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CN-121991525-A - Dichroic dye, liquid crystal composition and application thereof

CN121991525ACN 121991525 ACN121991525 ACN 121991525ACN-121991525-A

Abstract

The invention discloses a dichroic dye, a liquid crystal composition and application thereof. The disclosed dichroic dye compound has a structural general formula shown as I, and the disclosed liquid crystal composition comprises the dichroic dye and at least one liquid crystal compound. The dimming glass device prepared by the dichroic dye related liquid crystal composition has the advantages of high photo-thermal stability, high order parameter and wide working temperature range.

Inventors

  • LI JIAN
  • Wan danyang
  • WU YIN
  • Bai pujiang
  • HU ZHIGANG
  • ZHANG LU
  • YANG CHENG
  • LI JUANLI
  • HU MINGGANG
  • MO LINGCHAO
  • CHE ZHAOYI
  • Liang Lexuan
  • SHI FENGJIAO

Assignees

  • 西安近代化学研究所

Dates

Publication Date
20260508
Application Date
20241108

Claims (13)

  1. 1. A dichroic dye characterized by having the structural formula I: In formula I: W is an oxygen atom, a sulfur atom or a selenium atom; X is C-L 2 or a nitrogen atom; l 1 、L 2 is independently a hydrogen atom, a fluorine atom, a chlorine atom, an alkyl group having 1 to 6 carbon atoms or a cyano group; Y is 0,1 or 2; Each of a 1 and a 2 is independently represented by a group represented by the following structure: Wherein each L 3 、L 4 independently represents a hydrogen atom, a fluorine atom, a chlorine atom, an alkyl group having 1 to 7 carbon atoms, or a cyano group; Each of a 3 and a 4 is independently an aromatic ring, a hydrogenated quinoline ring, a hydrogenated benzopyran ring, a hydrogenated naphthalene ring, a hydrogenated benzoxazine ring, a hydrogenated benzothiazine ring, or a hydrogenated quinoxaline ring represented by the following structure: And at least one of A 3 and A 4 is selected from a hydrogenated benzoxazine ring, a hydrogenated benzothiazine ring or a hydrogenated quinoxaline ring; Wherein R 1 ,R 2 ,R 3 ,R 4 ,R 6 and R 7 are each independently a hydrogen atom or an alkyl group having 1 to 7 carbon atoms, R 5 is a hydrogen atom, a fluorine atom, a chlorine atom, a methyl group or an ethyl group, R 8 is a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, -NHR 9 or-N (R 9 ) 2 ;R 9 is an alkyl group having 1 to 10 carbon atoms).
  2. 2. The dichroic dye according to claim 1, wherein W is a sulfur atom, and rings a 1 and a 2 are each independently represented as a benzene ring or a thiophene ring.
  3. 3. The dichroic dye according to claim 2, wherein the dichroic dye is selected from one of the structural general formulas I-1~I-21:
  4. 4. A liquid crystal composition comprising a dichroic dye of the general structural formula I and one or more liquid crystal compounds.
  5. 5. The liquid crystal composition of claim 4, further comprising one or more chiral compounds.
  6. 6. The liquid crystal composition of claim 4, further comprising one or more heat stabilizers or light stabilizers.
  7. 7. The liquid crystal composition according to claim 4, wherein the liquid crystal compound is selected from the group consisting of liquid crystal compounds represented by the general structural formula II: In formula II: r is an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms or a cycloalkyl group having 3 to 6 carbon atoms; ring a, ring B, ring C are each independently cyclohexane, cyclohexene, a benzene ring, a tetrahydropyran ring, or a benzene ring in which a hydrogen atom is substituted with fluorine; X 0 is hydrogen, fluorine, chlorine, cyano, trifluoromethoxy, trifluoromethyl, alkyl having 1 to 10 carbon atoms, alkoxy having 1 to 10 carbon atoms, alkenyl having 2 to 10 carbon atoms or cycloalkyl having 3 to 6 carbon atoms; each X 1 、X 2 、X 3 is independently hydrogen or fluorine; x 4 is a single bond, -COO-, -CH 2 CH 2 -, or-CF 2 O-; k. p and q are each independently 0,1,2, and k+p+q is not less than 1.
  8. 8. The liquid crystal composition according to claim 7, wherein the liquid crystal compound is selected from the group consisting of liquid crystal compounds of the general structural formula III: In formula III: r' is an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms or a cycloalkyl group having 3 to 6 carbon atoms; ring A is cyclohexane, cyclohexene, benzene ring, tetrahydropyran ring or benzene ring with hydrogen atom replaced by fluorine; x 0 ' is hydrogen, fluorine, chlorine, cyano, trifluoromethoxy, trifluoromethyl, alkyl having 1 to 10 carbon atoms, alkoxy having 1 to 10 carbon atoms, alkenyl having 2 to 10 carbon atoms or cycloalkyl having 3 to 6 carbon atoms; x 4 ' is a single bond, -COO-, -CH 2 CH 2 -、-CF 2 O-or-CH 2 O-; x 5 ' is an oxygen atom or a sulfur atom, and k is 0,1,2.
  9. 9. The liquid crystal composition according to claim 4, wherein the mass percentage of the dichroic dye represented by the structural formula I is 0.1% -10%, the mass percentage of the liquid crystal compound represented by the structural formula II is 80% -99.9%, and the mass percentage of the liquid crystal compound represented by the structural formula III is 0% -19.9%.
  10. 10. The liquid crystal composition according to claim 5, wherein the chiral compound is added in an amount of 0.01% to 5% by mass based on the total mass of the dichroic dye and the liquid crystal compound.
  11. 11. The liquid crystal composition according to claim 6, wherein the added mass of the heat stabilizer or the light stabilizer is 0.001% to 1% of the total mass of the dichroic dye and the liquid crystal compound.
  12. 12. Use of a liquid crystal composition according to any one of claims 4 to 11 for the preparation of a light-modulating glass device.
  13. 13. A light-adjusting glass device, characterized in that the raw materials for producing the light-adjusting glass device comprise the liquid crystal composition according to any one of claims 4 to 11.

