FIELD: chemistry.
SUBSTANCE: invention relates to wax dispersions in form of nanoparticles, used for hydrophobisation of lignocellulose- and/or cellulose-based materials. The wax dispersion contains water as a continuous phase, an emulsifying agent and wax which forms the dispersed phase. More than 85 wt % of the wax is made up of one or more long-chain hydrocarbons containing more than 20 carbon atoms on average, and the wax has hardening temperature ranging from higher than 40 to 150°C. The dispersed wax in form of solid particles has mean particle diameter from 10 to less than 500 nm. The wax dispersion is obtained by heating a mixture containing water, an emulsifying agent and wax to temperature higher than the melting point of the wax, and the molten wax is emulsified using a dispersant and then cooling to temperature lower than the hardening temperature of the dispersed wax phase. Hydrophobisation of materials is carried out by bringing said materials into contact with said wax dispersion and then pressing the material.
EFFECT: obtained wax dispersions contain a large weight ratio of a dispersed wax phase, are stable during storage and are resistant to shearing stress, provide a high hydrophobic effect compared to standard wax dispersions with the same content of wax.
23 cl, 3 tbl, 6 ex
Authors
Dates
2012-05-10—Published
2007-03-28—Filed