U.S. patent application number 14/273770 was filed with the patent office on 2014-08-28 for liquid-crystal display.
This patent application is currently assigned to MERCK PATENT GMBH. The applicant listed for this patent is Merck Patent GmbH. Invention is credited to Eun Young KIM, Eun-Kyu LEE, Seung-Eun LEE, Dong-Mee SONG.
Application Number | 20140240653 14/273770 |
Document ID | / |
Family ID | 41417953 |
Filed Date | 2014-08-28 |
United States Patent
Application |
20140240653 |
Kind Code |
A1 |
LEE; Seung-Eun ; et
al. |
August 28, 2014 |
LIQUID-CRYSTAL DISPLAY
Abstract
The present invention relates to the use of LC (liquid-crystal)
compounds and LC media comprising them in LC displays of the PS
(polymer stabilised) or PSA (polymer sustained alignment) type.
Inventors: |
LEE; Seung-Eun; (Seoul,
KR) ; KIM; Eun Young; (Gunpo, KR) ; SONG;
Dong-Mee; (Hwasung, KR) ; LEE; Eun-Kyu;
(Daejeon, KR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Merck Patent GmbH |
Darmstadt |
|
DE |
|
|
Assignee: |
MERCK PATENT GMBH
Darmstadt
DE
|
Family ID: |
41417953 |
Appl. No.: |
14/273770 |
Filed: |
May 9, 2014 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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13394453 |
Mar 6, 2012 |
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PCT/EP2010/004962 |
Aug 13, 2010 |
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14273770 |
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Current U.S.
Class: |
349/183 ;
252/299.63; 252/299.66; 29/825 |
Current CPC
Class: |
C09K 19/3003 20130101;
C09K 19/44 20130101; C09K 19/12 20130101; C09K 2019/548 20130101;
C09K 2019/123 20130101; C09K 2019/0448 20130101; C09K 2019/301
20130101; C09K 2019/3009 20130101; Y10T 29/49117 20150115; C09K
2019/124 20130101; C09K 19/542 20130101; C09K 2019/3016 20130101;
C09K 2019/3015 20130101; G02F 1/1334 20130101; C09K 2019/3004
20130101 |
Class at
Publication: |
349/183 ;
252/299.66; 252/299.63; 29/825 |
International
Class: |
C09K 19/54 20060101
C09K019/54; G02F 1/1334 20060101 G02F001/1334; C09K 19/30 20060101
C09K019/30 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 8, 2009 |
EP |
09011466.1 |
Claims
1-15. (canceled)
16. A PS or PSA display, which PSA display is a PSA-VA, PS-IPS or
PS-FFS display, comprising an liquid crystalline mixture, which has
a negative dielectric anisotropy, and one or more polymerizable
compounds or reactive mesogens, or a polymer obtained by
polymerizing one or more polymerizable compounds or reactive
mesogens, wherein the liquid crystalline mixture comprises one or
more compounds of formula I ##STR00213## in which ##STR00214##
denote independently of each other ##STR00215## R.sup.1 denotes
alkyl or alkenyl having 1 to 12 C atoms, in which optionally one or
two non-adjacent CH.sub.2 groups are replaced by --O--,
--CH.dbd.CH--, --CO--, --OCO-- or --COO-- in such a way that O
atoms are not linked directly to one another, R.sup.0 has one of
the meanings given for R.sup.1 or denotes X.sup.0, X.sup.0 is F,
Cl, halogenated alkyl or alkoxy having 1 to 6 C atoms, or
halogenated alkenyl or alkenyloxy having 2 to 6 C atoms, L.sup.1
and L.sup.2 each, independently of one another, denote F, Cl,
OCF.sub.3, CF.sub.3, CH.sub.3, CH.sub.2F, CHF.sub.2, and p denotes
0, and wherein one or more compounds of formula I contain one or
more rings ##STR00216## and/or two or more rings ##STR00217##
17. A PS or PSA display according to claim 16, wherein a compound
of formula I is of one of the following formulae: ##STR00218##
wherein alkyl denotes a straight-chain alkyl radical with 1 to 6 C
atoms, (O) denotes an O atom or a single bond, and Q denotes F or
OCF.sub.3.
18. A PS or PSA display according to claim 16, wherein the LC
mixture additionally comprises one or more compounds of the
following formulae: ##STR00219## wherein a denotes 1 or 2, b
denotes 0 or 1, ##STR00220## denotes ##STR00221## R.sup.1 and
R.sup.2 each, independently of one another, denote alkyl or alkenyl
having 1 to 12 C atoms, in which one or two non-adjacent CH.sub.2
groups are optionally replaced by --O--, --CH.dbd.CH--, --CO--,
--OCO-- or --COO-- in such a way that O atoms are not linked
directly to one another, Z.sup.x and Z.sup.y each, independently of
one another, denote --CH.sub.2CH.sub.2--, --CH.dbd.CH--,
--CF.sub.2O--, --OCF.sub.2--, --CH.sub.2O--, --OCH.sub.2--,
--CO--O--, --O--CO--, --C.sub.2F.sub.4--, --CF.dbd.CF--,
--CH.dbd.CH--CH.sub.2O--, or a single bond, and L.sup.1-4 each,
independently of one another, denote F, Cl, OCF.sub.3, CF.sub.3,
CH.sub.3, CH.sub.2F, or CHF.sub.2.
19. A PS or PSA display according to claim 18, wherein the LC
mixture comprises one or more compounds of formulae CY, and/or PY,
which contain an alkenyl group.
20. A PS or PSA display according to claim 18, wherein in formula
CY and PY, Z.sup.x and Z.sup.y denote a single bond.
21. A PS or PSA display according to claim 18, wherein in formula
CY and PY, L.sup.1-4 denote F or Cl.
22. A PS or PSA display according to claim 16, wherein the LC
mixture additionally comprises one or more compounds of the
following formulae: ##STR00222## in which ##STR00223## denotes
##STR00224## denotes ##STR00225## denotes ##STR00226## R.sup.3 and
R.sup.4 each, independently of one another, denote alkyl having 1
to 12 C atoms, in which one or two non-adjacent CH.sub.2 groups are
optionally replaced by --O--, --CH.dbd.CH--, --CO--, --OCO-- or
--COO-- in such a way that O atoms are not linked directly to one
another, Z.sup.y denotes --CH.sub.2CH.sub.2--, --CH.dbd.CH--,
--CF.sub.2O--, --OCF.sub.2--, --CH.sub.2O--, --OCH.sub.2--,
--COO--, --OCO--, --C.sub.2F.sub.4--, --CF.dbd.CF--,
--CH.dbd.CHCH.sub.2O-- or a single bond, R.sup.5 and R.sup.6 each,
independently of one another, denote alkyl or alkenyl having 1 to
12 C atoms, in which optionally one or two non-adjacent CH.sub.2
groups are replaced by --O--, --CH.dbd.CH--, --CO--, --OCO-- or
--COO-- in such a way that O atoms are not linked directly to one
another, and e denotes 1 or 2.
23. A PS or PSA display according to claim 22, wherein the LC
mixture comprises one or more compounds of formulae ZK and/or DK,
which contain an alkenyl group.
24. A PS or PSA display according to claim 22, wherein in formula
DK, Z.sup.y denotes a single bond.
25. A PS or PSA display according to claim 22, wherein the LC
mixture contains one or more compounds of formula ZK3 ##STR00227##
in which alkyl denotes a straight-chain alkyl radical having 1-6 C
atoms, and alkenyl denotes a straight-chain alkenyl radical having
2-6 C atoms.
26. A PS or PSA display according to claim 16, wherein the one or
more polymerizable compounds or reactive mesogens are of formula I*
or II* R.sup.a--B.sup.1--(Z.sup.1--B.sup.2).sub.m1--R.sup.b I*
(R*--(B.sup.1--Z.sup.1).sub.m1).sub.k-Q II* in which R.sup.a and
R.sup.b each, independently of one another, denote P, P-Sp-, H,
halogen, SF.sub.5, NO.sub.2, a carbyl group or hydrocarbyl group,
where at least one of the radicals R.sup.a and R.sup.b denotes
P-Sp-, P on each occurrence, identically or differently, denotes a
polymerizable group, Sp on each occurrence, identically or
differently, denotes a spacer group or a single bond, B.sup.1 and
B.sup.2 each, independently of one another, denote an aromatic,
heteroaromatic, alicyclic or heterocyclic group, which optionally
contains fused rings, and which is optionally mono- or
polysubstituted by L, Z.sup.1 on each occurrence, identically or
differently, denotes --O--, --S--, --CO--, --CO--O--, --OCO--,
--O--CO--O--, --OCH.sub.2--, --CH.sub.2O--, --SCH.sub.2--,
--CH.sub.2S--, --CF.sub.2O--, --OCF.sub.2--, --CF.sub.2S--,
--SCF.sub.2--, --(CH.sub.2).sub.n1--, --CF.sub.2CH.sub.2--,
--CH.sub.2CF.sub.2--, --(CF.sub.2).sub.n1--, --CH.dbd.CH--,
--CF.dbd.CF--, --C.ident.C--, --CH.dbd.CH--COO--,
--OCO--CH.dbd.CH--, CR.sup.0R.sup.00 or a single bond, L denotes P,
P-Sp-, H, OH, CH.sub.2OH, halogen, SF.sub.5, NO.sub.2, a carbyl
group or hydrocarbyl group, R.sup.0 and R.sup.00 each,
independently of one another, denote H or alkyl having 1 to 12 C
atoms, m1 denotes 0, 1, 2, 3 or 4, n1 denotes 1, 2, 3 or 4, R* on
each occurrence, identically or differently, denotes P, P-Sp-, H,
halogen, SF.sub.5, NO.sub.2, a carbyl group or hydrocarbyl group, Q
denotes a k-valent chiral group, which is optionally mono- or
poly-substituted by L, and k denotes 1, 2, 3, 4, 5 or 6.
27. A PS or PSA display according to claim 26, wherein in the
compounds of formula I* and II*, B.sup.1 and B.sup.2 each,
independently of one another, denote 1,4-phenylene,
naphthalene-1,4-diyl, naphthalen-2,6-diyl, phenanthrene-2,7-diyl,
anthracene-2,7-diyl, fluorene-2,7-diyl, coumarin, or flavon, in any
of which, one or more CH groups are optionally replaced by N,
cyclohexane-1,4-diyl, in which one or more non-adjacent CH.sub.2
groups are optionally replaced by O and/or S, 1,4-cyclohexenylene,
bicyclo[1.1.1]pentane-1,3-diyl, bicyclo[2.2.2]octane-1,4-diyl,
spiro[3.3]heptane-2,6-diyl, piperidine-1,4-diyl,
decahydronaphthalene-2,6-diyl,
1,2,3,4-tetrahydronaphthalene-2,6-diyl, indane-2,5-diyl,
octahydro-4,7-methanoindane-2,5-diyl, or phenanthrene-2,7-diyl,
wherein any of which is unsubstituted or mono- or polysubstituted
by L, L denotes P, P-Sp-, OH, CH.sub.2OH, F, Cl, Br, I, --CN,
--NO.sub.2, --NCO, --NCS, --OCN, --SCN,
--C(.dbd.O)N(R.sup.x).sub.2, --C(.dbd.O)Y.sup.1,
--C(.dbd.O)R.sup.x, --N(R.sup.x).sub.2, optionally substituted
silyl, optionally substituted aryl having 6 to 20 C atoms,
straight-chain or branched alkyl or alkoxy having 1 to 25 C atoms,
or straight-chain or branched alkenyl, alkinyl, alkylcarbonyl,
alkoxycarbonyl, alkylcarbonyloxy or alkoxycarbonyloxy having 2 to
25 C atoms, wherein in any of which one or more H atoms are
optionally replaced by F, Cl or P-Sp-, Y.sup.1 denotes halogen, and
R.sup.x denotes P, P-Sp-, H, halogen, straight-chain, branched or
cyclic alkyl having 1 to 25 C atoms, in which one or more
non-adjacent CH.sub.2 groups are optionally replaced by --O--,
--S--, --CO--, --CO--O--, --O--CO--, or --O--CO--O-- in such a way
that O and/or S atoms are not linked directly to one another, and
in which one or more H atoms are optionally replaced by F, Cl or
P-Sp-, an optionally substituted aryl or aryloxy group having 6 to
40 C atoms, or an optionally substituted heteroaryl or
heteroaryloxy group having 2 to 40 C atoms, wherein at least one of
the radicals R.sup.a, R.sup.b and L denotes P or P-Sp-.
28. A PS or PSA display according to claim 26, wherein a compound
of formula I* is of formulae I*1 to I*18 ##STR00228## ##STR00229##
in which P, Sp, L and Z.sup.1 on each occurrence, identically or
differently, are defined as for the compound of formula I*, R
denotes P, P-Sp-, H, halogen, straight-chain, branched or cyclic
alkyl having 1 to 25 C atoms, in which one or more non-adjacent
CH.sub.2 groups are optionally replaced by --O--, --S--, --CO--,
--CO--O--, --O--CO--, or --O--CO--O-- in such a way that O and/or S
atoms are not linked directly to one another, and in which one or
more H atoms are optionally replaced by F, Cl or P-Sp-, an
optionally substituted aryl or aryloxy group having 6 to 40 C
atoms, or an optionally substituted heteroaryl or heteroaryloxy
group having 2 to 40 C atoms, Z.sup.x denotes --O--, --CO-- or
CR.sup.yR.sup.z, R.sup.y and R.sup.z denote, independently of one
another, H, F, CH.sub.3 or CF.sub.3, L' and L'' have the meaning of
L for the compound of formula I*, m2 and m3 each, independently of
one another, denote an integer from 1 to 8, o denotes 0 or 1, r
denotes 0, 1, 2, 3 or 4, s denotes 0, 1, 2 or 3, t denotes 0, 1 or
2, and x denotes 0 or 1.
29. A PS or PSA display according to claim 28, wherein a compound
of formula I* is of formulae I*1 to I*15 and I*17 to I*18.
30. A PS or PSA display according to claim 26, wherein in formula
I*, P is a vinyloxy, acrylate, methacrylate, fluoroacrylate,
chloroacrylate, oxetane or epoxide group.
31. A PS or PSA display according to claim 26, wherein in formula
I*, Sp is Sp'-X', X' is --O--, --S--, --CO--, --COO--, --OCO--,
--O--COO--, --CO--NR.sup.0--, --NR.sup.0--CO--,
--NR.sup.0--CO--NR.sup.0-- or a single bond, Sp' is
--(CH.sub.2).sub.p1--,
--(CH.sub.2CH.sub.2O).sub.q1--CH.sub.2CH.sub.2--,
--CH.sub.2CH.sub.2--S--CH.sub.2CH.sub.2--,
--CH.sub.2CH.sub.2--NH--CH.sub.2CH.sub.2-- or
--(SiR.sup.0R.sup.00--O).sub.p1--, p1 is an integer from 1 to 12,
q1 is an integer from 1 to 3, and R.sup.0 and R.sup.00 each,
independently of one another, denote H or alkyl having 1 to 12 C
atoms.
32. A PS or PSA display according to claim 26, wherein a compound
of formula I* is of formulae RM-1 to RM-21 ##STR00230##
##STR00231## ##STR00232##
33. A PS or PSA display according to claim 16, wherein a compound
of formula I contains one or more rings ##STR00233##
34. A PS or PSA display according to claim 16, wherein the one or
more polymerizable compounds or reactive mesogens are
polymerized.
35. A PS or PSA display according to claim 16, wherein in formula
I, L.sup.1 and L.sup.2 denote F or Cl.
36. A PS or PSA display according to claim 16, wherein in formula
I, R.sup.1 is straight chain alkyl or alkoxy having 1 to 6 C atoms
or straight chain alkenyl having 2 to 6 C atoms.
37. A PS or PSA display, which PSA display is a PSA-VA, PS-IPS or
PS-FFS display, containing a display cell comprising two substrates
and two electrodes, wherein at least one substrate is transparent
to light and at least one substrate has one or two electrodes
provided thereon, and a layer of an LC medium comprising a
polymerized component and a low-molecular-weight component located
between the substrates, wherein the polymerized component is
obtainable by polymerization of one or more polymerizable compounds
between the substrates of the display cell in the LC medium,
optionally while applying a voltage to the electrodes, wherein the
low-molecular-weight component is an LC mixture, which has a
negative dielectric anisotropy and comprises one or more compounds
of formula I ##STR00234## in which ##STR00235## denote
independently of each other ##STR00236## R.sup.1 denotes alkyl or
alkenyl having 1 to 12 C atoms, in which one or two non-adjacent
CH.sub.2 groups are optionally replaced by --O--, --CH.dbd.CH--,
--CO--, --OCO-- or --COO-- in such a way that O atoms are not
linked directly to one another, R.sup.0 has one of the meanings
given for R.sup.1 or denotes X.sup.0, X.sup.0 is F, Cl, halogenated
alkyl or alkoxy having 1 to 6 C atoms, or halogenated alkenyl or
alkenyloxy having 2 to 6 C atoms, L.sup.1 and L.sup.2 each,
independently of one another, denote F, Cl, OCF.sub.3, CF.sub.3,
CH.sub.3, CH.sub.2F, CHF.sub.2, and p denotes 0.
