WO2005042670A1

WO2005042670A1 - Nematic liquid crystal composition and liquid crystal display device using same

Info

Publication number: WO2005042670A1
Application number: PCT/JP2004/015909
Authority: WO
Inventors: Yousuke Akachi; Takeshi Kuriyama
Original assignee: Dainippon Ink And Chemicals, Inc.
Priority date: 2003-10-30
Filing date: 2004-10-27
Publication date: 2005-05-12
Also published as: TW200528597A; TWI358448B; CN1875083A; KR101060207B1; CN1875083B; KR20060095570A

Abstract

Disclosed is a nematic liquid crystal composition which is characterized by containing one or more kinds of at least one of a semipolar organic boron compound and a charge-transfer complex composed of a semipolar organic boron compound, and by having a resistivity of not less than 1.0 × 1011 Ω·cm and not more than 1.0 × 1013 Ω·cm. Also disclosed is a liquid crystal display device using such a nematic liquid crystal composition.

Description

Specification

Nematic liquid crystal composition and liquid crystal display device using the same

Technical field

The present invention relates to a nematic liquid crystal composition and a liquid crystal display device using the same.

Background art

[0002] In a process of manufacturing a liquid crystal display element such as a twisted nematic, a super twisted nematic, an active matrix, or the like, when the protective film attached to the surface of the liquid crystal display element is peeled off, an electric field due to static electricity (peeling) is present in the element. (Electrification) occurs. This electric field often orients the liquid crystal composition in the non-lighted parts, ie, the non-lighted parts are turned on, and the alignment continues until the electric field is discharged. The time required for this electric field to be discharged cannot be ignored, and it may be necessary to suspend the work not only in the manufacturing process but also in the inspection process or the shipping process such as the work to wipe off the dirt on the element surface. As a result, extra time (production time per product) may be reduced.

[0003] It is disclosed that the problem of abnormal alignment due to charging can be mitigated by lowering the specific resistance of the liquid crystal composition (see Patent Document 1). The liquid crystal composition having a low specific resistance value has a low specific resistance, so that even if a temporary voltage is applied due to charging due to static electricity or the like, the charge is rapidly discharged, and the liquid crystal molecules are discharged when no voltage is applied. The orientation state can be restored. For example, the specific resistance value of a general liquid crystal composition in a nematic liquid crystal display element is 1 X ΙΟ ^ Ω 'cm or more.The relaxation time of liquid crystal molecules with respect to the application of a temporary voltage due to charging is large. Pretty long,. When a substance that lowers the specific resistance is added to the composition to lower the specific resistance to the order of 1 × 10 ⁹ Ω'cm, the charge relaxation becomes very fast. Therefore, even if a temporary voltage is applied due to charging due to static electricity or the like, a change in alignment state can hardly be confirmed. However, the liquid crystal display element using a liquid crystal material having a specific resistance lower than 1 × 10 ¹⁰ Ω'cm often causes an increase in power consumption, and furthermore, a defect such as burning of characters due to an electric short circuit. May cause display. Therefore, a liquid crystal composition having a moderately large specific resistance value and having improved behavior with respect to the temporary application of a voltage due to charging of the liquid crystal display element due to static electricity or the like, that is, due to static electricity or the like. There is a need for the development of a liquid crystal composition in which the relaxation of the liquid crystal molecules is sufficiently fast with respect to the application of a temporary voltage due to the charging.

[0004] As a method of relaxing the abnormal alignment of liquid crystal molecules due to static electricity or the like in the above-described liquid crystal composition, for example, a method of adding an ionic substance such as Cryptand to the liquid crystal composition has been disclosed ( Patent Document 2). However, the ionic component in the liquid crystal composition is adsorbed by a polymer film such as polyimide in a liquid crystal display element at a part of an injection port of a liquid crystal panel, which often causes display unevenness. Had the problem of becoming

[0005] Similarly, as a method for relaxing abnormal orientation of liquid crystal molecules due to static electricity or the like, a method of adding a nonionic surfactant such as ethylene glycol and a copolymer thereof has been disclosed (Patent Reference 3). However, in this method, due to the mechanism of antistatic, the effect is affected by the amount of ions in the liquid crystal and the orientation film and the orientation state, and there is a case where a sufficient antistatic effect cannot be obtained immediately. In addition, if a large amount is added in order to sufficiently obtain the effect, the nematic isotropic phase transition temperature (liquid crystal phase transition temperature) When the upper limit temperature was greatly reduced, there was a problem.

[0006] Similarly, a method of adding a so-called crown ether such as a cyclic polyether has been disclosed as a method of alleviating abnormal orientation of liquid crystal molecules due to static electricity or the like (Patent Document 4). However, crown ethers have a strong effect on human skin or eyes, such as severe irritation, and may cause problems in the working environment in the manufacture of liquid crystal display devices! Have /!

