CN111187629A

CN111187629A - Liquid crystal composition and liquid crystal display element

Info

Publication number: CN111187629A
Application number: CN201910911103.6A
Authority: CN
Inventors: 须藤豪; 杨焯
Original assignee: DIC Corp
Current assignee: Shijiazhuang Chengzhi Yonghua Display Material Co Ltd
Priority date: 2018-11-14
Filing date: 2019-09-25
Publication date: 2020-05-22
Also published as: JP7163733B2; JP2020079371A; KR20200056299A

Abstract

The present invention addresses the problem of providing a polymerizable compound-containing liquid crystal composition that can achieve a high polymerization rate, a large tilt angle formation, a high tilt angle stability, and a high Voltage Holding Ratio (VHR) at the same time, and a PSA-type or PSVA-type liquid crystal display element using the same. The liquid crystal composition of the present invention solves the above problems by providing a liquid crystal composition containing a plurality of specific polymerizable compounds represented by general formulae (RM-13) and (RM-22) in combination, and a liquid crystal display element using the liquid crystal composition. (in the formula, P³、P⁴、P⁵And P⁶Represents a polymerizable group, S³Represents a single bond or an alkylene group having 1 to 5 carbon atoms, Y¹To Y¹²Represents a fluorine atom or a hydrogen atom, and at least one represents a fluorine atom, A¹To A⁸Represents a hydrogen atom or an alkoxy group having 1 to 5 carbon atoms. )

Description

Liquid crystal composition and liquid crystal display element

Technical Field

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

Background

As liquid crystal display elements using liquid crystal compositions having a negative dielectric anisotropy Δ ∈ that exhibit a negative value, PSA, PSVA mode liquid crystal TV, liquid crystal monitors, and the like have become widespread, and as liquid crystal compositions suitable for these, patent document 1, patent document 2, patent document 3, patent document 4, patent document 5, and the like disclose various polymerizable compounds and liquid crystal compositions containing the same. For example, patent document 5 discloses a combination of a polymerizable compound M1B1 and a polymerizable compound M2A1,

[ solution 1]

With this combination, preferable results were obtained with respect to both the tilt angle, the concentration of the unreacted polymerizable compound (typically, Reactive Mesogen (RM)), and the Voltage Holding Ratio (VHR). Further, patent documents 6, 7, and 8 disclose a polymerizable compound having a biphenyl skeleton and a polymerizable compound having a terphenyl skeleton.

However, the characteristics of liquid crystal compositions containing polymerizable compounds that have been conventionally used are insufficient for high-definition liquid crystal TVs such as 4K and 8K. In particular, in the 4K and 8K liquid crystal display elements, which require high-definition pixels, considerable UV light is filtered out due to the increase of wiring and light shielding regions. Therefore, in the UV irradiation step for producing PSA-type or PSVA-type liquid crystal display devices, the polymerizable compound is not sufficiently polymerized, and a large amount of the polymerizable compound remains. This resulted in insufficient formation of the tilt angle, residual image due to deterioration of response speed and deterioration of alignment properties, and also in that the residual polymerizable compound was slowly polymerized during driving, and the tilt angle was changed, and thus, display defects such as burn-In (IS) were observed. Further, it was confirmed that there are cases where the tilt angle is easily changed and cases where the tilt angle is not easily changed as a characteristic of the polymerizable compound.

As described above, PSA or PSVA liquid crystal display devices such as high-definition 4K and 8K liquid crystal televisions and liquid crystal monitors are required to have extremely high characteristics clearly different from conventional ones, and liquid crystal compositions that can be stably produced using UV light weaker or less than conventional ones are required.

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open publication No. 2016 and No. 216747

Patent document 2: japanese patent laid-open publication No. 2017-14486

Patent document 3: japanese patent No. 6008065

Patent document 4: japanese patent No. 6233550

Patent document 5: japanese Kokai publication Hei-2013-538250

Patent document 6: chinese patent application publication No. 104342167 specification

Patent document 7: chinese patent application publication No. 104342170 specification

Patent document 8: international publication No. 2018/123417

Disclosure of Invention

Problems to be solved by the invention

The present invention addresses the problem of providing a polymerizable compound-containing liquid crystal composition that can simultaneously achieve formation of a large tilt angle, a high polymerization rate, a high VHR, and high tilt stability, and a PSA-type or PSVA-type liquid crystal display element using the same, in which IS sufficiently suppressed or does not occur, or a liquid crystal display element having no alignment film on at least one substrate.

Means for solving the problems

As a result of intensive studies, the present inventors have found that the above problems can be solved by a liquid crystal composition containing 2 or more polymerizable compounds having a specific chemical structure, and have completed the present invention.

That is, an object of the present invention is to provide a liquid crystal composition containing a polymerizable compound represented by the general formula (RM-13) as a first component,

[ solution 2]

(in the formula, P³And P⁴Each independently represents any one of the polymerizable groups represented by the formulae (PG-1) to (PG-5),

[ solution 3]

S³Represents a single bond or an alkylene group having 1 to 5 carbon atoms, Y¹To Y¹²Each independently represents a fluorine atom or a hydrogen atom, and at least one represents a fluorine atom. )

And a polymerizable compound represented by the general formula (RM-22) as a second component.

[ solution 4]

(in the formula, P⁵And P⁶Each independently represents any one of the polymerizable groups represented by the formulae (PG-1) to (PG-5),

[ solution 5]

A¹To A⁸Each independently represents a hydrogen atom or an alkoxy group having 1 to 5 carbon atoms. )

Further, another object of the present invention is to provide a liquid crystal display element using the liquid crystal composition.

ADVANTAGEOUS EFFECTS OF INVENTION

The liquid crystal composition of the present invention can provide a polymerizable compound-containing liquid crystal composition which can simultaneously realize formation of a large tilt angle, a high polymerization rate, a high VHR, and high tilt stability, and a PSA-type or PSVA-type liquid crystal display element using the same, in which IS sufficiently suppressed or does not occur, or a liquid crystal display element having no alignment film on at least one substrate.

Detailed Description

The liquid crystal composition of the present invention contains a polymerizable compound represented by the general formula (RM-13) as a first component and a polymerizable group represented by the general formula (RM-22) as a second component.

