Processes for production of azo macroinitiators for the synthesis of block copolymers and of aqueous block copolymer dispersions and emulsions and the use thereof

A composition comprising a block-copolymer neutralized with an acid and dissolved, dispersed or emulsified in water,

• said block-copolymer having an amine number between 5 and 200 mg KOH before neutralization and having been prepared by reaction of at least one radically polymerizable monomer having amino groups with an azo-macro-initiator in water,
• said azo-macro-initiator having a number average molecular weight between 1500 and 60000 and having been prepared by reaction of at least one prepolymer having isocyanate-reactive end groups, said pre-polymer being selected from the group consisting of polyurethanes, polyacrylates, polymethacrylates, polyesters, polybutadienes, aminopropyldimethylpolysiloxanes, polydimethylsiloxanecarbinols, polyethers, polyepoxides, polylactones, polycarbonates and polyamides, with an azodiisocyanate prepared by reaction of a diisocyanate and a thermally decomposable azo-initiator containing at least 2 hydroxy groups.