JP2009003330A - Black photosensitive resin composition, method for producing black matrix using the same, color filter, and liquid crystal display device - Google Patents

Abstract

An object of the present invention is to provide a black photosensitive resin composition for obtaining a black matrix excellent in pattern reproducibility, a method for producing a black matrix using the same, a color filter, and a liquid crystal display device.
A black photosensitive resin composition comprising at least a photopolymerizable monomer, a resin binder, a polymerization initiator, a black pigment, and a solvent,
A black photosensitive resin composition containing at least one selected from an acetophenone photopolymerization initiator, a sulfonium organic boron complex, and an oxosulfonium organic boron complex is applied on the transparent substrate 11 as the polymerization initiator, The black photosensitive layer 21 is formed, pattern exposure is performed using far ultraviolet rays having an exposure wavelength of 254 nm, and patterning processing such as development is performed to obtain a black matrix 21a having excellent pattern reproducibility.
[Selection] Figure 3

Description

  The present invention relates to a black photosensitive resin composition, a method for producing a black matrix using the same, a color filter, and a liquid crystal display device, and in particular, a black photosensitive resin composition excellent in pattern reproducibility and a black matrix using the same. About.

  As shown in FIG. 7, the color liquid crystal display device 400 generally encloses a liquid crystal 81 between the color filter substrate 300 and the array substrate 110, and has a polarizing film 91 on both sides and a backlight 120 on the back of the array substrate 110. A voltage is applied to each pixel between the transparent electrode 21 and the electrode on the array substrate 110 to control the transmission / non-transmission of light, and the transmitted light is displayed on the screen as display light.

  As shown in FIG. 6, the color filter substrate 300 has the black matrix 22, the transparent red pixel 34R, the transparent green pixel 35G, the transparent blue pixel 36B, the overcoat layer 42, and the transparent electrode 52 formed on the transparent substrate 11. Is.

Various methods are known for forming the black matrix 22 of the color filter substrate 300. One common method is to form a black photosensitive layer formed using a negative black photosensitive resin composition by proximity. A photolithographic process in which pattern exposure and development are performed by a proximity exposure method using an aligner is common.
Further, a colored photosensitive layer is formed with a colored photosensitive resin composition of each color on the transparent substrate 11 on which the black matrix 22 is formed, and the patterning process of the photolithographic process is sequentially repeated, so that the three-color transparent red pixels 34R, transparent A green pixel 35G and a transparent blue pixel 36B are formed to produce a color filter substrate.

  The liquid crystal display device includes a device that uses light of a light source such as a backlight 120 disposed on the back surface of the array substrate 110 as display light, and a device that reflects external light such as outdoor light and uses it as display light. Broadly divided. The former is called a transmissive liquid crystal display device, which can display a bright screen, but requires a built-in light source inside the device, and consumes a large amount of power. On the other hand, the latter is called a reflective liquid crystal display device, which consumes less power, but it is difficult to obtain a bright display screen indoors where there is little external light.

  Therefore, taking advantage of the advantages of the transmissive liquid crystal display device and the reflective liquid crystal display device, a bright screen display is performed using the light of the built-in light source as display light indoors, and outside light is utilized outdoors. A liquid crystal display device that prevents power consumption has been proposed, and such a device is called a transflective liquid crystal display device. Such transflective liquid crystal display devices have already been put into practical use as display devices for mobile devices such as mobile phones and digital still cameras.

  In recent years, the use of mobile devices has further expanded as information terminals and television viewing terminals, and these display devices are required to have higher resolution, higher luminance, and lower power consumption. With regard to the resolution in particular, for example, when a 2.4-inch type mobile phone having a conventional resolution of QVGA (320 × 240 pixels) becomes a resolution of VGA (640 × 480 pixels), a transparent red pixel The pixel widths of the 34R, the transparent green pixel 35G, and the transparent blue pixel 36B are narrowed from about 75 μm to about 25 μm. When the ratio of the line width of the black matrix 22 to the pixel width of the transparent red pixel 34R, the transparent green pixel 35G, and the transparent blue pixel 36B increases, the aperture ratio decreases and the display screen becomes dark. However, even when exposed by irradiating ultraviolet rays through a photomask that faithfully reproduces the pattern, diffracted light is generated from the edge of the light-shielding pattern of the photomask. Since the black photosensitive layer is exposed to a reduced resolution, the black matrix 22 is often used with a line width of about 6 μm.

