Switch element comprising a liquid-crystalline medium

Abstract

The present invention relates to a switch element, which is thermoresponsive and which switches between a less transmissive state for radiant energy and a more transmissive state for radiant energy, and which comprises a liquid-crystalline medium. The invention furthermore relates to the use of the switch element for the regulation of radiant energy flow between interior spaces and the environment and for the regulation of the temperature of interior spaces. The invention furthermore relates to a liquid-crystalline medium, characterised in that it comprises 5-95% of a compound of the formula (I), in particular for use in the switch elements according to the invention.

Claims

1. Switch element, characterised in that it is thermoresponsive and that it switches between a less transmissive state for radiant energy and a more transmissive state for radiant energy, comprising a liquid-crystalline medium, which comprises one or more compounds of the formula (I) ##STR00363## where R.sup.11,R.sup.12 are on each occurrence, identically or differently, F, Cl, CN, NCS, R.sup.1OCO, R.sup.1COO, an alkyl, alkoxy or thioalkoxy group having 1 to 10 C atoms, or an alkenyl, alkenyloxy or thioalkenyloxy group having 2 to 10 C atoms, or a monocyclic, bicyclic or tricyclic cycloalkyl or cycloalkenyl group having 3 to 10 C atoms, where one or more H atoms in the groups mentioned above may be replaced by F, Cl, CN, and where one or more CH.sub.2 groups in the groups mentioned above may be replaced by O, S, OCO or COO; and where R.sup.1 is, identically or differently on each occurrence, an alkyl or an alkenyl group having 1 to 10 C atoms, in which one or more H atoms may be replaced by F or Cl; and ##STR00364## is selected from ##STR00365## is selected from ##STR00366## and X is on each occurrence, identically or differently, F, Cl, CN or an alkyl, alkoxy or thioalkoxy group having 1 to 10 C atoms, where one or more H atoms in the groups mentioned above may be replaced by F or Cl and where one or more CH.sub.2 groups may be replaced by O or S; and Z.sup.11 is selected from CF.sub.2O, OCF.sub.2, CH.sub.2CH.sub.2, CF.sub.2CF.sub.2, OCH.sub.2, CH.sub.2O, O, and a single bond.

