Liquid crystal mixture and light modulating device using the same
11643600 · 2023-05-09
Assignee
Inventors
Cpc classification
G02F1/137
PHYSICS
C09K2323/00
CHEMISTRY; METALLURGY
C09K19/2007
CHEMISTRY; METALLURGY
C09K2019/0448
CHEMISTRY; METALLURGY
G02F1/13756
PHYSICS
C09K19/12
CHEMISTRY; METALLURGY
International classification
C09K19/12
CHEMISTRY; METALLURGY
C09K19/04
CHEMISTRY; METALLURGY
C09K19/18
CHEMISTRY; METALLURGY
C09K19/20
CHEMISTRY; METALLURGY
C09K19/30
CHEMISTRY; METALLURGY
G02F1/1337
PHYSICS
Abstract
A liquid crystal mixture applied in light modulating devices includes at least one compound selected from the group of compounds of formula I, at least one compound selected from the group of compounds of formula II and/or formula III, and at least one chiral compound. A light modulating device includes the liquid crystal mixture, where the light modulating device has reduced haze in the transparent state while increased opacity in the light scattering state.
R.sub.1-MG.sub.1-X-MG.sub.2-R.sub.2 I ##STR00001##
Claims
1. A liquid crystal mixture applied in light modulating devices, comprising: (a) at least two compounds selected from the group consisting of compounds of formulas I-1 to I-8, and I-10 ##STR00032## (b) at least one compound selected from the group consisting of compounds of formula II ##STR00033## (c) at least one compound selected from the group consisting of compounds of formula III ##STR00034## and (d) at least one chiral compound consisting of: ##STR00035## wherein H.sub.1, H.sub.2, H.sub.3, H.sub.4 and H.sub.5 each independently denote a ring structure selected from the group of ##STR00036## where one or more H atoms may be independently substituted by halogen, a alkyl group with 1-10 C atoms or a ester group, B.sub.1 and B.sub.2 each independently denote —COO—, —OCO—, —CF.sub.2O—, —OCF.sub.2—, —CH.sub.2O—, —OCH.sub.2—, —C≡C—, —CH═CH—, —CF.sub.2CF.sub.2—, —CF═CF—, a single bond or —(CH.sub.2).sub.a— where a is a even number between 2-10, A.sub.1, A.sub.2, A.sub.3 and A.sub.4 each independently denote —CN, —F, —Cl, —NCS, —OCF.sub.3, —CF.sub.3 or a chain alkyl group with 1-25 C atoms where one or more nonadjacent —CH.sub.2— may be independently replaced by —O—, —S—, —NH—, —N(CH.sub.3)—, —CO—, —COO—, —OCO—, —OCOO—, —SCO—, —COS—, —CH═CH—, —CH═CF—, —CF═CF— or —C≡C—, k is 1, 2, 3 or 4, m is 0, 1 or 2, n is 1, 2 or 3, o is 1 or 2, and m+n+o is no more than 5, and the at least two compounds of formulas I-1 to I-8, and I-10 is 1%-34% by weight of the liquid crystal mixture.
2. The liquid crystal mixture as defined in claim 1, further comprising at least one polymerizable monomer.
3. The liquid crystal mixture as defined in claim 2, further comprising at least one polymerization initiator.
4. The liquid crystal mixture as defined in claim 1, wherein the at least two compound of formulas I-1 to I-8, and I-10 is 10%-34% by weight of the liquid crystal mixture.
5. A light modulating device comprising the liquid crystal mixture as defined in claim 1, including two stable states: the transparent state where substantially all the incident light goes through and the light scattering state where substantially all the incident light is scattered, wherein the transparent state and the light scattering state may be switched by applying electrical field.
