TW201042014A - Reflective liquid crystal material formulation and reflective bistable display using the same - Google Patents

Abstract

The invention discloses a reflective liquid crystal material formulation, wherein a liquid crystal component of high dielectric anisotropy is employed to lower the driving voltage. By modulating the addition ratio of the high dielectric anisotropy components, reflective liquid crystal compositions of different colors can be driven by a single driving voltage. The invention also provides a reflective bistable display using the above formulation.

Description

201042014 VI. INSTRUCTIONS: TECHNICAL FIELD OF THE INVENTION The present invention relates to liquid crystal materials and their applications, and in particular to a reflective liquid crystal material formulation which can be applied to monochrome, multi-color, or full color. Reflective bistable liquid crystal display. I prior art] In liquid crystal display (LCD), there are quite a few different types of 0, and the most common ones are TN (twisted nematic 'twisted nematic) and STN (super twisted nematic). , super-torsional nematic liquid crystal), ferroelectric liquid crystal FLC (ferroelectric), cholesteric liquid crystal and other different types. Cholesteric liquid crystal, also known as chiral nematic liquid crystal material, consists of a simple nematic liquid crystal and a special chiral dopant, which is originally arranged in a nematic arrangement. The liquid crystal material is affected by the palmitic additive, resulting in a stronger twist than TN or ST^Q. The source can save the information 5; on the other hand, it has the characteristics of reflecting the external light source, so that the liquid crystal material itself has several different states, including the vertical direction of the parallel electric field of the liquid crystal molecules under the electric field ( 〇 〇 〇 〇 ) ) 以及 以及 以及 以及 以及 以及 以及 以及 以及 以及 以及 以及 以及 以及 以及 以及 以及 以及 以及 以及 以及 以及 以及 以及 以及 以及 以及 以及 以及 以及 以及 以及 以及 以及 以及 以及 胆固醇 胆固醇 胆固醇 胆固醇 胆固醇 胆固醇 胆固醇 胆固醇 胆固醇 胆固醇Both steady states can be stably existed without an applied electric field. The planar or dark state (planar/f0cal conic) has no backlight and polarized light except the switching process. 3 201042014 Energy saving, spontaneous reflected light characteristics can be reflected for different wavelengths of light, so color filters are not required to achieve color display requirements. For more detailed description of the driving and optical characteristics of cholesteric liquid crystals, please refer to the United States. Patent No. US 5,251,048 or US 5,695,682. The pitch P of the cholesteric liquid crystal material is determined by the concentration of the palmitic additive (concentration, c) and its helical twisting force (helical tw Isting power, HTP) determines the following relationship: p=l/(HTP*C) Q Since the wavelength of the reflection of the cholesteric liquid crystal is determined by the pitch, the pitch of the formulation is again subjected to the helical torsion of the palm additive used in the formulation. And concentration control. Therefore, by adjusting the concentration of the palmitic additive, a cholesterol liquid crystal material that reflects different colors (wavelengths) can be obtained. The higher the concentration of the palmitic additive, the smaller the reflection wavelength is, the shorter the reflection wavelength is. (Bluish blue). However, the higher the concentration of the 'palmative additive', the higher the driving voltage required. Therefore, the cholesteric liquid crystal formulation will have different driving voltages. The reflectance/driving voltage diagram of Figure 1 (R- Νcurve), different color cholesteric liquid crystal materials (in the case of rgb), the driving voltages VR, vG and vB are different (the solid line in the figure is the planar state, the dotted line is the focal conic state). In the full color display, three sets of driving voltages are required to drive the red (r), green (G), and blue (B) cholesteric liquid crystal materials respectively. From the above, how to reduce the driving voltage of the cholesteric liquid crystal material Further, if the cholesteric liquid crystal material of different reflection wavelengths can be driven by a single set of driving voltages, the driving circuit will be interposed. 201042014 SUMMARY OF THE INVENTION The present invention provides a reflective liquid crystal material formulation, including the following At least two liquid crystal compositions in (A), (B), and (C): (A) a first liquid crystal composition exhibiting a first reflection wavelength, comprising: 100 parts by weight of the first liquid crystal host, comprising: 100% of the first monomer And 3-10 parts by weight of the first palm additive; (B) the second liquid crystal composition exhibiting a second reflection wavelength, comprising:

100 parts by weight of the second liquid crystal host, comprising: 60-80% of the first monomer; 20-40% of the second monomer; and 3-10 parts by weight of the second palm additive. (C) a third liquid crystal composition exhibiting a third reflection wavelength comprising: 100 parts by weight of the third liquid crystal host, comprising: 10-60% of the first monomer; 40-90% of the second monomer; and 3-10 parts by weight a third palm additive; wherein the first monomer comprises at least the monomer of formula (I):

R1—l-A~Z1+-|-B-hz2———CN

Jn[ Jm (I) The second monomer contains at least the monomer of formula (III):

(ΠΙ) Each R1 is independently selected from a hydrogen atom, a linear chain of 1-15 carbons 5 201042014 or a branch or class, or (4) 2 x ^ ^ ^ nx 'alkanes or ones of alkene The above hydrogen atom may be substituted by CH i, ancient A, and 'CF3, one or more of alkane or alkene, ο-, yl ('〇-), thio (4), shouting (( =〇)_) or vinegar - Cho)-); each Α and Β are independent of each other, selected from the reverse '1,4-hexyl-alkylcyclohexane or benzene ring (1) , 4-phenylene) 'One or more of the ring structures may be substituted with an oxygen atom ^, and one or more =CH- may be substituted with an N atom, and the hydrogen atom on the ring may be halogen or CN Substituted by a CF3 substituent; each, Zl ❹

Independent of ^ is selected from a single bond, an ether group (-〇-), a thio group (·&), a _ group (-C(-O)·), an ester group ({(=〇)), 〇c(=〇)_), _cF2〇_, _〇CF2-, -CH2CH2-, _CF2CF2-, cis or trans _c=c_ double bond, or -c彡 bond, η and m knife are An integer of n + m between 1 and 3; and 'L is a halogen atom or a fluorine atom. The present invention further provides a reflective bistable liquid crystal display comprising: a first electrode layer; a second electrode layer; the aforementioned reflective liquid crystal of the present invention

The material formulation is disposed between the first electrode layer and the second electrode layer, wherein the I-liquid crystal compositions are isolated from each other, and the driving electric power of any two liquid crystals is less than 4V. In order to make the present invention and other objects, features, and advantages of the present invention more comprehensible, the preferred embodiments are described below, and the accompanying drawings are illustrated as follows: [Embodiment] The present invention provides A low-drive voltage reflective liquid crystal formulation in which different color liquid crystal materials are adjusted, and a high dielectric anisotropy liquid crystal 201042014 material is used to lower the driving voltage, and different colors are controlled by adjusting the skew ratio of different dielectric anisotropy materials. The driving voltage of the cholesteric liquid crystal formulation tends to be the same, as shown in Fig. 2. The cholesteric liquid crystal material of the present invention has a reflection wavelength which falls within a range of visible light (380 nm - 800 nm) and can be applied to a monochrome or color display material application. The pitch of the cholesteric liquid crystal material of the present invention is usually less than lum, which is about 〇.2~〇.5um. The cholesteric liquid crystal material used in the present invention will be described in detail below. ο β * The liquid crystal materials used in the invention can be mainly divided into two groups, namely, a first monomer having a relatively low dielectric anisotropy (Group I), and a second single having a relatively high dielectric anisotropy. Body (Group II). In one embodiment, the dielectric anisotropy of the first monomer is, for example, less than 2 Å, and the dielectric anisotropy of the second monomer is, for example, greater than or equal to 20. In another embodiment, the dielectric anisotropy of the first monomer is, for example, less than 15, and the dielectric anisotropy of the second monomer is, for example, greater than or equal to 15. In other words, as long as the two monomer groups have relatively high dielectric anisotropy. 0 The first monomer comprises at least the monomer of formula (1), and optionally comprises a monomer of formula (II):

Wherein R1 is selected from a hydrogen atom, a linear or branched alkane or an alkene of 1 to 15 carbons, and one or more hydrogen atoms of an alkane or an alkene may be substituted with a halogen 7 201042014 or a substitution of CN and CF3. One or more CH2 groups of a base, alkane or alkene may be substituted with a bond group (-0-), a thio group (-S-), a thiol group (-C(=0)-) or a vine group (-0). (=〇)〇----0C(=0)-); Each A and B are independent of each other and are selected from trans-l, 4-cyclohexylene or Benzene ring (1,4-phenylene), one or more of -CH2- may be substituted by an oxygen atom or -NH-, one or more =CH- may be substituted by an N atom, and any hydrogen atom on the ring may be substituted. Substituted by halogen or CN, 0?3 substituent; each Z1 and Z2 are independently selected from a single bond, an ether group (-〇-), a thio group (-S-), a thiol group (-C ( =0)-), vinegar (-(^(=0)0-, -0C(=0)-), -CF20-, -OCF2-, -CH2CH2_, -CF2CF2-, cis or trans-c =c-double bond, or -c=c- triple bond; and η and m are each an integer of 0-3, and n+m is between 1 and 3. The first monomer may further comprise the following formula (II) as needed Monomer:

R2 (II) In the formula (11), 111, human,; 6, 21, 22, 11, 111 are as defined above, and R2 is selected from a hydrogen atom, a linear or branched alkane of 1 to 15 carbons. One or more hydrogen atoms of the class or alkene, alkane or alkene may be substituted with a halogen, a CF3 substituent, and one or more CH 2 of the alkane or alkene may be substituted with an ether group (-0-), sulfur The group (-S-), 3 is the same group (-C(=0)-) or the group (-C(=0)0-, _oc(=o)-). 8 201042014 The structure of formula (II) replaces the CN group at the end of the molecule of formula (I) with R2, and has a weaker dielectric anisotropy than formula (1). In general, the dielectric anisotropy of the monomer of the formula (1) is in the range of from 5 to 20, and the dielectric anisotropy of the monomer of the formula (II) is in the range of from -5 to +5. The monomer of formula (II) is mainly used in the liquid crystal formulation to adjust the temperature range of the liquid crystal phase and reduce the overall viscosity of the liquid crystal formulation, and may be added to the first monomer as needed, or not added at all.

The second monomer comprises at least a monomer of formula (III), and optionally comprises a monomer of formula (IV): R1

(III) R1 is selected from a hydrogen atom, a linear or branched alkane or an alkene of 1 to 15 carbons, and one or more hydrogen atoms of the alkane or alkene may be substituted with a halogen or a substitution of CN or CF3. One or more 012 of a base, alkane or alkene may be substituted with an ether group (-0-), a thio group (-S-), a keto group (-C(=0)-) or an ester group (-C). (=0)0-, ❹-oc(=o)-); Each A and B are each independently selected from a trans-l, 4-cyclohexylene or Benzene ring (1,4-phenylene), one or more of -CH2- may be substituted by an oxygen atom or -NH-, one or more =CH- may be substituted by an N atom, and any hydrogen atom on the ring may be substituted. Substituted by a halogen or a CN, CF3 substituent; each Z1 and Z2 are independently selected from a single bond, an ether group (-0-), a thio group (-S-), a keto group (-C (=0) )-), ester group (-c(=o)o-, . -0C(=0)-), -CF20- '-OCF2- '-CH2CH2----CF2CF2-, cis or trans- Oc- 201042014 double bond, or -oc- triple bond; η and m are each an integer of 0_3, and n+m is between 1 and 3; and, L is a germanium atom or a fluorine atom. The molecular structure of the liquid crystal material of the formula (I) is one or two F atoms added to the head benzene ring of the formula (I), and has a high dielectric anisotropy with respect to the formula (I). In general, the dielectric anisotropy of the monomer of the formula (III) is between about 15 and 50, which can improve the dielectric anisotropy of the liquid crystal formulation and can effectively lower the driving voltage of the liquid crystal.

The second monomer may further comprise a monomer of the following formula (IV) as needed:

Wherein 1^1, 八, 八, 乙, 1, 22, 11, 111 are as defined above, and are also a fluorine atom, CF3 or OCA, and L1 and L2 are each independently a hydrogen atom or a fluorine atom.

The molecular structure of the liquid crystal material of the formula (IV) is such that the CN substituent on the head of the formula (ΙΠ) is changed to an X substituent such as F atom, CR or 〇CF3. The dielectric anisotropy of the material of formula (IV) is relatively lower than the formula (ΙΠ), usually in the range of 5 to 2 Å. The monomer of formula (IV) is less used in cholesteric liquid crystal materials, but some special requirements can be used to adjust some of the properties of the formulation through the use of this type of liquid crystal material, for example, to adjust the overall viscosity of the formulation and improve the driving time. The liquid crystal composition of the present invention includes palmitic additives in addition to the above liquid crystal monomers, and several palmitic additives are listed below, but the present invention is not limited thereto. 'Formula(v)~(VIII) are four commercially available palmitic additives respectively. 201042014 Chemical Structure:

/ (VIII) Other palmitic additives that may be used include US6217792; V. Vill, F. Fischer, and J. Thiem, Zeitschrift Fur Naturfoschung A., Journal of Physical Science, 43a(12), 1119-1125 (1988) The palmitic additive disclosed in GB2328207; US7052743; US7150900B2, such as formula (IX) to formula (XI), mostly has a larger helical twisting force than the foregoing.

