U.S. patent application number 13/513983 was filed with the patent office on 2012-09-27 for liquid-crystalline mixtures.
This patent application is currently assigned to BASF SE. Invention is credited to Jochen Brill, Thomas Musiol, Ulrich Schalkowsky.
Application Number | 20120241664 13/513983 |
Document ID | / |
Family ID | 43500312 |
Filed Date | 2012-09-27 |
United States Patent
Application |
20120241664 |
Kind Code |
A1 |
Brill; Jochen ; et
al. |
September 27, 2012 |
LIQUID-CRYSTALLINE MIXTURES
Abstract
The present invention describes liquid-crystalline mixtures, and
also oligomers or polymers which are obtainable by oligomerizing or
polymerizing the inventive liquid-crystalline mixtures, a process
for printing or coating substrates by applying and then
polymerizing the inventive liquid-crystalline mixtures and the use
of the inventive liquid-crystalline mixtures or of the inventive
oligomers or polymers for production of optical or electrooptical
components. The present invention further relates to the use of the
inventive liquid-crystalline mixtures which comprise at least one
chiral dopant for production of thermal insulation layers, and to
such thermal insulation layers.
Inventors: |
Brill; Jochen; (Speyer,
DE) ; Schalkowsky; Ulrich; (Speyer, DE) ;
Musiol; Thomas; (Maxdorf, DE) |
Assignee: |
BASF SE
Ludwigshafen
DE
|
Family ID: |
43500312 |
Appl. No.: |
13/513983 |
Filed: |
December 13, 2010 |
PCT Filed: |
December 13, 2010 |
PCT NO: |
PCT/EP2010/069475 |
371 Date: |
June 5, 2012 |
Current U.S.
Class: |
252/62 ;
252/299.5; 427/385.5 |
Current CPC
Class: |
G02B 1/04 20130101; F16L
59/028 20130101; C09K 19/2007 20130101; C09K 2019/0448 20130101;
C09K 2219/03 20130101; C09K 19/322 20130101 |
Class at
Publication: |
252/62 ;
252/299.5; 427/385.5 |
International
Class: |
C09K 19/58 20060101
C09K019/58; B05D 3/00 20060101 B05D003/00; E04B 1/78 20060101
E04B001/78 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 17, 2009 |
EP |
09179739.9 |
Claims
1. A liquid-crystalline mixture, comprising: (A) a compound of
formula I: ##STR00012## (B) a compound of formula II: ##STR00013##
(C) at least one compound selected from the group consisting of a
photoinitiator, a reactive diluent comprising a photopolymerizable
group, a diluent, a defoamer, a deaerator, a lubricant, a leveling
agent, a thermally curing auxiliary, a radiatively curing
auxiliary, a substrate wetting aids, a wetting aid, a dispersing
aid, a hydrophobizing agent, an adhesion promoter, a scratch
resistance auxiliary, and a chiral dopant, and (D) optionally at
least one substance selected from the group consisting of a dye and
a pigment, wherein Z.sup.1, Z.sup.2, Z.sup.3, and Z.sup.4 are each
independently ##STR00014## A.sup.1, A.sup.2, A.sup.3, and A.sup.4
are each independently a spacer having 4 to 8 carbon atoms,
Y.sup.1, Y.sup.2, Y.sup.3, and Y.sup.4 are each independently a
single chemical bond, oxygen, --CO--, --O--CO--, or --CO--O--,
R.sup.1 and R.sup.2 are each independently hydrogen,
C.sub.1-C.sub.6-alkyl, or CO--O--C.sub.1-C.sub.6-alkyl, a
proportion of component A is from 22.5 mol % to 32.5 mol % and a
proportion of component B is from 67.5 mol % to 77.5 mol %, based
on a total molar amount of A and B, and the proportions of
components A and B add up to 100 mol %
2. The liquid-crystalline mixture of claim 1, wherein
Z.sup.1-Y.sup.1, Y.sup.2-Z.sup.2, Z.sup.3-Y.sup.3, and
Y.sup.4-Z.sup.4 are each independently: ##STR00015##
3. An oligomer or polymer, obtained by a process comprising:
oligomerizing or polymerizing the mixture of claim 1.
4. A process for printing or coating a substrate, the process
comprising: applying the mixture of claim 1 to the substrate, and
then polymerizing the mixture.
5. A process for producing an optical or electrooptical component,
comprising: producing an optical or electrooptical component with
the mixture of claim 1.
6. A process for producing a thermal insulation layer, the process
comprising: producing the layer with the mixture of claim 1,
wherein the layer comprises a cholesteric layer capable of
reflecting at least 40% of infrared incident radiation, and
component (C) comprises a chiral dopant.
7. A process for producing a thermal insulation layer, the process
comprising: producing the layer with the mixture of claim 1,
wherein the layer comprises a cholesteric layer with a transmission
of at least 80% of incident radiation of wavelength of from 390 nm
to 750 nm.
8. A thermal insulation layer, comprising: a cholesteric layer,
capable of reflecting at least 40% of infrared incident radiation,
wherein the cholesteric layer is obtained by a process comprising
producing the cholesteric layer with the mixture of claim 1, and
component (C) comprises a chiral dopant.
9. A thermal insulation layer, comprising: a cholesteric layer with
a transmission of at least 80% of incident radiation of wavelength
of from 390 nm to 750 nm, wherein the cholesteric layer is obtained
by a process comprising producing the layer with the mixture of
claim 1, and wherein component (C) comprises a chiral dopant.
10. The process of claim 6, wherein the cholesteric layer is
capable of reflecting at least 45% of infrared incident
radiation.
11. The process of claim 6, wherein the cholesteric layer is
capable of reflecting at least 40% of incident radiation with
wavelength of from 750 to 2000 nm.
12. The process of claim 6, wherein the cholesteric layer is
capable of reflecting at least 45% of incident radiation with
wavelength of from 750 to 2000 nm.
13. The process of claim 7, wherein the cholesteric layer has a
transmission of at least 90% of incident radiation with wavelength
of from 390 nm to 750 nm.
14. The thermal insulation layer of claim 8, wherein the
cholesteric layer is capable of reflecting at least 45% of infrared
incident radiation.
15. The thermal insulation layer of claim 8, wherein the
cholesteric layer is capable of reflecting at least 40% of incident
radiation with wavelength of from 750 to 2000 nm.
16. The thermal insulation layer of claim 8, wherein the
cholesteric layer is capable of reflecting at least 45% of incident
radiation with wavelength of from 750 to 2000 nm.
17. The thermal insulation layer of claim 9, wherein the
cholesteric layer has a transmission of at least 90% of incident
radiation with wavelength of from 390 nm to 750 nm.
Description
[0001] The present invention describes liquid-crystalline mixtures,
and also oligomers or polymers which are obtainable by
oligomerizing or polymerizing the inventive liquid-crystalline
mixtures, a process for printing or coating substrates by applying
and then polymerizing the inventive liquid-crystalline mixtures and
the use of the inventive liquid-crystalline mixtures or of the
inventive oligomers or polymers for production of optical or
electrooptical components.
[0002] The present invention further relates to the use of the
inventive liquid-crystalline mixtures which comprise at least one
chiral dopant for production of thermal insulation layers, and to
such thermal insulation layers.
[0003] When heated, numerous compounds are not converted from the
crystalline state with defined short-range and long-range order of
the molecules directly to the liquid, unordered state, but rather
pass through a liquid-crystalline phase in which the molecules are
mobile but the molecule axes form an ordered structure. Elongated
molecules often form nematic liquid-crystalline phases which are
characterized by long-range orientation through parallel alignment
of the longitudinal axes of the molecules. When such a nematic
phase comprises chiral compounds or chiral molecular moieties, a
chiral nematic or cholesteric phase can form, which is
characterized by a helical superstructure. The lesser or greater
the proportion of chiral compound or chiral molecular moiety in a
given system, the greater or lesser is the pitch of the helical
superstructure. In order that electromagnetic radiation of
comparatively long wavelength, for example in the region of NIR
radiation, can be reflected to a sufficient degree, the formation
of maximum layer thicknesses of the chiral-nematic phase is
required, which, however, is typically associated with an increase
in the misorientation of the helical superstructure.
