阅读说明：本技术 光稳定剂化合物及包含其的液晶组合物 (Light stabilizer compound and liquid crystal composition containing same ) 是由 金成珉 赵泰杓 安贤九 金奉熙 尹志昊 于 2019-08-16 设计创作，主要内容包括：本发明涉及光稳定剂化合物及包含其的液晶组合物,本发明可提供如下液晶组合物,本发明的光稳定剂化合物可有效改善液晶显示装置的残像,且溶解性好,可确保液晶组合物的低温稳定性,并可显著减少光稳定剂凝聚引起的漏光现象。上述光稳定剂化合物由以下化学式1表示,在所述化学式1中,R<Sub>1</Sub>及R<Sub>2</Sub>各自独立地为氢H、OH、O·、碳C原子数为1～10个的烷基或碳C原子数为1～10个的烷氧基,R<Sub>3</Sub>至R<Sub>5</Sub>各自独立地为氢H、碳C原子数为1～10个的直链形、支链形或环形烷基或碳C原子数为1～10个的烷氧基,此时,亚甲基CH<Sub>2</Sub>能够由氧O或乙烯基CH＝CH取代,n为0或1的整数,当n为0时,虚线能够形成实线。化学式1<Image he="279" wi="700" file="DDA0002169764370000011.GIF" imgContent="drawing" imgFormat="GIF" orientation="portrait" inline="no"></Image>(The present invention relates to a light stabilizer compound and a liquid crystal composition comprising the same, and the present invention can provide a liquid crystal composition which can effectively improve the afterimage of a liquid crystal display device, has good solubility, can ensure the low-temperature stability of the liquid crystal composition, and can significantly reduce the light leakage phenomenon caused by the aggregation of the light stabilizer. The above light stabilizer compound is represented by the following chemical formula 1, in the chemical formula 1, R 1 And R 2 Each independently hydrogen H, OH, O, C1-10 alkyl or C1-10Alkoxy radical, R 3 To R 5 Independently of each other, hydrogen H, a linear, branched or cyclic alkyl group having 1 to 10 carbon atoms or an alkoxy group having 1 to 10 carbon atoms, in which case the methylene group CH 2 Can be substituted with O or CH, n is an integer of 0 or 1, and when n is 0, the dotted line can form a solid line. Chemical formula 1)

1. A light stabilizer compound characterized in that,

represented by the following chemical formula 1,

chemical formula 1

In the chemical formula 1, the first and second organic solvents,

R₁and R₂Each independently hydrogen H, OH, O, C1-10 alkyl or C1-10 alkoxy,

R₃to R₅Each independently hydrogen H, C1-10 linear, branched or cyclic alkyl or C1-10 alkoxy,

at this time, methylene CH₂Can be substituted by oxygen O or vinyl CH ═ CH,

n is an integer of 0 or 1, and when n is 0, the dotted line can form a solid line.

2. Light stabilizer compound according to claim 1, characterized in that,

the compound is represented by the following chemical formula 2,

chemical formula 2

In the chemical formula 2,

R₁to R₄As defined in said chemical formula 1.

3. Light stabilizer compound according to claim 1, characterized in that,

the compound is represented by the following chemical formula 2-1,

chemical formula 2-1

In the chemical formula 2-1,

R₁and R₂As defined in said chemical formula 1.

4. Light stabilizer compound according to claim 1, characterized in that,

the compound is represented by the following chemical formula 3,

chemical formula 3

In the chemical formula 3, the first and second organic solvents,

R₁to R₅As defined in said chemical formula 1.

5. Light stabilizer compound according to claim 1, characterized in that,

the compound is represented by one of the compounds represented by the following chemical formulas 3-1 to 3-4,

chemical formula 3-1

Chemical formula 3-2

Chemical formula 3-3

Chemical formula 3-4

In the chemical formulas 3-1 to 3-4,

R₁to R₅As defined in said chemical formula 1.

6. A liquid crystal composition characterized in that,

comprising a light stabilizer compound represented by the following chemical formula 1,

chemical formula 1

In the chemical formula 1, the first and second organic solvents,

R₁and R₂Each independently hydrogen H, OH, O, C1-10 alkyl or C1-10 alkoxy,

R₃to R₅Each independently hydrogen H, C1-10 linear, branched or cyclic alkyl or C1-10 alkoxy,

at this time, methylene CH₂Can be substituted by oxygen O or vinyl CH ═ CH,

n is an integer of 0 or 1, and when n is 0, the dotted line can form a solid line.

7. The liquid crystal composition according to claim 6,

the light stabilizer compound is represented by the following chemical formula 2 or chemical formula 3,

chemical formula 2

Chemical formula 3

In the chemical formulas 2 and 3,

R₁to R₅As defined in said chemical formula 1.

8. The liquid crystal composition of claim 6, wherein the light stabilizer compound is contained in an amount of 0.001 to 1 part by weight based on 100 parts by weight of the liquid crystal composition.

9. The liquid crystal composition according to claim 6,

comprising 1 or 2 or more compounds represented by the following chemical formula 4,

chemical formula 4

In the chemical formula 4, the first and second organic solvents,

R₇an alkyl group having 1 to 8 carbon atoms, an alkenyl group having 2 to 8 carbon atoms or an alkoxy group having 1 to 8 carbon atoms, in which case the hydrogen H atom can be replaced by a halogen,

R₈is alkyl with 1 to 8 carbon atoms, alkenyl with 2 to 8 carbon atoms or alkoxy with 1 to 8 carbon atoms, in this case, more than one methylene CH₂Can be independently of each other bound by-C.ident.C-, -CF in such a way that oxygen O atoms are not directly bound to each other₂O-、-OCF₂-, -CH-, -O-, -CO-O-, -O-CO-or-O-CO-O-, the hydrogen H atom being able to be replaced by halogen,

ring A, B and C are each independently trans-1,4-cyclohexyl whose endocarbon C in the ring can be substituted by 1 or 2 oxo-O, trans-1,4-cyclohexyl whose hydrogen H can be substituted by 1 fluoro-F, or 1,4-phenylene whose hydrogen H can be substituted by 1 fluoro-F,

i and j are each independently an integer of 0, 1 or 2, and when i or j is 2, the phenylene groups or the rings C can each be the same or different.