38. A method for preparing a PS or PSA display, which PSA display
is a PSA-VA, PS-IPS or PS-FFS display, according to claim 37,
comprising providing an LC medium comprising one or more
polymerizable compounds and the LC mixture into a display cell
comprising two substrates and two electrodes, wherein at least one
substrate is transparent to light and at least one substrate has
one or two electrodes provided thereon, and polymerizing one or
more of the polymerizable compounds, optionally while applying a
voltage to the electrodes.
39. A method according to claim 38, wherein the polymerizable
compounds are polymerized by exposure to UV light having a
wavelength from 320 nm to 400 nm.
Description
[0001] The present invention relates to the use of LC
(liquid-crystal) compounds and LC media comprising them in LC
displays of the PS (polymer stabilised) or PSA (polymer sustained
alignment) type.
BACKGROUND OF THE INVENTION
[0002] The LC displays used at present are mostly those of the TN
(twisted nematic) type. However, these have the disadvantage of a
strong viewing-angle dependence of the contrast.
[0003] In addition, so-called VA (vertical alignment) displays are
known which have a broader viewing angle. The LC cell of a VA
display contains a layer of an LC medium between two transparent
electrodes, where the LC medium usually has a negative value of the
dielectric (DC) anisotropy. In the switched-off state, the
molecules of the LC layer are aligned perpendicular to the
electrode surfaces (homeotropically) or have a tilted homeotropic
alignment. On application of an electrical voltage to the
electrodes, a realignment of the LC molecules parallel to the
electrode surfaces takes place.
[0004] Furthermore, OCB (optically compensated bend) displays are
known which are based on a birefringence effect and have an LC
layer with a so-called "bend" alignment and usually positive (DC)
anisotropy. On application of an electrical voltage, a realignment
of the LC molecules perpendicular to the electrode surfaces takes
place. In addition, OCB displays normally contain one or more
birefringent optical retardation films in order to prevent
undesired transparency to light of the bend cell in the dark state.
OCB displays have a broader viewing angle and shorter response
times compared with TN displays.
[0005] Also known are IPS (in-plane switching) displays, which
contain an LC layer between two substrates, but wherein the two
electrodes are located only on one of the substrates, usually with
comb-shaped, interdigital structures. When applying a voltage to
the electrodes, an electric field which has a significant component
parallel to the LC layer is thereby generated. This causes
realignment of the LC molecules in the layer plane. Furthermore,
so-called FFS (fringe field switching) displays have been proposed
(see, inter alia, S. H. Jung et al., Jpn. J. Appl. Phys., Volume
43, No. 3, 2004, 1028), which likewise contain two electrodes on
the same substrate, but, in contrast to IPS displays, only one of
these is in the form of a structured (comb-shaped) electrode, and
the other electrode is unstructured. A strong, so-called "fringe
field" is thereby generated, i.e. a strong electric field close to
the edge of the electrodes, and, throughout the cell, an electric
field which has both a strong vertical component and a strong
horizontal component. Both IPS displays and also FFS displays have
a low viewing-angle dependence of the contrast.
[0006] In VA displays of the more recent type, uniform alignment of
the LC molecules is restricted to a plurality of relatively small
domains within the LC cell. Disclinations can exist between these
domains, also known as tilt domains. VA displays having tilt
domains have, compared with conventional VA displays, a greater
viewing-angle independence of the contrast and the grey shades. In
addition, displays of this type are simpler to produce since
additional treatment of the electrode surface for uniform alignment
of the molecules in the switched-on state, such as, for example, by
rubbing, is no longer necessary. Instead, the preferential
direction of the tilt or pretilt angle is controlled by a special
design of the electrodes. In so-called MVA (multidomain vertical
alignment) displays, this is usually achieved by the electrodes
having protrusions which cause a local pretilt. As a consequence,
the LC molecules are aligned parallel to the electrode surfaces in
different directions in different, defined regions of the cell on
application of a voltage. "Controlled" switching is thereby
achieved, and the formation of interfering disclination lines is
prevented. Although this arrangement improves the viewing angle of
the display, it results, however, in a reduction in its
transparency to light. A further development of MVA uses
protrusions on only one electrode side, while the opposite
electrode has slits, which improves the transparency to light. The
slitted electrodes generate an inhomogeneous electric field in the
LC cell on application of a voltage, meaning that controlled
switching is still achieved. For further improvement of the
transparency to light, the separations between the slits and
protrusions can be increased, but this in turn results in a
lengthening of the response times. In the so-called PVA (patterned
VA), protrusions are rendered completely superfluous in that both
electrodes are structured by means of slits on the opposite sides,
which results in increased contrast and improved transparency to
light, but is technologically difficult and makes the display more
sensitive to mechanical influences (tapping, etc.). For many
applications, such as, for example, monitors and especially TV
screens, however, a shortening of the response times and an
improvement in the contrast and luminance (transmission) of the
display are desired.
[0007] A further development are the so-called PS (polymer
sustained) or PSA (polymer sustained alignment) displays, also
known as "polymer stabilised" displays. In these, a small amount
(for example 0.3% by weight, typically <1% by weight) of a
polymerisable compound is added to the LC medium and, after
introduction into the LC cell, is polymerised or crosslinked in
situ, usually by UV photopolymerisation, optionally with an
electrical voltage applied between the electrodes. The addition of
polymerisable mesogenic or liquid-crystalline compounds, also known
as "reactive mesogens" (RMs), to the LC mixture has proven
particularly suitable.
[0008] In the meantime, the PS or PSA principle is being used in
diverse classical LC displays. Thus, for example, PSA-VA, PSA-OCB,
PS-IPS and PS-TN displays are known. In PSA-VA and PSA-OCB displays
polymerisation is usually carried out while a voltage is applied to
the electrodes, whereas in PSA-IPS displays polymerisation it is
carried out with or without, preferably without application of a
voltage. As can be demonstrated in test cells, the PSA method
results in a pretilt in the cell. In the case of PSA-OCB displays,
it is therefore possible for the bend structure to be stabilised so
that an offset voltage is unnecessary or can be reduced. In the
case of PSA-VA displays, this pretilt has a positive effect on
response times. For PSA-VA displays, a standard MVA or PVA pixel
and electrode layout can be used. In addition, however, it is
possible, for example, to manage with only one structured electrode
side and no protrusions, which significantly simplifies production
and at the same time results in very good contrast at the same time
as very good transparency to light.
[0009] PSA-VA displays are described, for example, in JP 10-036847
A, EP 1 170 626 A2, U.S. Pat. No. 6,861,107, U.S. Pat. No.
7,169,449, US 2004/0191428 A1, US 2006/0066793 A1 and US
2006/0103804 A1. PSA-OCB displays are described, for example, in
T.-J-Chen et al., Jpn. J. Appl. Phys. 45, 2006, 2702-2704 and S. H.
Kim, L.-C-Chien, Jpn. J. Appl. Phys. 43, 2004, 7643-7647. PS-IPS
displays are described, for example, in U.S. Pat. No. 6,177,972 and
Appl. Phys. Lett. 1999, 75(21), 3264. PS-TN displays are described,
for example, in Optics Express 2004, 12(7), 1221.
[0010] PSA displays, like the conventional displays described
above, can be operated either as active matrix or passive matrix
displays. In active matrix type displays the individual pixels are
usually addressed by integrated, non-linear active elements like
for example thin film transistors (TFT), in passive matrix type
displays by multiplexing, with both methods being well-known from
prior art.
[0011] In particular for monitor and especially TV applications,
optimisation of the response times, but also of the contrast and
luminance (i.e. also transmission) of the LC display, is still
demanded. The PSA process still appears to provide crucial
advantages here. In particular in the case of PSA-VA, a shortening
of the response times, which correlate with a measurable pretilt in
test cells, can be achieved without a significant adverse effects
on other parameters.
[0012] However, it has been found that the LC mixtures and RMs
known from the prior art still have some disadvantages on use in
PSA displays. Thus, not every desired soluble RM is also suitable
for PSA displays, and it often appears difficult to find more
suitable selection criteria than the direct PSA experiment with
pretilt measurements. The choice becomes even smaller if
polymerisation by means of UV light without the addition of
photoinitiators is desired, which may be advantageous for certain
applications.
[0013] In addition, the selected material system of LC mixture
(also referred to as "LC host mixture") and polymerisable component
should have the best possible electrical properties, in particular
a high "voltage holding ratio" (HR or VHR). A high HR after
irradiation with UV light is important especially for use in a PSA
display, because UV irradiation is an indispensable part of its
manufacturing process, although it can also occur as "normal"
stress in the finished display.
[0014] However, the problem arises that not every combination of LC
mixture and polymerisable component works is suitable for use in
PSA displays since, for example, an inadequate tilt or no tilt at
all is established or since, for example, the HR is inadequate for
TFT display applications.
[0015] In particular it is desired to have available novel and
improved materials for PSA displays which enable the generation of
a small pretilt. Especially desired are materials which will,
during polymerisation, either generate a smaller pretilt after the
same UV irradiation time as used for prior art materials, and/or
generate the same pretilt as the prior art materials already after
shorter exposure time. This allows to reduce the manufacturing time
(tact time) and the manufacturing costs for the display.
[0016] Another problem when manufacturing PSA displays ist the
presence and removal of unreacted RMs after the polymerisation step
used for tilt angle generation. Such unreacted RMs can negatively
affect the display properties and performance, for example by
uncontrolled polymerisation in the display during its
operation.
[0017] Thus, PSA displays of prior art often show the undesired
"image sticking" or "image burn" effect, wherein the image
generated in the display by addressing selected pixels remains
visible, even when the voltage for this pixel has been switched
off, or when other pixels have been addressed.
[0018] Image sticking can occur for example when using LC host
mixtures with a low HR, wherein the UV component of ambient light
or emitted by the display backlight can induce undesired cleavage
reactions in the LC molecules. This can lead to ionic impurities
which are enriched at the electrodes or alignment layers, where
they cause a reduction of the effective voltage applied to the
display. This effect is also known for conventional displays not
containing a polymeric component.
[0019] In PSA displays an additional image sticking effect can be
observed which is caused by the presence of residual unpolymerised
RMs. In such displays the UV component of ambient light or emitted
by the backlight causes undesired spontaneous polymerisation of the
unreacted RMs. In the addressed pixels this can change the tilt
angle after several addressing cycles, thereby causing a change of
the transmission, whereas in the unaddressed pixels the tilt angle
and transmission remain unaffected.
[0020] It is therefore desirable that the polymerisation reaction
when manufacturing the PSA display is as complete as possible, and
that the amount of residual unpolymerised RMs in the PSA display
after its manufacture is as low as possible.
[0021] For these purposes RMs and LC host mixtures are desired
which enable a complete and effective polymerisation reaction. In
addition it is desired to achieve a controlled polymerisation of
any residual amounts of unreacted RMs that are still present in the
display. Also, RMs and LC host mixtures are desired that enable a
faster and more effective polymerisation than the materials
currently known.
[0022] Another problem is that conventional RMs used for
manufacturing PSA displays by UV photopolymerisation often show
maximum UV absorption at short wavelengths, especially below 300
nm. However, in the manufacturing process of PSA displays it is
desired to avoid exposure to UV radiation of such short
wavelengths, because these "hard UV components" are hazardous and
increase the risk of damaging the various materials and components
used in the display. Therefore, display manufacturers preferably
use UV exposure systems of longer wavelengths, especially over 320
nm or even over 350 nm.
[0023] It is therefore desired to have available materials and
material combinations, especially RMs and LC host mixtures, for use
in PS or PSA displays, which are suitable to solve the
above-mentioned problems. In particular, the materials should
provide one or more of the following improvements: [0024] enable
effective polymerisation using longer UV wavelengths, especially of
320 nm or more, preferably 350 nm or more, [0025] provide better
protection against negative influence of the UV irradiation used
for photopolymerisation of the RMs, [0026] generally provide
improved UV stability, [0027] allow a faster and more effective
polymerisation reaction, [0028] reduce the amount of residual
unpolymerised RMs in the display, [0029] enable the faster
generation of small tilt angles and/or the generation of smaller
tilt angles compared to PSA displays and materials of prior art,
[0030] reduce the image sticking in the PSA display.
[0031] It was an aim of the present invention to provide novel PSA
displays and novel materials for use in PSA displays, in particular
LC host mixtures and RMs, which are suitable for solving the
above-mentioned problems, do not have the disadvantages described
above, or only do so to a smaller extent, and provide one or more
of the above-mentioned improvements and advantages.
[0032] In addition, the PSA displays should have high specific
resistance at the same time as a large working-temperature range,
short response times, even at low temperatures, and a low threshold
voltage, which facilitate a large number of grey shades, high
contrast and a wide viewing angle, and have high values for the HR
after UV exposure. In PSA displays for mobile applications, the LC
media should show low threshold voltage and high birefringence.
[0033] Surprisingly, it has now been found that these objects can
be achieved by using LC compounds, LC mixtures and LC media
according to the present invention as described hereinafter in PSA
displays. In particular, it has surprisingly been found that, when
using LC host mixtures containing specific terphenyl or
quaterphenyl compounds in combination with RMs, it is possible to
polymerise the RMS at higher wavelength and with UV radiation
dosage, provide improved protection against hazardous and damaging
UV light, enable photopolymerization with longer UV wavelengths,
and achieve photopolymerisation of the RMs that is faster, more
effective and more complete, compared to LC host mixtures of prior
art. Also, it enables a faster generation of the pretilt angle and
a reduction of the UV exposure time and/or UV intensity and/or UV
radiation dose, allowing a more time- and cost-effective
manufacturing process. Also, it allows to reduce the residual
amount of unreacted RMs and to suppress the image sticking
effect.
SUMMARY OF THE INVENTION
[0034] The invention relates to the use of compounds of formula
I,
##STR00001##
[0035] in which the individual radicals have the following
meanings
##STR00002##
[0036] denote independently of each other
##STR00003## [0037] R.sup.1 denotes alkyl or alkenyl having 1 to 12
C atoms, in which, in addition, one or two non-adjacent CH.sub.2
groups may be replaced by --O--, --CH.dbd.CH--, --CO--, --OCO-- or
--COO-- in such a way that O atoms are not linked directly to one
another, [0038] R.sup.0 has one of the meanings given for R.sup.1
or denotes X.sup.0, [0039] X.sup.0 is F, Cl, halogenated alkyl or
alkoxy having 1 to 6 C atoms, or halogenated alkenyl or alkenyloxy
having 2 to 6 C atoms, [0040] L.sup.1 and L.sup.2 each,
independently of one another, denote F, Cl, OCF.sub.3, CF.sub.3,
CH.sub.3, CH.sub.2F, CHF.sub.2, preferably F or Cl, most preferably
F, [0041] p denotes 0 or 1,
[0042] or of an LC mixture comprising one or more compounds of
formula I, in an LC medium that further contains one or
polymerisable compounds or RMs (reactive mesogens), preferably for
use in LC displays, very preferably for use in PS (polymer
sustained) or PSA (polymer sustained alignment) displays.
[0043] The invention further relates to an LC mixture comprising
one or more compounds of formula I, and to its use in LC displays,
especially in PS or PSA displays.
[0044] The invention further relates to an LC medium comprising one
or more compounds of formula I, or comprising an LC mixture
containing one or more compounds of formula I, and further
comprising one or polymerisable compounds or RMs, and to its use in
displays, especially in PS or PSA displays.
[0045] Especially preferred is an LC medium comprising [0046] a
polymerisable component A), comprising one or more polymerisable
compounds, preferably selected from RMs, and [0047] a liquid
crystal component B), preferably having a nematic phase, comprising
one or more compounds of formula I, preferably selected from LC
mixtures as described above and below.
[0048] The invention further relates to a method of preparing an LC
medium as described above and below, by mixing one or more
compounds of formula I with one or more polymerisable compounds or
RMs and optionally with one or more further liquid-crystalline
compounds and/or additives.
[0049] The invention further relates to an LC display comprising
one or more compounds of formula I, or an LC mixture or LC medium
comprising them, as described above and below, which is preferably
a PS or PSA display.
[0050] Especially preferred PS and PSA displays are PSA-VA,
PSA-OCB, PS-IPS, PS-FFS and PS-TN displays, very preferred PSA-VA
and PSA-IPS displays.
[0051] The invention further relates to an LC medium, its use in PS
and PSA displays, and to PS and PSA displays comprising it as
described above and below, wherein the polymerisable component(s)
or polymerisable compound(s) or RM(s) is(are) polymerised.
[0052] The invention further relates to the use of compounds of
formula I and LC mixtures comprising them, in an LC medium
comprising one or more polymerisable compounds, for the generation
of a pretilt angle in the LC medium by in situ polymerisation of
the polymerisable compound(s) under application of a voltage.
[0053] The invention further relates to a PS or PSA display
containing a display cell comprising two substrates and two
electrodes, wherein at least one substrate is transparent to light
and at least one substrate has one or two electrodes provided
thereon, and a layer of an LC medium comprising a polymerised
component and a low-molecular-weight component located between the
substrates, wherein the polymerised component is obtainable by
polymerisation of one or more polymerisable compounds between the
substrates of the display cell in the LC medium, preferably while
applying a voltage to the electrodes, and wherein the
low-molecular-weight component is an LC mixture comprising one or
more compounds of formula I as described above and below.
