COMPOSITIONS OF POLYOLEFIN DISPERSIONS TO PROVIDE HIGH RATE OF PASSAGE OF VAPOURS THROUGH HYDROPHOBIC COATINGS

摘要

FIELD: chemistry.;SUBSTANCE: invention relates to mixtures of aqueous polyolefin dispersions. Described is a composition for producing a water vapour-permeable hydrophobic coating. Composition comprises a mixture of (i) primary polyolefin dispersion of one or more polyolefin-containing particles with average particle size of 1–5 mcm and melting point not lower than 95 °C, volatile base and dispersant - linear carboxylic acid containing 14–40 carbon atoms, and (ii) a film-forming second dispersion of one or more polymers with average particle size of 0.1–1.0 mcm selected from among one or more polyolefins having a melting point of 50–90 °C, additionally containing at least partially neutralized olefin-containing dispersant. Ratio of particle size of primary dispersion of polyolefin to size of particles of second dispersion is in range from 3:1 to 29:1.;EFFECT: coatings made from the disclosed composition provide high rate of water vapour passage to form a hydrophobic surface which prevents penetration of liquid water into the coating or through it.;10 cl, 4 tbl, 48 ex