[ solution 6]

[ solution 7]

[ solution 8]

[ solution 9]

In more detail, P³And P⁴Each independently is preferably formula (PG-1) or formula (PG-2), and particularly preferably formula (PG-1).

S³Represents a single bond or an alkylene group having 1 to 5 carbon atoms, preferably an alkylene group having 1 to 3 carbon atoms. Y is¹～Y¹²Each independently represents a hydrogen atom or a fluorine atom, and at least one represents a fluorine atom. Y is¹～Y¹²The total number of fluorine atoms in (2) is not particularly limited, but is preferably 1 or 2, and more preferably 1. Preferably, Y is³～Y⁶At least one of them is preferably a fluorine atom, Y³Or Y⁴At least one of them is preferably a fluorine atom.

P⁵And P⁶Each independently is preferably formula (PG-1) or formula (PG-2), and particularly preferably formula (PG-1). A. the¹To A⁸Each independently represents a hydrogen atom or an alkoxy group having 1 to 5 carbon atoms, preferably A¹To A⁸Wherein 1 or 2 of the above groups are C1-3 alkoxy groups (more preferably C1 alkoxy groups), and the rest are all hydrogen atoms, more preferably A¹To A⁸Any of them is an alkoxy group having 1 carbon atom, and the rest are all hydrogen atoms, more preferably A¹Or A²Either one of them is C1 alkoxy, A¹Or A²The other of (1) and A³To A⁸Is a hydrogen atom, particularly preferably A²Is alkoxy of 1 carbon atom, A³To A⁸And A¹Is a hydrogen atom.

The polymerizable compound represented by the general formula (RM-13) as the first component is preferably a polymerizable compound represented by the formulae (RM-131) to (RM-145), and more preferably a polymerizable compound represented by the formulae (RM-131) to (RM-136).

[ solution 10]

[ solution 11]

[ solution 12]

The polymerizable compound represented by the general formula (RM-22) which is the second component is preferably a polymerizable compound represented by the general formula (RM-22O1) to (RM-22O8), and more preferably a polymerizable compound represented by the general formula (RM-22O1) to (RM-22O 2).

[ solution 13]

The lower limit of the content of the first component in the liquid crystal composition of the present invention is preferably 0.001 mass%, preferably 0.005 mass%, preferably 0.01 mass%, preferably 0.02 mass%, preferably 0.03 mass%, preferably 0.1 mass%, preferably 0.2 mass%, preferably 0.3 mass%, preferably 0.4 mass%; the upper limit is preferably 3% by mass, more preferably 2% by mass, more preferably 1% by mass, more preferably 0.5% by mass, more preferably 0.4% by mass, more preferably 0.3% by mass, more preferably 0.2% by mass, and even more preferably 0.1% by mass. Hereinafter, the mass% may be referred to as%.

The lower limit of the content of the second component in the liquid crystal composition of the present invention is preferably 0.001 mass%, preferably 0.005 mass%, preferably 0.01 mass%, preferably 0.02 mass%, preferably 0.03 mass%, preferably 0.1 mass%, preferably 0.2 mass%, preferably 0.3 mass%, preferably 0.4 mass%; the upper limit is preferably 3% by mass, more preferably 2% by mass, more preferably 1% by mass, more preferably 0.5% by mass, more preferably 0.4% by mass, and even more preferably 0.3% by mass.

The lower limit of the total content of the first component and the second component in the liquid crystal composition of the present invention is preferably 0.01 mass%, preferably 0.02 mass%, preferably 0.03 mass%, preferably 0.1 mass%, preferably 0.2 mass%, preferably 0.3 mass%, preferably 0.4 mass%; the upper limit is preferably 6% by mass, preferably 3% by mass, more preferably 2% by mass, more preferably 1% by mass, more preferably 0.6% by mass, more preferably 0.5% by mass, and even more preferably 0.4% by mass.

The content ratio of the first component to the second component in the composition of the present invention is preferably, in terms of mass ratio, the first component: the second component is 1: 1-10, preferably 1: 3-8, more preferably 1: 5 to 7.

The liquid crystal composition of the present invention preferably contains 1 or 2 or more compounds selected from the group of compounds represented by the general formulae (N-01), (N-02), (N-03), (N-04) and (N-05). These compounds correspond to compounds having negative dielectric anisotropy. The "compound having negative dielectric anisotropy" refers to a compound in which Δ ∈ has a negative sign and the absolute value thereof shows a value greater than 2. Wherein Δ ∈ of the compound is a value obtained by extrapolating a measured value of dielectric anisotropy of a composition obtained by adding the compound to a composition having a substantially neutral dielectric property at 25 ℃.

[ solution 14]

In the formula, R²¹And R²²Each independently represents an alkyl group having 1 to 8 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, an alkenyl group having 2 to 8 carbon atoms, an alkenyloxy group having 2 to 8 carbon atoms, Z¹Each independently represents a single bond, -CH₂CH₂-、-OCH₂-or-CH₂O-, and m each independently represents 1 or 2.

R²¹The alkyl group is preferably an alkyl group having 1 to 8 carbon atoms, more preferably an alkyl group having 1 to 5 carbon atoms, and still more preferably an alkyl group having 2 to 4 carbon atoms. Wherein Z is¹In the case of a structure other than a single bond, R²¹Preferably an alkyl group having 1 to 3 carbon atoms.

R²²Preferably an alkyl group having 1 to 8 carbon atoms or an alkoxy group having 1 to 8 carbon atoms, more preferably an alkyl group having 1 to 5 carbon atoms or an alkoxy group having 1 to 4 carbon atoms, and still more preferably an alkoxy group having 1 to 4 carbon atoms.

R²¹And R²²In the case of alkenyl groups, preferred are those of the formulae (R1) to (R5),

[ solution 15]

(the black dot in each formula represents a carbon atom in the ring structure.) is more preferably formula (R1) or formula (R2).

Z¹Further preferred are, independently of one another, a single bond, -CH₂CH₂-or-CH₂O-。

When m is 1, Z¹Preferably a single bond.

When m is 2, Z¹Is preferably-CH₂CH₂-or-CH₂O-。

In the liquid crystal composition of the present invention, the compound represented by the general formula (N-01) preferably contains 1 or 2 or more compounds selected from the group consisting of compounds represented by the general formula (N-01-1), the general formula (N-01-2), the general formula (N-01-3) and the general formula (N-01-4).