[0054] The invention further relates to a method of producing a PS
or PSA display as described above and below, by providing an LC
medium comprising one or more polymerisable compounds and an LC
mixture comprising one or more compounds of formula I as described
above and below into a display cell comprising two substrates and
two electrodes, wherein at least one substrate is transparent to
light and at least one substrate has one or two electrodes provided
thereon, and polymerising one or more of the polymerisable
compounds, preferably while applying a voltage to the
electrodes.
[0055] The PS and PSA displays of the present invention contain two
electrodes, preferably as transparent layers, wherein these two
electrodes are provided on one or both of the two substrates
forming the display cell.
[0056] Thus, either one electrode is provided on each of the two
substrates, for example in displays of the VA type, or the two
electrodes are both provided on one substrate and no electrode is
provided on the other substrate, for example in displays of the IPS
or FFS type.
DEFINITION OF TERMS
[0057] Unless stated otherwise, the term "PSA" is used above and
below for both PS and PSA displays.
[0058] The terms"tilt" and "tilt angle" refer to a tilted or
inclined orientation of the LC molecules in an LC mixture or LC
medium relative to the surface of the cell walls in an LC display.
The tilt angle herein means the average angle (<90.degree.)
between the molecular long axes of the LC molecules (LC director)
and the surface of the plane parallel substrates forming the LC
cell. A low value of the tilt angle (i.e. a large deviation from
90) herein corresponds to a large tilt. A suitable method for
measuring the tilt angle is described in the example section.
Unless stated otherwise, the tilt angle values as given above and
below refer to this measurement method.
[0059] The term "reactive mesogen" or "RM" denotes a compound
containing a mesogenic group and one or more functional groups
which are suitable for polymerisation (also known as polymerisable
group or group P).
[0060] The LC mixture or LC component B) as described above and
below, which contains the compounds of formula I and optionally
contains further liquid crystalline or mesogenic compounds, but
does not contain polymerisable or polymerised compounds, is
hereinafter also referred to as "(LC) host mixture or "(LC)
low-molecular-weight component".
[0061] The terms "low-molecular-weight" and "unpolymerisable"
denote compounds, usually monomeric, which do not contain any
functional group which is suitable for polymerisation under the
usual conditions known to the person skilled in the art, in
particular under the conditions applied during polymerisation of
the polymerisable compounds and RMs as used in the LC media of the
present invention.
[0062] The terms "nematic component" and "nematic LC mixture" as
used hereinafter mean an LC mixture which has a nematic LC phase,
but may in addition have other LC phases (like e.g. a smectic
phase), but very preferably means an LC mixture that has only a
nematic LC phase and no other LC phases.
[0063] The term "mesogenic group" is known to the person skilled in
the art and is described in the literature, and denotes a group
which, due to the anisotropy of its attracting and repelling
interactions, essentially contributes to causing a liquid-crystal
(LC) phase in low-molecular-weight or polymeric substances.
Compounds containing mesogenic groups ("mesogenic compounds") do
not necessarily have to have an LC phase themselves. It is also
possible for mesogenic compounds to exhibit LC phase behaviour only
after mixing with other compounds and/or after polymerisation.
Typical mesogenic groups are, for example, rigid rod- or
disc-shaped units. An overview of the terms and definitions used in
connection with mesogenic or LC compounds is given in Pure Appl.
Chem. 73(5), 888 (2001) and C. Tschierske, G. Pelzl, S. Diele,
Angew. Chem. 2004, 116, 6340-6368.
[0064] The term "spacer group", also referred to as "Sp", is known
to the person skilled in the art and is described in the
literature, see, for example, Pure Appl. Chem. 73(5), 888 (2001)
and C. Tschierske, G. Pelzl, S. Diele, Angew. Chem. 2004, 116,
6340-6368. Unless indicated otherwise, the terms "spacer group" or
"spacer" above and below denotes a flexible group which connects
the mesogenic group and the polymerisable group(s) to one another
in a polymerisable mesogenic compound or RM.
DETAILED DESCRIPTION OF THE INVENTION
[0065] The LC media for use in the PSA displays according to the
present invention contain one ore more polymerisable compounds or
RMs, which are preferably polymerisable by exposure to
photoradiation, very preferably UV radiation. In addition, the LC
media preferably contain an LC mixture comprising one or more
compounds of formula I and one or more further compounds selected
from mesogenic or liquid crystalline compounds, preferably selected
from nematic or nematogenic compounds. The LC mixture preferably
consists only of low-molecular-weight (i.e. monomeric or
unpolymerised) compounds, which are stable or unreactive to a
polymerisation reaction under the conditions used for the
polymerisation of the polymerisable compounds or RMs.
[0066] The polymerisable compounds are preferably selected from
RMs.
[0067] The LC host mixture is preferably a nematic LC mixture.
[0068] Preferably the LC media according to the present invention
do essentially consist of one or more polymerisable compounds and
an LC host mixture as described above and below. However, the LC
media or LC host mixtures may additionally comprise one or more
further components or additives, for example selected from chiral
dopants, polymerisation initiators, inhibitors, stabilizers,
surfactants, nanoparticles etc.
[0069] The concentration of the compounds of formula I in the LC
host mixture (i.e. without any polymerisable components) is
preferably from 0.1 to 30%, very preferably from 0.5 to 25%, most
preferably from 0.5 to 12%. Especially preferred are LC mixtures
containing from 0.5 to 5% of one compound of formula I, or LC
mixtures containing from 0.5 to 12% of two or more compounds of
formula I.
[0070] Especially preferred are LC mixtures containing 1 to 5,
preferably 1, 2 or 3 compounds of formula I.
[0071] The invention further relates to novel LC mixtures as
described above and below, which do not contain a polymerisable
compound, but do essentially consist of unpolymerisable or
low-molecular-weight compounds. These LC mixtures can be used in
classic displays of the VA type, like VA- and MVA-displays. The
invention further relates to LC displays, preferably VA and MVA
displays containing such an LC mixture.
[0072] The compounds of formula I, and the LC mixtures and LC media
comprising them are especially suitable for use in PS or PSA
displays, and in particular provide one or more of the following
improvements: [0073] PSA displays can be manufactured by using
longer UV wavelengths, preferably of 320 nm or more, very
preferably of 350 nm or more, [0074] one or more of the UV exposure
time, the UV radiation intensity, the UV radiation energy and the
UV radiation dose can be reduced, [0075] better protection against
negative influence of the UV irradiation used for
photopolymerisation of the RMs is provided, [0076] the overall UV
stability of the LC medium and the LC display are improved, [0077]
the polymerisation reaction can carried out faster and more
effective, and the extent of polymerisation of the RMS can be
increased, thereby also reducing the amount of residual
unpolymerised RMs in the display, [0078] the same small tilt angles
as in displays using materials of prior art can be generated
faster, and/or smaller tilt angles can be generated than in PSA
displays using materials of prior art, [0079] the image sticking in
the PSA display can be reduced.
[0080] It was also observed that the compounds of formula I in the
polymerisable LC media act like a sensitizer, by transferring the
UV radiation energy and activate the polymerisation of the RMs.
[0081] In addition, the LC media and LC mixtures of the present
invention have high specific resistance values and a good low
temperature stability (LTS) against undesired spontaneous
crystallization, and when used in PSA displays, exhibit adequate
tilt angles, even without the use of a photoinitiator. The LC
mixtures and LC media according to the present invention are also
advantageous as they show significantly lower threshold voltage and
a higher birefringence compared to displays comprising LC mixtures
as disclosed in prior art. They are therefore especially suitable
for use in displays for mobile applications.
[0082] A first preferred embodiment of the present invention
relates to a first sub-group consisting of compounds of formula I,
which comprise one or more rings selected from
##STR00004##
[0083] wherein L.sup.1 and L.sup.2 have the meanings given in
formula I, and wherein R.sup.0 denotes X.sup.0, and p is 0 or 1.
The compounds of this first sub-group preferably have a positive
dielectric anisotropy .DELTA..di-elect cons.>1.5.
[0084] Preferably in the compounds of this first sub-group the
rings
##STR00005##
[0085] are selected from the group consisting of the following
rings
##STR00006##
[0086] wherein L.sup.1 and L.sup.2 have the meanings given in
formula I.
[0087] Very preferably the compounds of this first sub-group
contain one or more rings
##STR00007##
[0088] and/or two or more rings
##STR00008##
[0089] wherein L.sup.1 and L.sup.2 have the meanings given in
formula I.
[0090] A second preferred embodiment of the present invention
relates to a second sub-group consisting of compounds of formula I,
which comprise one or more rings selected from
##STR00009##
[0091] wherein L.sup.1 and L.sup.2 have the meanings given in
formula I, and wherein R.sup.0 has one of the meanings of R.sup.1,
and p is 0 or 1, preferably 1. The compounds of this second
sub-group are dielectrically neutral, or more preferably have a
negative dielectric anisotropy .DELTA..di-elect cons.<-1.5.
[0092] Preferably in the compounds of this second sub-group the
rings
##STR00010##
[0093] are selected from the group consisting of the following
rings
##STR00011##
[0094] wherein L.sup.1 and L.sup.2 have the meanings given in
formula I.
[0095] Very preferably the compounds of this second sub-group
contain one or more rings
##STR00012##
[0096] and/or one or more rings
##STR00013##
[0097] and not more than one ring
##STR00014##
[0098] wherein L.sup.1 and L.sup.2 have the meanings given in
formula I.
[0099] Above and below, "dielectrically neutral" means compounds
having a dielectric anisotropy .DELTA..di-elect cons. from -1.5 to
+1.5,
[0100] Especially preferred are compounds of formula I and of the
preferred embodiments as described above and below, wherein [0101]
L.sup.1 and L.sup.2 denote F or Cl, preferably F, [0102] p is 0,
[0103] p is 1, [0104] R.sup.1 is straight chain alkyl or alkoxy
having 1 to 6 C atoms or straight chain alkenyl having 2 to 6 C
atoms, [0105] R.sup.0 has one of the meanings of R.sup.1, [0106]
R.sup.0 denotes X.sup.0, and is preferably selected from F, Cl,
CF.sub.3, CHF.sub.2, OCF.sub.3, OCHF.sub.2, OCFHCF.sub.3,
OCFHCHF.sub.2, OCFHCHF.sub.2, OCF.sub.2CH.sub.3,
OCF.sub.2CHF.sub.2, OCF.sub.2CHF.sub.2, OCF.sub.2CF.sub.2CHF.sub.2,
OCF.sub.2CF.sub.2CHF.sub.2, OCFHCF.sub.2CF.sub.3,
OCFHCF.sub.2CHF.sub.2, OCF.sub.2CF.sub.2CF.sub.3,
OCF.sub.2CF.sub.2CClF.sub.2, OCClFCF.sub.2CF.sub.3 or
CH.dbd.CF.sub.2, very preferably F or OCF.sub.3, most preferably
F.
[0107] The compounds of the first sub-group are preferably selected
from the group consisting of the following sub-formulae:
##STR00015##
[0108] wherein alkyl denotes a straight-chain alkyl radical with 1
to 6 C atoms, (O) denotes an O atom or a single bond, and X.sup.0
denotes F or OCF.sub.3, preferably F.
[0109] Especially preferred are compounds of formula IA1 and
IA2.
[0110] The compounds of the second sub-group are preferably
selected from group consisting of the following sub-formulae:
##STR00016## ##STR00017## ##STR00018##
[0111] in which R denotes a straight-chain alkyl or alkoxy radical
having 1-7 C atoms, R* denotes a straight-chain alkenyl radical
having 2-7 C atoms, (O) denotes an O atom or a single bond, and m
denotes an integer from 1 to 6. R* preferably denotes
CH.sub.2.dbd.CH--, CH.sub.2.dbd.CHCH.sub.2CH.sub.2--,
CH.sub.3--CH.dbd.CH--, CH.sub.3--CH.sub.2--CH.dbd.CH--,
CH.sub.3--(CH.sub.2).sub.2--CH.dbd.CH--,
CH.sub.3--(CH.sub.2).sub.3--CH.dbd.CH-- or
CH.sub.3--CH.dbd.CH--(CH.sub.2).sub.2--.
[0112] R preferably denotes methyl, ethyl, propyl, butyl, pentyl,
hexyl, methoxy, ethoxy, propoxy, butoxy or pentoxy.
[0113] Especially preferred are compounds of formula IB1, IB2,
IB21, IB22, and IB23, in particular those of formula IB2, IB21 and
IB23, wherein R is preferably straight-chain alkyl having 1-7 C
atoms and R* is preferably CH.sub.2.dbd.CHCH.sub.2CH.sub.2--.
[0114] Another preferred embodiment of the present invention
relates to an LC mixture, and an LC medium comprising said LC
mixture, wherein said LC mixture comprises [0115] one or more
compounds selected from the first sub-group as described above
(preferably compounds having positive .DELTA..di-elect cons.),
preferably in a concentration from 0.5 to 5%, and [0116] one or
more compounds selected from the second sub-group as described
above (preferably compounds being dielectrically neutral or having
negative .DELTA..di-elect cons.), preferably in a concentration
from 0.5 to 12%.
[0117] A preferred LC mixture according to this preferred
embodiment comprises one or more compounds selected from the group
consisting of formulae IA1-IA4, and one or more compounds selected
from the group consisting of formulae IB1-IB21.
[0118] A very preferred LC mixture according to this preferred
embodiment comprises one or more compounds of formula IA1, wherein
preferably X.sup.0 is F, and one or more compounds of formula IB2,
wherein preferably R is a straight-chain alkyl radical having 1-7 C
atoms and (O) is a single bond.
[0119] Another preferred embodiment of the present invention
relates to an LC medium comprising [0120] one or more polymerisable
compounds or RMs, and [0121] one or more compounds of formula I,
preferably wherein p is 1 (quaterphenyls), very preferably selected
from the first sub-group as described above (preferably compounds
with positive .DELTA..di-elect cons.), or an LC mixture containing
such compounds,
[0122] and to the use of such an LC medium in a process for
preparing a PSA display as described above and below, wherein the
polymerisable compounds are polymerised by irradiation with UV
light having a wavelength of 320 nm or more, preferably 330 nm or
more, very preferably 350 nm or more, and preferably 400 nm or
less.
[0123] This preferred process can be carried out for example by
using a band pass filter and/or a cut-off filter, which are
substantially transmissive for UV light with the respective desired
wavelength(s) and are substantially blocking light with the
respective undesired wavelengths. For example, when irradiation
with UV light of wavelengths .lamda. of 300-400 nm is desired, UV
exposure can be carried out using a wide band pass filter being
substantially transmissive for wavelengths 300 nm<.lamda.<400
nm. When irradiation with UV light of wavelength .lamda. of more
than 320 nm is desired, UV exposure can be carried out using a
cut-off filter being substantially transmissive for wavelengths
.lamda.>320 nm.
[0124] "Substantially transmissive" means that the filter transmits
a substantial part, preferably at least 50% of the intensity, of
incident light of the desired wavelength(s). "Substantially
blocking" means that the filter does not transmit a substantial
part, preferably at least 50% of the intensity, of incident light
of the undesired wavelengths. "Desired (undesired) wavelength" e.g.
in case of a band pass filter means the wavelengths inside
(outside) the given range of .lamda., and in case of a cut-off
filter means the wavelengths above (below) the given value of
.lamda..
[0125] This preferred process enables the manufacture of displays
by using longer UV wavelengths, thereby reducing or even avoiding
the hazardous and damaging effects of short UV light
components.
[0126] UV radiation energy is in general from 6 to 100 J, depending
on the production process conditions.
