Water-based barrier coatings

A method for barrier coating a subject, comprising:

• providing a water-based barrier coating composition containing:
• (A):
• (i) 40 to 95% by weight of a total weight of (A), an aqueous polymer composition obtainable by free radical (co)polymerizing an ethylenically unsaturated monomer blend containing:
• (a) 0 to 70% by weight of at least one optionally substituted styrene,
• (b) up to 100% by weight of at least one C1-C4-alkyl (meth)acrylate,
• (c) 0 to 10% by weight of other ethylenically unsaturated copolymerizable monomers, in a presence of,
• (d) 0 to 40% % by weight of degraded starch having a molecular weight Mn of 500 to 10,000, wherein a sum (a)+(b)+(c)+(d) is 100%;
• (ii) 2 to 55% by weight of the total weight of (A) of polyvinyl alcohol (PVA), optionally polymerized together with components of (i);
• (iii) 2 to 30% by weight of the total weight of (A) of a plasticizer;
• (iv) 5 to 30% by weight of the total weight of (A) a composition containing C16-C18 alkenyl ketene dimer, optionally as a mixture with rosin, whereby a ratio of the C16-C18 alkenyl ketene dimer:rosin is from 100:0 to 25:75;
• (v) 5 to 20% by weight of the total weight of (A) of a gelling agent;
• and
• (B):
• a filler, wherein a ratio of (A):(B) is from 2:5 to 1:1;
• and
• applying the water-based barrier coating composition to at least part of a surface of a subject by
• applying the water-based barrier coating composition as a first water-based coating composition, wherein said first water-based coating composition contains (A) and (B), to at least part of a surface of a subject to obtain a precoated subject;
• and
• then applying the second water-based barrier coating composition as a second water-based composition, wherein said second water-based coating composition comprises (A) but does not contain (B), to at least a precoated surface of the subject to obtain a top coated subject.