TWI518174B - Liquid crystal medium and liquid crystal display apparatus - Google Patents

Description

Liquid crystal medium and liquid crystal display device

The present invention relates to a display medium and a display device, and more particularly to a liquid crystal medium and a liquid crystal display device.

Liquid crystal display (LCD) is a display that utilizes liquid crystal photoelectric change, and has the advantages of small size, light weight, low power consumption, and good display quality. Therefore, it has become the mainstream of flat panel display in recent years. With the advancement of technology, the industry is constantly using various methods to improve the color saturation of liquid crystal displays to meet the needs of users.

For liquid crystal materials in liquid crystal displays, liquid crystal media having high thermal stability, high clearing point, good dielectric properties (Δε), and good birefringence (Δn) are in line with current needs. In particular, when the liquid crystal medium has high thermal stability and a high clearing point, the liquid crystal display device can have better display performance. At the same time, when the liquid crystal medium has good dielectric properties, the liquid crystal display device can be driven to have a lower drive. Voltage to achieve power saving purposes. When the liquid crystal medium has a high birefringence, the liquid crystal display device can have a good display quality.

The present invention provides a liquid crystal medium having high thermal stability, good dielectric properties, and high birefringence.

The present invention provides a liquid crystal display device having a low driving voltage and good display quality.

The present invention provides a liquid crystal medium comprising a first component and a second component. The first component is at least one compound selected from the group consisting of compounds represented by formula (I) to formula (II). The second component is a compound represented by the formula (III).

R _{1 is} selected from the group consisting of H, C ₁ -C ₁₀ alkyl and C ₂ -C ₁₀ alkenyl, one or more of C ₁ -C ₁₀ alkyl and C ₂ -C ₁₀ alkenyl but mutual The discontinuous -CH ₂ - may be substituted by -O-, -CO-, -COO- or -OCO-, and the C ₁ -C ₁₀ alkyl group and the H on the C ₂ -C ₁₀ alkenyl group may be substituted by F; ₁ to A ₄ are each independently selected from 1,4-phenylene, 1,4-cyclohexylene, 2,5-tetrahydropyranyl (2) , 5-tetrahydropyranylene) and a group consisting of indane-2,5-diyl, at least one of A ₁ ~A ₄ is indane-2,5-diyl, 1,4 - H on the phenyl and indan-2,5-diyl groups may be substituted by F or CH ₃ ; Z ₁ to Z ₃ are each independently selected from the group consisting of a single bond, -CH ₂ -CH ₂ -, -CH=CH- H, -COO-, -OCO-, -CF ₂ O- or -OCF ₂ -, -CH ₂ -CH ₂ - and -CH=CH- may be substituted by F; m, n, o and p are each independent It is an integer from 0 to 2 and is not 0 at the same time.

R _{2 is} selected from the group consisting of H, C ₁ -C ₁₅ alkyl and C ₂ -C ₁₅ alkenyl, wherein one or more of C ₁ -C ₁₅ alkyl and C ₂ -C ₁₅ alkenyl but The mutually discontinuous -CH ₂ - may be substituted by -O-, -CO-, -COO- or -OCO-, the C ₁ -C ₁₅ alkyl group and the H on the C ₂ -C ₁₅ alkenyl group may be F or CH ₃ substituted; X ₁ is F, Cl, CF ₃ or OCF ₃ ; A ₅ ~ A ₇ are each independently selected from 1,4-phenylene, 1,4-cyclohexylene, 2,5-extended tetrahydropyran a group consisting of a base and a full-2,5-diyl group, at least one of A ₅ ~A ₇ is indole-2,5-diyl, A ₈ is 1,4-phenylene, 1,4-extension H on phenyl and indan-2,5-diyl may be substituted by F; L is -CF ₂ O-; t is 1, q, r and s are each independently an integer from 0 to 3 and q+r+ s≧3.

R ₃ and R ₄ are each independently selected from the group consisting of F, C ₁ -C ₁₅ alkyl and C ₂ -C ₁₅ alkenyl, wherein C ₁ -C ₁₅ alkyl and one on C ₂ -C ₁₅ alkenyl Or two or more but mutually discontinuous -CH ₂ - may be substituted by -O-, -CO-, -COO- or -OCO-, C ₁ -C ₁₅ alkyl group and H on C ₂ -C ₁₅ alkenyl group It may be substituted by F or CH ₃ ; A ₉ ~ A ₁₂ are each independently selected from 1,4-phenylene, 1,4-cyclohexylene, 2,5-tetrahydropyranyl and indole-2,5 a group consisting of a dibasic group, and any H in the group may be substituted by F; Z ₄ to Z ₅ are each independently selected from a single bond, -CH ₂ -CH ₂ -, -CH=CH-, -C≡C -, -COO-, -OCO- or -CO-, and at least one of Z ₄ -Z _{5 is} -C≡C-, -CH ₂ -CH ₂ - and H on -CH=CH- may be substituted by F; f and g are each independently an integer of 0 to 2 and are not 0 at the same time.

Further, the present invention further proposes a liquid crystal display device. The liquid crystal display device includes a liquid crystal medium as described above.