[ solution 16]

(in the formula, R²¹Each independently represents an alkyl group having 1 to 5 carbon atoms, R²³Each independently represents an alkoxy group having 1 to 4 carbon atoms. )

The liquid crystal composition of the present invention preferably contains a polymerizable compound as a first component, a polymerizable compound as a second component, and one or more compounds selected from the group of compounds represented by general formulae (N-01-1) to (N-01-4).

The liquid crystal composition of the present invention preferably contains a polymerizable compound as a first component, a polymerizable compound as a second component, a compound represented by the general formula (N-01-1) and a compound represented by the general formula (N-01-4).

The liquid crystal composition of the present invention preferably contains a polymerizable compound as a first component, a polymerizable compound as a second component, a compound represented by the general formula (N-01-3) and a compound represented by the general formula (N-01-4).

In the liquid crystal composition of the present invention, the compound represented by the general formula (N-02) preferably contains 1 or 2 or more compounds selected from the group consisting of compounds represented by the general formula (N-02-1), the general formula (N-02-2) and the general formula (N-02-3).

[ solution 17]

The liquid crystal composition of the present invention particularly preferably contains a polymerizable compound as a first component, a polymerizable compound as a second component, and a compound represented by the general formula (N-02-1).

The liquid crystal composition of the present invention preferably contains a polymerizable compound as a first component, a polymerizable compound as a second component, a compound represented by the general formula (N-02-1) and a compound represented by the general formula (N-02-3).

The liquid crystal composition of the present invention preferably contains a polymerizable compound as a first component, a polymerizable compound as a second component, a compound represented by the general formula (N-02-1) and a compound represented by the general formula (N-01-4).

In the liquid crystal composition of the present invention, it is preferable that the compound represented by the general formula (N-03) contains 1 or 2 or more compounds represented by the general formula (N-03-1).

[ solution 18]

(in the formula, R²¹Represents an alkyl group having 1 to 5 carbon atoms, R²³Represents an alkoxy group having 1 to 4 carbon atoms. )

The liquid crystal composition of the present invention preferably contains a polymerizable compound as a first component, a polymerizable compound as a second component, and a compound represented by the general formula (N-03-1).

The liquid crystal composition of the present invention preferably contains a polymerizable compound as a first component, a polymerizable compound as a second component, a compound represented by the general formula (N-03-1) and a compound represented by the general formula (N-01-4).

The liquid crystal composition of the present invention preferably contains a polymerizable compound as a first component, a polymerizable compound as a second component, a compound represented by the general formula (N-03-1) and a compound represented by the general formula (N-02-1).

The liquid crystal composition of the present invention preferably contains a polymerizable compound as a first component, a polymerizable compound as a second component, and a compound represented by the general formula (N-03-1), a compound represented by the general formula (N-01-4), and a compound represented by the general formula (N-02-1).

In the liquid crystal composition of the present invention, it is preferable that the compound represented by the general formula (N-04) contains 1 or 2 or more compounds represented by the general formula (N-04-1).

[ solution 19]

The liquid crystal composition of the present invention preferably contains a polymerizable compound as a first component, a polymerizable compound as a second component, and a compound represented by the general formula (N-04-1) at the same time.

The liquid crystal composition of the present invention particularly preferably contains a polymerizable compound as the first component, a polymerizable compound as the second component, a compound represented by the general formula (N-04-1) and a compound represented by the general formula (N-01-4) at the same time.

The liquid crystal composition of the present invention particularly preferably contains a polymerizable compound as the first component, a polymerizable compound as the second component, and a compound represented by the general formula (N-04-1), a compound represented by the general formula (N-01-4) and a compound represented by the general formula (N-02-1) at the same time.

The liquid crystal composition of the present invention particularly preferably contains a polymerizable compound as the first component, a polymerizable compound as the second component, and a compound represented by the general formula (N-04-1), a compound represented by the general formula (N-01-4) and a compound represented by the general formula (N-03-1) at the same time.

The liquid crystal composition of the present invention particularly preferably contains a polymerizable compound as the first component, a polymerizable compound as the second component, and a compound represented by the general formula (N-04-1), a compound represented by the general formula (N-02-1), and a compound represented by the general formula (N-03-1) at the same time.

The liquid crystal composition of the present invention particularly preferably contains a polymerizable compound as the first component, a polymerizable compound as the second component, and a compound represented by the general formula (N-04-1), a compound represented by the general formula (N-01-4), a compound represented by the general formula (N-02-1), and a compound represented by the general formula (N-03-1) at the same time.

The liquid crystal composition of the present invention may contain, as the compound represented by the general formula (N-05), a compound selected from the group consisting of compounds represented by the formulae (N-05-1) to (N-05-3).

[ solution 20]

The lower limit of the preferable content of the compound represented by the general formula (N-01) is 0%, 1%, 5%, 10%, 20%, 30%, 40%, 50%, 55%, 60%, 65%, 70%, 75%, 80% relative to the total amount of the liquid crystal composition of the present invention; the upper limit of the content is preferably 95%, 85%, 75%, 65%, 55%, 45%, 35%, 25%, 20%, 15%, 10%.

The lower limit of the preferable content of the compound represented by the general formula (N-02) is 0%, 1%, 5%, 10%, 20%, 30%, 40%, 50%, 55%, 60%, 65%, 70%, 75%, 80% relative to the total amount of the liquid crystal composition of the present invention; the upper limit of the content is preferably 95%, 85%, 75%, 65%, 55%, 45%, 35%, 25%, 20%, 15%, 10%.

The lower limit of the preferable content of the compound represented by the general formula (N-03) is 0%, 1%, 5%, 10%, 20%, 30%, 40%, 50%, 55%, 60%, 65%, 70%, 75%, 80% relative to the total amount of the liquid crystal composition of the present invention; the upper limit of the content is preferably 95%, 85%, 75%, 65%, 55%, 45%, 35%, 25%, 20%, 15%, 10%.

The lower limit of the preferable content of the compound represented by the general formula (N-04) relative to the total amount of the liquid crystal composition of the present invention is 0%, 1%, 5%, 10%, 20%, 30%, 40%, 50%, 55%, 60%, 65%, 70%, 75%, 80%; the upper limit of the content is preferably 95%, 85%, 75%, 65%, 55%, 45%, 35%, 25%, 20%, 15%, 10%.

