TWI290166B - Liquid crystal compounds, liquid crystal compositions and liquid crystal device employing the same - Google Patents

Abstract

A liquid crystal compound, a liquid crystal composition and a liquid crystal device employing the same. The liquid crystal compound has a high birefringence, low visco-elastic, low melting point, high light stability, and wide phase transition temperature. Furthermore, the compound is highly dissolved with liquid crystal host and the liquid crystal composition with the compounds can get high reflectivity and wide reflective bands.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal additive, and more particularly to a liquid crystal additive having a high birefringence and a liquid crystal composition containing the liquid crystal additive. [Prior Art] In recent years, with the rapid development of flat display technology, in the improvement of the display, special attention has been paid to the demand for small size and light weight, among which liquid crystal display (LCD) has attracted the most attention. Widely used in mobile phones, PDAs, computers, desktop or portable computers, digital cameras, car navigation systems and other types of display products. However, the demand for liquid crystal flat panel displays, in addition to improvements in the process, the liquid crystal will affect the overall performance of the display, is the most critical raw material, playing a pivotal role in the liquid crystal display. Conventional transmissive liquid crystal displays, due to their large volume of backlights, result in large size and power consumption, which cannot be achieved for portable electronic products. In contrast, the reflective liquid crystal display uses ambient light as a light source, which can save power consumption, weight, thickness and cost of the backlight module. In addition, the reflective liquid crystal display can overcome the problem of insufficient brightness when the penetrating liquid crystal display is used outdoors, so it can be widely applied to various liquid crystal displays of medium and small size portable type, for example, such as an e-book ( E-books, e-magazines, tablets, personal digital assistants (PDAs), etc., will all be the focus of reflective LCD development. However, the reflectivity of a conventional reflective liquid crystal display is significantly less than that of an information medium such as a book or a newspaper, and the reflectivity is obviously insufficient (see Table 1), thereby improving the reflection of the reflective liquid crystal display. The rate is in line with the portable 0424-A20507TWF (N2); 02930002; phoelip 6 1290166 display market is an extremely important topic. Display ambient reflection brightness contrast existing reflective LCD 30% (green) 7:1 white paper 80% 12:1 newspaper 55% 6:1 STN-LCD 21% 10:1 TN-LCD 21% 15:1 Table 1 Lifting reflection type The most critical and effective method for the reflectivity of liquid crystal display devices lies in the development of liquid crystal materials. The reflective liquid crystal display panel performs light reflection using a Bragg reflection method, and the spectral width of the reflection is Δλ=Διι氺p, where Δη is the birefringence of the liquid crystal material, and P is the pitch of the liquid crystal material. (pitch), so Αλ is proportional to Δη. Referring to Fig. 1, a schematic diagram of the relative relationship between the birefringence Δη of the liquid crystal material and the reflection spectrum width Δλ is shown. As can be seen from Fig. 1, the larger the value of Δη, the larger the reflection spectrum width and the higher the brightness. However, it is currently known that mass-produced liquid crystal materials generally have a birefringence of not more than 0.2, so that the reflected brightness (reflectance) exhibited by them is only 30% (under perfect assumption, Αη=1 can obtain complete brightness). With reflection spectrum). Further, from the results of simulating the relationship between the birefringence An and the reflection spectrum width Δλ, it can be found that when Αη > 0.3, the reflection spectrum width can cover green light (500 nm to 610 nm), and if Αη2 0.6 is further Its reflection spectrum covers the entire visible light with a reflectivity of up to 50%. In summary, if a liquid crystal molecule having a high birefringence Α η gt; 0·3 can be developed, the overall performance of the reflective liquid crystal display device can be improved, and the reflection efficiency, contrast, and reflectable wavelength range can be greatly improved. 0424-A20507TWF(N2);02930002;phoelip 7 1290166 SUMMARY OF THE INVENTION In view of the above, in order to improve the reflectivity of a reflective liquid crystal display and increase the reflection spectrum width, the object of the present invention is to provide a novel liquid crystal having a special chemical structure design. The material has a large birefringence, low dot, low melting point, good photothermal stability, wide temperature range of liquid crystal phase change, and excellent solubility for liquid crystal (Nematic Host), which is very suitable as a reflection type. Liquid crystal additive for liquid crystal displays. Another object of the present invention is to provide a liquid crystal composition having such a high birefringence liquid crystal additive to enhance a conventional commercially available liquid crystal formulation by the birefringent liquid crystal additive (conventional for a twisted nematic (TN) liquid crystal display Double-refractive nematic (stn> liquid crystal display, color super twisted nematic (CSTN) liquid crystal display or thin film transistor (TFT)) liquid crystal display liquid crystal) birefringence and reflection spectrum width, and reduce liquid crystal combination Viscosity. Another object of the present invention is to provide a liquid crystal display comprising the high birefringence liquid crystal additive, such as a reflective SSCT display and a polymer dispersed (PDLC) liquid crystal display, so that the reflectance thereof is not less than 35%. In order to achieve the above object, the liquid crystal additive having high birefringence according to the present invention comprises an organic compound as shown in the formula (I).

