Industrial deinking of ink compositions

The ink composition comprises pigment particles and a stimulus responsive dispersing agent for dispersing said pigment particles in a protic polar solvent， for instance for inkjet printing， which stimulus responsive dispersing agent comprises an anchoring part for anchoring to said pigment particles， a stimulus responsive part as shown in formula (XXa) or (XXb) and a hydrophilic part for solvent stabilization of the pigment， wherein the stimulus responsive part upon exposure to a stimulus initiates decomposition of the stimulus responsive dispersing agent. The paper with the printed ink can be deinked in an industrial deinking process.