LIQUID CRYSTAL COMPOSITION AND USE THEREOF

Abstract

A liquid crystal composition includes at least one polar compound represented by Formula (I), at least one polar compound represented by Formula (II), at least one compound represented by Formula (III), and at least one compound represented by Formula (IV), in which Formulae (I) to (IV) are as defined herein.

Claims

1. A liquid crystal composition, comprising: at least one polar compound represented by Formula (I), ##STR00043## at least one polar compound represented by Formula (II), ##STR00044## at least one compound represented by Formula (III), ##STR00045## and at least one compound represented by Formula (IV), ##STR00046## wherein R.sub.1, R.sub.2, R.sub.3, R.sub.4, and R.sub.5 are each independently selected from the group consisting of hydrogen, an alkyl group having 1 to 7 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an alkenyl group having 2 to 7 carbon atoms, and an alkenoxy group having 3 to 5 carbon atoms, wherein each of said alkyl group, said alkoxy group, said alkenyl group, and said alkenoxy group is unsubstituted or substituted with fluorine; ##STR00047## each independently represent a member selected from the group consisting ##STR00048## each independently represent at least one member selected from the group consisting of ##STR00049## L.sub.1 and L.sub.2 are each independently selected from the group consisting of hydrogen and fluorine; X.sub.1 and X.sub.2 are each independently selected from the group consisting of fluorine, chlorine, an alkyl group having 1 to 6 carbon atoms, a haloalkyl group having 1 to 6 carbon atoms, an alkenyl group having 2 to 6 carbon atoms, a haloalkenyl group having 2 to 6 carbon atoms, a haloalkoxy group having 1 to 6 carbon atoms, and a haloalkenoxy group having 2 to 6 carbon atoms; m represents 0 or 1; and n represents 0, 1, or 2, with the proviso that when m represents 2, two of ##STR00050## may be the same or different, and when n represents 0, ##STR00051## are not ##STR00052## at the same time.

2. The liquid crystal composition according to claim 1, wherein said polar compound represented by Formula (I) is selected from the group consisting of compounds of Formulae (I-1) to (I-13), ##STR00053## ##STR00054##

3. The liquid crystal composition according to claim 1, wherein said polar compound represented by Formula (II) is selected from the group consisting of compounds of Formulae (II-1) to (II-3), ##STR00055##

4. The liquid crystal composition according to claim 1, wherein said compound represented by Formula (III) is selected from the group consisting of compounds of Formulae (III-1) and (III-2), ##STR00056##

5. The liquid crystal composition according to claim 1, wherein said compound represented by Formula (IV) is selected from the group consisting of compounds of Formulae (IV-1) to (IV-21), ##STR00057## ##STR00058## ##STR00059##

6. The liquid crystal composition according to claim 1, wherein said polar compound represented by Formula (I) is in an amount ranging from 1 wt % to 20 wt %, said polar compound represented by Formula (II) is in an amount ranging from 1 wt % to 30 wt %, said compound represented by Formula (III) is in an amount ranging from 1 wt % to 70 wt %, and said compound represented by Formula (IV) is in an amount ranging from 1 wt % to 60 wt % based on 100 wt % of said liquid crystal composition.

7. A liquid crystal display comprising the liquid crystal composition according to claim 1.

Description

DETAILED DESCRIPTION

[0023] A liquid crystal composition according to the disclosure comprises:

[0024] at least one polar compound represented by Formula (I),

##STR00011##

[0025] at least one polar compound represented by Formula (II),

##STR00012##

[0026] at least one compound represented by Formula (III),

##STR00013##

and

[0027] at least one compound represented by Formula (IV),

##STR00014##

[0028] wherein

[0029] R.sub.1, R.sub.2, R.sub.3, R.sub.4, and R.sub.5 are each independently selected from the group consisting of hydrogen, an alkyl group having 1 to 7 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an alkenyl group having 2 to 7 carbon atoms, and an alkenoxy group having 3 to 5 carbon atoms, wherein each of said alkyl group, said alkoxy group, said alkenyl group, and said alkenoxy group is unsubstituted or substituted with fluorine;

##STR00015##

each independently represent a member selected from the group consisting

##STR00016##

each independently represent at least one member selected from the group consisting of

##STR00017##

[0030] L.sub.1 and L.sub.2 are each independently selected from the group consisting of hydrogen and fluorine;

[0031] X.sub.1 and X.sub.2 are each independently selected from the group consisting of fluorine, chlorine, an alkyl group having 1 to 6 carbon atoms, a haloalkyl group having 1 to 6 carbon atoms, an alkenyl group having 2 to 6 carbon atoms, a haloalkenyl group having 2 to 6 carbon atoms, a haloalkoxy group having 1 to 6 carbon atoms, and a haloalkenoxy group having 2 to 6 carbon atoms;

[0032] m represents 0 or 1; and

[0033] n represents 0, 1, or 2,

[0034] with the proviso that when m represents 2, two of

##STR00018##

may be the same or different, and when n represents 0,

##STR00019##

are not

##STR00020##

at the same time.