Wherein R1 or R2 is hydrogen, fluorine or an alkyl group having 1 to 6 carbon atoms, R3 is an alkyl group having 1 to 6 carbon atoms, and X is -CsN, and Y is an aromatic group. And the organic compound having the formula (I), any one or one of the hydrogen atoms on the carbon atom of 0424-A20507TWF(N2); 02930002; phoelip 8 1290166, if necessary, may be the same or different fluorine atoms, The halogen atom, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms or an amine group is substituted. Further, the liquid crystal additive has a birefringence An of not less than 0.3, a liquid crystal phase range of not less than 80 QC, and a solubility (solubility) of the liquid crystal additive and a chiral dopant of not less than 20 %. According to a preferred embodiment of the present invention, the compound having the formula (I) wherein Y is a benzene ring, X is -ON, R1 is an alkyl group having 1 to 6 carbon atoms, and R 2 is hydrogen. And R3 is an alkyl group having 1 to 6 carbon atoms, and the organic compound having the formula (I), the hydrogen on any one or more of the carbon atoms thereof may be the same or different fluorine atom as needed And a halogen atom, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms or an amine group. According to another preferred embodiment of the present invention, the compound having the formula (1) wherein Y is a benzene ring, may be, for example, a phenyl group or a biphenyl group, the X system is -ON, and the R1 system has 1 to 6 carbon atoms. An alkyl group, R 2 is hydrogen, and R 3 is an alkyl group having 1 to 6 carbon atoms, and the organic compound having the formula (I), any one or more of the carbon atoms thereon, It is required to be substituted by the same or different fluorine atom, a halogen atom, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms or an amine group. Further, the liquid crystal additive having a high birefringence according to the present invention may also be an organic compound including the formula (II).

Wherein R1 or R2 is hydrogen, fluorine, or an alkyl group having 1 to 6 carbon atoms, R3 is 0424-A20507TWF(N2); 02930002; phoe!ip 9 1290166 is an alkyl group having 1 to 6 carbon atoms, Whereas the X system is -ON or -N=C, the organic compound having the formula (1), any one or one of the hydrogens on the h, if necessary, may be the same or different fluorine atoms, halogens > P 1 -6 An alkyl group of a carbon atom, an alkoxy group having 1 to 6 carbon atoms or an amine. The characteristics of the present invention are in the design of a liquid crystal additive, and the liquid worm has

The main structure in which the Z system is an aromatic having an alkyl group. The present invention has the above-mentioned special chemical structure of the liquid crystal additive to improve the chemical properties and physical photoelectric properties of liquid helium, and is intended to be applied to liquid crystal display. The liquid crystal additive of the present invention has a broad nematic liquid crystal. Less than 80 ° C), and has a lower melting point and heat of fusion, in addition, its cooking (Anrefringence, An) can be as high as 0.3, or even higher than 0.4. Furthermore, since the bag has a plurality of benzene rings (or aromatic groups) and has a higher C (viscosity, r(), it has excellent solubility for liquid crystal (Nematic Host) and chiral dopant having a palm center. Compatibility (so = not less than 20%. Another feature of the present invention is that the liquid crystal addition force 1 of the present invention = the terminal cyano group or the conjugate of the main structure (stilbene) double bond Thiocyanate = structural design, which can further reduce the variation of liquid crystal additive (Anref), and dielectric anisotro. It is worth noting that the liquid crystal additive of the present invention has benzene ring and aromatic 0424. -A20507TWF(N2);02930002;phoelip 10 1290166, and preferably 3. The present invention also relates to a liquid crystal composition characterized by comprising the liquid crystal additive of the above formula (I) or (II), the composition thereof At least: (a) 0.5 wt% to 35 wt% of at least one liquid crystal additive as defined by the above formula (I) or (Π) based on the total weight of the liquid crystal composition; and (b) 65 wt% to 99.5 Wt% liquid crystal based on the total weight of the liquid crystal composition, and its composition (a) Different, wherein the liquid crystal composition has an operating temperature in the range of -10 to 50 ° C, a storage temperature in the range of -40 to 80 ° C, and the liquid crystal composition has an optical and chemical stability. The system is greater than 20,000 hrs. The liquid crystal composition of the optically active high helical torsion liquid crystal additive of the present invention, wherein at least one of the components (a) is as defined in the above formula (I) A preferred ratio is from 5 wt% to 20 wt% 'based on the total weight of the liquid crystal composition. The liquid crystal composition may further comprise another component (0 additive which is different from component (a) and component (b). Further, the liquid crystal of the component (b) may be a twisted nematic (TN) liquid crystal, a super twisted tantalum (STN) liquid crystal, a color super twisted nematic (SSTN) liquid crystal or a thin film transistor type (TFT) liquid crystal. The liquid crystal composition of the invention has a high birefringence liquid crystal additive, which not only has excellent birefringence, but also increases the reflectivity of the liquid crystal display, and has low temperature dependence and high light stability, and can be used as a liquid crystal display. One of the liquid crystal components, suitable For the purpose of fabricating a liquid crystal display device. In order to meet another object of the present invention, the present invention provides a liquid crystal display having a high reflectivity, which comprises a liquid crystal with high birefringence as described in the above formula (1) or (π). The liquid crystal display has a reflectance of not less than 35%, a driving voltage of less than 25V, and a contrast ratio of not less than 1〇: 1°. According to the present invention, the liquid crystal display may be a reflective SSOT. -A20507TWF(N2);02930002;phoelip 11 1290166 or polymer dispersed (PDLC) liquid crystal display. The above and other objects and features of the present invention will become more apparent from the following detailed description. A liquid crystal additive, a liquid crystal composition containing the liquid crystal additive, and a liquid crystal display. The liquid crystal additive of the present invention is a chemical structure having the formula (I) or the formula (II), except that R1, R2, R3, X and Y may be substituted or combined with different groups, and Any one or more carbon atoms in the structure, wherein the hydrogen on the same may be the same or different fluorocarbon, halogen atom, alkyl group having 1 to 6 carbons or alkoxylate having 1 to 6 carbons. Substituted by the base. Table 2 series of examples of novel high birefringence liquid crystal additives having the structure of formula (I) or formula (II) according to the present invention, comprising 18 stilbene having different structures or The chemical structures of the oxime derivatives are detailed in the table, so that the different R1, R2, R3, X and Y can be clearly identified, and the liquid crystal phase ranges thereof are also listed. The measurement method of the compound was analyzed by nuclear magnetic resonance, infrared spectrometer and mass spectrometry, and the liquid crystal phase was identified by a thermal analyzer and a polarizing microscope. 0424- A20507TWF(N2);02930002;phoeHp 12 1290166

