JP2009210980A - Liquid crystal composition containing thiol compound - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid crystal composition capable of manufacturing a color filter substrate having optical compensation capability by solving the problem of significant reduction from a phase difference corresponding to each pixel due to damage of a retardation film in a process such as formation of a liquid crystal layer thickness adjustment layer. <P>SOLUTION: The liquid crystal composition uses a thiol compound having a structure branched at carbons of α-position and/or β-position with respect to thiol group, or a thiol compound having a branched structure in which carbons of α-position and/or β-position have three or more bonds with elements other than hydrogen with respect to thiol group. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a liquid crystal composition excellent in film resistance used for an optical compensation color filter substrate used in a liquid crystal display device and other display devices.

In recent years, liquid crystal display devices have been highly evaluated for their space-saving properties, light weight, and power-saving properties due to their thinness, and recently, they are rapidly spreading to portable devices and television applications. A liquid crystal display device can perform multicolor display by providing a color filter substrate in the panel structure, and generally performs RGB three-color display or six-color display in which RBG pixels for reflection are added thereto. Is.
By the way, as a liquid crystal display device for portable devices, a reflective type or a transflective type liquid crystal display device in which a reflective part is partially formed may be adopted in order to ensure visibility even under strong outdoor light in the daytime. Many. In such a case, in order to effectively utilize the reflected light, a λ / 4 retardation film, a λ / 2 retardation film, or the like is incorporated in the liquid crystal panel configuration as a member that forms part of the absorption-type circularly polarizing plate. .
On the other hand, a liquid crystal display device for TV use is often applied by a method such as combining a retardation film and a linear polarizing plate in a liquid crystal panel configuration for the purpose of further improving visibility in all directions.
However, since such a retardation film usually has the same retardation value in the plane, when the liquid crystal display device in which the retardation film is incorporated is colored by a color filter substrate, the light passing through the display area of each color pixel is transmitted. Due to the difference in wavelength range, a problem that appropriate phase difference control becomes difficult occurs.
For example, in a reflective or transflective liquid crystal display device for portable devices, a retardation film having a retardation amount of λ / 4 (about 138 nm) in a green wavelength region (center wavelength around 550 nm) is combined with a linear polarizing plate. When used as a circularly polarizing plate, the blue wavelength region (center wavelength around 450 nm) is more than λ / 4, and the red wavelength region (center wavelength around 630 nm) is insufficient relative to λ / 4, and red and blue display pixels. In this case, complete circularly polarized light cannot be obtained.
In addition, when a retardation film is designed so that the phase difference is compensated for one of the three colors RGB (wavelength region) in a liquid crystal display device for television applications, compensation is not possible for the other colors (wavelength region). Often there will be completeness. The following factors can be cited as the cause.
(1) The liquid crystal of the cell does not necessarily have the same retardation value in the entire wavelength region, (2) many of the color pigments used in the color filter have optical anisotropy, (3 ) Furthermore, since the degree is different depending on the type of pigment, the phase difference varies depending on the red, green, and blue pixels.
In order to solve such a problem, a method for solving the problem by providing a retardation layer corresponding to each pixel in the liquid crystal cell and performing optical compensation is known.
For example, a retardation element having a retardation amount so as to correspond to display pixels of three colors by depositing polymerization type liquid crystal materials having different film thicknesses or different types has been devised (for example, patents). Reference 1).

However, these conventional methods have a problem that the phase difference is greatly reduced in the process.
For example, in Patent Document 1, as a means for changing the thickness of the retardation layer for each region, a polymerization-type liquid crystal material is formed, and this is exposed to radiation such as ultraviolet rays by changing the irradiation amount for each region. A method of developing with an organic solvent is shown.

  However, in the actual process, it is necessary to further form a liquid crystal layer thickness adjusting layer, a protective layer, and ITO deposition. In this process, the retardation film is damaged, and there arises a problem that the phase difference corresponding to each pixel is greatly reduced.

It is possible to form a phase difference taking into account the reduction in the phase difference in the subsequent process, but it is necessary to increase the film thickness, and it is not possible to easily manufacture this because of the stability in the process. .
JP 2004-191832 A

The present invention has been made to solve the above problems, and an object of the present invention is to provide a liquid crystal composition in which a decrease in retardation hardly occurs with respect to a color filter manufacturing process.