Based on the above, the liquid crystal medium of the present invention includes the first component and the second component, and thus has high thermal stability, good dielectric properties, and high birefringence. Further, the liquid crystal display device of the present invention includes the above liquid crystal medium, and thus has good display quality and low driving voltage.

The above described features and advantages of the invention will be apparent from the following description.

As used herein, a single functional group embraces an unsubstituted functional group as well as a substituted functional group, while a single group is represented by an unsubstituted group as well as a substituted group. Taking 1,4-phenylene as an example, it contains an unsubstituted 1,4-phenylene group and a substituted 1,4-phenylene group. Other single functional groups or single groups are represented by this, which are well known to those skilled in the art and will not be further described herein.

The invention provides a liquid crystal medium which has high thermal stability and good Dielectric properties and high birefringence, so when the liquid crystal display device employs the liquid crystal medium, the liquid crystal display device can have good display quality and has a low driving voltage.

The liquid crystal medium of the present invention includes a first component and a second component. The first component is at least one compound selected from the group consisting of compounds represented by formula (I) to formula (II). The second component is a compound represented by the formula (III).

The compound represented by the formula (I) of the present example is as follows: R _{1 is} selected from the group consisting of H, C ₁ -C ₁₀ alkyl and C ₂ -C ₁₀ alkenyl, wherein C ₁ -C ₁₀ alkyl and one -CH ₂ - on C ₂ -C ₁₀ alkenyl may Substituted by -O-, -CO-, -COO- or -OCO-, or two or more but mutually discontinuous -CH ₂ - groups on a C ₁ -C ₁₀ alkyl group and a C ₂ -C ₁₀ alkenyl group -O-, -CO-, -COO- or -OCO- substitution. The C ₁ -C ₁₀ alkyl group and the H on the C ₂ -C ₁₀ alkenyl group may be substituted by F. A ₁ to A ₄ are each independently selected from 1,4-phenylene, 1,4-cyclohexylene, 2,5-tetrahydropyranyl ( 2,5-tetrahydropyranylene) and a group consisting of indane-2,5-diyl, wherein at least one of A ₁ ~A ₄ is indole-2,5-diyl, 1 , 4-phenylene, and H of indan-2,5-diyl group may be substituted with F or CH _3. Z ₁ ~ Z ₃ are each independently selected from a single _{bond, -CH 2 -CH 2 -, -} CH = CH -, - COO -, - OCO -, - CF 2 O- or -OCF ₂ -, wherein -CH ₂ - H on CH ₂ - and -CH=CH- may be substituted by F. m, n, o, and p are each independently an integer of 0 to 2 and are not 0 at the same time.

The compound represented by the formula (II) of the present example is as follows: R _{2 is} selected from the group consisting of H, C ₁ -C ₁₅ alkyl and C ₂ -C ₁₅ alkenyl, wherein C ₁ -C ₁₅ alkyl and one -CH ₂ - on C ₂ -C ₁₅ alkenyl may Substituted by -O-, -CO-, -COO- or -OCO-, or two or more but mutually discontinuous -CH ₂ - groups on a C ₁ -C ₁₅ alkyl group and a C ₂ -C ₁₅ alkenyl group -O-, -CO-, -COO- or -OCO- substitution. The C ₁ -C ₁₅ alkyl group and the H on the C ₂ -C ₁₅ alkenyl group may be substituted by F or CH ₃ . X ₁ is F, Cl, CF ₃ or OCF ₃ . A ₅ to A ₇ are each independently selected from the group consisting of 1,4-phenylene, 1,4-cyclohexylene, 2,5-tetrahydropyranyl and indane-2,5-diyl. a ₅ ~ a ₇ wherein at least one of indan-2,5-diyl, a ₈ is 1,4-phenylene, 1,4-phenylene, and H of indan-2,5-diyl Can be replaced by F. L is -CF ₂ O-. t is 1, q, r, and s are each independently an integer of 0 to 3 and q+r+s≧3.

The compound represented by the formula (III) of the present example is as follows: R ₃ and R ₄ are each independently selected from the group consisting of F, C ₁ -C ₁₅ alkyl and C ₂ -C ₁₅ alkenyl, wherein C ₁ -C ₁₅ alkyl and one on C ₂ -C ₁₅ alkenyl -CH ₂ - may be substituted by -O-, -CO-, -COO- or -OCO-, or two or more of C ₁ -C ₁₅ alkyl groups and C ₂ -C ₁₅ alkenyl groups - CH ₂ - may be substituted by -O-, -CO-, -COO- or -OCO-. The C ₁ -C ₁₅ alkyl group and the H on the C ₂ -C ₁₅ alkenyl group may be substituted by F or CH ₃ . A ₉ to A ₁₂ are each independently selected from the group consisting of 1,4-phenylene, 1,4-cyclohexylene, 2,5-tetrahydropyranyl and indane-2,5-diyl. And any H in this group can be replaced by F. Z ₄ to Z ₅ are each independently selected from a single bond, -CH ₂ -CH ₂ -, -CH=CH-, -C≡C-, -COO-, -OCO- or -CO-, and Z ₄ ~Z ₅ at least one _{-C≡C -, - CH 2 -CH 2} - and -CH H on = CH- may be substituted with F. f and g are each independently an integer of 0 to 2 and are not 0 at the same time.

