Classifications

• • 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
  • 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
  • B65D3/00—Rigid or semi-rigid containers having bodies or peripheral walls of curved or partially-curved cross-section made by winding or bending paper without folding along defined lines
  • B65D3/22—Rigid or semi-rigid containers having bodies or peripheral walls of curved or partially-curved cross-section made by winding or bending paper without folding along defined lines with double walls; with walls incorporating air-chambers; with walls made of laminated material
• • 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
  • D21H19/20—Coatings without pigments applied in a form other than the aqueous solution defined in group D21H19/12 comprising macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds
• • 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
  • D21H19/20—Coatings without pigments applied in a form other than the aqueous solution defined in group D21H19/12 comprising macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds
  • D21H19/22—Polyalkenes, e.g. polystyrene
• • 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
  • D21H21/00—Non-fibrous material added to the pulp, characterised by its function, form or properties; Paper-impregnating or coating material, characterised by its function, form or properties
  • D21H21/14—Non-fibrous material added to the pulp, characterised by its function, form or properties; Paper-impregnating or coating material, characterised by its function, form or properties characterised by function or properties in or on the paper
  • D21H21/16—Sizing or water-repelling agents
• • 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
  • D21H19/24—Coatings without pigments applied in a form other than the aqueous solution defined in group D21H19/12 comprising macromolecular compounds obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T428/00—Stock material or miscellaneous articles
  • Y10T428/24—Structurally defined web or sheet [e.g., overall dimension, etc.]
  • Y10T428/24802—Discontinuous or differential coating, impregnation or bond [e.g., artwork, printing, retouched photograph, etc.]
  • Y10T428/24893—Discontinuous or differential coating, impregnation or bond [e.g., artwork, printing, retouched photograph, etc.] including particulate material
  • Y10T428/24901—Discontinuous or differential coating, impregnation or bond [e.g., artwork, printing, retouched photograph, etc.] including particulate material including coloring matter
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T428/00—Stock material or miscellaneous articles
  • Y10T428/24—Structurally defined web or sheet [e.g., overall dimension, etc.]
  • Y10T428/24942—Structurally defined web or sheet [e.g., overall dimension, etc.] including components having same physical characteristic in differing degree