[0007] Furthermore, when the above-mentioned conventional non-liquid crystalline compound is added, there are problems such as poor compatibility with other liquid crystal compounds and loss of liquid crystal properties. In addition, no additive has been found that can rapidly alleviate the abnormal alignment of liquid crystal molecules upon application of a temporary voltage due to charging by static electricity or the like without lowering the specific resistance and display quality.

Patent Document 1: Japanese Patent Application Laid-Open No. 59-4676 (page 2)

Patent Document 2: Japanese Patent Application Laid-open No. Hei 4 28788 (2 pages) Patent Document 3: JP-A-4-180993 (page 4)

Patent Document 4: Japanese Patent Publication No. Hei 11 508286 (2 pages)

Disclosure of the invention

Problems to be solved by the invention

[0008] An object of the present invention is to provide a liquid crystal display element having a moderately large specific resistance value without using a material that significantly lowers the specific resistance and the upper limit temperature of the liquid crystal phase, and temporarily causing a liquid crystal display element to be charged due to static electricity or the like. An object of the present invention is to provide a liquid crystal composition capable of promptly relieving abnormal alignment of liquid crystal molecules upon application of a specific voltage.

Means for solving the problem

[0009] The inventors of the present application have studied a semipolar organic boron compound or a nematic liquid crystal composition containing a charge transfer complex formed using the semipolar organic boron compound. The inventors have found that the present invention has an effect of promptly relaxing the abnormal orientation, and have completed the present invention.

That is, the invention of the present application contains at least one kind of a semipolar organic boron compound and a charge transfer complex composed of the semipolar organic boron compound, and the boron atom in one molecule of the semipolar organic boron compound is contained. And a liquid crystal display using the nematic liquid crystal composition, wherein the specific resistance value is not more than 5 and the specific resistance value is not less than 1.0Ο10 ¹⁰ Ω-cm and not more than 1.0Χ10 ¹³ Ω'cm. An element is provided.

The invention's effect

[0010] The nematic liquid crystal composition of the present invention has a moderately large! / ヽ specific resistance value, and quickly alleviates abnormal alignment of liquid crystal molecules due to temporary application of voltage due to charging due to static electricity or the like. Has features. Due to this feature, it is possible to shorten the discharge time of the charge caused by the charging in the manufacturing process, and to efficiently manufacture the liquid crystal display element.

Brief Description of Drawings

FIG. 1 is a diagram showing an example of the structure of an electro-optical element according to the present invention.

Explanation of symbols

[0012] 1 Polarizing plate 2 Board

3 Transparent electrode or transparent electrode with active element

4 Alignment film

5 LCD

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, an example of the present invention will be described. However, the present invention is not limited to the following examples. For example, the components of these examples may be appropriately combined. The present invention relates to a nematic liquid crystal composition having improved behavior due to the application of a temporary voltage due to charging by static electricity or the like, and a liquid crystal display device using the same.

In the present invention, the nematic liquid crystal composition contains one or more semipolar organic boron compounds or a charge transfer complex composed of the semipolar organic boron compound. It may contain either force of the compound or the complex, or both. As a result, it is possible to improve the time for relaxing the abnormal alignment of the liquid crystal molecules when a temporary voltage is applied due to charging of the liquid crystal display element due to static electricity or the like, as compared with the conventional liquid crystal composition.

[0014] The semipolar organic boron compound generally refers to an organic boron compound having a semipolar bond. Because boron is trivalent, it forms a bond with three oxygen atoms when forming boric acid derivatives. However, the boron atom has an empty electron orbital, and a lone electron pair such as an oxygen atom coordinates to this orbital to stabilize it with a special structure bonded to four oxygen atoms. Since this coordination bond is called a semipolar bond, an organic boron compound having a semipolar bond is generally called a semipolar boron compound. The term semipolar organoboron compound used in the present invention is also used in this meaning.

[0015] The semipolar organic boron compound to be added to the liquid crystal composition of the present invention includes di (glycerin) borate, di (glycerin) borate monovalent carboxylic acid ester, di (catechol) borate, di (1 , 2-propylene glycol) borate, di (2-ethyl-1,3-hexanediol) borate or a compound having a skeleton represented by the following general formula (I) is preferred. [0016] [Formula 1]

— CHO OHC—

(I)

—CHO ', C¾C- The above compounds may be used alone or in combination of two or more. In consideration of the compatibility with the liquid crystal composition, the number of boron atoms contained in one molecule is preferably one. More specifically, the semipolar organoboron compound has the following general formula (I-

The compound represented by 1) or the general formula (1-2) is preferable. The compounds represented by these general formulas may be used alone or in combination as needed.