11 201042014

Wherein each R is independently selected from a halogen atom, a linear or branched alkane or an alkene of 1 to 15 carbons, and one or more hydrogen atoms of the alkane or alkene may be substituted with a halogen or a CN. One or more of a CF3 substituent, an alkane or an alkene (: 112 may be substituted with an ether group (-0-), a thio group (-S-), a keto group (-C(=0>-) or Ester group (-c(=o)o_, _oc(=o>_); Α Each Α and Β are independent, and are trans-l, 4-cyclohexylene Or a phenyl ring (l,4-phenylene), one or more of -CH2- may be substituted by an oxygen atom or -NH- '. One or more =CH- may be substituted as: N atom, any hydrogen on the ring Atoms may also be substituted by halogen or CN, CF3 substituents; each Z is independently, which is a single bond structure, an ether group (-0-), a thio group (-S-), a keto group (-c (=o) )_), ester group (_c(=o)o-, -0C(=0)-), -CF20-, -OCF2, -CH2CH2-, -cf2*cf2-, cis or trans-c= C-double bond, or -oc- triple bond structure; 12 201042014 Each η is independently, an integer of 1 or 2. The reflective liquid crystal material formulation of the present invention uses a second monomer of high dielectric anisotropy. The driving voltage is lowered, and the combination of the first monomer and the second monomer in different ratios can drive a plurality of liquid crystal combinations of different colors by using a single driving voltage. Hereinafter, a full color liquid crystal display is taken as an example to illustrate the composition of the present invention. The full color reflective liquid crystal material formulation of the present invention comprises: 0 (Α) a first liquid crystal composition exhibiting a first reflection wavelength (such as red light), comprising: 100 parts by weight of the first liquid crystal body, comprising: 100% first Monomer; 3-10 parts by weight of the first palm additive. (Β) The second liquid crystal composition exhibits a second reflection wavelength (such as green light), comprising: 100 parts by weight of the second liquid crystal body, comprising: 60-80% a monomer; 20-40% of the second monomer; and ❹ 3-10 parts by weight of the second palm additive. (C) a third liquid crystal composition exhibiting a third reflection wavelength (such as blue light), including: 100 parts by weight The three liquid crystal host comprises: 10-60% of the first monomer; and 40-90% of the second monomer; 3-10 parts by weight of the third palmitic additive. As can be seen from Fig. 1, the driving voltage VbSVgSVr. The invention In order to lower the driving voltage, in the second (green) liquid crystal body , adding a proportion of 13 201042014 (20-40%) of high dielectric anisotropy second monomer, and adding a higher proportion (40-90%) of high dielectric difference in the third (blue) liquid crystal body The second monomer is so that the cholesteric liquid crystal materials of the respective colors have the same or similar driving voltage. In one embodiment, the dielectric anisotropy of the first (red) liquid crystal body is less than 20 (for example, about 15) 〜18), therefore, the addition ratio of the second monomer is preferably such that the dielectric anisotropy of the first (green) liquid crystal host is controlled to be between about 2 〇 25 and 25, and the second (blue) liquid crystal body is made The dielectric anisotropy is controlled between about 30 and 45. In this way, the driving voltage difference between the liquid crystal materials of two or more colors can be less than 4V. More preferably, the driving voltage difference is less than 3V, even Less than IV. It should be noted that the first monomer contained in the liquid crystal compositions (a), (B), and (C) may be the same as or different from the first monomer, and the first, second, and second palm additives may be used. The same or different materials selected from the above formula (V) to formula (XI), or other known palmitic additives. Although the above formula is described by taking a full-color liquid crystal material formulation as an example, it should be understood that the present invention can also select only two kinds of liquid crystal materials. t 'liquid ί 成 (A) and (8), (4) and (C), or (8) and (C) are useful as color liquids, as long as the reflection wavelength difference between any two of the two components is greater than 5Gnm. Alternatively, it can also be applied to a single day (day of black and white contrast) liquid day and day display. The following will further explain the above-mentioned liquid crystal material applied to the implementation of the display, comprising at least two electrodes, disposed in the two electrode layers 'and any two liquid crystals constitute the reflective bistable liquid crystal display layer of the present invention' and the front shape Between the formulations of the reflective dissimilar crystal materials, the driving voltage difference between each liquid crystal composition is less than 4V. 14 201042014 In one embodiment, the reflective liquid crystal material formulation of the present invention is applied to a multi-layer stacked color display device as shown in FIG. 3, which comprises a three-layer stacked light modulating layer. 