10. The liquid crystal composition according to claim 9,

the compound represented by the chemical formula 4 includes compounds represented by the following chemical formulas 4-1 to 4-7,

chemical formula 4-1

Chemical formula 4-2

Chemical formula 4-3

Chemical formula 4-4

Chemical formula 4-5

Chemical formula 4-6

Chemical formula 4-7

In the chemical formulas 4-1 to 4-7,

R₇and R₈As defined in said chemical formula 4.

11. The liquid crystal composition of claim 8, wherein the compound represented by the chemical formula 4 is contained in an amount of 10 to 75 parts by weight in 100 parts by weight of the liquid crystal composition.

12. The liquid crystal composition according to claim 6 or 9,

the liquid crystal composition includes 1 or 2 or more compounds represented by the following chemical formula 5,

chemical formula 5

In the chemical formula 5, the first and second organic solvents,

R₉is hydrogen H, linear, branched or cyclic alkyl with 1 to 8 carbon atoms, alkoxy with 1 to 8 carbon atoms or alkenyl with 2 to 8 carbon atoms, in which case more than one methylene CH₂Can be independently of each other bound by-C.ident.C-, -CF in such a way that oxygen O atoms are not directly bound to each other₂O-、-OCF₂-, -CH-, -O-, -CO-O-, -O-CO-or-O-CO-O-, the hydrogen H atom being able to be replaced by halogen,

X₁to X₃Each independently hydrogen H, fluorine F or trifluoromethoxy OCF₃，

Y₁Is hydrogen H or methyl CH₃，

Rings D to F are each independently trans-1,4-cyclohexyl whose endocarbon C in the ring can be substituted by 1 or 2 oxo or 1,4-phenylene whose hydrogen H can be substituted by 1 or 2 fluoro F,

k. l and m are each independently an integer of 0 or 1.

13. The liquid crystal composition according to claim 12,

the compound represented by the chemical formula 5 includes compounds represented by the following chemical formulas 5-1 to 5-18,

chemical formula 5-1

Chemical formula 5-2

Chemical formula 5-3

Chemical formula 5-4

Chemical formula 5-5

Chemical formula 5-6

Chemical formula 5-7

Chemical formula 5-8

Chemical formula 5-9

Chemical formula 5-10

Chemical formula 5-11

Chemical formulas 5 to 12

Chemical formula 5-13

Chemical formulas 5 to 14

Chemical formula 5-15

Chemical formula 5-16

Chemical formula 5-17

Chemical formulas 5 to 18

In the chemical formulas 5-1 to 5-18,

R₉as defined in the chemical formula 5,

f is hydrogen H or fluorine F.

14. The liquid crystal composition of claim 12, wherein the compound represented by the chemical formula 5 is contained in an amount of 5 to 60 parts by weight in 100 parts by weight of the liquid crystal composition.

15. The liquid crystal composition according to claim 6 or 9,

the liquid crystal composition includes 1 or 2 or more compounds represented by the following chemical formula 6,

chemical formula 6

In the chemical formula 6, the first and second organic solvents,

R₁₀and R₁₁Each independently is an alkyl group having 1 to 8 carbon atoms, an alkenyl group having 2 to 8 carbon atoms or an alkoxy group having 1 to 8 carbon atoms, in which case, one or more methylene groups CH₂Can be independently of each other bound by-C.ident.C-, -CF in such a way that oxygen O atoms are not directly bound to each other₂O-、-OCF₂-, -CH-, -O-, -CO-O-, -O-CO-or-O-CO-O-, the hydrogen (H) atom can be replaced by halogen,

ring G, H and I are each independently trans-1,4-cyclohexyl whose endocarbon C in the ring can be substituted by 1 or 2O-oxo or 1,4-phenylene whose hydrogen H can be substituted by 1 or 2F-fluoro,

Z₁is a single bond, -CH₂O-、-OCH₂-、-CH₂CH₂-、-CF₂O-or-OCF₂-，

n, o and p are each independently an integer of 0 or 1.

16. The liquid crystal composition according to claim 15,

the compound represented by the chemical formula 6 includes compounds represented by the following chemical formulas 6-1 to 6-11,

chemical formula 6-1

Chemical formula 6-2

Chemical formula 6-3

Chemical formula 6-4

Chemical formula 6-5

Chemical formula 6-6

Chemical formula 6-7

Chemical formula 6-8

Chemical formula 6-9

Chemical formula 6-10

Chemical formula 6-11

In the chemical formulas 6-1 to 6-11,

R₁₀and R₁₁As defined in said chemical formula 6.

17. The liquid crystal composition of claim 15, wherein the compound represented by chemical formula 6 is contained in an amount of 5 to 85 parts by weight in 100 parts by weight of the liquid crystal composition.

18. The liquid crystal composition according to claim 6,

the liquid crystal composition includes 1 or 2 or more antioxidants represented by the following chemical formula 7,

chemical formula 7

In the chemical formula 7, the first and second organic solvents,

R₁₂is alkyl with 1 to 12 carbon atoms,

ring J is trans-1,4-cyclohexyl, tetrahydropyran or dioxane,

q is an integer of 0, 1 or 2, and when q is 2, the rings J can be the same or different.

19. The liquid crystal composition of claim 18, wherein the antioxidant represented by the chemical formula 7 is contained in an amount of 0.005 to 0.05 parts by weight in 100 parts by weight of the liquid crystal composition.