In general, since the intensity of diffracted light is smaller than the intensity of transmitted light (0th order diffracted light), a method of accurately controlling the line width using this intensity difference is also conceivable. That is, in the exposure sensitivity curve obtained by plotting the common logarithm of the exposure amount with respect to the negative black photosensitive layer as the horizontal axis and the residual film ratio after development as the vertical axis, the larger the tangent tan θ of the rising angle θ, It is described that the contrast between the exposed area and the unexposed area after development is increased, and thus the resolution is improved (for example, see Non-Patent Document 1 and Non-Patent Document 2).
If this principle is used for exposure with the minimum necessary exposure amount, the negative black photosensitive layer is sensitive only to transmitted light (0th order diffracted light), and is sensitive to diffracted light having a lower intensity. do not do. If this is developed, it is possible to form the black matrix 22 having different remaining film ratios in the exposed portion and the non-exposed portion. Therefore, it is possible to accurately form a pattern with good resolution. Conceivable.

On the other hand, it is known that in the proximity exposure method using a proximity aligner, the resolution (R) is proportional to the square root of the product of the exposure wavelength (λ) and the exposure gap (D) (R∝√ (λ · D)). It is considered that the pattern can be accurately formed by narrowing the exposure gap. That is, by exposing the black photosensitive layer coated on the transparent substrate 11 and the photomask closer to the usual tens to hundreds of micrometers, the photomask pattern can be faithfully reproduced, and the thinned black It is considered that the matrix 21 can be formed accurately.
Latest Polymer Materials and Technology Overview ", 37 (1988) Ishikawa et al .: Tech Publishing Science Forum “Organic Electronics Materials”, 15 (1986) Taniguchi et al.

However, according to the study of the present inventor, it has been difficult to accurately form the black matrix 22 having a line width of 5 μm or less only by controlling the tan θ as described above.
In addition, since the method of narrowing the exposure gap leads to a decrease in yield such as mask breakage and common defects, it is considered that the limit is up to several tens of μm, and a black matrix with good resolution of 5 μm or less can be stably formed. It has the problem that it is difficult to obtain.

  The present invention has been devised in view of the above problems, and a black photosensitive resin composition for obtaining a black matrix excellent in pattern reproducibility (for example, a line width of 5 μm or less) and production of a black matrix using the same It is an object to provide a method, a color filter, and a liquid crystal display device.

In order to achieve the above object in the present invention, first, in claim 1, a black photosensitive material comprising at least a photopolymerizable monomer, a resin binder, a polymerization initiator, a black pigment, and a solvent. A functional resin composition comprising:
A black photosensitive resin composition characterized in that the polymerization initiator contains at least one selected from an acetophenone-based photopolymerization initiator, a sulfonium organic boron complex, and an oxosulfonium organic boron complex. .

  Moreover, in Claim 2, the said polymerization initiator contains at least 1 polymerization initiator whose maximum absorption wavelength is 330 nm or less, The black photosensitive resin composition of Claim 1 characterized by the above-mentioned. It is a thing.

  According to a third aspect of the present invention, a black photosensitive layer is formed on the transparent substrate using the black photosensitive resin composition according to the first or second aspect, and a black matrix is formed by performing patterning processes such as pattern exposure and development. This is a method for manufacturing a black matrix characterized by forming the black matrix.

  According to a fourth aspect of the present invention, in the method for producing a black matrix according to the third aspect, the exposure light used for the pattern exposure is far ultraviolet light having a wavelength of 254 nm.

  According to a fifth aspect of the present invention, the black matrix having a line width of 5 μm or less produced by the black matrix manufacturing method according to the third or fourth aspect and at least two or more transparent colored pixels are provided. Is a color filter.

  Furthermore, in Claim 6, it is set as a liquid crystal display device provided with the color filter of Claim 5.