[0017] [Formula 2]

(Wherein, R ¹ and R ² are each independently a hydrogen atom, a hydroxyl group, an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, an alkenyl group having 2 to 12 carbon atoms, C2 to C12 alkenyl group, C1 to C12 alkyl group substituted by halogen, C1 to C12 alkoxy group substituted by halogen, C2 to C12 substituted by halogen alkenyl group or Aruke from been 2 carbon atoms substituted by halogen 12 - represents a Ruokishi group, in each a ¹ and a ² are independently a single bond, an alkylene group having 1 to 10 carbon atoms, from 6 to 18 carbon atoms Aryl group, — (one (CH) O—) (n is from 1

2 n m

M represents an integer of 1 to 30, and m represents an integer of 1 to 30. ), CH— O— CO— R ³ — CO— (R ³ is

2

Represents a hydrocarbon group having 1 to 60 carbon atoms. ) Or ^{CH- O- CO- NH- R 3 - NH-} CO

2

Represents —, and p and q each independently represent an integer from 1 to 10. When there are a plurality of forces A ¹ and A ² , they may be the same or different. )

The content of the semipolar organoboron compound contained in the liquid crystal composition is preferably in the range of 0.00001 to 1% by mass, and more preferably in the range of 0.1% by mass to 0.0001%.

The liquid crystal composition of the present invention has a specific resistance of 1.0 X 10 ^{1 (>} Ω 'cm or more 1.0 X 10 ¹³ Ω-cm It is the following, but the lower limit is 1. Ο Χ ΙΟ ^ Ω 'cm or more is preferred. The upper limit is 1.0 Χ 10 ¹² Ω • cm or less is preferred. !. 0Χ10 ¹² Ω · «η or less is more preferable.

The above-mentioned semipolar organoboron compound has a property of easily becoming an electron donor, and forms a charge transfer complex in combination with an appropriate electron acceptor. The charge-transfer complex composed of the semipolar organic boron compound also has an effect of rapidly relaxing abnormal alignment of liquid crystal molecules to a temporary application of a voltage due to charging by static electricity or the like.

[0021] In order to form the charge transfer complex used in the present invention, a semipolar organoboron compound serving as an electron acceptor and an electron donor are required. Preferred electron donors are fulvalene derivatives such as tetrathiofulvalene and tetraselenofulvalene, and phthalocyanines and their derivatives, amine compounds, hydroquinones, and other amine compounds. Amine compounds include those classified into aliphatic amine compounds and aromatic amine compounds. And poly (ethyleneimino) and its ethylene oxide adduct, polyvinylpyridine, poly (dimethylaminoethyl) acrylate, poly (dimethylaminopropyl) acrylamide, and diallylamine-isobutylene alternating copolymer. These may be used alone or in combination as needed.

[0022] The content of the charge-transfer complex composed of these semipolar organic boron compounds in the liquid crystal composition is preferably in the range of 0.00001 to 1% by mass. Is more preferable.

The nematic liquid crystal composition of the present invention preferably contains one or two or more compounds represented by the following general formula (II), preferably 1 to 20 and more preferably 1 to 15. preferable. [0023]

(Wherein, R ⁴ is a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, an alkyl group having 1 to 12 carbon atoms substituted by at least one halogen, an alkyl group having 2 to 12 carbon atoms) Represents a group or an alkyl group having 2 to 12 carbon atoms substituted by at least one halogen, and one or more CH groups present in these groups each independently represent an O original

2

Oxygen atoms, sulfur atoms, CO COO— OCO— or OCO o—, provided that the atoms are not directly bonded to each other,

B ¹ and B ² are each independently a trans 1,4-cyclohexylene group (one CH group or two non-adjacent CH groups present in this group is substituted with an oxygen atom or a sulfur atom)

twenty two

It may be replaced. ), 1,4-phenylene group (one or two or more CH groups present in this group may be substituted by a nitrogen atom), 1,4-cyclohexene-lene group, 1,4 -Bicyclo [2.2. 2] otathylene group, piperidine-1,4-diyl group, naphthalene 2,6-diyl group, decahydronaphthalene-1,6-diyl group or 1,2,3,4-tetrahydro Naphthalene represents a 1,6-diyl group, and the hydrogen atom present in these groups may be replaced by a methyl group, CN or halogen. S and t are each independently 01 or 2 Where the sum of s and t is 3 or less,

Z ¹ and Z ² are independently CH CH CH = CH — CH (CH) CH CH

2 2 3 2 2

CH (CH) CH (CH) CH (CH) CF CF CF = CF CH O O

3 3 3 2 2 2

CH OCH (CH) CH (CH) 0 CH) (CH) O 0 (CH)

2 3 3 2 4 2 3 2 3 C≡C CF O OCF COO OCO COS SCO or

twenty two

Represents a join,

L ¹ and L ³ each independently represent a HF or C1, L ² is, F Cl CN - CF Z ¹ and Z ² are double

When there are numbers, they may be the same or different. ) [0025] The content of the compound represented by the general formula (II) in the liquid crystal composition is preferably in the range of 1 to 80% by mass, more preferably 1 to 50% by mass, 1 to 20. % By weight is particularly preferred.

