Phosphoric acid esters and their use as dispersing agent

摘要

Phosphate esters of amphiphilic block copolymers consisting of poly(alkyl)styrene or polystyrene oxide segments and polyalkylene oxide segments. Phosphate esters of formula (I) are new: R = (IIa) or (IIb); x = 1 or 2; n = 2-18; m, o = 2-100; k = 2-4; R = H or alkyl (optionally substituted with other functional groups); R' = alkyl, alkaryl, alkenyl or sulfopropyl. Independent claims are also included for: (a) the production of (I) by (A) reacting an omega -hydroxy-functional oligo- or poly-(alkyl)styrene with an alkylene oxide to give a poly(alkyl)styrene-polyalkylene oxide block copolymer and then esterifying this by reaction with a phosphate ester-forming compound so that up to 100% of the terminal OH groups undergo reaction and the phosphorus atoms are mono- and/or di-esterified; or (B) reacting a phosphate ester-forming compound as above with a polystyrene oxide-polyalkylene oxide block copolymer obtained from a monofunctional starting alcohol by addition of styrene oxide and alkylene oxide to give segments of the required chain length in the required sequence; and (b) pigment preparations and aqueous pastes based on inorganic or organic pigments or dyes, containing 1-100 wt% ester (I) as dispersant (based on pigment or dye), especially aqueous carbon black paste containing 10-100 wt% (I).