The lower limit of the preferable content of the compound represented by the formula (N-05) is 0%, 2%, 5%, 8%, 10%, 13%, 15%, 17%, 20% with respect to the total amount of the liquid crystal composition of the present invention; the upper limit of the content is preferably 30%, 28%, 25%, 23%, 20%, 18%, 15%, 13%.

The liquid crystal composition of the present invention contains 1 or 2 or more compounds selected from the group of compounds represented by general formulae (NU-01) to (NU-08).

[ solution 21]

(in the formula, R^NU11、R^NU12、R^NU21、R^NU22、R^NU31、R^NU32、R^NU41、R^NU42、R^NU51、R^NU52、R^NU61、R^NU62、R^NU71、R^NU72、R^NU81And R^NU82Each independently represents an alkyl group having 1 to 8 carbon atoms, a carbon atomAn alkoxy group of 1 to 8, an alkenyl group of 2 to 8 carbon atoms, or an alkenyloxy group of 2 to 8 carbon atoms. )

More specifically, R^NU11、R^NU12、R^NU21、R^NU22、R^NU31、R^NU32、R^NU41、R^NU42、R^NU51、R^NU52、R^NU61、R^NU62、R^NU71、R^NU72、R^NU81And R^NU82An alkyl group having 1 to 5 carbon atoms or an alkoxy group having 1 to 5 carbon atoms is preferable, and an alkyl group having 1 to 5 carbon atoms is more preferable. In the case where importance is attached to the response speed, at least 1R is preferable^NU11、R^NU21、R^NU41And R^NU51The alkenyl group having 2 to 3 carbon atoms is preferably an alkenyl group represented by the formula (R2).

The amount of the compound having an alkenyl group is preferably 30% or less, preferably 25% or less, preferably 20% or less, preferably 15% or less, preferably 10% or less, preferably 5% or less, based on the total amount of the liquid crystal composition of the present invention. When high VHR is regarded as important, the amount of the compound having an alkenyl group is preferably 10% or less, preferably 5% or less, preferably 1% or less, and preferably not contained.

More specifically, R^NU11、R^NU21、R^NU31、R^NU41、R^NU51、R^NU61、R^NU71、R^NU81Particularly preferably an alkyl group of 1 to 5 carbon atoms, R^NU12、R^NU22、R^NU32、R^NU42、R^NU52、R^NU62、R^NU72And R^NU82Particularly preferred is an alkyl group having 1 to 5 carbon atoms or an alkoxy group having 1 to 5 carbon atoms.

The liquid crystal composition of the present invention preferably contains a compound represented by the general formula (NU-01) and a compound represented by the general formula (NU-02).

The liquid crystal composition of the present invention preferably contains a compound represented by the general formula (NU-01) and a compound represented by the general formula (NU-03).

The liquid crystal composition of the present invention preferably contains a compound represented by the general formula (NU-03) and a compound represented by the general formula (NU-04).

The liquid crystal composition of the present invention preferably contains a compound represented by the general formula (NU-03) and a compound represented by the general formula (NU-05).

The liquid crystal composition of the present invention preferably contains a compound represented by the general formula (NU-01) and a compound represented by the general formula (NU-06).

The liquid crystal composition of the present invention preferably contains a compound represented by the general formula (NU-01) and a compound represented by the general formula (NU-07).

The liquid crystal composition of the present invention preferably contains a compound represented by the general formula (NU-01) and a compound represented by the general formula (NU-08).

The liquid crystal composition of the present invention preferably further contains a compound represented by the general formula (NU-01), a compound represented by the general formula (NU-02), and a compound represented by the general formula (NU-04).

The liquid crystal composition of the present invention preferably further contains a compound represented by the general formula (NU-01), a compound represented by the general formula (NU-03), and a compound represented by the general formula (NU-05).

The liquid crystal composition of the present invention preferably further contains a compound represented by the general formula (NU-01), a compound represented by the general formula (NU-02), a compound represented by the general formula (NU-03), and a compound represented by the general formula (NU-05).

The content of the compound represented by the general formula (NU-01) is preferably 1 to 60% by mass, more preferably 10 to 50% by mass, and still more preferably 20 to 40% by mass.

The content of the compound represented by the general formula (NU-02) is preferably 1 to 40% by mass, more preferably 5 to 25% by mass, and still more preferably 5 to 20% by mass.

The content of the compound represented by the general formula (NU-03) is preferably 1 to 20% by mass, more preferably 0 to 15% by mass, and still more preferably 0 to 10% by mass.

The content of the compound represented by the general formula (NU-04) is preferably 1 to 30% by mass, more preferably 3 to 20% by mass, and still more preferably 3 to 10% by mass.

The content of the compound represented by the general formula (NU-05) is preferably 1 to 30% by mass, more preferably 1 to 20% by mass, and still more preferably 3 to 20% by mass.

The content of the compound represented by the general formula (NU-06) is preferably 1 to 30% by mass, more preferably 3 to 20% by mass, and still more preferably 3 to 10% by mass.

The content of the compound represented by the general formula (NU-07) is preferably 1 to 30% by mass, more preferably 3 to 20% by mass, and still more preferably 3 to 10% by mass.

The content of the compound represented by the general formula (NU-08) is preferably 1 to 30% by mass, more preferably 3 to 20% by mass, and still more preferably 3 to 10% by mass.

The liquid crystal composition of the present invention may contain 1 or 2 or more compounds having positive dielectric anisotropy described in paragraphs 0236 to 0509 of patent document 4 (japanese patent No. 6233550).

The composition of the present invention preferably does not contain a compound having a structure in which oxygen atoms are linked to each other, such as a peracid (-CO-OO-) structure, in the molecule.

When importance is attached to the reliability and long-term stability of the liquid crystal composition, the content of the compound having a carbonyl group is preferably 5% or less, more preferably 3% or less, still more preferably 1% or less, and most preferably substantially none, based on the total mass of the composition.

When importance is attached to the stability against UV irradiation, the content of the compound substituted with a chlorine atom is preferably 15% or less, preferably 10% or less, preferably 8% or less, more preferably 5% or less, preferably 3% or less, and further preferably substantially not contained, with respect to the total mass of the composition.