20. A liquid crystal display device comprising the liquid crystal composition according to any one of claims 6 to 11, 13, 14, and 16 to 19.

Technical Field

The present invention relates to a light stabilizer compound and a liquid crystal composition comprising the same.

Background

A Liquid Crystal Display (LCD) is one of the most widely used flat panel displays (flat panel displays) at present. The liquid crystal display device generates an electric field in the liquid crystal layer by applying a voltage to the electric field generating electrodes to orient a plurality of liquid crystal molecules of the liquid crystal layer and adjusts light transmittance through the liquid crystal layer, so that a switch (ON/OFF) can be displayed. As modes applicable to this, various liquid crystal display devices have been developed, such as Twisted Nematic (TN), In-Plane Switching (IPS), Fringe Field Switching (FFS), Vertical Alignment (VA), Electrically Controlled Birefringence (ECB), Optically Compensated Bend (OCB), Super Twisted Nematic (STN), Polymer Stabilized Alignment (PSA), and Polymer Stabilized Vertical Alignment (PSVA).

In general, a twisted nematic liquid crystal display (TN LCD) is most widely used in the process unit price and front view angle, and is mainly used for personal applications such as displays and notebook personal computers. In recent smartphones, a fringe field switching (PLS) and an AH-in-plane switching (AH-in-plane switching) having high luminance characteristics are the core technology, and a fringe field switching using a vertical alignment liquid crystal is developed for high luminance.

Further, since the unit cost of the fringe field switching mode (mode) is reduced, the mode is currently used in a display or a notebook computer, and the possibility that all devices (devices) will be switched to in-plane switching, fringe field switching, and vertical alignment is high in the future.

In contrast, in-plane switching, fringe field switching, vertical alignment devices are weaker at the image-stop plane of the liquid crystal display than twisted nematic devices.

The afterimage effect of the liquid crystal display is a phenomenon in which an afterimage is generated because a new picture is overlapped with a previous image due to a slow response speed of liquid crystals constituting the liquid crystal display.

The Residual image is classified into Direct Current (DC) Residual image (image sticking) and Alternating Current (AC) Residual image (image sticking), and the smaller the Residual direct current Voltage (RDC) between the liquid crystal layer and the alignment layer, the smaller the ion adsorption speed in the liquid crystal layer, and the more favorable the direct current Residual image. Also, in the case of an ac afterimage, the matching of the alignment agent and the liquid crystal layer is important.

In order to improve the afterimage, it is considered to minimize the afterimage of the liquid crystal and the alignment agent as the material of the liquid crystal display device when developing a liquid crystal display device panel (LCD panel). In order to minimize the residual image of the liquid crystal, additives such as a polymerizable compound, a polymerization initiator, a polymerization inhibitor, an optically active compound, an antioxidant, an ultraviolet absorber, a light stabilizer, and a heat stabilizer are added as necessary. Among these, the light stabilizer has an effect of preventing the liquid crystalline compound from being decomposed by light from a backlight or the sun. By this effect, a high voltage holding ratio of the device is maintained, and thus the lifetime of the device becomes long.

It is known from many conventional documents that the use of various light stabilizers including Hindered Amine Light Stabilizers (HALS) improves the level of afterimage in a liquid crystal display device, but the effects thereof are still insufficient. In particular, conventional light stabilizers have a disadvantage that they have reactivity with moisture and an alignment film, and when they are aged for a long time, they may cause a light leakage phenomenon due to aggregation of reactants in a display. Therefore, the reduction of afterimages and the low temperature stability caused by the addition of light stabilizers, the minimization of light leakage phenomenon, and the like are still problems to be improved.

Disclosure of Invention

The invention provides a light stabilizer compound and a liquid crystal composition containing the same.

One embodiment of the present invention provides a light stabilizer compound represented by the following chemical formula 1.

Chemical formula 1

In the above-described chemical formula 1,

R₁and R₂Independently represents hydrogen (H), OH, O, an alkyl group having 1 to 10 carbon (C) atoms or an alkoxy group having 1 to 10 carbon (C) atoms,

R₃to R₅Each independently hydrogen (H), a linear, branched or cyclic alkyl group having 1 to 10 carbon (C) atoms or an alkoxy group having 1 to 10 carbon (C) atoms,

at this time, methylene group (CH)₂) May be substituted by oxygen (O) or vinyl (CH ═ CH),

n is an integer of 0 or 1, and when n is 0, the dotted line may form a solid line.

Still another embodiment of the present invention provides a liquid crystal composition comprising a light stabilizer compound according to an embodiment of the present invention.

Another embodiment of the present invention provides a liquid crystal display device including the liquid crystal composition of an example of the present invention.

The light stabilizer compounds of the present invention are suitable for use in liquid crystal compositions having positive or negative dielectric anisotropy.

Further, the light stabilizer compound of the present invention can improve the image sticking level more than the conventional compounds, and can ensure low temperature stability because of its good solubility. Further, the light leakage phenomenon caused by the reaction of moisture, an alignment film and a light stabilizer can be improved.

The light stabilizer compound of the present invention can be used together with a low viscosity compound for reducing the driving voltage of a liquid crystal composition and having a low viscosity and/or a liquid crystal compound having a high dielectric anisotropy, and in this case, the problem of relatively low stability to light or heat can be solved.

The liquid crystal composition comprising the compound of the present invention has the effects of improving the afterimage level while maintaining stability, securing low-temperature stability, and reducing light leakage phenomenon, and thus can provide a liquid crystal display device optimized for various modes, in particular, a liquid crystal display device of a vertical alignment mode, a polymer stabilized vertical alignment mode, an in-plane switching mode, or a fringe field switching mode.

Drawings

Fig. 1 is a schematic diagram showing the movement path of ions in a device when determining the residual direct current voltage (RDC).

