Liquid crystal composition and use thereof

Abstract

A liquid crystal composition contains: at least one compound of general formula I and at least one polymerizable compound of general formula II. Such a liquid crystal composition has a suitable optical anisotropy, a suitable dielectric anisotropy, and a better pretilt angle consistency while maintaining a relatively high clearing point, and the drop mura is good. When the liquid crystal composition is applied to a PSA liquid crystal display, the liquid crystal composition has an excellent display effect. ##STR00001##

Claims

1. A liquid crystal composition, wherein the liquid crystal composition comprises: (i) at least one compound selected from a group consisting of the following compounds ##STR00102##  and combinations thereof; in which R.sub.11 represents —H, —F, C.sub.1-7 alkyl or alkoxy, C.sub.2-7 alkenyl or alkenoxy, —OR.sub.51OR.sub.61, ##STR00103##  wherein one or more H on the alkyl or alkoxy and the alkenyl or alkenoxy can be substituted by F, R.sub.21 is —OR.sub.51OR.sub.61; wherein R.sub.51 represents C.sub.3-12 alkyl or C.sub.3-12 alkenyl and R.sub.61 represents a linear C.sub.1-10 alkyl or C.sub.2-10 alkenyl; (ii) at least one polymerizable compound of general formula II ##STR00104## in which, P.sub.1 and P.sub.2 each independently represents ##STR00105##  or —SH; r.sub.1 represents 1, 2 or 3; r.sub.2 and r.sub.3 each independently represents a positive integer of 0˜6; r.sub.4 and r.sub.5 each independently represents 0, 1, 2, 3 or 4; Z.sub.2 represents single bond, —CH.sub.2CH.sub.2—, —COO—, —OCO—, —CH.sub.2O—, —OCH.sub.2— or —CH═CH—COO—; Z.sub.p1 and Z.sub.p2 are same or different and each independently selected from a group consisting of single bond, —O—, —S—, —NH—, —NHCOO—, —OCONH—, —CF.sub.2O—, —OCF.sub.2—, —CF.sub.2S—, —SCF.sub.2—, —CH.sub.2CH.sub.2—, —CF.sub.2CH.sub.2—, —CH.sub.2CF.sub.2—, —CF.sub.2CF.sub.2—, —CF═CH—, —CH═CF—, —CF═CF—, —CO—, —COO—, —OCO—, —OCOO—, —CH.sub.2—, —OCH.sub.2—, —SCH.sub.2—, —CH.sub.2S—, —CH═CH—, —C≡C—, —CH═CH—COO— and —OCO—CH═CH—; Y.sub.1 and Y.sub.2 each independently represents H, halogen, C.sub.1-3 alkyl or alkoxy, provided that if Z.sub.p1 or Z.sub.p2 is a single bond, then either Y.sub.1 or Y.sub.2 is halogen or r.sub.1 is 2 or 3; (iii) at least one compound of general formula III ##STR00106## R.sub.3 and R.sub.4 each independently represents —H, —F, C.sub.1-12 alkyl or alkoxy, C.sub.2-12 alkenyl or alkenoxy, ##STR00107##  wherein one or more H on the alkyl or alkoxy and the alkenyl or alkenoxy can be substituted by F; Z.sub.3 represents single bond, —COO—, —OCO—, —CH.sub.2O—, —OCH.sub.2— or —CH.sub.2CH.sub.2—; L.sub.3 and L.sub.4 each independently represents —F, —Cl, —CN or —NCS; ring ##STR00108##  represents ##STR00109##  wherein one or more —CH.sub.2— in ##STR00110##  can be replaced by —O—, one or more H on ##STR00111##  can be substituted by halogen; n1 represent 0, 1, 2 or 3, and when n1 is 2 or 3, ring ##STR00112##  can be same or different, Z.sub.3 can be same or different; n2 represent 0 or 1; and (iv) at least one compound of general formula IV ##STR00113## in which, R.sub.7 and R.sub.8 each independently represents H, C.sub.1-12 alkyl or alkoxy, or C.sub.2-12 alkenyl or alkenoxy; ring ##STR00114##  and ring ##STR00115##  each independently represents ##STR00116## r represents 1, 2 or 3; wherein the compound of formula I-3, I-4, and/or I-9 provides 1 to 30% by weight of the total amount of the liquid crystal composition, the compound of general formula II provides 0.001 to 5% by weight of the total amount of the liquid crystal composition, the compound of general formula III provides up to 70% by weight of the total amount of the liquid crystal composition, and the compound of general formula IV provides up to 70% by weight of the total amount of the liquid crystal composition.

