JP2001059055A - Liquid crystal display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a photoresist composition for forming spacers useful for a liquid crystal display device of a high display quality by including a photosensitive resin and solid fine particles having a functional group reactive therewith. SOLUTION: This photoresist composition comprises (A) a photosensitive resin and (B) solid fine particles having a functional group reactive with the component A. The component B can be obtained by treating solid fine particles with a compound having the functional group reactive with the photosensitive resin (preferably a double bond, an SH group or the like). For example, the liquid crystal display device of a high display quality with slight movement of spacers can be produced by forming a color filter 23 comprising a black matrix 21 and each pixel 22, a flattened film 24, a transparent electrode 5 and an oriented film 25 on a transparent substrate 12, forming the transparent electrode 5 on a transparent substrate 11, forming the oriented film 25 on the resultant transparent electrode 5, coating the whole surfaces of the oriented films 25 with the composition, forming films 26 of the composition, carrying out the exposure and developing treatment and thereby capable of making the films of the composition remain in nonpixel regions of the liquid crystal display device.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a liquid crystal display device. More specifically, the present invention relates to a liquid crystal display device having a spacer formed by photolithography.

[0002]

2. Description of the Related Art Conventionally, when LCDs are manufactured, wet or dry spraying is performed to spray spacers on a substrate.
However, since the spacers are also dispersedly arranged on the pixels, the portions where the spacers are present are not displayed. In addition, light leakage occurs such that light from the backlight passes through the spacers themselves and around the spacers due to disorder in the alignment of the liquid crystal. However, as a result, there is a problem that the display quality is largely reduced due to a decrease in the contrast and roughness of the LCD.

In order to accurately arrange or form a spacer in a non-pixel region other than a pixel, it is conventionally known to use a photolithography technique. For example,
Japanese Patent Application Laid-Open No. 9-160009 discloses a method in which a spacer composed of solid fine particles is mixed with a photoresist, exposed and developed by a photolithography technique, and the spacer is present on a black matrix. Japanese Patent Application Laid-Open No. 10-73827 discloses a method of forming a columnar spacer made of a photosensitive resin on a black matrix by a photolithography technique.

[0004]

In recent years, liquid crystal display elements have been used for mobile information terminals such as mobile phones and pagers, mobile communication systems, and car navigation systems, taking advantage of their lightweight and thin characteristics. I have. In these applications, the spacer is more likely to move due to a load such as vibration and impact due to the movement, as compared with applications such as desktop personal computers, word processors, and TVs.

In recent years, the screen size of monitors, personal computers, TVs, and the like has been remarkably enlarged, and the substrate size has become larger (for example, 550 × 650 mm or more) or the panel size has become larger (for example, 14 or more). If it is greater than inch, the electrode substrate is likely to bend, and the spacer is likely to move due to vibration or impact on the liquid crystal display device during the manufacturing process of the liquid crystal display device.

For example, in the method disclosed in Japanese Patent Application Laid-Open No. 9-160009, as described above, the spacer is moved, and the thickness of the liquid crystal layer cannot be kept uniform and constant. When the spacer moves, there is a problem that the contrast is reduced, and the meaning of arranging and forming the spacer only in the non-pixel region by the photolithography technique is lost. on the other hand,
In the method disclosed in Japanese Patent Application Laid-Open No. 10-73827, there is no problem of spacer movement because solid fine particles are not used. However, photolithography must be performed many times to form columnar spacers, which is complicated. Costs are also high.

Accordingly, an object of the present invention is to provide a liquid crystal display device of high display quality, in which spacers made of solid fine particles are accurately formed only in non-pixel regions by using photolithography technology, and in which the movement of the spacers is small. To provide.

[0008]

In order to solve the above problems, the present invention provides an invention having the following configuration. (1) A photoresist composition for forming a spacer, comprising a photosensitive resin and solid fine particles having a functional group capable of reacting with the photosensitive resin. (2) A composition for a black matrix of a color filter, comprising a photosensitive resin, a light-shielding substance, and solid fine particles having a functional group capable of reacting with the photosensitive resin.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the present invention, solid fine particles having a functional group capable of reacting with a photosensitive resin and acting as a spacer are used together with the photosensitive resin in order to prevent the movement of the spacer composed of the solid fine particles. Specifically, the following two technologies are proposed. (1) a photosensitive resin, including solid fine particles having a functional group capable of reacting with the photosensitive resin, using a photoresist composition for spacer formation, the photoresist composition in a non-pixel region of a liquid crystal display device Exposure and development are carried out by photolithography so that the film remains. According to this, since the photolithography technique is used, a spacer can be accurately formed only in the non-pixel region, and a functional group capable of reacting with the photosensitive resin of the solid fine particles chemically bonds to the photosensitive resin. (Fine particles) are firmly fixed, and the spacer does not easily move even when vibration or impact is applied to the liquid crystal display device, so that the image quality is improved.

(2) Using a composition for a black matrix of a color filter, comprising a photosensitive resin, a light-shielding substance, and solid fine particles having a functional group capable of reacting with the photosensitive resin, using a photolithography technique. , Exposure and development processes to form a black matrix of the liquid crystal display device. According to this, since the photolithography technique is used, the black matrix (that is, the non-pixel area) is accurately formed.
The spacers (solid fine particles) are firmly fixed because a functional group capable of reacting with the photosensitive resin of the solid fine particles and the photosensitive resin are chemically bonded, so that the spacers (solid fine particles) are firmly fixed. Even if vibration or shock is applied, the spacer is hard to move, and the image quality is improved.

Hereinafter, the above (1) and (2) will be specifically described in order. [When the photoresist composition for forming a spacer of (1) is used] The photoresist composition for forming a spacer of (1) is:
It includes a photosensitive resin and solid fine particles having a functional group capable of reacting with the photosensitive resin. A photosensitive resin is a resin having a property of changing its solubility in a developer by irradiating light having a wavelength within a range from an ultraviolet light region to a visible light region, and is classified into a negative type and a positive type. .