[0127] Especially preferred LC media and LC host mixtures are
indicated below: [0128] a) LC host mixture comprising one or more
compounds selected from the following formulae:
[0128] ##STR00019## [0129] wherein the individual radicals have the
following meanings [0130] a denotes 1 or 2, [0131] b denotes 0 or
1,
##STR00020##
[0131] denotes
##STR00021## [0132] R.sup.1 and R.sup.2 each, independently of one
another, denote alkyl or alkenyl having 1 to 12 C atoms, in which,
in addition, one or two non-adjacent CH.sub.2 groups may be
replaced by --O--, --CH.dbd.CH--, --CO--, --OCO-- or --COO-- in
such a way that O atoms are not linked directly to one another,
preferably alkyl or alkoxy having from 1 to 6 C atoms, [0133]
Z.sup.x and Z.sup.y each, independently of one another, denote
--CH.sub.2CH.sub.2--, --CH.dbd.CH--, --CF.sub.2O--, --OCF.sub.2--,
--CH.sub.2O--, --OCH.sub.2--, --CO--O--, --O--CO--,
--C.sub.2F.sub.4--, --CF.dbd.CF--, --CH.dbd.CH--CH.sub.2O --, or a
single bond, preferably a single bond, [0134] L.sup.1-4 each,
independently of one another, denote F, Cl, OCF.sub.3, CF.sub.3,
CH.sub.3, CH.sub.2F, CHF.sub.2, preferably F or Cl. [0135]
Especially preferably both L.sup.1 and L.sup.2 denote F, or one of
L.sup.1 and L.sup.2 denote F and the other denotes Cl. Further
preferably both L.sup.3 and L.sup.4 denote F, or one of L.sup.3 and
L.sup.4 denote F and the other denotes Cl. [0136] The compounds of
formula CY are preferably selected from the following
sub-formulae:
[0136] ##STR00022## ##STR00023## ##STR00024## [0137] in which a
denotes 1 or 2, alkyl and alkyl* each, independently of one
another, denote a straight-chain alkyl radical having 1-6 C atoms,
alkenyl denotes a straight-chain alkenyl radical having 2-6 C
atoms, and (O) denotes an O atom or a single bond. Alkenyl
preferably denotes CH.sub.2.dbd.CH--,
CH.sub.2.dbd.CHCH.sub.2CH.sub.2--, CH.sub.3--CH.dbd.CH--,
CH.sub.3--CH.sub.2--CH.dbd.CH--,
CH.sub.3--(CH.sub.2).sub.2--CH.dbd.CH--,
CH.sub.3--(CH.sub.2).sub.3--CH.dbd.CH-- or
CH.sub.3--CH.dbd.CH--(CH.sub.2).sub.2--. [0138] The compounds of
formula PY are preferably selected from the following
sub-formulae:
[0138] ##STR00025## ##STR00026## [0139] in which alkyl and alkyl*
each, independently of one another, denote a straight-chain alkyl
radical having 1-6 C atoms, alkenyl denotes a straight-chain
alkenyl radical having 2-6 C atoms, and (O) denotes an O atom or a
single bond. Alkenyl preferably denotes CH.sub.2.dbd.CH--,
CH.sub.2.dbd.CHCH.sub.2CH.sub.2--, CH.sub.3--CH.dbd.CH--,
CH.sub.3--CH.sub.2--CH.dbd.CH--,
CH.sub.3--(CH.sub.2).sub.2--CH.dbd.CH--,
CH.sub.3--(CH.sub.2).sub.3--CH.dbd.CH-- or
CH.sub.3--CH.dbd.CH--(CH.sub.2).sub.2--. [0140] b) LC host mixture
which comprises one or more compounds of the following formula:
[0140] ##STR00027## [0141] in which the individual radicals have
the following meanings:
##STR00028##
[0141] denotes
##STR00029##
##STR00030##
denotes
##STR00031## [0142] R.sup.3 and R.sup.4 each, independently of one
another, denote alkyl having 1 to 12 C atoms, in which, in
addition, one or two non-adjacent CH.sub.2 groups may be replaced
by --O--, --CH.dbd.CH--, --CO--, --OCO-- or --COO-- in such a way
that O atoms are not linked directly to one another, [0143] Z.sup.y
denotes --CH.sub.2CH.sub.2--, --CH.dbd.CH--, --CF.sub.2O--,
--OCF.sub.2--, --CH.sub.2O--, --OCH.sub.2--, --COO--, --OCO--,
--C.sub.2F.sub.4--, --CF.dbd.CF--, --CH.dbd.CHCH.sub.2O-- or a
single bond, preferably a single bond. [0144] The compounds of the
formula ZK are preferably selected from the following
sub-formulae:
[0144] ##STR00032## [0145] in which alkyl and alkyl* each,
independently of one another, denote a straight-chain alkyl radical
having 1-6 C atoms, and alkenyl denotes a straight-chain alkenyl
radical having 2-6 C atoms. Alkenyl preferably denotes
CH.sub.2.dbd.CH--, CH.sub.2.dbd.CHCH.sub.2CH.sub.2--,
CH.sub.3--CH.dbd.CH--, CH.sub.3--CH.sub.2--CH.dbd.CH--,
CH.sub.3--(CH.sub.2).sub.2--CH.dbd.CH--,
CH.sub.3--(CH.sub.2).sub.3--CH.dbd.CH-- or
CH.sub.3--CH.dbd.CH--(CH.sub.2).sub.2--. [0146] c) LC host mixture
which additionally comprises one or more compounds of the following
formula:
[0146] ##STR00033## [0147] in which the individual radicals have on
each occurrence, identically or differently, the following
meanings: [0148] R.sup.5 and R.sup.6 each, independently of one
another, have one of the meanings indicated above for R.sup.1,
##STR00034##
[0148] denotes
##STR00035##
denotes
##STR00036## [0149] and [0150] e denotes 1 or 2. [0151] The
compounds of the formula DK are preferably selected from the
following sub-formulae:
[0151] ##STR00037## [0152] in which alkyl and alkyl* each,
independently of one another, denote a straight-chain alkyl radical
having 1-6 C atoms, and alkenyl and alkenyl* each, independently of
one another, denote a straight-chain alkenyl radical having 2-6 C
atoms. Alkenyl and alkenyl* preferably denote CH.sub.2.dbd.CH--,
CH.sub.2.dbd.CHCH.sub.2CH.sub.2--, CH.sub.3--CH.dbd.CH--,
CH.sub.3--CH.sub.2--CH.dbd.CH--,
CH.sub.3--(CH.sub.2).sub.2--CH.dbd.CH--,
CH.sub.3--(CH.sub.2).sub.3--CH.dbd.CH-- or
CH.sub.3--CH.dbd.CH--(CH.sub.2).sub.2--. [0153] d) LC host mixture
which additionally comprises one or more compounds of the following
formula:
[0153] ##STR00038## [0154] in which the individual radicals have
the following meanings:
##STR00039##
[0154] denotes
##STR00040## [0155] f denotes 0 or 1, [0156] R.sup.1 and R.sup.2
each, independently of one another, denote alkyl having 1 to 12 C
atoms, in which, in addition, one or two non-adjacent CH.sub.2
groups may be replaced by --O--, --CH.dbd.CH--, --CO--, --OCO-- or
--COO-- in such a way that O atoms are not linked directly to one
another, [0157] Z.sup.x and Z.sup.y each, independently of one
another, denote --CH.sub.2CH.sub.2--, --CH.dbd.CH--, --CF.sub.2O--,
--OCF.sub.2--, --CH.sub.2O--, --OCH.sub.2--, --COO--, --OCO--,
--C.sub.2F.sub.4--, --CF.dbd.CF--, --CH.dbd.CHCH.sub.2O-- or a
single bond, preferably a single bond, [0158] L.sup.5 and L.sup.6
each, independently of one another, denote F, Cl, OCF.sub.3,
CF.sub.3, CH.sub.3, CH.sub.2F, CHF.sub.2. [0159] Preferably, both
radicals L.sup.5 and L.sup.6 denote F or one of the radicals
L.sup.5 and L.sup.6 denotes F and the other denotes Cl. [0160] The
compounds of the formula LY are preferably selected from the
following sub-formulae:
[0160] ##STR00041## ##STR00042## [0161] in which R.sup.1 has the
above-mentioned meaning, (O) denotes an O atom or a single bond,
alkyl denotes a straight-chain alkyl radical having 1-6 C atoms,
and v denotes an integer from 1 to 6. R.sup.1 preferably denotes
straight-chain alkyl having 1-6 C atoms or straight-chain alkenyl
having 2-6 C atoms, in particular CH.sub.3, C.sub.2H.sub.5,
n-C.sub.3H.sub.7, n-C.sub.4H.sub.9, n-C.sub.5H.sub.11,
CH.sub.2.dbd.CH--, CH.sub.2.dbd.CHCH.sub.2CH.sub.2--,
CH.sub.3--CH.dbd.CH--, CH.sub.3--CH.sub.2--CH.dbd.CH--,
CH.sub.3--(CH.sub.2).sub.2--CH.dbd.CH--,
CH.sub.3--(CH.sub.2).sub.3--CH.dbd.CH-- or
CH.sub.3--CH.dbd.CH--(CH.sub.2).sub.2--. The LC medium according to
the invention preferably comprises one or more compounds of the
above-mentioned formulae in amounts of >0 to .ltoreq.10% by
weight. [0162] e) LC host mixture which additionally comprises one
or more compounds selected from the following formulae:
[0162] ##STR00043## [0163] in which alkyl denotes C.sub.1-6-alkyl,
L.sup.x denotes H or F, and X denotes F, Cl, OCF.sub.3, OCHF.sub.2
or OCH.dbd.CF.sub.2. Particular preference is given to compounds of
the formula G1 in which X denotes F. [0164] f) LC host mixture
which additionally comprises one or more compounds selected from
the following formulae:
[0164] ##STR00044## ##STR00045## [0165] in which R.sup.5 has one of
the meanings indicated above for R.sup.1, alkyl denotes
C.sub.1-6alkyl, d denotes 0 or 1, and z and m each, independently
of one another, denote an integer from 1 to 6. R.sup.5 in these
compounds is particularly preferably C.sub.1-6-alkyl or -alkoxy or
C.sub.2-6-alkenyl, d is preferably 1. The LC medium according to
the invention preferably comprises one or more compounds of the
above-mentioned formulae in amounts of >0 to .ltoreq.10% by
weight. [0166] g) LC host mixture which additionally comprises one
or more biphenyl compounds of the following formulae:
[0166] ##STR00046## [0167] in which alkyl and alkyl* each,
independently of one another, denote a straight-chain alkyl radical
having 1-6 C atoms, and alkenyl and alkenyl* each, independently of
one another, denote a straight-chain alkenyl radical having 2-6 C
atoms. Alkenyl and alkenyl* preferably denote CH.sub.2.dbd.CH--,
CH.sub.2.dbd.CHCH.sub.2CH.sub.2--, CH.sub.3--CH.dbd.CH--,
CH.sub.3--CH.sub.2--CH.dbd.CH--,
CH.sub.3--(CH.sub.2).sub.2--CH.dbd.CH--,
CH.sub.3--(CH.sub.2).sub.3--CH.dbd.CH-- or
CH.sub.3--CH.dbd.CH--(CH.sub.2).sub.2--. [0168] The proportion of
the biphenyls of the formulae B1 to B3 in the LC mixture is
preferably at least 3% by weight, in particular .gtoreq.5% by
weight. [0169] The compounds of the formula B2 are particularly
preferred. [0170] The compounds of the formulae B1 to B3 are
preferably selected from the following sub-formulae:
[0170] ##STR00047## [0171] in which alkyl* denotes an alkyl radical
having 1-6 C atoms. The medium according to the invention
particularly preferably comprises one or more compounds of the
formulae B1a and/or B2c. [0172] h) LC host mixture which
additionally comprises one or more compounds of the following
formulae:
[0172] ##STR00048## [0173] in which R.sup.1 and R.sup.2 have the
above-mentioned meanings and preferably each, independently of one
another, denote straight-chain alkyl or alkenyl. [0174] Preferred
mixtures comprise one or more compounds selected from the formulae
O1, O3 and O4. [0175] i) LC host mixture which additionally
comprises one or more compounds of the following formula:
[0175] ##STR00049## [0176] in which
##STR00050##
[0176] denotes
##STR00051## [0177] R.sup.9 denotes H, CH.sub.3, C.sub.2H.sub.5 or
n-C.sub.3H.sub.7, (F) denotes an optional fluoro substituent, q
denotes 1, 2 or 3, and R.sup.7 has one of the meanings indicated
for R.sup.1, preferably in amounts of >3% by weight, in
particular .gtoreq.5% by weight and very particularly preferably
5-30% by weight. [0178] Particularly preferred compounds of the
formula FI are selected from the following sub-formulae:
[0178] ##STR00052## [0179] in which R.sup.7 preferably denotes
straight-chain alkyl having 1-6 C atoms, and R.sup.9 denotes
CH.sub.3, C.sub.2H.sub.5 or n-C.sub.3H.sub.7. Particular preference
is given to the compounds of the formulae FI1, FI2 and FI3. [0180]
k) LC host mixture which additionally comprises one or more
compounds of the following formulae:
[0180] ##STR00053## [0181] in which R.sup.8 has the meaning
indicated for R.sup.1, and alkyl denotes a straight-chain alkyl
radical having 1-6 C atoms. [0182] m) LC host mixture which
additionally comprises one or more compounds which contain a
tetrahydronaphthyl or naphthyl unit, such as, for example, the
compounds selected from the following formulae:
[0182] ##STR00054## ##STR00055## [0183] in which R.sup.10 and
R.sup.11 each, independently of one another, have one of the
meanings indicated for R.sup.1, preferably denote straight-chain
alkyl or straight-chain alkoxy having 1-6 C atoms or straight-chain
alkenyl having 2-6 C atoms, and Z.sup.1 and Z.sup.2 each,
independently of one another, denote --C.sub.2H.sub.4--,
--CH.dbd.CH--, --(CH.sub.2).sub.4--, --(CH.sub.2).sub.3O--,
--O(CH.sub.2).sub.3--, --CH.dbd.CHCH.sub.2CH.sub.2--,
--CH.sub.2CH.sub.2CH.dbd.CH--, --CH.sub.2O--, --OCH.sub.2--,
--COO--, --OCO--, --C.sub.2F.sub.4--, --CF.dbd.CF--, --CF.dbd.CH--,
--CH.dbd.CF--, --CH.sub.2-- or a single bond. [0184] n) LC host
mixture which additionally comprises one or more
difluoro-dibenzochromans and/or chromans of the following
formulae:
[0184] ##STR00056## [0185] in which R.sup.11 and R.sup.12 each,
independently of one another, have the above-mentioned meaning, and
c denotes 0 or 1, preferably in amounts of 3 to 20% by weight, in
particular in amounts of 3 to 15% by weight. [0186] Particularly
preferred compounds of the formulae BC and CR are selected from the
following sub-formulae:
[0186] ##STR00057## ##STR00058## [0187] in which alkyl and alkyl*
each, independently of one another, denote a straight-chain alkyl
radical having 1-6 C atoms, and alkenyl and alkenyl* each,
independently of one another, denote a straight-chain alkenyl
radical having 2-6 C atoms. Alkenyl and alkenyl* preferably denote
CH.sub.2.dbd.CH--, CH.sub.2.dbd.CHCH.sub.2CH.sub.2--,
CH.sub.3--CH.dbd.CH--, CH.sub.3--CH.sub.2--CH.dbd.CH--,
CH.sub.3--(CH.sub.2).sub.2--CH.dbd.CH--,
CH.sub.3--(CH.sub.2).sub.3--CH.dbd.CH-- or
CH.sub.3--CH.dbd.CH--(CH.sub.2).sub.2--. [0188] Very particular
preference is given to mixtures comprising one, two or three
compounds of the formula BC-2. [0189] o) LC host mixture which
additionally comprises one or more fluorinated phenanthrenes or
dibenzofurans of the following formulae:
[0189] ##STR00059## [0190] in which R.sup.11 and R.sup.12 each,
independently of one another, have the above-mentioned meanings, b
denotes 0 or 1, L denotes F, and r denotes 1, 2 or 3. [0191]
Particularly preferred compounds of the formulae PH and BF are
selected from the following sub-formulae:
[0191] ##STR00060## [0192] in which R and R' each, independently of
one another, denote a straight-chain alkyl or alkoxy radical having
1-7 C atoms. [0193] p) LC host mixture which comprises one or more,
preferably from 3 to 20 compounds of the formulae CY, PY and/or TY.
The proportion of these compounds in the host mixture as a whole is
preferably from 10 to 80% very preferably from 20 to 70%. The
content of these individual compounds is preferably in each case
from 2 to 25% by weight. [0194] q) LC host mixture or nematic
component wherein the compounds of formulae CY, PY and TY are
selected from the group consisting of formulae CY1, CY2, CY9, CY10,
PY1, PY2, PY9 and PY10. [0195] r) LC host mixture which comprises
one or more, preferably from 3 to 20 compounds of the formulae ZK
and DK. The proportion of these compounds in the host mixture as a
whole is preferably from 5 to 50% very preferably from 10 to 40%.
The content of an individual compound of these formulae is
preferably in each case from 2 to 20% by weight. [0196] s) LC host
mixture or nematic component wherein the compounds of formulae ZK
and DK are selected from the group consisting of formulae ZK1, ZK2,
ZK5, ZK6, DK1 and DK2. [0197] t) LC host mixture or nematic
component which comprises, in addition to the compounds of formula
I, one or more compounds that contain an alkenyl group, preferably
selected from the group consisting of formulae CY, PY, ZK and DK,
furthermore LY. In the preferred alkenyl-containing compounds of
formula CY, PY, ZK and DK, one or more of R.sup.1 and R.sup.2, or
of R.sup.3 and R.sup.4, or of R.sup.5 and R.sup.6, respectively,
denotes alkenyl having 2 to 12, preferably 2 to 6, C atoms. The
alkenyl group is preferably selected from the group consisting of
CH.sub.2.dbd.CH--, CH.sub.2.dbd.CHCH.sub.2CH.sub.2--,
CH.sub.3--CH.dbd.CH--, CH.sub.3--CH.sub.2--CH.dbd.CH--,
CH.sub.3--(CH.sub.2).sub.2--CH.dbd.CH--,
CH.sub.3--(CH.sub.2).sub.3--CH.dbd.CH-- and
CH.sub.3--CH.dbd.CH--(CH.sub.2).sub.2--. Especially preferred are
compounds selected from the group consisting of formulae ZK3, ZK4
and DK3. Further preferred are compounds selected from the group
consisting of formulae CY7, CY8, CY15, CY16, PY7, PY8, PY15, PY16.