Liquid crystal additive compound structure liquid crystal phase range 1 h3c-〇-〇-v^_cn > 80 ° C 2 > 110 ° C 3 > 120 ° C 4 133 ° C 5 > 125 ° C 6 > 80 °C 7 C2H5〇\ C6Hi3~^^^^yNCS - 8 F >85°C 9 Ci >80°C 0424-A20507TWF(N2);02930002;phoelip 13 1290166 10 >85°C 11 >80 °C 12 >70°C 13 >7 0°C 14 >110°C 15 C3H7_^K^i^^NCS >95°C 16 C4H9O^^^^_ncs >130°C 17 C5Hii~ 〇^^^^^ncs >120°C 18 C6Hi3O~^^^_ncs >125°C Table 2: High-birefringence liquid crystal additives having the formula (I) or formula (II), please refer to the following The reaction formula (1) and the reaction formula (Π) are illustrative of the synthesis scheme of the liquid crystal additive having the formula (I) or the formula (II) of the present invention having 0424-A20507TWF(N2); 02930002; phoelip 14 1290166. Η3—Y—NH2

Na£l〇2 HC1 or ΚΙ i 1

R3—Y- I R=l or λν Η3—Y—Cl /

R2HC M9rl2

H1 <2 CHH^

Pd (OAc) 2 rP (o-tol) 3 1 -Bromobenzonitr 1 e R3

15 0424-A20507TWF(N2);02930002;phoelip 1290166

R3—Υ—NH2 NaN〇2 HC1 or KI R3—Y—I or R3—Y—Cl

H2HC

Br

Mg, work 2 R3-

R1 I1-1

CHR 2

Pd (OAc) 2 rP C〇-tol) 3 l -BramDaniline

2

NCS In the reaction formula (I) and the reaction formula (II), R1 or R2 is hydrogen, fluorine, or an alkyl group having 1 to 6 carbon atoms, and R3 is an alkyl group having 1 to 6 carbon atoms. X is -ON or -N=C=S, Y is a benzene ring or an aromatic group, and any benzene ring, aryl group or alkyl group, hydrogen of any one or more of the carbon atoms thereof, Requires an alkoxy group or an amine group which may be the same or different fluorine atom, a halogen atom, an alkyl group having 1 to 6 carbon atoms, 0424-A20507TWF(N2); 02930002; phoelip 16 1290166 having 1 to 6 carbon atoms Replaced. Hereinafter, the compounds 2 to 6 and the compounds 14 to 18 in the above Table 1 are exemplified, and the preparation methods thereof are described in detail in Examples 1 to 10, respectively. Example 1 Synthesis of Liquid Crystal Additive 2 2 g (9.0 mmol) of 4-(4-ethylphenyl)-α-mercaptostyrene (4-(4-Ethylphenyl)-a-methylstyrene), 1· 37 g (7.5 mmol) 4_^~benzonitrile (4-Bromobenzonitrile), 0. 02 g (0.09 mmol) Pd(OAc) 2 (palladium acetate) and 0·3 g (1.0 mmol) P(o-tol) 3 (tri-o-tolylphosphine), dissolved in 4 ml of triethylamine and 8 ml of acetonitrile, placed in a high pressure bottle, and heated to 80 ° C for 2 to 4 days. Finally, it was diluted with dichloromethane and washed with water and saturated brine, and dried over anhydrous sulfuric acid. After concentration and chromatography on a silica gel column, a white solid was obtained in a yield of 27.6%, and the spectral analysis of the liquid crystal additive 2 was as follows: 4 NMR (CDC13, /7 (4): δ1·23~1.29 (t, 3H, Ph-CH2-Cii3), 2.30(s,3H,α-methyl), 2.65~2_72(q,2H,Ph-CSz-),6·85 (s, 1H,C-(CH3)=CiiPh), 7.26 ~ 7.29 (d, 2H, aromatic protons), 7.43~7.46 (d, 2H, aromatic protons), 7.52~7.66 (m, 8H, aromatic protons). Example 2 Synthesis of liquid crystal additive 3 as in the example 1 in the