Representative examples of the negative photosensitive resin include a photosensitive resin containing a photopolymerizable compound having at least one ethylenically unsaturated double bond and a photopolymerization initiator. Examples of the photopolymerizable compound include known (meth) acrylate compounds. Specifically, various polyester (meth) acrylates, epoxy (meth) acrylates, urethane (meth) acrylates, urethane (meth) acrylates having polyacrylamide as a skeleton,
Oligomers of (meth) acrylate compounds such as urethane (meth) acrylate having polybutadiene as a skeleton; alkoxy polyethylene glycol (n = 1 to 1)
0) mono (meth) acrylate, alkoxy polypropylene glycol (n = 1 to 10) mono (meth) acrylate, phenyl (meth) acrylate, benzyl (meth) acrylate, cyclohexyl (meth) acrylate, lauryl (meth) acrylate, octyl ( Meta)
Acrylate, (meth) acrylic acid, itaconic acid, acrylamide, N, N'-dialkylacrylamide,
N, N′-dialkylethyl (meth) acrylic acid,
Monofunctional monomers such as N, N'-dialkylaminoalkyl (meth) acrylate, N-vinylpyrrolidone, (meth) acryloylmorpholine, isobornyl (meth) acrylate; ethylene diglycol (meth) acrylate, propylene diglycol (meth) ) Acrylates, butylene diglycol (meth) acrylates, hexylene diglycol (meth) acrylates, neopentyl glycol diacrylate, polyethylene glycol di (meth) acrylates, polypropylene glycol di (meth) acrylates, trimethylolpropane Tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol hexa (meth) acrylate Dipentaerythritol penta (meth) acrylate, ethylene oxide-modified trimethylolpropane tri (meth) acrylate, ethylene oxide-modified pentaerythritol tetra (meth) acrylate, ethylene oxide-modified glycerol (meth) acrylate, glycerol di (meth) acrylate, Glycerol tri (meth) acrylate, aryl (meth) acrylate, methallyl (meth) acrylate, triallyl (iso) cyanurate, triallyl trimerite, divinylbenzenes, di (meth) allyl phthalate, di (meth) acryloyloxyethyl Polyfunctional monomers such as phthalate, vinylphenyl (meth) allyl ether, methylenebis (meth) allylacrylamide; poly (meth) acyl Le esters, poly (meth) acrylamide, polystyrene and poly end of the polymer of vinyl acetate compound having a polymerizable double bond such photopolymerizable macromers of the like.
These photopolymerizable compounds may be used alone or in combination of two or more.

These photopolymerizable compounds are preferably used in a proportion of not less than 60% by weight in the photosensitive resin. As the photopolymerization initiator, known ones can be used,
For example, benzyl, benzoin ether, benzoin isobutyl ether, benzoin isopropyl ether,
Benzophenone, benzoylbenzoic acid, methyl benzoylbenzoate, 4-benzoyl-4'-methyldiphenylsulfide, benzylmethylketal, dimethylaminomethylbenzoate, 2-n-butoxyethyl-4-
Dimethylaminobenzoate, isoamyl p-dimethylaminobenzoate, 3,3'-dimethyl-4-methoxybenzophenone, methylobenzoylformate, 2-methyl-1- (4- (methylthio) phenyl) -2-morpholinopropane -1-one, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butan-1-one, 1- (4-dodecylphenyl) -2-hydroxy-2-methylpropane-1- On, 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-
2-methyl-1-phenylpropan-1-one, 1-
(4-Isopropylphenyl) -2-hydroxy-2-
Methylpropan-1-one, 2-chlorothioxanthone, 2,4-diethylthioxanthone, 2,4-diisopropylthioxanthone, 2,4-dimethylthioxanthone, isopropylthioxanthone, 1-chloro-4-
And propoxythioxanthone. These photopolymerization initiators may be used alone or in combination of two or more.

These photopolymerization initiators are preferably used in the range of 0.5 to 30% by weight, more preferably 2 to 15% by weight, based on the above photopolymerizable compound. The negative photosensitive resin may contain other polymer binders as necessary, but is preferably used in a proportion of 40% by weight or less in the photosensitive resin. Examples of the positive photosensitive resin include o-naphthoquinonediazidosulfonic acid novolak ester, o-diazonaphthoquinonesulfonic acid novolak ester, polyphenyl (meth) acrylate,
Poly (p-formyloxystyrene), novolak / dihydropyridine compound, novolak / nifedipine, N-
t-butyloxycarbonylmaleimide-styrene copolymer and the like. Further, a substance whose main chain of the polymer is cleaved by ultraviolet light, for example, polymethyl methacrylate,
Polymethylisopropenyl ketone, poly (o-nitrobenzaldehyde glycol acetal) and the like can also be used as the positive photosensitive resin.

The fine solid particles having a functional group capable of reacting with the photosensitive resin can be obtained by treating the solid fine particles with a compound having a functional group capable of reacting with the photosensitive resin. Functional groups that can react with the photosensitive resin include a double bond group, a carboxyl group, an amino group, an SH group, an epoxy group,
Isocyanate group, hydroxyl group and the like, preferably,
Double bond group which easily reacts with double bond group of photosensitive resin, SH
And particularly preferably a double bond group. These functional groups capable of reacting with the photosensitive resin are preferably present on the surface of the solid fine particles because the reaction with the photosensitive resin is easy.

The average particle diameter of the solid fine particles is usually 0.5
To 100 μm, preferably 1 to 50 μm, more preferably 1.5 to 30 μm. If the average particle diameter is out of the above range, it is a region that is not used as a spacer of the liquid crystal display device. The coefficient of variation of the particle diameter of the solid fine particles is preferably 10% or less, more preferably 8% or less, and further preferably 6% or less. When the variation coefficient of the particle diameter exceeds 10%, it becomes difficult to keep the thickness of the liquid crystal layer in the liquid crystal display device uniform and constant, and image unevenness is likely to occur.

The shape of the solid fine particles is preferably spherical in order to make the gap distance of the liquid crystal display device uniform. This is because if the particles are spherical, they can have a constant or nearly constant particle size in all or almost all directions. Such spherical fine particles are produced by suspension polymerization, emulsion polymerization, dispersion polymerization, seed polymerization, or the like.