FIG. 2 is a photograph showing a comparison of light leakage phenomenon in the compositions of comparative example 11, example 29, example 30 and example 31.

FIG. 3 is a photograph showing a comparison of light leakage phenomenon in the compositions of comparative example 12, example 32, example 33 and example 34.

The following examples and embodiments of the present invention are described in detail to enable those skilled in the art to easily practice the invention.

The invention may, however, be embodied in many different forms and should not be construed as being limited to the examples and embodiments set forth herein.

Throughout the present specification, when a portion "includes" another structural element, unless otherwise specified, it means that the other structural element may be included, but not excluded. The terms "about," "substantially," and the like, as used throughout this specification to the extent that errors are made in the preparation and materials inherent in the meaning referred to, are used in the meaning of from or near their numerical values to prevent the illicit infringer from unjustly utilizing the disclosure as to whether an exact or absolute numerical value is referred to in order to facilitate an understanding of the present invention.

Throughout the present specification, the term "combination thereof" included in the expression of markush form means a mixture or combination of one or more kinds selected from the group consisting of a plurality of structural elements described in the expression of markush form, and means one or more kinds selected from the group consisting of the above-mentioned plurality of structural elements.

Throughout the present specification, the expression "A and/or B" means "A or B or A and B".

Throughout the present specification, the term "substitutable" or "substituted" may refer to a compound selected from hydrogen, deuterium, oxygen, halogen, amino, nitrile, nitro, silane, alkyl or C₁～C₂₀Alkyl, alkenyl or C₂～C₂₀Alkenyl, alkoxy or C₁～C₂₀Alkoxy, cycloalkyl or C₃～C₂₀Cycloalkyl, heterocycloalkyl or C₃～C₂₀Is heterocycloalkyl or C₅～C₃₀Aryl or C of₅～C₃₀One or more groups of the group consisting of heteroaryl groups of (a) are substituted or unsubstituted.

Also, throughout the present specification, the same reference numerals may have the same meaning unless otherwise specified.

A first embodiment of the present invention provides a light stabilizer compound represented by the following chemical formula 1.

Chemical formula 1

In the above-described chemical formula 1,

R₁and R₂Independently represents hydrogen (H), OH, O, an alkyl group having 1 to 10 carbon (C) atoms or an alkoxy group having 1 to 10 carbon (C) atoms,

R₃to R₅Each independently hydrogen (H), C1-10 linear, branched or cyclic alkyl or C1-10An alkoxy group,

at this time, methylene group (CH)₂) May be substituted by oxygen (O) or vinyl (CH ═ CH),

n is an integer of 0 or 1, and when n is 0, the dotted line may form a solid line.

The light stabilizer compound of the present invention can effectively improve the afterimage of a liquid crystal display device, and can ensure the low temperature stability of a liquid crystal composition due to good solubility.

In one embodiment of the present invention, the above compound may be represented by the following chemical formula 2.

Chemical formula 2

In the above-described chemical formula 2,

R₁to R₄As defined in the above chemical formula 1.

In one embodiment of the present invention, the above compound may be represented by the following chemical formula 2-1.

Chemical formula 2-1

In the above chemical formula 2-1,

R₁and R₂As defined in the above chemical formula 1.

With the chemical formula 2-1, the afterimage improvement effect can be maximized, and the light leakage phenomenon can be greatly reduced. In particular, when R₁、R₂More effective is hydrogen (H), OH, oxygen (O.), or an alkoxy group having 1 to 10 carbon atoms.

In one embodiment of the present invention, the above compound may be represented by the following chemical formula 3.

Chemical formula 3

In the above-mentioned chemical formula 3,

R₁to R₅As defined in the above chemical formula 1.

The compound represented by the above chemical formula 3 is enhanced in Flexibility (Flexibility), and thus, low-temperature stability can be more effectively improved, and a light leakage phenomenon can be improved.

In an example of the present invention, the above compound may include a compound represented by one of the following chemical formulas 3-1 to 3-4.

Chemical formula 3-1

Chemical formula 3-2

Chemical formula 3-3

Chemical formula 3-4

In the above chemical formulas 3-1 to 3-4,

R₁to R₅As defined in the above chemical formula 1.

The compounds represented by the above chemical formulas 3 to 4 may be particularly effective in improving low temperature stability and improving a light leakage phenomenon.

According to an embodiment of the present invention, R is₁And R₂Each independently hydrogen (H), OH or oxygen (O), in which case the afterimage improvement effect can be maximized, and the light leakage phenomenon can be greatly reduced by the compound represented by chemical formula 1, compared to conventional light stabilizers.

The second embodiment of the present invention provides a liquid crystal composition comprising the above-mentioned light stabilizer compound of the present invention.

The liquid crystal composition of an embodiment of the present invention may include the compound represented by the above chemical formula 1 and a plurality of liquid crystal compounds.

As described above, the compound represented by the above chemical formula 1 may be represented by one of the above chemical formula 2, chemical formula 2-1, chemical formula 3, and chemical formula 3-1 to chemical formula 3-4. Also, the liquid crystal composition according to an embodiment of the present invention may include 1 or more compounds represented by the above chemical formula 1.

The light stabilizer compound of the present invention can be used together with a low viscosity compound for reducing the driving voltage and viscosity of a liquid crystal composition and/or a liquid crystal compound having a high dielectric anisotropy, and in this case, the problem of relatively low stability to light or heat can be improved.

According to an example of the present invention, the light stabilizer compound represented by the above chemical formula 1 may be included in 100 parts by weight of the liquid crystal composition in an amount of 0.001 to 1 part by weight, specifically 0.001 to 0.5 part by weight, 0.001 to 0.3 part by weight, 0.003 to 1 part by weight, 0.003 to 0.5 part by weight, or 0.003 to 0.3 part by weight, possibly not limited thereto. The content of the light stabilizer compound may not be contained in 100 parts by weight of the liquid crystal composition.