  The inventors of the present invention have a thiol compound having a structure branched at the α-position and / or β-position carbon with respect to the thiol group, that is, the α-position and / or β-position carbon other than hydrogen with respect to the thiol group. It has been found that by using a thiol compound having a branched structure having three or more bonds, it becomes an optical compensation composition in which a retardation decrease due to formation of a color resist or a liquid crystal layer thickness adjusting layer is difficult to occur. It came to be completed.

That is, the present invention includes the following items, for example.
The first aspect of the present invention is a liquid crystal composition characterized by containing a thiol compound having a structure branched at the α-position and / or β-position carbon with respect to the thiol group.

  According to a second aspect of the present invention, there is provided a liquid crystal composition comprising a thiol compound having a structure in which at least one of a substituent at the α-position and / or β-position with respect to the thiol group is an alkyl group.

  A third aspect of the present invention is the liquid crystal composition according to the second aspect, wherein the thiol compound is a thiol compound having a partial structure represented by the formula (1).

（式中、Ｒ₁はメチル基またはエチル基を示し、ｍは０〜２の整数を示し、ｎは０または１の整数を示す。）
本発明の請求項４は、チオール化合物が２個以上のチオール基を有する多官能チオール化合物であることを特徴とする請求項１〜３のいずれかに記載の液晶組成物である。

(In the formula, R ₁ represents a methyl group or an ethyl group, m represents an integer of 0 to 2, and n represents an integer of 0 or 1.)
A fourth aspect of the present invention is the liquid crystal composition according to any one of the first to third aspects, wherein the thiol compound is a polyfunctional thiol compound having two or more thiol groups.

  A fifth aspect of the present invention is the liquid crystal composition according to the third or fourth aspect, wherein the thiol compound is an ester of a carboxylic acid represented by the formula (2) and a polyfunctional alcohol.

（式中、Ｒ₁はメチル基またはエチル基を示し、ｍは０〜２の整数を示し、ｎは０または１の整数を示す。）
本発明の請求項６は、多官能アルコール類が、アルキレングリコール（但し、アルキルレン基の炭素数は２〜１０で枝分かれしていてもよい。）、ジエチレングリコール、グリセリン、ジプロピレングリコール、トリメチロールプロパン、ペンタエリスリトールおよびジペンタエリスリトールから選ばれる化合物の１種または２種以上であることを特徴とする請求項５に記載の液晶組成物である。

(In the formula, R ₁ represents a methyl group or an ethyl group, m represents an integer of 0 to 2, and n represents an integer of 0 or 1.)
According to a sixth aspect of the present invention, the polyfunctional alcohol is an alkylene glycol (however, the alkylene group may be branched with 2 to 10 carbon atoms), diethylene glycol, glycerin, dipropylene glycol, trimethylolpropane. 6. The liquid crystal composition according to claim 5, wherein the liquid crystal composition is one or more of compounds selected from pentaerythritol and dipentaerythritol.

  According to claim 7 of the present invention, the thiol compound is ethylene glycol bis (3-mercaptobutyrate), diethylene glycol bis (3-mercaptobutyrate), butanediol bis (3-mercaptobutyrate), trimethylolpropane tris (3 -Mercaptobutyrate), pentaerythritol tetrakis (3-mercaptobutyrate), dipentaerythritol hexakis (3-mercaptobutyrate), ethylene glycol bis (3-mercaptoisobutyrate), diethylene glycol bis (3-mercaptoisobutyrate) Rate), butanediol bis (3-mercaptoisobutyrate), trimethylolpropane tris (3-mercaptoisobutyrate), pentaerythritol tetrakis (3-mercaptoisobutyrate), di A liquid crystal composition according to claim 6, characterized in that pentaerythritol hexakis (3-mercapto isobutyrate) from one or more selected.

  Claim 8 of the present invention includes at least one photopolymerization initiator selected from α-hydroxyacetophenones, α-aminoacetophenones, and biimidazoles. It is a liquid crystal composition of description.

  The ninth aspect of the present invention is the liquid crystal composition according to any one of the first to eighth aspects, which contains a sensitizer.

  A tenth aspect of the present invention is the liquid crystal composition according to the ninth aspect, wherein the sensitizer is a sensitizer having an absorption wavelength region of 250 to 500 nm.

  The eleventh aspect of the present invention is the liquid crystal composition according to the tenth aspect, wherein the sensitizer is a benzophenone and / or an anthraquinone.