[0004] In addition, it is important for the application of the
liquid-crystalline materials that the liquid-crystalline phase is
within the required temperature range and has sufficient phase
width.
[0005] It was therefore an object of the present invention to
provide liquid-crystalline materials with comparatively high
birefringent properties, which are present in the
liquid-crystalline phase under the conditions of the application,
have a sufficiently high phase width and additionally permit the
production of low-defect layers even at relatively high layer
thicknesses.
[0006] Accordingly, liquid-crystalline mixtures have been found,
which comprise as component A:
one or more compounds of the general formula I
##STR00001##
in which the variables are defined as follows: Z.sup.1, Z.sup.2 are
each independently
##STR00002##
A.sup.1, A.sup.2 are each independently spacers having 4 to 8
carbon atoms, Y.sup.1, Y.sup.2 are each independently a chemical
single bond, oxygen, --CO--, --O--CO-- or --CO--O--, R.sup.1 is
hydrogen, C.sub.1-C.sub.6-alkyl or CO--O--C.sub.1-C.sub.6-alkyl, as
component B: one or more compounds of the general formula II
##STR00003##
in which the variables are defined as follows: Z.sup.3, Z.sup.4 are
each independently
##STR00004##
A.sup.3, A.sup.4 are each independently spacers having 4 to 8
carbon atoms, Y.sup.3, Y.sup.4 are each independently a chemical
single bond, oxygen, --CO--, --O--CO-- or --CO--O--, R.sup.2 is
hydrogen, C.sub.1-C.sub.6-alkyl or CO--O--C.sub.1-C.sub.6-alkyl,
where the proportion of component A is 22.5 mol % to 32.5 mol % and
the proportion of component B is 67.5 mol % to 77.5 mol %, based on
the total molar amount of A and B, and the proportions of
components A and B add up to 100 mol %, and as component C: one or
more substances selected from the group consisting of: C.1
photoinitiators; C.2 reactive diluents which comprise
photopolymerizable groups; C.3 solvents; C.4 defoamers and
deaerators; C.5 lubricants and leveling agents; C.6 thermally
curing and/or radiatively curing auxiliaries; C.7 substrate wetting
aids; C.8 wetting and dispersing aids; C.9 hydrophobizing agents;
C.10 adhesion promoters; C.11 auxiliaries for improving scratch
resistance; and C.12 chiral dopants, and optionally as component D:
one or more substances selected from the group consisting of: D.1
dyes; and D.2 pigments.
[0007] Preferably, the Z.sup.1 and Z.sup.2 radicals in formula I
and the Z.sup.3 and Z.sup.4 radicals in formula II are the same.
More particularly, all Z.sup.1 to Z.sup.4 radicals are vinyl
groups.
[0008] Preference is given to liquid-crystalline mixtures in which
Z.sup.1-Y.sup.1 and Y.sup.2-Z.sup.2 in formula I of component A and
Z.sup.3-Y.sup.3 and Y.sup.4-Z.sup.4 in formula II of component B
are reactive moieties
##STR00005##
[0009] More particularly, the Z.sup.1-Y.sup.1 and Y.sup.2-Z.sup.2
and Z.sup.3-Y.sup.3 and Y.sup.4-Z.sup.4 moieties are each the same
as one another. More preferably, all Z.sup.1-Y.sup.1,
Y.sup.2-Z.sup.2, Z.sup.3-Y.sup.3 and Y.sup.4-Z.sup.4 moieties are
acryloyloxy groups.
[0010] The spacers A.sup.1 and A.sup.2 comprise 4 to 8 carbon atoms
and consist of predominantly linear aliphatic groups. They may be
interrupted in the chain by nonadjacent oxygen atoms. Possible
substituents for the spacer chain include, for example, fluorine,
chlorine, bromine, cyano, methyl and ethyl.
[0011] The spacers A.sup.1 and A.sup.2, and A.sup.3 and A.sup.4,
are preferably each the same as one another.
[0012] Representative unsubstituted spacers A.sup.1, A.sup.2,
A.sup.3 and A.sup.4 are, for example:
--(CH.sub.2).sub.p-- or
--(CH.sub.2CH.sub.2O).sub.mCH.sub.2CH.sub.2--;
representative substituted spacers A.sup.1, A.sup.2, A.sup.3 and
A.sup.4 are, for example:
##STR00006##
where p represents integers of 4 to 8, m represents integers of 1
to 3, and q represents integers of 3 to 7.
[0013] C.sub.1-C.sub.6-Alkyl in the definition of the R.sup.1 and
R.sup.2 radicals or in the CO--O--C.sub.1-C.sub.6-alkyl moieties in
the definition of the R.sup.1 and R.sup.2 radicals in the formulae
I and II are understood to mean methyl, ethyl, propyl, isopropyl,
butyl, isobutyl, sec-butyl, tert-butyl, pentyl, isopentyl,
neopentyl, tert-pentyl, hexyl and 2-methylpentyl. The
C.sub.3-C.sub.6-alkyl radicals are preferably unbranched. Preferred
radicals are methyl, ethyl, propyl, butyl, pentyl and hexyl.
[0014] The preparation of the compounds of the general formula I of
component A is described, for example, in the publication WO
97/00600 A2; the preparation of the compounds of the general
formula II of component B is described, for example, in the
publication WO 2006/120220 A1.
[0015] When the inventive liquid-crystalline mixtures are to be
photochemically polymerized, commercial photoinitiators are
typically added thereto as component C.1. For curing by electron
beams, such photoinitiators, however, are generally
unnecessary.
[0016] Suitable photoinitiators C.1 are, for example, isobutyl
benzoin ether, 2,4,6-trimethylbenzoyldiphenylphosphine oxide,
1-hydroxycyclohexyl phenyl ketone,
2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)furan-1-one,
mixtures of benzophenone and 1-hydroxycyclohexyl phenyl ketone,
2,2-dimethoxy-2-phenylacetophenone, perfluorinated
diphenyltitanocenes,
2-methyl-1-(4-[methylthio]-phenyl)-2-(4-morpholinyl)-1-propanone,
2-hydroxy-2-methyl-1-phenylpropan-1-one, 4-(2-hydroxyethoxy)phenyl
2-hydroxy-2-propyl ketone, 2,2-diethoxyacetophenone,
4-benzoyl-4'-methyldiphenyl sulfide, ethyl
4-(dimethylamino)benzoate, mixtures of 2-isopropylthioxanthone and
4-isopropylthioxanthone, 2-(dimethylamino)ethyl benzoate,
d,I-camphorquinone, ethyl-d,I-camphorquinone, mixtures of
benzophenone and 4-methylbenzophenone, benzophenone,
4,4'-bis(dimethylamine)benzophenone, cyclopentadienyl)
(.eta..sup.6-isopropylphenyl)iron(II) hexafluorophosphate,
triphenylsulfonium hexafluorophosphate or mixtures of
triphenylsulfonium salts, and butanediol diacrylate, dipropylene
glycol diacrylate, hexanediol diacrylate,
4-(1,1-dimethylethyl)cyclohexyl acrylate, trimethylolpropane
triacrylate and tripropylene glycol diacrylate.
[0017] These photoinitiators C.1 are commercially available under
the brand names Lucirin.RTM., Irgacure.RTM. and Darocure.RTM..
Preference is given to using the initiators Lucirin.RTM. TPO,
Lucirin.RTM. TPO-L, Irgacure.RTM. Oxe 01, Irgacure.RTM. Oxe 02,
Irgacure.RTM. 1300, Irgacure.RTM. 184, Irgacure.RTM. 369,
Irgacure.RTM. 907 or Darocure.RTM. 1173, and particular preference
to using the initiators Lucirin.RTM. TPO, Lucirin.RTM. TPO-L,
Irgacure.RTM. Oxe 01, Irgacure.RTM. Oxe 02, Irgacure.RTM. 1300 or
Irgacure.RTM. 907.