Since a black photosensitive layer is formed using the black photosensitive resin composition of the present invention and pattern exposure is performed with far ultraviolet light having a wavelength of 254 nm, pattern formation can be performed without impairing the exposure sensitivity and the cross-sectional shape of the pattern, Even if a proper exposure gap is ensured by the proximity exposure method using a proximity aligner, the influence of diffracted light can be reduced. Therefore, a black matrix having a line width of 5 μm or less can be formed accurately and stably.
This has the effect that a high-resolution and high-definition color filter substrate and a liquid crystal display device can be manufactured.

Hereinafter, embodiments of the present invention will be described.
The invention according to claim 1 comprises a black photosensitive resin composition comprising at least a photopolymerizable monomer, a resin binder, a polymerization initiator, a black pigment, and a solvent. And a black photosensitive resin composition containing at least one selected from an acetophenone-based photopolymerization initiator, a sulfonium organic boron complex, and an oxosulfonium organic boron complex.
In addition, it is desirable to contain a polymerization inhibitor. Moreover, you may contain additives, such as a dispersing agent, a photosensitizer, and a chain transfer agent.

The invention according to claim 2 is that the polymerization initiator contains at least one polymerization initiator having a maximum absorption wavelength of 330 nm or less. This maximum absorption wavelength can be easily tested by measuring the spectral spectrum of the black photosensitive layer obtained by applying the black photosensitive resin composition to the substrate using a photometer such as an ultraviolet-visible spectrophotometer. Can be obtained.
Since the polymerization initiator contains at least one polymerization initiator having a maximum absorption wavelength of 330 nm or less, the polymerization initiator can be cured with light having a shorter wavelength than the conventional exposure bright line centering on 365 nm (hereinafter referred to as i-line). In addition, since it is possible to reduce curing due to diffracted light having a low intensity, it is possible to improve the resolution without narrowing the exposure gap. For this reason, a black matrix having a line width of 5 μm or less can be accurately formed.

Incidentally, by adding a polymerization inhibitor composed of hydroquinone or methoquinone, it is possible to control the above-mentioned γ (contrast) and the exposure amount at which the remaining film ratio after development becomes 0%.

Hereinafter, each component which comprises the black photosensitive resin composition of this invention is demonstrated.
(Photopolymerization monomer)
The photopolymerizable monomer is polymerized by exposure light at the time of pattern exposure, and changes the black photosensitive layer obtained by applying the black photosensitive resin composition to be insoluble in the developer. Generally, it is a monomer whose polymerization is induced by radicals.
As such a photopolymerizable monomer, a polyfunctional urethane acrylate obtained by reacting a (meth) acrylate having a hydroxyl group with a polyfunctional isocyanate can be used.

  Examples of the (meth) acrylate having a hydroxyl group include 2-hydroxyethyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, trimethylolpropane di (meth) acrylate, pentaerythritol tri (meth) acrylate, ditrimethylolpropane tri ( (Meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol ethylene oxide modified penta (meth) acrylate, dipentaerythritol propylene oxide modified penta (meth) acrylate, dipentaerythritol caprocalactone modified penta (meth) acrylate, Glycerol acrylate methacrylate, glycerol dimethacrylate, 2-hydroxy-3-acryloylpropyl methacrylate, epoxy Shi group-containing compound and the carboxy (meth) reaction product of acrylate, hydroxyl group-containing polyol polyacrylate, and the like.

  Examples of the polyfunctional isocyanate include tolylene diisocyanate, hexamethylene diisocyanate, diphenylmethylene diisocyanate, isophorone diisocyanate, and polyisocyanate.

In the black photosensitive resin composition of the present invention, the content of the photopolymerizable monomer is determined from the viewpoint of developability, tackiness after being applied on a substrate and dried, and stability of the composition. The total amount is preferably 20% by weight or less with respect to 100% by weight. Moreover, it is preferable that it is 1 weight% or more from a viewpoint of exposure sensitivity, the resolution of the pattern obtained, and solvent resistance.
[Resin binder]
The resin binder adheres and fixes an unexposed black photosensitive resin composition coating film to a transparent substrate, and dissolves in a developing solution during development. A non-photosensitive resin or a photosensitive resin may be used.

