COATING COMPOSITIONS FOR BUILDING MATERIALS AND SUBSTRATES OF BUILDING MATERIALS WITH COATING Russian patent published in 2018 - IPC C09D109/08 C09D5/02 D06N3/10 D21H19/40 D21H19/56 D21H19/58 D21H19/60 

FIELD: chemistry.

SUBSTANCE: coating composition adapted to selectively retain water vapour as a function of humidity when cured to form a barrier layer, comprises a hydrophobic component comprising a styrene-butadiene latex having a carboxylation of 0 to 20%; a hydrophilic component comprising a polymer selected from polyvinyl alcohol and sodium polyacrylate and a hydrophilic filler selected from kaolin clay; the coating composition after curing is effective to provide variable water vapour permeability of 1 perm or less at an average relative humidity of RH of 25% and about 15 Perm or more at an average relative humidity of 95% as measured by ASTM E96 at 21°C, and tested by applying and curing the composition on craft paper. The invention also relates to an article capable of selectively retaining water vapour, depending on humidity, comprising a substrate of a building material and a barrier layer applied to a substrate of a building material obtained by curing the above coating composition. The coated article is designed in such a way that it can exhibit a certain permeability profile such as, for example, a variable value of water vapour permeability of about 1 Perm or less at an average relative humidity of RH of 25% and about 15 Perm or more at an average relative humidity of 95 %, measured according to ASTM E96 at 21°C.

EFFECT: improvement of characteristics.

13 cl, 3 dwg, 2 tbl