[0018] The photoinitiators are used typically in a proportion of
about 0.1 to 5.0% by weight based on the total weight of the
inventive liquid-crystalline mixtures. Specifically when the
hardening is performed under inert gas atmosphere, it is possible
to use significantly smaller amounts of photoinitiators. In this
case, the photoinitiators are used in a proportion of about 0.1 to
1.0% by weight, preferably 0.2 to 0.6% by weight, based on the
total weight of the inventive liquid-crystalline mixtures.
[0019] The reactive diluents C.2 which are typically capable of
photopolymerization include, for example, mono-, bi- or
polyfunctional compounds having at least one olefinic double bond.
Examples thereof are vinyl esters of carboxylic acids, for example
of lauric acid, myristic acid, palmitic acid or stearic acid, or of
dicarboxylic acids, for example of succinic acid and adipic acid,
allyl or vinyl ethers or methacrylic or acrylic esters of
monofunctional alcohols, for example of lauryl alcohol, myristyl
alcohol, palmityl alcohol or stearyl alcohol, or diallyl or divinyl
ethers of bifunctional alcohols, for example of ethylene glycol and
of butane-1,4-diol.
[0020] Further useful examples are methacrylic or acrylic esters of
polyfunctional alcohols, especially of those which alongside the
hydroxyl groups comprise no further functional groups or, at most,
ether groups. Examples of such alcohols are, for example,
bifunctional alcohols such as ethylene glycol, propylene glycol,
and their more highly condensed representatives, for example
diethylene glycol, triethylene glycol, dipropylene glycol,
tripropylene glycol, etc., butanediol, pentanediol, hexanediol,
neopentyl glycol, alkoxylated phenolic compounds such as
ethoxylated or propoxylated bisphenols, cyclohexanedimethanol,
trifunctional and higher-functionality alcohols such as glycerol,
trimethylolpropane, butanetriol, trimethylolethane,
pentaerythritol, ditrimethylolpropane, dipentaerythritol, sorbitol,
mannitol and the corresponding alkoxylated, especially ethoxylated
and propoxylated, alcohols.
[0021] Further useful reactive diluents C.2 include polyester
(meth)acrylates, which are the (meth)acrylic esters of
polyesterols.
[0022] Useful polyesterols include, for example, those which can be
prepared by esterifying polycarboxylic acids, preferably
dicarboxylic acids, with polyols, preferably diols. The starting
materials for such hydroxyl-containing polyesters are known to
those skilled in the art. The dicarboxylic acids used may be
succinic acid, glutaric acid, adipic acid, sebacic acid, o-phthalic
acid, and their isomers and hydrogenation products, and also
esterifiable or transesterifiable derivatives of the acids
mentioned, for example anhydrides or dialkyl esters. Useful polyols
include the abovementioned alcohols, preferably ethylene glycol,
1,2- and 1,3-propylene glycol, 1,4-butanediol, 1,6-hexanediol,
neopentyl glycol, cyclohexanedimethanol and polyglycols of the
ethylene glycol and propylene glycol type.
[0023] Also useful as reactive diluents of group C.2 are
1,4-divinylbenzene, triallyl cyanurate, acrylic esters of
tricyclodecenyl alcohol of the following formula
##STR00007##
also known by the name dihydrodicyclopentadienyl acrylate, and the
allyl esters of acrylic acid, of methacrylic acid and of
cyanoacrylic acid.
[0024] When reactive diluents are used, the amount and properties
thereof have to be adjusted to the particular conditions in such a
way that, on the one hand, a satisfactory desired effect, for
example the desired reflected wavelength of the inventive
liquid-crystalline mixtures, is achieved, but, on the other hand,
the phase behavior of the liquid-crystalline mixture is not too
greatly impaired. For the preparation of low-crosslinking
(high-crosslinking) liquid-crystalline mixtures, it is possible,
for example, to use appropriate reactive diluents which have a
relatively low (high) number of reactive units per molecule.
[0025] The reactive diluents are typically used in a proportion of
about 0.5 to 20.0% by weight, based on the total weight of the
inventive liquid-crystalline mixtures.
[0026] Solvents C.3 include, for example, C.sub.1-C.sub.4-alcohols,
for example methanol, ethanol, n-propanol, isopropanol, butanol,
isobutanol, sec-butanol, tert-butanol, and the
C.sub.5-C.sub.12-alcohols n-pentanol, n-hexanol, n-heptanol,
n-octanol, n-nonanol, n-decanol, n-undecanol and n-dodecanol and
isomers thereof, glycols, for example 1,2-ethylene glycol, 1,2- or
1,3-propylene glycol, 1,2-, 2,3- or 1,4-butylene glycol, di- or
triethylene glycol or di- or tripropylene glycol, ethers, for
example open-chain ethers such as methyl tert-butyl ether,
1,2-ethylene glycol monomethyl or dimethyl ether, 1,2-ethylene
glycol monoethyl or diethyl ether, 3-methoxypropanol or
3-isopropoxypropanol, or cyclic ethers such as tetrahydrofuran or
dioxane, open-chain ketones, for example acetone, methyl ethyl
ketone, methyl isobutyl ketone or diacetone alcohol
(4-hydroxy-4-methyl-2-pentanone), cyclic ketones such as
cyclopentanone or cyclohexanone, C.sub.1-C.sub.5-alkyl esters, for
example methyl acetate, ethyl acetate, propyl acetate, butyl
acetate or amyl acetate,
C.sub.1-C.sub.4-alkoxy-C.sub.1-C.sub.4-alkyl esters such as
1-methoxyprop-2-yl acetate, carboxamides such as dimethylformamide
and dimethylacetamide, N-heterocycles such as N-methylpyrrolidone,
aliphatic or aromatic hydrocarbons, for example pentane, hexane,
heptane, octane, isooctane, petroleum ether, toluene, xylene,
ethylbenzene, tetralin, decalin, dimethylnaphthalene, white spirit,
Shellsol.RTM. or Solvesso.RTM.. As a matter of course, mixtures of
these solvents are also useful for use in the inventive
mixtures.
[0027] Particularly suitable diluents in the inventive
liquid-crystalline mixtures are linear or branched esters,
particularly acetic esters,
C.sub.1-C.sub.4-alkoxy-C.sub.1-C.sub.4-alkyl esters such as
1-methoxyprop-2-yl acetate, cyclic esters, carboxamides such as
dimethylformamide and dimethylacetamide, open-chain and cyclic
ethers, alcohols, lactones, open-chain and cyclic ketones such as
cyclopentanone and cyclohexanone, and aliphatic and aromatic
hydrocarbons such as toluene, xylene and cyclohexane.
[0028] The solvents are used typically in a proportion of about 50
to 95% by weight, preferably of about 65 to 80% by weight, based on
the total weight of the inventive liquid-crystalline mixtures.
According to the intended application, the proportion may, however,
be higher or lower than the limits specified.
[0029] The effects of the defoamers and deaerators C.4, lubricants
and leveling agents C.5, thermally curing or radiatively curing
auxiliaries C.6, substrate wetting aids C.7, wetting and dispersing
aids C.8, hydrophobizing agents C.9, adhesion promoters C.10 and
auxiliaries for improving scratch resistance C.11 listed under
component C usually cannot be strictly delimited from one another.
For instance, lubricants and leveling agents often additionally act
as defoamers and/or deaerators and/or as auxiliaries for improving
scratch resistance. Radiatively curing auxiliaries can in turn act
as lubricants and leveling agents and/or deaerators and/or also as
substrate wetting aids. In the individual case, some of these
auxiliaries may also perform the function of an adhesion promoter
C.11. In accordance with the above statements, a certain additive
may therefore be attributed to more than one of the groups C.4 to
C.11 described below.
[0030] The defoamers of group C.4 include silicon-free and
silicon-containing polymers. The silicon-containing polymers are,
for example, unmodified or modified polydialkylsiloxanes or
branched copolymers, comb copolymers or block copolymers composed
of polydialkylsiloxane and polyether units, the latter being
obtainable from ethylene oxide or propylene oxide.
