TECHNOLOGY FOCUS - POLYMERS - Preparation (Claimed): The preparation of the polymer, comprises carrying out Suzuki-, Yamamoto-, Stille- or Hartwig-Buchwald polymerization. Preferred Components: The proportion of (I) and (II) in the polymer is 100 mole% or 25-75 mole%. The polymer further comprises at least one aryl structural unit of formula (-Ar9-) (III), which is different from (I) and (II). The polymer in addition to (I), (II) and optionally (III), comprises further structural units, which are different from (I), (II) and optionally (III). The crosslinkable group is terminal or cyclic alkenyl groups or terminal dienyl- or alkynyl groups, alkenyloxy-, dienyloxy- or alkynyloxy groups, acrylic acid groups, oxetane- or oxirane groups, silane groups or cyclobutane groups. The crosslinkable group comprises alkenyl groups of formula (-(CH2)s-CH=C(R11)-R12) (VIa) or (-(CH2)s-Ar10-CH=C(R11)-R12) (VIl), dienyl groups of formula (-(CH2)s-CH=CH-CH=C(R11)-R12) (VIb) or (-Ar10-(CH2)s-CH=CH-CH=C(R11)-R12) (VIm), alkynyl groups of formula (-(CH2)s-CC-R11) (VIc) or (-(CH2)s-Ar10-CC-R11) (VIn), alkenyloxy groups of formula (-(CH2)s-O-(CH2)t-CH=C(R11)-R12) (VId) or (-(CH2)s-O-(CH2)t-Ar10-CH=C(R11)-R12) (VIo), dienyloxy groups of formula (-(CH2)s-O-(CH2)t-CH=CH-CH=C(R11)-R12) (VIe) or (-AR10-(CH2)s-O-(CH2)t-CH=CH-CH=C(R11)-R12) (VIp), alkynyloxy groups of formula (-(CH2)s-O-(CH2)t-CC-R11) (VIf) or (-(CH2)s-O-(CH2)t-Ar10-CC-R11) (VIq), acrylic acid groups of formula (-(CH2)t-O-C(=O)-C(R13)=C(R11)-R12) (VIg), (-(CH2)t-C(=O)-C(R13)=C(R11)-R12) (VIh), (-Ar10-(CH2)t-O-C(=O)-C(R13)=C(R11)-R12) (VIr), (-Ar10-(CH2)t-C(=O)-C(R13)=C(R11)-R12) (VIs), oxetane groups of formula (VIi), (VIj), (VIt) or (VIu), oxirane groups of formula (VIk) or (VIv), ethane-1,2-diyl or ethane-1,2-diyl groups of formula (-CH2-CH2-Ar10) (Viw). The proportion of (I) in the polymer is 1-99 mole% based on 100 mole% of all copolymerized monomers, which are present in the polymer as structural units. The proportion of (II) in the polymer is 1-99 mole% based on 100 mole% of all copolymerized monomers, which are present in the polymer as structural units. The proportion of (I) and/or (II) exhibiting the crosslinkable group, in the polymer, is 0.1-50 mole% based on 100 mole% of all copolymerized monomers, which are present in the polymer as structural units.Ar9 = mono- or polycyclic and (hetero)aromatic ring (optionally substituted by at least one group R);R11-R13 = H or 1-6C alkyl;Ar10 = Ar9;s = 0-8; andt = 1-8. Preferred Definitions:    Ar1, Ar6, Ar7 = substituted phenyl moieties of formula (IVa), substituted biphenyl moieties of formula (IVb), substituted terphenyl moieties of formula (IVc) or (IVd), substituted triphenylbenzene moieties of formula (IVe), substituted naphthalenyl moieties of formula (IVf), substituted phenanthrenyl moieties of formula (IVg), substituted heterocyclyl moieties of formula (IVh) (IVj), (IVk) or (IVl) or substituted 9,9'-spirobi(fluorenyl) moieties of formula (IVi);    X = C(R)2, Si(R)2, NR, O or S;    m = 0-2;    n = 0-3;    o = 0-4;    p = 0-5;    Ar2, Ar3, Ar5, Ar7-Ar9 = 23 aryl moieties e.g. substituted benzene-diyl moieties of formula (IVa), substituted biphenyl-diyl moieties of formula (Vb), substituted terphenyl-diyl moieties of formula (Vc) or (Vd), substituted naphthalen-diyl moieties of formula (Ve) or (Vf), substituted phenanthren-diyl moieties of formula (Vg), (Vh) or (Vi), substituted binaphthalenyl-diyl moieties of formula (Vj), substituted heterocyclyl moieties of formula (Vk) and substituted phenyl moieties of formula (Vl);    Ar4 = (IVa)-(IVl) or 23 aryl moieties e.g. (IVa)-(Vl);    X1 = C(R)2, Si(R)2, O or S;    Y1 = 1-20C alkyl, 2-20C alkenyl or 2-20C alkynyl (in all groups at least one non-adjacent CH2 group, CH group and C are optionally replaced by Si(R1)2, C=O, C=S, C=NR1, P(=O)(R1), SO, SO2, NR1, O, S or CONR1), (hetero)aromatic ring with 5-60 aromatic ring atoms, (hetero)aryloxy with 5-60 aromatic ring atoms, (hetero)aralkyl with 5-60 aromatic ring atoms, diarylamino with 10-40 aromatic ring atoms, diheteroarylamino with 10-40 aromatic ring atoms or aryl-heteroaryl-amino with 10-40 aromatic ring atoms (all optionally substituted by at least one group R1), C(R)2, Si(R)2, O or S;    k = 0 or 1; and    q = 0-6.    EXAMPLE - 10% 4-(Bis-(4-(4,4,5,5-tetramethyl-(1,3,2)dioxaborolan-2-yl)-phenyl)-amino)-benzaldehyde, 40% (4-tert-butyl-phenyl)-bis-(4-(4,4,5,5-tetramethyl-(1,3,2)dioxaborolan-2-yl)-phenyl)-amine and 50% N2,N7-bis(4-bromophenyl)-2',7'-di-tert-butyl-N2,N7-bis(4-tert-butylphenyl)-9,9'-spirobi(fluorene)-2,7-diamine were subjected to Suzuki coupling to obtain the crosslinkable polymer (having a weight average molecular weight of 240000 g/mole, and a polydispersity of 3.3.