2. The liquid crystal composition according to claim 1, further comprising compounds selected from a group consisting of the following compounds: ##STR00117## ##STR00118## in which, R.sub.11 represents —H, —F, C.sub.1-7 alkyl or alkoxy, C.sub.2-7 alkenyl or alkenoxy, —OR.sub.51OR.sub.61; ##STR00119##  wherein one or more H on the alkyl or alkoxy and the alkenyl or alkenoxy can be substituted by F, and R.sub.21 is —OR.sub.51OR.sub.61; R.sub.51 represents C.sub.3-12 alkyl or C.sub.3-12 alkenyl and R.sub.61 represents a linear C.sub.1-10 alkyl or C.sub.2-10 alkenyl.

3. The liquid crystal composition according to claim 1, wherein P.sub.1 and P.sub.2 in the general formula II each independently represents ##STR00120##

4. The liquid crystal composition according to claim 3, wherein the compound of general formula II is selected from a group consisting of the following compounds: ##STR00121## ##STR00122## ##STR00123## ##STR00124## ##STR00125## ##STR00126## ##STR00127##

5. The liquid crystal composition according to claim 1, wherein the compound of general formula IV is selected from a group consisting of the following compounds: ##STR00128## in which, R.sub.71 and R.sub.81 each independently represents H, C.sub.1-7 alkyl or alkoxy, or C.sub.2-7 alkenyl or alkenoxy.

6. A liquid crystal display device comprising the liquid crystal composition of claim 1.

7. A PSA liquid crystal display device comprising the liquid crystal composition of claim 6.

8. The liquid crystal display device according to claim 6, wherein the composition provides for pretilt angle uniformity and drop mura performance with drop mura not being observable using a light shielding plate having a transmittance of 2% under 48 gray scales.

Description

DETAILED EMBODIMENTS

(1) The present invention will be illustrated by combining the detailed embodiments below. It should be noted that, the following examples are exemplary embodiments of the present invention, which are only used to illustrate the present invention, not to limit it. Other combinations and various modifications within the conception of the present invention are possible without departing from the subject matter and scope of the present invention.

(2) For the convenience of the expression, the group structures of the liquid crystal compositions in the following Examples are represented by the codes listed in Table 1:

(3) TABLE-US-00001 TABLE 1 Codes of the group structures of liquid crystal compounds Unit structure of group Code Name of group C 1,4-cyclohexylidene P 1,4-phenylene G 2-fluoro-1,4-phenylene U 2,5-difluoro-1,4-phenylene W 2,3-difluoro-1,4-phenylene I indan-2,5-diyl —CH.sub.2CH.sub.2— 2 ethyl bridge bond —OCF.sub.3 OCF3 trifluoromethoxy —F F fluorine substituent —O— O oxygen substituent —CF.sub.2O— 1(2F)O difluoro ether group —COO— E ester bridge bond —C.sub.nH.sub.2n+1 or —C.sub.mH.sub.2m+1 n or m alkyl —CH═CH— or —CH═CH.sub.2 V alkenyl

(4) Take a compound with the following structural formula as an example:

(5) ##STR00099##

(6) Represented by the codes listed in Table 1, this structural formula can be expressed as nCCGF, in which, n in the code represents the number of the carbon atoms of the alkyl on the left, for example, n is “3”, meaning that the alkyl is —C.sub.3H.sub.7; C in the code represents cyclohexyl, G represents 2-fluoro-1,4-phenylene, and F represents fluoro.

(7) The abbreviated codes of the test items in the following Examples are as follows: Cp (° C.) clearing point (nematic-isotropy phases transition temperature) Δn optical anisotropy (589 nm, 25° C.) Δε dielectric anisotropy (1 KHz, 25° C.)

(8) In which,

(9) the optical anisotropy is tested and obtained by using abbe refractometer under sodium lamp (589 nm) light source at 25° C.;

(10) Δε=ε∥—ε⊥, in which, ε.sub.1 is a dielectric constant parallel to the molecular axis, ε⊥ is a dielectric constant perpendicular to the molecular axis, with the test conditions: 25° C., 1 KHz, TN90 type test cell with a cell gap of 7 μm.

(11) Drop mura test: The uniformity of the liquid crystal panel is observed using a light shielding plate having a transmittance of 8%, 4% and 2%, respectively, under 48 gray scales. If the drop mura is observed, it is marked as “Yes”; if the drop mura is not observed, it is marked as “No”. The easness of the observation of drop mura for light shielding plates with different transmittances can be ranked as 8%>4%>2%.

(12) The ingredients used in the following Examples can be synthesized by well-known methods or obtained by commercial means. These synthetic techniques are routine, and the test results show that the liquid crystal compounds thus prepared meet the criteria for the electronic compounds.

