Polymerizable Liquid Crystal Compound, Liquid Crystal Composition for Optical Element, Polymer, Optically Anisotropic Body, and Optical Element for Display Device

Abstract

A polymerizable liquid crystal compound represented by Chemical Formula 1, a liquid crystal composition for an optical element comprising the same, a polymer polymerized from the same, an optically anisotropic body comprising a cured material or polymerized reactant of the liquid crystal composition or the polymer, and an optical element for a display device comprising the optical anisotropic body are disclosed herein.

Claims

1. A polymerizable liquid crystal compound represented by the following Chemical Formula 1: ##STR00137## wherein, in Chemical Formula 1, Ar1 is a benzene ring group or a cyclohexane group; Y is O, S or NR7; Z is N or CH; A1 to A3 are each O or S; B1 to B3 are each a direct bond, or a substituted or unsubstituted alkylene group; E1 to E3 are each a direct bond, —O—, —COO—, —OOC—, —C.sub.2H.sub.4—, —OCH.sub.2—, or —CH.sub.2O—; R1 to R3 are each a substituted or unsubstituted alkylene group, or a substituted or unsubstituted arylene group; P1 and P2 are each a polymerizable functional group; P3 is hydrogen, a substituted or unsubstituted alkyl group; a substituted or unsubstituted alkoxy group, or a polymerizable functional group; the polymerizable functional group of P1, P2, and P3 is an epoxy group, an oxetane group, an aziridinyl group, a maleimide group, a (meth)acryloyl group, or a (meth)acryloyloxy group; R4 to R7 are each hydrogen, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted alkoxy group; l, m, n, p and q are each an integer of 0 to 3; r is an integer of 0 to 4; when l, m, n, p, q or r is 2 or greater, structures in the parentheses are the same as or different from each other; and L1 to L3 are each a direct bond or represented by the following Chemical Formula 2, ##STR00138## wherein, in Chemical Formula 2, Ar2 is a substituted or unsubstituted arylene group, or a substituted or unsubstituted cycloalkylene group; X is a direct bond, —O—, —(CH.sub.2).sub.aCOO—, —OOC(CH.sub.2).sub.b—, —(CH.sub.2).sub.c—, —O(CH.sub.2).sub.dO—, —(CH.sub.2).sub.e—, —O(CH.sub.2).sub.f—, —CH═CH—, —NHNH—, —CH═N—, —N═CH—, or —C≡C—; a and b are each an integer of 0 to 10; c to f are each an integer of 1 to 10; and t is an integer of 1 to 3, and when t is 2 or greater, structures in the parentheses are the same as or different from each other.

2. The polymerizable liquid crystal compound of claim 1, wherein Chemical Formula 1 is represented by any one of the following Chemical Formulae 1-1 to 1-4: ##STR00139## wherein, in Chemical Formulae 1-1 to 1-4, A1 to A3, B1 to B3, R1 to R3, P1 to P3, L1 to L3, Y, 1, m and n have the same definitions as in Chemical Formula 1.

3. The polymerizable liquid crystal compound of claim 1, wherein Ar2 is an arylene group having 6 to 30 carbon atoms, or a cycloalkylene group having 3 to 30 carbon atoms; and wherein X is —O—, —COO—, —OCH.sub.2O—, —CH.sub.2CH.sub.2—, —CH.sub.2O—, or —OCH.sub.2—.

4. The polymerizable liquid crystal compound of claim 1, wherein L1 and L2 are each represented by the following Chemical Formula 2-1 or 2-2. L3 is a direct bond, and l, m and n are each 1 or 2: ##STR00140## wherein, in Chemical Formulae 2-1 and 2-2, t is an integer of 1 to 3, and when t is 2 or greater, structures in the parentheses are the same as or different from each other.

5. The polymerizable liquid crystal compound of claim 1, which is represented by any one of Chemical Formulae 1-5 to 1-106: ##STR00141## ##STR00142## ##STR00143## ##STR00144## ##STR00145## ##STR00146## ##STR00147## ##STR00148## ##STR00149## ##STR00150## ##STR00151## ##STR00152## ##STR00153## ##STR00154## ##STR00155## ##STR00156## ##STR00157## ##STR00158## ##STR00159## ##STR00160## ##STR00161## ##STR00162## ##STR00163## ##STR00164## ##STR00165## ##STR00166## ##STR00167## ##STR00168## ##STR00169## ##STR00170## ##STR00171## ##STR00172## ##STR00173## ##STR00174## ##STR00175## ##STR00176## ##STR00177## ##STR00178## ##STR00179## ##STR00180## ##STR00181## ##STR00182## ##STR00183## ##STR00184## ##STR00185## ##STR00186## ##STR00187## ##STR00188## ##STR00189## ##STR00190## ##STR00191## ##STR00192## ##STR00193## ##STR00194## ##STR00195## ##STR00196## ##STR00197## ##STR00198## ##STR00199## ##STR00200## ##STR00201## ##STR00202## ##STR00203## ##STR00204## ##STR00205## ##STR00206## ##STR00207## ##STR00208## ##STR00209## ##STR00210## ##STR00211## ##STR00212## ##STR00213## ##STR00214## ##STR00215## ##STR00216## ##STR00217## ##STR00218## ##STR00219## ##STR00220## ##STR00221## ##STR00222## ##STR00223## ##STR00224## ##STR00225## ##STR00226## ##STR00227## ##STR00228## ##STR00229## ##STR00230## ##STR00231## ##STR00232## ##STR00233## ##STR00234## ##STR00235## ##STR00236## ##STR00237## ##STR00238## ##STR00239## ##STR00240## ##STR00241## ##STR00242##