2. Switch element according to claim 1, characterised in that the liquid-crystalline medium furthermore comprises one or more compounds of the formula (II), where in one embodiment of the invention, a compound according to formula (II) is a compound of the following formula (II-1) ##STR00367## where R.sup.21,R.sup.22 are on each occurrence, identically or differently, selected from F, Cl, CN, NCS, R.sup.1OCO, R.sup.1COO, an alkyl, alkoxy or thioalkoxy group having 1 to 10 C atoms and an alkenyl, alkenyloxy or thioalkenyloxy group having 2 to 10 C atoms, where one or more H atoms in the groups mentioned above may be replaced by F or Cl, and where one or more CH.sub.2 groups in the groups mentioned above may be replaced by O, S, OCOor COO; and R.sup.1 is defined as in claim 1; and ##STR00368## are, identically or differently, selected from ##STR00369## where Z.sup.21 is selected from CF.sub.2O, OCF.sub.2, CH.sub.2CH.sub.2, CF.sub.2CF.sub.2, OCH.sub.2, CH.sub.2O, O, and a single bond; and where, in an alternative embodiment of the invention, a compound according to formula (II) is a compound of the following formula (II-2) ##STR00370## where R.sup.21,R.sup.22 are on each occurrence, identically or differently, selected from F, Cl, CN, NCS, R.sup.1OCO, R.sup.1COO, an alkyl, alkoxy or thioalkoxy group having 1 to 10 C atoms and an alkenyl, alkenyloxy or thioalkenyloxy group having 2 to 10 C atoms, where one or more H atoms in the groups mentioned above may be replaced by F or Cl, and where one or more CH.sub.2 groups in the groups mentioned above may be replaced by O, S, OCO or COO; and R.sup.1 is defined as in claim 1; and ##STR00371## are, identically or differently, selected from ##STR00372## where X is defined as in claim 1; and Z.sup.22 is selected from CF.sub.2O, OCF.sub.2, CH.sub.2CH.sub.2, CF.sub.2CF.sub.2, OCH.sub.2, CH.sub.2O, O, and a single bond; and where, in an alternative embodiment of the invention, a compound according to formula (II) is a compound of the following formula (II-3) ##STR00373## where R.sup.21,R.sup.22 are on each occurrence, identically or differently, selected from F, Cl, CN, NCS, R.sup.1OCO, R.sup.1COO, an alkyl, alkoxy or thioalkoxy group having 1 to 10 C atoms and an alkenyl, alkenyloxy or thioalkenyloxy group having 2 to 10 C atoms, where one or more H atoms in the groups mentioned above may be replaced by F or Cl, and where one or more CH.sub.2 groups in the groups mentioned above may be replaced by O, S, OCO or COO; and R.sup.1 is defined as in claim 1; and ##STR00374## are, identically or differently, selected from ##STR00375## where Y is on each occurrence, identically or differently, selected from H and X; X is defined as in claim 1; and Z.sup.23 is selected from CF.sub.2O, OCF.sub.2, CH.sub.2CH.sub.2, CF.sub.2CF.sub.2, OCH.sub.2, CH.sub.2O, O, COO, OCO, CHCH, CHCX, CXCH and CXCX and a single bond; with the proviso that at least one of ##STR00376## is selected from ##STR00377## and where, in an alternative embodiment of the invention, a compound according to formula (II) is a compound of the following formula (II-4) ##STR00378## where R.sup.21,R.sup.22 are on each occurrence, identically or differently, selected from F, Cl, CN, NCS, R.sup.1OCO, R.sup.1COO, an alkyl, alkoxy or thioalkoxy group having 1 to 10 C atoms and an alkenyl, alkenyloxy or thioalkenyloxy group having 2 to 10 C atoms, where one or more H atoms in the groups mentioned above may be replaced by F or Cl, and where one or more CH.sub.2 groups in the groups mentioned above may be replaced by O, S, OCO or COO; and R.sup.1 is defined as in claim 1; and ##STR00379## are, identically or differently, selected from ##STR00380## where X is defined as in claims 1; and Z.sup.24 is selected from COO, OCO, CHCH, CHCX, CXCH and CXCX.

3. Switch element according to claim 2, characterised in that the liquid-crystalline medium furthermore comprises one or more compounds selected from compounds of the formulas (III) and (IV) ##STR00381## where R.sup.31,R.sup.32,R.sup.41 and R.sup.42 have the meanings indicated for R.sup.21 and R.sup.22 in claim 2; and ##STR00382## are on each occurrence, identically or differently, selected from ##STR00383## where X and Y are defined as in claim 2; and Z.sup.31 and Z.sup.32 are on each occurrence, identically or differently, selected from COO, OCO, CF.sub.2O, OCF.sub.2, CH.sub.2CH.sub.2, OCH.sub.2, CH.sub.2O and a single bond; and Z.sup.41 , Z.sup.42 and Z.sup.43 are on each occurrence, identically or differently, selected from COO, OCO and a single bond.

4. Switch element according to claim 1, characterised in that compounds according to formula (I) are compounds of the following formulas (I-1) to (I-2) ##STR00384## being selected from ##STR00385## being selected from ##STR00386## and where X and R.sup.11 and R.sup.12 are defined as in claim 1.

5. Switch element according to claim 2, characterised in that compounds according to formula (II-1) are compounds of the following formula (II-1a) ##STR00387## where R.sup.21 and R.sup.22 are defined as in claim 2.

6. Switch element according to claim 2, characterised in that compounds according to formula (II-2) are compounds of the following formula (II-2a) ##STR00388## where R.sup.21 and R.sup.22 are defined as in claim 2.

7. Switch element according to claim 2, characterised in that compounds according to formula (II-4) are compounds of the following formulas (II-4a) to (II-4g) ##STR00389## where X is defined as in claim 1 and R.sup.21 and R.sup.22 are defined as in claim 2.