The solid fine particles include various types, and are not particularly limited. Examples thereof include organic crosslinked polymer particles, inorganic particles, and organic / inorganic composite particles. Among these, vinyl-based crosslinked polymer particles and organic-inorganic composite particles are preferable because they can easily prevent damage to the electrode substrate, the alignment film or the color filter, and can easily obtain the uniformity of the gap distance between the two electrode substrates. Body particles are most preferred.

The organic cross-linked polymer particles are not particularly limited. For example, a cross-linkable vinyl monomer having two or more vinyl groups such as divinylbenzene is polymerized alone or is co-polymerized with another vinyl monomer. And vinyl-based crosslinked polymer particles such as divinylbenzene crosslinked resin particles obtained by polymerization (see JP-A-1-144429).

The inorganic particles are not particularly restricted but include, for example, spherical fine particles such as glass, silica and alumina. The organic-inorganic composite particles are composite particles comprising an organic portion and an inorganic portion. In the organic-inorganic composite particles, the ratio of the inorganic portion is not particularly limited, but is, for example, preferably 10 to 90 wt%, more preferably 10 to 90 wt%, in terms of inorganic oxide, based on the weight of the organic-inorganic composite particles. Is 2
It is in the range of 5 to 85 wt%, more preferably 30 to 80 wt%. The term “inorganic oxide equivalent” indicating the proportion of the inorganic portion refers to the percentage by weight determined by measuring the weight before and after firing the organic-inorganic composite particles at a high temperature (for example, 1000 ° C.) in an oxidizing atmosphere such as air. It is. When the ratio of the inorganic portion of the organic-inorganic composite particles falls below the above range in terms of inorganic oxide, the organic-inorganic composite particles become softer, and the number of particles dispersed on the electrode substrate may increase. When the film is too hard, the alignment film in the liquid crystal display device may be damaged and the TFT may be easily broken.

The organic-inorganic composite particles are not particularly limited, and include, for example, an organic polymer skeleton and an organic silicon in which a silicon atom is directly chemically bonded to at least one carbon atom in the organic polymer skeleton. And the amount of SiO ₂ constituting the polysiloxane skeleton is preferably 10 to 10.
Organic-inorganic composite particles in a range of 90 wt%, more preferably 25 to 85 wt%, and most preferably 30 to 80 wt%. As the organic polymer skeleton, a vinyl-based polymer is preferable because it provides high restoring property in which gap control can be controlled.

The method for producing the organic-inorganic composite particles is not particularly limited, and examples thereof include the following production method including a condensation step, a polymerization step and a heat treatment step.
The condensation step is a step of performing hydrolysis and condensation using a silicon compound having a radical polymerizable group. The radical polymerizable group-containing silicon compound has the following general formula (1):

[0023]

Embedded image

(Wherein, R ^a represents a hydrogen atom or a methyl group; R ^b has 1 to 5 carbon atoms which may have a substituent)
R ⁱ represents a monovalent organic group having 1 to 20 carbon atoms; R ^c represents a hydrogen atom and 1 to 20 carbon atoms;
And at least one monovalent group selected from the group consisting of an alkyl group having 5 and an acyl group having 2 to 5 carbon atoms. l is 0
Or 1. ) And the following general formula (2):

[0025]

Embedded image

(Where R ^d represents a hydrogen atom or a methyl group; R ^j represents a monovalent organic group having 1 to 20 carbon atoms; R ^e represents a hydrogen atom and 1 to 5 carbon atoms) And at least one monovalent group selected from the group consisting of an alkyl group and an acyl group having 2 to 5 carbon atoms. M is 0 or 1.) and the following general formula (3):

[0027]

Embedded image

(Wherein, R ^f represents a hydrogen atom or a methyl group; R ^g represents an optionally substituted C 1 -C 1)
R ^k represents a monovalent organic group having 1 to 20 carbon atoms; R ^h represents a hydrogen atom and a C 1 to C 20 organic group;
And at least one monovalent group selected from the group consisting of an alkyl group having 5 and an acyl group having 2 to 5 carbon atoms. n is 0
Or 1. ) Is preferably a compound represented by at least one general formula selected from the group consisting of or a derivative thereof.

The polymerization step is a step in which a radical polymerizable group undergoes a radical polymerization reaction during and / or after the condensation step to obtain particles. The heat treatment step is a step of drying and firing the polymer particles produced in the polymerization step, preferably at a temperature of 800C or lower, more preferably at a temperature of 100 to 600C. The heat treatment step is, for example, 10% by volume.
It is preferable to perform the reaction in an atmosphere having the following oxygen concentration or under reduced pressure.

As the compound having a functional group capable of reacting with the photosensitive resin used for treating the solid fine particles, the compound having a group capable of reacting with the functional group present in the solid fine particles, and And a compound having a functional group capable of reacting with the photosensitive resin and capable of coating at least a part of the surface of the solid fine particles. Examples of the compound having a group capable of reacting with the functional group present in the solid fine particles and having a functional group capable of reacting with the photosensitive resin include a double bond group, a carboxyl group, an amino group, an SH group, and an epoxy group. Silane-based coupling agents, titanate-based coupling agents, and aluminate-based coupling agents having at least one group selected from an isocyanate group and a hydroxyl group, and specifically, (meth) acryloxypropyl trialkoxy. Silane, (meth) acryloxypropylmethyl dialkoxysilane, γ-aminopropyl trialkoxysilane, γ-mercaptopropyl trialkoxysilane, vinyl trialkoxysilane, γ- (2-aminoethyl)
Examples include aminopropyl trialkoxysilane, γ-glycidoxypropyl trialkoxysilane, γ-glycidoxypropylmethyl dialkoxysilane, γ-isocyanatopropyl trialkoxysilane, γ-hydroxypropyl trialkoxysilane, and the like.

Examples of the compound having a functional group capable of reacting with the photosensitive resin capable of coating at least a part of the surface of the solid fine particles include, for example, a double bond group, a carboxyl group, an amino group, an SH group, Examples include polymers having at least one group selected from an epoxy group, an isocyanate group, and a hydroxyl group. The polymer may be non-crosslinked or crosslinked, and examples thereof include vinyl resins such as (meth) acrylic resins and styrene resins; epoxy resins; and polyester resins.