[0031] The deaerators of group C.4 include, for example, organic
polymers, for instance polyethers and polyacrylates,
dialkylpolysiloxanes, especially dimethylpolysiloxanes, organically
modified polysiloxanes, for instance arylalkyl-modified
polysiloxanes, or else fluorosilicones. The action of defoamers is
based essentially on preventing foam formation or destroying foam
which has already formed. Deaerators act essentially by promoting
coalescence of finely distributed gas or air bubbles to larger
bubbles in the medium to be deaerated, for example the inventive
mixtures, and hence accelerate the escape of the gas (or of the
air). Since defoamers can often also be used as deaerators and vice
versa, these additives have been combined together under group
C.4.
[0032] Such auxiliaries are, for example, obtainable commercially
from Tego as TEGO.RTM. Foamex 800, TEGO.RTM. Foamex 805, TEGO.RTM.
Foamex 810, TEGO.RTM. Foamex 815, TEGO.RTM. Foamex 825, TEGO.RTM.
Foamex 835, TEGO.RTM. Foamex 840, TEGO.RTM. Foamex 842, TEGO.RTM.
Foamex 1435, TEGO.RTM. Foamex 1488, TEGO.RTM. Foamex 1495,
TEGO.RTM. Foamex 3062, TEGO.RTM. Foamex 7447, TEGO.RTM. Foamex
8020, Tego.RTM. Foamex N, TEGO.RTM. Foamex K 3, TEGO.RTM. Antifoam
2-18, TEGO.RTM. Antifoam 2-57, TEGO.RTM. Antifoam 2-80, TEGO.RTM.
Antifoam 2-82, TEGO.RTM. Antifoam 2-89, TEGO.RTM. Antifoam 2-92,
TEGO.RTM. Antifoam 14, TEGO.RTM. Antifoam 28, TEGO.RTM. Antifoam
81, TEGO.RTM. Antifoam D 90, TEGO.RTM. Antifoam 93, TEGO.RTM.
Antifoam 200, TEGO.RTM. Antifoam 201, TEGO.RTM. Antifoam 202,
TEGO.RTM. Antifoam 793, TEGO.RTM. Antifoam 1488, TEGO.RTM. Antifoam
3062, TEGOPREN.RTM. 5803, TEGOPREN.RTM. 5852, TEGOPREN.RTM. 5863,
TEGOPREN.RTM. 7008, TEGO.RTM. Antifoam 1-60, TEGO.RTM. Antifoam
1-62, TEGO.RTM. Antifoam 1-85, TEGO.RTM. Antifoam 2-67, TEGO.RTM.
Antifoam WM 20, TEGO.RTM. Antifoam 50, TEGO.RTM. Antifoam 105,
TEGO.RTM. Antifoam 730, TEGO.RTM. Antifoam MR 1015, TEGO.RTM.
Antifoam MR 1016, TEGO.RTM. Antifoam 1435, TEGO.RTM. Antifoam N,
TEGO.RTM. Antifoam KS 6, TEGO.RTM.Antifoam KS 10, TEGO.RTM.
Antifoam KS 53, TEGO.RTM. Antifoam KS 95, TEGO.RTM. Antifoam KS
100, TEGO.RTM. Antifoam KE 600, TEGO.RTM. Antifoam KS 911,
TEGO.RTM. Antifoam MR 1000, TEGO.RTM. Antifoam KS 1100, Tego.RTM.
Airex 900, Tego.RTM. Airex 910, Tego.RTM. Airex 931, Tego.RTM.
Airex 935, Tego.RTM. Airex 960, Tego.RTM. Airex 970, Tego.RTM.
Airex 980 and Tego.RTM. Airex 985, and from BYK as BYK.RTM.-011,
BYK.RTM.-019, BYK.RTM.-020, BYK.RTM.-021, BYK.RTM.-022,
BYK.RTM.-023, BYK.RTM.-024, BYK.RTM.-025, BYK.RTM.-027,
BYK.RTM.-031, BYK.RTM.-032, BYK.RTM.-033, BYK.RTM.-034,
BYK.RTM.-035, BYK.RTM.-036, BYK.RTM.-037, BYK.RTM.-045,
BYK.RTM.-051, BYK.RTM.-052, BYK.RTM.-053, BYK.RTM.-055,
BYK.RTM.-057, BYK.RTM.-065, BYK.RTM.-067, BYK.RTM.-070,
BYK.RTM.-080, BYK.RTM.-088, BYK.RTM.-141 and BYK.RTM.-A 530.
[0033] The auxiliaries of group C.4 are typically used in a
proportion of about 0.05 to 5.0% by weight, based on the total
weight of the inventive liquid-crystalline mixtures.
[0034] The group C.5 of the lubricants and leveling agents
typically includes, for example, silicon-free but also
silicon-containing polymers, for example polyacrylates or modified
low molecular weight polydialkylsiloxanes. The modification
consists in replacing some of the alkyl groups with a wide variety
of organic radicals. These organic radicals are, for example,
polyethers, polyesters or else long-chain alkyl radicals, the
former finding most frequent use.
[0035] The polyether radicals of the correspondingly modified
polysiloxanes are typically formed by means of ethylene oxide
and/or propylene oxide units. The higher the proportion of these
alkylene oxide units is in the modified polysiloxane, the more
hydrophilic is generally the resulting product.
[0036] Such auxiliaries are obtainable commercially, for example,
from Tego as TEGO.RTM. Glide 100, TEGO.RTM. Glide ZG 400, TEGO.RTM.
Glide 406, TEGO.RTM. Glide 410, TEGO.RTM.Glide 411, TEGO.RTM. Glide
415, TEGO.RTM. Glide 420, TEGO.RTM. Glide 435, TEGO.RTM. Glide 440,
TEGO.RTM. Glide 450, TEGO.RTM. Glide A 115, TEGO.RTM. Glide B 1484
(also usable as a defoamer and deaerator), TEGO.RTM. Flow ATF,
TEGO.RTM. Flow ATF2, TEGO.RTM. Flow 300, TEGO.RTM. Flow 460,
TEGO.RTM. Flow 425 and TEGO.RTM. Flow ZFS 460. The
radiation-curable lubricants and leveling agents used, which
additionally also serve to improve scratch resistance, can be the
products TEGO.RTM. Rad 2100, TEGO.RTM. Rad 2200, TEGO.RTM. Rad
2300, TEGO.RTM. Rad 2500, TEGO.RTM. Rad 2600, TEGO.RTM. Rad 2700
and TEGO.RTM. Twin 4000, likewise obtainable from Tego. Examples of
such auxiliaries obtainable from BYK are BYK.RTM.-300,
BYK.RTM.-306, BYK.RTM.-307, BYK.RTM.-310, BYK.RTM.-320,
BYK.RTM.-322, BYK.RTM.-331, BYK.RTM.-333, BYK.RTM.-337,
BYK.RTM.-341, Byk.RTM. 354, Byk.RTM. 361 N, BYK.RTM.-378 and
BYK.RTM.-388.
[0037] The auxiliaries of group C.5 are typically used in a
proportion of about 0.01 to 5.0% by weight, based on the total
weight of the inventive liquid-crystalline mixtures.
[0038] Group C.6 includes, as radiatively curing auxiliaries, in
particular polysiloxanes with terminal double bonds which are, for
example, part of an acrylate group. Such auxiliaries can be made to
crosslink by actinic or, for example, electron beam radiation.
[0039] These auxiliaries generally combine several properties in
one. In the uncrosslinked state, they can act as defoamers,
deaerators, lubricants and leveling agents and/or substrate wetting
aids; in the crosslinked state, they increase in particular the
scratch resistance, for example of coatings or films which can be
produced with the inventive mixtures. The improvement in the gloss
performance of, for example, coatings or films can essentially be
regarded as the effect of the action of these auxiliaries as
defoamers, deaerators and/or lubricants and leveling agents (in the
uncrosslinked state). Radiation-curing auxiliaries which can be
used are, for example, the products TEGO.RTM. Rad 2100, TEGO.RTM.
Rad 2200, TEGO.RTM. Rad 2500, TEGO.RTM. Rad 2600 and TEGO.RTM. Rad
2700 obtainable from Tego, and the product BYK.RTM.-371 obtainable
from BYK.