6. The light modulating device as defined in claim 5, wherein the haze of the transparent state is no more than 15%.
7. The light modulating device as defined in claim 5, wherein the haze of the light scattering state is no less than 80%.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
(1) These and other features and advantages of the present invention will be better understood by reference to the following detailed description of an illustrative embodiment of the present disclosure when read in conjunction with the accompanying drawings, wherein:
(2)
(3)
(4)
DETAILED DESCRIPTION OF THE INVENTION
(5) The following description of the disclosed embodiments is provided in detail to enable any person skilled in the art to fully understand the present invention. However, it will be apparent to those skilled in the art to readily make or use the present invention without these specific details. In other examples, well-known structures and devices are shown in the block diagram. In this regard, the description of the different illustrative exemplary embodiments presented herein are for the purpose of illustration and description and are not intended to be exhaustive or limited to the inventive concept. Accordingly, the scope of the invention is not to be limited by the specific embodiments described above, and is subject only to the scope of the appended claims.
(6) The component used in following examples can be either synthesized through a known method or purchased from markets. These synthetic methods are conventional and each of the obtained liquid crystal compounds has been tested to meet the standards of electronic compounds.
(7) A liquid crystal mixture was prepared in accordance with the ratio specified in the following examples. The preparation is carried out in accordance with a conventional method in the art. In detail, each component is weighed according to its corresponding mass percentage, and placed in a glass bottle. After a magnetic stirring bar is added, the bottle is placed on a heating magnetic stirrer, and the liquid crystal mixture is heated and stirred until completely melting to form an isotropic transparent solution. The temperature at this point has reached the clear point of the liquid crystal mixture. If the liquid crystal mixture contains a light-sensitive polymerizable monomer, after the polymerizable monomer is added, the liquid crystal mixture must be heated to the clear point in the dark. The liquid crystal mixture continues to be heat in the temperature for 30 minutes to ensure uniform mixing, and then the liquid crystal continues to be stirred for another 2 hours.
(8) After that, the uniformly mixed liquid crystal mixture is poured into an empty liquid crystal cell prepared according to various design requirements by a vacuum-filled method, and then the cell is sealed by a UV adhesive, forming a light modulating device. The light modulating device has two stable states: a transparent state and a light scattering state. In the transparent state, the chiral nematic liquid crystal (cholesteric liquid crystal) molecules are substantially aligned parallel to the device substrate, and the helical axis thereof is perpendicular to the device substrate to form the planar texture of cholesteric liquid crystal. In this state, the incident light transmits through the light modulating device substantially unaffected. While in the light scattering state, the cholesteric liquid crystal molecules form a focal conic texture, and the incident light is substantially scattered, causing large haze. By selecting a suitable driving voltage, the light modulating device may be switched between the transparent state and the light scattering state, where the haze is measured using a WGT-S type haze meter to determine its optical performance.
(9) The structure of the light modulating device is shown in
(10) In some embodiments, a first alignment layer 106 may be disposed between the first electrode 104 and the liquid crystal layer 103, as shown in
(11) In the following examples, the group structures of the liquid crystal molecules are represented by the codes listed in Table 1, and the codes and structures of some additives are listed in Table 2. The ratios all refer to mass percentages, and the alignment layer or the transparent substrate located on opposite sides of the liquid crystal layer 103 is rubbed in an anti-parallel manner.
(12) TABLE-US-00001 TABLE 1 the code for groups of liquid crystal Code Group structure E
where, if n or m is 3, the group is —C.sub.3H.sub.7.
