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
  • 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
  • D21H17/00—Non-fibrous material added to the pulp, characterised by its constitution; Paper-impregnating material characterised by its constitution
  • D21H17/63—Inorganic compounds
  • D21H17/67—Water-insoluble compounds, e.g. fillers, pigments
• • 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
  • D21H19/32—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 obtained by reactions forming a linkage containing silicon in the main chain of the macromolecule
• • 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
  • D21H21/18—Reinforcing agents

Definitions

• the present invention relates to a paper material particularly but not exclusively suitable for use in the food industry, also in contact with food.
• the technical task of the present invention is, therefore, to provide a paper material of different grammage which obviates the drawbacks of the prior art.
• an object of the invention is to create a paper material of different grammage with intrinsic properties of extreme mechanical resistance, ability to fold without tearing, functional barrier properties to water, fats, oils and gases.
• Another object of the invention is to create a paper material of different grammage with the ability to be heat-sealable and couplable while maintaining the aforesaid properties of extreme mechanical resistance, ability to fold without tearing, functional barrier properties to water, fats, oils and gases.
• an object of the invention is to create a paper material of different grammage not only with the ability to be heat-sealable and couplable while maintaining the aforesaid properties of extreme mechanical resistance, ability to fold without tearing, functional barrier properties to water, fats, oils and gases but also with an acceptable printability.
• a paper material characterised in that it comprises a base support comprising a mixture of cellulose fibres and other natural and/or synthetic fibres, at least one polymeric substance adapted to confer to the base support mechanical resistance, water resistance and a functional barrier to water, fats, oils and gases, and an inorganic filler, said base support having a porosity comprised between 50 and 20000 sec according to the Gurley method and being coated with at least one surface coat comprising as adhesive at least one silicone from 0.1% by weight to 5% by weight of the paper material, adapted to confer to the coat functional barrier properties to water, fats, oils and gases, mechanical resistance and the ability to fold without tearing.
• said coat includes as adhesive in addition to said silicone at least one of a starch, a polyol, an acrylic polymer, a polyurethane polymer, a synthetic or natural wax.
• said fibre mixture comprises cellulose fibres, cotton fibres and synthetic fibres.
• said polymeric substance comprises one or more colophony-based and/or alkylketene-dimer-based and/or acetyl succinic-acid-based and/or epochlorohydrin-based and/or carboxymethylcellulose-based resins.
• said inorganic filler is a mineral filler comprising one or more substances selected from the group consisting of carbonates, kaolins, talc and mixtures thereof.
• the cellulose fibre content is comprised between 50% and 90% by weight.
• the present invention relates to a paper material (paper/cardboard) which, by virtue of a specially studied pulp, a specific surface treatment and a production method, has a structure with extreme mechanical resistance, with the ability to be folded without the coat tearing to ensure adequate protection from water, fats, oils and gases.
• the paper material of the invention is also printable with an acceptable printing quality and allows to obtain particular graphic effects, which are difficult to obtain with traditional treated paper materials.
• the paper material of the invention comprises a base support comprising a mixture of cellulose fibres with natural and/or synthetic fibres, at least one polymeric substance, adapted to confer to the fibre mixture mechanical resistance (dry and wet) and water resistance, and an inorganic filler, adapted to confer to the material good features of machinability and chemical stability.
• said base support has a porosity comprised between 50 and 20000 sec according to the Gurley method and is coated with at least one surface coat comprising, as an adhesive, at least one silicone from 0.1% by weight to 5% by weight of the paper material, adapted to confer to the coat functional barrier properties to water, fats, oils and gases, mechanical resistance and the ability to fold without tearing.
• the cellulose fibre content in the paper material is comprised between 50% and 90% by weight.
• the fibre mixture preferably comprises cellulose fibres, cotton fibres and synthetic fibres in a variable percentage proportion by weight: the length of the cellulose fibres is comprised between 0.2 mm and 5.0 mm; the content of the cotton fibres and the synthetic fibres in the fibre mixture is in proportions varying between 1% and 50% by weight.
• the polymeric substance included in the base support comprises one or more colophony-based and/or alkyl-ketene-dimer-based and/or acetyl succinic-acid-based and/or epochlorohydrin-based and/or carboxymethylcellulose-based resins.
• the inorganic filler is a mineral filler comprising one or more substances selected from the group consisting of carbonates, kaolins, talc and mixtures thereof.
• the formulation of the coat advantageously comprises said silicone as an adhesive and additionally at least one of a starch, a polyol, an acrylic polymer, a polyurethane polymer, a synthetic or natural wax which assist the silicone to confer to the coat functional barrier properties to water, fats, oils and gases, mechanical resistance and ability to fold without tearing.
• the grammage of the paper material according to the present invention is comprised between about 50 gr/m 2 and about 900 g/m 2 .
• the paper material is made with a substantially known paper forming technique, for example on a continuous paper manufacturing machine.
• the aqueous pulp is arranged and thereafter, water is removed from the pulp so as to form the base support of the paper material.
• the following step is the surface treatment of one or both sides of the base support with an aqueous solution comprising the silicone.
• the method can subsequently comprise, after the surface treatment of the base support with the aqueous solution, a smoothing step of the paper material which is smoothed to Bendtsen ISO 2494 smoothness values less than about 400 ml/min.
• the method advantageously comprises a step of mechanically treating the base support to obtain a porosity from 50 sec to 20000 sec according to the Gurley method.
• the method can comprise a further step of mechanical surface treatment of the paper material, in particular an embossing step.
• a paper material made in accordance with the present invention can be used in substitution of rigid plastic materials such as a support layer coupled and/or laminated to containers in the form of a bag containing liquids or gels.

Landscapes

• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Inorganic Chemistry (AREA)
• Closures For Containers (AREA)
• Wrappers (AREA)
• Paper (AREA)
• Laminated Bodies (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=80928907

Family Applications (1)

Country Status (2)

Citations (7)

• 2021
  • 2021-12-28 IT IT102021000032753A patent/IT202100032753A1/it unknown
• 2022
  • 2022-09-23 WO PCT/EP2022/076475 patent/WO2023126083A1/en unknown

Patent Citations (7)

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