In the general formula (II), R ⁴ preferably represents an alkyl group having 1 to 12 carbon atoms, an alkoxy group, an alkenyl group having 2 to 12 carbon atoms, or an alkenyl group having 2 to 12 carbon atoms. Further preferred are straight-chain alkyl groups and straight-chain alkyl groups. It is preferred that the structural force represented by Formula Group 1 be independently selected for B ¹ and B ² .

[0026] [Formula 4]

More preferably, B ¹ and B ² are each independently selected from the structural members represented by Formula Group 2. [0027] [Formula 5]

In the general formula (II), Z ¹ and Z ² are each independently a single bond, CH CH CH (C

twenty two

H) CH -CH CH (CH) CH (CH) CH (CH) C≡C COO

3 2 2 3 3 3

Preferably represents one OCO—, a single bond, —CH CH—C≡C—COO— or one

twenty two

A single bond or COO—, in which OCO is more preferred, is particularly preferred. L ¹ and L ³ each independently, F CN -CF or preferably fixture F or CN to represent OCF is especially

3 3

Preferred. As for s and t, it is preferable that s + t represents 1 or 2. The compound represented by the general formula (II) includes, specifically, the general formula (11-1), the general formula (11-2), the general formula (11-3), the general formula (Π-4), The compound represented by the formula (11-5), the general formula (11-6), the general formula (11-7), or the general formula (Π-8) is preferable.

[0029] [Idori 6]

(Wherein, L ¹ and L ³ each independently represent HF or C1, and L ² represents F Cl, —CN, —CF, —OCH F, —OCHF OCF or CH CF Represents X ¹ and X

3 2 2 3 2 3

Each independently represents Η or F. )

The nematic liquid crystal composition preferably further contains one or more compounds represented by the following general formula (III), and preferably contains 1 to 20 compounds. Species are more preferred.

[0031] [Formula 7]

(Wherein, R ⁵ and R ⁶ have the same meaning as R ⁴ in the general formula (II),

C ² and C ^{3 each} independently represent a trans 1,4-cyclohexylene group (one CH group or adjacent to the trans 1,4-cyclohexylene group, wherein two CH groups are an oxygen atom or It may be replaced with a sulfur atom! ヽ

twenty two

. ), 1,4-phenylene group (one or more CH groups present in this group may be substituted by nitrogen atoms), 1,4-cyclohexene-lens, 4-bicyclo [2.2.2] octylene, piperidine 1,4-diyl, naphthalene 2,6-diyl, decahydronaphthale Represents a 2,6-diyl group or 1,2,3,4-tetrahydronaphthalene-2,6-diyl group, and the hydrogen atoms present in these groups are replaced by methyl, CN or halogen. U, V and w each independently represent 0 or 1,

Z ³ , Z ⁴ and Z ⁵ are each independently CH CH CH = CH-,-CH (CH) CH

2 2 3 2 CH CH (CH) CH (CH) CH (CH) CF CF CF = CF CH

2 3 3 3 2 2

O -OCH OCH (CH) CH (CH) 0 (CH) (CH) O

2 2 3 3 2 4 2 3

O (CH) C≡C -CF O -OCF COO OCO COS SC

2 3 2 2

O CH = N— N = CH— or a single bond. )

The content of the compound represented by the general formula (III) is preferably in the range of 5 to 95% by mass, more preferably in the range of 10 to 90% by mass, and still more preferably in the range of 25 to 90% by mass. Better.

In the general formula (III), R ⁵ and R ⁶ are each independently an alkyl group having 1 to 12 carbon atoms, an alkoxy group, an alkenyl group having 2 to 12 carbon atoms, or an alkenyl group having 2 to 12 carbon atoms. It preferably represents a group, and among them, a linear alkyl group and a linear alkenyl group are more preferable.

For C ² and C ^3, it is preferable that the structural force represented by the following formula group 3 is also selected, and it is more preferable that the structural force represented by the following formula group 4 is also selected.

[0034] [Formula 8]

[0035]

Z ³ Z ⁴ and Z ⁵ in the general formula (III) are each independently a single bond, -CH CH-CH =

twenty two

CH -CH (CH) CH CH CH (CH) CH (CH) CH (CH) — C≡C

3 2 2 3 3 3 A single bond, preferably representing one COO— — OCO— or one CH = N— N = CH—, one CH CH -CH = CH- one C≡C one COO OCO— or ί Maichi CH = N— N = CH—

twenty two

Is more preferred. u V and w are each independently 0 or 1, and Although the sum is 1 or more, the sum of uv and w is preferably 2 or 3. The general formula (III) is specifically represented by the following general formula (111-1), general formula (111-1), general formula (ΙΠ-3), general formula (111-4), general formula (111-4) It is preferable to be a compound represented by 5), general formula (ΙΠ-6), general formula (ΙΠ-7), or general formula (ΙΠ-8).