The amount of the compound having a functional group capable of reacting with the photosensitive resin is not particularly limited, but is preferably in the range of 0.01 to 100 wt%, more preferably 0.1 to 100 wt%, based on the solid fine particles. It is in the range of 1 to 30 wt%. The photoresist composition for forming a spacer of the present invention contains the above-described photosensitive resin, a component other than the solid fine particles having a functional group capable of reacting with the photosensitive resin, a solvent, a thickener, a leveling agent, and the like. There may be.

The photoresist composition for forming a spacer according to the present invention is for producing a spacer for a liquid crystal display device by photolithography. In a first liquid crystal display device of the present invention, liquid crystal is sealed between a pair of transparent substrates, and transparent electrodes are respectively provided on the transparent substrate surfaces opposed to each other with the liquid crystal interposed therebetween, and further, the liquid crystal layer Is provided with a spacer for keeping the thickness of the film constant. Further, a color filter is provided on one of the transparent substrates as needed. FIG. 1 is a schematic sectional view showing an example of such a liquid crystal display device.

FIG. 1 includes a pair of electrode substrates (a first electrode substrate 110 and a second electrode substrate 120) which are arranged to face each other with a liquid crystal material interposed therebetween, and a spacer. First electrode substrate 11
0 has a first transparent substrate 11 and an electrode 5 formed on the surface of the first transparent substrate 11. The second electrode substrate 120 is
A second transparent substrate 12, a color filter 23 including a black matrix 21 and red, green, and blue pixels 22 formed thereon, and a color filter 23 formed on the second transparent substrate 12 to fill in irregularities on the surface of the color filter. Insulating flattening film 24
And an electrode 5 further formed thereon, and an alignment film 25 further formed thereon. First electrode substrate 11
The first electrode substrate 120 and the second electrode substrate 120 are adhered to each other by a sealing material 2 at a peripheral portion thereof. The spacers are selectively dispersed between the substrates to maintain the distance between the substrates, and include a seal spacer (not shown) dispersed in the seal material 2 and an in-plane spacer dispersed in the plane. 8 exists.
The in-plane spacer 8 exists in such a manner as to partially protrude from the film 26 of the photoresist composition. The liquid crystal material 7 is sealed between the first electrode substrate 110 and the second electrode substrate 120,
First electrode substrate 110, second electrode substrate 120, and sealing material 2
The space enclosed by and is filled. Note that FIG. 1 shows a liquid crystal display device having a color filter. However, a color filter is not required if the device does not support color.

The first liquid crystal display device of the present invention uses the photoresist composition for forming a spacer of the present invention described above,
A film of the photoresist composition is left in a non-pixel region of a liquid crystal display device by a photolithography technique. Although the photoresist composition contains solid fine particles that function as spacers, since the thickness of the photoresist composition film is significantly reduced from the initial coating thickness, the solid fine particles partially protruded from the film. It becomes a shape and functions as a spacer. This is because if a spacer is present in the pixel region, the portion where the spacer is present is not displayed, and light leakage occurs around the spacer itself or around the spacer due to disorder in the alignment of the liquid crystal. Therefore, for example, in the case of the TN mode, it is preferable to dispose the spacer only in an area that is not directly related to the display, such as around a character or a design or a gap. Further, for example, in the case of the STN mode, since the transparent electrodes of the electrode substrate are arranged in a stripe shape, it is preferable to dispose a spacer between the transparent electrodes. Further, for example, in the case of color display of a TFT or STN, it is preferable to dispose the color filter pixels on portions other than R, G, and B, that is, on a black matrix. In the case where the spacer is arranged on the electrode substrate facing the substrate having the color filter, it is preferable to arrange the spacer at a position corresponding to the black matrix.

In the first method of manufacturing a liquid crystal display device of the present invention, a film of the photoresist composition is formed in a non-pixel region of the liquid crystal display device by using the above-described photoresist composition for forming a spacer of the present invention. Exposure and development are performed by photolithography technology so that remains. Specifically, the following method is exemplified, but the method is not limited thereto. That is, a color filter including a black matrix and each pixel, a planarizing film,
After forming a transparent electrode and an alignment film according to a conventional method, the photoresist composition is applied on the entire surface of the alignment film to form a film of the photoresist composition. The film of the photoresist composition is exposed to ultraviolet light through a photomask having a desired pattern, and is exposed to light, unnecessary portions are removed by development, and post-baking is performed as necessary.

The dry film thickness of the photoresist composition film is not particularly limited as long as it is smaller than the diameter of the solid fine particles, but is preferably 0.1 to 2 μm, more preferably 0.2 to 1 μm.
More preferably, it is μm. If the dry film thickness is smaller than the above range, the fixing of the spacer is weak, and the spacer may move due to vibration or impact. If the dry film thickness is larger than the above range, the solid fine particles will be buried in the photosensitive resin layer and will not function as a spacer.

When the photosensitive resin contained in the photoresist composition is of a negative type, the exposed portions are cured and the unexposed portions are removed by development, so that the portions to be left exposed are exposed. Is used. On the other hand, when the photosensitive resin contained in the photoresist composition is a positive type, a photomask having a pattern such that the portion to be removed is exposed is used to remove the exposed portion by development.

In the first liquid crystal display device of the present invention, other than the spacers, for the electrode substrate, the sealing material, the liquid crystal material, and the like, those similar to the conventional one can be used similarly. As the electrode substrate, a glass substrate, a film substrate, or the like can be used. As the sealing material, an epoxy resin adhesive sealing material or the like is used. As the liquid crystal, a conventionally used liquid crystal may be used, for example, a biphenyl-based liquid crystal,
Phenylcyclohexane, Schiff base, azo, azoxy, benzoate, terphenyl, cyclohexylcarboxylate, biphenylcyclohexane, pyrimidine, dioxane, cyclohexylcyclohexaneester, cyclohexylethane, cyclohexene And fluorine-based liquid crystals can be used.

