▎ 摘　　要

NOVELTY - Method for preparation of aqueous composition of reduced graphene oxide, involves (a) providing an aqueous dispersion comprising graphene oxide, where the graphene oxide comprises monolayer flakes of graphene oxide and multilayer graphene oxide platelets, having up to 20, such as 2-10, stacked monolayer flakes of graphene oxide, (b) providing an aqueous dispersion of nanocellulose compound, (c) providing an aqueous solution of a reducing agent, (d) uniformly mixing the aqueous dispersions from step (a) and (b), (e) adding the aqueous solution of the reducing agent to mixture obtained from step (d), and (f) allowing the reducing agent to reduce the graphene oxide in mixed aqueous composition to form aqueous gas-barrier coating composition comprising well dispersed and reduced graphene oxide. USE - The method is used for preparing aqueous composition of reduced graphene oxide used for producing gas-barrier coated material, which is used as oxygen barrier material in laminated packaging material for liquid food products and packaging container (all claimed), preferably liquid carton packaging containers for liquid carton food packaging, and used as gas barrier coating composition from graphene oxide in aqueous dispersion. The aqueous composition is applied to substrate material web in form of ink and/or dispersion coating. ADVANTAGE - The method applies reduced graphene-oxide based materials into laminated packaging materials at reasonable cost, satisfies the future requirements regarding recyclability and sustainable material sourcing and manufacturing, provides improved method for manufacturing substrate materials coated with barrier coating from reduced graphene-oxide, laminates such barrier-coated substrate materials to packaging materials, provides simplified method for manufacturing barrier coated substrate with reduced graphene oxide, provides excellent barrier properties, such as recyclability and capability to fulfill the requirements regarding future sustainable liquid carton laminated packaging materials, manufactures non-foil laminated packaging materials for oxygen-sensitive, liquid, semi-solid or wet food products, which do not contain aluminum foil but nevertheless have excellent gas barrier properties suitable for long-term, aseptic packaging at reasonable cost, adopts cost-efficient aluminum foil barrier materials, non-foil, paper or paperboard-based and laminated packaging material, and provides cost-efficient non-foil, paper or paperboard-based, mechanically robust and heat-sealable packaging laminate with excellent gas barrier properties, which maintains long-term storage of liquid foods with nutritional quality under ambient conditions. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for the following: (1) a method for producing a gas-barrier coated material by coating a substrate material with a layer of reduced graphene oxide, involving (i) providing a substrate material, (ii) providing the aqueous gas-barrier coating composition comprising above-mentioned reduced graphene oxide, (iii) coating the aqueous gas-barrier coating composition of reduced graphene oxide to a surface of the substrate material, (iv) drying the wet coated substrate material obtained from step (iii), by forced evaporation, to obtain a dry layer of layered reduced graphene oxide particles or flakes on surface of substrate material to form gas-barrier coated material; (2) a gas-barrier coated substrate material prepared by above-mentioned method; and (3) a laminated packaging material comprising gas-barrier coated substrate material, and further comprising a first outermost protective material layer and a second innermost liquid tight, and heat sealable material layer.