When the light stabilizer compound represented by the above chemical formula 1 is less than 0.001 parts by weight in 100 parts by weight of the liquid crystal composition, the effect is very slight, and when the light stabilizer compound represented by the above chemical formula 1 is more than 1 part by weight in 100 parts by weight of the liquid crystal composition, the low temperature stability may be weakened, and the effect of improving the light leakage phenomenon due to the reaction of moisture or the alignment film and the light stabilizer may be slight.

According to an embodiment of the present invention, the liquid crystal composition may include 1 or 2 or more compounds represented by the following chemical formula 4.

More specifically, according to an embodiment of the present invention, the liquid crystal composition may include 1 or 2 or more compounds represented by the above chemical formula 1 and the following chemical formula 4.

Chemical formula 4

In the above-mentioned chemical formula 4,

R₇an alkyl group having 1 to 8 carbon (C) atoms, an alkenyl group having 2 to 8 carbon (C) atoms or an alkoxy group having 1 to 8 carbon (C) atoms, in which case the hydrogen (H) atom may be replaced with a halogen,

R₈is alkyl having 1 to 8 carbon (C) atoms, alkenyl having 2 to 8 carbon (C) atoms or alkoxy having 1 to 8 carbon (C) atoms, in which case one or more methylene groups (CH)₂) Each independently of the others, may be composed of-C.ident.C-, -CF-in such a way that oxygen (O) atoms are not directly linked to each other₂O-、-OCF₂-, -CH-, -O-, -CO-O-, -O-CO-or-O-CO-O-, the hydrogen (H) atom may be replaced by halogen,

rings A, B and C are each independently trans-1,4-cyclohexyl (trans-1,4-cyclohexylene) in which the carbon (C) in the ring is substituted by 1 or 2 oxygens (O), trans-1,4-cyclohexyl (trans-1,4-cyclohexylene) in which hydrogen (H) is substituted by 1 fluorine (F), or 1,4-phenylene (1,4-phenylene) in which hydrogen (H) is substituted by 1 fluorine (F),

i and j are each independently an integer of 0, 1 or 2, and when i or j is 2, the phenylene group or the ring C may each be the same or different.

According to an example of the present invention, the compound represented by the above chemical formula 4 may include compounds represented by the following chemical formulas 4-1 to 4-7.

Chemical formula 4-1

Chemical formula 4-2

Chemical formula 4-3

Chemical formula 4-4

Chemical formula 4-5

Chemical formula 4-6

Chemical formula 4-7

In the above chemical formulas 4-1 to 4-7,

R₇and R₈As defined in the above chemical formula 4.

The compound represented by the above chemical formula 4-1 may function to maintain the viscosity of the liquid crystal composition low.

In one example of the present invention, the compound represented by the above chemical formula 4-1 may include compounds represented by the following chemical formulae 4-1-1 to 4-1-4. These compounds may have a particularly useful effect on maintaining the low viscosity of the liquid crystal composition described above.

Chemical formula 4-1

Chemical formula 4-1-2

Chemical formula 4-1-3

Chemical formula 4-1-4

The compound represented by the above chemical formula 4 as a compound having a dielectric anisotropy of about-1 to 3 can provide a liquid crystal composition having a low rotational viscosity and maintaining a wide liquid crystal phase range.

In one example of the present invention, the compound represented by the above chemical formula 4 may be included in an amount of 10 to 75 parts by weight in 100 parts by weight of the liquid crystal composition, and may not be limited thereto. When the amount is less than 10 parts by weight, the liquid crystal composition may exceed the range of the liquid crystal phase or it may be difficult to achieve a low rotational viscosity under normal temperature conditions, and when it exceeds 75 parts by weight, the dielectric anisotropy of the liquid crystal composition may be reduced, thereby making it difficult to adjust the driving voltage of the display.

In particular, as shown in chemical formula 4-1-2, a substance having a double bond at the terminal is a substance weaker than an afterimage due to Ultraviolet (UV). When chemical formula 1 is added to the liquid crystal composition comprising 10 to 75 parts by weight of chemical formula 4-1-2, the afterimage of the composition can be improved.

According to an embodiment of the present invention, the liquid crystal composition may include 1 or 2 or more compounds represented by the following chemical formula 5. In this case, the liquid crystal composition can be adjusted to have positive dielectric anisotropy.

More specifically, according to an embodiment of the present invention, the liquid crystal composition may include 1 or 2 or more compounds represented by the above chemical formula 1 and the following chemical formula 5.

Also, according to an embodiment of the present invention, the liquid crystal composition may include the compound represented by chemical formula 1, 1 or 2 or more compounds represented by chemical formula 4, and 1 or 2 or more compounds represented by chemical formula 5.

Chemical formula 5

In the above-mentioned chemical formula 5,

R₉hydrogen (H), a linear, branched or cyclic alkyl group having 1 to 8 carbon (C) atoms, an alkoxy group having 1 to 8 carbon (C) atoms or an alkenyl group having 2 to 8 carbon (C) atoms, in which case one or more methylene groups CH₂Each independently of the others, may be composed of-C.ident.C-, -CF-in such a way that oxygen (O) atoms are not directly linked to each other₂O-、-OCF₂-, -CH-, -O-, -CO-O-, -O-CO-or-O-CO-O-, the hydrogen (H) atom may be replaced by halogen,

X₁to X₃Each independently hydrogen (H), fluorine (F) or trifluoromethoxy (OCF)₃)，

Y₁Is hydrogen (H) or methyl (CH)₃)，

Rings D to F are each independently trans-1,4-cyclohexyl (trans-1,4-cyclohexylene) in which the carbon (C) in the ring is substituted by 1 or 2 oxygens (O) or 1,4-phenylene (1,4-phenylene) in which hydrogen (H) is substituted by 1 or 2 fluorines (F),

k. l and m are each independently an integer of 0 or 1.