In the first liquid crystal display device of the present invention, for example, after the spacer is formed as described above, the one obtained by dispersing the sealing portion spacer in an adhesive sealing material such as epoxy resin is used for the other electrode substrate. The adhesive seal is placed on the adhesive seal by means of screen printing or the like, and a suitable pressure is applied. The adhesive is heated at a temperature of 100 to 180 ° C. for 1 to 60 minutes, or irradiated with an ultraviolet ray having an irradiation amount of 40 to 300 mJ / cm ^2. After the adhesive sealant is cured by heating, it can be manufactured by injecting liquid crystal and sealing the injection portion, but is not limited thereto.

The first liquid crystal display device of the present invention has the same applications as conventional liquid crystal display devices, for example, televisions, monitors,
It is used as an image display element of a personal computer, word processor, car navigation system, DVD, digital video camera, PHS (Personal Digital Assistant), and the like. [When using the composition for black matrix of (2)]
The composition for black matrix of (2), a photosensitive resin,
It includes a light-shielding substance and solid fine particles having a functional group capable of reacting with the photosensitive resin.

As the photosensitive resin, the same resin as the photosensitive resin contained in the photoresist composition for forming a spacer (1) can be used, but a light-shielding substance absorbs ultraviolet rays necessary for photopolymerization. For this reason, it is preferable to use a photosensitive resin having high sensitivity. As a light-shielding substance,
Carbon black, carbon black graft polymer, black organic pigment, titanium black, iron black, chromium black and the like can be used. Among them, a carbon black graft polymer obtained by grafting a polymer to carbon black is preferable in that it has excellent dispersibility in a photosensitive resin, and reacts with the photosensitive resin in that a strong black matrix is obtained by chemically bonding with the photosensitive resin. The carbon black graft polymer in which the polymer having a possible functional group is graphed is more preferable, and the carbon black graft polymer in which the polymer having a double bond group is grafted is most preferable. The amount used is 10 to 9 with respect to the photosensitive resin.
The proportion is preferably 0% by weight, more preferably 20 to 70% by weight.

The solid fine particles having a functional group capable of reacting with the photosensitive resin include the same solid fine particles having a functional group capable of reacting with the photosensitive resin contained in the photoresist composition for forming a spacer (1). Can be used. The composition for a black matrix of the present invention contains a solvent, a thickener, a leveling agent, and the like as components other than the above-described photosensitive resin, a light-shielding substance, and solid fine particles having a functional group capable of reacting with the photosensitive resin. It may be something.

The black matrix composition of the present invention comprises:
This is for producing a black matrix of a liquid crystal display device by a photolithography technique. Second embodiment of the present invention
In the liquid crystal display device, liquid crystal is sealed between a pair of transparent substrates, and transparent electrodes are respectively provided on the transparent substrate surfaces opposed to each other with the liquid crystal interposed therebetween, and further, the thickness of the liquid crystal layer is kept constant. It is provided with a spacer for holding. Further, a color filter is provided on one of the transparent substrates as needed. FIG. 2 is a schematic sectional view showing an example of such a liquid crystal display device.

In FIG. 2, a pair of electrode substrates (a first electrode substrate 110 and a second electrode substrate 120) disposed opposite each other with a liquid crystal material interposed therebetween, and a spacer are provided. First electrode substrate 11
0 has a first transparent substrate 11 and an electrode 5 formed on the surface of the first transparent substrate 11. The second electrode substrate 120 is
A second transparent substrate 12, a color filter 23 including a black matrix 21 and red, green, and blue pixels 22 formed thereon, and a color filter 23 formed on the second transparent substrate 12 to fill in irregularities on the surface of the color filter. Insulating flattening film 24
And an electrode 5 further formed thereon, and an alignment film 25 further formed thereon. First electrode substrate 11
The first electrode substrate 120 and the second electrode substrate 120 are adhered to each other by a sealing material 2 at a peripheral portion thereof. The spacers are selectively dispersed between the substrates to maintain the distance between the substrates, and include a seal spacer (not shown) dispersed in the seal material 2 and an in-plane spacer dispersed in the plane. 8 exists.
The in-plane spacer 8 exists so as to partially protrude from the black matrix. The liquid crystal material 7 is sealed between the first electrode substrate 110 and the second electrode substrate 120, and is filled in a space surrounded by the first electrode substrate 110, the second electrode substrate 120, and the sealing material 2. I have.

In the second liquid crystal display device of the present invention, a black matrix of a color filter of the liquid crystal display device is formed by photolithography using the above-described black matrix composition. Although the black matrix composition contains solid fine particles that function as spacers, the thickness of the film of the black matrix composition is significantly reduced from the initial coating film thickness, and thus the solid fine particles are partially removed from the film. It has a protruding shape and functions as a spacer. Since the black matrix is a non-pixel region, the spacer is arranged only in the non-pixel region. Therefore, light leakage around the spacer itself or around the spacer due to disturbance of the alignment of the liquid crystal does not occur.

As a second method of manufacturing a liquid crystal display device of the present invention, the above-described black matrix composition of the present invention is exposed and developed by photolithography to obtain a color liquid crystal display device. The black matrix of the filter is formed. Specifically, the following method is exemplified, but the method is not limited thereto. That is, after forming each pixel on a transparent substrate, the above-mentioned composition for a black matrix is applied over the entire surface to form a film of the composition. The film of the composition is exposed to ultraviolet light through a photomask of a desired pattern and exposed to light, unnecessary portions are removed by development, post-baking is performed as necessary, and each pixel and the black matrix are removed. To obtain a color filter. After that, a flattening film, a transparent electrode, and an alignment film are formed according to a conventional method. At this time, it is necessary to take care that the solid fine particles acting as spacers included in the composition for black matrix project above the alignment film, and that the transparent electrode does not exist where the solid fine particles exist. . This is because the presence of the transparent electrode on the solid fine particles causes a short circuit between the upper and lower substrates.

