Compounds with carbodiimide units and carboxyl or carboxylate groups (compounds V), derived from

a) aliphatic or araliphatic C₄ to C₂₀ polyisocyanates (component a)

b) hydroxy carboxylic acids or hydroxy carboxylic salts (component b) and

c) if desired, further compounds, carrying groups able to react with isocyanate groups in an addition reaction (component c)

d) if desired, other isocyanates (component d),

the carbodiimide units being derived essentially exclusively from the isocyanate groups of component a).