Definitions

• the present invention relates to a recyclable, preferably repulpable sheet material as defined below and a container, preferably a cup, based essentially on cellulosic material for water containing foodstuff formed of such recyclable sheet material comprising
• a paper board which is coated with a water barrier coating on at least one of its uncoated surfaces having a smoothness of equal or less than 500 ml/min according to Bendtsen ISO 8791-2 or
• a paper board which is coated on at least one of its uncoated surfaces with a first surface coating based on at least one mineral pigment and on at least one polymeric binder, preferably with polar groups, and which on top of the first surface coating having a smoothness of 100 ml/min or less according to
• Bendtsen ISO 8791-2 is coated with a water barrier coating, wherein each of said water barrier coatings being based on at least one polymer having a melting point of at least 120 °C is applied in an amount of providing a COBB value of the water barrier coated paper board of equal or less 8 g/m 2 per 600 sec and a surface energy equal or greater 38 mJ/m 2 at 20 °C (test liquid:water) and 2) optionally a sealable coating covering at least partially in
• the water barrier coating which sealable coating is based on at least one polymer, preferably with polar groups, having a melting point of at least 10 °C below the melting point of the polymer component of the water barrier coating.
• So called fast food restaurants are a major and growing supplier of nutrition.
• the logical concept of fast food restaurants is based on the single use package.
• Single use means that after the consumption of the food, the package of the food is discarded.
• Such packages may consist of both cellulosic material, predominantly in form of fibres, like paper, paper board or other molded fibre items, or plastic materials like polyethylene, polypropylene or polyethylenterephtalate or of a mixture of cellulosic material and plastic material, a waste management based on recycling the material could be difficult, even impossible.
• this waste consists of a mixture of plastic material and cellulosic material typically. In order to recycle this waste, it is necessary to separate the different materials which could be recycled after separation from each other.
• the residue of the repulped sheet material if any, is also preferably biodegradable and can be composted when disposed off in a landfill or otherwise dispose systems.
• a paper board which is coated with a water barrier coating on at least one of its uncoated surfaces having a smoothness of equal or less than 500 ml/min according to Bendtsen ISO 8791-2 or
• a paper board which is coated on at least one of its uncoated surfaces with a first surface coating based on 70 - 90 dried wt% of at least one mineral pigment and on 10 - 30 dried wt% of at least one polymeric binder, preferably with polar groups, and optionally 1 - 5 dried wt% of auxiliary agents, with the provision that all components are adding up to 100 dried wt%, and which on top of that first surface coating having a smoothness of 100ml/min or less according to Bendtsen, ISO 8791-2, is coated with a water barrier coating, wherein each of said water barrier coatings being based on at least one polymer having a melting point of at least 120 °C is applied in an amount of providing a COBB value of the water barrier coated paper board 1a), respectively 1b), of equal or less 8 g/m 2 per 600 sec and a surface energy equal or greater 38 mJ/m 2 at 20 °C (test liquid: water)
• the water barrier coating which sealable coating is based on at least one polymer, preferably with polar groups, having a melting point of at least 10 °C below the melting point of the polymer component of the water barrier coating.
• any container formed thereof according to standard paper mill processes the barrier coating of the sheet material must not interfere with these processes however must guarantee a sufficient high water and optionally grease barrier especially for any water containing foodstuff being provided in any container, especially any cup, produced from the inventive sheet material. Accordingly, none of the coatings of the paper board, respectively the containers, especially the cups produced thereof, contain or comprise any wax or wax component.
• barrier material in an amount as low as possible but sufficient high to provide the necessary water barrier expressed in a COBB value of equal or less 8 g/m 2 per 600 sec and having a surface energy equal or greater 38 mJ/m 2 at 20 °C for guaranteeing the repulpability respectively recyclability according to standard paper mill processes by allowing an easy separation between the polymer component of the water barrier coating and any fiber material of the paper board.
• this repulpability of the inventive sheet material is further improved by the fact that the necessary water barrier is already achieved with a barrier coating amounting only to 10 g/m 2 at maximum thereby preventing any fiber clouding during the repulping process. This amount decreases with increasing smoothness of the paper board surface to be coated with the water barrier coating at a given COBB value.
• a smooth surface of the paper board being coated with the water barrier coating is a requirement for achieving the necessary water barrier with such a low amount of coating.
• the inventive recyclable sheet material comprises a paper board as substrate sheet of which at least one of its uncoated surfaces has a smoothness of equal or less than 500 ml/min according to Bendtsen ISO 8791-2.
• This smoothness allows achieving the necessary water barrier expressed as a COBB value of the water barrier coated paper board of equal or less 8 g/m 2 per 600 sec, preferably 1-5 g/m 2 per 600 sec.