(13) TABLE-US-00002 TABLE 2 The code and structure of other additives Code Structure R01
COMPARATIVE EXAMPLE
(14) TABLE-US-00003 TABLE 3 formula of liquid crystal mixture Component Ratio/% 2PPN 7.6 5PPN 21.8 5OPPN 16.8 6OPPN 7.9 3PP.sup.11PN 16.8 5HPPN 8.9 5PPPN 4.2 R01 16.0 Total 100
(15) TABLE-US-00004 TABLE 4 structures and performance data for the light modulating device Haze in the Haze in the Device Cell Alignment light scattering transparent structure gap/μm layer state/% state/% FIG. 1 16 None 76.6 66.4 FIG. 1 20 None 78.9 68.9 FIG. 2 16 TN 67.8 27.8 FIG. 3 16 TN 61.6 24.5 FIG. 3 20 TN 65.3 26.7 FIG. 3 20 IPS 64.3 25.6
Example 1
(16) TABLE-US-00005 TABLE 5 formula of liquid crystal mixture Component Ratio/% NPP7PPN 25.0 2PPN 4.9 5PPN 14.0 5OPPN 10.8 6OPPN 5.1 3PP.sup.11PN 10.8 5HPPN 5.7 5PPPN 2.7 R01 16.0 NPPO5OPPN 5.0 Total 100
(17) TABLE-US-00006 TABLE 6 structures and performance data for the light modulating device Haze in the Haze in the Device Cell Alignment light scattering transparent structure gap/μm layer state/% state/% FIG. 1 16 None 88.8 3.3 FIG. 1 16 None 87.3 3.2
Example 2
(18) TABLE-US-00007 TABLE 7 formula of liquid crystal mixture Component Ratio/% NPP7PPN 28.0 2PPN 5.0 5PPN 14.6 5OPPN 11.2 6OPPN 5.3 3PP.sup.11PN 11.2 5HPPN 5.9 5PPPN 2.8 R01 16.0 Total 100
(19) TABLE-US-00008 TABLE 8 structures and performance data for the light modulating device Haze in the Haze in the Device Cell Alignment light scattering transparent structure gap/μm layer state/% state/% FIG. 1 16 None 89.0 5.2 FIG. 3 16 TN 86.0 1.9 FIG. 3 16 IPS 88.0 2.1 FIG. 1 20 None 91.0 5.5
Example 3
(20) TABLE-US-00009 TABLE 9 formula of liquid crystal mixture Component Ratio/% 2PPN 4.9 5PPN 14.0 5OPPN 10.8 6OPPN 5.1 3PP.sup.12PN 10.8 5HPPN 5.7 5PPPN 2.7 R01 16.0 NPP7PPN 30.0 Total 100
(21) TABLE-US-00010 TABLE 10 structures and performance data for the light modulating device Haze in the Haze in the Device Cell Alignment light scattering transparent structure gap/μm layer state/% state/% FIG. 1 16 None 89.0 1.9 FIG. 3 16 TN 87.0 1.5 FIG. 3 16 IPS 87.0 1.4 FIG. 1 20 None 90.5 2.0
Example 4
(22) TABLE-US-00011 TABLE 11 formula of liquid crystal mixture Component Ratio/% 2PPN 4.9 5PPN 14.0 5OPPN 10.8 6OPPN 5.1 3PP.sup.11PN 10.8 5HPPN 5.7 5PPPN 2.7 R01 18.0 NPP9PPN 10.0 NPP7PPN 18.0 Total 100
(23) TABLE-US-00012 TABLE 12 structures and performance data for the light modulating device Haze in the Haze in the Device Cell Alignment light scattering transparent structure gap/μm layer state/% state/% FIG. 1 16 None 90.5 1.8 FIG. 3 16 TN 88.2 1.7 FIG. 3 16 IPS 87.2 1.5 FIG. 1 20 None 91.3 2.1
Example 5
(24) TABLE-US-00013 TABLE 13 formula of liquid crystal mixture Component Ratio/% 2PPN 4.9 5PPN 14.0 5OPPN 10.8 6OPPN 5.1 3PP.sup.11PN 10.8 5HPPN 5.7 5PPPN 2.7 R01 12.0 NPP11PPN 5.0 NPP7PPN 18.0 NPP9PPN 11.0 Total 100
(25) TABLE-US-00014 TABLE 14 structures and performance data for the light modulating device Haze in the Haze in the Device Cell Alignment light scattering transparent structure gap/μm layer state/% state/% FIG. 1 16 None 89.2 4.5 FIG. 3 16 TN 86.5 2.4 FIG. 2 16 IPS 88.3 2.4 FIG. 1 20 None 90.2 4.6