The content of the compound having all the ring structures in the molecule as 6-membered rings is preferably increased, and the content of the compound having all the ring structures in the molecule as 6-membered rings is preferably 80% or more, more preferably 90% or more, further preferably 95% or more, and most preferably the composition is composed substantially of only the compound having all the ring structures in the molecule as 6-membered rings, based on the total mass of the composition.

In order to suppress deterioration due to oxidation of the liquid crystal composition, the content of the compound having a cyclohexenylene group as a ring structure is preferably small, and the content of the compound having a cyclohexenylene group is preferably 10% or less, preferably 8% or less, more preferably 5% or less, preferably 3% or less, and further preferably substantially not contained, with respect to the total mass of the composition.

Emphasis is placed on viscosity improvement and T_NIIn the case of the improvement of (3), the content of the compound having 2-methylbenzene-1, 4-diyl group in which a hydrogen atom is substitutable with halogen is preferably reduced, and the content of the compound having the 2-methylbenzene-1, 4-diyl group in the molecule is preferably 10% or less, preferably 8% or less, more preferably 5% or less, preferably 3% or less, and further preferably substantially not contained, with respect to the total mass of the composition.

The term "substantially free" in the present application means not containing substances other than substances that are not intentionally contained.

In addition to the above compounds, the liquid crystal composition of the present invention may contain a conventional nematic liquid crystal, smectic liquid crystal, cholesteric liquid crystal, antioxidant, ultraviolet absorber, light stabilizer, infrared absorber, or the like.

The liquid crystal composition of the present invention preferably contains an antioxidant so that polymerization does not occur in a heating treatment which is one of the steps of manufacturing a liquid crystal display element.

The liquid crystal composition of the present invention preferably contains the antioxidant represented by the general formula (H-1) to the general formula (H-4) in an amount of preferably 10 mass ppm, preferably 20 mass ppm, preferably 50 mass ppm at the lower limit and 10000 mass ppm, preferably 1000 mass ppm, preferably 500 mass ppm, preferably 100 mass ppm at the upper limit.

[ solution 22]

In the general formulae (H-1) to (H-3), R^H1Each independently represents an alkyl group having 3 to 7 carbon atoms. Further specifically, R of the formula (H-1)^H1Represents an alkyl group having 7 carbon atoms. R of the formula (H-2)^H1To representAn alkyl group having 3 carbon atoms. R of the formula (H-3)^H1Represents an alkyl group having 3 carbon atoms.

In the general formula (H-4), M^H1Represents an alkylene group having 4 to 10 carbon atoms (1 or 2 or more-CH in the alkylene group)₂-may be substituted by-COO-or-OCO-in such a way that the oxygen atoms are not directly adjacent. ) Any hydrogen atom in the single bond and 1, 4-phenylene (1, 4-phenylene) group may be substituted with a fluorine atom. ) Or trans-1, 4-cyclohexylene, M^H1An alkylene group having 4 to 8 carbon atoms is preferable.

Nematic phase-isotropic liquid phase transition temperature (T) of liquid crystal composition of the present invention_NI) From 60 ℃ to 120 ℃, more preferably from 70 ℃ to 100 ℃, and particularly preferably from 70 ℃ to 85 ℃. Wherein, in the present invention, T represents 60 ℃ or higher_NIHigh.

In the case of liquid crystal television applications, T_NIPreferably 70 to 80 ℃, in the case of mobile telephone applications, T_NIPreferably 80 to 90 ℃ and T (Public Information Display) in the case of outdoor Display such as PID (Public Information Display)_NIPreferably from 90 to 110 ℃.

The liquid crystal composition of the present invention has a refractive index anisotropy (. DELTA.n) at 20 ℃ of 0.08 to 0.14, more preferably 0.09 to 0.13, and particularly preferably 0.09 to 0.12. More specifically, in the case of a thin cell gap, it is preferably 0.10 to 0.13; in the case of a cell gap corresponding to a thickness, it is preferably 0.08 to 0.10. Among them, the refractive index anisotropy (. DELTA.n) of the liquid crystal composition of the present invention at 20 ℃ is particularly preferably 0.098 to 0.118.

The liquid crystal composition of the present invention has a rotational viscosity (. gamma.) at 20 ℃₁) Is from 50 to 160 mPas, preferably from 55 to 160 mPas, preferably from 60 to 160 mPas, preferably from 80 to 150 mPas, preferably from 90 to 140 mPas, preferably from 90 to 130 mPas, preferably from 90 to 115 mPas.

The liquid crystal composition of the present invention has a dielectric anisotropy (. DELTA.. di-elect cons.) at 20 ℃ of-1.7 to-4.0, preferably-2.5 to-3.8, more preferably-2.7 to-3.7, more preferably-2.6 to-3.6.

The liquid crystal composition of the present invention preferably contains the polymerizable compound of the first component and the polymerizable compound of the second component, and further contains 1 or 2 or more compounds selected from the group consisting of the compounds represented by the general formulae (N-01), (N-02), (N-03), (N-04) and (N-05), and further contains 1 or 2 or more compounds selected from the group consisting of the compounds represented by the general formulae (NU-01) to (NU-08), and the upper limit of the total content thereof is preferably 100 mass%, 99 mass%, 98 mass%, 97 mass%, 96 mass%, 95 mass%, 94 mass%, 93 mass%, 92 mass%, 91 mass%, 90 mass%, 89 mass%, 88 mass%, 87 mass%, 86 mass%, 85 mass%, and 84 mass%, and the lower limit of the total content thereof is preferably 78 mass%, 80 mass%, 81 mass%, 83 mass%, 85 mass%, 86 mass%, 87 mass%, 88 mass%, 89 mass%, 90 mass%, 91 mass%, 92 mass%, 93 mass%, 94 mass%, 95 mass%, 96 mass%, 97 mass%, 98 mass%, 99 mass%, 100 mass%.