[0035] In certain embodiments, the polar compound represented by Formula (I) is selected from the group consisting of compounds of Formulae (I-1) to (I-13),

##STR00021## ##STR00022##

[0036] In certain embodiments, the polar compound represented by Formula (II) is selected from the group consisting of compounds of Formulae (II-1) to (II-3),

##STR00023##

[0037] In certain embodiments, the compound represented by Formula (III) is selected from the group consisting of compounds of Formulae (III-1) and (III-2),

##STR00024##

[0038] In certain embodiments, the compound represented by Formula (IV) is selected from the group consisting of compounds of Formulae (IV-1) to (IV-21),

##STR00025## ##STR00026## ##STR00027##

[0039] In certain embodiments, the polar compound represented by Formula (I) is in an amount ranging from 1 wt % to 20 wt %, the polar compound represented by Formula (II) is in an amount ranging from 1 wt % to 30 wt %, the compound represented by Formula (III) is in an amount ranging from 1 wt % to 70 wt %, and the compound represented by Formula (IV) is in an amount ranging from 1 wt % to 60 wt % based on 100 wt % of said liquid crystal composition.

[0040] A liquid crystal display according to the disclosure comprises the liquid crystal composition described above. When the liquid crystal composition according the disclosure is used in the IPS-TFT or FFS-TFT mode liquid crystal display, it is not necessary to further add a chiral material into the liquid crystal composition. When the liquid crystal composition according the disclosure is used in the TN-TFT mode or passive matrix mode liquid crystal display, it is necessary to further add into the liquid crystal composition, the chiral material in an amount of up to 1 wt % based on a total weight of the compounds of Formulae I to IV. In certain embodiments, additives such as ultraviolet stabilizers, dopants, and anti-oxidants can be added according to specific requirements.

[0041] Examples of the disclosure will be described hereinafter. It is to be understood that these examples are exemplary and explanatory and should not be construed as a limitation to the disclosure.

[0042] The liquid crystal composition according to the disclosure can be prepared by any methods well known in the art. For example, the compounds for preparing the liquid crystal composition are mixed and dissolved in an organic solvent at an elevated temperature to form a mixture, followed by removing the solvent from the mixture via distillation under reduced pressure, so as to obtain the liquid crystal composition. Alternatively, the compound(s) having relatively low amount(s) is (are) molten in the remaining compound(s) having relatively high amount(s) at a relatively elevated temperature to prepare the liquid crystal composition. Alternatively, each of the compounds for preparing the liquid crystal composition is separately dissolved in an organic solvent (for example, acetone, chloroform, methanol, or the like), followed by mixing together in a solvent to obtain a mixture and then removing the solvent from the mixture to obtain the liquid crystal composition.

[0043] In the specification, the percentage is given by weight percentage, the temperature is given by degree Celsius, and the symbols and the measurement conditions for various properties are described below if not stated otherwise.

1. Clear Point (Cp, C.):

[0044] A liquid crystal composition was observed using a microscope while being heated using a heater. The temperature at which the liquid crystal composition transformed from a liquid crystal phase to a liquid phase was recorded as a clear point of the liquid crystal composition.

2. Melting Temperature (SN, C.):

[0045] A liquid crystal composition was filled into a liquid crystal box, followed by placement of the liquid crystal box in a freezer at a temperature of 30 C. or 40 C. and observation of the crystalline state of the liquid crystal composition. The temperature at which the liquid crystal composition transformed from the crystalline state to a nematic phase was recorded as a melting point of the liquid crystal composition.

3. Optical Anisotropy (n):

[0046] Measurement was implemented at a wavelength of 589 nm and at a temperature of 25 C. using an Abbe refractometer (Manufacturer: ATAGO Co. Ltd., Japan). The optical anisotropy was calculated according to a formula as below.

n=neno,

wherein

[0047] ne is an refractive index of extraordinary light; and

[0048] no is an refractive index of ordinary light.