Example 6
(26) TABLE-US-00015 TABLE 15 formula of liquid crystal mixture Component Ratio/% 2PPN 5.1 5PPN 14.5 5OPPN 11.2 6OPPN 5.3 3PP.sup.11PN 11.2 5HPPN 5.9 3PP.sup.23TPO2 2.8 R01 16.0 NPP11PPN 5.0 NPP7PPN 18.0 NPP9PPN 5.0 Total 100
(27) TABLE-US-00016 TABLE 16 structures and performance data for the light modulating device Haze in the Device Cell Alignment Haze in the light transparent structure gap/μm layer scattering state/% state/% FIG. 1 16 None 90.4 4.7 FIG. 3 16 TN 86.5 2.3 FIG. 3 16 IPS 87.3 2.5 FIG. 1 20 None 91.5 5.2
Example 7
(28) TABLE-US-00017 TABLE 17 formula of liquid crystal mixture Component Ratio/% 2PPN 5.1 5PPN 14.5 5OPPN 11.2 6OPPN 5.3 3PP.sup.11PN 11.2 2PP.sup.11P4 2.8 5HPPN 3.1 5PPPN 2.8 R01 16.0 NPP11PPN 5.0 NPP7PPN 18.0 NPP9PPN 5.0 Total 100
(29) TABLE-US-00018 TABLE 18 structures and performance data for the light modulating device Haze in the Device Cell Alignment Haze in the light transparent structure gap/μm layer scattering state/% state/% FIG. 1 16 None 89.5 4.2 FIG. 3 16 TN 86.7 2.3 FIG. 3 16 IPS 87.2 2.1 FIG. 1 20 None 90.8 5.3
Example 8
(30) TABLE-US-00019 TABLE 19 formula of liquid crystal mixture Component Ratio/% 2PPN 5.1 5PPN 14.5 5OPPN 11.2 6OPPN 5.3 3PP.sup.11PN 11.2 5HPPN 2.8 2PP.sup.23P4 3.1 5PPPN 2.8 R01 16.0 NPP11PPN 5.0 NPP7PPN 18.0 NPP9PPN 5.0 Total 100
(31) TABLE-US-00020 TABLE 20 structures and performance data for the light modulating device Haze in the Device Cell Alignment Haze in the light transparent structure gap/μm layer scattering state/% state/% FIG. 1 16 None 90.5 4.8 FIG. 3 16 TN 88.5 2.0 FIG. 3 16 IPS 87.9 1.9 FIG. 1 20 None 91.6 4.5
Example 9
(32) TABLE-US-00021 TABLE 21 formula of liquid crystal mixture Component Ratio/% NPP7PPN 25.0 L05 0.1 R01 19.0 NPPO5OPPN 4.9 5PPN 13.3 3PP.sup.11PN 10.2 6OPPN 4.8 2PPN 4.5 5OPPN 10.2 5HPPN 5.4 5PPPN 2.6 Total 100
(33) TABLE-US-00022 TABLE 22 structures and performance data for the light modulating device Haze in the Device Cell Alignment Haze in the light transparent structure gap/μm layer scattering state/% state/% FIG. 1 16 None 86.7 2.5
Example 10
(34) TABLE-US-00023 TABLE 23 formula of liquid crystal mixture Component Ratio/% NPP7PPN 25.0 R01 13.0 2PPN 2.8 4PPN 0.3 3OPPN 1.2 5PPN 24.2 5OPPN 9.9 7PPN 3.1 6OPPN 2.5 8OPPN 3.1 3PP.sup.11PN 6.8 5HPPN 5.0 5PPPN 3.1 Total 100
(35) TABLE-US-00024 TABLE 24 structures and performance data for the light modulating device Haze in the Device Cell Alignment Haze in the light transparent structure gap/μm layer scattering state/% state/% FIG. 1 16 None 85.7 9.1 FIG. 3 16 IPS 80.2 2.3
Example 11
(36) TABLE-US-00025 TABLE 25 formula of liquid crystal mixture Component Ratio/% NPP7PPN 27.0 R01 13.0 2PPN 2.7 4PPN 0.3 3OPPN 1.2 5PPN 23.4 5OPPN 9.6 7PPN 3.0 6OPPN 2.4 8OPPN 3.0 3PP.sup.11PN 6.6 5HPPN 4.8 5PPPN 3.0 Total 100
(37) TABLE-US-00026 TABLE 26 structures and performance data for the light modulating device Haze in the Device Cell Alignment Haze in the light transparent structure gap/μm layer scattering state/% state/% FIG. 1 16 None 88.9 11.8 FIG. 3 16 IPS 81.7 2.9