10. Π0, 130, respectively, comprising three kinds of cholesteric liquid crystal compositions of R, G, and B, for example, the liquid crystal compositions (A), (B), and (C) described above. Each of the light regulating layers is disposed between the two transparent electrodes 101 to control the cholesteric liquid crystal in the light regulating layer to be a Planar state or a Focal Conic State. The transparent electrode 101 is, for example, indium tin oxide (ITO), indium zinc oxide (IZO) or the like. The composition of the present invention can be directly coated on a transparent electrode as a light-regulating layer 'or a mixed solution with a polymer monomer, and then coated, and the monomer is polymerized by heat or illumination, with the polymerization process. The solubility between the monomer and the liquid crystal is reduced to cause phase separation. Finally, the liquid crystal is dispersed in the polymer in the form of droplets, and becomes a polymer dispersed liquid crystal (PDChLC). It is a hard substrate such as glass or quartz, but can also be a flexible substrate for application to a flexible display device. Polymer materials that can be used as flexible substrates include: polyethylene naphthalate (PEN; polyethylene naphthalate), polyethylene terephthalate (pET; polyethylene terephthalate), and polyamide. , polymethylmethacrylate, polycarbonate, p〇iyurethane, and the like. A light absorbing layer 500 is further disposed under the substrate 1 。. In another embodiment, the reflective liquid crystal material formulation of the present invention is intended to be used in a single layer color display, as shown in Figure 4, which includes at least one substrate 200 having a lower electrode layer 201. The lower electrode layer 201 has an isolation structure formed by a spacer 202 (for example, a polymer) on 201042014. The cholesteric liquid crystal compositions 210, 220, and 230 of the present invention, R, G, and B, can be applied to the spacer structure constituted by the spacer by inkjet or vacuum injection. An upper electrode layer 3〇 and an upper substrate are further disposed on the spacer 202. Similarly, a light absorbing layer 5 is also disposed under the lower substrate 200. In still another embodiment, the reflective liquid crystal material formulation of the present invention is applied to a monochrome (black and white contrast) display, as shown in FIG. 5, the device includes upper and lower substrates 200, 300, and a layer of polymer dispersed cholesteric liquid crystal. Q 400 is disposed between the upper electrode layer 301 and the lower electrode layer 201. A light absorbing layer 500 is disposed under the lower substrate 200. In the polymer-dispersed cholesteric liquid crystal 400, the cholesteric liquid crystals 420R, 420G, and 420B containing the three colors of R, G, and B are uniformly dispersed in a polymer matrix 410 such as an acrylic resin or an epoxy resin. Three kinds of cholesteric liquid crystals 420R, 420G, and 420B can be simultaneously operated by generating a voltage difference of one set by the upper and lower electrode layers, so that a black-and-white contrast display device can be achieved. Although the above three reflective bistable liquid crystal display devices are listed above, the application of the present invention is not limited thereto. For the fabrication of the reflective bistable liquid crystal display, reference may be made to US Pat. No. 7,382,424, US Pat. No. 7,119,859, US Pat. No. 6,570,633, US Pat. , US20060176257, US20060119782. The reflective bistable liquid crystal display of the invention can be applied to various electronic devices, such as mobile phones, digital cameras, personal data assistants (PDAs), notebook computers, desktop computers, televisions, car displays, or portable devices. DVD player, etc. In order to further explain the embodiments of the present invention, the following examples of implementation 16 201042014 are listed. Unless otherwise stated, the %s described below are all % by weight. [Preparation Example] The formulations mentioned in the examples and the comparative examples were respectively: 1) BL087, purchased from Merck GmbH, having a dielectric anisotropy of about 17. 2) The base formula A of the first monomer, selected from the materials of formula (I) and formula (II), the composition of which is as follows: chemical structure % chemical structure% 12.6 10.0 31.9 6.2 21.8 C3H7~~<^^_OC2H5 7.2 ^Η,-ΟΟ-^ON 10.3 〇3) The base formula X of the second monomer, selected from the materials of formula (III), the composition of which is as follows: Chemical structure % Chemical structure % CsHr^^0^^CN 40 40 C3HK>^^〇^^cn 20 17 201042014 4) The base formula Y of the second monomer, selected from the materials of formula (III), whose composition is as follows: Chemical structure % —_ Chemistry% 30 10 20 ___ .. - c^K>〇^^cN 10 30