[0049] In order to meet the requirements for subsequent applications, the optical anisotropy (i.e., n) of the liquid crystal composition is preferably in a range from 0.065 to 0.200.

4. Dielectric Anisotropy ():

[0050] A liquid crystal composition sample was placed in a 25 m PAN cell in which no chiral dopant was added. Measurement was implemented at a temperature of 25 C. using a measurement instrument (Manufacturer: INSTEC; Model: ALCT-IR1). The dielectric anisotropy was calculated according to a formula as below.

=,

[0051] wherein

[0052] is a dielectric constant parallel to a molecular axis; and

[0053] is a dielectric constant transverse to a molecular axis.

[0054] In order to meet the requirements for subsequent applications, the dielectric anisotropy (i.e., ) of the liquid crystal composition is preferably in a range from 2 to 11.

5. Rotational Viscosity (1, mPa.Math.s):

[0055] A liquid crystal composition sample was placed in a 25 m PAN cell in which no chiral dopant was added. Measurement was implemented at a temperature of 250.2 C. using a measurement instrument (Manufacturer: INSTEC; Model: ALCT-IR1). The lower the rotational viscosity, the faster the response speed with the shorter the response time. In order to meet the requirements for subsequent applications, the rotational viscosity (i.e., 1) of the liquid crystal composition is preferably in a range from 25 mPa.Math.s to 110 mPa.Math.s.

[0056] The liquid crystal compositions in the following examples were prepared by a heat-dissolution process or a vibration-mixing process well known in the art. Specifically, the compounds for preparing each of the liquid crystal compositions were weighed in weight percentages, and were added into a container in unspecified order, preferably in an order in which the compound having a relatively high melting point was added before the compound having a relatively low melting point, followed by stirring or vibrating at a constant temperature of 60 C. to obtain a homogeneous mixture. The homogeneous mixture was treated via absorption, micro-filtration using a micro-filtration membrane, and then packaged to obtain a target sample.

[0057] The compounds used in the following examples can be obtained via well-known synthesis processes or via commercial purchase, and was confirmed via measurements to ensure that these compounds met the standards for electronic compounds.

[0058] For simple and clear representation, the groups contained in the compounds in the following examples are represented using the codes shown in Table 1.

TABLE-US-00001 TABLE 1 Code Group Code Group Code Group A [00028] G C.sub.2H.sub.4 P [00029] B [00030] H H Q CF.sub.2O C [00031] I CH.sub.2O T D M [00032] O5FA OCF.sub.2CFCF.sub.2 E COO N [00033] OTF OCF.sub.3 F F O O Y [00034]

[0059] For example, the chemical structures of some compounds and the groups contained therein are illustrated in Table 2 below.

TABLE-US-00002 TABLE 2 [00035] [00036] [00037] [00038] [00039] [00040] [00041] [00042]

[0060] The codes, the categories, and the amounts of the compounds in Example 1, and the properties of a liquid crystal composition prepared from the compounds are summarized in Table 3 below.

TABLE-US-00003 TABLE 3 Code Category Amount (wt %) Properties CC-2D3 Formula III 36 S-N ( C.): 40 CC-3D23 Formula III 8 Cp ( C.): 75 CCP-2D1 Formula IV 13 n: 0.103 CCN-3F Formula IV 8 : 8.2 CCM-2DF Formula IV 10 1 (mPa .Math. s): 63 PMP-2F Formula IV 5 BYQN-3F Formula I 4 BYQN-5O5FA Formula I 6 PMNQN-3F Formula II 5 AMNQN-3F Formula II 5

[0061] The codes, the categories, and the amounts of the compounds in Example 2, and the properties of a liquid crystal composition prepared from the compounds are summarized in Table 4 below.

TABLE-US-00004 TABLE 4 Code Category Amount (wt %) Properties CC-2D3 Formula III 43 S-N ( C.): 40 CC-3D23 Formula III 6 Cp ( C.): 76 PP-41D1 Formula IV 5 n: 0.111 CPP-32 Formula IV 3 : 4.5 PMP-32 Formula IV 4 1 (mPa .Math. s): 45 PMP-33 Formula IV 4 PMP-2F Formula IV 9 PMP-3F Formula IV 3 CPN-3F Formula IV 4 PYQN-3O5FA Formula I 8 APYQN-3F Formula I 6 PMNQN-3F Formula II 3 PMNQN-4F Formula II 2

[0062] The codes, the categories, and the amounts of the compounds in Example 3, and the properties of a liquid crystal composition prepared from the compounds are summarized in Table 5 below.

