 degrees Celsius).
  • Example 18 Kraft cellulose-ftbre material coated with microftbrillated cellulose, talc, and subjected to a 50 wt% solution of calcium chloride
  • a sheet of highly porous kraft cellulose-fibre material (125 gram per square meter) was spray coated directly by air atomizing spray nozzle with a dispersion of 1.5 wt% microfibrillated cellulose and 7.9 wt% talc, and dried.
  • the coated material was spray coated directly with a 50 wt% solution of calcium chloride in deionized water, and dried. It was found with this example that the average water holding capacity was 1493.8 kg/m 3 (measured at 25 degrees Celsius).
  • Example 19 Kraft cellulose-ftbre material coated with microftbrillated cellulose, red illite clay, and subjected to a 50 wt% solution of calcium chloride
  • a sheet of highly porous kraft cellulose-fibre material (125 gram per square meter) was spray coated directly by air atomizing spray nozzle with a dispersion of 1.5 wt% microfibrillated cellulose, and 6.99 wt% red illite clay, and dried.
  • the coated material was spray coated directly by air atomizing spray nozzle with a 50 wt% solution of calcium chloride in deionized water, and dried. It was found with this example that the average water holding capacity was 1622.0 kg/m 3 (measured at 25 degrees Celsius).
  • Example 20 Kraft cellulose-ftbre material coated with microftbrillated cellulose, Ben Red and subjected to a 50 wt% solution of calcium chloride
  • a sheet of highly porous kraft cellulose-fibre material (125 gram per square meter) was spray coated directly by air atomizing spray nozzle with a dispersion of 1.5 wt% microfibrillated cellulose, and 7.7 wt% Ben Red, and dried.
  • the coated material was spray coated directly by air atomizing spray nozzle with a 50 wt% solution of calcium chloride in deionized water, and dried. It was found with this example that the average water holding capacity was 1382.5 kg/m 3 (measured at 25 degrees Celsius).
  • Example 21 Kraft cellulose-ftbre material coated with microftbrillated cellulose, red bentonite clay and subjected to a 40 wt% solution of calcium chloride
  • a sheet of highly porous kraft cellulose-fibre material (125 gram per square meter) was spray coated directly by air atomizing spray nozzle with a dispersion of 1.5 wt% microfibrillated cellulose, and 7.7 wt% red bentonite clay, and dried.
  • the coated material was spray coated directly by air atomizing spray nozzle with a 40 wt% solution of calcium chloride in deionized water, and dried. It was found with this example that the average water holding capacity was 1249.7 kg/m 3 (measured at 25 degrees Celsius).
  • Example 22 Kraft cellulose-ftbre material coated with microftbrillated cellulose, red bentonite clay and subjected to a 45 wt% solution of calcium chloride
  • a sheet of highly porous kraft cellulose-fibre material (125 gram per square meter) was spray coated directly by air atomizing spray nozzle with a dispersion of 1.5 wt% microfibrillated cellulose, and 7.7 wt% red bentonite clay, and dried.
  • the coated material was spray coated directly by air atomizing spray nozzle with a 45 wt% solution of calcium chloride in deionized water, and dried. It was found with this example that the average water holding capacity was 1370.3 kg/m 3 (measured at 25 degrees Celsius).
  • Example 23 Kraft cellulose-fibre material coated with microfibrillated cellulose, red bentonite clay and subjected to a 20 wt% solution of calcium chloride
  • a sheet of highly porous kraft cellulose-fibre material (125 gram per square meter) was spray coated directly by air atomizing spray nozzle with a dispersion of 1.5 wt% microfibrillated cellulose, and 7.7 wt% red bentonite clay, and dried.
  • the coated material was spray coated directly by air atomizing spray nozzle with a 20 wt% solution of calcium chloride in deionized water, and dried. It was found with this example that the average water holding capacity was 1189.5 kg/m 3 (measured at 25 degrees Celsius).
  • Example 24 Kraft cellulose-fibre material coated with microfibrillated cellulose, red bentonite clay and subjected to a 15 wt% solution of calcium chloride
  • a sheet of highly porous kraft cellulose-fibre material (125 gram per square meter) was spray coated directly by air atomizing spray nozzle with a dispersion of 1.5 wt% microfibrillated cellulose, and 7.7 wt% red bentonite clay, and dried.
  • the coated material was spray coated directly by air atomizing spray nozzle with a 15 wt% solution of calcium chloride in deionized water, and dried. It was found with this example that the average water holding capacity was 1152.1 kg/m 3 (measured at 25 degrees Celsius).
  • Example 25 Kraft cellulose-fibre material coated with microfibrillated cellulose, red bentonite clay and subjected to a solution of 45 wt% calcium chloride and 5wt % wt magnesium sulfate
  • a sheet of highly porous kraft cellulose-fibre material (125 gram per square meter) was spray coated directly by air atomizing spray nozzle with a dispersion of 1.5 wt% microfibrillated cellulose, and 7.7 wt% red bentonite clay, and dried.
  • the coated material was spray coated directly by air atomizing spray nozzle with a solution of 45 wt% calcium chloride and 5 wt% magnesium sulfate in deionized water, and dried. It was found with this example that the average water holding capacity was 1231 .7 kg/m 3 (measured at 25 degrees Celsius).
  • Example 26 Kraft cellulose-fibre material coated with microfibrillated cellulose, red bentonite clay and subjected to a solution of 35 wt% calcium chloride and 15 wt% magnesium sulfate
  • a sheet of highly porous kraft cellulose-fibre material (125 gram per square meter) was spray coated directly by air atomizing spray nozzle with a dispersion of 1.5 wt% microfibrillated cellulose and 7.7 wt% red bentonite clay, and dried.
  • the coated material was spray coated directly by air atomizing spray nozzle with a solution of 35 wt% calcium chloride and 15 wt% magnesium sulfate in deionized water, and dried.
  • Example 27 Kraft cellulose-fibre material coated with microfibrillated cellulose, red bentonite clay and subjected to a solution of 25 wt% calcium chloride and 25 wt% magnesium sulfate
  • a sheet of highly porous kraft cellulose-fibre material (125 gram per square meter) was spray coated directly by air atomizing spray nozzle with a dispersion of 1.5 wt% microfibrillated cellulose and 7.7 wt% red bentonite clay, and dried.
  • the coated material was spray coated directly by air atomizing spray nozzle with a solution of 25 wt% calcium chloride and 25% wt magnesium sulfate in deionized water, and dried. It was found with this example that the average water holding capacity was 845.7 kg/m 3 (measured at 25 degrees Celsius).
  • Example 28 Kraft cellulose-fibre material coated with microfibrillated cellulose, red bentonite clay and subjected to a solution of 15 wt% calcium chloride and 35 wt% magnesium sulfate
  • a sheet of highly porous kraft cellulose-fibre material (125 gram per square meter) was spray coated directly by air atomizing spray nozzle with a dispersion of 1.5 wt% microfibrillated cellulose, 7.7 wt% red bentonite clay, and dried.
  • the coated material was spray coated directly by air atomizing spray nozzle with a solution of 15 wt% calcium chloride and 35% wt magnesium sulfate in deionized water, and dried. It was found with this example that the average water holding capacity was 606.2 kg/m 3 (measured at 25 degrees Celsius).
  • Example 29 Kraft cellulose-fibre material coated with microfibrillated cellulose, red bentonite clay and subjected to a solution of 5 wt% calcium chloride and 45 wt% magnesium sulfate
  • a sheet of highly porous kraft cellulose-fibre material (125 gram per square meter) was spray coated directly by air atomizing spray nozzle with a dispersion of 1.5 wt% microfibrillated cellulose and 7.7 wt% red bentonite clay, and dried.
  • the coated material was spray coated directly by air atomizing spray nozzle with a solution of 5 wt% calcium chloride and 45 wt% magnesium sulfate in deionized water, and dried. It was found with this example that the average water holding capacity was 715.0 kg/m 3 (measured at 25 degrees Celsius).
  • Example 30 Kraft cellulose-fibre material coated with microfibrillated cellulose and subjected a calcium chloride treatment
  • the technology may also be said broadly to consist in the parts, elements and features referred to or indicated in the specification of the application, individually or collectively, in any or all combinations of two or more of said parts, elements or features.