same manner, but replacing 4-(4-ethylphenyl) with 9-0 mmol of 4-(4-propylphenyl)-α-methylstyrene (4-(4-propylphenyl)-a-methylstyrene) -a-methylstyrene (4-(4-Ethylphenyl)-a-0424-A20507TWF(N2); 02930002; phoelip 17 1290166 methylstyrene) as a starting material, the yield is 20.0%, and the liquid crystal additive The spectral analysis of 3 is as follows: 4 NMR (CDC13, j^pm): 50.96~1.01 (t, 3H), 1.65~1.73 (m, 2H, Ph-CH2-CH2-), 2.32 (s, 3H, α-methyl ),2·62~2.67(t,2H, Ph-C|i2_),6_87 (s,1H,C_(CH3)=CHPh),7·25~7.28(d,2H,aromatic proto Ns), 7.45 to 7.48 (d, 2H, aromatic protons), 7.53 to 7.67 (m, 8H, aromatic protons) 〇 Example 3 Synthesis of liquid crystal additive 4 was carried out in the same manner as in Example 1, but with 9.0 mmol 4-(4-butylphenyl)-a-methylstyrene substituted 4-(4-ethylphenyl)-α-methylstyrene (4-(4_Ethylphenyl) -a-methylstyrene) as a starting material, the yield was 34.2%, and the spectral analysis of the liquid crystal additive 4 was as follows: 4 NMR (CDCl3, ;?; 7m): 30.83~0.87 (t, 3H, Ph-(CH2) )3-Ca3), 1·26~1.33 (m, 2H, Ph-(CH2)2-CE2-), 1.48~1.57 (m, 2H, Ph-CH2_Cii2_), 2.22 (s, 3H, α-methyl) , 2.53~2.59(t, 2H, Ph-CI^-), 6.77 (s' 1H, C-(CH3)=QlPh), 7.1~7.18(d, 2H, aromatic protons), 7.35~7.38(d , 2H, aromatic protons), 7.43~7.58 (m, 8H, aromatic protons). Example 4 Synthesis of Liquid Crystal Additive 5 was carried out in the same manner as in Example 1, except that 9.0 mmol of 4-(4-pentylphenyl)-α-methylstyrene (4-(4-pentylphenyl)- Α-methylstyrene) substituted 0424-A20507TWF(N2); 02930002; phoelip 18 1290166 4-(4-ethylphenyl)-α-methylstyrene (4-(4-Ethylphenyl)-a-methylstyrene) as starting material, The yield was 22.8%' and the spectral analysis of the liquid crystal additive 5 was as follows: lR NMR (CDCl3?jp^m): 50.86^0.91 (t ^ 3H ^ Ph-(CH2)4-CH3) » 1.33~1.39 (m , 4H, Ph-(CH2)2-(Cii2)3-CH3), 1_54~1.66 (m, 2H, Ph-CHrCiL-), 2.30 (s, 3H, a-methyl), 2.60~2.65 (t, 2H , Ph-CiL-), 6.85 (s, 1H, C-(CH3)=CiiPh), 7.24~7.26(d, 2H, aromatic protons) ^ 7.43-7.46(dj 2H j aromatic protons) 5 7.47-7.66 (m 5 8H, aromatic protons) ° Example 5 Synthesis of liquid crystal additive ό in the same manner as in Example 1, but with 9.0 mmol of 4-(4-hexylphenyl)-α-mercaptophenyl Substituting 4-(4-hexylphenyl)-a-methylstyrene for 4-(4-ethylphenyl)-(x-methylstyrene(4-(4_Ethylphenyl)_a_meth Yristide) as a starting material, the yield was 33.4%, and the spectral analysis of the liquid crystal additive 4 was as follows: 4 NMR (CDC13, ρ/^)··δ0·79~0.83 (t, 3H, Ph_(CH2)5 -CIi3), 1.23~1.31(m,6H,Ph-(CH2)2-(Cii2)3-CH3),1·54~1.59(m,2H), 2-23(s,3H,(x-methyl ), 2.54~2.59(t, 2H, Ph-CiL-), 6.78(s, 1H, C-(CH3)=C£[Ph), 7.16~7·17(d, 2H, aromatic protons), 7.35~ 7.38 (d, 2H, aromatic protons), 7.44 to 7.58 (m, 8H, aromatic protons) o Comparative Example 1 A conventional liquid crystal additive having a similar structure, 5-PPP-CN, having the following 0424-A20507TWF (N2) );02930002;phoelip 19 1290166 chemical structure:

Referring to Table 3, the phase transition temperatures and enthalpy values of the liquid crystal additives obtained in Examples 1 to 5 and the conventional liquid crystal additives shown in Comparative Example 1 are shown. Referring to Fig. 2, the phase transition temperature analysis diagrams of the liquid crystal additives of Examples 1 to 5, as shown in the figure, the liquid crystal additives shown in Examples 1 to 5 have a melting point (K) of about 91.6 ° C to 138.8 °. Between C, the tendency of the odd-even effect is not obvious as the terminal carbon chain (R3) increases. However, the liquid crystal additives shown in Examples 1 to 5 have a clearing point (I) temperature along with the terminal carbon chain (R3). The carbon number increases and decreases, and there is a tendency to have a parity effect. The thermal enthalpy averages 3 Kcal/mol, while the liquid crystal phase ranges from 83.6 ° C to 133.0 ° C, both of which are nematic phases. Compound phase transition temperature (°C) and enthalpy (KCal /m〇1) Liquid crystal additive 2 (Example 1) Temperature rise K 138.8 (ΔΗ: 5·64〇) N 251.5 (ΔΗ··0·332) 209·0 (ΔΗ: 0·055) Ν 87·6 (ΔΗ: -3·481) 液晶 Liquid crystal additive 3 (Example 2) Temperature rise Κ 105·4 (ΔΗ: 2.319) Ν 238·4 (ΔΗ: 0·068) Cooling down I 232.1 (----) Ν 79.2 (ΔΗ: -1.169) 液晶 Liquid crystal additive 4 (Example 3) Temperature rise · Κ 93·7 (ΔΗ: 3·432) Ν 219_2 (ΔΗ· · 0·176) Work temperature drop 218·4 (ΔΗ: -0·158) Ν 72·1 (ΔΗ: -3.174) 液晶 Liquid crystal additive 5 (Example 4) Temperature rise Κ 91.6 (ΔΗ: 2.576) Ν 218.9 ( ----) I Cooling work 207·3 (ΔΗ: -0·146) Ν 71.2 (ΔΗ: -2.375) 液晶 Liquid crystal additive 6 (Example 5) Temperature rise Κ 96.3 (ΔΗ: 3·767) Ν 179 ·9 (ΔΗ: 0.084) work temperature reduction 179.4 (ΔΗ: -0·061) Ν 79·4 (ΔΗ: -3·630) Κ 5-PPP-CN (Comparative Example 1) kl30 N239 Table 3 3, it can be seen that liquid crystal additive 5, 0424-A20507TWF (N2); 02930002: phoelip 20 1290166 with a similar structure to 5-PPP-CN reduces its melting point by about 39 4 较 compared with 5-PPP-CN, and the clarification point drops by 21 1 art, LCD phase range increased by 18.3. (:, this means that its onion-based structure does make a substantial contribution to the improvement of liquid crystal properties. The conversion of the double bond into the benzene ring structure of the present invention also successfully reduces the melting point and clearing point of the compound, and increases the temperature of the liquid crystal phase. The range of the liquid crystal additive 14 was prepared by dissolving 0.5 g (5 mmol) of calcium carbonate in 6 ml of H20 and 3 ml of chloroform (CHC13), followed by adding 0.6 g (5 mm〇i) of dichlorosulfide under ice bath. Carbon (thiophosgene) and homogeneously mixed. Next, le32g (4.2 mmol) of 4-(4-ethylphenylamine-α-methylstyrene MH-EthylphenyU-f-amiiio-a- Inethylstilbene) is dissolved in 15 ml of chloroform (CHC13) and added to the above mixed solution. After stirring for 1 to 5 hours at 35 ° C, it is diluted with a milky product (CH2C12). The organic layer is washed with water and i% jjCl, and then anhydrous. The mixture was dried over magnesium sulfate, concentrated and purified by silica gel column chromatography to afford white crystals (yield: 98 g, yield: 98.7%), and the spectral analysis of the liquid crystal additive 14 as follows: 4 