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Liquid crystal film and preparation method and application thereof

A liquid crystal thin film and liquid crystal technology, applied in the field of liquid crystal thin film and its preparation based on irreversible light regulation of chiral molecules, can solve the problems of poor stability and no use value, etc., achieve wide application, realize recording and hiding, and simple preparation method Effect

Active Publication Date: 2019-01-25
BEIJING UNIV OF CHEM TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, after recording the characters or patterns to be displayed, the liquid crystal display needs to be stored in a dark field environment, the stability is extremely poor, and it is basically useless. In addition, the characters or patterns after burning can be recognized with the naked eye under fluorescent lamps, which is obviously different from The purpose of this application to hide the anti-counterfeiting mark is contrary to

Method used

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  • Liquid crystal film and preparation method and application thereof
  • Liquid crystal film and preparation method and application thereof
  • Liquid crystal film and preparation method and application thereof

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0048] Embodiment 1 Preparation of liquid crystal film 1

[0049] 23 parts of nematic liquid crystal C6M, 40 parts of HCM-021 and 30 parts of HCM-020, 5 parts of non-photoresponsive chiral additive S1011, 2 parts of chiral photoswitching molecule 2, 2 parts of photoinitiator Irgacure819, ultraviolet inhibitor Add 2 parts of 4-methoxyphenol and 6 parts of fluorescent dye coumarin into dichloromethane solvent, stir for 2 hours, mix evenly, put them in a vacuum oven for drying, and obtain liquid crystal powder. Use a polarizing microscope with a hot stage to observe that the phase transition temperature of the liquid crystal is 60-75°C. Preheat the planar-oriented substrate to 60°C, pour it into the liquid crystal, then cool it down to 40°C, keep it for 5 minutes, and irradiate it with visible light for 5 minutes. liquid crystal film. Cover the film with a mask with pattern information, irradiate with ultraviolet light for 5 minutes, and the light intensity is 35mw / cm 2 Burn pa...

Embodiment 2

[0050] Preparation of Embodiment 2 Liquid Crystal Film 2

[0051] 20 parts of nematic liquid crystal C6M, 40 parts of HCM-021 and 30 parts of HCM-020, 7 parts of non-photoresponsive chiral additive R1011, 2 parts of chiral photoswitching molecule, 2 parts of photoinitiator Irgacure819, ultraviolet inhibitor 2 parts of 4-methoxyphenol and 1 part of fluorescent dye BBOT were added to the chloroform solvent, stirred for 2 hours, mixed evenly, and dried in a vacuum oven to obtain liquid crystal powder. Use a polarizing microscope with a hot stage to observe that the phase transition temperature of the liquid crystal is 60-80°C, preheat the planar-oriented substrate to 65°C, pour the liquid crystal, then cool down to 40°C, keep it for 5 minutes, and irradiate it with visible light for 5 minutes to obtain liquid crystal film. Cover the film with a mask with pattern information, irradiate with ultraviolet light for 5 minutes, and the light intensity is 40mw / cm 2 Burn the pattern in...

Embodiment 3

[0052] Embodiment 3 Preparation of Liquid Crystal Film 3

[0053] On the basis of Example 2, the types of chiral optical switch molecules were changed, and azobenzene compounds and chiral helicene molecules were added at the same time. Specifically, 1 part of chiral optical switch molecules and 6 parts of chiral optical switch molecules were added. Part, other components and preparation method thereof are all identical with comparative example 2. Burn the anti-counterfeiting two-dimensional code pattern information logo on the liquid crystal film, irradiate with ultraviolet light for 5 minutes, and the light intensity is 40mw / cm 2 . After burning, only a complete blank blue film can be seen under white light, and the two-dimensional code information hidden in the film can be seen under ultraviolet light, such as figure 1 As shown, it shows that the scheme can be used for burning anti-counterfeiting information.

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Abstract

The invention discloses a liquid crystal film. The liquid crystal film is prepared from nematic phase liquid crystals, chiral light switch molecules, organic fluorescent dye, a photo initiator and anultraviolet inhibitor and any added or non-added non-photoresponse chiral additives, wherein the chiral light switch molecules are heterogenous under ultraviolet irradiation, the arrangement of the chiral light switch molecules changes, the light emitting intensity of the organic fluorescent dye is affected, and different patterns with different fluorescent strengths appear in a place irradiated by ultraviolet light and a place not irradiated by ultraviolet light, so that the different patterns are fixed through an ultraviolet inhibitor. The liquid crystal film can be used for performing anti-fake recognition and / or information recording, anti-fake identifiers can be clearly read and can stably exist for a long time, and reversible changes cannot happen due to illumination and other reasons.

Description

technical field [0001] The invention belongs to the field of liquid crystal materials and applications thereof, and in particular relates to a liquid crystal film based on chiral molecule irreversible light regulation and a preparation method thereof. Background technique [0002] Liquid crystal has both the isotropy of liquid and the order of crystal. It is a partially ordered substance composed of rod-shaped molecules, disc-shaped molecules and other molecules that do not have spherical symmetry. Liquid crystals not only have the flow characteristics of fluids, but also can exhibit the inherent spatial anisotropy of crystals, including spatial anisotropy of dielectric, magnetic polarization, and optical refractive index. It is precisely because of these special properties that liquid crystals are widely used in the fields of optical storage, optical display, optical switches, etc., but there are few existing technologies that use liquid crystals in the field of anti-counte...

Claims

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Application Information

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IPC IPC(8): G02F1/13G09F3/00C08J5/18C08L33/14
CPCC08J5/18C08J2333/14G02F1/1313G09F3/0291
Inventor 魏杰许琳琳
Owner BEIJING UNIV OF CHEM TECH