Example 12
(38) TABLE-US-00027 TABLE 27 formula of liquid crystal mixture Component Ratio/% NPP7PPN 34.0 R01 16.0 5PPN 13.0 3PP.sup.11PN 10.0 6OPPN 4.7 2PPN 4.5 5OPPN 10.0 5HPPN 5.3 5PPPN 2.5 Total 100
(39) TABLE-US-00028 TABLE 28 structures and performance data for the light modulating device Haze in the Device Cell Alignment Haze in the light transparent structure gap/μm layer scattering state/% state/% FIG. 1 16 None 90.7 6.2
Example 13
(40) TABLE-US-00029 TABLE 29 formula of liquid crystal mixture Component Ratio/% NPP7PPN 20.0 R01 16.0 5PPN 25.0 3PP.sup.11PN 5.0 6OPPN 3.0 2PPN 3.0 5OPPN 3.0 NPP5PPN 5.0 NPP9PPN 20.0 Total 100
(41) TABLE-US-00030 TABLE 30 structures and performance data for the light modulating device Haze in the Device Cell Alignment Haze in the light transparent structure gap/μm layer scattering state/% state/% FIG. 1 16 None 92.4 14.2
Example 14
(42) TABLE-US-00031 TABLE 31 formula of liquid crystal mixture Component Ratio/% 2PPN 4.9 5PPN 14.0 5OPPN 10.8 6OPPN 5.1 3PP.sup.11PN 10.8 5HPPN 5.7 5PPPN 2.7 R01 12.0 NPP.sup.127P.sup.11PN 5.0 NPP7PPN 18.0 NPP9PPN 11.0 Total 100
(43) TABLE-US-00032 TABLE 32 structures and performance data for the light modulating device Haze in the Device Cell Alignment Haze in the light transparent structure gap/μm layer scattering state/% state/% FIG. 1 16 None 90.5 5.5 FIG. 3 16 TN 87.3 4.4 FIG. 2 16 IPS 89.6 3.4 FIG. 1 20 None 91.4 4.6
Example 15
(44) TABLE-US-00033 TABLE 33 formula of liquid crystal mixture Component Ratio/% 2PPN 4.9 5PPN 14.0 5OPPN 10.8 6OPPN 5.1 3PP.sup.11PN 10.8 5HPPN 5.7 5PPPN 2.7 R01 12.0 NP.sup.22P7PP.sup.21N 5.0 NPP7PPN 18.0 NPP9PPN 11.0 Total 100
(45) TABLE-US-00034 TABLE 34 structures and performance data for the light modulating device Haze in the Device Cell Alignment Haze in the light transparent structure gap/μm layer scattering state/% state/% FIG. 1 16 None 90.6 5.5 FIG. 3 16 TN 87.5 3.4 FIG. 2 16 IPS 89.4 4.4 FIG. 1 20 None 91.7 5.6
Example 16
(46) TABLE-US-00035 TABLE 35 formula of liquid crystal mixture Component Ratio/% NPP7PPN 10.0 R01 15.9 5PPN 20.1 3PP.sup.11PN 10.7 6OPPN 5.1 2PPN 7.1 5OPPN 6.0 5HPPN 3.2 5PPPN 1.5 NPP5PPN 3.0 NPP9PPN 16.9 PM001 0.5 Total 100
(47) Where, after preparation, the light modulating device was placed under a UV light source (365 nm, 10 mw/cm.sup.2) for 60 seconds to polymerize the polymerizable monomer PM001.
(48) TABLE-US-00036 TABLE 36 structures and performance data for the light modulating device Haze in the Device Cell Alignment Haze in the light transparent structure gap/μm layer scattering state/% state/% FIG. 1 16 None 86.2 4.5 FIG. 3 16 TN 87.5 1.6
Example 17
(49) TABLE-US-00037 TABLE 37 formula of liquid crystal mixture Component Ratio/% NPP7PPN 10.0 R01 15.9 5PPN 20.0 3PP.sup.11PN 10.7 6OPPN 5.1 2PPN 7.0 5OPPN 6.0 5HPPN 3.3 5PPPN 1.5 NPP5PPN 3.0 NPP9PPN 16.9 NOA65 0.5 Photo initiator 184 0.1 Total 100
(50) Where, after preparation, the light modulating device was placed under a UV light source (365 nm, 10 mw/cm.sup.2) for 60 seconds to polymerize the polymerizable monomer inside NOA65.