Specifically, the compound represented by the formula (III) is a compound having a -C≡C- structure. When the liquid crystal medium includes the compound represented by the formula (III), the liquid crystal medium can be made to have good dielectric characteristics, high birefringence, and appropriate viscosity.

In the present embodiment, the content of the first component is 5 wt% to 50 wt%, and the content of the second component is 10 wt% to 25 wt%, based on the total weight of the liquid crystal medium.

In the present embodiment, the liquid crystal medium may be a compound represented by the formula (I) and a compound represented by the formula (III), and does not include the compound represented by the formula (II). Alternatively, the liquid crystal medium may include a compound represented by the formula (II) and a compound represented by the formula (III), and does not include the compound represented by the formula (I). However, the present invention is not limited thereto, and in other embodiments, the first component of the liquid crystal medium includes both the compound represented by the formula (I) and the compound represented by the formula (II). In other words, the liquid crystal medium may include both the compound represented by the formula (I), the compound represented by the formula (II), and the compound represented by the formula (III). When the liquid crystal medium includes the first component and the second component, the liquid crystal medium has high thermal stability, good dielectric properties, high birefringence, and appropriate viscosity.

Further, the compound represented by the formula (I) may include the following structure: L ₁ ~ L ₆ may be H, F, CH ₃ ; R _{1 is} selected from the group consisting of H, C ₁ -C ₁₀ alkyl and C ₂ -C ₁₀ alkenyl, C ₁ -C ₁₀ alkyl and C ₂ on a -CH ₂ - C ₁₀ alkenyl group - COO- or -OCO- on, or, C ₁ ~ C ₁₀ alkyl and C ₂ ~ C ₁₀ alkenyl group - may be -O -, -, - CO Two or more but mutually discontinuous -CH ₂ - may be substituted by -O-, -CO-, -COO- or -OCO-. The C ₁ -C ₁₀ alkyl group and the H ₂ -C ₁₀ alkenyl group H may be substituted by F; Z ₁ ~Z ₂ are each independently selected from a single bond, -CH ₂ -CH ₂ -, -CH=CH-, - The H on COO-, -OCO-, -CF ₂ O- or -OCF ₂ -, -CH ₂ -CH ₂ - and -CH=CH- may be substituted by F.

For example, the compound represented by the formula (I) may have the following structure:

Further, the compound represented by the formula (II) may include the following structures: Wherein L ₈ ~ L ₁₄ may be H, F, CH ₃ ; R _{2 is} selected from the group consisting of H, C ₁ -C ₁₅ alkyl and C ₂ -C ₁₅ alkenyl, C ₁ -C ₁₅ alkyl and C a -CH ₂ - group on the ₂ ~ C ₁₅ alkenyl group may be substituted by -O-, -CO-, -COO- or -OCO-, or a C ₁ -C ₁₅ alkyl group and a C ₂ -C ₁₅ alkenyl group. Two or more but mutually discontinuous -CH ₂ - may be substituted by -O-, -CO-, -COO- or -OCO-. The C ₁ -C ₁₅ alkyl group and the H on the C ₂ -C ₁₅ alkenyl group may be substituted by F or CH ₃ . X ₁ is F, Cl, CF ₃ or OCF ₃ .

For example, the compound represented by the formula (II) may have the following structure:

Further, the compound represented by the formula (III) may include the following structures: R ₃ and R ₄ are each independently selected from the group consisting of F, C ₁ -C ₁₅ alkyl and C ₂ -C ₁₅ alkenyl, wherein C ₁ -C ₁₅ alkyl and one on C ₂ -C ₁₅ alkenyl -CH ₂ - may be -O -, - CO -, - COO- or -OCO-, or two or more of the C ₁ ~ C ₁₅ alkyl and C ₂ ~ C ₁₅ alkenyl group and mutually discontinuous - CH ₂ - may be substituted by -O-, -CO-, -COO- or -OCO-. C ₁ -C ₁₅ alkyl and H ₂ -C ₁₅ alkenyl H may be substituted by F or CH ₃ ; A ₉ ~A ₁₂ are each independently selected from 1,4-phenylene, 1,4-cyclohexyl a group consisting of 2,5-extended tetrahydropyranyl and indole-2,5-diyl, and any H in the group may be substituted by F; Z ₄ to Z ₅ are each independently selected from a single bond, -CH ₂ -CH ₂ -, -CH=CH-, -C≡C-, -COO-, -OCO- or -CO-, and at least one of Z ₄ -Z _{5 is} -C≡C-, -CH ₂ H on -CH ₂ - and -CH=CH- may be substituted by F; f and g are each independently an integer of 0 to 2 and are not 0 at the same time.

For example, the compound represented by the formula (III) may have the following structure:

In other embodiments, the liquid crystal medium may further comprise a third component, wherein the third component is a compound represented by formula (IV).