  At present, as the developer, an alkaline developer having a small influence on the environment is often used. For this reason, it is desirable to use an alkali-soluble resin as the resin binder. For example, it is a non-photosensitive resin having an acidic functional group such as a carboxyl group or a sulfone group. Examples of such non-photosensitive resins include acrylic resins, α-olefin- (anhydrous) maleic acid copolymers, styrene- (anhydrous) maleic acid copolymers, styrene-styrene sulfonic acid copolymers, and ethylene- (meth). An acrylic acid copolymer, an isobutylene- (anhydrous) maleic acid copolymer, etc. are mentioned. An acrylic resin, an α-olefin- (anhydrous) maleic acid copolymer, and a styrene-styrene sulfonic acid copolymer are preferable. Among these, acrylic resins are preferably used because of their high heat resistance and transparency. A resin having a weight average molecular weight of 1,000 to 500,000, preferably 5,000 to 100,000 can be preferably used.

In addition, as a photosensitive resin, a linear polymer having a reactive functional group is reacted with a (meth) acrylic compound having a substituent capable of reacting with the reactive functional group, cinnamic acid, etc. Examples thereof include a resin in which a double bond is introduced into the linear polymer. Further, a linear polymer having a substituent capable of reacting with the reactive functional group is reacted with a (meth) acrylic compound having a reactive functional group, cinnamic acid, etc. Resin introduced into the polymer. Examples of the reactive functional group include a hydroxyl group, a carboxyl group, and an amino group. Examples of the substituent capable of reacting with the reactive functional group include an isocyanate group, an aldehyde group, and an epoxy group.

In addition, a linear polymer containing an acid anhydride such as a styrene-maleic anhydride copolymer or an α-olefin-maleic anhydride copolymer is a (meth) acrylic compound having a hydroxyl group such as hydroxyalkyl (meth) acrylate. Those half-esterified with can be used as the photosensitive resin.
These photosensitive resins preferably have a weight average molecular weight of 5,000 to 100,000.
[Black pigment]
As the black pigment, various inorganic pigments can be used in addition to organic pigments such as azo, phthalocyanine, quinacridone, benzimidazolone, isoindolinone, dioxazine, indanthrene, and perinone. is there.
Further, when carbon black is used as the black pigment, it is preferable to use it dispersed in an average particle diameter of 1 μm or less, preferably 0.5 μm or less.

Although content of a black pigment is not specifically limited, About 50 to 150 weight% is preferable normally with respect to a photopolymerizable polymer.
Moreover, when using a black pigment, it is desirable to contain the dispersing agent for dispersing this pigment. As the dispersant, a surfactant, an intermediate of pigment, an intermediate of dye, Solsperse, or the like is used. Although the addition amount of a dispersing agent is not specifically limited, It is preferable to set it as 1 to 10 weight% with respect to 100 weight% of compounding quantities of a pigment.
(Polymerization initiator)
As the polymerization initiator, an acetophenone-based photopolymerization initiator, a sulfonium organic boron complex, or an oxosulfonium organic boron complex can be suitably used. Specific examples of the acetophenone photopolymerization initiator include diethoxyacetophenone, 4-t-butyl-dichloroacetophenone, 4-phenoxydichloroacetophenone, 1- (4-isopropylphenyl) -2-hydroxy-2-methylpropane-1 -One, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1-hydroxycyclohexyl phenyl ketone, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butane-1- ON, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropan-1-one, 1- [4- (2-hydroxyethoxy) -phenyl] -2-hydroxy-2-methyl- 1-propan-1-one and the like can be mentioned. The sulfonium organic boron complex or the oxosulfonium organic boron complex is represented by the following formula (1).