The liquid crystal composition of the present invention particularly preferably contains a polymerizable compound of the first component and a polymerizable compound of the second component, further contains 1 or 2 or more compounds selected from the group consisting of compounds represented by the general formulae (N-01), (N-02), (N-03) and (N-04), and further contains 1 or 2 or more compounds selected from the group consisting of compounds represented by the general formulae (NU-01) to (NU-08), and the upper limit of the total content thereof is preferably 100 mass%, 99 mass%, 98 mass%, 97 mass%, 96 mass%, 95 mass%, 94 mass%, 93 mass%, 92 mass%, 91 mass%, 90 mass%, 89 mass%, 88 mass%, 87 mass%, 86 mass%, 85 mass%, 84 mass%, and the lower limit thereof is preferably 78 mass%, (wt%), 80 mass%, 81 mass%, 83 mass%, 85 mass%, 86 mass%, 87 mass%, 88 mass%, 89 mass%, 90 mass%, 91 mass%, 92 mass%, 93 mass%, 94 mass%, 95 mass%, 96 mass%, 97 mass%, 98 mass%, 99 mass%, 100 mass%.

The liquid crystal display element using the liquid crystal composition of the present invention has a small residual amount of polymerizable compounds in the liquid crystal display element after polymerization, and display defects such as IS in high-definition PSA-type or PSVA-type liquid crystal display elements such as 4K and 8K do not occur or can be significantly suppressed. In addition, in the production of high-definition PSA-type or PSVA-type liquid crystal display elements such as 4K and 8K, the UV irradiation time is prolonged, and the production efficiency is significantly reduced. Therefore, by using the liquid crystal composition of the present invention, high-definition PSA-type or PSVA-type liquid crystal display elements such as 4K and 8K can be manufactured with a short UV irradiation time, which is very valuable in industrial use.

The liquid crystal composition of the present invention is suitable for the production of PSA-type or PSVA-type liquid crystal display devices, and also suitable for the production of NPS-type liquid crystal display devices.

The liquid crystal composition of the present invention is also suitable for a liquid crystal display element having no alignment film, that is, a mode collectively called PI-less. For example, it is preferable to use a compound having self-alignment properties described in Japanese patent application No. 2013-552125, Japanese patent application No. 2014-517515, Japanese patent No. 06081361, Japanese patent application No. 2015-546888, Japanese patent application No. 2017-12710, WO2017041893A, Japanese patent No. 06070973, WO17/047177, etc. in combination with the liquid crystal composition of the present invention.

The liquid crystal composition of the present invention is useful for liquid crystal display elements for active matrix driving, and can be used for liquid crystal display elements such as PSA, PSVA, PS-IPS, PS-FFS, and NPS.

The liquid crystal display device of the present invention preferably includes a1 st substrate and a 2 nd substrate which are arranged to face each other, a common electrode provided on the 1 st substrate or the 2 nd substrate, a pixel electrode provided on the 1 st substrate or the 2 nd substrate and having a thin film transistor, and a liquid crystal layer containing a liquid crystal composition provided between the 1 st substrate and the 2 nd substrate. If necessary, an alignment film for controlling the alignment direction of the liquid crystal molecules may be provided on the side of the substrate facing at least one of the 1 st substrate and/or the 2 nd substrate so as to be in contact with the liquid crystal layer. As the alignment film, a vertical alignment film, a horizontal alignment film, or the like can be appropriately selected in accordance with the driving mode of the liquid crystal display element, and a known alignment film such as a rubbing alignment film (for example, polyimide), a photo alignment film (for example, decomposed polyimide), or the like can be used. Further, a color filter may be provided on the 1 st substrate or the 2 nd substrate as appropriate, or a color filter may be provided on the pixel electrode or the common electrode.

The 2 substrates of the liquid crystal cell used in the liquid crystal display device of the present invention may be made of a transparent material having flexibility such as glass or plastic, and the other substrate may be made of an opaque material such as silicon. The transparent substrate having a transparent electrode layer can be obtained by, for example, sputtering Indium Tin Oxide (ITO) on a transparent substrate such as a glass plate.

The color filter can be produced by, for example, a pigment dispersion method, a printing method, an electrodeposition method, a dyeing method, or the like. A method of producing a color filter by a pigment dispersion method will be described as an example, in which a curable color composition for a color filter is applied to the transparent substrate, subjected to patterning treatment, and then cured by heating or light irradiation. This process is performed for 3 colors of red, green, and blue, respectively, whereby a pixel portion for a color filter can be manufactured. Further, a pixel electrode provided with an active element such as a TFT, a thin film diode, or a metal insulator metal resistivity element may be provided on the substrate.

Preferably, the 1 st substrate and the 2 nd substrate are opposed to each other with the common electrode and the pixel electrode layer inside.

The interval between the 1 st substrate and the 2 nd substrate may be adjusted with a spacer interposed therebetween. In this case, the thickness of the light control layer is preferably adjusted to 1 to 100 μm. More preferably 1.5 to 10 μm, and when a polarizing plate is used, the product of the refractive index anisotropy Δ n of the liquid crystal and the cell thickness d is preferably adjusted so that the contrast becomes maximum. In the case of two polarizing plates, the polarizing axes of the respective polarizing plates may be adjusted so that the viewing angle and the contrast are good. Further, a retardation film for enlarging the viewing angle can be used. Examples of the spacer include glass particles, plastic particles, alumina particles, and photoresist. Thereafter, a sealant such as an epoxy thermosetting composition is screen-printed on the substrates so as to be provided with a liquid crystal injection port as necessary, the substrates are bonded to each other, and the sealant is thermally cured by heating.

The method of holding the liquid crystal composition between 2 substrates may be a common vacuum injection method, an ODF method, or the like.

As a method of polymerizing the polymerizable compound contained in the liquid crystal composition of the present invention, polymerization at an appropriate polymerization rate is preferred in order to obtain good alignment properties of liquid crystals, and therefore, a method of polymerizing by irradiating active energy rays such as ultraviolet rays or electron rays alone or in combination or in sequence is preferred. When ultraviolet light is used, either a polarized light source or an unpolarized light source may be used. In addition, when the polymerization is performed in a state where the liquid crystal composition is sandwiched between 2 substrates, it is necessary that at least the substrate on the irradiation surface side has appropriate transparency to the active energy ray. Further, the following method may also be used: when light is irradiated, only a specific portion is polymerized using a mask, and then the orientation state of the unpolymerized portion is changed by changing the conditions such as an electric field, a magnetic field, or temperature, and further, the alignment is polymerized by irradiation with an active energy ray. In particular, when ultraviolet exposure is performed, it is preferable to perform ultraviolet exposure while applying a direct current electric field or an alternating current electric field to the liquid crystal composition. Wherein the applied alternating electric field is preferably alternating current with a frequency of 1Hz to 10kHz, more preferably with a frequency of 60Hz to 10kHz, and the voltage is selected according to the desired pretilt angle of the liquid crystal display element. That is, the pretilt angle of the liquid crystal display element can be controlled by the applied voltage. In the PSA-type or PSVA-type liquid crystal display element, the pretilt angle is preferably controlled to 80 degrees to 89.9 degrees from the viewpoints of alignment stability and contrast.