[0040] The auxiliaries of group C.6 are typically used in a
proportion of about 0.01 to 5.0% by weight, based on the total
weight of the inventive liquid-crystalline mixtures.
[0041] The auxiliaries of group C.7 of the substrate wetting aids
serve in particular to increase the wettability of the substrates
which are to be printed or coated with the inventive
liquid-crystalline mixtures. There is generally an associated
improvement in the lubricating and leveling performance of
inventive liquid-crystalline mixtures, and this has an effect on
the appearance of the finished (for example crosslinked) print or
of the finished (for example crosslinked) layer. A wide variety of
such auxiliaries are commercially available, for example, from Tego
as TEGO.RTM. Wet KL 245, TEGO.RTM. Wet 250, TEGO.RTM. Wet 260 and
TEGO.RTM. Wet ZFS 453, and from BYK as BYK.RTM.-306, BYK.RTM.-307,
BYK.RTM.-310, BYK.RTM.-333, BYK.RTM.-344, BYK.RTM.-345,
BYK.RTM.-346 and Byk.RTM.-348.
[0042] Also very suitable are the products of the Zonyl.RTM. brand
from Dupont, such as Zonyl.RTM. FSA and Zonyl.RTM. FSG. These are
fluorinated surfactants/wetting agents.
[0043] The auxiliaries of group C.7 are typically used in a
proportion of about 0.01 to 5.0% by weight, based on the total
weight of the inventive liquid-crystalline mixtures.
[0044] The auxiliaries of group C.8 of the wetting and dispersing
aids serve in particular to prevent the flotation and also the
settling of pigments, and are therefore useful, if necessary, in
pigmented inventive liquid-crystalline mixtures in particular.
[0045] These auxiliaries stabilize pigment dispersions essentially
by electrostatic repulsion and/or steric hindrance of the additized
pigment particles, the interaction of the auxiliary with the
surrounding medium (for example binder) playing a major role in the
latter case. Since the use of such wetting and dispersing aids is
common practice, for example, in the technical field of printing
inks and paints, the selection of such a suitable auxiliary in any
given case generally presents no difficulties to the person skilled
in the art.
[0046] Such wetting and dispersing aids are supplied commercially,
for example, by Tego as TEGO.RTM. Dispers 610, TEGO.RTM. Dispers
610 S, TEGO.RTM. Dispers 630, TEGO.RTM. Dispers 700, TEGO.RTM.
Dispers 705, TEGO.RTM. Dispers 710, TEGO.RTM. Dispers 720 W,
TEGO.RTM. Dispers 725 W, TEGO.RTM. Dispers 730 W, TEGO.RTM. Dispers
735 W and TEGO.RTM. Dispers 740 W, and by BYK as Disperbyk.RTM.,
Disperbyk.RTM.-107, Disperbyk.RTM.-108, Disperbyk.RTM.-110,
Disperbyk.RTM.-111, Disperbyk.RTM.-115, Disperbyk.RTM.-130,
Disperbyk.RTM.-160, Disperbyk.RTM.-161, Disperbyk.RTM.-162,
Disperbyk.RTM.-163, Disperbyk.RTM.-164, Disperbyk.RTM.-165,
Disperbyk.RTM.-166, Disperbyk.RTM.-167, Disperbyk.RTM.-170,
Disperbyk.RTM.-174, Disperbyk.RTM.-180, Disperbyk.RTM.-181,
Disperbyk.RTM.-182, Disperbyk.RTM.-183, Disperbyk.RTM.-184,
Disperbyk.RTM.-185, Disperbyk.RTM.-190, Anti-Terra.RTM.-U,
Anti-Terra.RTM.-U 80, Anti-Terra.RTM.-P, Anti-Terra.RTM.-203,
Anti-Terra.RTM.-204, Anti-Terra.RTM.5 206, BYK.RTM.-151,
BYK.RTM.-154, BYK.RTM.-155, BYK.RTM.-P 104 S, BYK.RTM.-P 105,
Lactimon.RTM., Lactimon.RTM.-WS and Bykumen.RTM.. The
abovementioned Zonyl.RTM. brands, such as Zonyl.RTM. FSA and
Zonyl.RTM. FSG, from DuPont are also useful here.
[0047] The dosage of the auxiliaries of group C.8 depends mainly
upon the surface area to be covered on the pigments and upon the
mean molar mass of the auxiliary.
[0048] For inorganic pigments and low molecular weight auxiliaries,
a content of the latter of about 0.5 to 2.0% by weight based on the
total weight of pigment and auxiliary is typically assumed. In the
case of high molecular weight auxiliaries, the content is increased
to about 1.0 to 30% by weight.
[0049] In the case of organic pigments and low molecular weight
auxiliaries, the content of the latter is about 1.0 to 5.0% by
weight based on the total weight of pigment and auxiliary. In the
case of high molecular weight auxiliaries, this content may be in
the range about 10.0 to 90% by weight. In every case, therefore,
preliminary experiments are recommended, but these are easily
accomplished by the person skilled in the art.
[0050] The hydrophobizing agents of group C.9 can be used with a
view, for example, to providing prints or coatings with
water-repellent properties by using inventive liquid-crystalline
mixtures. This means that swelling resulting from water absorption
and resultant change, for example, in the optical properties of
such prints or coatings is no longer possible or at least greatly
suppressed. In addition, when the mixtures are used, for example,
as a printing ink in offset printing, their absorption of water can
be prevented or at least greatly inhibited.
[0051] Such hydrophobizing agents are commercially available, for
example, from Tego as Tego.RTM. Phobe WF, Tego.RTM. Phobe 1000,
Tego.RTM. Phobe 1000 S, Tego.RTM. Phobe 1010, Tego.RTM. Phobe 1030,
Tego.RTM. Phobe 1040, Tego.RTM. Phobe 1050, Tego.RTM. Phobe 1200,
Tego.RTM. Phobe 1300, Tego.RTM. Phobe 1310 and Tego.RTM. Phobe
1400.
[0052] The auxiliaries of group C.9 are used typically in a
proportion of about 0.05 to 5.0% by weight, based on the total
weight of the inventive liquid-crystalline mixtures.
[0053] Adhesion promoters of group C.10 serve to improve the
adhesion between two interfaces in contact. It immediately becomes
evident from this that essentially only the proportion of the
adhesion promoter which is present in one interface, the other
interface or in both interfaces is effective. When the intention is
to apply, for example, liquid or pasty printing inks, coatings or
paints to a solid substrate, this generally means that either the
adhesion promoter has to be added directly to the latter or the
substrate has to be subjected to a pretreatment with the adhesion
promoters (also known as priming), i.e. that changed chemical
and/or physical surface properties are imparted to this
substrate.
[0054] To the extent that the substrate has been primed beforehand
with a undercoat, this means that the interfaces in contact are now
that of the undercoat on the one hand and that of the inventive
liquid-crystalline mixtures on the other hand. Thus, in this case,
not only the adhesion properties between substrate and undercoat,
but also between undercoat and the inventive liquid-crystalline
mixtures, are of significance for the adhesion of the entire
combination on the substrate. It is also possible for the substrate
wetting aids already detailed under group C.7 to be addressed as
adhesion promoters in the wider sense, but these generally do not
have the same capacity for adhesion promotion.
[0055] In view of the wide variety of physical and chemical
properties of substrates and of inventive liquid-crystalline
mixtures envisaged, for example, for the printing or coating
thereof, the multitude of adhesion promoter systems is not
surprising. Adhesion promoters based on silanes are, for example,
3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane,
3-aminopropylmethyldiethoxysilane,
N-aminoethyl-3-aminopropyltrimethoxysilane,
N-aminoethyl-3-aminopropylmethyldimethoxysilane,
N-methyl-3-aminopropyltrimethoxysilane,
3-ureidopropyltriethoxysilane,
3-methacryloyloxypropyltrimethoxysilane,
3-glycidyloxypropyltrimethoxysilane,
3-mercaptopropyltrimethoxysilane, 3-chloropropyltrimethoxysilane or
vinyltrimethoxysilane. These and further silanes are obtainable,
for example, under the brand name DYNASILAN.RTM. from Huls.