8. Switch element according to claim 3, characterised in that compounds according to formula (III) are compounds of the following formulas (III-1) to (III-3) ##STR00390## where the groups R.sup.31, R.sup.32, and ##STR00391## are defined as in claim 3; and Z.sup.31and Z.sup.32 are, identically or differently on each occurrence, COO, OCO, CF.sub.2O or CH.sub.2CH.sub.2.

9. Switch element according to claim 3, characterised in that compounds according to formula (IV) are compounds of the following formulas (IV-1) and (IV-2) ##STR00392## where R.sup.41 and R.sup.42 and ##STR00393## are defined as in claim 3.

10. Switch element according to claim 1, characterised in that X is selected from F and Cl.

11. Switch element according to claim 1, characterised in that the total concentration of the compounds according to formula (I) is between 15 and 90%.

12. Switch element according to claim 1, characterised in that no electrical wiring, circuitry and/or switching network is present in the switch element.

13. A thermoresponsive optical switch element comprising a liquid-crystalline medium having a phase transition temperature between 20 C. and 50 C., comprising one or more compounds according to formula (I-1a-3) in a total concentration of 5 to 95%, and at least one further compound of the formula (II-2a-2) ##STR00394## wherein R.sup.21 is, identically or differently on each occurrence, an alkyl group having 1 to 10 C atoms, where one or more CH.sub.2 groups may be replaced by OCO or COO so that the total concentration of the compounds of the formulas (I-1a-3), and (II-2a-2) is between 40 and 100%; wherein the compound of formula (I-1a-3), is of the formula: ##STR00395## wherein R.sup.11 is, identically or differently on each occurence, an alkyl group having 1 to 10 C atoms, where one or more CH.sub.2 groups may be replaced by OCO or COO.

14. A method for the regulation of the flow of radiant energy between an interior space and the environment comprising a switch element according to claim 1.

Description

EXAMPLES

(1) The following exemplary liquid-crystalline mixtures are listed for the purpose of illustrating the present invention and are not to be understood as limiting it in any way.

(2) The compositions of the liquid-crystalline mixtures are listed below together with their clearing points and their long-term-storage behaviour. The person skilled in the art learns from the data given below which properties can be obtained with the mixtures according to the invention. He is furthermore taught how the composition of the mixtures can be modified in order to obtain the desired properties, in particular a defined temperature of the clearing point and high long-term stability.

(3) Liquid crystal mixtures with the compositions listed in the following tables are prepared, and their clearing points and long-term-storage behaviour are determined.

(4) As stated in the description part of the present application, the clearing point of the liquid-crystalline media according to the invention is preferably between 20 and 80 C., more preferably between 10 and 60 C. and most preferably between 20 and 50 C. Even more preferably, the clearing point is between 20 and 40 C.

(5) Exemplary mixtures with a relatively high clearing point (>70 C., in particular >80 C.) are preferably used as a so-called two-bottle system in combination with a mixture having a lower clearing point.

(6) 1) Examples for Liquid-crystalline Medium I

(7) TABLE-US-00008 Example-1 Example-2 Clearing 60 C. 28 C. point Storage >1000 h >1000 h stability at 40 C. Substance % Substance % CP-3-N 16 CP-3-N 16 PP-2-N 8 CP-4-N 6 PP-3-N 8 CP-5-N 14 PP-4-N 8 PP-2-N 8 PZP-1-5 13 PP-3-N 8 PZP-3-5 12 PP-4-N 8 PZP-5-5 12 PZP-1-5 13 CPZP-5-N 10 PZP-3-5 12 CPZP-3-3 4 PZP-5-5 12 CPZP-5-3 5 CPZP-5-N 3 CPZIC-3-5 4 sum 100 100 Example-3 Example-4 Clearing 67.5 C. 31.5 C. point Storage >1000 h >1000 h stability at 40 C. Substance % Substance % CP-3-N 13 CP-3-N 13 CP-3-O2 5 CP-5-N 16 PP-2-N 7 CP-3-O2 18 PP-3-N 5 PP-2-N 7 PZP-2-N 4 PP-3-N 5 PZP-3-N 3 PZP-2-N 4 PZG-2-N 3 PZP-3-N 3 PZG-3-N 4 PZG-2-N 3 PZG-5-N 6 PZG-3-N 4 CZP-3-O1 6 PZG-5-N 6 CZP-3-O2 8 CZP-3-O1 6 CZP-4-O1 7 CZP-3-O2 8 CZP-4-O2 5 CZP-4-O1 7 CPP-3-2 10 CPP-5-2 8 CPZP-3-3 6 sum 100 100
2) Examples for Liquid-crystalline Medium II