6. A liquid crystal composition for an optical element comprising the polymerizable liquid crystal compound of claim 5.

7. The liquid crystal composition for an optical element of claim 6, further comprising one or more second polymerizable liquid crystal compounds having a different structure from the polymerizable liquid crystal compound.

8. The liquid crystal composition for an optical element of claim 6, further comprising: a polymerization initiator; and a solvent.

9. A polymer obtained by polymerizing a polymerizable liquid crystal compound represented by the following Chemical Formula 1: ##STR00243## wherein, Chemical Formula 1, Ar1 is a benzene ring group or a cyclohexane group; Y is O, S or NR7; Z is N or CH; A1 to A3 are each O or S; B1 to B3 are each a direct bond-,or a substituted or unsubstituted alkylene group; E1 to E3 are each a direct bond, —O—, —COO—, —OOC—, —C.sub.2H.sub.4—, —OCH.sub.2—, or —CH.sub.2O—; R1 to R3 are each a substituted or unsubstituted alkylene group, or a substituted or unsubstituted arylene group; P1 and P2 are each a polymerizable functional group; P3 is hydrogen, a substituted or unsubstituted alkyl group; a substituted or unsubstituted alkoxy group, or a polymerizable functional group; the polymerizable functional group of P1, P2, and P3 is an epoxy group, an oxetane group, an aziridinyl group, a maleimide group, a (meth)acryloyl group or a (meth)acryloyloxy group; R4 to R7 are each hydrogen, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted alkoxy group; l, m, n, p and q are each an integer of 0 to 3; r is an integer of 0 to 4; when l, m, n, p, q or r is 2 or greater, structures in the parentheses are the same as or different from each other; and L1 to L3 are each a direct bond or represented by the following Chemical Formula 2, ##STR00244## wherein, in Chemical Formula 2, Ar2 is a substituted or unsubstituted arylene group, or a substituted or unsubstituted cycloalkylene group; X is a direct bond, —O—, —(CH.sub.2).sub.aCOO—, —OOC(CH.sub.2).sub.b—, —(CH.sub.2).sub.c—, —O(CH.sub.2).sub.dO—, —(CH.sub.2).sub.e—, —O(CH.sub.2).sub.f—, —CH═CH—, —NHNH—, —CH═N—, —N═CH—, or —C≡C—; a and b are each an integer of 0 to 10; c to f are each an integer of 1 to 10; and t is an integer of 1 to 3, and when t is 2 or greater, structures in the parentheses are the same as or different from each other.

10. The polymer of claim 9, obtained by further copolymerizing with one or more second polymerizable liquid crystal compounds having a different structure than the polymerizable liquid crystal compound.

11. An optically anisotropic body comprising a cured material or a polymerized reactant of the liquid crystal composition of claim 6.

12. An optically anisotropic body comprising the polymer of claim 9.

13. An optical element for a display device comprising the optically anisotropic body of claim 11.

14. An optical element for a display device comprising the optically anisotropic body of claim 12.

Description

EXAMPLE: PREPARATION OF RETARDATION LAYER

Example 1

[0224] (1) Preparation of Liquid Crystal Composition

[0225] A liquid crystal composition was prepared by mixing 0.517 g of polymerizable Compound 1-6 synthesized using the method of Preparation Example 1, 0.221 g of polymerizable Compound 1-15 synthesized in Preparation Example 2, 0.00716 g of OXE-1 (manufactured by Ciba Specialty Chemicals Inc.), a polymerization initiator, 0.00113 g of p-methoxyphenol (MEHQ), a polymerization inhibitor, 0.0150 g of BYK-3550 (manufactured by BYK Chemie Japan KK), a surfactant, and 2.25 g of cyclohexanone, a solvent.

[0226] (2) Preparation of Retardation Layer

[0227] The liquid crystal composition was coated on a triacetylcellulose (TAC) substrate so that the thickness after drying is approximately from 1 μm to 2 μm, and after removing the solvent, ultraviolet rays having a wavelength in a UVB region (approximately 300 nm) were irradiated at a total dose of approximately 200 mJ/cm.sup.2 for curing while being aligned on the xy plane, and a retardation layer was prepared. The dose was measured using a UV power puck II.

Example 2 to Example 5

[0228] Liquid crystal compositions and retardation layers were prepared in the same manner as in Example 1 except that the liquid crystal compositions were each prepared using a polymerizable compound, a polymerization initiator, a polymerization inhibitor, a surfactant and a solvent with the material and in the content described in the following Table 1.