The palmitic additive uses a palmitic additive such as the structure of formula (IX), and its chemical structure is as follows:

The nematic liquid crystal material and the cholesteric liquid crystal material are prepared obliquely, and all the components are mixed according to the proportion of the weight, and the mixture is heated to make the formula material reach the temperature (Tc), and the temperature is obtained after the temperature is lowered. Its various photoelectric quality tests use LCAS (LC-Vision products, measuring dielectric anisotropy), UV-Vis spectrometer (measuring material reflection spectrum) and DMS-803 (Autroxiic i^elchers) according to different properties. The company's products measure the reflectance spectrum of liquid crystal panels and the photoelectric properties such as RV curve. 18 201042014 [Comparative Example 1] The formulation of Comparative Example 1 was formulated using the base formulation A of the first monomer and the palmitic additive (Z) to obtain a set of colored cholecylate liquid crystal formula combinations, which were prepared in proportion to cholesterol liquid crystal. The optical/electrical properties of the material are shown in the following table:

Imax A (%) z (%) Drive voltage (V) Red 670 95.6 4.4 23.2 Green 540 94.6 5.4 27.6 Blue 440 93.2 6.8 33.1

As can be seen from the above table, the driving voltage gradually increases with the addition of the palmitic additive, and the difference in the color liquid crystals of different colors is about 4 to 5 V, so three different driving voltages are required. Ο I Example 1] Example 1 uses the first monomer base formula A and the second monomer formula X to match, and also obtains a set of colored cholesteric liquid crystal formula combinations, and prepares the ratio of light/electricity of the cholesteric liquid crystal material. The nature is shown in the following table:

Xmax A (%) XC%) z (%) Drive voltage (V) Red 670 95.6 0 4.4 23.2 , Green 540 74.6 20.4 5.1 23.6 19 201042014 Blue 440 43.8 50.2 6.0 23.8 As can be seen from the above table, add a second order of different proportions After the formula x of the body, the driving voltage can be lowered to make the driving voltage difference of the red, blue and green cholesterol liquid crystal formulas <ιν, and only one set of driving voltages can simultaneously control the three colors. [Comparative Example 2] The formulation of Comparative Example 2 was prepared by using commercially available BL087 and palmitic 0 additive to obtain a set of colored cholesteric liquid crystal formula combinations, the ratio of which was prepared and the optical/electrical properties of the cholesteric liquid crystal material are as follows: Show: λτηαχ BL087 (%) ζ (%) Drive voltage red 650 95.5 4.5 22.8 Green 530 94.4 5.6 27.3 Blue 480 93.8 6.2 29.2 Ο The result of Comparative Example 2 is similar to Comparative Example 1, and the driving voltage gradually increases with the addition of the palm additive. Therefore, different color cholesteric liquid crystal formulations require different driving voltages. [Example 2] The formulation combination of Example 2 was matched with the commercially available BL087 and the second monomer formulation X, and a set of colored cholesteric liquid crystal formula combinations were also obtained, and the ratio of the light/electric properties of the cholesteric liquid crystal material was prepared. As shown in the following table: 20 201042014

Imax BL087 (%) X (%) Z (%) Drive voltage (V) Red 650 95.5 0 4.5 22.8 Green 530 64.5 30.4 5.1 22.7 Blue 460 38.7 55.7 5.6 22.4 The result of Example 2 is similar to that of Example 1, making red and blue The driving voltage difference of the green cholesteric liquid crystal formula is <1V, and only one set of driving voltages can be used to control three colors when it is the same as 0. [Example 3] The formulation combination of Example 3 was matched with the commercially available BL087 and the second monomer formulation Y to obtain another set of colored cholesteric liquid crystal formula combinations, and the ratio of the light/electricity of the cholesteric liquid crystal material was prepared. The nature is shown in the following table:

Xmax BL087 (%) Y(%) z (%) Drive voltage Red 650 95.5 0 4.5 22.8 Green 530 58.8 36.3 4.9 23.1 Blue 450 21.7 72.6 5.7 23.3