(13) Several liquid crystal compositions are prepared according to the formulations of the liquid crystal compositions specified in the following Examples. The preparation of the liquid crystal compositions is proceeded according to the conventional methods in the art, and as an example, the compositions are prepared by mixing the specified formulation via the processing modes, such as heating, ultrasonic processing, suspending processing and so forth.

(14) The liquid crystal compositions specified in the following Examples are prepared and studied. The formulas of the liquid crystal compositions and their test results for the performance are shown below.

Comparative Example 1

(15) The liquid crystal composition of Comparative Example 1 is prepared according to each compound and weight percentage listed in Table 2 and is tested by filling the same between two substrates of a liquid crystal display device.

(16) TABLE-US-00002 TABLE 2 Formulation of liquid crystal composition Component code Weight percent 3CWO2 6 5CWO2 8 2CPWO2 7 3CPWO4 9 3CWO4 7 3CCWO2 14 4CCWO2 5 3CPO2 9 3CPP2 6 3CC2 20 4CC3 9 Total 100

(17) The polymerizable component in Table 3 is added to 100 parts by weight of the above liquid crystal composition.

(18) TABLE-US-00003 TABLE 3 Polymerizable component Structural formula Part 00 0.3

(19) The test results of performance parameters of the resulting composition are shown in Table 4 below.

(20) TABLE-US-00004 TABLE 4 Tests of performance parameters Δn 0.094 Δε −3.1 Cp 73.7 Drop mura Observation (8%) Yes Drop mura Observation (4%) Yes Drop mura Observation (2%) Yes

Example 1

(21) The liquid crystal composition of Example 1 as shown in Table 5 is prepared by replacing 3CWO2 in Comparative Example 1 with 3CWO4O1 and is tested by filling the same between two substrates of a liquid crystal display device.

(22) TABLE-US-00005 TABLE 5 Formulation of liquid crystal composition Component Weight code percent 3CWO4O1 6 5CWO2 8 2CPWO2 7 3CPWO4 9 3CWO4 7 3CCWO2 14 4CCWO2 5 3CPO2 9 3CPP2 6 3CC2 20 4CC3 9 Total 100

(23) The content and component of the polymerizable component are same as those of Comparative Example 1.

(24) The test results of performance parameters of the resulting composition are shown in Table 6 below.

(25) TABLE-US-00006 TABLE 6 Tests of performance parameters Δn 0.093 Δε −3.0 Cp 72.6 Drop mura Observation (8%) Yes Drop mura Observation (4%) Yes Drop mura Observation (2%) No

Example 2

(26) The liquid crystal composition of Example 2 as shown in Table 7 is prepared by replacing 4CCWO2 in Comparative Example 1 with 1O3OCCWO2 and is tested by filling the same between two substrates of a liquid crystal display device.

(27) TABLE-US-00007 TABLE 7 Formulation of liquid crystal composition Component Weight code percent 3CWO2 6 5CWO2 8 2CPWO2 7 3CPWO4 9 3CWO4 7 3CCWO2 14 1O3OCCWO2 5 3CPO2 9 3CPP2 6 3CC2 20 4CC3 9 Total 100

(28) The content and component of the polymerizable component are same as those of Comparative Example 1.

(29) The test results of performance parameters of the resulting composition are shown in Table 8 below.

(30) TABLE-US-00008 TABLE 8 Tests of performance parameters Δn 0.093 Δε −3.1 Cp 73.5 Drop mura Observation (8%) Yes Drop mura Observation (4%) Yes Drop mura Observation (2%) No

Example 3

(31) The liquid crystal composition of Example 3 as shown in Table 9 is prepared by replacing 3CWO2 and 4CCWO2 in Comparative Example 1 with 3CWO4O1 and 1O3OCCWO2 respectively and is tested by filling the same between two substrates of a liquid crystal display device.

(32) TABLE-US-00009 TABLE 9 Formulation of liquid crystal composition Component Weight code percent 3CWO4O1 6 5CWO2 8 2CPWO2 7 3CPWO4 9 3CWO4 7 3CCWO2 14 1O3OCCWO2 5 3CPO2 9 3CPP2 6 3CC2 20 4CC3 9 Total 100

(33) The content and component of the polymerizable component are same as those of Comparative Example 1.

(34) The test results of performance parameters of the resulting composition are shown in Table 10 below.

(35) TABLE-US-00010 TABLE 10 Tests of performance parameters Δn 0.094 Δε −3.1 Cp 73.7 Drop mura Observation (8%) Yes Drop mura Observation (4%) No Drop mura Observation (2%) No

(36) It is clear from the comparison of the above Comparative Example 1 and Examples 1-3 that the liquid crystal composition comprising the compound(s) of general formula I of the present invention has a more excellent performance in drop mura.