TABLE-US-00001 TABLE 1 Name Name and Name and Name and and Content of Content of Content of Content Name and Polymerizable Polymerization Polymerization of Content of Compound Initiator Inhibitor Surfactant Solvent Example Compound OXE-1 MEHQ BYK-3550 Cyclohexanone 2 1-23 0.00716 g 0.00113 g 0.0150 g 2.25 g 0.517 g Compound 1-24 0.221 g Example Compound OXE-1 MEHQ BYK-3550 Cyclohexanone 3 1-30 0.00573 g 0.000905 g 0.0150 g 2.40 g 0.517 g Compound 1-31 0.221 g Example Compound OXE-1 MEHQ BYK-3550 Cyclohexanone 4 1-28 0.00716 g 0.00113 g 0.0150 g 2.25 g 0.738 g Example Compound OXE-1 MEHQ BYK-3550 Cyclohexanone 5 1-38 0.00573 g 0.000905 g 0.0150 g 2.40 g 0.590 g

Comparative Example 1

[0229] A retardation layer was prepared in the same manner as in Example 1 except that the following Comparative Compound A was used instead of polymerizable Compounds 1-6 and 1-15.

[0230] [Comparative Compound A]

##STR00134##

Comparative Example 2

[0231] A retardation layer was prepared in the same manner as in Example 1 except that the following Comparative Compound B was used instead of polymerizable Compounds 1-6 and 1-15.

[0232] Compound B was synthesized in the same manner as in Korean Patent Application Laid-Open Publication No. 2017-0074178.

[0233] [Comparative Compound B]

##STR00135##

Comparative Example 3

[0234] A retardation layer was prepared in the same manner as in Example 1 except that the following Comparative Compound C was used instead of polymerizable Compounds 1-6 and 1-15.

[0235] Compound C was synthesized in the same manner as in Korean Patent Application Laid-Open Publication No. 2017-0086047.

[0236] [Comparative Compound C]

##STR00136##

Experimental Example: Evaluation on Retardation Layer Properties

[0237] Properties of the retardation layers prepared in Examples 1 to 5, and Comparative Examples 1 to 3 were measured using methods as follows, and the results are shown in the following [Table 2].

[0238] (1) Evaluation on Retardation Value

[0239] Retardation in a plane or thickness direction was measured using an Axoscan (Axomatrics, Inc.) capable of extracting a Mueller matrix. Measurements were made for each of light having a wavelength of 450 nm, 550 nm and 650 nm, retardation was extracted by obtaining 16 Mueller matrix values according to the manufacturer's manual, and these values were evaluated as follows.

[0240] A: R(450)/R(550)<0.85

[0241] B: 0.85<R(450)/R(550)<0.90

[0242] C: 0.90<R(450)/R(550)<0.95

[0243] D: 0.95<R(450)/R(550)<1.00

[0244] E: 1.00<R(450)/R(550)

[0245] (2) Measurement of Retardation Layer Thickness

[0246] Thicknesses of the thin films were measured using a Bruker DektakXT (Bruker Corporation) capable of measuring a thin film level difference.

[0247] (3) Evaluation on High Temperature Durability

[0248] An initial retardation value (Re.sub.in) of the prepared retardation layer was measured at 25° C., and after measuring a retardation value (Re.sub.f) after heating for 96 hours at 80° C., a retardation change rate (ΔRe) was calculated according to the following [Equation 1].

ΔRe=(1−Re.sub.f/Re.sub.in)×100  [Equation 1]

After that, the results were evaluated in 4 steps as follows according to the magnitude of the ΔRe value.

[0249] A: ΔRe<0.5

[0250] B: 0.5<ΔRe<1.0

[0251] C: 1.0<ΔRe<5.0

[0252] D: 5.0<ΔRe

TABLE-US-00002 TABLE 2 High Film Retardation Temperature Alignment Thickness Value Durability Defects (μm) Evaluation Evaluation Example 1 No 1.5 B A Example 2 No 1.3 A A Example 3 No 1.7 A A Example 4 No 1.6 A A Example 5 No 1.8 B B Comparative No 1.6 E A Example 1 Comparative No 1.6 D C Example 2 Comparative No 1.3 B D Example 3

[0253] As identified from the experimental results, a retardation film without defects may be prepared and high temperature durability may be enhanced as well when using the polymerizable compound of the present disclosure. It was identified that, whereas Comparative Examples 1 and 2 showed flat dispersibility, Examples 1 to 5 using the polymerizable compound of the present disclosure had excellent reverse dispersibility and thereby had excellent optical properties. Although Comparative Example 3 had similar optical properties to Examples 1 and 5, the performance was significantly low in terms of high temperature durability compared to the examples of the present application. It was identified that, in the polymerizable compound of the present disclosure, the structural skeleton to exhibit reverse dispersibility has a thermally stable structure, and therefore, changes in the retardation value were small at a high temperature.