  A twelfth aspect of the present invention is the liquid crystal composition according to any one of the first to eleventh aspects, comprising a polymer, a compound having an ethylenically unsaturated bond, and an organic solvent.

  Due to the use of the liquid crystal composition of the present invention, the phase difference film is damaged in the steps of forming the liquid crystal layer thickness adjusting layer, forming the protective layer, and depositing the ITO at the time of applying the color resist, and greatly from the phase difference corresponding to each pixel. Decreasing retardation of the optical compensation layer is less likely to occur. Also, no residue is generated.

The present invention will be described in further detail.

  The thiol compound having a structure branched at the α-position and / or β-position carbon with respect to the thiol group used in the present invention means that the α-position and / or β-position carbon of the thiol group has three atoms other than hydrogen. A thiol compound having a so-called branched structure bonded to the above, for example, a thiol compound in which at least one of substituents other than the main chain at the α-position and / or β-position with respect to the thiol group is an alkyl group is there. Here, the main chain represents the longest chain structure composed of atoms other than hydrogen containing a thiol group. Among them, a compound having a partial structure represented by the formula (1) is particularly preferable, and a polyfunctional thiol compound having two or more of them is more preferable.

（式中、Ｒ₁はメチル基またはエチル基を示し、ｍは０〜２の整数を示し、ｎは０または１の整数を示す。）
多官能であることにより単官能化合物と比較して、より高感度とすることが可能である。

(In the formula, R ₁ represents a methyl group or an ethyl group, m represents an integer of 0 to 2, and n represents an integer of 0 or 1.)
By being multifunctional, it is possible to achieve higher sensitivity than a monofunctional compound.

  Furthermore, a thiol compound having a partial structure of formula (1) as a carboxylic acid derivative structure of formula (2) is particularly preferable.

（式中、Ｒ₁はメチル基またはエチル基を示し、ｍは０〜２の整数を示し、ｎは０または１の整数を示す。）
式（２）のカルボン酸は、アルコール化合物とエステル結合を有していることが好ましいが、多官能チオールが好ましいことから多官能アルコールとのエステルがより好ましい。多官能アルコールとしては、アルキレングリコール（但し、アルキレン基の炭素数は２〜１０で枝分かれしていてもよい。）、ジエチレングリコール、グリセリン、ジプロピレングリコール、トリメチロールプロパン、ペンタエリスリトール、ジペンタエリスリトール等が例示できる。

(In the formula, R ₁ represents a methyl group or an ethyl group, m represents an integer of 0 to 2, and n represents an integer of 0 or 1.)
The carboxylic acid of the formula (2) preferably has an ester bond with an alcohol compound, but an ester with a polyfunctional alcohol is more preferred because a polyfunctional thiol is preferred. Examples of the polyfunctional alcohol include alkylene glycol (however, the alkylene group may be branched with 2 to 10 carbon atoms), diethylene glycol, glycerin, dipropylene glycol, trimethylolpropane, pentaerythritol, dipentaerythritol and the like. It can be illustrated.

  Specific examples of the thiol compound that can be used in the present invention include the following compounds.

  Examples of the hydrocarbon dithiol include 2,5-hexanedithiol, 2,9-decanedithiol, 1,4-bis (1-mercaptoethyl) benzene, and the like.