[0056] Adhesion promoters based on titanates/zirconates and on
titanium/zirconium bisacetylacetonates correspond, for example, to
the following formulae
##STR00008##
in which M is titanium or zirconium, and R, R.sup.1 and R.sup.2 are
each C.sub.1-C.sub.4-alkyl, for example isopropyl or n-butyl.
Examples of such compounds are, for instance, tetraisopropyl
titanate, tetra-n-butyl titanate, titanium bis(acetylacetonate)
diisopropoxide, titanium bis(acetylacetonate) dibutoxide, titanium
bis(acetylacetonate) monobutoxide monoisopropoxide or titanium
bis(acetylacetonate) monoethoxide monoisopropoxide.
[0057] Further titanium and zirconium compounds usable as adhesion
promoters are n-butyl polytitanate, isopropyl
triisostearoyltitanate, isopropyl
tris(N-ethylaminoethylamino)-titanate and zirconium
bis(diethylcitrate) diisopropoxide. These and further titanium and
zirconium compounds are obtainable, for example, under the brand
names TYZOR.RTM. (from DuPont), Ken-React.RTM. (from Kenrich
Petrochemicals Inc.) and Tilcom.RTM. (from Tioxide Chemicals).
Adhesion promoters used may also be zirconium aluminates, as
obtainable, for example under the brand name Manchem.RTM. (from
Rhone Poulenc). Further examples of useful adhesion-promoting
additives in printing inks or paints are chlorinated polyolefins
(obtainable, for example, from Eastman Chemical and Toyo Kasei),
polyesters (obtainable, for example, from Huls AG, BASF SE, Gebr.
Borchers AG, Pluess-Staufer AG, Hoechst AG and Worlee), compounds
based on sucrose, for example sucrose benzoate or sucrose
acetoisobutyrate (the latter obtainable, for example, from Eastman
Chemical), phosphoric esters (obtainable, for example, from The
Lubrizol Company and Hoechst AG) and polyethyleneimines
(obtainable, for example, from BASF SE), and examples of useful
adhesion-promoting additives in printing inks for flexographic
printing, film printing and packaging printing are rosin esters
(obtainable, for example, from Robert Kraemer GmbH).
[0058] Typically, the substrate to be printed or to be coated will
be pretreated appropriately, i.e. such additives will be used as
primers. Appropriate technical information for this purpose can
generally be learnt from the manufacturers of such additives, or
the person skilled in the art can obtain this information in a
simple manner by appropriate preliminary experiments.
[0059] If these additives, however, are to be added as auxiliaries
of group C.10 to the inventive liquid-crystalline mixtures, the
content thereof is typically about 0.05 to 5.0% by weight based on
the total weight of the inventive liquid-crystalline mixtures.
These concentration data serve merely as an indication, since the
amount and identity of the additive are determined in any
individual case by the nature of the substrate and of the
printing/coating composition. Typically, appropriate technical
information here is available from the manufacturers of such
additives, or can be determined by the person skilled in the art by
appropriate preliminary experiments in a simple manner.
[0060] The group C.11 of the auxiliaries for improving scratch
resistance includes, for example, the products TEGO.RTM. Rad 2100,
TEGO.RTM. Rad 2200, TEGO.RTM. Rad 2500, TEGO.RTM. Rad 2600 and
TEGO.RTM. Rad 2700 which are obtainable from Tego and have already
been mentioned above.
[0061] These additives are typically used in a proportion of about
0.1 to 5.0% by weight, based on the total weight of the inventive
liquid-crystalline mixtures.
[0062] Preferred chiral dopants C.12 correspond to the general
formulae (P--Y--).sub.pX, (P--Y-A-Y--).sub.PX and
(P--Y-A-Y-M-Y--).sub.p--X, in which the variables P represent
reactive or unreactive radicals, Y represents linking units, for
example single chemical bonds, oxygen atoms, CO, COO or O--COO, and
A represents spacers, M denotes mesogenic groups, p represents
values of 1, 2, 3, 4, 5 or 6 and X represents appropriate p-valent
chiral radicals, where the p moieties bonded to the chiral X
radical may be the same or different.
[0063] Possible X radicals are, for example, shown on pages 5 to 9
of the document WO 95/16007 A1, and particular mention should be
made of the divalent radicals
##STR00009##
[0064] Further chiral dopants which comprise the chiral X radicals
mentioned or other suitable chiral X radicals are specified, for
example, in the documents EP 0 747 382 A1, EP 0 750 029 A1, EP 1
136 478 A1 and DE 198 43 724 A1.
[0065] The present invention further provides oligomers or polymers
which are obtainable by oligomerizing or polymerizing inventive
liquid-crystalline mixtures. These inventive oligomers or polymers
may especially also be present in the form of films, i.e.
self-supporting layers of uniform thickness. These films may be
present on substrates, the properties of which are such that
suitable measures enable easy detachment and permanent transfer to
other substrates. Such films are usable, for example, in the film
coating sector and in lamination processes.
[0066] Furthermore, such films, whose properties have been adapted
to the particular end use, can be used in a wide variety of
different fields. For example, they may find use in devices for
displaying visual information. Such devices are, for instance,
video or overhead projectors, electrophoretic display devices,
traffic displays, LCDs for use in computer monitors, or in
televisions, or in visual display units in printers or kitchen
appliances, and also advertising panels, illumination systems and
information panels, and additionally mobile visual display units,
for example visual display units in cellphones, laptops, digital
cameras, vehicles and destination displays on buses and trains.
They may be present in these devices in a wide variety of
functions, for example as color filters or films for the generation
of wavelength-selective or broadband-polarized light.
[0067] The present invention further provides a process for
printing or coating substrates, which comprises applying inventive
liquid-crystalline mixtures to the substrate and then polymerizing
them.
[0068] With regard to the procedure for printing or coating
substrates with liquid-crystalline materials, reference is made
mutatis mutandis to the document WO 96/02597 A2. Furthermore, a
polymerized layer which has been produced with the aid of the
process according to the invention and partly or fully covers the
original substrate surface should also be considered as a substrate
in the context of the application, and so the production of
multiply printed and/or coated substrates is also encompassed by
the invention.
[0069] It should further be noted here that "printing" is typically
understood to mean the incomplete coverage of the substrate
surface, and "coating" to mean the full coverage of the substrate
surface.
[0070] Useful substrates in addition to paper and card products,
for example for carrier bags, magazines, brochures, gift packaging
and packaging materials for consumer goods, consumable goods and
luxury goods, are additionally also films, for instance for
decorative and nondecorative packaging purposes, and also textiles
of any type and leather. In addition, useful substrates are also
those materials used to produce banknotes, securities, entrance
tickets, and the like.
[0071] Further substrates are also goods for (entertainment)
electronics, for example music cassettes (MCs), SVHS and VHS
cassettes, minidisks (MDs), compact disks (CDs), digital versatile
disks (DVDs), Blu-ray disks (BDs) and the corresponding
reproduction and/or recording units, televisions, radios,
telephones/cellphones, computers, etc, and goods from the leisure,
sports, domestic and games sector, for instance bicycles,
children's vehicles, skis, snowboards and surfboards, inline
skates, roller skates and ice skates and also domestic appliances.
In addition, such substrates should also be understood to mean, for
example, writing utensils and spectacle frames.
[0072] Further substrates are also a very wide variety of films
which find use in optical or electrooptical components or in their
production. Such films consist, for example, of polyvinyl alcohol
(PVA), triacetylcellulose (TAC), polyimide (PI), polyvinyl
cinnamate (PVC) or polyolefins, for instance polynorbornene, and
may, for example, be (broadband) polarizers, light-guiding elements
for background illumination in LCDs (known as "light guides"),
films for the distribution of light (known as "BEFs", i.e.
"brightness enhancement films") and films for the generation of
polarized light in LCDs (known as "DBEFs", i.e. "dual brightness
enhancement films"). Further substrates in this context may also be
certain structural modules of LCDs, for instance glass or polymer
sheets which, if appropriate, also possess a transparent conductive
coating, for example of indium tin oxide (ITO).