R ₅ and R ₆ are each independently selected from the group consisting of C ₁ -C ₁₅ alkyl and C ₂ -C ₁₅ alkenyl. A ₁₃ and A ₁₄ are each independently selected from the group consisting of 1,4-phenylene, 1,4-cyclohexylene, and 2,5-tetrahydropyranyl. In this embodiment, the content of the first component is 5 wt% to 50 wt%, the content of the second component is 10 wt% to 25 wt%, and the content of the third component is 25 wt%, based on the total weight of the liquid crystal medium. 85wt%. In a preferred embodiment, the content of the first component is 15% by weight to 40% by weight, the content of the second component is 10% by weight to 20% by weight, and the content of the third component is, for example, 40% by weight to 75% by weight. When the liquid crystal medium has the third component, the liquid crystal medium can be further made to have an appropriate viscosity to increase the ease of handling when the liquid crystal medium is used in the manufacturing process.

[experiment]

The production flow of the liquid crystal medium of the present invention will be described in detail below.

[Synthesis Example 1] The preparation method of the compound 3 RIUQU-O2F (formula (I)) is as follows.

Step 1 (Synthesis of Compound A1)

11.2 g of diisopropylamine and 150 ml of anhydrous tetrahydrofuran were added to a 500 ml three-necked flask. The temperature of nitrogen is lowered to -5 ° C, and then 46 ml of n-butyl lithium is added dropwise. Alkane solution (2.4 mol/L), control temperature below 0 °C. After the completion of the dropwise addition, the temperature was continuously controlled at 0 ° C and stirred for 1 hour; then, the temperature was further lowered to -78 ° C, and a mixture of 14.3 g of ethyl valerate and 10 ml of anhydrous tetrahydrofuran was added dropwise. After the completion of the dropwise addition, the mixture was stirred at -78 ° C for 30 minutes; then, a mixture of 25 g of 4-Bromobenzyl bromide and 100 ml of tetrahydrofuran was added dropwise, and after the dropwise addition was completed, the temperature was stirred at -78 ° C. 1 hour; remove the cryogenic equipment, after the temperature of the reaction is raised to room temperature, stir for another 12 hours; after treatment, a pale yellow oil is obtained, and the oil is dissolved in 100 ml of ethanol, and added to 100 ml of 10%. The aqueous sodium hydroxide solution was heated to reflux for 3 hours, and then cooled to room temperature to give a pale yellow solid, which was recrystallized from petroleum ether to give 18 g of white solid, yield 67%.

Step 2 (Synthesis of Compound A2)

Add 18 g of compound A1 and 50 ml of sulfinium chloride to a 250 ml three-necked flask. After heating to reflux for 3 hours, distill off excess sulphur sulphide chloride. Then, add 120 ml of dichloromethane to dissolve and lower the temperature under nitrogen. To 0 ° C, a total of 10 g of anhydrous aluminum trichloride was added in portions, followed by reflux for 5 hours; after treatment, 14 g of a yellow solid was obtained, the yield was 83%, purity (measured by gas chromatograph GC) 99%.

Step 3 (Synthesis of Compound A3)

14 g of compound A2, 23 ml of triethyldecane and 40 ml of trifluoroacetic acid were added to a 250 ml three-necked flask, and the mixture was stirred at room temperature for 12 hours. Then, the reaction liquid was poured into an aqueous solution of sodium carbonate, and the pH was adjusted to 7-8 to obtain a yellow oil. The residue was evaporated to give a colorless transparent liquid 12 g, yield 91%, purity (by gas chromatography GC) Measure) 97%.

Step 4 (Synthesis of Compound A4)

12 g of compound A3, 7.9 g of 3,5-difluorophenylboronic acid, 21.3 g of sodium carbonate, 100 ml of water, 100 ml of ethanol, 200 ml of toluene and 0.5 g of Pd(PPh ₃ ) _{4 were} added to a 1000 ml three-necked flask. Heat under reflux for 6 hours under nitrogen. Treated as a pale yellow oil, recrystallized from ethanol to give a white solid 10.2 g, yield 75%, purity (measured by gas chromatograph GC) 99%.

Step 5 (Synthesis of Compound A5)

18 g of compound A4 and 200 ml of anhydrous tetrahydrofuran were added to a 500 ml three-necked flask, and the temperature was lowered to -100 ° C under nitrogen, and 28 ml of a n-hexane solution of n-BuLi (2.4 mol/L) was added dropwise. After the completion of the dropwise addition, the temperature was stirred at -100 ° C for 1 hour, and 28 g of difluorodibromomethane was added dropwise. After the completion of the dropwise addition, the mixture was stirred at a temperature of -100 ° C for 1 hour, and returned to room temperature for hydrolysis; after treatment, 23.8 g was obtained. Yellow solid-liquid mixture; yield 90%.

Step 6 (Synthesis of Compound A6)

In a 500 ml three-necked flask, 29 g of compound A5, 300 ml of DMF, 9.9 g of 1-trifluoroethoxy 2,6-difluorophenol, 6.6 g of anhydrous potassium carbonate, 0.7 g of potassium iodide were added, and the mixture was stirred at 90 ° C for 0.5 hour in a water bath. After cooling, pour into water and obtain 11 g of white solid after treatment. Purity (measured by gas chromatograph GC) 99.7%, the yield is 50%.

