Patent ID: 6858703

Claim:
A composition comprising an inert diluent, optionally substantially electrorephotographically inert, and at least one polymeric material, optionally in a substantially pure form, wherein the polymeric material comprises at least one repeat unit, the or each (if more than one) repeat unit consisting substantially of a moiety of Formula 1: in which: Y 1 represents, independently if in different repeat units, N, P, S, As and/or Se; Ar 1 and Ar 2 which may be the same or different, represent, independently if in different repeat units, a multivalent aromatic group optionally substituted by at least one optionally substituted C 1-40 carbyl-derived groups and/or at least one other optional substituent, and Ar 3 represents, independently if in different repeat units, a mono or multivalent aromatic group optionally substituted by at least one; optionally substituted C 1-40 carbyl-derived group and/or at least one other optional subsequent; except when Y 1 is divalent S or divalent Se, Ar 3 and the arrow therefrom are not present; the arrow from Ar 3 indicates, in the case where Ar 3 is monovalent, a bond to a terminal group inert to coupling in the polymerisation to form said polymeric material, or, in the case where Ar 3 is multivalent, a bond to another said repeat unit; where at least one terminal group is attached in the polymer to the Ar 1 , Ar 2 and optionally Ar 3 groups located at the end of the polymer chains, so as to cap the polymer chains and prevent further polymer growth, and at least one terminal group is derived from at least one end capping reagent used in the polymerisation to form said polymeric material to control the molecular weight thereof.