Similarly, Example 3 also obtained a red, blue, and green cholesterol liquid crystal formulation having a driving voltage difference <1. 21 201042014 I Example 4] Take 2 liquid crystal cells (each containing 2 transparent glass substrates and transparent electrodes), respectively injecting the red and blue liquid crystal materials in the formula combination example 3, and the independent spectra are respectively as shown in FIG. Show. After overlapping the two liquid crystal cells, the two liquid crystal cells are driven synchronously. The spectral changes of the following figures can be observed during the process of 2.5V to 30V. It is obvious that the different color cholester liquid crystal materials have the same operating voltage. While the invention has been described above in terms of several preferred embodiments, it is not intended to limit the invention, and any one of ordinary skill in the art can be made without departing from the spirit and scope of the invention. The scope of protection of the present invention is defined by the scope of the appended patent application.

22 201042014 - [Simplified Schematic] Figure 1 is a schematic diagram of the reflectivity/drive voltage of a conventional reflective liquid crystal material formulation. Fig. 2 is a view showing the reflectance/drive voltage of a reflective liquid crystal material oblique formulation according to an embodiment of the present invention. Figure 3-5 is a schematic cross-sectional view showing a reflective bistable liquid crystal display according to an embodiment of the present invention. Figure 6 is an independent light of red and blue liquid crystal materials in Example 3.

Fig. 7 is a spectrum diagram of the red and blue liquid crystal materials in the synchronous driving embodiment 3. [Description of main components] 100, 200, 300 to substrate 110, 120, 130 to optical control layer 101 to transparent electrode 201 to lower electrode layer 301 to upper electrode layer 210, 220, 230 to cholesteric liquid crystal composition of the present invention 202~ spacer 400~ polymer dispersed cholesterol liquid crystal 410~ polymer matrix 420R~ red cholesterol liquid crystal 420G~ green cholesterol liquid crystal* * 420B~ blue cholesterol liquid crystal 23 201042014 500~ light absorbing layer

〇 24

Claims (1)