[Formula 10]

(Wherein, R ⁵ has the same meaning as R ⁴ in general formula (II);

Υ ² Υ. And Upsilon ⁴ is, their respective independent represent Eta F or a methyl group, Zeta ⁷ is, -CH CH CH = CH- -

twenty two

COO OCO— or a single bond, 、 ⁸ 、, C≡C COO OCO— or CH CH = N— N = CH—. )

[0039] From the general formula (から -1) to the general formula (III-8),

Υ ³ and Υ ⁴ are preferably —Η! / ヽ ο Ζ ⁷ is preferably —CH CH— CH = CH— or a single bond. Z ⁸ is C≡C—or 1 C

twenty two

H = N-N = CH—is preferred! / ヽ.

The maximum temperature of the nematic phase of the liquid crystal composition of the present invention is preferably 60 ° C or higher, more preferably 80 ° C or higher, and particularly preferably 90 ° C or higher.

The refractive index anisotropy (Δη) is preferably in the range of 0.06 to 0.30 0.07 to 0.3.

A range of 18 is more preferable, but in the case of ΤΝ—LCD, the range of 0.07 to 0.16 is particularly preferable in the cell thickness design. For STN—LCD, a range of 0.12 to 0.18 It is particularly preferred in terms of cell thickness design.

The dielectric anisotropy (Δε) is preferably 1 or more and 20 or less, more preferably 1 or more and 15 or less. Yes.

[0041] The liquid crystal composition of the present invention may optionally contain a normal nematic liquid crystal, a smectic liquid crystal, a cholesteric liquid crystal, a dichroic dye, and the like, in addition to the above compounds. A chiral agent may be added to prevent reverse twist domains of TN LCD and to induce a helical structure of STN-LCD. Commercially available chiral agents can be used. For example, cholesteryl nonanoate (CN), S-811, R-811, CB-15, C15, etc., manufactured by Merck Ltd. are mentioned. It is known that, depending on the type of chiral agent, the induced helical pitch becomes longer and shorter as the temperature rises. One of these may be used alone or two or more may be used. Yes, two or more types may be used. For example, in TN-LCD, STN-LCD and TFT-LCD, the quotient dZp of the thickness d between the substrates and the induced helical pitch P is in the range of 0.001 to 24. The range is preferred 0.1 The range of 1 to 2 is more preferred 0.1 The range of 1 to 1.5 is even more preferred, the range of 0.1 to 1 is even more preferred 0.1 to 0 A range of 8 is particularly preferred.

[0042] The above nematic liquid crystal composition is useful for TN-LCD, STN-LCD, OCB-LCD, polymer dispersion type liquid crystal display device, phase change type cholesteric liquid crystal display device, etc., but TN-LCD, STN-LCD Especially useful for: Further, it can be used for a transmissive or reflective liquid crystal display element.

In the TN liquid crystal display element of the present invention, the twist angle can be selected in the range of 80 ° and 130 ° according to the purpose, and the 85 ° force is preferably 110 °. In the STN liquid crystal display device of the present invention, the twist angle can be selected from a range of 180 ° and a force of 270 °, preferably from 220 ° to 260 °, according to the purpose.

Example 1

Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples. In the following examples and comparative examples, “%” in the yarn composition means “% by mass”.

The characteristics measured in the examples are as follows.

T: Nematic phase isotropic liquid phase transition temperature (° C)

N-I

Δ ε: dielectric anisotropy (25 ° C) Δ η: birefringence (25 ° C)

P: Specific resistance value (Ω-cm)

Charging time: The time from injecting the liquid crystal composition into the cell and turning it on using an electrostatic gun until it returns to the state where no voltage is applied (seconds) Use the following abbreviations in the compound description

-n (number) C H (alkyl side chain is number, representative

nn 22nn ++ ll

When it is R. )

-On: — OC H

n 2n + l

-ndm:-(CH-CH = CH- (CH))

n 2n + l 2 m-1

ndm-: CH-CH = CH- (CH) -n2n + l2m-1

-Od (m) n: -0 (C H -CH = CH- (CH))

n 2n + l 2 m-2

d (m) nO-: C H -CH = CH- (CH) O- n 2n + l 2 m-2

Note that m also represents a number like n. Linking group

-VO-: -COO- -T-: -C≡C- -2-: -CH CH-

twenty two

Substituent

-CN: -C≡N -F: -F

Ring

Ph: 1,4-phenylene group Phi: 3-fluoro-1,4-phenylene group

Ph2: 3,5-difluoro-1,4-phenylene group

Ma: pyrimidine-2,5-diyl group Cy: 1,4-cyclohexylene group

(Example Comparative Example 1)

The following nematic liquid crystal composition (HI) was prepared, and its physical properties were measured. The results are shown in Table 1.