Further preferred are compounds selected from the group consisting
of formulae B2, B3 and their subformulae. Further preferred are
compounds selected from the group consisting of formula LY and its
subformulae. The proportion of these compounds as a whole in the
host mixture is preferably from 2 to 70%, most preferably from 10
to 60%. The content of an individual compound of these formulae is
preferably from 2 to 50%. [0198] u) LC host mixture or nematic
component which comprises, in addition to the compounds of formula
I, one or more compounds selected from the group consisting of
formulae ZK3, ZK4 and DK3, most preferably wherein alkenyl denotes
CH.sub.2.dbd.CH--, CH.sub.2.dbd.CHCH.sub.2CH.sub.2--,
CH.sub.3--CH.dbd.CH--, CH.sub.3--CH.sub.2--CH.dbd.CH--,
CH.sub.3--(CH.sub.2).sub.2--CH.dbd.CH--,
CH.sub.3--(CH.sub.2).sub.3--CH.dbd.CH-- or
CH.sub.3--CH.dbd.CH--(CH.sub.2).sub.2--. The proportion of these
compounds as a whole in the host mixture is preferably from 2 to
70%, most preferably from 10 to 60%. The content of an individual
compound of these formulae is preferably from 2 to 50%. [0199] v)
LC medium which, apart from the polymerisable compounds as
described above and below, contains no compounds which contain a
terminal vinyloxy group (--O--CH.dbd.CH.sub.2). [0200] w) LC medium
which comprises 1 to 5, preferably 1, 2 or 3 polymerisable
compounds. [0201] x) LC medium in which the proportion of
polymerisable compounds in the medium as a whole is 0.05 to 5%,
preferably 0.1 to 1%. [0202] y) LC medium which comprises in
addition one or more, preferably low-molecular-weight and/or
unpolymerisable, chiral dopants, very preferably selected from
Table B, preferably in the concentration ranges given for Table
B.
[0203] The combination of compounds of the preferred embodiments
mentioned above with the polymerised compounds described above and
below effects low threshold voltages and very good low-temperature
stabilities with maintenance of high clearing points and high HR
values in the LC media according to the invention and allows a
pretilt angle to be set in PSA displays. In particular, the LC
media exhibit significantly shortened response times, in particular
also the grey-shade response times, in PSA displays compared with
the media from the prior art.
[0204] The LC host mixture preferably has a nematic phase range of
at least 80 K, particularly preferably at least 100 K, and a
rotational viscosity of not greater than 450 mPas, preferably not
greater than 350 mPas, at 20.degree. C.
[0205] The LC host mixture preferably has a negative dielectric
anisotropy .DELTA..di-elect cons., preferably of about -0.5 to
-7.5, in particular of about -2.5 to -6.0, at 20.degree. C. and 1
kHz.
[0206] The LC host mixture preferably has a birefringence
.DELTA.n>0.06, very preferably >0.09, most preferably
>0.12, and preferably has a birefringence .DELTA.n<0.20, very
preferably <0.18, most preferably <0.16.
[0207] The LC media may also comprise further additives known to
the person skilled in the art and described in the literature, like
for example polymerisation initiators, inhibitors, stabilizers,
surface active compounds or chiral dopants. These additives can be
polymerisable or unpolymerisable. Accordingly, polymerisable
additives will belong to the polymerisable component, and
unpolymerisable additives will belong to the nematic component of
the LC media.
[0208] The LC media can for example contain one or more chiral
dopants, which are preferably selected from the group consisting of
compounds from Table B below.
[0209] For example, 0 to 15% by weight of pleochroic dyes may be
added, furthermore nanoparticles, conductive salts, preferably
ethyldimethyldodecylammonium 4-hexoxybenzoate, tetrabutylammonium
tetraphenylborate or complex salts of crown ethers (cf., for
example, Haller et al., Mol. Cryst. Liq. Cryst. 24, 249-258
(1973)), may be added in order to improve the conductivity, or
substances may be added in order to modify the dielectric
anisotropy, the viscosity and/or the alignment of the nematic
phases. Substances of this type are described, for example, in DE-A
22 09 127, 22 40 864, 23 21 632, 23 38 281, 24 50 088, 26 37 430
and 28 53 728.
[0210] The individual components of the preferred embodiments of
the LC media according to the invention are either known or the
ways in which they are prepared can readily be derived from the
prior art by the person skilled in the relevant art since they are
based on standard methods described in the literature.
Corresponding compounds of the formula CY are described, for
example, in EP-A-0 364 538. Corresponding compounds of the formula
ZK are described, for example, in DE-A-26 36 684 and DE-A-33 21
373.
[0211] Preference is furthermore given to LC media comprising one,
two or three polymerisable compounds as described above and
below.
[0212] Preference is furthermore given to achiral polymerisable
compounds and LC media comprising, preferably consisting
exclusively of, achiral compounds.
[0213] Preference is furthermore given to PSA displays and LC media
in which the polymerisable component comprises one or more
polymerisable compounds containing a polymerisable group
(monoreactive) and one or more polymerisable compounds containing
two or more, preferably two, polymerisable groups (di- or
multireactive).
[0214] Preference is furthermore given to PSA displays and LC media
in which the polymerisable component consists exclusively of
polymerisable compounds containing two polymerisable groups
(direactive).
[0215] The polymerisable compounds can be added individually to the
LC media, but it is also possible to use mixtures comprising two or
more polymerisable compounds according to the invention. Copolymers
are formed on polymerisation of such mixtures. The invention
furthermore relates to the polymerisable mixtures mentioned above
and below. The polymerisable compounds are mesogenic or
non-mesogenic, preferably mesogenic or liquid-crystalline.
[0216] The proportion of the polymerisable component in the LC
media is preferably <5%, especially <1%, very preferably
<0.5%.
[0217] The proportion of the LC host mixture in the LC media is
preferably >95%, very preferably >99%.
[0218] In a preferred embodiment of the invention, the
polymerisable compounds are selected from formula I*
R.sup.a--B.sup.1--(Z.sup.1--B.sup.2).sub.m1--R.sup.b I*
[0219] in which the individual radicals have the following
meanings: [0220] R.sup.a and R.sup.b each, independently of one
another, denote P, P-Sp-, H, halogen, SF.sub.5, NO.sub.2, a carbyl
group or a hydrocarbyl group, [0221] P on each occurrence,
identically or differently, denotes a polymerisable group, [0222]
Sp on each occurrence, identically or differently, denotes a spacer
group or a single bond, [0223] B.sup.1 and B.sup.2 each,
independently of one another, denote an aromatic, heteroaromatic,
alicyclic or heterocyclic group, preferably having 4 to 25 ring
atoms, which may also contain fused rings, and which is optionally
mono- or polysubstituted by L, [0224] Z.sup.1 on each occurrence,
identically or differently, denotes --O--, --S--, --CO--,
--CO--O--, --OCO--, --O--CO--O--, --OCH.sub.2--, --CH.sub.2O--,
--SCH.sub.2--, --CH.sub.2S--, --CF.sub.2O--, --OCF.sub.2--,
--CF.sub.2S--, --SCF.sub.2--, --(CH.sub.2).sub.n1--,
--CF.sub.2CH.sub.2--, --CH.sub.2CF.sub.2--, --(CF.sub.2).sub.n1--,
--CH.dbd.CH--, --CF.dbd.CF--, --C.ident.C--, --CH.dbd.CH--COO--,
--OCO--CH.dbd.CH--, CR.sup.0R.sup.00 or a single bond, [0225] L
denotes P, P-Sp-, H, OH, CH.sub.2OH, halogen, SF.sub.5, NO.sub.2, a
carbyl group or hydrocarbyl group, [0226] R.sup.0 and R.sup.00
each, independently of one another, denote H or alkyl having 1 to
12 C atoms, [0227] m1 denotes 0, 1, 2, 3 or 4, [0228] n1 denotes 1,
2, 3 or 4,
[0229] wherein at least one of the radicals R.sup.a, R.sup.b and L
denotes or contains a group P or P-Sp-,
[0230] Particularly preferred compounds of the formula I* are those
in which [0231] B.sup.1 and B.sup.2 each, independently of one
another, denote 1,4-phenylene, naphthalene-1,4-diyl,
naphthalen-2,6-diyl, phenanthrene-2,7-diyl, anthracene-2,7-diyl,
fluorene-2,7-diyl, coumarin, flavon, in which, in addition, one or
more CH groups in these groups may be replaced by N,
cyclohexane-1,4-diyl, in which, in addition, one or more
non-adjacent CH.sub.2 groups may be replaced by O and/or S,
1,4-cyclohexenylene, bicyclo[1.1.1]pentane-1,3-diyl,
bicyclo[2.2.2]octane-1,4-diyl, spiro[3.3]heptane-2,6-diyl,
piperidine-1,4-diyl, decahydronaphthalene-2,6-diyl,
1,2,3,4-tetrahydronaphthalene-2,6-diyl, indane-2,5-diyl,
octahydro-4,7-methanoindane-2,5-diyl, or phenanthrene-2,7-diyl,
where all these groups may be unsubstituted or mono- or
polysubstituted by L, [0232] L denotes P, P-Sp-, OH, CH.sub.2OH, F,
Cl, Br, I, --CN, --NO.sub.2, --NCO, --NCS, --OCN, --SCN,
--C(.dbd.O)N(R.sup.x).sub.2, --C(.dbd.O)Y.sup.1,
--C(.dbd.O)R.sup.x, --N(R.sup.x).sub.2, optionally substituted
silyl, optionally substituted aryl having 6 to 20 C atoms,
straight-chain or branched alkyl or alkoxy having 1 to 25 C atoms,
or straight-chain or branched alkenyl, alkinyl, alkylcarbonyl,
alkoxycarbonyl, alkylcarbonyloxy or alkoxycarbonyloxy having 2 to
25 C atoms, wherein in all of these groups, in addition, one or
more H atoms may be replaced by F, Cl or P-Sp-, [0233] Y.sup.1
denotes halogen, [0234] R.sup.x denotes P, P-Sp-, H, halogen,
straight-chain, branched or cyclic alkyl having 1 to 25 C atoms, in
which, in addition, one or more non-adjacent CH.sub.2 groups may be
replaced by --O--, --S--, --CO--, --CO--O--, --O--CO--,
--O--CO--O-- in such a way that O and/or S atoms are not linked
directly to one another, and in which, in addition, one or more H
atoms may be replaced by F, Cl or P-Sp-, an optionally substituted
aryl or aryloxy group having 6 to 40 C atoms, or an optionally
substituted heteroaryl or heteroaryloxy group having 2 to 40 C
atoms,
[0235] where at least one of the radicals R.sup.a, R.sup.b and L
denotes P or P-Sp-.
[0236] Particular preference is given to compounds of the formula
I* in which one or both of the radicals R.sup.a and R.sup.b denote
P or P-Sp-.
[0237] Particularly preferred compounds of the formula I* are
selected from the following sub-formulae:
##STR00061## ##STR00062##
[0238] in which P, Sp, L and Z.sup.1 on each occurrence,
identically or differently, have one of the above-mentioned
meanings, P preferably denotes acrylate or methacrylate, and Sp
preferably denotes a single bond, [0239] R has one of the meanings
indicated for R.sup.x and preferably denotes P or P-Sp-, or
straight-chain or branched alkyl or alkoxy having 1 to 12 C atoms,
[0240] L is as defined above and preferably denotes F or CH.sub.3,
[0241] Z.sup.1 preferably denotes --COO--, --OCO-- or a single
bond, [0242] Z.sup.x denotes --O--, --CO-- or CR.sup.yR.sup.Z,
[0243] R.sup.y and R.sup.z denote independently of one another H,
F, CH.sub.3 or CF.sub.3, [0244] m2 and m3 each, independently of
one another, denote an integer from 1 to 8, [0245] o denotes 0 or
1, [0246] r denotes 0, 1, 2, 3 or 4, [0247] s denotes 0, 1, 2 or 3,
[0248] t denotes 0, 1 or 2, [0249] x denotes 0 or 1.
[0250] In a further preferred embodiment of the invention, the
polymerisable compounds are chiral compounds selected from formula
II*:
(R*--(B.sup.1--Z.sup.1).sub.m1).sub.k-Q II*
[0251] in which B.sup.1, Z.sup.1 and m1 have on each occurrence,
identically or differently, one of the meanings indicated in
formula I*, [0252] R* on each occurrence, identically or
differently, has one of the meanings indicated for R.sup.a in
formula I*, [0253] Q denotes a k-valent chiral group, which is
optionally mono- or polysubstituted by L, [0254] k is 1, 2, 3, 4, 5
or 6,
[0255] where the compounds contain at least one radical R* or L
which denotes or contains a group P-Sp- as defined above.
[0256] Particularly preferred compounds of the formula II* contain
a monovalent group Q of the formula III*
##STR00063##
[0257] in which L and r have on each occurrence, identically or
differently, the meanings indicated above, [0258] A* and B* each,
independently of one another, denote fused benzene, cyclohexane or
cyclohexene, [0259] t on each occurrence, identically or
differently, denotes 0, 1 or 2, and [0260] u on each occurrence,
identically or differently, denotes 0, 1 or 2.
[0261] Particular preference is given to groups of the formula III*
in which x denotes 1 or 2.
[0262] Further preferred compounds of the formula II* contain a
monovalent group Q or one or more groups R* of the formula IV*
##STR00064##
[0263] in which [0264] Q.sup.1 denotes alkylene or alkyleneoxy
having 1 to 9 C atoms or a single bond, [0265] Q.sup.2 denotes
optionally fluorinated alkyl or alkoxy having 1 to 10 C atoms, in
which, in addition, one or two non-adjacent CH.sub.2 groups may be
replaced by --O--, --S--, --CH.dbd.CH--, --CO--, --OCO--, --COO--,
--O--COO--, --S--CO--, --CO--S-- or --C.ident.C-- in such a way
that O and/or S atoms are not linked directly to one another,
[0266] Q.sup.3 denotes F, Cl, CN or alkyl or alkoxy as defined for
Q.sup.2, but different from Q.sup.2.
[0267] Preferred groups of the formula IV* are, for example,
2-butyl (=1-methyl-propyl), 2-methylbutyl, 2-methylpentyl,
3-methylpentyl, 2-ethylhexyl, 2-propylpentyl, in particular
2-methylbutyl, 2-methylbutoxy, 2-methylpentoxy, 3-methylpentoxy,
2-ethylhexoxy, 1-methylhexoxy, 2-octyloxy, 2-oxa-3-methylbutyl,
3-oxa-4-methylpentyl, 4-methylhexyl, 2-hexyl, 2-octyl, 2-nonyl,
2-decyl, 2-dodecyl, 6-methoxyoctoxy, 6-methyloctoxy,
6-methyloctanoyl-oxy, 5-methyl heptyloxycarbonyl,
2-methylbutyryloxy, 3-methylvaleroyloxy, 4-methylhexanoyloxy,
2-chloropropionyloxy, 2-chloro-3-methylbutyryloxy,
2-chloro-4-methylvaleryloxy, 2-chloro-3-methylvaleryloxy,
2-methyl-3-oxa-pentyl, 2-methyl-3-oxahexyl, 1-methoxypropyl-2-oxy,
1-ethoxypropyl-2-oxy, 1-propoxypropyl-2-oxy, 1-butoxypropyl-2-oxy,
2-fluorooctyloxy, 2-fluorodecyloxy, 1,1,1-trifluoro-2-octyloxy,
1,1,1-trifluoro-2-octyl, 2-fluoro-methyloctyloxy.
[0268] Further preferred compounds of the formula II* contain a
divalent group Q of the formula V*
##STR00065##
[0269] in which L, r, t, A* and B* have the meanings indicated
above.
[0270] Further preferred compounds of the formula II* contain a
divalent group Q selected from the following formulae:
##STR00066##
[0271] in which Phe denotes phenyl, which is optionally mono- or
polysubstituted by L, and R.sup.x denotes F or optionally
fluorinated alkyl having 1 to 4 C atoms.
[0272] Particularly preferred compounds of the formula II* are
selected from the following sub-formulae:
##STR00067## ##STR00068## ##STR00069##
[0273] in which L, P, Sp, m1, r and t have the meanings indicated
above, Z and A have on each occurrence, identically or differently,
one of the meanings indicated for Z.sup.1 and A.sup.1 respectively,
and t1 on each occurrence, identically or differently, denotes 0 or
1.
[0274] The chiral compounds of formula II* can be employed either
in optically active form, i.e. as pure enantiomers, or as any
desired mixture of the two enantiomers, or as the racemate thereof.
The use of the racemates is preferred. The use of the racemates has
some advantages over the use of pure enantiomers, such as, for
example, significantly more straightforward synthesis and lower
material costs.
[0275] Above and below, "carbyl group" denotes a mono- or
polyvalent organic group containing at least one carbon atom which
either contains no further atoms (such as, for example,
--C.ident.C--) or optionally contains one or more further atoms,
such as, for example, N, O, S, P, Si, Se, As, Te or Ge (for example
carbonyl, etc.). "Hydrocarbyl group" denotes a carbyl group which
additionally contains one or more H atoms and optionally one or
more heteroatoms, such as, for example, N, O, S, P, Si, Se, As, Te
or Ge. "Halogen" denotes F, Cl, Br or I.