式（１）において、Ｒ₁は、ベンジル基、置換されたベンジル基、フェナシル基、置換されたフェナシル基、アリールオキシ基、置換されたアリールオキシ基、アルケニル基、置換されたアルケニル基から選ばれる基を表し、Ｒ₂およびＲ₃は、それぞれ独立に、Ｒ₁を構成できる基と同じ基か、またはアルキル基、置換されたアルキル基、アリール基、置換されたアリール基、アラルキル基、置換されたアラルキル基、アルキニル基、置換されたアルキニル基、脂環基、置換された脂環基、アルコキシ基、置換されたアルコキシ基、アルキルチオ基、置換されたアルキルチオ基、アミノ基、置換されたアミノ基、またはＲ₂とＲ₃が相互に結合した環状構造を表し、Ｒ₄は酸素原子または孤立電子対を表し、Ｒ₅、Ｒ₆、Ｒ₇およびＲ₈は、それぞれ独立に、アルキル基、置換されたアルキル基、アリール基、置換されたアリール基、アラルキル基、置換されたアラルキル基、アルキニル基、置換されたアルキニル基を表す（但し、Ｒ₅、Ｒ₆、Ｒ₇およびＲ₈の全てが、アリール基または置換されたアリール基となることはない。）］
また、本発明の黒色感光性樹脂組成物を用いて黒色感光層を形成し、パターン露光する際、露光波長に２００ｎｍから３００ｎｍの露光強度比が高い遠紫外線が好ましく用いら
れることから、前記重合開始剤の最大吸収波長も、露光波長に合わせて３３０ｎｍ以下であるものが露光感度が高く好適に用いられる。
最大吸収波長が３３０ｎｍ以下であるアセトフェノン系光重合開始剤の例としては、２−（４−メチルベンジル）−２−（ジメチルアミノ）−１−（４−モルフォリノフェニル）ブタン−１−オン、２−メチル−１−〔４−（メチルチオ）フェニル〕−２−モルフォリノプロパン−１−オンなどが、最大吸収波長が３３０ｎｍ以下であるスルホニウム有機ホウ素錯体またはオキソスルホニウム有機ホウ素錯体の例としては、ジメチル（２−オキソ−２−フェニルエチル）スルフォニウムブチルトリフェニルボレート、ジメチル（２−オキソ−２−（４−ジメチルアミノフェニル）−エチル）スルフォニウムブチルトリフェニルボレートなどが例示できる。

In the formula (1), R ₁ is selected from a benzyl group, a substituted benzyl group, a phenacyl group, a substituted phenacyl group, an aryloxy group, a substituted aryloxy group, an alkenyl group, and a substituted alkenyl group. R ₂ and R ₃ each independently represents the same group as that capable of constituting R ₁ , or an alkyl group, a substituted alkyl group, an aryl group, a substituted aryl group, an aralkyl group, a substituted group Aralkyl groups, alkynyl groups, substituted alkynyl groups, alicyclic groups, substituted alicyclic groups, alkoxy groups, substituted alkoxy groups, alkylthio groups, substituted alkylthio groups, amino groups, substituted amino groups , or R ₂ and R ₃ represent a cyclic structure bound to one another, R ₄ represents an oxygen atom or a lone pair of _{electrons, R 5, R 6, R} 7 and R _8, which To be independently an alkyl group, substituted alkyl group, aryl group, substituted aryl group, an aralkyl group, substituted aralkyl group, an alkynyl group, a substituted alkynyl group (provided that, R _5, R _6, R ₇ and R ₈ are not all aryl groups or substituted aryl groups.)]
In addition, when a black photosensitive layer is formed using the black photosensitive resin composition of the present invention and pattern exposure is performed, far-ultraviolet rays having a high exposure intensity ratio of 200 nm to 300 nm are preferably used as the exposure wavelength. The maximum absorption wavelength of the agent is preferably 330 nm or less in accordance with the exposure wavelength because of high exposure sensitivity.
Examples of acetophenone photopolymerization initiators having a maximum absorption wavelength of 330 nm or less include 2- (4-methylbenzyl) -2- (dimethylamino) -1- (4-morpholinophenyl) butan-1-one, Examples of sulfonium organoboron complexes or oxosulfonium organoboron complexes in which 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropan-1-one or the like has a maximum absorption wavelength of 330 nm or less are as follows: Examples thereof include dimethyl (2-oxo-2-phenylethyl) sulfonium butyl triphenyl borate and dimethyl (2-oxo-2- (4-dimethylaminophenyl) -ethyl) sulfonium butyl triphenyl borate.