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Abstract

La présente invention concerne de manière générale des modulateurs de transmission de vapeur d'humidité et/ou des matériaux de régulation d'humidité, et plus particulièrement, mais pas nécessairement exclusivement, des compositions de diminution de la vitesse de transmission de vapeur d'humidité et/ou de régulation d'humidité et leur procédé d'utilisation. Dans certaines formes, la composition de l'invention peut être appliquée à un matériau. De tels matériaux peuvent être utilisés dans l'emballage de produits susceptibles de se détériorer, tels que des aliments. De tels matériaux peuvent être utilisés pour réduire ou empêcher la dégradation ou l'endommagement de produits électroniques, pharmaceutiques et de produits secs emballés tels que du papier (de façon à empêcher un gondolage du papier reprographique). De tels matériaux peuvent être utilisés pour former un emballage qui pourrait autrement se trouver affaibli par l'action de liquides tels que l'eau.
EP24819664.4A 2023-06-09 2024-06-07 Matériaux et procédés de modulation d'humidité Pending EP4724657A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
AU2023901833A AU2023901833A0 (en) 2023-06-09 A Packaging Substrate
PCT/NZ2024/050065 WO2024253547A1 (fr) 2023-06-09 2024-06-07 Matériaux et procédés de modulation d'humidité

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EP4724657A1 true EP4724657A1 (fr) 2026-04-15

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EP24819664.4A Pending EP4724657A1 (fr) 2023-06-09 2024-06-07 Matériaux et procédés de modulation d'humidité

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EP (1) EP4724657A1 (fr)
KR (1) KR20260021715A (fr)
CN (1) CN121311645A (fr)
WO (1) WO2024253547A1 (fr)

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20190177920A1 (en) * 2017-12-11 2019-06-13 Graphic Packaging International, Llc Pigmented size press and surface size for coated paper and paperboard
CA3129760A1 (fr) * 2019-02-14 2020-08-20 Mitsubishi Paper Mills Limited Papier d'element d'echange d'enthalpie et element d'echange d'enthalpie
WO2021201114A1 (fr) * 2020-03-31 2021-10-07 日本製紙株式会社 Papier comprenant une couche de revêtement transparente contenant des fibres
WO2022208160A1 (fr) * 2021-04-02 2022-10-06 Fiberlean Technologies Limited Compositions de revêtement microfibrillées améliorées, procédés et applicateurs associés
LU500047B1 (en) * 2021-04-16 2022-10-17 Soremartec Sa Packaging material

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KR20260021715A (ko) 2026-02-13
CN121311645A (zh) 2026-01-09
WO2024253547A1 (fr) 2024-12-12

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