TABLE-US-00005 TABLE 5 Code Category Amount (wt %) Properties CC-2D3 Formula III 35 S-N ( C.): 40 CC-3D23 Formula III 7 Cp ( C.): 100 CCP-3O1 Formula IV 4 n: 0.110 CCP-2D1 Formula IV 10 : 4.3 CCP-41D1 Formula IV 10 1 (mPa .Math. s): 60 CPP-32 Formula IV 5 CMPC-33 Formula IV 1.5 PMP-2F Formula IV 3.5 PMP-3F Formula IV 4 CMN-5F Formula IV 6 CYQN-3O5FA Formula I 4 BPYQN-4F Formula I 5 PMNQN-3F Formula II 5

[0063] The codes, the categories, and the amounts of the compounds in Example 4, and the properties of a liquid crystal composition prepared from the compounds are summarized in Table 6 below.

TABLE-US-00006 TABLE 6 Code Category Amount (wt %) Properties CC-2D3 Formula III 50 S-N ( C.): 40 CCP-2D3 Formula IV 5 Cp ( C.): 90 CPP-32 Formula IV 4 n: 0.116 PMP-2F Formula IV 3 : 6.6 PMP-3F Formula IV 3 1 (mPa .Math. s): 67 CPTP-32 Formula IV 5 CCPN-3F Formula IV 4 CCPN-5F Formula IV 3 PYQN-3F Formula I 3 AYQN-5F Formula I 4 APYQN-3F Formula I 5 PMNQN-3F Formula II 5 PMNQN-4F Formula II 6

[0064] The codes, the categories, and the amounts of the compounds in Example 5, and the properties of a liquid crystal composition prepared from the compounds are summarized in Table 7 below.

TABLE-US-00007 TABLE 7 Code Category Amount (wt %) Properties CC-2D3 Formula III 42 S-N ( C.): 40 CC-3D23 Formula III 12 Cp ( C.): 80 PP-41D1 Formula IV 6 n: 0.098 CCP-2D1 Formula IV 10 : 2.4 CCP-41D1 Formula IV 6 1 (mPa .Math. s): 45 CPP-32 Formula IV 3 PMP-32 Formula IV 7 PYQN-3F Formula I 8 PMNQN-3F Formula II 3 PMNQN-4F Formula II 3

[0065] The codes, the categories, and the amounts of the compounds in Example 6, and the properties of a liquid crystal composition prepared from the compounds are summarized in Table 8 below.

TABLE-US-00008 TABLE 8 Code Category Amount (wt %) Properties CCP-2D3 Formula III 20 S-N ( C.): 40 CCP-2D1 Formula IV 6 Cp ( C.): 100 CCP-41D1 Formula IV 14 n: 0.086 CCN-3F Formula IV 14 : 9.0 CCN-4F Formula IV 10 1 (mPa .Math. s): 101 CCN-5F Formula IV 10 PMN-5F Formula IV 5 AYQN-3O5FA Formula I 5 BYQN-3F Formula I 5 PYQN-3O5FA Formula I 5 PMNQN-3F Formula II 3 PMNQN-4F Formula II 3

[0066] The codes, the categories, and the amounts of the compounds in Example 7, and the properties of a liquid crystal composition prepared from the compounds are summarized in Table 9 below.

TABLE-US-00009 TABLE 9 Code Category Amount (wt %) Properties CC-2D3 Formula III 33 S-N ( C.): 40 CC-3D23 Formula III 9 Cp ( C.): 92 PP-41D1 Formula IV 2 n: 0.096 CCP-2D1 Formula IV 10 : 4.8 CCP-41D1 Formula IV 10 1 (mPa .Math. s): 60 CCP-32 Formula IV 6 PMP-2F Formula IV 3 PMP-3F Formula IV 3 CCP-3OTF Formula IV 7 CCPM-3F Formula IV 2 BYQN-3O5FA Formula I 4 PYQN-3F Formula I 5 PMNQN-3F Formula II 6

[0067] The codes, the categories, and the amounts of the compounds in Example 8, and the properties of a liquid crystal composition prepared from the compounds are summarized in Table 10 below.