In a PSA-type or PSVA-type liquid crystal display device, if a polymerizable compound IS not polymerized but remains as it IS after the device IS manufactured, IS occurs. The amount of the residual polymerizable compound is preferably 20ppm or less, more preferably 15ppm or less, particularly preferably 10ppm or less, and particularly preferably 0 or less as the lower limit of detection.

The temperature at the time of irradiation with active energy rays such as ultraviolet rays or electron rays used for polymerizing the polymerizable compound contained in the liquid crystal composition of the present invention is not particularly limited. For example, when the liquid crystal composition of the present invention is applied to a liquid crystal display element having a substrate with an alignment film, the liquid crystal composition is preferably within a temperature range in which the liquid crystal state of the liquid crystal composition is maintained. That is, it is preferable to polymerize the monomer at 15 to 50 ℃.

As the lamp for generating ultraviolet rays, a metal halide lamp, a high-pressure mercury lamp, an ultrahigh-pressure mercury lamp, and the like can be used, and an ultrahigh-pressure UV lamp by usio corporation and a fluorescent ultraviolet lamp by TOSHIBA corporation are preferable. As the wavelength of the ultraviolet light to be irradiated, ultraviolet light whose irradiation wavelength region is not in the absorption wavelength region of the liquid crystal composition is preferable, and ultraviolet light having a shorter wavelength is preferably used by being filtered out as necessary. The intensity of the ultraviolet ray to be irradiated is preferably 0.1mW/cm²～100W/cm²More preferably 2mW/cm²～50W/cm². The amount of energy of the ultraviolet rays to be irradiated can be appropriately adjusted, and is preferably 10mJ/cm²To 500J/cm²More preferably 100mJ/cm²To 200J/cm²。

Examples

The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. In the compositions of the following examples and comparative examples, "%" means "% by mass". The following abbreviations are used in the examples for the description of the compounds.

Unless otherwise specified, each physical property value was measured by a method published by the society for electronic information technology industry, revision society for electronic information technology industry, JEITA ED-2521B 2009, revision 3 months, and described in the standard (change electronics situation technology industry size).

(side chain)

-n -C_nH_2n+1Straight chain alkyl group having carbon number n

n- C_nH_2n+1-linear alkyl group having n carbon atoms

-On -OC_nH_2n+1Straight chain alkoxy group having carbon number n

nO- C_nH_2n+1O-straight chain alkoxy group having n carbon atoms

-V -CH＝CH₂

V- CH₂＝CH-

-V1 -CH＝CH-CH₃

1V- CH₃-CH＝CH-

-F -F

-OCF3 -OCF₃

(linker)

-1O- -CH₂-O-

-O1- -O-CH₂-

-2- -CH₂-CH₂-

-COO- -COO-

-OCO- -OCO-

-single bond

(Ring structure)

[ solution 23]

The properties measured in the examples are as follows.

T_NI: nematic phase-isotropic liquid phase transition temperature (. degree.C.)

Δ n: refractive index anisotropy at 20 DEG C

Δ ε: anisotropy of dielectric constant at 20 DEG C

γ₁: rotational tack at 20 ℃ (mPa. multidot.s)

RM: illumination intensity of 313nm for 20 minutes of 3mW/cm²Residual monomer amount (ppm) in the liquid crystal display element after UV light of (1)

Tilt: illumination intensity of 313nm for 2 minutes of irradiation of 3mW/cm²Shows a change in the distance of 90 ° by a pretilt angle (°) of the liquid crystal display element after UV light.

IS: illumination intensity of 313nm for 60 minutes of preparation for 3mW/cm²The liquid crystal display element after UV light of (1) has a value obtained by multiplying the amount of change in pretilt angle after maintaining the driving state for a certain time by 100

VHR: illumination intensity of 313nm for 60 minutes of preparation for 3mW/cm²The voltage holding ratio (%), measured under the conditions of 1V, 60Hz, and 60 ℃ of the UV-irradiated liquid crystal display device of (1)

(preparation of liquid Crystal composition and evaluation results)

Liquid crystal compositions (LC-1) to (LC-4) were prepared, and their physical property values were measured. The component ratios and physical property values of these liquid crystal compositions are shown in table 1.

[ Table 1]

Examples 1(E-01) to 4(E-04) and comparative examples 1(C-01) to 2(C-02) were prepared by mixing these liquid crystal compositions with polymerizable compounds represented by the formulae (RM-131) and/or (RM-22O2), and RM, Tilt, IS and VHR were evaluated, and the results are shown in Table 2.

[ solution 24]

[ Table 2]

In examples 1(E-01) to 4(E-04), RM was 0 and was a sufficiently small value at or below the lower limit of detection. Moreover, it was confirmed that Tilt, IS and VHR thereof were sufficiently large, small and high values, respectively. From the above, it was confirmed that the embodiments solve the problems of the present invention. In contrast, it was confirmed that the IS of comparative example 1(C-01) was 135, which IS very large, and the RM of comparative example 2(C-02) was 11, which IS a large value. From the above, it was confirmed that these comparative examples could not solve the problems of the present invention.

[ solution 25]

Compositions in which the polymerizable compound represented by the formula (RM-22O2) contained in examples 1(E-01) to 4(E-04) was replaced with the polymerizable compound represented by the formula (RM-22O1) were prepared, and it was confirmed that the problems of the present invention were solved.

A composition was prepared in which the polymerizable compound represented by the formula (RM-22O2) contained in example 4(E-04) was replaced with the polymerizable compound represented by the formula (RM-22O9), and it was confirmed that the problem of the present invention was solved.