[0073] Light guides or BEFs can, for example, be coated directly
with inventive nematic (i.e. no chiral compounds C.12 are present)
or chiral nematic (i.e. chiral compounds C.12 are present) mixtures
and the latter can subsequently be polymerized. The coating
operation may be repeated any number of times with inventive
liquid-crystalline mixtures of the same or different composition in
order to obtain corresponding optical components, for instance
retardation films, (broadband) polarizers and optical filters. This
allows production of a correspondingly more compact structure of
the optical components in LCDs.
[0074] In addition, the process according to the invention can be
used to apply a suitable nematic layer as a retardation film to a
(broadband) polarizer which affords circular-polarized light. This
allows circular-polarized light to be converted to linear-polarized
light. In this case, the (broadband) polarizer may likewise have
been produced from inventive mixtures, optionally using the process
according to the invention.
[0075] Further substrates which are useful especially for the
production of inventive thermal insulation layers or thermally
insulating films and laminates are the backing films detailed in
international PCT application PCT/EP2009/057533.
[0076] As materials for the backing films, explicit mention should
be made here of polyethylene terephthalate, polyethylene
naphthalate, polyvinyl butyral, polyvinyl chloride, flexible
polyvinyl chloride, polymethyl methacrylate, poly(ethylene-co-vinyl
acetate), polycarbonate, cellulose triacetate, polyether sulfone,
polyester, polyamide, polyolefins and acrylic resins. Among these,
polyethylene terephthalate, polyvinyl butyral, polyvinyl chloride,
flexible polyvinyl chloride and polymethyl methacrylate are
preferred.
[0077] The backing film is preferably biaxially oriented.
[0078] Further substrates are, however, also surfaces encountered
in the construction sector, such as building walls or else window
panes. In the latter case, a functional effect may also be desired
in addition to a decorative effect. For instance, it is possible to
produce multiple layers on the window material, the individual
layers of which possess different physicochemical properties. When,
for instance, addition of one enantiomer of a chiral compound C.12
and of the corresponding optical antipode is used to apply
individual layers of the polymerized liquid-crystalline mixtures
with opposite rotation, or addition of different concentrations of
chiral compound C.12 is used to apply individual layers of the
polymerized liquid-crystalline mixtures having the same sense of
rotation but each with different pitch and hence different
reflection properties, it is possible in a controlled manner to
reflect particular wavelengths or wavelength ranges of the spectrum
of light. This makes possible, for example IR- or UV-reflective
window coating.
[0079] Accordingly, the present invention further provides for the
use of inventive liquid-crystalline mixtures which comprise as
component C at least one chiral dopant (component C.12) for
production of thermal insulation layers, comprising one or more
cholesteric layers which reflect at least 40%, especially at least
45%, of the incident radiation in the wavelength range, preferably
in the wavelength range from 750 nm to 2000 nm.
[0080] The present invention further provides for the use of
inventive liquid-crystalline mixtures which comprise as component C
at least one chiral dopant (component C.12) for production of
thermal insulation layers, comprising one or more cholesteric
layers which have a transmission of at least 80%, especially at
least 90%, of the incident radiation in the wavelength range from
390 nm to 750 nm.
[0081] More particularly claimed within the scope of the present
invention are thermal insulation layers which comprise one or more
cholesteric layers which reflect at least 40%, especially at least
45%, of the incident radiation in the infrared wavelength range,
preferably in the wavelength range from 750 nm to 2000 nm, which
are obtainable using inventive liquid-crystalline mixtures
comprising as component C at least one chiral dopant (component
C.12).
[0082] Additionally claimed within the scope of the present
invention are also thermal insulation layers which comprise one or
more cholesteric layers which have a transmission of at least 80%,
especially at least 90%, of the incident radiation in the
wavelength range from 390 nm to 750 nm, which are obtainable using
inventive liquid-crystalline mixtures comprising as component C at
least one chiral dopant (component C.12).
[0083] The inventive thermal insulation layers in this context may
be self-supporting layers or films which consist essentially only
of inventive chiral nematic (i.e. chiral compounds C.12 are
present) polymerized mixtures, or else laminates which comprise the
backing film(s) already mentioned above as an integral
constituent.
[0084] The backing film may additionally be coated on one or both
sides with the inventive chiral nematic (i.e. chiral compounds C.12
are present) and polymerized mixtures.
[0085] In the case of single-sided coating, the backing film may
remain in the thermal insulation layer and hence become an integral
constituent thereof, or the backing film merely assumes the
function of a backing during the production of the thermal
insulation layer and is subsequently removed to leave a
self-supporting thermally insulating film or a self-supporting
thermally insulating layer.
[0086] In the case of double-sided coating, the backing film of
course remains in the thermal insulation layer and becomes an
integral constituent thereof.
[0087] With regard to this aspect of the inventive
liquid-crystalline mixtures, especially in relation to thermal
insulation layers, reference is made not only to the prior PCT
application PCT/EP2009/057533 but also mutatis mutandis to the
document WO 99/19267 A1.
[0088] The present invention further provides for the use of the
inventive liquid-crystalline mixtures or of the inventive oligomers
or polymers for production of optical or electrooptical components.
Examples thereof include LCDs and components thereof, for example
(broadband) polarizers, optical filters, retardation films and
BEFs.
[0089] With regard to the production of such components based on
polymerizable liquid-crystalline materials, reference is made
mutatis mutandis, for instance, to the document WO 00/37585 A1.
[0090] With regard to the use of inventive chiral nematic mixtures
for production of (broadband) polarizers, reference is made mutatis
mutandis, for example, to the documents U.S. Pat. No. 6,421,107,
U.S. Pat. No. 6,417,902, U.S. Pat. No. 6,061,108, U.S. Pat. No.
6,099,758, U.S. Pat. No. 6,016,177, U.S. Pat. No. 5,948,831, U.S.
Pat. No. 5,793,456, U.S. Pat. No. 5,691,789 and U.S. Pat. No.
5,506,704.
[0091] With regard to the use of inventive liquid-crystalline
mixtures for production of DBEFs, reference is made mutatis
mutandis, for example, to the documents U.S. Pat. No. 4,525,413,
U.S. Pat. No. 5,828,488 and U.S. Pat. No. 5,965,247.
[0092] The latter two documents describe laminates of polymer
layers whose optical properties are such that one layer S.sup.1
exhibits either isotropic or anisotropic optical behavior, but the
adjacent layer S.sup.2 exhibits anisotropic optical behavior
differing from S.sup.1. The value of the refractive index
n.sub.1.sup.1 in one planar direction of S.sup.1 corresponds
substantially to the refractive index n.sub.1.sup.2 in the same
planar direction of S.sup.2, but the refractive indices
n.sub.2.sup.1 and n.sub.2.sup.2 for S.sup.1 and S.sup.2 in the
respective planar direction at right angles thereto differ. Light
rays incident on these laminates are therefore, depending on their
direction of polarization, either transmitted (when n.sub.1.sup.1
and n.sub.1.sup.2 are substantially equal) or reflected (when
n.sub.2.sup.1 and n.sub.2.sup.2 are different from one another).
The anisotropic layers S.sup.2 may therefore, in alternation with
polymer layers with suitable isotropic or anisotropic refractive
index, consist of corresponding polymers or oligomers obtained by
polymerization of inventive nematic mixtures. Examples of useful
polymer layers S.sup.1 are also adhesives which bond the
anisotropic layers S.sup.2 to one another, or polymer films with
suitable glass transition temperatures, which form the desired
laminate together with the layers S.sup.2 in the case of suitable
thermal treatment. In addition, a polymer layer S.sup.1 can be
coated with an inventive nematic mixture, a further polymer layer
S.sup.1 can be applied and then the mixture between the two polymer
layers S.sup.1 can be polymerized. Irrespective of the procedure
selected for production of such laminates, sufficiently good
adhesion of the layers S.sup.1 and S.sup.2 to one another of course
has to be ensured.