Step 7 (Synthetic Compound 3 RIUQU-O2F)

Add 1.2g of diisopropylamine and 20ml of anhydrous tetrahydrofuran to a 50ml three-necked flask, cool down to -5 °C with nitrogen, add 4.6 ml of n-hexane solution of n-butyllithium (2.4 mol / L), and control the temperature. After 0 ° C, after the completion of the dropwise addition, stirring was continued for 1 hour; in another 250 ml three-necked flask, 5.5 g of compound A6 and 80 ml of anhydrous tetrahydrofuran were added, and the temperature was lowered to -65 ° C under nitrogen, and the prepared LDA was added dropwise. , stirring for 0.5 h, treatment, ethanol recrystallized white solid 3.0 g, purity (measured by gas chromatography GC) 99.5%, melting point 38 ° C.

[Synthesis Example 2] The preparation method of the compound 3 RIGUQUF (formula (II)) is as follows:

Step 1 (Synthesis of Compound 1d)

229 g of 4-bromophenylpropionic acid and 357 g of aluminum chloride were placed in a 2 L three-necked flask and heated to reflux for 3 hours. Then, the excess aluminum chloride was removed and 1.2 L of dichloromethane was added. Next, the temperature was lowered to 5 ° C, and 3200 g of AlCl was added. Then, the mixture was refluxed for 5 hours, and the reaction liquid was poured into a mixture of hydrochloric acid and ice to carry out hydrolysis, extraction, and separation with a silicone gel. Thereafter, the solvent was removed to give 168.8 g of a pale yellow solid (yield: 80%, purity (measured by gas chromatograph) was greater than 97%).

Step 2 (Synthesis of Compound 2d)

168.8 g of 1 d, 650 ml of ethanol was added to a 1 L three-necked flask. Then, the temperature was controlled below 10 ° C, and 45 g of NaBH 4 was added in portions. Next, the temperature was raised to room temperature and stirring was continued for 3 hours. After completion of the reaction, the ethanol was removed, and 450 ml of a 10% aqueous hydrochloric acid solution was added thereto for hydrolysis, extraction with dichloromethane, washing with water, drying, and removal of solvent to give 170 g of pale yellow solid (yield for 100%, purity (measured by gas chromatography) greater than 97%).

Step 3 (Synthesis of Compound 3d)

170 g of 2d, 1.2 L of benzene, and 8 g of p-toluenesulfonic acid were placed in a 2 L three-necked flask and refluxed for 3 hours. After the reaction was completed, it was washed with water until neutral, and benzene was removed. Next, it was filtered with 750 ml of petroleum ether and silicone. Thereafter, petroleum ether was removed to give 148 g of a pale yellow oil (yield 95%, purity (measured by gas chromatograph) greater than 95%).

Step 4 (Synthesis of Compound 4d)

1.5 L of formic acid, 300 ml of 30% H 2 O 2 was added to a 2 L three-necked flask, and the temperature was controlled between 35 ° C and 40 ° C in a water bath. Then, add 148 g of 3d. Then, it was stirred at room temperature for 12 hours. Then, the reaction liquid was poured into a large amount of water to precipitate a white solid, which was filtered. Following this, 3 L of a 7% aqueous solution of sulfuric acid was added to a 5 L three-necked flask and heated to boiling. Then, the above white solid was added to the reaction flask. Thereafter, it was steam distilled to obtain 64 g of a white solid (yield 40%, purity (measured by gas chromatograph) was more than 95%).

Step 5 (Synthesis of Compound 5d)

64 g of 4d, 90 ml of ethylene glycol, 600 ml of toluene and 3 g of p-toluenesulfonic acid were placed in a 1 L three-necked flask and heated to reflux for 3.5 hours. Then, the heating was stopped and washed with water until neutral. Next, toluene was removed and separated with 500 ml of petroleum ether and silicone. Thereafter, petroleum ether was removed and recrystallized from 150 ml of isopropyl alcohol to give 61 g of a pale yellow solid (yield: 80%, purity (measured by gas chromatograph) of greater than 99%).

Step 6 (Synthesis of Compound 6d)

Add 42 g of 5d, 23.1 g of m-fluorophenylboronic acid, 70 g of sodium carbonate, 300 ml of water, 300 ml of ethanol, 600 ml of toluene and 2 g of Pd(PPh3)4 to a 2 L three-necked flask in. Then, heating under reflux for 6 hours under nitrogen atmosphere. Next, the obtained gray-black solid was subjected to petroleum ether column chromatography. Thereafter, recrystallization was carried out to obtain 38 g of a pale yellow solid (yield: 85%, purity (measured by gas chromatograph) was more than 99%).

Step 7 (Synthesis of Compound 7d)

38 g of 6d, 200 ml of 84% aqueous formic acid and 150 ml of toluene were added to a 500 ml three-necked flask. Then, the temperature was controlled at 20 ° C and stirred for 20 hours. After completion of the reaction, it was separated by water extraction and then crystallized from isopropyl alcohol to give 28 g of pale yellow solid (yield: 88%, purity (measured by gas chromatograph) of more than 99%).