The dry thickness of the film of the composition for black matrix is not particularly limited as long as it is smaller than the diameter of the solid fine particles, but is preferably 0.1 to 2 μm, more preferably 0.2 to 2 μm.
More preferably, it is 1 μm. If the dry film thickness is smaller than the above range, the fixing of the spacer is weak, and the spacer may move due to vibration or impact. If the dry film thickness is larger than the above range, the solid fine particles will be buried in the photosensitive resin layer and will not function as a spacer.

When the photosensitive resin contained in the black matrix composition is a negative type, the exposed portion is cured and the unexposed portion is removed by development, so that the portion to be left exposed is exposed. A photomask having a pattern is used. On the other hand, when the photosensitive resin contained in the black matrix composition is a positive type, a photomask having a pattern that exposes a portion to be removed is used in order to remove an exposed portion by development.

In the second liquid crystal display device of the present invention, other than the spacers, for the electrode substrate, the sealing material, the liquid crystal material, and the like, those similar to the conventional one can be used similarly. As the electrode substrate, a glass substrate, a film substrate, or the like can be used. As the sealing material, an epoxy resin adhesive sealing material or the like is used. As the liquid crystal, a conventionally used liquid crystal may be used, for example, a biphenyl-based liquid crystal,
Phenylcyclohexane, Schiff base, azo, azoxy, benzoate, terphenyl, cyclohexylcarboxylate, biphenylcyclohexane, pyrimidine, dioxane, cyclohexylcyclohexaneester, cyclohexylethane, cyclohexene And fluorine-based liquid crystals can be used.

According to the second liquid crystal display device of the present invention, for example, after forming a spacer as described above, a sealing portion spacer dispersed in an adhesive sealing material such as epoxy resin is used as the other electrode substrate. The adhesive seal is placed on the adhesive seal by means of screen printing or the like, and a suitable pressure is applied. The adhesive is heated at a temperature of 100 to 180 ° C. for 1 to 60 minutes, or irradiated with an ultraviolet ray having an irradiation amount of 40 to 300 mJ / cm ^2. After the adhesive sealant is cured by heating, it can be manufactured by injecting liquid crystal and sealing the injection portion, but is not limited thereto.

The second liquid crystal display device of the present invention has the same application as a conventional liquid crystal display device, for example, a television, a monitor,
It is used as an image display element of a personal computer, word processor, car navigation system, DVD, digital video camera, PHS (Personal Digital Assistant), and the like.

[0053]

The present invention will be described in more detail with reference to the following Examples, but it should not be construed that the invention is limited thereto. In the following, “parts” are used unless otherwise specified.
It shall represent "parts by weight". <Average particle diameter of solid fine particles, variation coefficient of particle diameter> Observing the solid fine particles with an electron microscope, actually measuring the particle diameter of 200 arbitrary particles in the photographed image, and calculating the average particle diameter and particle diameter according to the following formulas And the coefficient of variation of the particle diameter were determined.

[0054]

(Equation 1)

[0055]

(Equation 2)

[0056]

(Equation 3)

(Synthesis Example of Solid Fine Particles) [Synthesis Example 1] A monomer mixture composed of 80% by weight of divinylbenzene and 20% by weight of dipentaerythritol hexaacrylate was subjected to suspension polymerization. After separating the produced polymer particles from the slurry by decantation and washing with water,
By classification, spherical comparative solid fine particles (11) were obtained.

The obtained comparative solid fine particles (11) had an average particle diameter of 5.8 μm and a coefficient of variation in particle diameter of 4.0%. Next, a method for introducing a double bond group on the surface of the comparative solid fine particle (11) will be described below. First, 50 g of water, 50 g of isopropyl alcohol, and 10 g of γ-acryloxypropyltrimethoxysilane were mixed, 0.1 g of acetic acid was added and mixed, and the mixture was heated and stirred at 50 ° C. for 1 hour.

After cooling, 11 g of the solution obtained above was collected and mixed with 89 g of isopropyl alcohol, 10 g of comparative solid fine particles (11) were added to the solution, and the mixture was ultrasonically dispersed and mixed. After stirring the obtained dispersion for 2 hours,
After evaporating the solvent using an evaporator, the solid was dried under reduced pressure at 50 ° C. for 2 hours to obtain solid fine particles (1) having a double bond group on the surface. [Synthesis Example 2] A monomer mixture composed of 50% by weight of styrene, 15% by weight of methyl methacrylate, and 35% by weight of γ-methacryloxypropyltrimethoxysilane was subjected to dispersion polymerization. Next, acetic acid was added to cause hydrolysis and condensation of the methoxysilyl group. The produced polymer particles were separated from the slurry by decantation, washed with water, classified, and dried at 200 ° C. under reduced pressure to obtain spherical comparative solid fine particles (12).

The obtained comparative solid fine particles (12) had an average particle size of 5.7 μm and a variation coefficient of the particle size of 3.8%. Next, a double bond group was introduced into the surface of the obtained comparative solid fine particles (12) in the same manner as in Example 1 to obtain solid fine particles (2) having a double bond group on the surface. (Examples and Comparative Examples Using Photoresist Composition for Forming Spacer) [Example 1] First, a black matrix film was formed entirely on a glass substrate, and then a predetermined position was determined at a predetermined position by a photolithography technique. Unnecessary portions were removed so that the black matrix film having the shape remained. A red pixel, a green pixel, and a blue pixel were formed at a position where the black matrix film was removed by using a similar photolithography technique, and a color filter was provided. Next, after forming an insulating flattening film on the color filter, a scanning electrode made of a transparent conductive film was formed thereon, and an alignment film was further formed thereon to obtain a color filter side electrode substrate.

Next, 10 parts of solid fine particles (1) were dispersed in a solution in which 10 parts of an epoxy acrylate oligomer, 10 parts of pentaerythritol hexaacrylate, and 68 parts of ethyl cellosolve acetate were mixed as a photosensitive resin, and then photopolymerization was started. 2 parts of hydroxycyclohexyl phenyl ketone were mixed and dissolved as an agent to prepare a negative type photoresist composition (1) for forming a spacer. Next, the photoresist composition (1) was spin-coated on the alignment film of the color filter-side electrode substrate to form a thin film of the photoresist composition, which was leveled and prebaked. Next, using a photomask having a pattern in which light is irradiated only on the black matrix, the photoresist film present at the position corresponding to the black matrix is irradiated with ultraviolet rays, exposed, and immersed in a developing solution. The uncured portion was dissolved and developed. Next, a post-baking process was performed to leave a photoresist film mixed with the solid fine particles (1) only at positions corresponding to the black matrix.

