Poly-electrolyte polymer composition and its use

A method of applying a poly-electrolyte composition to a carrier, which method comprising the steps of:

• providing the carrier with an aqueous reaction mixture comprising at least a first hydrophilic monomer and a second hydrophilic monomer, and
• causing the monomers to polymerize on the carrier under the influence of an energy source wherein radical formation occurs and the polymerization is started and wherein crosslinking between individual polymer chains occurs, so as to form a water insoluble, crosslinked polyelectrolyte copolymer,
• wherein the first monomer is selected from the group consisting of vinylic sulphonic acids, vinyl phosphonic acids or a water soluble salt thereof as shown in the formula I-IV,
• wherein R1, R2, R3 represent hydrogen, optionally substituted alkyl or aryl group, Q represents an alkylene group and M represents hydrogen or cation, and
• the second monomer is a vinylic monomer with a double bond, which monomer comprises at least one acid group and a spacer group arranged between the double bond and the acid group, and the second monomer is different from the first monomer and at least one compound selected from the group consisting of monomers comprising an acid group being either in a free acid form or in a form of a water soluble salt, and of which the logarithm of the acid dissociation constant (pKa) in the free acid form has a value smaller than 3.5.