  As the carboxylic acid derivative of the formula (2), ethylene glycol bis (3-mercaptobutyrate), diethylene glycol bis (3-mercaptobutyrate), butanediol bis (3-mercaptobutyrate), octanediol bis (3-mercaptobutyrate) Rate), nonanediol bis (3-mercaptobutyrate), trimethylolpropane tris (3-mercaptobutyrate), pentaerythritol tetrakis (3-mercaptobutyrate), dipentaerythritol hexakis (3-mercaptobutyrate), Ethylene glycol bis (2-mercaptopropionate), diethylene glycol bis (2-mercaptopropionate), butanediol bis (2-mercaptopropionate), octanediol bis (2-mercap) Propionate), nonanediol bis (2-mercaptopropionate), trimethylolpropane tris (2-mercaptopropionate), pentaerythritol tetrakis (2-mercaptopropionate), dipentaerythritol hexakis (2-mercaptopro) Pionate), ethylene glycol bis (3-mercaptoisobutyrate), diethylene glycol bis (3-mercaptoisobutyrate), butanediol bis (3-mercaptoisobutyrate), octanediol bis (3-mercaptoisobutyrate) Nonanediol bis (3-mercaptoisobutyrate), trimethylolpropane tris (3-mercaptoisobutyrate), pentaerythritol tetrakis (3-mercaptoisobutyrate), dipe Taerythritol hexakis (3-mercaptoisobutyrate), ethylene glycol bis (2-mercaptoisobutyrate), diethylene glycol bis (2-mercaptoisobutyrate), butanediol bis (2-mercaptoisobutyrate), octanediol Bis (2-mercaptoisobutyrate), nonanediol bis (2-mercaptoisobutyrate), trimethylolpropane tris (2-mercaptoisobutyrate), pentaerythritol tetrakis (2-mercaptoisobutyrate), dipentaerythritol Hexakis (2-mercaptoisobutyrate), ethylene glycol bis (4-mercaptovalerate), diethylene glycol bis (4-mercaptovalerate), butanediol bis (4-mercaptoba Relate), octanediol bis (4-mercaptovalerate), nonanediol bis (4-mercaptovalerate), trimethylolpropane tris (4-mercaptovalerate), pentaerythritol tetrakis (4-mercaptovalerate), dipenta Erythritol hexakis (4-mercaptovalerate), ethylene glycol bis (3-mercaptovalerate), diethylene glycol bis (3-mercaptovalerate), butanediol bis (3-mercaptovalerate), octanediol bis (3-mercapto) Valerate), nonanediol bis (3-mercaptovalerate), trimethylolpropane tris (3-mercaptovalerate), pentaerythritol tetrakis (3-mercaptovalerate), dipen Erythritol hexakis (3-mercapto valerate) and the like.

  As compounds containing an alcohol having the structure of formula (1), di (1-mercaptoethyl ester) phthalate, di (2-mercaptopropyl ester) phthalate, di (3-mercaptobutyl ester) phthalate, diphthalate (3-mercaptoisobutyl ester) and the like can be exemplified.

  Preferably, ethylene glycol bis (3-mercaptobutyrate), diethylene glycol bis (3-mercaptobutyrate), butanediol bis (3-mercaptobutyrate), octanediol bis (3-mercaptobutyrate), trimethylolpropane tris ( 3-mercaptobutyrate), pentaerythritol tetrakis (3-mercaptobutyrate), dipentaerythritol hexakis (3-mercaptobutyrate), ethylene glycol bis (3-mercaptoisobutyrate), diethylene glycol bis (3-mercaptoiso) Butyrate), butanediol bis (3-mercaptoisobutyrate), octanediol bis (3-mercaptoisobutyrate), trimethylolpropane tris (3-mercaptoisobutyrate) Over g), pentaerythritol tetrakis (3-mercapto isobutyrate), dipentaerythritol hexakis (3-mercapto isobutyrate) and the like.

  More preferably, ethylene glycol bis (3-mercaptobutyrate), butanediol bis (3-mercaptobutyrate), trimethylolpropane tris (3-mercaptobutyrate), ethylene glycol bis (3-mercaptoisobutyrate), Butanediol bis (3-mercaptoisobutyrate) and trimethylolpropane tris (3-mercaptoisobutyrate) are desirable from the viewpoint of polymerization initiation ability and storage stability.

  These thiol compounds can be used alone or in combination of two or more.

  In this invention, a thiol compound is mix | blended so that it may generally become 1-200 mass parts with respect to 100 mass parts of compounds which have an ethylenically unsaturated bond, Preferably it is 10-100 mass parts. If the amount is too small, polymerization initiation may not proceed efficiently. If the amount is too large, improvement of the polymerization initiation function cannot be expected, and physical properties may be adversely affected.

  Usually, photocuring by radical polymerization is difficult to completely cure at the interface with air due to inhibition of polymerization by oxygen in the air. Therefore, in general, an air blocking layer such as a cover film is provided so that oxygen does not touch the surface, or photocuring is performed in an inert gas atmosphere such as argon gas or nitrogen. However, the liquid crystal composition of the present invention exhibits sufficient curability regardless of the presence or absence of oxygen.

  As the photopolymerization initiator used in the present invention, a general photopolymerization initiator can be used. Preferred examples include α-hydroxyacetophenones, α-aminoacetophenones, and biimidazoles. .