  In addition to this acetophenone photopolymerization initiator, or a sulfonium organic boron complex or an oxosulfonium organic boron complex, other polymerization initiators can be used in combination. Examples of such polymerization initiators include oxime ester compounds, benzoin compounds, benzophenone compounds, thioxanthone compounds, triazine compounds, phosphine compounds, quinone compounds, carbazole compounds, imidazole compounds, and titanocene compounds. Compounds and the like.

  Examples of the oxime ester compound include 1,2-octanedione, 1- [4- (phenylthio)-, 2- (O-benzoyloxime)], O- (acetyl) -N- (1-phenyl-2). -Oxo-2- (4'-methoxy-naphthyl) ethylidene) hydroxylamine.

  Examples of benzoin compounds include benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, and benzyl dimethyl ketal.

  Examples of the benzophenone compounds include benzophenone, benzoylbenzoic acid, methyl benzoylbenzoate, 4-phenylbenzophenone, hydroxybenzophenone, acrylated benzophenone, 4-benzoyl-4'-methyldiphenyl sulfide, and the like.

  Examples of thioxanthone compounds include thioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone, isopropylthioxanthone, 2,4-diisopropylthioxanthone, and the like.

  Examples of triazine compounds include 2,4,6-trichloro-s-triazine, 2-phenyl-4,6-bis (trichloromethyl) -s-triazine, and 2- (p-methoxyphenyl) -4,6-bis. (Trichloromethyl) -s-triazine, 2- (p-tolyl) -4,6-bis (trichloromethyl) -s-triazine, 2-pienyl-4,6-bis (trichloromethyl) -s-triazine, 2 , 4-Bis (trichloromethyl) -6-styryl s-triazine, 2- (naphth-1-yl) -4,6-bis (trichloromethyl) -s-triazine, 2- (4-methoxy-naphth-1) -Yl) -4,6-bis (trichloromethyl) -s-triazine, 2,4-trichloromethyl- (piperonyl) -6-triazine, 2,4-trichloromethyl (4'-me Kishisuchiriru) -6-triazine and the like can exemplified.

  Examples of the phosphine compound include bis (2,4,6-trimethylbenzoyl) phenylphosphine oxide and 2,4,6-trimethylbenzoyldiphenylphosphine oxide.

  Examples of the quinone compound include 9,10-phenanthrenequinone, camphorquinone, and ethylanthraquinone.

  The amount of the polymerization initiator used is preferably 0.5 to 50% by weight, more preferably 3 to 30% by weight, based on the total solid content of the photosensitive coloring composition.

Moreover, it is preferable to add a photosensitizer in addition to the polymerization initiator to the black photosensitive resin composition of the present invention.
An example of the photosensitizer is an amine compound. For example, triethanolamine, methyldiethanolamine, triisopropanolamine, methyl 4-dimethylaminobenzoate, ethyl 4-dimethylaminobenzoate, isoamyl 4-dimethylaminobenzoate, 2-dimethylaminoethyl benzoate, 4-dimethylaminobenzoate 2-ethylhexyl acid, N, N-dimethylparatoluidine, 4,4′-bis (dimethylamino) benzophenone, 4,4′-bis (diethylamino) benzophenone, 4,4′-bis (ethylmethylamino) benzophenone, etc. is there.

  Also, α-acyloxime ester, acylphosphine oxide, methylphenylglyoxylate, benzyl, 9,10-phenanthrenequinone, camphorquinone, ethylanthraquinone, 4,4′-diethylisophthalophenone, 3,3 ', 4,4'-tetra (t-butylperoxycarbonyl) benzophenone or the like can also be used as a sensitizer.

  The amount of these sensitizers used is preferably 0.5 to 60% by weight, more preferably 3 to 40% by weight, based on the total amount of photopolymerization initiator and sensitizer.

  Moreover, a polymerization inhibitor can be added to the black photosensitive resin composition of the present invention. The addition is important in that the γ (contrast) and the exposure amount at which the post-development residual film ratio becomes 0 can be controlled according to the type and addition amount of the polymerization inhibitor.

As the polymerization inhibitor, hydroquinone, methoquinone and the like can be preferably used.
In addition to this, pyrogallol, tert-butylcatechol, cuprous chloride, 2,6-di-tert-butyl-p-cresol, and the like can also be used.