In one example of the present invention, the compound represented by the above chemical formula 5 may include compounds represented by the following chemical formulas 5-1 to 5-18.

Chemical formula 5-1

Chemical formula 5-2

Chemical formula 5-3

Chemical formula 5-4

Chemical formula 5-5

Chemical formula 5-6

Chemical formula 5-7

Chemical formula 5-8

Chemical formula 5-9

Chemical formula 5-10

Chemical formula 5-11

Chemical formulas 5 to 12

Chemical formula 5-13

Chemical formulas 5 to 14

Chemical formula 5-15

Chemical formula 5-16

Chemical formula 5-17

Chemical formulas 5 to 18

In the above chemical formulas 5-1 to 5-18,

R₉as defined in the above chemical formula 5,

(F) refers to hydrogen (H) or fluorine (F).

The compound represented by the above chemical formula 5 is a compound having a positive value of dielectric anisotropy.

In one example of the present invention, the compound represented by the above chemical formula 5 may be included in an amount of 5 to 60 parts by weight in 100 parts by weight of the liquid crystal composition, and may not be limited thereto. When the amount is less than 5 parts by weight, the absolute value of the dielectric anisotropy of the liquid crystal composition is close to 0, and thus it may be difficult to drive the liquid crystal display device, and when the amount is more than 60 parts by weight, the viscosity of the liquid crystal composition increases, and thus the response time of the liquid crystal display device may be slow.

In one embodiment of the present invention, among the compounds represented by the above chemical formula 5, a compound in which m is 1, particularly, chemical formula 5-1 to chemical formula 5-9, is used as a compound having a dielectric anisotropy of 20 or moreThese are essential for liquid crystal compositions having positive dielectric anisotropy. This has CF₂Many substances of the O linker are chemically unstable, and may cause afterimage for a long period of time. Therefore, in the above chemical formula 5, when chemical formula 1 is added to the liquid crystal composition containing 5 to 60 parts by weight of the liquid crystal compound in which m is 1, the afterimage can be more improved.

According to an embodiment of the present invention, the liquid crystal composition may include 1 or 2 or more compounds represented by the following chemical formula 6. In this case, the liquid crystal composition can be adjusted to have a negative dielectric anisotropy.

More specifically, according to an embodiment of the present invention, the liquid crystal composition may include 1 or 2 or more compounds represented by the above chemical formula 1 and the following chemical formula 6.

Also, according to an embodiment of the present invention, the liquid crystal composition may include the compound represented by chemical formula 1, 1 or 2 or more compounds represented by chemical formula 4, and 1 or 2 or more compounds represented by chemical formula 6.

Chemical formula 6

In the chemical formula 6 described above,

R₁₀and R₁₁Each independently is an alkyl group having 1 to 8 carbon (C) atoms, an alkenyl group having 2 to 8 carbon (C) atoms or an alkoxy group having 1 to 8 carbon (C) atoms, in which case, one or more methylene groups (CH)₂) Each independently of the others, may be composed of-C.ident.C-, -CF-in such a way that oxygen (O) atoms are not directly linked to each other₂O-、-OCF₂-, -CH-, -O-, -CO-O-, -O-CO-or-O-CO-O-, the hydrogen (H) atom may be replaced by halogen,

rings G, H and I are each independently trans-1,4-cyclohexyl (trans-1,4-cyclohexylene) in which the carbon (C) in the ring is substituted by 1 or 2 oxygens (O) or 1,4-phenylene (1,4-phenylene) in which hydrogen (H) is substituted by 1 or 2 fluorines (F),

Z₁is a single bond, -CH₂O-、-OCH₂-、-CH₂CH₂-、-CF₂O-or-OCF₂-，

n, o and p are each independently an integer of 0 or 1.

In one example of the present invention, the compound represented by the above chemical formula 6 may include compounds represented by the following chemical formulas 6-1 to 6-11.

Chemical formula 6-1

Chemical formula 6-2

Chemical formula 6-3

Chemical formula 6-4

Chemical formula 6-5

Chemical formula 6-6

Chemical formula 6-7

Chemical formula 6-8

Chemical formula 6-9

Chemical formula 6-10

Chemical formula 6-11

In the above chemical formulas 6-1 to 6-11,

R₁₀and R₁₁As defined in the above chemical formula 6.

The compound represented by the above chemical formula 6 is a compound having a negative value of dielectric anisotropy.

According to an example of the present invention, the compound represented by the above chemical formula 6 may be included in an amount of 5 to 85 parts by weight in 100 parts by weight of the liquid crystal composition, possibly without being limited thereto. When the amount is less than 5 parts by weight, the absolute value of the dielectric anisotropy of the liquid crystal composition is close to 0, and thus it may be difficult to drive the liquid crystal display device, and the rotational viscosity of the liquid crystal composition having a high dielectric anisotropy is high, so that it may be difficult to drive the liquid crystal display device at a low voltage. When the amount is more than 85 parts by weight, the viscosity of the liquid crystal composition increases, and the response time of the liquid crystal display device may be reduced.

According to an embodiment of the present invention, when R₁₁Such as-OCH₃、-OC₂H₅、-OC₃H₇、-OC₄H₉In the case of alkoxy groups, they are useful for preparing liquid crystal compositions having negative dielectric anisotropy. However, the alkoxy liquid crystal compound bonded to the phenylene group is weaker than the residual image. Therefore, when chemical formula 1 is added to a liquid crystal composition containing 5 to 85 parts by weight of such a substance, afterimages can be improved.

In one embodiment of the present invention, the liquid crystal composition may include 1 or 2 or more antioxidants represented by the following chemical formula 7. More specifically, the liquid crystal composition having the positive dielectric anisotropy or the liquid crystal composition having the negative dielectric anisotropy may further include an antioxidant represented by the following chemical formula 7.