Examples of the α-hydroxyacetophenones used in the present invention include 2-hydroxy-2-methyl-1-phenylpropan-1-one, 2-hydroxy-2-methyl-1-phenylbutan-1-one, -(4-methylphenyl) -2-hydroxy-2-methylpropan-1-one, 2-hydroxy-propan-1-one, 1- (4-isopropylphenyl) -2-methylpropan-1-one, -(4-Butylphenyl) -2-hydroxy-2-methylpropan-1-one, 2-hydroxy-2-methyl-1- (4-octylphenyl) propan-1-one, 1- (4-dodecylphenyl) ) -2-Methylpropan-1-one, 1- (4-methoxyphenyl) -2-methylpropan-1-one, 1- (4-methylthiophenyl) -2- Tylpropan-1-one, 1- (4-chlorophenyl) -2-hydroxy-2-methylpropan-1-one, 1- (4-bromophenyl) -2-hydroxy-2-methylpropan-1-one, 2 -Hydroxy-1- (4-hydroxyphenyl) -2-methylpropan-1-one, 1- (4-dimethylaminophenyl) -2-hydroxy-2-methylpropan-1-one, 1- (4-carbo Ethoxyphenyl) -2-hydroxy-2-methylpropan-1-one, 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-1- (4- (2-hydroxyethoxy) -phenyl) -2-methylpropane-1- ON.

  Examples of α-aminoacetophenones used in the present invention include 2-dimethylamino-2-methyl-1-phenylpropan-1-one, 2-diethylamino-2-methyl-1-phenylpropan-1-one, 2-methyl-2-morpholino-1-phenylpropan-1-one, 2-dimethylamino-2-methyl-1- (4-methylphenyl) propan-1-one, 2-dimethylamino-1- (4- Ethylphenyl) -2-methylpropan-1-one, 2-dimethylamino-1- (4-isopropylphenyl) -2-methylpropan-1-one, 1- (4-butylphenyl) -2-dimethylamino- 2-methylpropan-1-one, 2-dimethylamino-1- (4-methoxyphenyl) -2-methylpropan-1-one, 2-dimethylamino 2-methyl-1- (4-methylthiophenyl) propan-1-one, 2-methyl-1- (4-methylthiophenyl) -2-morpholino-propan-1-one, 2-benzyl-2-dimethylamino Examples include -1- (4-morpholinophenyl) -butan-1-one and 2-benzyl-2-dimethylamino-1- (4-dimethylaminophenyl) -butan-1-one.

  The biimidazoles used in the present invention are, for example, 2,2′-bis (2-chlorophenyl) -4, 4 ′, 5,5′-tetraphenyl-1,2′-biimidazole, 2,2 ′. -Bis (2-chlorophenyl) -4,4 ', 5,5'-tetra (ethoxyphenyl) -1,2'-biimidazole, 2,2'-bis (2-chlorophenyl) -4,4', 5 5′-tetra (4-bromophenyl) -1,2′-biimidazole, 2,2′-bis (2-chlorophenyl) -4, 4 ′, 5,5′-tetra (4-methylphenyl)- 1,2′-biimidazole, 2,2′-bis (2-chlorophenyl) -4,4 ′, 5,5′-tetra (4-ethylphenyl) -1,2′-biimidazole, 2,2 ′ -Bis (2-chlorophenyl) -4,4 ', 5,5'-tetra (4-butylphenyl)- 2'-biimidazole, 2,2'-bis (2-chlorophenyl) -4,4 ', 5,5'-tetra (4-octylphenyl) -1,2'-biimidazole, 2,2'- Bis (2-chlorophenyl) -4,4 ′, 5,5′-tetra (4-methoxyphenyl) -1,2′-biimidazole, 2,2′-bis (2-chlorophenyl) -4,4 ′, 5,5′-tetra (3-methoxyphenyl) -1,2′-biimidazole, 2,2′-bis (2,4-dichlorophenyl) -4, 4 ′, 5,5′-tetraphenyl-1, 2'-biimidazole, 2,2'-bis (2-fluorophenyl) -4,4 ', 5,5'-tetra (3-methoxyphenyl) -1,2'-biimidazole, 2,2'- Bis (2,6-difluorophenyl) -4,4 ′, 5,5′-tetra (3-methoxyphenyl) -1,2′-bi Imidazole, 2,2'-bis (2-methylphenyl) -4,4 ', 5,5'-tetraphenyl-1,2'-bi imidazole.

