A hydrolytic sheet is obtained by impregnating a base paper sheet with an aqueous agent. The base paper sheet has a weight per unit area of 30 to 150 gsm and includes a water-soluble binder. The aqueous agent includes a cross-linking agent which cross-links with the water-soluble binder and cellulose nanofiber.

The present invention relates to a barrier film for a paper or paperboard-based packaging material, said barrier film comprising: a substrate; a vacuum coating layer having a thickness in the range of 1-500 nm disposed on the substrate; and a protective coating layer comprising a crosslinked water-soluble polymer disposed on the vacuum coating layer. The present invention further relates to a paper or paperboard based packaging material and containers comprising the barrier film, and to a method for manufacturing the barrier film.

The present invention relates to a barrier film for a paper or paperboard-based packaging material, said barrier film comprising: a substrate; a vacuum coating layer having a thickness in the range of 1-500 nm disposed on the substrate; and a protective coating layer comprising a crosslinked water-soluble polymer disposed on the vacuum coating layer. The present invention further relates to a paper or paperboard based packaging material and containers comprising the barrier film, and to a method for manufacturing the barrier film.

A method for manufacturing a multi-layered paperboard is disclosed, which includes at least two fibrous layers, in which method at least one layer of the multi-layered paperboard is treated by applying an aqueous solution of a first strength component in dissolved form including anionic strength polymer and/or amphoteric strength polymer composition on a surface of layer, and an aqueous solution of a cationic second strength component in dissolved form is added to a fibre stock from which at least one of the fibrous layers joined together is formed.

A method for manufacturing a multi-layered paperboard is disclosed, which includes at least two fibrous layers, in which method at least one layer of the multi-layered paperboard is treated by applying an aqueous solution of a first strength component in dissolved form including anionic strength polymer and/or amphoteric strength polymer composition on a surface of layer, and an aqueous solution of a cationic second strength component in dissolved form is added to a fibre stock from which at least one of the fibrous layers joined together is formed.

A fiber body forming method includes a step of preparing a web which contains fibers and which has a bulk density of 0.09 g/cm.sup.3 or more; and a step of applying a liquid containing a binder which binds the fibers together to the web.

A fiber body forming method includes a step of preparing a web which contains fibers and which has a bulk density of 0.09 g/cm.sup.3 or more; and a step of applying a liquid containing a binder which binds the fibers together to the web.

A coated paperboard comprising a paperboard substrate having a first side and a second side and a coating in contact with the first side of the paperboard substrate, the coating including binder and pigment, the coating containing substantially no fluorochemical or wax, wherein the coated paperboard has a 3M kit test value of at least 3, and wherein the coated paperboard is repulpable.

A coated paperboard comprising a paperboard substrate having a first side and a second side and a coating in contact with the first side of the paperboard substrate, the coating including binder and pigment, the coating containing substantially no fluorochemical or wax, wherein the coated paperboard has a 3M kit test value of at least 3, and wherein the coated paperboard is repulpable.

There is provided: a method for controlling corrosion-resistant paper with easy decomposability, whereby the paper has corrosion resistance against decomposition due to microorganisms in soil when raising seedlings, the paper retains satisfactory strength during agricultural planting, and desired decomposability is given to the paper after planting or after harvest of crops; and a method for producing corrosion-resistant paper with controlled decomposability. The controlling method is subjected to corrosion-resistant paper containing paper with cellulose fibers and a carboxylic acid crosslinking agent at least partially bonded to each other, the controlling method including a step for treating the corrosion-resistant paper with alkali; and the producing method comprises a step for applying a processing solution containing a carboxylic acid crosslinking agent to paper containing cellulose fibers, a step for subjecting the paper to a heating treatment, and a step for treating the paper undergone the heating treatment with an alkali.