[Table 1] Composition and physical properties of Ι-ί 1

Liquid crystal composition H 1 (%)

2- Ph-V0 Phl-CN 4

3 Ph VO- Phl-CN 3

4- Ph-VO-Phl-C 6

5- Cy-V0-Phl-F 6

Ocll-Cy-Cy-5 14.5

3- Cy- V0- Ph- 02 丄 4

3-Cy-Ph-02 1.5

Composition 3-Cy- 2- Cy-VO- Phi- F 4

3-Cy-Cy-VO-Phl-F 8

Odl-Cy-Cy-Ph-1 10

0d: 5- Cy-Cy- Ph 1

14

3-Cy- Cy-VO Ph- Cy 2

Four

3-Cy- Cy- VO- Ph Cy-3

Four

3-Cy- Cy- VO- Ph-Cy-4

Four

3 "Cy ~ Cy-VO-Ph-Cy-5

Three

TN.〗 (° C) 1 1 9 8

ΔF 7.0

A n 0. 0 9 8

p (Ωcm) 7.8 X 1 O ^{1 1}

[0047] The obtained liquid crystal composition HI is characterized in that abnormal alignment is maintained for a long time of 300 seconds unless effective measures are taken for relatively long charging time of liquid crystal molecules with respect to the application of a temporary voltage. have.

[0048] As Examples 1-2 to 1-4, a liquid crystal composition (LC1, LC-1) obtained by adding Emalbon S-83 or T-20 (manufactured by Toho Chemical Industry Co., Ltd.) to the HI as Examples 1-2 to 1-4. LC2 and LC3) were prepared. For comparison, nematics were used as Comparative Examples 1-2 and 1-2. Liquid crystal compositions (R1 and R2) were prepared by adding tetraethylene glycol dimethyl ether (TEG), a nonionic surfactant represented by the following general formula, to liquid crystal composition HI.

[0049]

H ₃ CO CH ₂ OCH ₂ 0) ₄ CH ₃ (TEG)

[0050] Their specific resistance values and charging characteristics when injected into a 6.0 m TN cell were measured, and the results are shown in Table 2.

[Table 2]

Antistatic I-effect

The nematic liquid crystal composition LC1 has a shorter charging time without lowering the specific resistance and the liquid crystal phase upper limit temperature as compared with HI to which no semipolar organic boron compound is added.

LC2 and LC3 further shorten the charging time without lowering the specific resistance and the maximum temperature of the liquid crystal phase. On the other hand, in the case of R1 prepared by adding TEG, even if 0.1% of 10 times the amount of LC1 is added, the specific resistance is lowered and the effect is high despite the lower liquid crystal phase maximum temperature. No. In addition, in the case of R2, which was added with 0.2% of 20%, the effect of shortening the charging time was observed, but the effect was not sufficient, but the maximum temperature of the liquid crystal phase was lowered.

[0053] When TEG is used in this way, the effect cannot be obtained unless the added amount is further increased, and a significant decrease in the resistance value and the liquid crystal phase upper limit temperature is expected as compared with the compositions of LC1 to LC3. Thus, it could not be used as a practical liquid crystal composition.

Example 2

[0054] The following nematic liquid crystal composition (H2) was prepared, and its physical property values were measured. The results are shown in Table 3.

[Table 3]

Composition and physical properties of H2

[0056] The obtained liquid crystal composition H2 has a relaxation time of liquid crystal molecules with respect to the application of a temporary voltage. The charging time in the case of no countermeasures, shorter than H2, is about 30 seconds. A liquid crystal composition (LC4 and LC5) obtained by adding high boron EB-6 (manufactured by Boron International) as a charge transfer complex containing a semipolar organic boron compound to this H2 was prepared in Examples 2-1 and 2 Prepared as -2. For comparison, as Comparative Examples 2-1 and 2-2, a liquid crystal composition (R3) was prepared by adding the same nonionic surfactant, tetraethylene glycol dimethyl ether as in Example 1, to nematic liquid crystal composition H2. And R4) were prepared. Their specific resistance values and charging characteristics when injected into a TN cell of 6. O / zm were measured, and the results are shown in Table 4.