(8) TABLE-US-00009 Example-5 Example-6 Clearing 68 C. 35 C. point Storage >1000 h >1000 h stability at 40 C. Substance % Substance % CP-2-N 10 CP-2-N 10 CP-4-N 10 CP-4-N 10 PZG-2-N 5 CP-5-3 15 PZG-3-N 5 PZG-2-N 2 PZG-5-N 5 PZG-3-N 3 CZP-5-5 7 PZG-4-N 5 CZP-3-O1 7 PZG-5-N 5 CZP-3-O2 7 CZP-5-5 7 CZP-4-O1 7 CZP-3-O1 7 CZP-4-O2 7 CZP-3-O2 7 CZP-5-O1 7 CZP-4-O1 7 CZP-5-O2 6 CZP-4-O2 7 CPZP-3-3 6 CZP-5-O1 7 CPZP-5-3 6 CZP-5-O2 6 CPP-5-2 5 CPP-5-2 2 sum 100 100 Example-7 Example-8 Clearing 67 C. 30.5 C. point Storage >1000 h >1000 h stability at 40 C. Substance % Substance % CP-3-N 18 CP-3-N 18 CP-5-N 9 CP-5-N 9 PZG-2-N 4 CP-3-O1 19 PZG-3-N 4 PZG-2-N 4 PZG-5-N 5 PZG-3-N 4 PZP-2-N 5 PZG-5-N 5 PZP-3-N 5 PZP-2-N 5 PZP-10-5 11 PZP-3-N 5 CZP-3-O2 10 PZP-10-5 11 CZP-5-O1 10 CZP-3-02 10 CPZG-3-N 4 CZP-5-O1 10 CPZG-4-N 4 CPZIC-3-4 4 CPZIC-3-5 7 sum 100 100
3) Examples for Liquid-crystalline Medium III

(9) TABLE-US-00010 Example-9 Example-10 Clearing 69.5 C. 35 C. point Storage >1000 h >1000 h stability at 40 C. Substance % Substance % CP-2-N 13 CP-2-N 13 CP-3-N 8 CP-3-N 13 CU-3-N 5 CU-3-N 13 CC-5-V 20 CP-3-O1 11 CC-1V-V1 8 CC-5-V 20 CC-3-4 3 CC-1V-V1 8 CC-3-O2 3 CC-3-4 3 CCP-V-1 8 CC-3-O2 3 CCP-2-OT 9 CCP-2-OT 4 CCP-3-OT 7 CCP-3-OT 4 CCZU-2-F 7 CCZU-2-F 4 CCZU-3-F 5 CPP-3-2 4 CPP-3-2 4 sum 100 100 Example-11 Example-12 Clearing 68.5 C. 33 C. point Storage >1000 h >1000 h stability at 40 C. Substance % Substance % CY-3-O4 13 CY-3-O4 13 CY-5-O2 12 CY-5-O2 12 CY-5-O4 16 CY-5-O4 16 CC-3-5 5 CP-3-O1 10 CC-5-V 9 CP-3-O2 12 CC-3-V1 8 CC-3-O3 9 CCY-1-O4 10 CC-5-V 5 CCY-3-O2 12 CC-3-V1 4 CPY-2-O2 9 CC-3-5 4 CPY-3-O2 6 CPY-2-O2 9 CPY-3-O2 6 sum 100 100
4) Examples for Liquid-crystalline Medium IV

