Liquid crystal poly:di:methyl:siloxane copolymer - with high di:methyl-siloxane fraction, for liquid crystal compsn., esp. for electro-optical device

摘要

Liquid crystal polydimethylsiloxane copolymers of the formula X1-SiMe2-((O-SiMe2)l (O-SiMeY1)m (O-SiMeY2)p(O-SiMeY3)q (O-SiMeY4)r )nO-SiMe2X2 (I) and the corresp. cyclic copolymers of formula (II), with a dimethylsiloxane (DMS) fraction of at least 0.75 in the main chain, are new: l, m, p, q, r and s are 0-100 such that l+m+p+q+r+s is over 2 and at least 2 of m, p, q, r and s are over 0; n is 1-500; X1-2 is (CH2)t-CH3, (CH2)t-COCH, (CH2)t-Cl, (CH2)t-MNH2, (CH2)t-OH, (CH2)t-O-CO-OH, or (O-CH2-CH2)t-OH; t is 0-20; Y1-5 are -CH2CH2(CH2)a(-B)b-M1(A1)c (-M2)d(-A2)e(-M3)f(-A3)g-R1 (III); -(CH2)a-CH2(CH2-CH2-O)a -(B)b- M1(-A1)c(-M2)d(-A2)e (-M3)f(-A3)g-R1 (IV) or -(CH2)a'-CH2-CH2-CH((CH2)a'')- COO-(B)b-M1(-A1)c (-M2)d(-A2)e (-M3)f(-A3)g-R1)2 (V); B is CHR6-CXR7-CXR8, CHR6-O-CHR7-CXR8, CXR6-CXR7-O-CHR8 or (i); R6-R8 are H, Me, OMe, F, Cl or Br, at least one of R6-R8 being H; X is H, F, Cl or Br; R9 is H or 1-10C alkyl; R1 is 1-16C alkyl (with(out) asymmetrical C atom) or 2-16C alkenyl, in which 1 or 2 non-adjacent -CH2- gps. may be replaced by -O-, -S-, -CO-, -CO-O-, -O-CO- or -O-CO-O- and H may be replaced by F, or a chiral epoxy or ether-contg. gp.; R2-R5 are 1-16C alkyl or 2-16C alkenyl, in which -CH2- gp. may be replaced by -O-, -CO-O- or -O-CO-, or R2R3 and/or R4R5 are 3-8C cycloalkyl; G is 1-16C alkylene or 2-16C alkenylene, in which 1 or 2 non-adjacent -CH2- gps. may be replaced by -O-, -S-, -O-CO-, -CO-O-, -S-CO- or -CO-S-; a, a' and a'' are 1-20, pref. 1-12; b, c, d, e, f and g are 0 or 1 such that e+f+g are 2 or 3; A1-A3 are 1,4-phenylene (Phe), in which 1 or 2 H may be replaced by F, Cl and/or CN, trans-1,4-cyclohexylene (Cyc), in which 1 or 2 H may be replaced by F, Cl, CN and/or Me, pyrazin-2,5-diyl (Pyz), pyridazin-3,6-diyl, pyridin-2,5-diyl (Pyr), pyrimidin-2,5-diyl (Pym, (1,3,4)-thiadiazol-2,5-diyl (Thiz), 1,3-dioxan-2,5-diyl or 1,3-dithian-2,5-diyl; M2M3 are CO-O, O-CO, CO-S, S-CO, CH2-O or O-CH2; M1 is O, O-CO, CO-O or CH2-CH2. USE/ADVANTAGE - (I) and/or (II) are used in LC mixts., pref. with S(asterisk)c phase at least in the 10-50 deg.C range, which are used in electro-optical devices (claimed). They give esp. short switching times in LCD's.