[0057] [Table 4]

Antistatic effect

When the liquid crystal composition H2 having a relatively short charging time is used, the charging time can be reduced to 0.1 second or less in the LC4 containing 0.01% of EB-6, and the liquid crystal phase temperature can be reduced. No decrease in range was seen. When 0.1% of EB-6 is added, the upper limit temperature of the liquid crystal phase decreases, but for EB-6, the addition of 0.01% as described above requires a sufficiently short charging time for practical use. Can be. On the other hand, in R3 added with 0.1% TEG, the decrease in specific resistance can be minimized, but there is no effect of shortening the charging time.In R4 added with 0.2%, the specific resistance does not decrease. However, the charging time has not been sufficiently shortened, On the other hand, a significant decrease in the maximum temperature of the liquid crystal phase was expected, so that it could not be used as a practical liquid crystal composition.

Example 3

A nematic liquid crystal composition (H3) shown below was prepared, and a liquid crystal composition (LC6) having 99.99% of H3 and emalbon S-83 as a semipolar organic boron compound having 0.01% power was prepared. It was adjusted. Further, a liquid crystal composition (LC7) comprising 99.997% of H3 and 0.003% of T20 was prepared.

[Table 5]

Composition of L C 14

[0061] Liquid crystal compositions LC6 and LC7 were also found to have an effect of shortening the charging time.

Industrial applicability

[0062] The liquid crystal molecules have a moderately large specific resistance value without using a material that significantly lowers the specific resistance, and the liquid crystal molecules cannot respond to a temporary application of voltage due to charging of the liquid crystal display element by static electricity or the like. Provided is a liquid crystal composition capable of rapidly relaxing abnormal alignment. The nematic liquid crystal composition of the present invention has a moderately large specific resistance value, and has a feature of rapidly relaxing abnormal alignment of liquid crystal molecules with respect to temporary application of voltage due to charging by static electricity or the like. The discharge time of the charge caused by the charging in the manufacturing process is shortened, and the liquid crystal display element can be efficiently manufactured.

Claims

The scope of the claims

A semipolar organoboron compound or one or more charge-transfer complexes composed of the semipolar organoboron compound, the number of boron atoms in one molecule of the semipolar organoboron compound is 5 or less, and the specific resistance value is 1. 0 10 ^{1 ()} 0 ′ 11 or more and 1.0Χ10 ¹³ Ω · «η or less.

[2] At least one of the semipolar organoboron compounds has the general formula (I)

[Formula 12]

2. The nematic liquid crystal composition according to claim 1, which is a compound having a skeleton represented by: 3. The nematic liquid crystal according to claim 2, wherein the charge transfer complex composed of a semipolar organic boron compound contains a compound having a skeleton represented by the general formula (I) and a charge transfer complex composed of an amine compound. Composition. 3. The nematic liquid crystal composition according to claim 2, wherein the semipolar organoboron compound contains a compound represented by the general formula (1-1) or (1-2).

[Formula 13]

(Wherein R ¹ and R ² are each independently a hydrogen atom, a hydroxyl group, an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, an alkenyl group having 2 to 12 carbon atoms, Alkenyl group having 1 to 12 carbon atoms, alkyl group having 1 to 12 carbon atoms substituted by halogen, alkoxy group having 1 to 12 carbon atoms substituted by halogen, Represents an alkenyl group having 2 to 12 carbon atoms or a alkenyl group having 2 to 12 carbon atoms substituted by halogen, wherein A ¹ and A ² are each independently a single bond, an alkylene group having 1 to 10 carbon atoms. , An aryl group having 6 to 18 carbon atoms, — (one (CH) O—) — (n is 1 to

2 n m

2

And — and p and q each independently represent an integer of 1 to 10. When there are a plurality of forces A ¹ and A ² , they may be the same or different. )

[5] As a charge transfer complex composed of a semipolar organic boron compound, a charge transfer complex composed of a compound represented by the general formula (1-1) or the general formula (1-2) and an amine compound is contained. 5. The nematic liquid crystal composition according to claim 4, wherein

6. The nematic liquid crystal composition according to claim 5, wherein the amine compound is a tertiary amine.

[7] containing one or more compounds represented by the following general formula (II),

2. The nematic liquid crystal composition according to claim 1, comprising one or more compounds represented by the following general formula (III).

[Formula 14]

(Wherein, R ⁴ is a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, an alkyl group having 1 to 12 carbon atoms substituted by at least one halogen, an alkyl group having 2 to 12 carbon atoms, or at least Represents a C 2 to C 12 alkyl group substituted by one halogen, and one or more CH groups present in these groups each independently have an O atom

2

B ¹ and B ² may be replaced by oxygen, sulfur, CO—, —COO—, —OCO— or OCO—O—, which are not directly bonded to each other. -1,4-cyclohexylene group (one CH group or non-adjacent 2

2

Each CH group may be replaced by an oxygen atom or a sulfur atom. ), 1,4-phenylene group (

2

One or more CH groups present in this group may be replaced by nitrogen atoms. ), 1,4-cyclohexelene, 1,4-bicyclo [2.2.2] otatylene, piperidine 1,4-diyl, naphthalene 2,6-diyl, decahydronaphthalene 2,6-diyl Represents a group or 1,2,3,4-tetrahydronaphthalene 2,6-diyl group, and the hydrogen atom present in these groups may be substituted with CN or halogen.