A composition was prepared in which the polymerizable compound represented by the formula (RM-131) contained in example 4(E-04) was replaced with the polymerizable compound represented by the formula (RM-133), and it was confirmed that the problem of the present invention was solved.

[ solution 26]

Further, a composition prepared by adding 50ppm of an antioxidant represented by the formula (H-2-R3) to example 1(E-01) was prepared, and it was confirmed that the problem of the present invention was solved. Further, a composition prepared by adding 50ppm of an antioxidant represented by the formula (H-3-R3) to example 1(E-01) was prepared, and it was confirmed that the problem of the present invention was solved. A composition prepared by adding 50ppm of an antioxidant represented by the formula (H-4-M8) to example 1(E-01) was prepared, and it was confirmed that the problem of the present invention was solved. A composition was prepared by replacing 3-Cy-Cy-4 contained in example 1(E-01) with 3-Cy-Cy-V1, and it was confirmed that the problem of the present invention was solved.

A composition prepared by adding 20ppm of an antioxidant represented by the formula (H-2-R3) to example 4(E-04) was prepared, and it was confirmed that the problem of the present invention was solved. Further, a composition prepared by adding 20ppm of an antioxidant represented by the formula (H-3-R3) to example 4(E-04) was prepared, and it was confirmed that the problem of the present invention was solved. A composition prepared by adding 10ppm of an antioxidant represented by the formula (H-4-M8) to example 4(E-04) was prepared, and it was confirmed that the problem of the present invention was solved.

Further, example 5(E-05) to example 10(E-10) were prepared, and RM, Tilt, IS, and VHR were evaluated, and the results are shown in Table 3.

[ solution 27]

[ Table 3]

In examples 5(E-05) to 10(E-10), RM was 0 and was a sufficiently small value at or below the lower limit of detection. Moreover, it was confirmed that Tilt, IS and VHR thereof were sufficiently large, small and high values, respectively. From the above, it was confirmed that the embodiments solve the problems of the present invention.

In the examples of the present invention, it was confirmed that the problem of the present invention was solved when a compound suitable for PI-free having an OH group as a polar group was added in an amount of about 1% and a liquid crystal display element was produced from a substrate having no alignment film.

Claims

1. A liquid crystal composition containing a polymerizable compound represented by the general formula (RM-13) as a first component and a polymerizable compound represented by the general formula (RM-22) as a second component,

[ solution 1]

In the formula, P³And P⁴Each independently represents any one of the polymerizable groups represented by the formulae (PG-1) to (PG-5),

[ solution 2]

S³Represents a single bond or an alkylene group having 1 to 5 carbon atoms, Y¹To Y¹²Each independently represents a fluorine atom or a hydrogen atom, and at least one represents a fluorine atom,

[ solution 3]

In the formula, P⁵And P⁶Each independently represents any one of the polymerizable groups represented by the formulae (PG-1) to (PG-5),

[ solution 4]

A¹To A⁸Each independently represents a hydrogen atom or an alkoxy group having 1 to 5 carbon atoms.

2. The liquid crystal composition according to claim 1, comprising 1 or 2 or more compounds selected from the group consisting of compounds represented by the general formula (N-01), the general formula (N-02), the general formula (N-03), the general formula (N-04), and the general formula (N-05),

[ solution 5]

In the formula, R²¹And R²²Each independently represents an alkyl group having 1 to 8 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, an alkenyl group having 2 to 8 carbon atoms or an alkenyloxy group having 2 to 8 carbon atoms, 1 or 2 or more-CH groups not adjacent to each other₂-each independently may be substituted by-CH ═ CH-, -C ≡ C-, -O-, -CO-, -COO-, or-OCO-, Z¹Each independently represents a single bond, -CH₂CH₂-、-OCH₂-、-CH₂O-、-COO-、-OCO-、-OCF₂-、-CF₂O-, -CH ═ CH-, -CF ═ CF-or-C ≡ C-, and m each independently represents 1 or 2.

3. The liquid crystal composition according to claim 1 or 2, comprising 1 or 2 or more compounds selected from the group consisting of compounds represented by general formulae (NU-01) to (NU-08),

[ solution 6]

In the formula, R^NU11、R^NU12、R^NU21、R^NU22、R^NU31、R^NU32、R^NU41、R^NU42、R^NU51、R^NU52、R^NU61、R^NU62、R^NU71、R^NU72、R^NU81And R^NU82Each independently represents an alkyl group having 1 to 8 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, an alkenyl group having 2 to 8 carbon atoms or an alkenyloxy group having 2 to 8 carbon atoms, 1 or 2 or more-CH groups not adjacent to each other₂-each independently may be substituted by-CH ═ CH-, -C ≡ C-, -O-, -CO-, -COO-, or-OCO-.

4. The liquid crystal composition according to any one of claims 1 to 3, wherein the polymerizable compound represented by the general formula (RM-13) as the first component comprises a polymerizable compound selected from the group consisting of compounds represented by the formulae (RM-131) to (RM-145),

[ solution 7]

[ solution 8]

[ solution 9]

5. The liquid crystal composition according to any one of claims 1 to 4, comprising an antioxidant selected from the group consisting of compounds represented by the formula (H-2-R3), the formula (H-3-R3) and the formula (H-4-M8),

[ solution 10]

6. The liquid crystal composition according to any one of claims 1 to 5, wherein the total content of the first component, the second component, the compound selected from the group consisting of the compounds represented by the general formulae (N-01) to (N-04), and the compound selected from the group consisting of the compounds represented by the general formulae (NU-01) to (NU-08) is 80 to 100% by mass, based on the total amount of the composition.

7. The liquid crystal composition according to any one of claims 1 to 6, wherein the polymerizable compound represented by the general formula (RM-22) as the second component comprises a polymerizable compound selected from the group consisting of compounds represented by the formulae (RM-22O1) to (RM-22O8),

[ solution 11]

8. A liquid crystal display element comprising two substrates and a liquid crystal layer containing the liquid crystal composition according to any one of claims 1 to 7 provided between the two substrates.

9. The liquid crystal display element according to claim 8, which is for active matrix driving.

10. The liquid crystal display element according to claim 8 or 9, which is of a PSA type or a PSVA type.

11. The liquid crystal display element according to any one of claims 8 to 10, wherein at least one of the two substrates does not have an alignment film.