Step 8 (Synthesis of Compound 8d)

3.3 g of magnesium turnings, 50 ml of anhydrous tetrahydrofuran, one iodine and a few drops of bromopropane were added to a 500 ml three-necked flask. Then, it was heated slightly under the protection of nitrogen. After the reaction was initiated, a mixture of 18 g of bromopropane and 150 ml of anhydrous tetrahydrofuran was added dropwise (dropping acceleration so as not to cause the temperature to rise extremely sharply and to maintain a slow reflux). After the completion of the dropwise addition, refluxing was carried out for 1 hour. Then, the reaction temperature was lowered to -10 ° C, and a mixture of 28 g of 7d and 150 ml of anhydrous tetrahydrofuran was further added dropwise. After the dropwise addition was completed, the temperature was controlled at -10 ° C and stirred for 12 hours. Next, the reaction liquid was poured into a mixture of hydrochloric acid and ice to be hydrolyzed, and extracted twice with toluene. Then, the extract was distilled to about 250 ml, and 1 g of p-toluenesulfonic acid was further added thereto. Subsequently, the mixture was dehydrated under reflux for 2 hours to give a brownish red oil. Thereafter, column chromatography was carried out, and recrystallization purification was carried out to obtain 10 g of a pale yellow solid (yield: 32%, purity (measured by gas chromatograph) was more than 99%).

Step 9 (Synthesis of Compound 9d)

10 g of 8d, 1g of 5% Pd/C, 100 ml of ethanol and 100 ml of toluene were added to a 1 L hydrogen kettle, the hydrogen pressure was adjusted to 1 MP, and hydrogen was added at 25 ° C for 6 hours to obtain 9.5. A white solid of g (yield 94%, purity (measured by gas chromatograph) greater than 99%).

Step 10 (Synthesis of Compound 10d)

9.5 g of 9d, 4.2 g of t-BuOK and 100 ml of anhydrous tetrahydrofuran were added to a 250 ml three-necked flask. Then, under a nitrogen atmosphere, the temperature was lowered to -100 ° C, and 17 ml of a n-BuLi n-hexane solution (2.4 mol/L) was added dropwise. After the dropwise addition was completed, the temperature was controlled at -100 ° C and stirred for 1 hour. Next, a mixture of 9.5 g of triisobutyl borate and 50 ml of anhydrous tetrahydrofuran was added. After the dropwise addition was completed, the temperature was controlled at -100 ° C and stirred for 1 hour. Thereafter, the temperature was raised to room temperature to carry out hydrolysis to obtain 7.2 g of a yellow solid (yield: 65%).

Step 11 (Synthetic Compound 3RIGUQUF)

Add 7.2 g of 10 d, 9.4 g of diphenylfluorocyclobromo compound, 10.2 g of sodium carbonate, 50 ml of water, 50 ml of ethanol, 100 ml of toluene and 0.25 g of Pd(PPh ₃ ) ₄ to 500 ml In the three-necked bottle. Then, heating under reflux for 6 hours under nitrogen atmosphere. After the usual workup, a pale yellow oil was obtained. Next, petroleum ether column chromatography was carried out and recrystallized several times under ethanol. Thereafter, purification was carried out to obtain 5 g of a white solid (yield 45%, purity (measured by gas chromatograph) was more than 99.9%).

[Synthesis Example 3] The preparation method of the compound 3CPTP4 (formula (III)) is as follows:

0.180 mol of anhydrous aluminum chloride was added to 200 ml of carbon disulfide, and 0.150 mol (trans-4-propyl-1-phenylcyclohexane) was added dropwise while heating the solution under reflux. 0.150 mole (4-n-butylphenylacetyl chloride) and 50 ml of carbon disulfide were added, and the reaction mixture was refluxed for 1 hour. Next, the reaction mixture was cooled to 60 ° C and stirred for 1 hour. After the carbon disulfide is concentrated and volatilized, it is toluene (toluene) extraction, washing with water, and drying with anhydrous sodium sulfate (anhydrous sodium sulfate). After the toluene was concentrated and volatilized, it was recrystallized from ethanol-toluene (2:1) to give the following compound b1.

After dissolving the compound b1 in tetrahydrofuran (THF), it was added dropwise to a mixed solution containing 0.131 moles of aluminum lithium hydride and 150 ml of THF, and refluxed for 2 hours. Next, 250 ml of HCl (hydrochloric acid) and 250 ml of water were added dropwise. The mixture was extracted with toluene, washed with water, and dried over anhydrous sodium sulfate (Nahydrous sodium sulfate), and the solvent was concentrated and evaporated to give a crude product of the compound b2 below.

The crude product of compound b2 was dissolved in 300 ml of toluene and 0.0262 moles of hydrogen hydrogen sulfate was added to carry out a dehydration reaction, and water was removed as a decanter. After the reaction was completed, the reaction was washed with water and dried. After the toluene concentration was volatilized, it was recrystallized from ethanol-toluene (2:1) to give the following compound b3.