NMR (CDC13, ρ,): δ 1.25~ L_30(t,3H,Ph-CH2-Cii3), 2.30(s,3H,a-methyl),2·67~2.73(q,2H,Ph-CiL-),6·83 (s 1H,C-(CH3)=CiiP]i),7·22~7.30(m,4H,aromatic protons), 7.34~7.37(d,2H,aromatic protons),7.53~7.61 (m,6H,aromatic protons) o Example 7 Synthesis of liquid crystal additive 15 in the same manner as in Example 6, but with 4.2 mmol of 4-(4-propylphenyl)-4, - 0424-A20507TWF (N2); 02930002; phoelip 21 1290166 Amine-(X-methylstyrene(4-(4-propylphenyl)_4,-ammo-a-methylstilbeiie) substituted 4-(4-ethylphenyl)-4'-amine methylstyrene (4-(4) -Ethylpheiiyl)_4'-ammo-a-metliylstilbeiie) as a starting material, the yield was 99.3%, and the spectral analysis of the liquid crystal additive 15 was as follows: 4 NMR (CDC13, ρ; 77η): δ 0.88 to 0.93 (t ,3H,Ph-(CH2)2-CIi3), 1·57~l-65(m,2H,Ph_CH2-C|i2_), 2.23(s,3H,a_methyl), 2.54~2.59(t,2H,Ph -CiL··), 6.76 (s, 1H, C-(CH3)=CSPh), 7.15~7.20 (m, 4H, aromatic protons), 7.27~7.29 (d, 2H, aromatic protons), 7.46~7.55 (m , 6H, aromatic protons) o Example 8 Synthesis of liquid crystal additive 16 was carried out in the same manner as in Example 6, but with 4.2 mmol of 4_(4_ 4-(4-butylphenyl)-4'-amino-a-metliylstilbeiie Substituted 4-(4-ethylphenyl)-4'- As a starting material, 4-(4-Ethylphenyl)-4'-ammo-ct-methylstilbeiie) has a yield of 92.5%, and the spectral analysis of the liquid crystal additive 15 is as follows: ~0.90(t,3Η,Ph-(CH2)3-Cii3), 1·28~1.36(m,2H,Ph-(CH2)2-C|i2-), 1.54~1.60(m,2H, Ph- CH2-CE2-), 2.23 (s, 3H, a-methyl), 2.56~2.61 (t, 2H, Ph-CiL-), 6_76 (s, 1H, C-(CH3)=CEPh), 7_15~7_21 ( m,4H, aromatic protons) » 7.27-7.30(d > 2H 5 aromatic protons) j 7.45~7.55(m,6H,aromatic protons) 0 Example 9 Synthesis of liquid crystal additive 17 0424-A20507TWF(N2);02930002 ;phoelip 22 1290166 was carried out in the same manner as in Example 6, except that 4.2 mmol of 4-(4-pentylphenyl)-4,amine-α-methylstyrene (4-(4-pentylpheiiyl)- 4,-amiiio_a-methylstilbene) is substituted for 4-(4-ethylphenyl)-4,-amine-a-methylstilbene (4-(4-Ethylphenyl)-4'-amino-a-methylstilbene) Yield, 95.9%, and The spectral analysis of the crystal additive 15 was as follows: 1H NMR (CDC135 0·88~0.92 (t, 3H, Ph-(CH2)4-CE3), 1.32~1.38 (m, 4H, Ph_(CH2)2- (CSL2) 3-G:H3), 1.56~1.66(m,2H, Ph-CH2-Cii2-), 2.3〇(s,3H,a-methyl), 2.62~2.67(t,2H, Ph-d),6· 83 (s,1H,C-(CH3)=CiiPli), 7.22~7.27(m,4H, aromatic protons), 7.34~7.36(d,2H,aromatic protons), 7.52~7.61(m,6H, aromatic protons) o Example 10 Synthesis of liquid crystal additive 18 was carried out in the same manner as in Example 6, but with 4.2 mmol of 4-(4-hexylphenyl)-4'-amine_«-decylstyrene (4- (4_hexylplienyl)-4'-amiiio_a-methylstilbene) Substituting 4-(4-ethylphenyl)-4'-amine-a-methylstyrene (4-(4-Ethylphenyl)-4'_ammo-a-methylstilbene As a starting material, the yield was 97.2%, and the spectral analysis of the liquid crystal additive 15 was as follows: 4 NMR (CDC13, 卯所): 3 0·80~0.84 (t, 3H, Ph-(CH2)5- Cii3), 1.25~1.33 (m, 6H, Ph-(CH2)2-(C|L)3-CH3), 1.52~1.60 (m, 2H, Ph-CH2-CH2-), 2.23 (s, 3H, A-methyl), 2_55~2.60 (t, 2H, Ph-Cii2-), 6.76 (s, lH C-(CH3)=C|iPh), 7.15~7.20(in,4H, aromatic protons), 7.27~7.30(d,2H,aromatic protons), 7.45~7.55(m,6H,aromatic protons) ° 0424-A20507TWF (N2); 02930002; phoelip 23 1290166. Comparative Example 2 A conventional liquid crystal additive 3-PPTP-NCS having a similar structure, which has the following chemical structure:

Referring to Table 4, the phase transition temperatures and enthalpy values of the liquid crystal additives obtained in Examples 6 to 10 and the conventional liquid crystal additives shown in Comparative Example 2 are shown. Referring to Fig. 3, the phase transition temperature analysis diagrams of the liquid crystal additives of Examples 1 to 5, as shown in Fig. t, the liquid crystal additives shown in Examples 6 to 10 have a melting point (K) of about 1.0 ° C to 12 0.1. Between °C, it can be seen that as the terminal carbon chain (R3) increases, both the melting point and the clearing point have a tendency to have a parity effect. In terms of the liquid crystal phase range, the range is from 99.1 ° C to 133.8 ° C. Further, when the length of the terminal carbon chain (R3) exceeds four or more, the liquid crystal phase has a smectic phase, and the temperature range of the smectic phase ranges from 27.2 ° C to 48.8 ° C, and with the carbon number The increase in the range of the stratification phase has continued to expand. 0424-A20507TWF(N2);02930002;phoelip 24 1290166 Compound phase transfer temperature (°C) and enthalpy (Kcal/mol) Liquid crystal additive temperature Κ 120·1 (ΔΗ:3·215) Ν 232·3 (ΔΗ: 0·171)Work 14 (Example 6) Cooling down work 233·3 (ΔΗ··-0.149) Ν 121·3 (ΔΗ: -1·815) 液晶 Liquid crystal additive temperature rise Κ 93·7 (ΔΗ:1·484 ) Ν 192.8 (ΔΗ··0·052) work 15 (Example 7) Cooling temperature I 203·8 (ΔΗ: -0.019) Ν 80·8 (ΔΗ: -1·267) 液晶 Liquid crystal additive temperature rise Κ 92·0 (ΔΗ: 2·480) SA 119.2 (ΔΗ: 0·077) Ν 16 (Example 8) 226·0 (ΔΗ: 0·278) work temperature reduction 226.6 (ΔΗ: -0.209) SA 118.3 (ΔΗ: -0 · 056) Ν 82·9 (ΔΗ: -2.362) 液晶 Liquid crystal additive temperature rise Κ 81.0 (ΔΗ: 1.203) SA 112.2 (ΔΗ: 0.059) Ν 206.1 17 (Example 9) (ΔΗ: 0·167) 206.5 (ΔΗ: -0.216) SA111·0 (ΔΗ: -0.036) Ν 77.5 (ΔΗ: -1.157) Κ Liquid crystal additive temperature rise Κ 86.2 (ΔΗ: 1.616) SA 135.0 (ΔΗ: 0.088) Ν 211.6 18 (Example 10) (ΔΗ: 0·260) cooling I 210.7 (ΔΗ: -0·190) SA134·5 (ΔΗ: -0.050) Ν 84.1 (ΔΗ: -1.576) Κ 3-PPTP-NCS (Comparative Example 2) Κ 200 S209 Ν266 I ΔΗ Table 4 It can be seen from Table 4 that the liquid crystal additive 15 having a similar structure to 3-PPTP-NCS has a melting point lower than that of 3-PPTP-NCS by about 106.3 ° C and a clearing point of 73.2. At °C, the liquid crystal phase range was increased by 33.1 °C and there was no smectic phase. This is because the double bond between the phenyl groups is softer than the triple bond, and the molecular interference is easily caused, so that the melting point and the clarification point can be lowered, and the occurrence of the elimination of the smectic phase is eliminated. The composition of the liquid crystal composition: The present invention further utilizes the liquid crystal additives 2 and 15 to formulate a new liquid crystal combination 0424-A20507TWF (N2); 02930002; phoelip 25 1290166 '', please refer to the following examples: 11 Liquid crystal composition (A) The liquid crystal additive 2 prepared in Example 1 was mixed with ZLI-1565 (manufactured by Merck Co., Ltd.) as a blending molecule in such a manner that the liquid crystal additive of the present invention was 1:9. The ratio was mixed with ZLI-1565, and the weight concentration ratio of the liquid crystal additive 2 was 10% (based on the total weight of the liquid crystal composition). The obtained liquid crystal composition (A) was measured for its birefringence by a krypton laser having a wavelength of 633 nm, and the measurement temperature was 23 ° C, and the results are shown in Table 5. The liquid crystal additive 2 of the present invention can be inferred by the inverse method to have an An of 0.3620. Example 12 Liquid crystal composition (B) The liquid crystal additive 15 prepared in Example 7 was mixed with ZLI-1565 (manufactured by Merck Co., Ltd.) as a blending molecule by disposing the liquid crystal additive of the present invention as 1 The ratio of 9 was mixed with ZLI-1565, and the weight concentration ratio of the liquid crystal additive 2 was 10% (based on the total weight of the liquid crystal composition). The obtained liquid crystal composition (B) was measured for its birefringence by a krypton laser having a wavelength of 633 nm, and the measurement temperature was 23 ° C, and the results are shown in Table 5. The liquid crystal additive 2 of the present invention can be inferred by the inverse method to have a Δη of 0.4618. 0424-A20507TWF(N2);02930002;phoelip 26 1290166 liquid crystal cell distance (density) birefringence viscoelastic coefficient liquid crystal additive birefringence unmixed ZLM565 14.8 0.1214 10.1 ... liquid crystal composition (A) (Example I2 14.74 0.1454 12.99 0.362 Liquid crystal composition (B) (Example 12) 14.25 0.1554 10.645 0.4618 Table 5: Measurement of birefringence and viscoelastic coefficient In summary, the liquid crystal additive of the present invention has a larger Birefringence, low viscosity, low refining point, good photothermal stability, wide liquid crystal phase temperature range, and excellent solubility for liquid crystal (Nematic Host), it is very suitable as a liquid crystal additive for reflective liquid crystal displays. Further, the liquid crystal additive of the present invention has high mutual solubility with a liquid crystal precursor (e.g., ZLI-1565), and even when it is added to 30%, no precipitation occurs. Furthermore, the portable liquid crystal display that can be used outdoors is a trend of development, and therefore the display is extremely important for temperature dependence and light stability. The novel optically active molecules of the present invention are highly suitable for use in reflective displays for liquid crystal formulations with high photostability and low temperature dependence. While the present invention has been described in its preferred embodiments, the present invention is not intended to limit the invention, and the present invention may be modified and modified without departing from the spirit and scope of the invention. The scope of protection is subject to the definition of the scope of the patent application. 1290166 [Simple description of the drawing] Fig. 1 is a schematic diagram showing the relationship between the birefringence An of the liquid crystal material and the reflection spectrum width Δλ. Fig. 2 is a graph showing the phase transition temperature of the liquid crystal additives of Examples 1 to 5. Fig. 3 is a graph showing the phase transition temperature of the liquid crystal additives of Examples 6 to 10. [Main component symbol description] No 0 0424-A20507TWF(N2);02930002;phoelip 28