  Other photopolymerization initiators include benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzylmethyl ketal, α-halogenoacetophenones, methylphenylglyoxylate, benzyl, anthraquinone, phenanthrenequinone, camphorquinone, acyl Phosphine oxide, bisacyl phosphine oxide, and the like can also be used.

  These photopolymerization initiators can be used alone or in combination of two or more. In this invention, a photoinitiator is mix | blended so that it may become 5-100 mass parts generally with respect to 100 mass parts of compounds which have an ethylenically unsaturated bond, Preferably it is 10-50 mass parts.

Furthermore, a sensitizer can be used to increase the sensitivity.
As the sensitizer, a compound that is excited by absorbing light from a light source can be used. Examples of these compounds include compounds such as benzophenones, acetophenones, thioxanthones, anthraquinones, coumarins, ketocoumarins, and triphenylpyryliums.

  These compounds can be used alone or in combination of two or more, and can be determined in consideration of the light emission pattern of the light source used.

  Specific examples of the sensitizer are given below. Benzophenone, 4-methylbenzophenone, 4-dimethylaminobenzophenone, 4,4'-dimethylaminobenzophenone, 4,4'-diethylaminobenzophenone, 2,4-diethylthioxanthone, 2-methylthioxanthone, isopropylthioxanthone, anthraquinone, ethylanthra Examples include quinone, chloroanthraquinone, hydroxymethylanthraquinone, aminoanthraquinone, methylaminoanthraquinone, aceanthrenequinone, acenaphthenequinone, coumarin, 7-diethylaminocoumarin, and ethyl 4-dimethylaminobenzoate.

  In this invention, a sensitizer is mix | blended so that it may generally become 1-60 mass parts with respect to 100 mass parts of compounds which have an ethylenically unsaturated bond, Preferably it is 2-30 mass parts. If the amount is too small, the sensitization effect may not be obtained. If the amount is too large, the light transmission efficiency deteriorates due to the light absorption of the sensitizer, and the polymerization initiation efficiency may decrease.

The polymer used in the present invention is a polymer capable of forming a uniform transparent film having a thickness of 1 micron or more. Preferably, it is a polymer having a transmittance of 80% or more, more preferably 95% or more in the entire wavelength region of 400 to 700 nm in the visible light region. The polymer may be a thermosetting resin or a thermoplastic. Resins, photosensitive resins, etc., such as polyacrylates, poly-α-alkyl acrylates, polyamides, polyvinyl acetals, polyurethanes, polycarbonates, polystyrenes, polyvinyl esters, phenol resins, epoxy resins, novolac resins Polymers such as alkyd resins and copolymers can be used alone or as a mixture of two or more. Further, these high molecular polymers may have an ethylenically unsaturated bond group capable of radical polymerization for the purpose of promoting the curing reaction of the liquid crystal composition of the present invention or improving the properties of the cured product. However, in color filter applications, high-temperature treatment and treatment with various solvents or chemicals are performed in the subsequent steps of production, and therefore, a polymer having excellent heat resistance, stability over time, etc. should be used. preferable. These high molecular polymers may or may not be used.

  As the compound having an ethylenically unsaturated bond used in the present invention, a compound that is generally called a monomer or oligomer and capable of radical polymerization (or crosslinking) reaction is used, and (meth) acrylic acid, methyl (meth) acrylate, Various (meth) acrylic esters such as butyl (meth) acrylate, benzyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, ethylene glycol di (meth) acrylate, trimethylolpropane Tri (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythrole tetra (meth) acrylate, styrene, divinylbenzene, (meth) acrylamide, vinyl acetate, N-hydroxymethyl (meth) acrylami , Dipentaerythritol hexa (meth) acrylate, melamine (meth) acrylate, epoxy (meth) acrylate prepolymer, and the like. However, it is preferable to use a polyfunctional (meth) acrylic monomer in terms of exposure sensitivity and various resistances after the effect. These compounds having an ethylenically unsaturated bond may be used alone or in combination of two or more. Further, it may not be used.

  Furthermore, a volatile solvent may be added to the liquid crystal composition of the present invention for the purpose of adjusting the viscosity. Examples of the volatile solvent include alcohols, ketones, esters and the like. For example, methanol, ethanol, toluene, cyclohexane, isophorone, cellosolve acetate, diethylene glycol dimethyl ether, ethylene glycol diethyl ether, xylene, ethylbenzene, methyl cellosolve, ethyl cellosolve, butyl cellosolve, propylene glycol monomethyl ether, isoamyl acetate, ethyl lactate, methyl ethyl ketone, acetone, cyclohexanone Etc., and may be used alone or in admixture of two or more.