TABLE-US-00010 TABLE 10 Code Category Amount (wt %) Properties CC-2D3 Formula III 34 S-N ( C.): 40 CC-3D23 Formula III 8 Cp ( C.): 96 PP-41D1 Formula IV 2 n: 0.097 CCP-2D1 Formula IV 10 : 5.0 CCP-41D1 Formula IV 10 1 (mPa .Math. s): 65 CCP-32 Formula IV 4 PMP-3F Formula IV 4 CCP-3OTF Formula IV 7 CCPM-5F Formula IV 2 PYQN-3F Formula I 4 PYQN-5O5FA Formula I 4 BPYQN-5F Formula I 2 PMNQN-3F Formula II 4 AMNQN-3F Formula II 5

[0068] The codes, the categories, and the amounts of the compounds in Example 9, and the properties of a liquid crystal composition prepared from the compounds are summarized in Table 11 below.

TABLE-US-00011 TABLE 11 Code Category Amount (wt %) Properties CC-2D3 Formula III 32 S-N ( C.): 40 CC-3D23 Formula III 4 Cp ( C.): 82 PP-41D1 Formula IV 4 n: 0.107 CCP-2D1 Formula IV 10 : 7.5 CCP-41D1 Formula IV 10 1 (mPa .Math. s): 63 PMP-2F Formula IV 3 PMP-3F Formula IV 3 CCP-3OTF Formula IV 7 BYQN-3F Formula I 5 PYQN-3F Formula I 4 PYQN-5O5FA Formula I 4 APYQN-3F Formula I 7 PMNQN-5F Formula II 7

[0069] The codes, the categories, and the amounts of the compounds in Example 10, and the properties of a liquid crystal composition prepared from the compounds are summarized in Table 12 below.

TABLE-US-00012 TABLE 12 Amount Code Category (wt %) Properties CC-2D3 Formula III 35 S-N ( C.): 40 PP-41D1 Formula IV 5 Cp ( C.): 87 CCP-2D1 Formula IV 10 n: 0.098 CCP-41D1 Formula IV 10 : 7.5 PMP-2F Formula IV 3 1 (mPa .Math. s): 65 PMP-3F Formula IV 3 CCP-3OTF Formula IV 6 CCMN-3OTF Formula IV 3 PYQN-3F Formula I 5 PYQN-5F Formula I 5 APYQN-3F Formula I 5 PMNQN-4F Formula II 5 APNQN-3F Formula II 5

[0070] As shown in Examples 1 to 10 above, by introducing functional groups to modify the molecular structures of some of the compounds, the dielectric anisotropy in a direction transverse to a molecular axis is increased and the light transmittance in the IPS-TFT and FFS-TFT mode LCDs is enhanced. Specifically, two hydrogen atoms at two ortho positions of a phenylene group relative to CF.sub.2O in each of Formulae (I) and (II) are substituted with two fluorine atoms. Since it is not necessary to further add liquid crystal having negative dielectric anisotropy into the liquid crystal composition of the disclosure, the ultraviolet stability of the liquid crystal composition of the disclosure is not undesirably reduced. Furthermore, the liquid crystal composition of the disclosure is prepared via specific combination of at least one polar compound of Formula (I), at least one polar compound of Formula (II), at least one compound of Formula (III), and at least one compound of Formula (IV). Since the liquid crystal composition of the disclosure is confirmed to have high clear point, proper birefringence anisotropy, high dielectric anisotropy, low rotational viscosity, and fast response speed, the liquid crystal composition of the disclosure can be applied for active matrix LCDs with a high contrast ratio, such as IPS-TFT and FFS-TFT mode LCDs.

[0071] In the description above, for the purposes of explanation, numerous specific details have been set forth in order to provide a thorough understanding of the embodiment (s). It will be apparent, however, to one skilled in the art, that one or more other embodiments may be practiced without some of these specific details. It should also be appreciated that reference throughout this specification to one embodiment, an embodiment, an embodiment with an indication of an ordinal number and so forth means that a particular feature, structure, or characteristic may be included in the practice of the disclosure. It should be further appreciated that in the description, various features are sometimes grouped together in a single embodiment, figure, or description thereof for the purpose of streamlining the disclosure and aiding in the understanding of various inventive aspects, and that one or more features or specific details from one embodiment may be practiced together with one or more features or specific details from another embodiment, where appropriate, in the practice of the disclosure.

[0072] While the disclosure has been described in connection with what is (are) considered the exemplary embodiment(s), it is understood that this disclosure is not limited to the disclosed embodiment(s) but is intended to cover various arrangements included within the spirit and scope of the broadest interpretation so as to encompass all such modifications and equivalent arrangements.