[0276] A carbyl or hydrocarbyl group can be a saturated or
unsaturated group. Unsaturated groups are, for example, aryl,
alkenyl or alkynyl groups. A carbyl or hydrocarbyl radical having
more than 3 C atoms can be straight-chain, branched and/or cyclic
and may also have spiro links or condensed rings.
[0277] Above and below, the terms "alkyl", "aryl", "heteroaryl",
etc., also encompass polyvalent groups, for example alkylene,
arylene, heteroarylene, etc. The term "aryl" denotes an aromatic
carbon group or a group derived therefrom. The term "heteroaryl"
denotes "aryl" in accordance with the above definition containing
one or more heteroatoms.
[0278] Preferred carbyl and hydrocarbyl groups are optionally
substituted alkyl, alkenyl, alkynyl, alkoxy, alkylcarbonyl,
alkoxycarbonyl, alkylcarbonyloxy and alkoxycarbonyloxy having 1 to
40, preferably 1 to 25, particularly preferably 1 to 18 C atoms,
optionally substituted aryl or aryloxy having 6 to 40, preferably 6
to 25 C atoms, or optionally substituted alkylaryl, arylalkyl,
alkylaryloxy, arylalkyloxy, arylcarbonyl, aryloxycarbonyl,
arylcarbonyloxy and aryloxycarbonyloxy having 6 to 40, preferably 6
to 25 C atoms.
[0279] Further preferred carbyl and hydrocarbyl groups are
C.sub.1-C.sub.40 alkyl, C.sub.2-C.sub.40 alkenyl, C.sub.2-C.sub.40
alkynyl, C.sub.3-C.sub.40 allyl, C.sub.4-C.sub.40 alkyldienyl,
C.sub.4-C.sub.40 polyenyl, C.sub.6-C.sub.40 aryl, C.sub.6-C.sub.40
alkylaryl, C.sub.6-C.sub.40 arylalkyl, C.sub.6-C.sub.40
alkylaryloxy, C.sub.6-C.sub.40 arylalkyloxy, C.sub.2-C.sub.40
heteroaryl, C.sub.4-C.sub.40 cycloalkyl, C.sub.4-C.sub.40
cycloalkenyl, etc. Particular preference is given to
C.sub.1-C.sub.22 alkyl, C.sub.2-C.sub.22 alkenyl, C.sub.2-C.sub.22
alkynyl, C.sub.3-C.sub.22 allyl, C.sub.4-C.sub.22 alkyldienyl,
C.sub.6-C.sub.12 aryl, C.sub.6-C.sub.20 arylalkyl and
C.sub.2-C.sub.20 heteroaryl.
[0280] Further preferred carbyl and hydrocarbyl groups are
straight-chain, branched or cyclic alkyl radicals having 1 to 40,
preferably 1 to 25 C atoms, which are unsubstituted or mono- or
polysubstituted by F, Cl, Br, I or CN and in which one or more
non-adjacent CH.sub.2 groups may each be replaced, independently of
one another, by --C(R.sup.x).dbd.C(R.sup.x)--, --C.ident.C--,
--N(R.sup.x)--, --O--, --S--, --CO--, --CO--O--, --O--CO--,
--O--CO--O-- in such a way that O and/or S atoms are not linked
directly to one another.
[0281] R.sup.x preferably denotes H, halogen, a straight-chain,
branched or cyclic alkyl chain having 1 to 25 C atoms, in which, in
addition, one or more non-adjacent C atoms may be replaced by
--O--, --S--, --CO--, --CO--O--, --O--CO--, --O--CO--O--, and in
which one or more H atoms may be replaced by fluorine, an
optionally substituted aryl or aryloxy group having 6 to 40 C atoms
or an optionally substituted heteroaryl or heteroaryloxy group
having 2 to 40 C atoms.
[0282] Preferred alkyl groups are, for example, methyl, ethyl,
n-propyl, isopropyl, n-butyl, isobutyl, s-butyl, t-butyl,
2-methylbutyl, n-pentyl, s-pentyl, cyclo-pentyl, n-hexyl,
cyclohexyl, 2-ethylhexyl, n-heptyl, cycloheptyl, n-octyl,
cyclooctyl, n-nonyl, n-decyl, n-undecyl, n-dodecyl, dodecanyl,
trifluoro-methyl, perfluoro-n-butyl, 2,2,2-trifluoroethyl,
perfluorooctyl, perfluoro-hexyl, etc.
[0283] Preferred alkenyl groups are, for example, ethenyl,
propenyl, butenyl, pentenyl, cyclopentenyl, hexenyl, cyclohexenyl,
heptenyl, cycloheptenyl, octenyl, cyclooctenyl, etc.
[0284] Preferred alkynyl groups are, for example, ethynyl,
propynyl, butynyl, pentynyl, hexynyl, octynyl, etc.
[0285] Preferred alkoxy groups are, for example, methoxy, ethoxy,
2-methoxy-ethoxy, n-propoxy, i-propoxy, n-butoxy, i-butoxy,
s-butoxy, t-butoxy, 2-methylbutoxy, n-pentoxy, n-hexoxy,
n-heptyloxy, n-octyloxy, n-nonyloxy, n-decyloxy, n-undecyloxy,
n-dodecyloxy, etc.
[0286] Preferred amino groups are, for example, dimethylamino,
methylamino, methylphenylamino, phenylamino, etc.
[0287] Aryl and heteroaryl groups can be monocyclic or polycyclic,
i.e. they can have one ring (such as, for example, phenyl) or two
or more rings, which may also be fused (such as, for example,
naphthyl) or covalently linked (such as, for example, biphenyl), or
contain a combination of fused and linked rings. Heteroaryl groups
contain one or more heteroatoms, preferably selected from O, N, S
and Se.
[0288] Particular preference is given to mono-, bi- or tricyclic
aryl groups having 6 to 25 C atoms and mono-, bi- or tricyclic
heteroaryl groups having 2 to 25 C atoms, which optionally contain
fused rings and are optionally substituted. Preference is
furthermore given to 5-, 6- or 7-membered aryl and heteroaryl
groups, in which, in addition, one or more CH groups may be
replaced by N, S or O in such a way that O atoms and/or S atoms are
not linked directly to one another.
[0289] Preferred aryl groups are, for example, phenyl, biphenyl,
terphenyl, [1,1':3',1'']terphenyl-2'-yl, naphthyl, anthracene,
binaphthyl, phenanthrene, pyrene, dihydropyrene, chrysene,
perylene, tetracene, pentacene, benzo-pyrene, fluorene, indene,
indenofluorene, spirobifluorene, etc.
[0290] Preferred heteroaryl groups are, for example, 5-membered
rings, such as pyrrole, pyrazole, imidazole, 1,2,3-triazole,
1,2,4-triazole, tetrazole, furan, thiophene, selenophene, oxazole,
isoxazole, 1,2-thiazole, 1,3-thiazole, 1,2,3-oxadiazole,
1,2,4-oxadiazole, 1,2,5-oxadiazole, 1,3,4-oxadiazole,
1,2,3-thiadiazole, 1,2,4-thiadiazole, 1,2,5-thiadiazole,
1,3,4-thiadiazole, 6-membered rings, such as pyridine, pyridazine,
pyrimidine, pyrazine, 1,3,5-triazine, 1,2,4-triazine,
1,2,3-triazine, 1,2,4,5-tetrazine, 1,2,3,4-tetrazine,
1,2,3,5-tetrazine, or condensed groups, such as indole, iso-indole,
indolizine, indazole, benzimidazole, benzotriazole, purine,
naphth-imidazole, phenanthrimidazole, pyridimidazole,
pyrazinimidazole, quinoxalinimidazole, benzoxazole, naphthoxazole,
anthroxazole, phenanthroxazole, isoxazole, benzothiazole,
benzofuran, isobenzofuran, dibenzofuran, quinoline, isoquinoline,
pteridine, benzo-5,6-quinoline, benzo-6,7-quinoline,
benzo-7,8-quinoline, benzoisoquinoline, acridine, phenothiazine,
phenoxazine, benzopyridazine, benzopyrimidine, quinoxaline,
phenazine, naphthyridine, azacarbazole, benzocarboline,
phenanthridine, phenanthroline, thieno[2,3b]thiophene,
thieno[3,2b]thiophene, dithienothiophene, isobenzothiophene,
dibenzothiophene, benzothiadiazothiophene, or combinations of these
groups. The heteroaryl groups may also be substituted by alkyl,
alkoxy, thioalkyl, fluorine, fluoroalkyl or further aryl or
heteroaryl groups.
[0291] The (non-aromatic) alicyclic and heterocyclic groups
encompass both saturated rings, i.e. those which contain
exclusively single bonds, and also partially unsaturated rings,
i.e. those which may also contain multiple bonds. Heterocyclic
rings contain one or more heteroatoms, preferably selected from Si,
O, N, S and Se.
[0292] The (non-aromatic) alicyclic and heterocyclic groups can be
monocyclic, i.e. contain only one ring (such as, for example,
cyclohexane), or polycyclic, i.e. contain a plurality of rings
(such as, for example, decahydronaphthalene or bicyclooctane).
Particular preference is given to saturated groups. Preference is
furthermore given to mono-, bi- or tricyclic groups having 3 to 25
C atoms, which optionally contain fused rings and are optionally
substituted. Preference is furthermore given to 5-, 6-, 7- or
8-membered carbocyclic groups in which, in addition, one or more C
atoms may be replaced by Si and/or one or more CH groups may be
replaced by N and/or one or more non-adjacent CH.sub.2 groups may
be replaced by --O-- and/or --S--.
[0293] Preferred alicyclic and heterocyclic groups are, for
example, 5-membered groups, such as cyclopentane, tetrahydrofuran,
tetrahydrothiofuran, pyrrolidine, 6-membered groups, such as
cyclohexane, silinane, cyclohexene, tetrahydropyran,
tetrahydrothiopyran, 1,3-dioxane, 1,3-dithiane, piperidine,
7-membered groups, such as cycloheptane, and fused groups, such as
tetrahydronaphthalene, decahydronaphthalene, indane,
bicyclo[1.1.1]-pentane-1,3-diyl, bicyclo[2.2.2]octane-1,4-diyl,
spiro[3.3]heptane-2,6-diyl,
octahydro-4,7-methanoindane-2,5-diyl.
[0294] The aryl, heteroaryl, carbyl and hydrocarbyl radicals
optionally have one or more substituents, which are preferably
selected from the group comprising silyl, sulfo, sulfonyl, formyl,
amine, imine, nitrile, mercapto, nitro, halogen, C.sub.1-12 alkyl,
C.sub.6-12 aryl, C.sub.1-12 alkoxy, hydroxyl, or combinations of
these groups.
[0295] Preferred substituents are, for example,
solubility-promoting groups, such as alkyl or alkoxy,
electron-withdrawing groups, such as fluorine, nitro or nitrile, or
substituents for increasing the glass transition temperature (Tg)
in the polymer, in particular bulky groups, such as, for example,
t-butyl or optionally substituted aryl groups.
[0296] Preferred substituents, also referred to as "L" below, are,
for example, F, Cl, Br, I, --CN, --NO.sub.2, --NCO, --NCS, --OCN,
--SCN, --C(.dbd.O)N(R.sup.x).sub.2, --C(.dbd.O)Y.sup.1,
--C(.dbd.O)R.sup.x, --N(R.sup.x).sub.2, in which R.sup.x has the
above-mentioned meaning, and Y.sup.1 denotes halogen, optionally
substituted silyl or aryl having 6 to 40, preferably 6 to 20 C
atoms, and straight-chain or branched alkyl, alkoxy, alkylcarbonyl,
alkoxycarbonyl, alkylcarbonyloxy or alkoxycarbonyloxy having 1 to
25 C atoms, in which one or more H atoms may optionally be replaced
by F or Cl.
[0297] "Substituted silyl or aryl" preferably means substituted by
halogen, --CN, R.sup.0, --OR.sup.0, --CO--R.sup.0,
--CO--O--R.sup.0, --O--CO--R.sup.0 or --O--CO--O--R.sup.0, in which
R.sup.0 has the above-mentioned meaning.
[0298] Particularly preferred substituents L are, for example, F,
Cl, CN, NO.sub.2, CH.sub.3, C.sub.2H.sub.5, OCH.sub.3,
OC.sub.2H.sub.5, COCH.sub.3, COC.sub.2H.sub.5, COOCH.sub.3,
COOC.sub.2H.sub.5, CF.sub.3, OCF.sub.3, OCHF.sub.2,
OC.sub.2F.sub.5, furthermore phenyl.
##STR00070##
is preferably
##STR00071##
[0299] in which L has one of the above-mentioned meanings.
[0300] The polymerisable group P is a group which is suitable for a
polymerisation reaction, such as, for example, free-radical or
ionic chain polymerisation, polyaddition or polycondensation, or
for a polymer-analogous reaction, for example addition or
condensation onto a main polymer chain. Particular preference is
given to groups for chain polymerisation, in particular those
containing a C.dbd.C double bond or C.ident.C triple bond, and
groups which are suitable for polymerisation with ring opening,
such as, for example, oxetane or epoxide groups.
[0301] Preferred polymerisable groups are selected from the group
consisting of CH.sub.2.dbd.CW.sup.1--COO--,
CH.sub.2.dbd.CW.sup.1--CO--,
##STR00072##
CH.sub.2.dbd.CW.sup.2--(O).sub.k3--,
CW.sup.1.dbd.CH--CO--(O).sub.k3--, CW.sup.1.dbd.CH--CO--NH--,
CH.sub.2.dbd.CW.sup.1--CO--NH--, CH.sub.3--CH.dbd.CH--O--,
(CH.sub.2.dbd.CH).sub.2CH--OCO--,
(CH.sub.2.dbd.CH--CH.sub.2).sub.2CH--OCO--,
(CH.sub.2.dbd.CH).sub.2CH--O--,
(CH.sub.2.dbd.CH--CH.sub.2).sub.2N--,
(CH.sub.2.dbd.CH--CH.sub.2).sub.2N--CO--, HO--CW.sup.2W.sup.3--,
HS--CW.sup.2W.sup.3--, HW.sup.2N--, HO--CW.sup.2W.sup.3--NH--,
CH.sub.2.dbd.CW.sup.1--CO--NH--,
CH.sub.2.dbd.CH--(COO).sub.k1-Phe-(O).sub.k2--,
CH.sub.2.dbd.CH--(CO).sub.k1-Phe-(O).sub.k2--, Phe-CH.dbd.CH--,
HOOC--, OCN-- and W.sup.4W.sup.5W.sup.6Si--, in which W.sup.1
denotes H, F, Cl, CN, CF.sub.3, phenyl or alkyl having 1 to 5 C
atoms, in particular H, F, Cl or CH.sub.3, W.sup.2 and W.sup.3
each, independently of one another, denote H or alkyl having 1 to 5
C atoms, in particular H, methyl, ethyl or n-propyl, W.sup.4,
W.sup.5 and W.sup.6 each, independently of one another, denote Cl,
oxaalkyl or oxacarbonylalkyl having 1 to 5 C atoms, W.sup.7 and
W.sup.8 each, independently of one another, denote H, Cl or alkyl
having 1 to 5 C atoms, Phe denotes 1,4-phenylene, which is
optionally substituted by one or more radicals L as being defined
above but being different from P-Sp, and k.sub.1, k.sub.2 and
k.sub.3 each, independently of one another, denote 0 or 1, k.sub.3
preferably denotes 1, and k.sub.4 is an integer from 1 to 10.
[0302] Particularly preferred groups P are CH.sub.2.dbd.CH--COO--,
CH.sub.2.dbd.C(CH.sub.3)--COO--, CH.sub.2.dbd.CF--COO--,
CH.sub.2.dbd.CH--, CH.sub.2.dbd.CH--O--,
(CH.sub.2.dbd.CH).sub.2CH--OCO--,
(CH.sub.2.dbd.CH).sub.2CH--O--,
##STR00073##
in particular vinyloxy, acrylate, methacrylate, fluoroacrylate,
chloroacrylate, oxetane and epoxide.
[0303] In a further preferred embodiment of the invention, the
polymerisable compounds of the formulae I* and II* and sub-formulae
thereof contain, instead of one or more radicals P-Sp-, one or more
branched radicals containing two or more polymerisable groups P
(multifunctional polymerisable radicals). Suitable radicals of this
type, and polymerisable compounds containing them, are described,
for example, in U.S. Pat. No. 7,060,200 B1 or US 2006/0172090 A1.