Claims (1)

1290166 X. Patent application scope: 1. A liquid crystal additive having a high birefringence, comprising an organic compound as shown in formula (I), Formula (I) wherein R1 or R2 is hydrogen, fluorine, or an alkyl group having 1 to 6 carbon atoms, R3 is an alkyl group having 1 to 6 carbon atoms, and X is -C=N or - N=C=S, Y is an aromatic group, and the organic compound having the formula (I), the hydrogen on any one or more of the carbon atoms thereof may be the same or different fluorine atom or halogen atom as needed. Substituting an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms or an amine group. 2. The liquid crystal additive having a high birefringence according to claim 1, wherein the liquid crystal additive has a birefringence An of not less than 0.3. 3. The liquid crystal additive having a high birefringence according to claim 1, wherein the compound having the formula (I) is a benzene ring, the X system is -C=N, and the R1 system is 1 An alkyl group of 6 to 6 carbon atoms, R 2 is hydrogen, and R 3 is an alkyl group having 1 to 6 carbon atoms, and the organic compound having the formula (I), any one or more of its carbon atoms The hydrogen may be substituted with the same or different fluorine atom, a halogen atom, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms or an amine group, as needed. 4. The liquid crystal additive having a high birefringence according to claim 1, wherein the compound having the formula (1) is a benzene ring, the X system is -ON, and the R1 is hydrogen or a decyl group. R2 is hydrogen or an alkyl group having 1 to 6 carbon atoms, and R3 is an alkyl group having 1 to 6 carbon atoms, and the organic compound having the formula (I) is 0424-A20507TWF(N2); 0293002 ;phoelip 29 1290166, a hydrogen on any one or more of its carbon atoms, optionally containing the same or different I atom, a halogen atom, a burning group containing 1-6 carbon atoms, containing 1 -6 Substituted by an alkoxy group or an amine group of a carbon atom. 5. The liquid crystal additive having a high birefringence according to claim 1, wherein the compound having the formula (I) has a Y system of a benzene ring, and the X system is -N=C=S, and the R1 system is An alkyl group having 1 to 6 carbon atoms, R 2 is hydrogen, and R 3 is an alkyl group having 1 to 6 carbon atoms, and the organic compound having the formula (I), any one or more of the carbon The hydrogen on the atom may be optionally substituted by the same or different fluorine atom, a halogen atom, a burnt group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms or an amine group. 6. A liquid crystal additive having a high birefringence according to claim 1, wherein the compound having the formula (I) has a Y system of a benzene ring, an X system of -N=C=S, and an R1 system. Hydrogen or methylal, R2 is hydrogen or an alkyl group having 1 to 6 carbon atoms, and R3 is an alkyl group having 1 to 6 carbon atoms, and the organic compound having the formula (I) is optional Hydrogen on one or more carbon atoms, if desired, may be the same or different fluorine atom, halogen atom, alkyl group having 1 to 6 carbon atoms, alkoxy group having 1 to 6 carbon atoms or amine Substituted by the base. 7. The liquid crystal additive having a high birefringence according to claim 1, wherein the liquid crystal phase of the liquid crystal additive is not less than 80 QC. 8. The high birefringence liquid crystal additive according to claim 1, wherein the liquid crystal additive has a solubility of not less than 20% with respect to a chiral dopant. 9. A liquid crystal additive having a high birefringence, comprising an organic compound as shown in formula (II), 0424-A20507TWF(N2); 02930002; phoelip 30 1290166 Formula (π) wherein R1 or R2 is hydrogen, fluorine, or an alkyl group having 1 to 6 carbon atoms, R3 is an alkyl group having 1 to 6 carbon atoms, and X is -C=N or - N=C=S, and the above-mentioned organic compound having the formula (I), the hydrogen on any one or more of the carbon atoms, if necessary, may be the same or different fluorine atom, halogen atom, and containing 1-6 Substituted by an alkyl group of a carbon atom, an alkoxy group having 1 to 6 carbon atoms or an amine group. 10. The liquid crystal additive having a high birefringence according to claim 9, wherein the liquid crystal additive has a birefringence An of not less than 0.3. 11. The liquid crystal additive having a high birefringence according to claim 9, wherein the liquid crystal phase of the liquid crystal additive is not less than 80 °C. 12. The high birefringence liquid crystal additive according to claim 9, wherein the liquid crystal additive has a solubility of not less than 20% with respect to a chiral dopant. 13. A liquid crystal composition comprising at least: (a) 0.5 wt% to 35 wt% of at least one liquid crystal addition having a high birefringence as described in claim 1 of the total weight of the liquid crystal composition And (b) 65 wt% to 99.5 wt% of the liquid crystal based on the total weight of the liquid crystal composition, which is different from the component (a), wherein the liquid crystal composition has an operating temperature of -10 to 50 ° C. Within the range, the storage temperature is in the range of -40 to 80 ° C, and the liquid crystal composition has an optical and chemical stability of more than 20,000 hrs. 14. The liquid crystal composition according to claim 13, wherein the liquid crystal additive having a high birefringence of the component (a) accounts for 5 wt% to 20 wt%/〇 of the liquid crystal composition. A liquid crystal composition according to claim 13 wherein the component (b) liquid crystal is a twisted nematic (TN) liquid crystal, a super twisted nematic plastic film, which is a liquid crystal composition according to claim 13 of the invention. (STN) liquid crystal, color super twisted nematic (SSTN) liquid crystal or thin film transistor type (TFT) liquid crystal. 16. A liquid crystal composition comprising at least: (a) at least one of 0.5 wt/〇 to 35 wt% based on the total weight of the liquid crystal composition, having a high birefringence as described in claim 9 a liquid crystal additive; and (b) 65 wt% to 99.5 wt% of a liquid crystal based on the total weight of the liquid crystal composition, which is different from the component (a), wherein 'the liquid crystal composition has an operating temperature of -10 to 50 Å. Within the range of C, the storage temperature is in the range of -40 to 80 ° C, and the liquid crystal composition has an optical and chemical stability of more than 2 Å, 〇〇〇hrs. The liquid crystal composition according to claim 16, wherein the liquid crystal additive having a high birefringence of the component (4) accounts for 5 wt% to 20 wt% of the liquid crystal composition. 18. The liquid crystal composition according to claim 16, wherein the component (b) liquid crystal is a twisted nematic (TN) liquid crystal, a super twisted nematic (STn) liquid crystal, or a color super twisted nematic ( SSTN) Liquid crystal or thin film transistor type (TFT) liquid crystal. A liquid crystal display having a high reflectivity, comprising the liquid crystal additive having a high birefringence according to claim 1, wherein the liquid crystal display has a reflectance of not less than 35% and a driving voltage system is less than 25v, and the contrast is not less than 10:1. 20. A liquid crystal display having a higher reflectivity as described in claim 19, wherein the liquid crystal display is a reflective SSCT display or a polymer dispersed (PDLC) liquid crystal display. A liquid crystal display having a high reflectivity, comprising a liquid crystal additive having a high birefringence according to claim 9 of the patent application, wherein the liquid crystal display has a reflectance of not less than 35%, and a driving voltage system Less than 25v, and the contrast is not small 0424-A20507TWF (N2); 02930002; phoellp 32 1290166 at 10:1. 22. The liquid crystal display having a higher reflectivity as described in claim 21, wherein the liquid crystal display is a reflective SSCT display or a polymer dispersed (PDLC) liquid crystal display. 0424- A20507TWF(N2);02930002;phoelip 33