Comparative Example 2

(37) The liquid crystal composition of Comparative Example 2 is prepared according to each compound and weight percentage listed in Table 11 and is tested by filling the same between two substrates of a liquid crystal display device.

(38) TABLE-US-00011 TABLE 11 Formulation of liquid crystal composition Component Weight code percent 3CC2 23 4CC3 3 5PP1 11 3PWO2 10 5CC3 4 3C1OWO2 4 3CCP1 3 3CPP2 15 3CPWO2 9 2CC1OWO2 7 3CC1OWO2 11 Total 100

(39) The polymerizable component in Table 12 is added to 100 parts by weight of the above liquid crystal composition.

(40) TABLE-US-00012 TABLE 12 Polymerizable component Structural formula Part 01 0.35

(41) The test results of performance parameters of the resulting composition are shown in Table 13 below.

(42) TABLE-US-00013 TABLE 13 Tests of performance parameters Δn 0.109 Δε −3.2 Cp 75.6 Drop mura Observation (8%) Yes Drop mura Observation (4%) Yes Drop mura Observation (2%) No

Example 4

(43) The liquid crystal composition of Example 4 as shown in Table 14 is prepared by replacing 3PWO2 and 3C1OWO2 in Comparative Example 2 with 3PWO3O1 and 3C1OWO4O1 respectively and is tested by filling the same between two substrates of a liquid crystal display device.

(44) TABLE-US-00014 TABLE 14 Formulation of liquid crystal composition Component Weight code percent 3CC2 23 4CC3 3 5PP1 11 3PWO3O1 10 5CC3 4 3C1OWO4O1 4 3CCP1 3 3CPP2 15 3CPWO2 9 2CC1OWO2 7 3CC1OWO2 11 Total 100

(45) The content and component of the polymerizable component are same as those of Comparative Example 2.

(46) The test results of performance parameters of the resulting composition are shown in Table 15 below.

(47) TABLE-US-00015 TABLE 15 Tests of performance parameters Δn 0.109 Δε −3.2 Cp 75.6 Drop mura Observation (8%) No Drop mura Observation (4%) No Drop mura Observation (2%) No

Example 5

(48) The liquid crystal composition of Example 5 as shown in Table 16 is prepared by replacing 3CPWO2 in Comparative Example 2 with 3CPWO3O1 and is tested by filling the same between two substrates of a liquid crystal display device.

(49) TABLE-US-00016 TABLE 16 Formulation of liquid crystal composition Component Weight code percent 3CC2 23 4CC3 3 5PP1 11 3PWO2 10 5CC3 4 3C1OWO2 4 3CCP1 3 3CPP2 15 3CPWO3O1 9 2CC1OWO2 7 3CC1OWO2 11 Total 100

(50) The content and component of the polymerizable component are same as those of Example 1.

(51) The test results of performance parameters of the resulting composition are shown in Table 17 below.

(52) TABLE-US-00017 TABLE 17 Tests of performance parameters Δn 0.1085 Δε −3.2 Cp 74.2 Drop mura Observation (8%) No Drop mura Observation (4%) No Drop mura Observation (2%) No

Example 6

(53) The liquid crystal composition of Example 6 as shown in Table 18 is prepared by replacing 3C1OWO2 and 3CPWO2 in Comparative Example 2 with 3C1OWO4O1 and 3CPWO3O1 respectively and is tested by filling the same between two substrates of a liquid crystal display device.

(54) TABLE-US-00018 TABLE 18 Formulation of liquid crystal composition Component Weight code percent 3CC2 23 4CC3 3 5PP1 11 3PWO2 10 5CC3 4 3C1OWO4O1 4 3CCP1 3 3CPP2 15 3CPWO3O1 9 2CC1OWO2 7 3CC1OWO2 11 Total 100

(55) The content and component of the polymerizable component are same as those of Example 1.

(56) The test results of performance parameters of the resulting composition are shown in Table 19 below.

(57) TABLE-US-00019 TABLE 19 Tests of performance parameters Δn 0.107 Δε −3.0 Cp 73.9 Drop mura Observation (8%) No Drop mura Observation (4%) No Drop mura Observation (2%) No

(58) It is clear from the comparison of the above Comparative Example 2 and Examples 4-6 that the liquid crystal composition comprising the compound(s) of general formula I of the present invention has a more excellent performance in drop mura.

(59) The above embodiments are merely illustrative of the technical concepts and features of the present invention, and provided for facilitating the understanding and practice of the present invention by those skilled in the art. However, the protection scope of the invention is not limited thereto. Equivalent variations or modifications made without departing from the spirit and essence of the present invention are intended to be contemplated within the protection scope of the present invention.

INDUSTRIAL APPLICABILITY

(60) The liquid crystal compositions related in the present invention can be applied to the field of liquid crystal.