The process according to claim 10, wherein said binder comprises a copolymer comprising from 70 to 30 weight % of monomer residues of Formula I wherein n is 0, and one of R1 and R2 is a hydrogen atom and the other is a methyl radical and from 30 to 70 weight % of monomer residues of Formula I wherein n is 0, and both R1 and R2 are hydrogen atoms.