  The amount of the polymerization inhibitor used is preferably 0.001 to 0.050% by weight based on the total solid content of the photosensitive black composition. If it is 0.001% by weight or less, the effect of adding a polymerization inhibitor is insufficient, and if it exceeds 0.050% by weight, the sensitivity is lowered, which is an adverse effect.

Moreover, the black photosensitive resin composition of this invention can be made to contain the polyfunctional thiol which acts as a chain transfer agent.
The polyfunctional thiol may be a compound having two or more thiol groups. For example, hexanedithiol, decanedithiol, 1,4-butanediol bisthiopropionate, 1,4-butanediol bisthioglycolate, ethylene Glycol bisthioglycolate, ethylene glycol bisthiopropionate, trimethylolpropane tristhioglycolate, trimethylolpropane tristhiopropionate, trimethylolpropane tris (3-mercaptobutyrate), pentaerythritol tetrakisthioglycolate, Pentaerythritol tetrakisthiopropionate, trimercaptopropionic acid tris (2-hydroxyethyl) isocyanurate, 1,4-dimethylmercaptobenzene, 2,4,6-trimercap -s- triazine, 2- (N, N- dibutylamino) -4,6-dimercapto -s- triazine.

The amount of polyfunctional thiol used is preferably 0.1 to 30% by weight, more preferably 1 to 20% by weight, based on the total solid content of the black composition. If it is less than 0.1% by weight, the effect of adding a polyfunctional thiol is insufficient, and if it exceeds 30% by weight, the sensitivity is too high and the resolution is lowered.
〔solvent〕
The solvent has a function of uniformly dispersing the black composition while enabling uniform application on the transparent substrate. As the solvent, water, an organic solvent, or the like can be used. As organic solvents, cyclohexanone, ethyl cellosolve acetate, butyl cellosolve acetate, 1-methoxy-2-propyl acetate, diethylene glycol dimethyl ether, propylene glycol monomethyl ether acetate, ethylbenzene, ethylene glycol diethyl ether, xylene, ethyl cellosolve, methyl-n amyl ketone, propylene Examples include glycol monomethyl ether toluene, methyl ethyl ketone, ethyl acetate, methanol, ethanol, isopropyl alcohol, butanol, isobutyl ketone, and petroleum solvents.

Next, the adjustment method of the black photosensitive resin composition which produces a black photosensitive resin composition using the said photopolymerizable monomer, a resin binder, a pigment, a dispersing agent, a solvent, etc. is demonstrated.
The black photosensitive resin composition of the present invention can be prepared by any of the following methods (1) to (4).

  (1) A pigment composition prepared by mixing a pigment and a dispersant in advance is added to a solution obtained by dissolving a photopolymerizable monomer and / or resin binder in a solvent, and dispersed, and the remaining components are added.

  (2) A pigment and a dispersant are separately added and dispersed in a solution in which a photopolymerizable monomer and / or resin binder or both are dissolved in a solvent, and then the remaining components are added.

  (3) A pigment is dispersed in a solution in which a photopolymerizable monomer and / or resin binder or both are dissolved in a solvent, a pigment dispersant is added, and then the remaining components are added.

  (4) Prepare two types of solutions in which a photopolymerizable monomer and / or resin binder or both are dissolved in a solvent, disperse the pigment and the dispersant separately in advance, then mix them and add the remaining components . One of the pigment and the dispersant may be dispersed only in the solvent.

  Here, the pigment and the dispersant can be dispersed using various dispersing devices such as a three-roll mill, a two-roll mill, a sand mill, a kneader, a dissolver, a high speed mixer, a homomixer, and an attritor.

  In addition, when preparing a pigment composition by previously mixing a pigment and a dispersant, the powder pigment and the powder dispersant may be simply mixed, but (a) a kneader, a roll, an attritor, a super mill, etc. Mix mechanically with various pulverizers, (b) Disperse the pigment in the solvent, add a solution containing the dispersant, and adsorb the dispersant on the pigment surface. (C) Strong dissolving power such as sulfuric acid It is possible to employ a mixing method such as co-dissolving the pigment and the dispersant in the solvent having the solvent and then coprecipitation using a poor solvent such as water.