Chemical formula 7

In the chemical formula 7 described above,

R₁₂is an alkyl group having 1 to 12 carbon (C) atoms,

ring J is trans-1,4-cyclohexyl (trans-1, 4-cyclohexene), tetrahydropyran (tetrahydropyran) or dioxane (dioxane),

q is an integer of 0, 1 or 2, and when q is 2, the rings J may be the same or different.

In one example of the present invention, the antioxidant represented by the above chemical formula 7 may be represented by the following chemical formula 7-1 or chemical formula 7-2.

Chemical formula 7-1

Chemical formula 7-2

In one example of the present invention, the antioxidant represented by the above chemical formula 7 may be included in an amount of 0.005 to 0.05 parts by weight in 100 parts by weight of the liquid crystal composition. When the amount is less than 0.005 parts by weight, the effect of suppressing the chain reaction of the radical species due to the aging of the liquid crystal compound is very small, and when the amount is more than 0.05 parts by weight, the stability to ultraviolet rays is weakened, and there is a possibility that a Voltage Holding Ratio (VHR) which is one of important characteristics of the liquid crystal display device is lowered. The liquid crystal composition may not contain an antioxidant in an amount of 100 parts by weight.

A third embodiment of the present invention provides a liquid crystal display device comprising the liquid crystal composition of an example of the present invention.

The structure of the liquid crystal display device is not particularly limited and may have a structure generally used in the art. The liquid crystal layer of the liquid crystal display device may include the liquid crystal composition of an example of the present invention.

As described above, the liquid crystal composition containing the light stabilizer compound of the present invention can have an afterimage-improving effect, low temperature stability. Also, the liquid crystal composition of an embodiment of the present invention may include a low viscosity compound and/or a liquid crystal compound having a high dielectric anisotropy.

Also, the liquid crystal composition of an example of the present invention can be used for liquid crystal display devices of various modes, in particular, a vertical alignment mode, a polymer stabilized vertical alignment mode, an in-plane switching mode, or a fringe field switching mode.

Hereinafter, the operation and effect of the present invention will be described in more detail with reference to specific examples of the present invention. It is only proposed as an exemplification of the invention, which is not intended to limit the scope of the claims in any way. In the examples and comparative examples, the structures of the compounds contained in the liquid crystal compositions were classified into a center group, a connecting group, and an end group, and the structures are represented by symbols in the following table 1.

TABLE 1

Examples

Properties of the light stabilizer compound represented by chemical formula 1 of the present invention and evaluation of the mother liquid Crystal

(1) Determination of the clearing Point

After placing a liquid crystal composition in a capillary having a diameter of 1mm and mounting the capillary on a Mettler TOLEDO (METTLER TOLEDO) MP50, the transmittance was observed while raising the temperature at a gap of 3 ℃/min. The point where the transmittance sharply increases is defined as a transparent point by an optical change.

(2) Stability at Low temperature

A liquid crystal composition prepared by mixing a mother liquid crystal and 0.1 part by weight of a compound represented by chemical formula 1 per 100 parts by weight of the mother liquid crystal was charged into a 10mL vial 2g and stored in a freezer at-25 ℃. Whether recrystallization occurred or not was confirmed every 1 day. The liquid crystal composition in the example according to the storage time confirmation of recrystallization cases are expressed as NG.

(3) Anisotropy of refractive index

The liquid crystal was aligned with lecithin by measurement at 589nm using an Abbe refractometer, and after that, the extraordinary refractive index and the ordinary refractive index were confirmed under a condition of 20 degrees to obtain refractive index anisotropy.

(4) Dielectric anisotropy

The dielectric anisotropy (Δ ∈) of the liquid crystal composition was calculated by substituting ∈/, and ∈ ⊥ measured as follows into the following formula 1.

Formula 1

Δε＝ε∥-ε⊥

① measurement of dielectric constant ε/the dielectric constant (. epsilon. /) of the device at 1kHz, 0.3V and 20 ℃ was measured by using a cell having a cell thickness of 4 μm and a liquid crystal composition as a measurement object, which was injected into a cell having a cell thickness of a vertical alignment agent coated on the surface of an Indium Tin Oxide (ITO) pattern on which two glass substrates were formed, and using a 4294A apparatus prepared by Agilent.

② measurement of dielectric constant ε ⊥ the dielectric constant (. epsilon. ⊥) of a device at 1kHz, 0.3V and 20 ℃ was measured by using a cell box having a cell thickness of 4 μm and prepared by applying a horizontal alignment agent to the surface of an indium tin oxide pattern on which two glass substrates were formed, injecting a liquid crystal composition to be measured, and using ultraviolet light in a 4294A apparatus prepared by Agilent.

(5) Rotational viscosity

After a liquid crystal composition as an object of measurement was injected into a test cell cartridge having a cartridge thickness of 20 μm and mounted on a temperature controller (controller) (Model (SU) 241) of estpec Corp, the rotational viscosity of this test cell cartridge was measured by measuring a peak time (peak current) and a peak current (peak current) of a transient current (transient current) at a temperature of 20 ℃ using a Model 6254 device of Toyo Corp.

(6) Modulus of elasticity

After injecting the liquid crystal composition as an object of measurement into a cell of a test cell having a cell thickness of 20 μm, the elastic modulus was obtained by a change in electric capacity while applying a voltage from 0V to 20V. Where K11 denotes the splay (splay) elastic modulus and K33 denotes the bend (band) elastic modulus. The measurement temperature was 20 ℃.