The color filter side electrode substrate and the TFT side electrode substrate manufactured as described above are attached to each other with a sealing material to assemble a liquid crystal cell, and fluorine-based TN liquid crystal is sealed therein and the sealing hole is sealed. And a 15-inch liquid crystal display device (1). When this liquid crystal display device (1) was driven, since the spacers (solid fine particles (1)) were present only in the positions (non-pixel regions) corresponding to the black matrix, the contrast was high, and there was no display roughness. It had high display quality.

Next, the liquid crystal display device (1) is moved to X, Y, Z
A vibration test was performed by vibrating in the direction of 2 G at an acceleration of 2 G for 1 hour, and the contrast and the roughness of the display were the same as before the vibration test, and the high display quality was maintained. Comparative Example 1 Example 1 was repeated except that the comparative solid fine particles (11) were used in place of the solid fine particles (1).
A comparative photoresist composition (11) was prepared in the same manner as described above, and a photoresist film containing the comparative solid fine particles (11) was left only at positions corresponding to the black matrix by photolithography using the comparative photoresist composition (11). A filter-side electrode substrate was manufactured.

Next, when a comparative liquid crystal display device (11) was produced in the same manner as in Example 1, before the vibration test, the contrast was high as in Example 1, and there was no display roughness, and high display quality was obtained. Had. However, when a vibration test similar to that of Example 1 was performed, a decrease in contrast and a feeling of display roughness occurred, and the display quality was deteriorated. [Example 2] A photoresist composition (2) was prepared and used in the same manner as in Example 1 except that solid fine particles (2) were used instead of solid fine particles (1). Then, a color filter-side electrode substrate having a photoresist film mixed with the solid fine particles (2) remaining only at positions corresponding to the black matrix was manufactured by photolithography.

Next, when a liquid crystal display device (2) was produced in the same manner as in Example 1, the contrast was high before and after the vibration test as in Example 1, and there was no feeling of display roughness. It had display quality. Comparative Example 2 Example 1 was repeated except that the comparative solid fine particles (12) were used in place of the solid fine particles (1).
A comparative photoresist composition (12) was prepared in the same manner as described above, and the photoresist film containing the comparative solid fine particles (12) was left only at the position corresponding to the black matrix by photolithography using the comparative photoresist composition (12). A filter-side electrode substrate was manufactured.

Next, when a comparative liquid crystal display device (12) was produced in the same manner as in Example 1, before the vibration test, the contrast was high as in Example 1, there was no feeling of display roughness, and high display quality was obtained. Had. However, when a vibration test similar to that of Example 1 was performed, a decrease in contrast and a feeling of display roughness occurred, and the display quality was deteriorated. When the panel after the vibration test was observed, no spacers (solid fine particles (1) and (2)) could be observed on the pixels in Examples 1 and 2, but the spacers (Comparative Examples 1 and 2) Solid fine particles (11) and (12)) were observed on the pixels.
That is, in Examples 1 and 2, the spacer did not move even when the panel was vibrated, whereas in Comparative Examples 1 and 2, the spacer moved to the pixel region. This is because, in Examples 1 and 2, a double bond group was present on the surface of the solid fine particles, and the solid fine particles were chemically bonded to the photosensitive resin and firmly fixed. It is considered that since no double bond group was present on the surface of the solid fine particles, there was no chemical bond with the photosensitive resin and the immobilization was weak, so that the particles were moved by vibration. (Examples and Comparative Examples Using Composition for Black Matrix) Example 3 30 parts of phenol novolak epoxy acrylate, 30 parts of bisphenol A-based polyfunctional epoxy acrylate, 10 parts of trimethylolpropane triacrylate as a photosensitive resin, light 5 parts of Irgacure 369 (manufactured by Ciba Geigy) as a polymerization initiator and 25 parts of ethyl cellosolve acetate as a solvent were mixed, and 20 parts of a carbon black graft polymer in which a polymer having a double bond group was grafted on carbon black was added and dispersed. Further, 5 parts of solid fine particles (1) were added and dispersed to obtain a composition for black matrix (1).

Next, the composition (1) for a black matrix is further applied by a spin coater on the substrate on which the red, green and blue pixels have been formed by photolithography.
Dried. Then, using a photomask having a pattern in which light is irradiated only on the black matrix to be produced, the obtained coating film is irradiated with ultraviolet rays on a photoresist film present at a position corresponding to the black matrix. After the exposure, the uncured portion was dissolved by a shower of a developing solution to perform development to obtain a color filter-side transparent substrate having a black matrix containing solid fine particles (1) acting as a spacer.

Next, after an insulating flattening film is formed on the color filter, a scanning electrode made of a transparent conductive film is formed thereon, and an orientation film is further formed thereon. did. However, no transparent conductive film was formed on the solid fine particles (1) acting as a spacer.
The color filter-side electrode substrate and the TFT-side electrode substrate manufactured as described above are attached to each other with a sealing material to assemble a liquid crystal cell. Fluorine-based TN liquid crystal is sealed therein, and the sealing hole is sealed. Liquid crystal display device (3)
I got

When this liquid crystal display device (3) was driven, the spacers (solid fine particles (1)) existed only at the positions (non-pixel regions) corresponding to the black matrix.
The display had high contrast, no display roughness, and high display quality. Next, the liquid crystal display device (3) is
By vibrating for 1 hour each at 2G acceleration in the Y and Z directions,
When the vibration test was performed, the contrast and the roughness of the display were the same as before the vibration test, and the high display quality was maintained. Comparative Example 3 Example 3 was repeated except that the comparative solid fine particles (11) were used instead of the solid fine particles (1).
In the same manner as described above, the composition for comparative black matrix (1
Comparative solid fine particles (11) which act as spacers by preparing 1) and using this by photolithography technology
The transparent substrate on the color filter side having a black matrix containing was obtained.