Compound b3 was dissolved in 200 ml of 1,1,2-trichloroethane, stirred at 10 ° C, and added dropwise to 9,913 mol. Bromine and react for 2 hours. After the reaction mixture was cooled, the solid was filtered, washed with methanol and dried. Next, the solid was dissolved in 250 ml of N,N-dimethylformamide (DMF) and 0.0908 mol of 1,5-diazabicyclo[5.4.0] eleven was added. Ethene-5 (1,5-diazabicyclo [5.4.0] undecene-5), refluxed for 5 hours. After the reaction was completed, water was added after the reaction mixture was cooled. After the reaction mixture was cooled, the solid was filtered, washed with methanol and dried. Recrystallization was then carried out with ethanol-toluene (1:2) to give the compound 3CPTP4.

Hereinafter, a liquid crystal display device of a plurality of examples and comparative examples will be described, and the composition of the liquid crystal medium used in each liquid crystal display device and various characteristics of the liquid crystal display device will be described.

First, the codes of the liquid crystal compounds used in the examples and comparative examples and their corresponding structural formulae are summarized in Table 1.

The composition ratios and characteristics of the liquid crystal medium of Comparative Example 1 and Example 1 are shown in Table 2.

As is clear from Table 2, Example 1 including the second component (i.e., the compound represented by the formula (III)) has a high phase transition temperature and thus has better heat stability as compared with the liquid crystal medium of Comparative Example 1. Moreover, the liquid crystal medium of Example 1 has good dielectric properties and high birefringence.

The composition ratios and characteristics of the liquid crystal media of Comparative Example 2 and Example 2 are detailed in Table 3.

As can be seen from Table 3, the liquid crystal medium of Comparative Example 2 includes both the first component (the compound represented by the formula (I) and the formula (II)) and the second component (the compound represented by the formula (III). Example 2 of the composition) has good dielectric properties and high birefringence.

The composition ratios and characteristics of the liquid crystal media of Comparative Example 3, Comparative Example 4, Comparative Example 5, and Example 3 are detailed in Table 4.

As is clear from Table 4, Example 3 including the compound represented by the formula (I), the formula (II) and the formula (III) was excellent in comparison with the liquid crystal medium of Comparative Example 3, Comparative Example 4 and Comparative Example 5. Dielectric properties and high birefringence.

The composition ratios and characteristics of the liquid crystal media of Examples 4 to 11 are detailed in Table 5.

Table 5

In summary, the liquid crystal medium of the present invention includes the first component and the second component, and thus has high thermal stability, good dielectric properties, and high birefringence. In addition, The liquid crystal display device of the present invention includes the above liquid crystal medium, and thus has good display quality and a low driving voltage.

Claims (13)

