METHOD TO MAKE PAPER RESISTANT TO CONTAMINATION AND CONTAMINATION-RESISTANT PAPER Russian patent published in 2011 - IPC D21H19/24 B42D15/00 

FIELD: textile, paper.

SUBSTANCE: method to make paper consists in making a paper web and application of a coating on it, which contains non-pigmented dispersion of aliphatic polyurethane. Then a coating with applied at least in one layer with solid residue of less than 3.5 g/m² onto one or two sides of the paper web, which has been previously treated in a gluing press or an impregnation bath with a solution of polyvinyl alcohol. At the same time dispersion has dynamic viscosity of more than 10 mPa·s with temperature of 25°C and particle size determined by light scattering method of less than 0.1 micron. The film made of this dispersion and hardened at the temperature of 21°C for 5 days has an index of gel-fraction in acetone of more than 30%.

EFFECT: production of paper with high-quality coating and high printing properties, increased resistance of paper to contamination.

2 cl, 4 dwg, 5 tbl