  Further, the liquid crystal composition of the present invention may further comprise a leveling agent, an antifoaming agent, a surfactant, a plasticizer, a flame retardant, an antioxidant, an ultraviolet absorber, an antifungal agent, an antistatic agent, a magnetic substance, depending on the purpose. A conductive material or the like may be added. The liquid crystal composition of the present invention can contain a thermal polymerization inhibitor for the purpose of preventing polymerization during storage. Specific examples of the thermal polymerization inhibitor include p-methoxyphenol, hydroquinone, catechol, tert-butylcatechol, phenothiazine, and methoquinone.

  The liquid crystal composition of the present invention has a dry film thickness of 0.5 to 3 μm on a substrate such as glass, aluminum, PET film, and polyester film by a coating method such as spinner coating, spray coating, dip coating, and calendar coating. It is applied so that it becomes. The applied liquid crystal composition is dried with a hot air oven or a hot plate as necessary, generally at 60 to 100 ° C. for 10 to 30 minutes. If the temperature at this time is too high or the drying time is too long, partial polymerization or crosslinking occurs, which is not preferable. Moreover, you may dry under reduced pressure.

  The dried coating film is exposed to ultraviolet light through a photomask having a pattern. As the light source, an ultra-high pressure mercury lamp, a metal halide lamp, a xenon lamp, or the like is generally used, and a filter having heat ray cutting property or wavelength selectivity may be used depending on the application or the type of substrate. Further, a heat treatment (post-bake) may be performed for the purpose of imparting chemical or physical resistance to the pattern formed thereafter. The conditions for the heat treatment are preferably conditions that do not impair the color characteristics of the color filter, and it is particularly preferable to carry out the treatment at 150 to 250 ° C. for 10 to 120 minutes.

  EXAMPLES Hereinafter, although this invention is demonstrated based on an Example, this invention is not restrict | limited at all by an Example. In the examples, “part” means “part by mass” and “%” means “% by mass”. The prepared photosensitive liquid crystal composition is referred to as a resist for convenience.

<Example 1>
A mixture having the following composition was stirred and mixed to be uniform, and a resist obtained by filtering with a 0.6 μm filter was applied on a glass substrate with a spin coater so that the dry film thickness was 1.7 μm. The plate was heated and dried at 90 ° C. for 2 minutes on a hot plate to obtain an optical compensation substrate.

Horizontally-aligned polymerizable liquid crystal 18.3 parts (“Palocolor LC 242” manufactured by BASF Japan Ltd.)
Photopolymerization initiator 0.2 part ("Irgacure 907" manufactured by Ciba Specialty Chemicals Co., Ltd.)
0.7 parts of thiol compound (“TMMP” manufactured by Sakai Chemical Industry Co., Ltd.)
Surfactant 3.0 parts (Bikchemy "BYK330" 2% cyclohexanone solution)
77.0 parts of cyclohexanone Next, the liquid crystal alignment substrate was exposed to ultraviolet rays using an ultrahigh pressure mercury lamp. The irradiation amount of ultraviolet rays was 200 mJ / cm ² .
Subsequently, the substrate was put in a clean oven and baked at 230 ° C. for 40 minutes to obtain a retardation thin film substrate.
Next, a liquid crystal layer thickness adjusting layer was applied.
Table 1 shows the phase difference before and after application of the liquid crystal layer thickness adjusting layer. A substrate was prepared in the same manner for a resist containing no thiol compound and compared.

＜実施例２＞
実施例１と同様に位相差薄膜基板を作成する。
次にカラーレジストをスピンコーターで乾燥膜厚が１．０μｍになるように塗布した後に、クリーンオーブン中７０℃で２０分間加熱乾燥し塗布基板を得た。この基板を室温まで冷却後、超高圧水銀灯を用い、フォトマスクを介して紫外線を露光した。その後、この基板を２３℃の炭酸ナトリウム水溶液を用いてスプレー現像した後、イオン交換水で洗浄し、風乾した。さらに、クリーンオーブン中２３０℃で３０分間焼成を行なった。
位相差の変化と残渣の有無を表２に示す。実施例１と同様にチオール化合物無添加品を比較として用いた。