Description

Dichroic dye, liquid crystal composition and application thereof Technical Field The invention belongs to the technical field of liquid crystal materials, and particularly relates to a dichroic dye with high stability, large extinction coefficient, high solubility and high order parameter, a synthesis method thereof, a liquid crystal composition containing the dichroic dye, a dimming glass device, a polaroid and application. Background The dimming glass can realize controllable adjustment of ultraviolet light, visible light and even infrared light waves, and has wide application prospects in building daylighting glass, automobile windows and the like. The energy consumption of an air conditioner and the like can be reduced by regulating and controlling the input light and heat energy through the dimming glass, and energy conservation and emission reduction are realized. The current dimming glass scheme comprises dye liquid crystal, PDLC (polymer dispersed liquid crystal), EC (electrochromic), SPD (suspended particles) and other technical schemes. The EC (electrochromic) principle is that the redox reaction realizes color-changing dimming, but the response speed is slower (5 min/m 2), and the larger the glass size is, the slower the color change is, and the phenomenon of uneven color change is easy to occur. The PDLC (polymer dispersed liquid crystal) dimming glass is powered on and transparent, and is powered off to be in a fog state, so that the application scene of the PDLC is limited due to larger fog degree, and the PDLC is suitable for meeting room partitions and the like, and is limited in application scenes such as window glass and the like. SPD (suspended particle) dimming glasses have an operating voltage of up to 110V, which presents a safety risk, and thus are of great limitation in application to vehicle glazing. The dimming glass based on dye liquid crystal has the advantages of electrodeless dimming and second-level response, low driving voltage (< 12V), 2w/m 2 of power consumption, energy conservation and consumption reduction, high permeability, small haze and no viewing angle. Thus, dye liquid crystal based dimming glasses have significant technical advantages over other dimming glass technologies. The working principle of the dye liquid crystal dimming glass is a guest-host mode, which is favorable for the difference of light absorption of the long axis and the short axis of the dichroic dye molecules and realizes the absorption and adjustment of light. The properties of dichroic dyes, in particular the light stability, extinction coefficient, solubility, absorption spectrum range, anisotropy of absorption spectrum, order parameters, etc., play a decisive role in the performance and long-term use reliability of dye liquid crystal light-adjusting glass devices. Although the dichroic dye based on azo structure has higher order parameters, the ultraviolet light stability of azo dye is poor, and long-term stable application is difficult to realize. Patent CN105377995A discloses dichroic dyes based on benzothiadiazole parent core units, which have a high degree of light stability, but the extinction coefficient of such dyes is relatively low. Since the extinction coefficient of the dichroic dye is relatively low, the dye in the liquid crystal composition needs more addition amount, and the dimming requirement can be satisfied. However, as the amount of the dichroic dye increases, a series of problems such as cost increase, viscosity increase, compatibility and the like are further caused. Furthermore, patent CN105377995A discloses dichroic dyes based on a benzothiadiazole mother core unit, which also have poor solubility, and is greatly limited in application, such as the following molecular structure comprising a benzothiadiazole unit: the solubility of the dye (1) in the mother liquid crystal is less than 0.25%, the solubility of the dye (2) in the mother liquid crystal is 0.3%, and the solubility of the dye (3) in the mother liquid crystal is 0.3%. Because of extremely low solubility, it is difficult to meet the application requirements of dimming glass and the like. Disclosure of Invention In order to overcome the defects or shortcomings in the background art, the invention provides a dichroic dye with high light stability, large extinction coefficient, high solubility, high order parameter and large absorption peak width. In order to achieve the above task, the structure of the dichroic dye compound provided by the invention is shown as a general formula I: In formula I: W is an oxygen atom, a sulfur atom or a selenium atom; X is C-L 2 or a nitrogen atom; l 1、L2 is independently a hydrogen atom, a fluorine atom, a chlorine atom, an alkyl group having 1 to 6 carbon atoms or a cyano group; Y is 0,1 or 2; Each of a 1 and a 2 is independently represented by a group represented by the following structure: Wherein each L 3、L4 independently represents a hydrogen atom, a fluorine atom, a chlorine