Particular preference is given to multifunctional polymerisable
radicals selected from the following formulae:
--X-alkyl-CHP.sup.1--CH.sub.2--CH.sub.2P.sup.2 I*a
--X-alkyl-C(CH.sub.2P.sup.1)(CH.sub.2P.sup.2)--CH.sub.2P.sup.3
I*b
--X-alkyl-CHP.sup.1CHP.sup.2--CH.sub.2P.sup.3 I*c
--X-alkyl-C(CH.sub.2P.sup.1)(CH.sub.2P.sup.2)--C.sub.aaH.sub.2aa+1
I*d
--X-alkyl-CHP.sup.1--CH.sub.2P.sup.2 I*e
--X-alkyl-CHP.sup.1P.sup.2 I*f
--X-alkyl-CP.sup.1P.sup.2--C.sub.aaH.sub.2aa+1 I*g
--X-alkyl-C(CH.sub.2P.sup.1)(CH.sub.2P.sup.2)--CH.sub.2OCH.sub.2--C(CH.s-
ub.2P.sup.3)(CH.sub.2P.sup.4)CH.sub.2P.sup.5 I*h
--X-alkyl-CH((CH.sub.2).sub.aaP.sup.1)((CH.sub.2).sub.bbP.sup.2)
I*i
--X-alkyl-CHP.sup.1CHP.sup.2--C.sub.aaH.sub.2aa+1 I*k
[0304] in which [0305] alkyl denotes a single bond or
straight-chain or branched alkylene having 1 to 12 C atoms, in
which one or more non-adjacent CH.sub.2 groups may each be
replaced, independently of one another, by
--C(R.sup.x).dbd.C(R.sup.x)--, --C.ident.C--, --N(R.sup.x)--,
--O--, --S--, --CO--, --CO--O--, --O--CO--, --O--CO--O-- in such a
way that O and/or S atoms are not linked directly to one another,
and in which, in addition, one or more H atoms may be replaced by
F, Cl or CN, where R.sup.x has the above-mentioned meaning and
preferably denotes R.sup.0 as defined above,
[0306] aa and bb each, independently of one another, denote 0, 1,
2, 3, 4, 5 or 6, [0307] X has one of the meanings indicated for X',
and [0308] P.sup.1-5 each, independently of one another, have one
of the meanings indicated above for P.
[0309] Preferred spacer groups Sp are selected from the formula
Sp'-X', so that the radical "P-Sp-" conforms to the formula
"P-Sp'-X-", where [0310] Sp' denotes alkylene having 1 to 20,
preferably 1 to 12 C atoms, which is optionally mono- or
polysubstituted by F, Cl, Br, I or CN and in which, in addition,
one or more non-adjacent CH.sub.2 groups may each be replaced,
independently of one another, by --O--, --S--, --NH--,
--NR.sup.0--, --SiR.sup.0R.sup.00--, --CO--, --COO--, --OCO--,
--OCO--O--, --S--CO--, --CO--S--, --NR.sup.0--CO--O--,
--O--CO--NR.sup.0--, --NR.sup.0--CO--NR.sup.0--, --CH.dbd.CH-- or
--C.ident.C-- in such a way that O and/or S atoms are not linked
directly to one another, [0311] X' denotes --O--, --S--, --CO--,
--COO--, --OCO--, --O--COO--, --CO--NR.sup.0--, --NR.sup.0--CO--,
--NR.sup.0--CO--NR.sup.0--, --OCH.sub.2--, --CH.sub.2O--,
--SCH.sub.2--, --CH.sub.2S--, --CF.sub.2O--, --OCF.sub.2--,
--CF.sub.2S--, --SCF.sub.2--, --CF.sub.2CH.sub.2--,
--CH.sub.2CF.sub.2--, --CF.sub.2CF.sub.2--, --CH.dbd.N--,
--N.dbd.CH--, --N.dbd.N--, --CH.dbd.CR.sup.0--,
--CY.sup.2.dbd.CY.sup.3--, --C.ident.C--, --CH.dbd.CH--COO--,
--OCO--CH.dbd.CH-- or a single bond, [0312] R.sup.0 and R.sup.00
each, independently of one another, denote H or alkyl having 1 to
12 C atoms, and [0313] Y.sup.2 and Y.sup.3 each, independently of
one another, denote H, F, Cl or CN.
[0314] X' is preferably --O--, --S--, --CO--, --COO--, --OCO--,
--O--COO--, --CO--NR.sup.0--, --NR.sup.0--CO--,
--NR.sup.0--CO--NR.sup.0-- or a single bond.
[0315] Typical spacer groups Sp' are, for example,
--(CH.sub.2).sub.p1--,
--(CH.sub.2CH.sub.2O).sub.q1--CH.sub.2CH.sub.2--,
--CH.sub.2CH.sub.2--S--CH.sub.2CH.sub.2--,
--CH.sub.2CH.sub.2--NH--CH.sub.2CH.sub.2-- or
--(SiR.sup.0R.sup.00--O).sub.p1--, in which p1 is an integer from 1
to 12, q1 is an integer from 1 to 3, and R.sup.0 and R.sup.00 have
the above-mentioned meanings.
[0316] Particularly preferred groups --X'-Sp'- are
--(CH.sub.2).sub.p1--, --O--(CH.sub.2).sub.p1--,
--OCO--(CH.sub.2).sub.p1--, --OCOO--(OH.sub.2).sub.p1--.
[0317] Particularly preferred groups Sp' are, for example, in each
case straight-chain ethylene, propylene, butylene, pentylene,
hexylene, heptylene, octylene, nonylene, decylene, undecylene,
dodecylene, octadecylene, ethyleneoxyethylene,
methyleneoxybutylene, ethylenethioethylene,
ethylene-N-methyliminoethylene, 1-methylalkylene, ethenylene,
propenylene and butenylene.
[0318] The polymerisable compounds are prepared analogously to
processes known to the person skilled in the art and described in
standard works of organic chemistry, such as, for example, in
Houben-Weyl, Methoden der organischen Chemie [Methods of Organic
Chemistry], Thieme-Verlag, Stuttgart. The synthesis of
polymerisable acrylates and methacrylates of the formula I can be
carried out analogously to the methods described in U.S. Pat. No.
5,723,066. Further, particularly preferred methods are given in the
examples.
[0319] In the simplest case, the synthesis is carried out by
esterification or etherification of commercially available diols of
the general formula HO-A.sup.1-(Z.sup.1-A.sup.2).sub.m1-OH, in
which A.sup.1, A.sup.2, Z.sup.1 and m1 have the above-mentioned
meanings, such as, for example, 2,6-dihydroxynaphthalene
(naphthalene-2,6-diol), or 1-(4-hydroxyphenyl)phenyl-4-ol, using
corresponding acids, acid derivatives, or halogenated compounds
containing a group P, such as, for example, methacryloyl chloride
or methacrylic acid, in the presence of a dehydrating reagent, such
as, for example, DCC (dicyclohexylcarbodiimide).
[0320] The polymerisable compounds are polymerised or crosslinked
(if a compound contains two or more polymerisable groups) by
in-situ polymerisation in the LC medium between the substrates of
the LC display with application of a voltage. Suitable and
preferred polymerisation methods are, for example, thermal or
photopolymerisation, preferably photopolymerisation, in particular
UV photopolymerisation. If necessary, one or more initiators may
also be added here. Suitable conditions for the polymerisation, and
suitable types and amounts of initiators, are known to the person
skilled in the art and are described in the literature. Suitable
for free-radical polymerisation are, for example, the commercially
available photoinitiators Irgacure651.RTM., Irgacure184.RTM.,
Irgacure907.RTM., Irgacure369.RTM. or Darocure1173.RTM. (Ciba AG).
If an initiator is employed, its proportion in the mixture as a
whole is preferably 0.001 to 5% by weight, particularly preferably
0.001 to 1% by weight. However, the polymerisation can also take
place without addition of an initiator. In a further preferred
embodiment, the LC medium does not comprise a polymerisation
initiator.
[0321] The polymerisable component or the LC medium may also
comprise one or more stabilisers in order to prevent undesired
spontaneous polymerisation of the RMs, for example during storage
or transport. Suitable types and amounts of stabilisers are known
to the person skilled in the art and are described in the
literature. Particularly suitable are, for example, the
commercially available stabilisers of the Irganox.RTM. series (Ciba
AG). If stabilisers are employed, their proportion, based on the
total amount of RMs or polymerisable component A), is preferably
10-5000 ppm, particularly preferably 50-500 ppm.
[0322] The polymerisable compounds according to the invention are
also suitable for polymerisation without initiator, which is
associated with considerable advantages, such as, for example,
lower material costs and in particular less contamination of the LC
medium by possible residual amounts of the initiator or degradation
products thereof.
[0323] The polymerisable compounds according to the invention can
be added individually to the LC media, but it is also possible to
use mixtures comprising two or more polymerisable compounds. On
polymerisation of mixtures of this type, copolymers are formed. The
invention furthermore relates to the polymerisable mixtures
mentioned above and below.
[0324] The LC media which can be used in accordance with the
invention are prepared in a manner conventional per se, for example
by mixing one or more of the above-mentioned compounds with one or
more polymerisable compounds as defined above and optionally with
further liquid-crystalline compounds and/or additives. In general,
the desired amount of the components used in lesser amount is
dissolved in the components making up the principal constituent,
advantageously at elevated temperature. It is also possible to mix
solutions of the components in an organic solvent, for example in
acetone, chloroform or methanol, and to remove the solvent again,
for example by distillation, after thorough mixing. The invention
furthermore relates to the process for the preparation of the LC
media according to the invention.
[0325] It goes without saying to the person skilled in the art that
the LC media according to the invention may also comprise compounds
in which, for example, H, N, O, Cl, F have been replaced by the
corresponding isotopes.
[0326] The construction of the LC displays according to the
invention corresponds to the conventional geometry for PSA
displays, as described in the prior art cited at the outset.
Geometries without protrusions are preferred, in particular those
in which, in addition, the electrode on the colour filter side is
unstructured and only the electrode on the TFT side has slits.
Particularly suitable and preferred electrode structures for PSA-VA
displays are described, for example, in US 2006/0066793 A1.
[0327] Unless the context clearly indicates otherwise, as used
herein plural forms of the terms herein are to be construed as
including the singular form and vice versa.
[0328] Throughout the description and claims of this specification,
the words "comprise" and "contain" and variations of the words, for
example "comprising" and "comprises", mean "including but not
limited to", and are not intended to (and do not) exclude other
components.
[0329] It will be appreciated that variations to the foregoing
embodiments of the invention can be made while still falling within
the scope of the invention. Each feature disclosed in this
specification, unless stated otherwise, may be replaced by
alternative features serving the same, equivalent or similar
purpose. Thus, unless stated otherwise, each feature disclosed is
one example only of a generic series of equivalent or similar
features.
[0330] All of the features disclosed in this specification may be
combined in any combination, except combinations where at least
some of such features and/or steps are mutually exclusive. In
particular, the preferred features of the invention are applicable
to all aspects of the invention and may be used in any combination.
Likewise, features described in non-essential combinations may be
used separately (not in combination).
[0331] The following examples explain the present invention without
limiting it. However, they show the person skilled in the art
preferred mixture concepts with compounds preferably to be employed
and the respective concentrations thereof and combinations thereof
with one another. In addition, the examples illustrate which
properties and property combinations are accessible.
[0332] In the tables below the following abbreviations are
used:
[0333] (n, m, z: each, independently of one another, 1, 2, 3, 4, 5
or 6)
TABLE-US-00001 TABLE A ##STR00074## CCH-nm ##STR00075## CCH-nOm
##STR00076## CC-n-V ##STR00077## CC-n-V1 ##STR00078## CC-n-mV
##STR00079## PP-n-m ##STR00080## PP-n-Om ##STR00081## PP-n-Vm
##STR00082## PCH-nm ##STR00083## PCH-nOm ##STR00084## CY-n-Om
##STR00085## CY-n-m ##STR00086## CY-V-Om ##STR00087## CY-nV-(O)m
##STR00088## CVC-n-m ##STR00089## CVY-V-m ##STR00090## CEY-V-m
##STR00091## PY-n-(O)m ##STR00092## CCP-V-m ##STR00093## CCP-Vn-m
##STR00094## CCY-n-m ##STR00095## CCY-n-Om ##STR00096## CCY-V-m
##STR00097## CCY-Vn-m ##STR00098## CCY-V-Om ##STR00099## CCY-n-OmV
##STR00100## CCY-n-zOm ##STR00101## CCOC-n-m ##STR00102##
CPY-n-(O)m ##STR00103## CPY-V-Om ##STR00104## CQY-n-(O)m
##STR00105## CQIY-n-(O)m ##STR00106## CCQY-n-(O)m ##STR00107##
CCQIY-n-(O)m ##STR00108## CPQY-n-(O)m ##STR00109## CPQIY-n-Om
##STR00110## CLY-n-(O)m ##STR00111## CYLI-n-m ##STR00112## LYLI-n-m
##STR00113## LY-n-(O)m ##STR00114## PGIGI-n-F ##STR00115## PGP-n-m
##STR00116## PYP-n-(O)m ##STR00117## PYP-n-mV ##STR00118## YPY-n-m
##STR00119## YPY-n-mV ##STR00120## BCH-nm ##STR00121## BCH-nmF
##STR00122## CPYP-n-(O)m ##STR00123## CPGP-n-m ##STR00124##
CPYC-n-m ##STR00125## CYYC-n-m ##STR00126## CCYY-n-m ##STR00127##
CPYG-n-(O)m ##STR00128## CBC-nm ##STR00129## CBC-nmF ##STR00130##
CNap-n-Om ##STR00131## CCNap-n-Om ##STR00132## CENap-n-Om
##STR00133## CTNap-n-Om ##STR00134## CETNap-n-Om ##STR00135##
CK-n-F ##STR00136## DFDBC-n(O)-(O)m ##STR00137## C-DFDBF-n-(O)m
##STR00138## PGP-n-mV ##STR00139## PGU-n-F ##STR00140##
PPGU-n-F
[0334] In a preferred embodiment of the present invention, the LC
media according to the invention comprise one or more compounds
selected from the group consisting of compounds from Table A.
TABLE-US-00002 TABLE B TABLE B indicates possible dopants which can
be added to the LC media according to the invention. ##STR00141## C
15 ##STR00142## CB 15 ##STR00143## CM 21 ##STR00144## R/S-811
##STR00145## CM 44 ##STR00146## CM 45 ##STR00147## CM 47
##STR00148## CN ##STR00149## R/S-2011 ##STR00150## R/S-3011
##STR00151## R/S-4011 ##STR00152## R/S-5011 ##STR00153##
R/S-1011
[0335] The LC media preferably comprise 0 to 10% by weight, in
particular 0.01 to 5% by weight and particularly preferably 0.1 to
3% by weight, of dopants. The LC media preferably comprise one or
more dopants selected from the group consisting of compounds from
Table B.
TABLE-US-00003 TABLE C TABLE C indicates possible stabilisers which
can be added to the LC media according to the invention (n here
denotes an integer from 1 to 12, terminal methyl groups ar not
shown). ##STR00154## ##STR00155## ##STR00156## ##STR00157##
##STR00158## ##STR00159## ##STR00160## ##STR00161## ##STR00162##
##STR00163## ##STR00164## ##STR00165## ##STR00166## ##STR00167##
##STR00168## ##STR00169## ##STR00170## ##STR00171## ##STR00172##
##STR00173## ##STR00174## ##STR00175## ##STR00176## ##STR00177##
##STR00178## ##STR00179## ##STR00180## ##STR00181## ##STR00182##
##STR00183## ##STR00184## ##STR00185## ##STR00186## ##STR00187##
##STR00188##
[0336] The LC media preferably comprise 0 to 10% by weight, in
particular 1 ppm to 5% by weight and particularly preferably 1 ppm
to 3% by weight, of stabilisers. The LC media preferably comprise
one or more stabilisers selected from the group consisting of
compounds from Table C.
TABLE-US-00004 TABELLE D TABLE D indicates possible reactive
mesogens which can be used in the polymerizable component of LC
media according to the invention. ##STR00189## RM-1 ##STR00190##
RM-2 ##STR00191## RM-3 ##STR00192## RM-4 ##STR00193## RM-5
##STR00194## RM-6 ##STR00195## RM-7 ##STR00196## RM-8 ##STR00197##
RM-9 ##STR00198## RM-10 ##STR00199## RM-11 ##STR00200## RM-12
##STR00201## RM-13 ##STR00202## RM-14 ##STR00203## RM-15
##STR00204## RM-16 ##STR00205## RM-17 ##STR00206## RM-18
##STR00207## RM-19 ##STR00208## RM-20 ##STR00209## RM-21
[0337] The LC media preferably comprise one or more reactive
mesogens selected from the group consisting of compounds from Table
D.
[0338] In addition, the following abbreviations and symbols are
used: [0339] V.sub.o denotes threshold voltage, capacitive [V] at
20.degree. C., [0340] n.sub.e denotes extraordinary refractive
index at 20.degree. C. and 589 nm, [0341] n.sub.o denotes ordinary
refractive index at 20.degree. C. and 589 nm, [0342] .DELTA.n
denotes optical anisotropy at 20.degree. C. and 589 nm, [0343]
.di-elect cons..sub..perp. denotes the dielectric permittivity
perpendicular to the director at 20.degree. C. and 1 kHz, [0344]
.di-elect cons..parallel. denotes dielectric permittivity parallel
to the director at 20.degree. C. and 1 kHz, [0345] .DELTA..di-elect
cons.denotes dielectric anisotropy at 20.degree. C. and 1 kHz,
[0346] cl.p., T(N,I) denotes clearing point [.degree. C.], [0347]
.gamma..sub.1 denotes rotational viscosity at 20.degree. C. [mPas],
[0348] K.sub.1 denotes elastic constant, "splay" deformation at
20.degree. C. [pN], [0349] K.sub.2 denotes elastic constant,
"twist" deformation at 20.degree. C. [pN], [0350] K.sub.3 denotes
elastic constant, "bend" deformation at 20.degree. C. [pN], [0351]
LTS denotes low-temperature stability (phase), determined in test
cells, [0352] HR.sub.20 denotes voltage holding ratio at 20.degree.
