Liquid-crystalline mixtures
The present application relates to mixtures which have liquid-crystalline properties. The application furthermore relates to the use of the mixtures in devices which regulate the transmission of light through an area element.
1. A switchable window comprising:
a layer which comprises a mixture comprising one or more compounds of formula (1) or a formula (2),
where:
A 11 , A 12 , A 21 , A 22 , A 23 , A 24 are from
Z 11 , Z 21 , Z 22 , Z 23 are a single bond, —(C═O)—O, —O—(C═O)—, —CF 2 —O—, —O—CF 2 —, —O—CH 2 —, —CH 2 —O— or —CH 2 —CH 2 —;
R 11 , R 12 , R 21 , R 22 are on each occurrence, identically or differently, H, F, Cl, CN, NCS, alkyl groups having 1 to 10 C atoms, alkoxy groups having 1 to 10 C atoms, thioalkoxy groups having 1 to 10 C atoms, alkenyl groups having 2 to 10 C atoms and alkenyloxy groups having 2 to 10 C atoms, where one or more H atoms in the alkyl, alkoxy, thioalkoxy, alkenyl a or alkenyloxy groups may be replaced by F, Cl or CN;
T is —CN, F, —N 3 , —NCS, NO 2 , —C≡C—R 3 , alkyl groups having 1 to 10 C atoms or alkoxy groups having 1 to 10 C atoms, where one or more H atoms in the alkyl and alkoxy groups may be replaced by F, Cl or CN;
R 3 is H, CN, alkyl groups having 1 to 10 C atoms, where one or more C atoms in the alkyl groups may be replaced by F, Cl or CN, or —C≡C—R 4 ;
R 4 is H, CN, or alkyl groups having 1 to 10 C atoms, where one or more C atoms in the alkyl groups may be replaced by F, Cl or CN;
i is on each occurrence, identically or differently, 0 or 1, where the sum of the indices i in a formula is at least equal to 1;
k is on each occurrence, identically or differently, 0 or 1, where the sum of the indices k in a formula is at least equal to 1;
p is equal to 0 or 1;
and one or more compounds of the formula (3)
wherein
A31 is on each occurrence, identically or differently,
R 31 and R 32 are on each occurrence, identically or differently, H, F, Cl, CN, NCS, alkyl groups having 1 to 10 C atoms, alkoxy groups having 1 to 10 C atoms, thioalkoxy groups having 1 to 10 C atoms, alkenyl groups having 2 to 10 C atoms and alkenyloxy groups having 2 to 10 C atoms, where one or more H atoms in the alkyl, alkoxy, thioalkoxy, alkenyl or alkenyloxy groups may be replaced by F, Cl or CN;
Z 31 is on each occurrence, identically or differently, a single bond, —(C═O)—O—, —O—(C═O)—, —CF 2 —O—, —O—CF 2 —, —O—CH 2 —, —CH 2 —O— or —CH 2 —CH 2 —;
m is equal to 0, 1, 2 or 3;
where the sum of the proportions of the compounds of the formula (1), the compounds of the formula (2) and the compounds of the formula (3) in the mixture is at least 58%,
and where one or both of the following conditions a) and b) are satisfied:
a) the mixture comprises one or more compounds V which contain four or more rings,
b) the mixture comprises a proportion of at least 25% of compounds of the formula (2)
and
wherein said layer is present in a switchable window and said mixture has a clearing point of at least 105° C.
2. The switchable window according to claim 1 , wherein the compound of the formula (1) is a compound of formula (1-1)
where T, R 11 and R 12 are defined as in claim 1 .
3. The switchable window according to claim 1 , wherein the compound of the formula (2) is a compound of formula (2-1), (2-2), (2-3) or (2-4)
where R 21 , R 22 , A 21 , A 22 , A 23 , A 24 and T are defined as in claim 1 .
4. The switchable window according to claim 1 , wherein the compound of the formula (2) is a compound of formula (2-1-1)
where R 21 , R 22 and T are defined as claim 1 .
5. The switchable window according to claim 4 , wherein said mixture has a proportion of at least 25% of compounds of the formula (2-1-1).
6. The switchable window according to claim 1 , wherein the compound V is a compound of formula (V-1)
where
Z vi is from —(C═O)—O or —CH 2 —O—, and where
AV 1 is on each occurrence, identically or differently, from
and where R v1 and R V2 are on each occurrence, identically or differently, from H, F, Cl, CN, NCS, alkyl groups having 1 to 10 C atoms, alkoxy groups having 1 to 10 C atoms, thioalkoxy groups having 1 to 10 C atoms, alkenyl groups having 2 to 10 C atoms and alkenyloxy groups having 2 to 10 C atoms, where one or more H atoms in the alkyl, alkoxy, thioalkoxy, alkenyl or alkenyloxy groups may be replaced by F, Cl or CN.
7. The switchable window according to claim 1 , wherein the compound of the formula (3) is a compound of formulae (3-A), (3-B) or (3-C)
where R 31 , R 32 , Z 31 and A 31 are defined as in claim 1 .
8. The switchable window according to claim 1 , wherein A 31 in formulae (3) is on each occurrence,
identically or differently,
9. The switchable window according to claim 1 , wherein it comprises one or more compounds of the formula (3-1)
where R 31 , R 32 , Z 31 and m are defined as in claim 1 , and where A 31-1 is on each occurrence, identically or differently,
10. The switchable window according to claim 1 , wherein said mixture comprises both one or more compounds of the formula (1) and also one or more compounds of the formula (2).
11. The switchable window according to claim 1 , wherein compounds of the formula (1) are present in the mixture in a proportion of at least 25%.
12. The switchable window according to claim 1 , wherein compounds of the formula (2) are present in the mixture in a proportion of at least 25%.
13. The switchable window according to claim 1 , wherein the sum formed from the proportions of the compounds of the formula (1), formula (2) and formula (3) in said mixture is greater than 95%.
14. The switchable window according to claim 1 , wherein said mixture comprises a proportion of less than 60% of compounds which contain one or more benzene rings.
15. The switchable window according to claim 1 , wherein said mixture further comprises one or more dyes.
16. The switchable window according to claim 1 , wherein it comprises one or more dyes that are azo compounds, anthraquinones, benzothiadiazoles, diketopyrrolopyrroles or rylenes.
17. The switchable window according to claim 1 , wherein said mixture has a value of Δn of less than 0.065.
18. The switchable window according to claim 1 , wherein said mixture has a value of Δn of less than 0.055.
19. The switchable window according to claim 16 , wherein said mixture comprises at least dye which absorbs blue light, at least one dye which absorbs green to yellow light and at least one dye which absorbs red light.
20. The switchable window according to claim 1 , wherein said clearing point is of at least 110° C.