(7) Residual direct current voltage (RDC, Residual DC)

A horizontal alignment film was formed by applying a horizontal alignment agent (a vertical alignment agent is used when measuring a liquid crystal having a negative dielectric anisotropy) to the surface of the indium tin oxide pattern on which the two glass substrates were formed. Next, the surfaces of the two glass substrates coated with the horizontal alignment films were rubbed, a spacer was applied to one of the two glass substrates so that the horizontal alignment films were opposed to each other and the gap (cell thickness) between the two glass substrates was 3 μm, and then the two glass substrates were bonded so that the rubbing directions were Antiparallel (anti parallel) to each other to prepare a device. Then, a liquid crystal composition is injected into the device, and the device is sealed with an adhesive cured by ultraviolet rays. Thereafter, the residual voltage (RDC) of the above device was measured at a temperature of 60 ℃ using a Model 6254 device of Toyo corporation equipped with a temperature controller (Model SU-241) prepared in Espeek corporation. The residual voltage (RDC, Vsat) is a voltage measured 1 minute after 15V charging (charging), 1 second after discharging (discharging), and 1000 seconds after the elapse. Fig. 1 is a schematic diagram showing the movement path of ions in the above device when RDC is measured.

(8) Light leakage phenomenon

A horizontal alignment agent whose alignment direction is determined by ultraviolet rays is applied to the surface on which the indium tin oxide patterns of the two glass substrates are formed, thereby forming a horizontal alignment film. Next, the surfaces of the two glass substrates coated with the horizontal alignment films were irradiated with ultraviolet rays to set the alignment direction, and a spacer was applied to one of the two glass substrates so that the horizontal alignment films were opposed to each other and the gap (cell thickness) between the two glass substrates was 2.8 μm, and then the two glass substrates were bonded so that the alignment directions were parallel to each other. Then, the liquid crystal composition was injected into the device, and the device was stored in a 85 ℃ temperature and 85% humidity Chamber (Chamber) without sealing the injection port, and then the injection port of the device was observed by a polarization microscope the next day. In the observation, the polarizers above and below the device were set at 90 degrees, and light leakage was observed with a microscope of 20 magnifications.

(9) Preparation of mother liquid crystals

In order to evaluate the characteristics of the light stabilizer compound represented by chemical formula 1 of the present invention, mother liquid crystals having the structures of the following tables 2 to 5 were used, and the encoded symbols were marked by the method of the above table 1. The contents in tables 2 to 9 are parts by weight.

TABLE 2

TABLE 3

TABLE 4

TABLE 5

TABLE 6

TABLE 7

TABLE 8

TABLE 9

The compound represented by chemical formula 1 evaluated in this example was specifically substance X, Y, Z of the following table 6, and on-market stabilizer Tianchenghui (Tinuvin)770(T-770) was evaluated as a comparative substance.

Watch 10

Synthesis example 1: synthesis of substance X

The substance X can be synthesized by the following reaction formula 1, but is not limited thereto.

Reaction scheme 1

In a reaction vessel equipped with a stirrer, a thermometer, a cooling tube and a Dean Stark tube, 15.0g (0.075mol) of diethyl 2- (propan-2-ylidene) malonate125.9g (0.166mol) of 4-hydroxy-2, 2,6, 6-tetramethylpiperidine2And 0.19g (0.763mmol) of dibutyltin oxide were dissolved in xylene (60mL), and the mixture was refluxed for 48 hours under a nitrogen atmosphere. Methanol produced en route is separated by dean stark. After cooling at room temperature, the reaction solution was diluted with water and dichloromethane, and the phases were separated. After that, the organic layer was extracted, washed with distilled water, and dried over magnesium sulfate. Using dissolved n-heptane: ethyl acetate ═ 1: 1. eluting with 5 wt% triethylamine in silica gel column to obtain compoundX(21.3g, 65% yield). GC-MS (EI): m/z 422[ M + H +]Melting point: 101 deg.C

Synthesis example 2: synthesis of substance Y

The substance Y can be synthesized by the following reaction formula 2, but is not limited thereto.

Reaction formula 2

In a reaction vessel equipped with a stirrer, a thermometer, a cooling tube and a Dean Stark tube, 5.0g (0.025mol) of diethyl 2-isopropane malonate was placed38.5g (0.054mol) of 4-hydroxy-2, 2,6, 6-tetramethylpiperidine2And 0.06g (0.241mmol) of dibutyltin oxide were dissolved in xylene (25mL), and the mixture was refluxed for 48 hours under a nitrogen atmosphere. Methanol produced en route is separated by dean stark. At room temperatureAfter cooling, the reaction solution was diluted with water and dichloromethane, and the phases were separated. After that, the organic layer was extracted, washed with distilled water, and dried over magnesium sulfate. Using dissolved n-heptane: ethyl acetate ═ 1: 1. eluting with 5 wt% triethylamine in silica gel column to obtain compoundY(10.3g, 58% yield). GC-MS (EI): m/z 424[ M + H +]Melting point: 52.3 deg.C

Synthesis example 3: synthesis of substance Z

The substance Z can be synthesized by the following reaction formula 3, but is not limited thereto.

Reaction formula 3

25.8g (0.119mol) of diethyl 2-isopropyl-2-methylmalonate was placed in a reaction vessel equipped with a stirrer, a thermometer, a cooling tube and a Dean Stark tube441.2g (0.264mol) of 4-hydroxy-2, 2,6, 6-tetramethylpiperidine2And 2.7g (0.01mol) of dibutyltin oxide were dissolved in xylene (130mL) and heated under reflux under a nitrogen atmosphere for 72 hours. Methanol produced en route is separated by dean stark. After cooling at room temperature, the reaction solution was diluted with water and dichloromethane, and the phases were separated. After that, the organic layer was extracted, washed with distilled water, and dried over magnesium sulfate. Using dissolved n-heptane: ethyl acetate ═ 1: 1. eluting with 5 wt% triethylamine in silica gel column to obtain compoundZ(31.1g, 59% yield). GC-MS (EI): m/z 438[ M + H +]Melting point: 73.2 deg.C