Next, when a comparative liquid crystal display device (13) was produced in the same manner as in Example 3, before the vibration test, the contrast was high as in Example 3, there was no display roughness, and high display quality was obtained. Had. However, when a vibration test similar to that in Example 3 was performed, the generation of non-displayed pixels, the occurrence of color unevenness, a decrease in contrast, and the appearance of display roughness occurred, and the display quality was significantly reduced. Example 4 A black matrix composition (2) was prepared in the same manner as in Example 3 except that the solid fine particles (2) were used instead of the solid fine particles (1).
Using this, a color filter-side transparent substrate having a black matrix containing solid fine particles (2) acting as a spacer was obtained by a photolithography technique.

Next, when a liquid crystal display device (4) was produced in the same manner as in Example 3, before and after the vibration test, the contrast was high as in Example 3, and there was no feeling of display roughness. It had display quality. Comparative Example 4 Example 3 was repeated except that the comparative solid fine particles (12) were used instead of the solid fine particles (1).
In the same manner as described above, the composition for comparative black matrix (1
2) is prepared and comparative solid fine particles (12) acting as spacers are prepared by photolithography using the same.
The transparent substrate on the color filter side having a black matrix containing was obtained.

Next, when a comparative liquid crystal display device (14) was produced in the same manner as in Example 3, before the vibration test, the contrast was high as in Example 3, and there was no display roughness, and high display quality was obtained. Had. However, when a vibration test similar to that in Example 3 was performed, the generation of non-displayed pixels, the occurrence of color unevenness, a decrease in contrast, and the appearance of display roughness occurred, and the display quality was significantly reduced.

When the panel after the vibration test was observed, the spacers (solid fine particles (1) and (2)) were obtained in Examples 3 and 4.
However, in Comparative Examples 3 and 4, spacers (comparative solid fine particles (11) and (12)) were observed on the pixels. That is, in Examples 3 and 4, the spacers did not move even when the panel was vibrated, whereas in Comparative Examples 3 and 4, the spacers moved to the pixel region, damaging the pixels, and causing gap unevenness. I understood. This is because, in Examples 3 and 4, since the double bond group was present on the surface of the solid fine particles, the solid fine particles were chemically bonded to the photosensitive resin and firmly fixed. Since there is no double bond group on the surface of the solid fine particles,
It is considered that they moved by vibration because there was no chemical bond with the photosensitive resin and the immobilization was weak.

[0074]

According to the present invention, a liquid crystal in which spacers composed of solid fine particles are accurately formed only in a non-pixel region by using a photolithography technique, and the spacers move little even when vibration or impact is applied. A display device can be provided. In particular, even when the substrate size is large (for example, 550 × 650 mm or more) or the panel size is large (for example, 14 inches or more),
Since the movement of the spacer is small, a liquid crystal display device with very high display quality can be provided.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view illustrating an example of a liquid crystal display device of the present invention.

FIG. 2 is a schematic sectional view illustrating another example of the liquid crystal display device of the present invention.

[Description of Signs] 2 sealant 4 alignment film 5 electrode 6 polarizing film 7 liquid crystal 8 in-plane spacer 11 lower glass substrate 12 upper glass substrate 21 black matrix 22 pixel 23 color filter 24 flattening film 25 alignment film 26 photoresist composition Object film 110 Lower electrode substrate 120 Upper electrode substrate

Continued on the front page (72) Inventor Shinji Wakatsuki 5-8, Nishiobari-cho, Suita-shi, Osaka Nippon Shokubai Co., Ltd. (72) Inventor Reinari Sasaki 5-8, Nishiobari-cho, Suita-shi, Osaka Nippon Shokubai Co., Ltd. (72) Inventor, Hayato Ikeda 5-8, Nishiobari-cho, Suita-shi, Osaka Nippon Shokubai Co., Ltd. (72) Inventor Tatsuto Matsuda 5-8, Nishi-Otabi-cho, Suita-shi, Osaka F-term, Nippon Shokubai Co., Ltd. (Ref.) FB14X FB146 FB15X FB156 FB16X FB166 FD20Y FD207 GP00 GP03

Claims (6)

[Claims] 1. A photoresist composition for forming a spacer, comprising a photosensitive resin and solid fine particles having a functional group capable of reacting with the photosensitive resin. 2. A liquid crystal is sealed between a pair of transparent substrates, and transparent electrodes are respectively provided on the transparent substrate surfaces opposed to each other with the liquid crystal interposed therebetween, and further, the thickness of the liquid crystal layer is kept constant. In a liquid crystal display device provided with a spacer for performing the above, the spacer is obtained by leaving a film of the photoresist composition in a non-pixel region by a photolithography technique using the photoresist composition according to claim 1. A liquid crystal display device, comprising: 3. A liquid crystal is sealed between a pair of transparent substrates, and transparent electrodes are respectively provided on the transparent substrate surfaces opposed to each other with the liquid crystal interposed therebetween, and further, the thickness of the liquid crystal layer is kept constant. In a method of manufacturing a liquid crystal display device provided with a spacer for performing a photolithography process, the photoresist composition according to claim 1 is used so that a film of the photoresist composition remains in a non-pixel region. A method for manufacturing a liquid crystal display device, comprising a step of performing exposure and development processing. 4. A composition for a black matrix of a color filter, comprising a photosensitive resin, a light-shielding substance, and solid fine particles having a functional group capable of reacting with the photosensitive resin. 5. A liquid crystal is sealed between a pair of transparent substrates, a color filter is provided on one of the transparent substrates, and transparent electrodes are respectively provided on the transparent substrate surfaces opposed to each other with the liquid crystal interposed therebetween. Provided in a liquid crystal display device further provided with a spacer for keeping the thickness of the liquid crystal layer constant, wherein the black matrix of the color filter is formed by photolithography using the composition according to claim 4. A liquid crystal display device characterized by being formed. 6. A method for producing a black matrix of a color filter, wherein the composition according to claim 4 is exposed and developed by a photolithography technique.