A liquid crystal medium comprising: a first component selected from at least one compound of the group consisting of compounds represented by formula (I) to formula (II), wherein, based on the total weight of the liquid crystal medium, The first component is contained in an amount of 15% by weight to 40% by weight; and the second component is a compound represented by the formula (III), R _{1 is} selected from the group consisting of H, C ₁ -C ₁₀ alkyl and C ₂ -C ₁₀ alkenyl, one or more of C ₁ -C ₁₀ alkyl and C ₂ -C ₁₀ alkenyl but mutual discontinuous -CH ₂ - may be -O - or -OCO- COO-, H on C ₁ ~ C ₁₀ alkyl and C ₂ ~ C ₁₀ alkenyl group may be substituted with F, - CO - -,; a ₁ to A ₄ are each independently selected from the group consisting of 1,4-phenylene, 1,4-cyclohexylene, 2,5-tetrahydropyranyl and indane-2,5-diyl, A At least one of ₁ to A _{4 is} an indane-2,5-diyl group, a 1,4-phenylene group, and an indane-2,5-diyl group may be substituted by F or CH ₃ ; Z ₁ to Z ₃ Each is independently selected from the group consisting of a single bond, -CH ₂ -CH ₂ -, -CH=CH-, -COO-, -OCO-, -CF ₂ O- or -OCF ₂ -, -CH ₂ -CH ₂ - and -CH H on =CH- may be substituted by F; m, n, o, and p are each independently an integer of 0-2 and not 0 at the same time; R _{2 is} selected from the group consisting of H, C ₁ -C ₁₅ alkyl and C ₂ -C ₁₅ alkenyl, wherein one or more of C ₁ -C ₁₅ alkyl and C ₂ -C ₁₅ alkenyl but The mutually discontinuous -CH ₂ - may be substituted by -O-, -CO-, -COO- or -OCO-, the C ₁ -C ₁₅ alkyl group and the H on the C ₂ -C ₁₅ alkenyl group may be F or CH ₃ substituted; X ₁ is F, Cl, CF ₃ or OCF ₃ ; A ₅ ~ A ₇ are each independently selected from 1,4-phenylene, 1,4-cyclohexylene, 2,5-extended tetrahydropyran a group consisting of a base and a full-2,5-diyl group, at least one of A ₅ ~A ₇ is indole-2,5-diyl, A ₈ is 1,4-phenylene, 1,4-extension H on phenyl and indan-2,5-diyl may be substituted by F; L is -CF ₂ O-; t is 1, q, r and s are each independently an integer from 0 to 3 and q+r+ S≧3; R ₃ and R ₄ are each independently selected from the group consisting of F, C ₁ -C ₁₅ alkyl and C ₂ -C ₁₅ alkenyl, wherein C ₁ -C ₁₅ alkyl and one on C ₂ -C ₁₅ alkenyl two or more but not mutually contiguous -CH ₂ - may be -O - or -OCO- COO-, H on C ₁ ~ C ₁₅ alkyl and C ₂ ~ C ₁₅ alkenyl -, - CO -, It may be substituted by F or CH ₃ ; A ₉ ~ A ₁₂ are each independently selected from 1,4-phenylene, 1,4-cyclohexylene, 2,5-tetrahydropyranyl and indole-2,5 a group consisting of a dibasic group, and any H in the group may be substituted by F; Z ₄ to Z ₅ are each independently selected from a single bond, -CH ₂ -CH ₂ -, -CH=CH-, -C≡C -, -COO-, -OCO- or -CO-, and at least one of Z ₄ -Z _{5 is} -C≡C-, -CH ₂ -CH ₂ - and H on -CH=CH- may be substituted by F; f and g are each independently an integer of 0 to 2 and are not 0 at the same time. The liquid crystal medium according to claim 1, wherein the first component comprises a compound represented by the formula (I) and a compound represented by the formula (II). The liquid crystal medium according to claim 1, wherein the liquid crystal medium is The content of the second component is from 10% by weight to 25% by weight based on the total weight of the mass. The liquid crystal medium according to claim 1, further comprising a third component which is a compound represented by the formula (IV), R ₅ and R ₆ are each independently selected from the group consisting of C ₁ -C ₁₅ alkyl and C ₂ -C ₁₅ alkenyl; A ₁₃ and A ₁₄ are each independently selected from 1,4-phenylene, 1,4- A group consisting of a cyclohexyl group and a 2,5-extended tetrahydropyranyl group. The liquid crystal medium according to claim 4, wherein the content of the third component is from 25 wt% to 85 wt% based on the total weight of the liquid crystal medium. The liquid crystal medium according to claim 5, wherein the third component is contained in an amount of 40% by weight to 75% by weight based on the total weight of the liquid crystal medium. The liquid crystal medium according to claim 1, wherein the formula (I) comprises the following structure: Wherein L ₁ ~ L ₆ may be H, F, CH ₃ ; R _{1 is} selected from the group consisting of H, C ₁ -C ₁₀ alkyl and C ₂ -C ₁₀ alkenyl, C ₁ -C ₁₀ alkyl and C One or more but not mutually discontinuous -CH ₂ - groups on the ₂ ~ C ₁₀ alkenyl group may be substituted by -O-, -CO-, -COO- or -OCO-, C ₁ -C ₁₀ alkyl and C on ₂ H ~ C ₁₀ alkenyl group may be substituted with F; Z ₁ ~ Z ₂ are each independently selected from a single _{bond, -CH 2 -CH 2 -, -} CH = CH -, - COO -, - OCO -, - CF ₂ O- or -OCF ₂ -, -CH ₂ -CH ₂ - and -CH=CH-H may be substituted by F. The liquid crystal medium according to claim 1, wherein the formula (II) comprises the following structure: Wherein L ₈ ~ L ₁₄ may be H, F, CH ₃ ; R _{2 is} selected from the group consisting of H, C ₁ -C ₁₅ alkyl and C ₂ -C ₁₅ alkenyl, C ₁ -C ₁₅ alkyl and C One or more but non-contiguous -CH ₂ - groups on the ₂ ~ C ₁₅ alkenyl group may be substituted by -O-, -CO-, -COO- or -OCO-, C ₁ -C ₁₅ alkyl and C H on the ₂ to C ₁₅ alkenyl group may be substituted by F or CH ₃ ; X ₁ is F, Cl, CF ₃ or OCF ₃ . The liquid crystal medium according to claim 1, wherein the formula (III) comprises the following structure: R ₃ and R ₄ are each independently selected from the group consisting of F, C ₁ -C ₁₅ alkyl and C ₂ -C ₁₅ alkenyl, wherein C ₁ -C ₁₅ alkyl and one on C ₂ -C ₁₅ alkenyl Or two or more but mutually discontinuous -CH ₂ - may be substituted by -O-, -CO-, -COO- or -OCO-, C ₁ -C ₁₅ alkyl group and H on C ₂ -C ₁₅ alkenyl group ₃ may be substituted with F or CH; A ₉ ~ A ₁₂ are each independently selected from the group consisting of 1,4-phenylene, 1,4-cyclohexylene, 2,5-tetrahydropyranyl, and extending indan-2,5 a group consisting of a dibasic group, and any H in the group may be substituted by F; Z ₄ to Z ₅ are each independently selected from a single bond, -CH ₂ -CH ₂ -, -CH=CH-, -C≡C -, -COO-, -OCO- or -CO-, and at least one of Z ₄ -Z _{5 is} -C≡C-, -CH ₂ -CH ₂ - and H on -CH=CH- may be substituted by F; f and g are each independently an integer of 0 to 2 and are not 0 at the same time. The liquid crystal medium according to claim 1, wherein the formula (I) comprises the following structure: The liquid crystal medium according to claim 1, wherein the formula (II) comprises the following structure: The liquid crystal medium according to claim 1, wherein the formula (III) comprises the following structure: A liquid crystal display device comprising the liquid crystal medium according to any one of claims 1 to 12.