<Example 2>
A retardation film substrate is prepared in the same manner as in Example 1.
Next, a color resist was applied by a spin coater so that the dry film thickness was 1.0 μm, and then dried by heating in a clean oven at 70 ° C. for 20 minutes to obtain a coated substrate. After cooling the substrate to room temperature, ultraviolet rays were exposed through a photomask using an ultrahigh pressure mercury lamp. Thereafter, the substrate was spray-developed using a sodium carbonate aqueous solution at 23 ° C., washed with ion-exchanged water, and air-dried. Furthermore, baking was performed at 230 ° C. for 30 minutes in a clean oven.
Table 2 shows the change in phase difference and the presence or absence of residue. As in Example 1, a thiol compound-free product was used as a comparison.

表１、２の結果から明らかなように、本発明の液晶組成物を用いることによって、液晶層厚調整層、カラーレジストによる位相差低下をほぼ生じない優れた光学補償能を有するカラーフィルタ基板を得る事ができる。

As is clear from the results of Tables 1 and 2, by using the liquid crystal composition of the present invention, a color filter substrate having an excellent optical compensation ability that hardly causes a retardation decrease due to a liquid crystal layer thickness adjusting layer and a color resist. I can get it.

Claims (13)

  A liquid crystal composition comprising a thiol compound having a structure branched by carbon at α-position and / or β-position with respect to a thiol group.   2. The liquid crystal composition according to claim 1, comprising a thiol compound having a structure in which at least one of a substituent at the α-position and / or β-position with respect to the thiol group is an alkyl group. The liquid crystal composition according to claim 1 or 2, wherein the thiol compound is a thiol compound having a partial structure represented by the formula (1).

(In the formula, R ₁ represents a methyl group or an ethyl group, m represents an integer of 0 to 2, and n represents an integer of 0 or 1.)   The liquid crystal composition according to claim 1, wherein the thiol compound is a polyfunctional thiol compound having two or more thiol groups. The liquid crystal composition according to claim 3 or 4, wherein the thiol compound is an ester of a carboxylic acid represented by the formula (2) and a polyfunctional alcohol.

(Wherein R1 represents a methyl group or an ethyl group, m represents an integer of 0 to 2, and n represents an integer of 0 or 1)   The polyfunctional alcohol is an alkylene glycol (provided that the alkylene group may be branched with 2 to 10 carbon atoms), diethylene glycol, glycerin, dipropylene glycol, trimethylolpropane, pentaerythritol and dipentaerythritol. 6. The liquid crystal composition according to claim 5, wherein the liquid crystal composition is one type or two or more types of selected compounds.   Thiol compounds are ethylene glycol bis (3-mercaptobutyrate), diethylene glycol bis (3-mercaptobutyrate), butanediol bis (3-mercaptobutyrate), trimethylolpropane tris (3-mercaptobutyrate), pentaerythritol. Tetrakis (3-mercaptobutyrate), dipentaerythritol hexakis (3-mercaptobutyrate), ethylene glycol bis (3-mercaptoisobutyrate), diethylene glycol bis (3-mercaptoisobutyrate), butanediol bis (3 -Mercaptoisobutyrate), trimethylolpropane tris (3-mercaptoisobutyrate), pentaerythritol tetrakis (3-mercaptoisobutyrate), dipentaerythritol Kisakisu one selected from (3-mercapto isobutyrate) or a liquid crystal composition according to claim 6, characterized in that two or more kinds.   The liquid crystal composition according to claim 1, comprising at least one photopolymerization initiator selected from α-hydroxyacetophenones, α-aminoacetophenones, and biimidazoles.   The liquid crystal composition according to claim 1, comprising a sensitizer.   The liquid crystal composition according to claim 9, wherein the sensitizer is a sensitizer having an absorption wavelength region of 250 to 500 nm.   The liquid crystal composition according to claim 10, wherein the sensitizer is a benzophenone and / or an anthraquinone.   The liquid crystal composition according to claim 1, comprising a polymer, a compound having an ethylenically unsaturated bond, and an organic solvent.   In a color filter substrate in which the liquid crystal composition includes at least a substrate and a color filter layer provided on the substrate, the color filter layer includes a plurality of display pixels of two or more colors, and a lower portion of the color filter layer The liquid crystal composition according to any one of claims 1 to 12, wherein a layer of the liquid crystal composition is provided on an upper portion, and the color filter substrate has optical compensation performance by the liquid crystal composition.