(51) TABLE-US-00038 TABLE 38 structures and performance data for the light modulating device Haze in the Device Cell Alignment Haze in the light transparent structure gap/μm layer scattering state/% state/% FIG. 1 16 None 87.8 1.9 FIG. 3 16 TN 87.1 1.4
Example 18
(52) TABLE-US-00039 TABLE 39 formula of liquid crystal mixture Component Ratio/% NPP7PPN 15.0 R01 16.0 5PPN 14.0 3PP.sup.11PN 10.8 6OPPN 5.1 2PPN 4.9 5OPPN 5.4 5HPPN 5.7 NPP9PPN 15.0 2P.sup.21TPP3 2.7 4P.sup.21TPP3 5.4 Total 100
(53) TABLE-US-00040 TABLE 40 structures and performance data for the light modulating device Haze in the Device Cell Alignment Haze in the light transparent structure gap/μm layer scattering state/% state/% FIG. 1 16 None 88.7 3.7
Example 19
(54) TABLE-US-00041 TABLE 41 formula of liquid crystal mixture Component Ratio/% NPP7PPN 30.0 R01 16.0 5PPN 13.8 3PP.sup.11PN 10.8 6OPPN 5.1 2PPN 4.9 5OPPN 10.8 5HPPN 5.9 5PPPN 2.7 Total 100
(55) TABLE-US-00042 TABLE 42 structures and performance data for the light modulating device Haze in the Device Cell Alignment Haze in the light transparent structure gap/μm layer scattering state/% state/% FIG. 1 16 None 87.8 1.4 FIG. 1 15 None 86.9 1.8 FIG. 1 20 None 88.1 3.1 FIG. 3 20 STN 90.2 1.6 FIG. 1 50 None 94.5 10.8 FIG. 3 50 STN 92.5 5.2
Example 20
(56) TABLE-US-00043 TABLE 43 formula of liquid crystal mixture Component Ratio/% 2PPN 4.9 5PPN 14.0 5OPPN 10.8 6OPPN 5.1 3PP.sup.11PN 10.8 5HPPN 5.7 5PPPN 2.7 R01 12.0 NP.sup.22P11PP.sup.21N 5.0 NPP7PPN 13.0 NPP9PPN 11.0 4PP.sup.117P.sup.12PN 5.0 Total 100
(57) TABLE-US-00044 TABLE 44 structures and performance data for the light modulating device Haze in the Device Cell Alignment Haze in the light transparent structure gap/μm layer scattering state/% state/% FIG. 1 16 None 90.7 5.4 FIG. 3 16 TN 87.2 3.4 FIG. 2 16 IPS 89.4 3.8 FIG. 1 20 None 91.2 5.2
(58) From the above examples and comparative example, it is demonstrated that the light modulating device containing the liquid crystal mixture of the present invention has a significantly low haze in the transparent state and an ultra-high haze in the light scattering state, thereby providing high light transmittance while keeping sufficient privacy and isolation.
(59) In addition, for the purpose of concise illustration, the drawings herein are described in terms of a substantially planar form. However, it should be understood by those skilled in the art that the rearview mirror (and all of its functional layers) of the present invention may also include concave and convex curved surfaces, such as cylinders, spheres, ellipsoids, parabolas, or their combination. In addition, it will be appreciated by those skilled in the art that the rearview mirror of the present invention may also be applied to a combined rearview mirror system which has two or more different mirrors with different reflection directions or curvature characteristics.
(60) While several particular exemplary embodiments have been described above in detail, the disclosed embodiments are considered illustrative rather than limiting. Those skilled in the art will readily realize that alternatives, modifications, variations, improvements, and substantial equivalents are possible without substantially departing from the novelty spirits or scope of the present disclosure. Thus, all such alternatives, modifications, variations, improvements, and substantial equivalents are intended to be embraced within the scope of the present disclosure as defined by the appended claims.
INDUSTRIAL APPLICABILITY
(61) The liquid crystal mixture of the present invention can be applied to the field of liquid crystal.