(10) TABLE-US-00011 Example-13 Example-14 Clearing 35 C. 32.5 C. point Storage >1000 h >1000 h stability at 40 C. Substance % Substance % CP-7-F 9 CP-7-F 4.5 CP-5-3 35 CP-3-2 4.5 CPG-3-F 4 CP-5-3 35 CPU-3-F 12 CPG-3-F 4 CPU-5-F 10 CPU-3-F 12 CCU-2-F 11 CPU-5-F 10 CCU-3-F 11 CCU-2-F 11 CPP-3-2 4 CCU-3-F 11 CPPC-3-3 2 CPP-3-2 4 CPPC-5-3 2 CPPC-3-3 2 CPPC-5-3 2 sum 100 100 Example-15 Clearing 7.5 C. point Storage >1000 h stability at 40 C. Substance % CP-7-F 4.5 CP-3-2 12.5 CP-5-3 35 CPG-3-F 4 CPU-3-F 12 CPU-5-F 10 CCU-2-F 11 CCU-3-F 11 sum 100
5) Examples for Liquid-crystalline Medium V

(11) TABLE-US-00012 Example-16 Example-17 Clearing 62 C. 35.5 C. point Storage >1000 h >1000 h stability at 40 C. Substance % Substance % CP-2-N 19 CP-2-N 19 CP-3-N 24 CP-3-N 24 CP-4-N 20 CP-4-N 20 CP-5-N 7 CP-5-N 7 CP-3-O1 12 CP-3-O1 12 CGPC-3-3 6 CP-5-3 6 CGPC-5-3 7 CPP-3-2 3 CGPC-5-5 5 CPP-5-2 6 CGPC-3-3 3 sum 100 100 Example-18 Example-19 Clearing 72 C. 36.5 C. point Storage >1000 h >1000 h stability at 40 C. Substance % Substance % CP-3-N 24 CP-3-2 20 CP-5-N 36 CP-5-3 12 CP-7-N 25 CP-3-O1 20 CPP-5-N 15 CP-3-O2 20 CPP-3-2 14 CPP-5-2 14 sum 100 sum 100
6) Examples for Liquid-crystalline Medium VI

(12) TABLE-US-00013 Example-20 Example-21 Clearing 59 C. 33 C. point Storage >1000 h >1000 h stability at 40 C. Substance % Substance % CP-3-N 14 CP-3-N 14 CP-4-N 8 CP-4-N 8 CP-5-N 15 CP-5-N 15 CP-7-N 8 CP-7-N 8 CP-3-O1 12 CP-3-O1 12 CP-3-O2 12 CP-3-O2 12 CP-3-O4 7 CP-3-O4 7 CPZC-2-3 6 CP-5-3 12 CPZC-4-3 6 CPZC-2-3 6 CCZC-3-3 6 CPZC-4-3 6 CCZC-3-5 6 sum 100 100
7) Use of Liquid-crystalline Media in Switch Elements

(13) The mixtures 1 to 21 according to the invention are employed as liquid-crystalline media in the switch element according to the procedure of US 2009/0015902.

(14) For assembling the switch element, the procedure described in paragraphs [0050]-[0055] of the above-mentioned patent application is followed, except that instead of the mixture disclosed in the application (5 parts 6CB (4-hexyl-4-cyanobiphenyl), 1.25 parts mixture E7 and 0.008 parts S-811) one of the exemplary mixtures of the present invention is used (example-1 to example-21).

(15) With the mixtures according to the invention (Example-1 to Example-21), switch elements with high operational lifetime can be obtained. The switch elements have a switching temperature which is close to the clearing point of the mixtures (10 C. to 80 C., which is in the preferred operating range of the elements).

(16) This shows that high device stability together with a controllable clearing point can be obtained with the mixtures according to the invention.

(17) These findings support the concept of the present invention for liquid-crystalline mixtures for use in switch elements.