Patent ID: 7723425

Claim:
A composition comprising a) 0.1-99.9% by weight dispersible inorganic or organic pigment particles; and b) 0.1-99.9% by weight dispersing agents that essentially consist of a combination of (i) polymer of the formula {X-[(A x -B y )} p —Y] q (I), wherein X represents the fragment of a polymerisation initiator capable of initiating polymerisation of ethylenically unsaturated monomers by atom transfer radical polymerisation (ATRP) in the presence of a catalyst capable of activating controlled radical polymerisation by ATRP; Y represents a polymer chain terminal group, a polymerisable chain terminal group or a saturated polymer chain terminal group; A and B are represent polymer blocks composed of repeating units of ethylenically unsaturated monomers selected from the group consisting of styrenes, acrylic and methacrylic acid-C 1 -C 24 alkyl esters, acrylic and methacrylic acid-hydroxy-C 2 -C 6 alkyl esters, acrylic and methacrylic acid-dihydroxy-C 3 -C 4 alkyl esters and acrylic and methacrylic acid esters having poly-C 2 -C 4 alkyleneglycol ester groups, wherein the ester groups may be substituted with C 1 -C 24 alkoxy groups; and wherein at least one of the polymer blocks A or B or the chain terminal group Y additional contains repeating units of ethylenically unsaturated monomers substituted with basic residues which are representing by a compound of the formula CH 2 ═C(—R 1 )—C(═O)—R 2 (III), wherein R 1 represents hydrogen or methyl; and R 2 represents a basic residue selected from the group consisting of amino-C 2 -C 4 alkoxy, C 1 -C 4 alkylamino-C 2 -C 4 alkoxy, di-C 1 -C 4 alkylamino-C 2 -C 4 alkoxy, hydroxyl-C 2 -C 4 alkylamino-C 2 -C 18 alkoxy and C 1 -C 4 alkyl-(hydroxyl-C 2 -C 4 alkyl)amino-C 2 -C 4 alkoxy; one of x and y represents zero, one or a numeral greater that one and the other one represents a numeral greater than one; p and q are 1; and (ii) a salt forming compound selected from the group consisting of monocyclic or polycyclic sulphonic, mono- or polycyclic carboxylic or phosphonic acids, aliphatic sulphonic, carboxylic or phosphonic acids substituted with mono- or polycyclic groups, C 1 -C 8 alkyl halides substituted with polycyclic groups, 2-chlorobenzylchloride, 4-chlorobenzylchloride, 2,4-dichlorobenzylchloride and C 1 -C 4 alkyl esters of mono- or polycyclic sulphonic acids; with the proviso that p-toluenesulphonic acid is excluded as salt-forming component (ii).