• the paper board 1 b)already coated on at least one of its uncoated surfaces with a first surface coating based on at least one mineral pigment and at least one polymeric binder which coated surface has a smoothness of 100ml/min or less according to Bendtsen ISO8791-2 can be coated with an even less amount of a water barrier coating, namely with an amount of as low as 3-9 g/m 2 , more preferably 4-6 g/m 2 , for achieving a COBB value of the water barrier coated paper board of equal or less 8 g/m 2 per 600 sec, preferably 1-5 g/m 2 per 600 sec.
• the inventive recyclable sheet material comprises as substrate preferably a paper board having a grammage of 170-300 g/m 2 .
• the paper board having a grammage of 170-300 g/m 2 can already have on at least one of its uncoated surfaces a first surface coating being based preferably on a dried water based dispersion consisting of at least one mineral pigment and at least one polymeric binder which polymeric binder has preferably polar groups, and optionally auxiliary agents for achieving a smoothness of 100 ml/min or less according to Bendtsen ISO 8791-2 of the coated surface.
• this first surface coating of the paper board 1 b) comprises at least one mineral pigment and at least one polymeric binder preferably with polar groups.
• the mineral pigment component is at least one mineral pigment selected from the group comprising clay, talc, calcium carbonate, titanium dioxide, kaolin or mixtures thereof, preferably clay or kaolin, most preferably clay.
• the polymeric binder is at least one polymeric binder selected from the group comprising polyacrylates, acrylate copolymers, preferably acrylate/styrene copolymers, polyvinyl acetates, ethylene/vinyl acetate copolymers, styrene
• copolymers preferably styrene/butadiene copolymers or styrene/butylacrylate copolymers, and mixtures thereof, most preferably acrylate copolymers.
• these polymers are polymers having polar groups, preferably carboxylic groups, carboxylic ester groups, carboxylic amide groups and/or OH groups.
• the first surface coating provides a surface energy equal or greater 38 mJ/ m 2 at 20°C (test liquid:water).
• the first surface coating is applied preferably as water based dispersion on at least one uncoated surface of the paper board 1 b).
• a water based dispersion used for this application may also contain the usual auxiliary agents like thickening agents, defoaming agents, dispersants, anti-block agents, anti-static agents and/or slipping agents.
• auxiliary agents like thickening agents, defoaming agents, dispersants, anti-block agents, anti-static agents and/or slipping agents.
• the amounts of all components of such first the dried surface coating are adding up to 100 dried wt%.
• the same kind of water barrier coating can be applied to at least one uncoated surface of a paper board 1a), respectively on top of the first coating of the paper board 1 b).
• Such water barrier coating is also applied preferably as a water based dispersion based on at least one polymer preferably with polar groups like carboxylic-, carboxylic ester-, carboxylic amide- and/or OH-groups and optionally usual auxiliaries.
• the polymer component of the water based dispersion is at least one polymer selected from the group comprising acrylate polymers, acrylate copolymers, methacrylate polymers, methacrylate copolymers, styrene copolymers, preferably styrene/acrylate copolymers, ethylene/vinyl acetate copolymers and mixtures thereof.
• the polymer component of the water based dispersion is at least one acrylate polymer, acrylate copolymer, methacrylate copolymer or a mixture of an acrylate polymer with a methacrylate polymer, most preferably an acrylate/styrene copolymer.
• the water barrier coating is providing a surface energy of equal or greater 38 mJ/m 2 , more preferably from 38 to 55 mJ/m 2 at 20 °C (test liquid: water).
• the water barrier coating is applied as a water based dispersion of the polymer component and optionally at least one auxiliary agent in an amount of 1-5 dried wt%.
• auxiliary agents dispersants, thickening agents, defoaming agents, cross linking agents, anti-block agents, anti-static agents and/or slipping agents can be used.
• the barrier coating is based on 95-99 dried wt% of the polymer component and 1-5 dried wt% of at least one auxiliary agent with the provision that all components are adding up to 100 dried wt%.
• the polymer component of the water barrier coating should have a melting point of at least 120 °C unless the barrier coating also serves as sealable coating. In such case, if no sealable coating 2) is present and the barrier coating also functions as sealable material, the polymer component should have a melting point of equal or less 150 °C preferably from 120 to 148 °C.
• the barrier coating does not function as a sealable material the barrier coating is covered by a sealable coating at least in designated areas.
• the heat sealable coating is applied at least partially in the areas which have to be joined for the formation of a container formed of the inventive recyclable sheet material.
• the sealable coating is based on at least one polymer, preferably with polar groups having a melting point of at least 10 °C below the melting point of the polymer component of the water barrier coating.
• the sealable coating is based on a polymer component having a melting point of 120 °C or less.
• the sealable coating is based on at least one polymer selected from the group comprising acrylate polymers, acrylate copolymers, methacrylate polymers, methacrylate copolymers, ethylene vinyl acetate copolymers, styrene copolymers, preferably styrene/acrylate copolymers and mixtures thereof, most preferable acrylate/styrene copolymers.
• the polymer used for the sealable coating has polar groups like