201042014 VII. Patent application scope: h A reflective liquid crystal material formulation, including the following (A), (Β), (at least two liquid crystal compositions: (A) The first liquid crystal composition, exhibiting a first reflection wavelength, including: 100 parts by weight of the first liquid crystal host, comprising: 100% of the first monomer; and 3-10 parts by weight of the first palm additive; (B) the second liquid crystal composition exhibiting a second reflection wavelength, including ··· 100 parts by weight The second liquid crystal body comprises: 60-80% of the first monomer; 20-40% of the second monomer; and 3-10 parts by weight of the second palm additive. (C) The second liquid crystal composition exhibits a third reflection wavelength And comprising: 100 parts by weight of a third liquid crystal host comprising: 10-60% of the first monomer; 40-90% of the second monomer; and 3-10 parts by weight of the third palmitic additive; B-hz2 wherein the monomer has at least a monomer of the formula ω -CN (I) The second monomer comprises at least the monomer of formula (III): Each R1 is independently selected from the group consisting of (III) a wind atom, a straight chain of 1·1, 5 carbons, 25 201042014 or a branched chain or an alkene, one or more hydrogen atoms of an alkane or an alkene may be Substituted as dentate or CN, CF3 substituent, one or more CH2 of alkane or alkene may be substituted with an ether group, a thio group (_s_), a keto group (_c(=0)-) or an ester group (- C(=0)0-, ·〇〇(=0)-); Each A and B are independent of each other and are selected from the trans-1,4-hexane substituent (trans-1,4-cycl〇) Hexylene) or a benzene ring (1,4-plienylene), one or more of -CHr in the ring structure may be substituted with an oxygen atom or ΝΗ ' ' ' One or more of which may be substituted by a ruthenium atom, and any hydrogen atom on the ring may be halogenated Or 0 CN, CF3 substituents are substituted; each Z1 and Z2 are independent. They are selected from a single bond, an ether group (_〇_), a thio group (-S-), a keto group (-c (=0) )·), ester group (-C(=〇)〇-, -0C(=0>-), •CF20-, -OCF2-, -CH2CH2-, cis or trans _C=C· double bond , or -OC·three bonds; n and m are integers of 〇_3, respectively, jl n+m is between 1 and 3; and, L is a royal atom or a fluorine atom. 2. As claimed in the first item The reflective liquid crystal material is configured to have a dielectric anisotropy of the first liquid crystal body of less than 2 〇, and a dielectric anisotropy of the second liquid crystal body of about 20-25. The electrical anisotropy is about 30-45. 3. The reflective liquid crystal material formulation of claim 1, wherein the difference between the first wavelength, the second wavelength, and the third wavelength is greater than 50 nm. The reflective liquid crystal material formulation of claim 2, wherein the first reflection wavelength is red light, the second reflection wavelength is green light, and the third reflection wavelength is blue light. 26 201042014 5. The method of the reflective liquid crystal material according to the fourth aspect of the invention, comprising: (A) a first liquid crystal composition and (B) a second liquid crystal composition. 6. The reflective liquid crystal material according to claim 4 a formulation comprising (A) a first liquid crystal composition and (c) a third liquid crystal composition. 7. The reflective liquid crystal material formulation of claim 4, comprising (B) a second liquid crystal composition and (c) a third liquid crystal composition. 8. Reflective type as described in claim 4 a crystalline material formulation comprising (4) a first liquid crystal composition, (B) a second liquid crystal composition, and (C) a third liquid crystal composition. 9. The reflective liquid crystal material formulation according to the above-mentioned claim, wherein the first The liquid crystal composition (A), the second liquid crystal composition (B), and the third liquid crystal composition (C) are dispersed in a polymer. The reflective liquid crystal material formulation as claimed in any one of the preceding claims, wherein the first monomer further comprises a monomer of the formula (11): , R1, A, B, Z1, Z2, η, m are as defined above, and R2 is selected from a hydrogen atom, a linear or branched alkane or an alkene of M5 carbons, or an alkane or an alkene. The above hydrogen atom may be substituted with a halogen or a CF3 substituent, and one or more CH2 of the alkane or alkene may be substituted with an ether group (_〇_), a thio group (-S-), a _ group «(= =0)-) or ester group (_c(=〇)〇_, _〇c(=〇)_). U. The reflective liquid crystal material formulation according to any one of claims 1 to 9, wherein the second monomer further comprises a monomer of the formula (IV): 27 201042014 Wherein R1, A, B, Z1, Z2, η, m are as defined above, X is a fluorine atom, CF3 or OCF3, and L1 and L2 are each independently a hydrogen atom or a fluorine atom. 12. The reflective liquid crystal material formulation according to any one of claims 1-9, wherein the first, second, and third palm additives are independent of each other, and are selected from the following formulas (V) to (XI). ) Compound: 28 201042014 Each of them is a single bond structure (-C(=0)-), an ester group (-C(=0)0-, wherein each R is independent, and is selected from a hydrogen atom and a carbon. One or more hydrogen atoms of a chain or branched alkane or alkene, an alkane or an alkene may be substituted as a functional element or a CN, CF3 substituent, and one or more CH 2 of an alkane or an alkene may be substituted with an ether. Base (_〇), thio group (each), ketone group (fC(=〇>_) or ester group (-C〇=0)〇-, -〇c(=〇)_); each A and B is independent of each other, which is a trans 1,4-hexanediene substituent (trans_ i , 4_cycl〇hexylene) or a benzene ring O (M-Phenylene), and one or more of the ring structures may be substituted with an oxygen atom or -NH. - one or more of the above =CH- may be substituted by an N atom, and any hydrogen atom on the ring may also be substituted by a halogen or a CN, CF3 substituent; An integer of X2. -cf20- •ch2ch2-, -cf2cf2-, cis or trans-center c_ double-key, or #& three integer. The device 'includes: a key structure; each η is independent of 1 or 9 13. A reflective bistable liquid crystal displays a first electrode layer; 29 201042014 a second electrode layer; The reflective liquid crystal material according to any one of the preceding claims, disposed between the first electrode layer and the second electrode layer, wherein the liquid crystal compositions are isolated from each other, and the driving voltage difference of any two liquid crystal compositions is less than 4V. . 14. The reflective bistable liquid crystal display of claim 13, wherein the liquid crystal compositions are isolated from each other by spacers. 15. The reflective bistable liquid crystal Q display of claim 13, further comprising at least one third electrode layer disposed between the first electrode layer and the second electrode layer to isolate the Liquid crystal composition. 16. The reflective bistable liquid crystal display of claim 13, wherein the liquid crystal composition is dispersed in a polymer. 17. The reflective bistable liquid crystal display of claim 13, wherein the reflective bistable liquid crystal display is a black and white contrast display. 18. The reflective bistable liquid crystal display of claim 13, wherein the reflective bistable liquid crystal display is a color display. 19. The reflective bistable liquid crystal display of claim 13, wherein the reflective bistable liquid crystal display is a full color display. 30