C. [%], and [0353] HR.sub.100 denotes voltage holding ratio at
100.degree. C. [%].
[0354] Unless explicitly noted otherwise, all concentrations in the
present application are indicated in per cent by weight and relate
to the corresponding mixture or mixture component, unless
explicitly indicated otherwise.
[0355] Unless explicitly noted otherwise, all temperature values
indicated in the present application, such as, for example, the
melting point T(C,N), the transition from the smectic (S) to the
nematic (N) phase T(S,N) and the clearing point T(N,I), are
indicated in degrees Celsius (.degree. C.).
[0356] All physical properties are and have been determined in
accordance with "Merck Liquid Crystals, Physical Properties of
Liquid Crystals", Status November 1997, Merck KGaA, Germany, and
apply for a temperature of 20.degree. C., and .DELTA.n is
determined at 589 nm and .DELTA..di-elect cons. is determined at 1
kHz, unless explicitly indicated otherwise in each case.
[0357] For the present invention, the term "threshold voltage"
relates to the capacitive threshold (V.sub.0), also known as the
Freedericksz threshold, unless explicitly indicated otherwise. In
the examples, as is generally usual, the optical threshold for 10%
relative contrast (V.sub.10) may also be indicated.
[0358] The display used for measurement of the capacitive threshold
voltage has two plane-parallel outer plates at a separation of 4
.mu.m and electrode layers with overlying alignment layers of
rubbed polyimide on the insides of the outer plates, which cause a
homeotropic edge alignment of the liquid-crystal molecules.
[0359] The polymerisable compounds are polymerised in the display
by UV irradiation for a pre-determined time, with a voltage
simultaneously being applied to the display (usually 10 V to 30 V
alternating current, 1 kHz). In the examples, unless indicated
otherwise, a 25 mW/cm.sup.2 mercury vapour lamp was used, the
intensity was measured using a standard UV meter (model Ushio UNI
meter) fitted with a band-pass filter and/or cut-off filter
transmitting the desired UV wavelengths.
[0360] The tilt angle is determined by a rotational crystal
experiment (Autronic-Melchers TBA-105). A small value (i.e. a large
deviation from a 90.degree. angle) corresponds to a large tilt
here.
Example 1
[0361] The following nematic LC host mixture H1 is formulated:
TABLE-US-00005 CY-3-O2 15.00% Cl. p. +80.5 CY-5-O4 8.00% .DELTA.n
0.0909 CCY-3-O3 9.00% .DELTA..epsilon. -3.4 CCY-4-O2 5.50%
.epsilon..sub..parallel. 3.7 CPY-2-O2 9.00% .gamma..sub.1 138
CPY-3-O2 9.00% CCY-3-1 7.00% CCH-34 9.00% CCH-25 5.00% CCH-23
11.00% CCH-301 5.00% CCH-31 6.00% PPGU-3-F 1.00%
[0362] The mixture contains the compound PPGU-3-F of formula I
selected from the first sub-group (dielectrically positive) and
wherein p is 1.
Example 2
[0363] The following nematic LC host mixture H2 is formulated:
TABLE-US-00006 CY-3-O2 15.00% Cl. p. +80.5 CY-3-O4 10.00% .DELTA.n
0.0912 CCY-3-O2 6.50% .DELTA..epsilon. -3.3 CCY-3-O3 9.00%
.epsilon..sub..parallel. 4.2 CCY-4-O2 8.00% .gamma..sub.1 144
CPY-2-O2 8.50% CPY-3-O2 6.00% CCH-34 9.00% CCH-25 5.00% CCH-23
11.00% CCH-301 3.00% CCP-31 6.00% PGU-3-F 3.00%
[0364] The mixture contains the compound PGU-3-F of formula I
selected from the first sub-group (dielectrically positive) and
wherein p is 0.
Example 3
[0365] The following nematic LC host mixture H3 is formulated:
TABLE-US-00007 CY-3-O2 15.00% Cl. p. +80.0 CY-3-O4 5.50% .DELTA.n
0.0919 CCY-3-O3 9.00% .DELTA..epsilon. -3.3 CCY-4-O2 7.00%
.epsilon..sub..parallel. 3.5 CPY-2-O2 8.50% .gamma..sub.1 125
CPY-3-O2 9.00% CCY-3-1 3.00% CCH-34 9.00% CCH-25 5.00% CCH-23
11.00% CCH-301 9.00% CCP-31 6.00% PGP-2-2V 3.00%
[0366] The mixture contains compound PGP-2-2V of formula I selected
from the second sub-group (dielectrically neutral or negative) and
wherein p is 0.
Example 4
[0367] The following nematic LC host mixture H4 is formulated:
TABLE-US-00008 CY-3-O2 15.00% Cl. p. +80.0 CY-3-O4 5.50% .DELTA.n
0.0916 CCY-3-O3 9.00% .DELTA..epsilon. -3.3 CCY-4-O2 8.00%
.epsilon..sub..parallel. 3.5 CPY-2-O2 8.50% .gamma..sub.1 130
CPY-3-O2 9.00% CCY-3-1 3.00% CCH-34 9.00% CCH-25 5.00% CCH-23
11.00% CCH-301 9.00% CCP-31 5.00% PGP-2-3 3.00%
[0368] The mixture contains compound PGP-2-3 of formula I selected
from the second sub-group (dielectrically neutral or negative) and
wherein p is 0.
Example 5
[0369] The following nematic LC host mixture H5 is formulated:
TABLE-US-00009 CY-3-O2 15.00% Cl. p. +80.5 CY-3-O4 4.50% .DELTA.n
0.0915 CCY-3-O3 9.00% .DELTA..epsilon. -3.3 CCY-4-O2 7.00%
.epsilon..sub..parallel. 3.5 CPY-2-O2 9.00% .gamma..sub.1 130
CPY-3-O2 9.00% CCY-3-1 4.00% CCH-34 9.00% CCH-25 5.00% CCH-23
11.00% CCH-301 8.50% CCP-31 6.00% PYP-2-4 3.00%
[0370] The mixture contains compound PYP-2-4 of formula I selected
from the second sub-group (dielectrically neutral or negative) and
wherein p is 0.
Example 6
[0371] The following nematic LC host mixture H6 is formulated:
TABLE-US-00010 CY-3-O4 19.50% Cl. p. +79.5 CY-5-O2 10.00% .DELTA.n
0.1059 CCY-3-O2 11.00% .DELTA..epsilon. -5.0 CCY-3-O3 4.00%
.epsilon..sub..parallel. 4.1 CCY-4-O2 9.00% .gamma..sub.1 189
CPY-2-O2 10.00% CPY-3-O2 10.00% CCH-23 10.00% CCH-34 3.00% CCH-301
7.00% PYP-2-3 6.00% PPGU-3-F 0.50%
[0372] The mixture contains the compound PPGU-3-F of formula I
selected from the first sub-group (dielectrically positive) wherein
p is 1, and the compound PYP-2-3 of formula I selected from the
second sub-group (dielectrically neutral or negative) wherein p is
0.
[0373] To the nematic LC host mixture H6 0.20% of either the
reactive mesogen R1 or the reactive mesogen R4, respectively, as
shown below are added to form the polymerisable LC media M61 and
M64, respectively.
##STR00210##
[0374] The LC media M61 and M64 are filled into test cells prepared
as described above, and exposed to UV light (25 mW, 4 min) using a
wide band pass filter with 300 nm<.lamda.<400 nm, to
photopolymerise the reactive mesogen.
Example 7
[0375] The following nematic LC host mixture H7 is formulated:
TABLE-US-00011 CY-3-O4 19.00% Cl. p. +79.5 CY-5-O2 10.00% .DELTA.n
0.1135 CCY-3-O2 11.00% .DELTA..epsilon. -5.0 CCY-3-O3 3.00%
.epsilon..sub..parallel. 4.1 CCY-4-O2 8.50% .gamma..sub.1 198
CPY-2-O2 10.00% CPY-3-O2 10.00% CCH-23 10.50% CCH-301 7.50% PYP-2-3
10.00% PPGU-3-F 0.50%
[0376] The mixture contains the compound PPGU-3-F of formula I
selected from the first sub-group (dielectrically positive) wherein
p is 1, and the compound PYP-2-3 of formula I selected from the
second sub-group (dielectrically neutral or negative) wherein p is
0.
[0377] To the nematic LC host mixture H7 0.20% of the reactive
mesogen R1 are added to form the polymerisable LC medium M7. The LC
medium M7 is filled into a test cell prepared as described above,
and exposed to UV light (25 mW, 4 min) using a wide band pass
filter with 300 nm<.lamda.<400 nm, to photopolymerise the
reactive mesogen.
Example 8
[0378] The following nematic LC host mixture H8 is formulated:
TABLE-US-00012 CCH-35 7.00% Cl. p. +82.1 CCH-501 6.00% .DELTA.n
0.1030 CCY-2-1 5.00% .DELTA..epsilon. -3.4 CCY-3-1 5.00%
.epsilon..sub..parallel. 3.6 CCY-3-O2 10.00% .gamma..sub.1 184
CCY-5-O2 8.00% CPY-2-O2 12.50% CY-3-O4 12.50% CY-5-O4 12.50% PCH-53
10.00% BCH-32 6.00% BCH-52 6.00% PPGU-3-F 0.50%
[0379] The mixture contains the compound PPGU-3-F of formula I
selected from the first sub-group (dielectrically positive) wherein
p is 1.
[0380] To the nematic LC host mixture H8 0.30% of the reactive
mesogen R1 are added to form the polymerisable LC medium M8. The LC
medium M8 is filled into a test cell prepared as described above,
and exposed to UV light (25 mW, 4 min) using a wide band pass
filter with 300 nm<.lamda.<400 nm, to photopolymerise the
reactive mesogen.
Example 9
[0381] The following nematic LC host mixture H9 is formulated:
TABLE-US-00013 CC-3-V1 6.00% Cl. p. +105.2 CC-3-V 14.00% .DELTA.n
0.1265 CCPC-33 1.00% .DELTA..epsilon. -3.5 CCY-3-O2 7.00%
.epsilon..sub..parallel. 3.5 CCY-3-O3 7.50% .gamma..sub.1 189
CCY-4-O2 9.50% CPY-2-O2 11.00% CPY-3-O2 10.00% CY-3-O2 9.00%
CY-3-O4 2.50% PGP-2-3 2.50% PGP-2-4 6.00% PYP-2-3 7.50% CCH-34
4.00% CCH-35 2.50%
[0382] The mixture contains the compounds PGP-2-3, PGP-2-4 and
PYP-2-3 of formula I selected from the second sub-group
(dielectrically neutral or negative) wherein p is 0.
[0383] To the nematic LC host mixture H9 0.30% of the reactive
mesogen R1 are added to form the polymerisable LC medium M9. The LC
medium M9 is filled into a test cell prepared as described above,
and exposed to UV light (25 mW, 4 min) using a wide band pass
filter with 300 nm<.lamda.<400 nm, to photopolymerise the
reactive mesogen.
Example 10
[0384] The following nematic LC host mixture H10 is formulated:
TABLE-US-00014 CC-3-V1 6.50% Cl. p. +112.5 CC-3-V 12.50% .DELTA.n
0.1275 CCPC-33 2.00% .DELTA..epsilon. -3.5 CCPC-35 1.50%
.epsilon..sub..parallel. 3.5 CCY-3-O2 7.00% .gamma..sub.1 217
CCY-3-O3 7.00% CCY-4-O2 10.00% CPY-2-O2 10.00% CPY-3-O2 11.00%
CY-3-O2 10.00% CY-3-O4 2.00% PGP-2-3 4.00% PGP-2-4 6.00% PYP-2-3
5.00% CCH-34 1.50% CCH-35 4.00%
[0385] The mixture contains the compounds PGP-2-3, PGP-2-4 and
PYP-2-3 of formula I selected from the second sub-group
(dielectrically neutral or negative) wherein p is 0.
[0386] To the nematic LC host mixture H10 0.30% of the reactive
mesogen R1 are added to form the polymerisable LC medium M20. The
LC medium M10 is filled into a test cell prepared as described
above, and exposed to UV light (25 mW, 4 min) using a wide band
pass filter with 300 nm<.lamda.<400 nm, to photopolymerise
the reactive mesogen.
Comparative Example 1
[0387] The following nematic LC host mixture HC is formulated:
TABLE-US-00015 CY-3-O4 14.00% Cl. p. + 80.5 CCY-3-O2 9.00% .DELTA.n
0.0909 CCY-3-O3 9.00% .DELTA..epsilon. -3.4 CPY-2-O2 10.00%
.epsilon..sub..parallel. 3.7 CPY-3-O2 10.00% .gamma..sub.1 138
CCY-3-1 8.00% CCH-34 9.00% CCH-35 9.00% PCH-53 10.00% CCH-301 6.00%
CCH-303 9.00%
[0388] The mixture does not contain a compound of formula I
according to the present invention.
Use Example A
[0389] To each of the nematic LC host mixtures H1-H5 of Examples
1-5 and the nematic LC host mixture HC of comparative Example 6,
respectively, 0.20% of the reactive mesogen R1
##STR00211##
[0390] are added to give the polymerisable LC media M1-M5 and MC,
respectively.
[0391] The LC media M1-M5 and MC are filled into test cells
prepared as described above, and exposed to UV light (25 mW, 4 min)
using a wide band pass filter with 300 nm<.lamda.<400 nm, to
photopolymerise the reactive mesogen. The pretilt angle generated
in the LC host mixture after polymerisation is determined as
described above. The results are shown in Table 1 below.
TABLE-US-00016 TABLE 1 Mixture M1 M2 M3 M4 M5 MC Tilt
angle/.degree. 86.8 85.4 85.6 85.5 85.6 88.1
[0392] It can be seen that, in the LC media M1-M5 wherein the LC
host mixture contains a compound of formula I according to the
present invention, a smaller tilt angle was generated than in the
LC medium MC, wherein the LC host mixture does not contain a
compound of formula I.
Use Example B
[0393] The LC media M1-M5 of Example A are filled into test cells
and exposed to UV light as described in Use Example A, but using a
cut-off filter with .lamda.>320 nm instead of the band pass
filter, to photopolymerise the reactive mesogen. The pretilt angle
generated in the LC host mixture after polymerisation is determined
as described above. The results are shown in Table 2 below.
TABLE-US-00017 TABLE 2 Mixture M1 M2 M3 M4 M5 Tilt angle/.degree.
87.9 88.4 88.6 88.5 89.2
[0394] It can be seen that even with higher wavelengths a pretilt
angle can be generated. In LC medium M1, which contains a compound
of formula I wherein p is 1, the tilt angle from the vertical
direction is even larger than in LC media M2-M5 containing a
compound of formula I wherein p is 0.
[0395] This shows that the LC media according to the present
invention, especially those containing a compound of formula I
wherein p is 1, are also suitable for preparing PSA displays by
polymerisation at a longer UV wavelength.
Use Example C
[0396] To each of the nematic LC host mixtures H1, H4 and H5 of
Examples 1, 4 and 5, 0.20% of one of the reactive mesogens R1, R2
and R3 are added:
##STR00212##
[0397] In compound R1, both polymerizable functional groups are
attached directly to the mesogenic core. In compounds R2 and R3 one
of the polymerizable functional groups is attached to the mesogenic
core via a spacer group and the other is attached directly. The
compositions of the resulting polymerisable LC media M11-M53 are
shown in Table 3 below.
TABLE-US-00018 TABLE 3 Mixture M11 M12 M13 M41 M42 M43 M51 M52 M53
Host H1 H1 H1 H4 H4 H4 H5 H5 H5 (99.8%) RM R1 R2 R3 R1 R2 R3 R1 R2
R3 (0.2%)
[0398] The LC media M11-M53 are then filled into test cells as
described in Use Example A, and exposed to UV light (25 mW, 4 min)
using a wide band pass filter with 300 nm<.lamda.<400 nm, to
photopolymerise the reactive mesogen. The pretilt angle generated
in the LC host mixture after polymerisation is determined as
described above. The results are shown in Table 4 below.
TABLE-US-00019 TABLE 4 Mixture M11 M12 M13 M41 M42 M43 M51 M52 M53
Tilt 86.8 88.3 88.2 85.5 88.0 87.8 85.6 87.9 88.0
angle/.degree.
[0399] When comparing the effect of the reactive mesogen, it can be
seen that in the LC media M11, M41 and M51 containing the reactive
mesogen R1 (wihtou spacer groups) the smallest tilt angle is
generated, compared to the other LC media containing the reactive
mesogen R2 or R3.
[0400] When comparing the effect of the host mixture, it can be
seen that in the LC media M11, M12 and M13 containing the LC host
mixture H1 with a compound of formula I wherein p is 1, the
variation of the tilt angle when using different reactive mesogens
is smaller, compared to LC media containing the LC host mixture H4
or H5.
[0401] This shows that compounds of formula I wherein p is 1, and
LC media containing them, are especially suitable for preparing PSA
displays using reactive mesogens either with or without a spacer
group.
* * * * *