• carboxylic-, carboxylic ester-, carboxylic amide- and/or OH-groups providing a surface energy of equal or greater 38 mJ/m 2 , more preferably from 38 to 55 mJ/m 2 at 20 °C (test liquid: water).
• the sealable coating can optionally contain auxiliary agents like thickening agents, defoaming agents, dispersants, cross-linking agents, anti-block agents, anti-static agents and/or slipping agents in an amount of 1-5 dried wt%, more preferably the sealable coating is based on 95-99 dried wt% of the polymer component and 1- 5 dried wt% of at least one auxiliary agent, with the provision that all components are adding up to 100 dried wt%.
• auxiliary agents like thickening agents, defoaming agents, dispersants, cross-linking agents, anti-block agents, anti-static agents and/or slipping agents in an amount of 1-5 dried wt%, more preferably the sealable coating is based on 95-99 dried wt% of the polymer component and 1- 5 dried wt% of at least one auxiliary agent, with the provision that all components are adding up to 100 dried wt%.
• the sealable coating is applied on a barrier coating in an amount 12 g/m 2 at maximum, more preferably in an amount of 6-10 g/m 2 . If appropriate for the formation of a container by using the inventive recyclable sheet material this amount can be split, preferably equally between the two preferably overlapping areas that have to be combined for the formation of a container, preferably a cup.
• the polymer component of the barrier coating as well as of the sealable coating has preferably a glass transition temperature T g of 10 - 30 °C (measured according to DSC).
• the sealable coating can also be applied as a water based dispersion which is dried after the coating like the first coating of paper board 1 b), respectively each of the water barrier coatings of paper board 1 a), respectively 1 b).
• Each of the coatings namely the first surface coating, the water barrier coating and the sealable coating, can be applied according to known processes, whereby each of the coatings is dried and preferably cooled before the next coating is applied.
• the application of the coatings can be carried out continuously by using equipment already known in the art, in-line or off-line the paper board production. Off-line coating is preferred in order to have the possibility for necessary variations of the coating compositions.
• the recyclable sheet material can also be coated on both of the uncoated surfaces of the paper board with the same sequence of coatings as is applied to the first uncoated or coated surface of the paper board.
• This sequence of coatings can also be manufactured by known processes, preferably by laminating and/or coating and/or extrusion of the respective coating.
• Each coating can be applied on the paper board web, uncoated or already coated by means of blade coating, roll coating, rod coating, curtain coating or spraying.
• a further object of the present invention is a container, preferably a cup, most preferably a cup for single use, which is formed of the inventive recyclable sheet material.
• the heat sealable material of the recyclable sheet material is preferably activated by heat, preferably by hot air, and combined by pressing.
• the surface of the recyclable sheet material which is at least partially coated with the heat sealing material is preferably the inner surface of the container wall.
• the term "recyclable” means that the whole content of cellulosic material (paper board) of the inventive sheet material,
• repulpable and the contents of the non-cellulosic material like any coatings are at least repulpable according to standard paper mill processes with standard process conditions without relying on any specially configured repulping equipment.
• the amount of non-cellulosic material of the inventive sheet material, respectively of an inventive container, preferably cup, formed of the inventive sheet material is at most 15 wt% of the whole sheet material or container, preferably cup.
• the non-cellulosic material of the inventive sheet material, respectively inventive container, preferably cup, built thereof which is at least repulpable according to the before described definition is water-dispersible or water-soluble, therefore preferably it can not only be repulped but also at least partially be recycled according to the standard paper manufacturing processes or be degraded biologically according to DIN EN 13432.
• the COBB value is determined according to DIN EN 20535:1994.
• the inventive containers preferably cups, can be produced according to known manufacturing processes.
• the inventive containers are especially useful for providing hot or cold beverages, ice cream or other hot or cold liquids respectively food.
• hot or cold liquids especially aqueous liquids or ice cream, is preferred.
• inventive sheet material can also be used to produce other containers, especially for single use, than cups and optionally corresponding lids.
• These products can be trays, packages for milk and juices, plates or folded cartons for frozen foodstuff. All these kinds of containers are especially suitable for single use.

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• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Wrappers (AREA)
• Paper (AREA)
• Cartons (AREA)
• Laminated Bodies (AREA)

Priority Applications (1)

Applications Claiming Priority (3)

Publications (1)

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Family Applications (1)

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Cited By (1)

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• 2013
  • 2013-07-02 WO PCT/EP2013/001932 patent/WO2014005697A2/en active Application Filing
  • 2013-07-02 EP EP13733228.4A patent/EP2870288A2/de not_active Withdrawn
• 2014
  • 2014-12-31 US US14/588,241 patent/US20150111011A1/en not_active Abandoned

Non-Patent Citations (2)

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