s and t are each independently, a force representing 0 1 or 2 The sum of s and t is 3 or less, and Z ¹ and Z ² are independently CH CH CH = CH — CH (CH) CH CH

2 2 3 2 2

CH (CH) CH (CH) CH (CH) CF CF CF = CF CH O O

3 3 3 2 2 2

CH OCH (CH) CH (CH) 0 CH) (CH) O 0 (CH)

2 3 3 2 4 2 3 2 3 C≡C CF O OCF COO OCO COS SCO or

twenty two

Represents a join,

L ¹ and L ³ each independently represent a HF or C1, L ² ^{is, F Cl CN - CF B 2} Z 1 and Z ² are double

When there are numbers, they may be the same or different. )

[Formula 15]

(Wherein, R ⁵ and R ⁶ each independently represent the same meaning as R ⁴ in formula (II), and C \ C ² and C ³ each independently represent a trans 1,4-cyclohexylene group (One CH group or two non-adjacent CH groups in this group are oxygen or sulfur atoms.

twenty two

May be replaced by ), 1,4-phenylene group (one or more CH groups present in this group may be substituted by a nitrogen atom), 1,4-cyclohexene-ylene group, 1,4 -Bicyclo [2.2.2] otathylene group, piperidine 1,4-diyl group, naphthalene 2,6-diyl group, decahydronaphthalene 2,6-diyl group or 1,2,3,4-tetrahydronaphthalene 2, Represents a 6-diyl group, and the hydrogen atoms present in these groups are methyl, CN or halogen Can be replaced with

u, V and w each independently represent 0 or 1,

Z ³ , Z ⁴ and Z ⁵ are each independently CH CH CH = CH-,-CH (CH) CH

2 2 3 2 CH CH (CH) CH (CH) CH (CH) CF CF CF = CF CH

2 3 3 3 2 2

O -OCH OCH (CH) CH (CH) 0 (CH) (CH) O

2 2 3 3 2 4 2 3

O (CH) C≡C -CF O -OCF COO OCO COS SC

2 3 2 2

O CH = N— N = CH— or a single bond. ) General formula (11-1), General formula (11-2), General formula (11-3), General formula (11-4), General formula (11-5), General formula (Π-6), General formula The compound represented by the formula (Π-7) and the compound represented by the formula (群 -8): group strength The compound represented by the formula (II) contains at least one selected compound as the compound represented by the formula (II). The nematic liquid crystal composition described.

[Formula 16]

(In the formula, R ⁴ represents an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, a alkenyl group having 2 to 12 carbon atoms, or an alkenyl group having 2 to 12 carbon atoms, X ¹ and X ² each independently represent a hydrogen atom or a fluorine atom; L ¹ and L ³ each independently Represents H or F, L ² represents F, —CN CF OCH F, —OCHF OCF or

3 2 3 represents CH CF. )

2 3 The following general formula (ΙΠ-1), general formula (111-2), general formula (111-3), general formula (111-4), general formula (ΠΙ-5), general formula (111-6) A compound represented by the general formula (III-7) and the compound represented by the general formula (III-8); and a compound comprising at least one selected compound as the compound represented by the general formula (III). 8. The nematic liquid crystal composition according to claim 7.

[Formula 17]

(Wherein, R ⁵ and R ° each independently represent an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, a alkenyl group having 2 to 12 carbon atoms, and an alkenyl group having 2 to 12 carbon atoms. -A oxy group, an alkyl group having 1 to 12 carbon atoms substituted by halogen, an alkoxy group having 1 to 12 carbon atoms substituted by halogen, an alkyl group having 2 to 12 carbon atoms substituted by halogen or Aruke from 2 carbon atoms which is substituted by halogen 12 - Ruokishi group represents, Upsilon \ Upsilon ^2, Upsilon ³ and Upsilon ⁴ are each independently - H, represents -F or a methyl group, Zeta ⁷ is CH CH CH = CH — COO— OCO— or a single bond, Z ⁸ is C

twenty two

≡C COO— OCO— or CH = N— N = CH— ) Including semipolar organoboron compounds and charge transfer complexes containing semipolar organoboron compounds 2. The nematic liquid crystal composition according to claim 1, wherein the proportion is in the range of 0.0001 to 1% by mass.

[11] The liquid crystal composition according to claim 1, wherein Δε indicates the dielectric anisotropy of the liquid crystal composition and is in the range of not less than 20 and Δη indicating the refractive index anisotropy is in the range of not less than 0.06 and not more than 0.16. 2. The nematic liquid crystal composition according to item 1.

[12] A liquid crystal display device comprising the liquid crystal composition according to claim 11 as a constituent member,