[0093] The inventive liquid-crystalline mixtures can also be used
as a disperse liquid-crystalline phase in polymer-dispersed liquid
crystals (PDLCs). Such PDLCs may in principle either have an
isotropic polymer matrix and both a macroscopically isotropic and
an anisotropic disperse liquid-crystalline phase, or an anisotropic
polymer matrix and both a macroscopically isotropic and an
anisotropic disperse liquid-crystalline phase, in which case the
macroscopically isotropic phase results from the random
distribution of microscopically anisotropic domains.
[0094] In general, such PDLCs are produced proceeding from a
(generally optically anisotropic) polymer film in which the
liquid-crystalline phase is present homogeneously dispersed in the
form of ultrafine inclusions, typically in the micrometer or
submicrometer size range. Stretching of the polymer film imposes
anisotropic optical behavior both on the polymer matrix and on the
disperse phase. When inventive liquid-crystalline mixtures are
used, the anisotropic state of the disperse phase can be frozen by
polymerization and hence, for example, distinctly better thermal
(cycling) stability can be achieved. The polymer matrix used here
is usually polyvinyl alcohol.
[0095] In addition, inventive chiral nematic mixtures--they
comprise at least one chiral dopant C.12--may, for example, also be
used to produce optical components, as described in documents U.S.
Pat. No. 5,235,443 and U.S. Pat. No. 5,050,966.
[0096] The inventive liquid-crystalline mixtures may additionally
also find use as a liquid-crystalline colorant or for production of
liquid-crystalline colorants. Use as colorants is possible when the
mixtures per se are colored. This color may be based on
interference effects of a chiral nematic phase present and/or on
absorption effects of dyes and/or pigments present. In addition,
the mixtures--irrespective of whether they are colored or not--may
also serve for production of colorants. With regard to the
production of liquid-crystalline colorants and the use thereof for
printing or coating substrates, reference is made mutatis mutandis
to the document WO 96/02597 A2.
[0097] The inventive liquid-crystalline mixtures may additionally
find use in the production of dispersions and emulsions, which are
preferably water-based. For production of such dispersions and
emulsions using liquid-crystalline materials, reference is made
here to WO documents 96/02597 A2 and 98/47979 A1. These dispersions
and emulsions can likewise be used for printing and coating of
substrates as have already been described above by way of
example.
[0098] In addition, the inventive mixtures may also find use in the
production of pigments. The production of such pigments is known
and is described in detail, for example, in document WO 99/11733
A1. Moreover, it is also possible to produce pigments preadjusted
in shape and size using printing techniques or with the aid of
networks whose interstices contain the liquid-crystalline mixtures.
The subsequent polymerization of the liquid-crystalline mixtures is
followed here by removal or leaching from the substrate or out of
the network. These procedures are described in detail in WO
documents 96/02597 A1, 97/27251 A1, 97/27252 A1, and the document
EP 0 931 110 A1.
[0099] These pigments may have a single layer or a multilayer
structure. The latter pigments are typically producible only when
coating processes are employed in which a plurality of successive
layers are superposed and finally subjected to mechanical
comminution.
[0100] The examples which follow are intended to illustrate the
invention, but without restricting it.
EXAMPLE
I. Preparation of Inventive Liquid-Crystalline Mixtures and of
Comparative Mixtures
[0101] On the basis of the nematic compounds
##STR00010##
and the chiral dopant
##STR00011##
mixtures A to E were prepared. The relative proportions of LC 1 and
LC 2 in % by weight and mol % are listed in tables 1a and 1b
respectively, and the absolute amounts in table 2.
TABLE-US-00001 TABLE 1a % by weight based on the total weight of LC
1 and LC 2 Mixture A Mixture B Mixture C Mixture D Mixture E
(compar- (compar- (inven- (compar- (compar- ative) ative) tive)
ative) ative) LC 1 0.0 100.0 75.0 50.0 25.0 LC 2 100.0 0.0 25.0
50.0 75.0
TABLE-US-00002 TABLE 1b mol % based on the total weight of LC 1 and
LC 2 Mixture A Mixture B Mixture C Mixture D Mixture E (compar-
(compar- (inven- (compar- (compar- ative) ative) tive) ative)
ative) LC 1 0.0 100.0 71.4 45.4 21.7 LC 2 100.0 0.0 28.6 54.6
78.3
TABLE-US-00003 TABLE 2 Mix- Mix- Mix- Mix- Mix- ture A ture B ture
C ture D ture E (compar- (compar- (inven- (compar- (compar- ative)
ative) tive) ative) ative) LC 1 0.000 g 31.334 g 23.500 g 15.667 g
7.833 g (compo- nent A) LC 2 31.334 g 0.000 g 7.833 g 15.667 g
23.500 g (compo- nent B) DS 1.650 g 1.650 g 1.650 g 1.650 g 1.650 g
(compo- nent C.12) Total weight 32.984 g 32.984 g 32.984 g 32.984 g
32.984 g of LC 1, LC 2 and DS Irgacure 1.649 g 1.649 g 1.649 g
1.649 g 1.649 g 907 (compo- nent C.1) Cyclo- 67.017 g 67.017 g
67.017 g 67.017 g 67.017 g pentanone (compo- nent C.3) Byk 1.649 g
1.649 g 1.649 g 1.649 g 1.649 g 361 N (compo- nent C.5)
[0102] The sums of the proportions of LC 1 and LC 2 on the one hand
and DS on the other hand, in all mixtures A to E, were 95% by
weight and 5% by weight respectively, based on the total weight of
LC 1, LC 2 and DS.
[0103] The mixtures A to E were prepared by stirring the components
at 50.degree. C. by means of a magnetic stirrer for 5 minutes and
then filtering (Whatman Puradisc 25TF, 1 .mu.m membrane
filter).
[0104] Subsequently, 2-2.5 ml of each mixture were applied to the
polymer substrate (PET Lumirror 4001, film thickness 50 .mu.m,
rubbed five times with velvet from Torray over the whole area for
better orientation of the mixtures) and drawn down to a film with a
30 .mu.m spiral bar coater. After evaporating off the solvent in a
closed fumehood (no ventilation) at 120.degree. C. for two minutes,
polymerization was effected under UV light (UV-AB with quartz
filter) for two minutes. This gave a layer thickness of approx.
4.5-5 .mu.m.
[0105] The films obtained were assessed qualitatively under an
optical microscope with a magnification of 100:1. Comparisons were
made against images of films of different quality (FIGS. 1 to 6);
the marks given ranged from 1 (best; FIG. 1) to 6 (worst; FIG.
6).
[0106] Table 3 lists the results for the polymer films obtained
from mixtures A to E.
TABLE-US-00004 TABLE 3 Film Layer Mixture quality (mark) thickness
A 4 4.7 .mu.m (comparative) B 5 4.8 .mu.m (comparative) C 1 4.9
.mu.m (inventive) D 2.5 5.0 .mu.m (comparative) E 4.5 4.9 .mu.m
(comparative)
[0107] The birefringence and width of the spectral reflection of
the polymer films changed in a substantially linear manner between
the values for 100% LC 1 (0% LC 2) and 100% LC 2 (0% LC 1).
II. Change in the Components of Mixtures A to E:
[0108] Analogous results were obtained when the solvent was changed
(component C.3), the photoinitiator was changed (component C.1) and
the amount of leveling aid added was changed (component C.5).
Solvent: 80:20 cyclohexanone/ethyl acetate (instead of
cyclopentanone) Photoinitiator: Irgacure OXE01 (instead of Irgacure
907) Amount of leveling aid (Byk 361 N): 0.825 g (instead of 1.649
g)
III. Change of Substrate and Application Method
[0109] Analogous results were obtained when the substrate and the
application method for mixtures A to E were changed.
Substrate: polyimide-coated glass (instead of Lumirror 4001)
Application method: spincoating (instead of spiral coating bar)
[0110] It should be mentioned that of course not every substrate is
suitable. To the extent that, however, orientation of the inventive
liquid-crystalline mixtures on the substrate can be achieved or the
latter is wetted by the inventive liquid-crystalline mixtures, a
distinct improvement in orientation and in the quality of the films
obtained is observed.
* * * * *