A black photosensitive resin composition is prepared using the photopolymerizable monomer, resin binder, polymerization initiator, pigment, dispersant, solvent, and the like. As the polymerization initiator, a cetophenone-based photopolymerization initiator, a sulfonium organic boron complex, and By containing at least one polymerization initiator having at least one selected from an oxosulfonium organoboron complex and having a maximum absorption wavelength of 330 nm or less, it can be cured with far ultraviolet light at 254 nm as an exposure wavelength for pattern exposure. In addition, since hardening due to diffracted light having low intensity can be reduced, the resolution can be improved without narrowing the exposure gap, and a black matrix having a line width of 5 μm or less can be accurately formed.

The black matrix production method of the present invention, in which a black photosensitive layer is formed using the black photosensitive resin composition and patterning treatment such as pattern exposure and development is performed to form a black matrix, will be described below.
3 (a) to 3 (b) show a black matrix of the present invention in which a black photosensitive layer is formed using the black photosensitive resin composition of the present invention, and a black matrix is formed by performing patterning processes such as pattern exposure and development. It is a schematic structure sectional view showing an example of a manufacturing method of a matrix.

First, a black photosensitive resin composition is applied on the transparent substrate 11 and preliminarily dried to form a black photosensitive layer 21 (see FIG. 3A).
Here, as the transparent substrate 11, a glass substrate is suitable, and a resin substrate such as polycarbonate, polymethyl methacrylate, polyethylene phthalate, or the like can also be used.
Further, as a coating method, a spray coating method, a spin coating method, a roll coating or the like can be used.

Next, the black photosensitive layer 21 is subjected to pattern exposure using a photomask, and patterning processing such as development is performed to form a black matrix 21a. The black matrix in which the black matrix 21a is formed at a predetermined position on the transparent substrate 11. The substrate 10 is manufactured (see FIG. 3B).
The pattern exposure is preferably a proximity exposure system using a proximity aligner.
Here, as the exposure light used for pattern exposure, far ultraviolet rays having an exposure wavelength of 254 nm are used. This exposure wavelength of 254 nm is an emission line of a high-pressure mercury lamp that is easy to manufacture and can be obtained at low cost.
By pattern exposure using far ultraviolet rays with an exposure wavelength of 254 nm, the influence of diffracted light can be reduced even if a proper exposure gap is secured by proximity exposure using a proximity aligner, so a black matrix with a line width of 5 μm or less is accurate. It is possible to form well.

  Prior to pattern exposure, a solution of a water-soluble resin or an alkaline water-soluble resin (for example, polyvinyl alcohol or water-soluble acrylic resin) may be applied on the black photosensitive layer 21. By applying these resins, inhibition of polymerization by oxygen in the atmosphere can be suppressed, and the sensitivity of the black photosensitive layer 21 can be improved.

  Moreover, as a developing solution used for a development process, alkaline developing solutions, such as aqueous alkali solution or an organic alkaline solution, can be used. Examples of the alkaline aqueous solution include sodium carbonate and caustic soda, and examples of the organic alkaline solution include dimethylbenzylamine and triethanolamine. Moreover, an antifoamer and surfactant can be added as needed.

Hereinafter, the color filter of the present invention in which transparent colored pixels such as transparent red pixels, transparent green pixels, and transparent blue pixels are formed using the black matrix substrate 10 in which the black matrix 21a is formed at a predetermined position on the transparent substrate 11 will be described. explain.
4 (a) to 4 (d) and FIGS. 5 (e) to 5 (g) show a transparent red pixel and a transparent green color using a black matrix substrate 10 having a black matrix 21a formed at a predetermined position on the transparent substrate 11. It is a schematic structure sectional view showing an example of a manufacturing method of a color filter substrate which formed transparent coloring pixels, such as a pixel and a transparent blue pixel, in order of a process.

First, on a black matrix substrate 10 having a black matrix 21a formed at a predetermined position on the transparent substrate 11, a red resist in which a red pigment (for example, a dianthraquinone pigment) is dispersed in an acrylic photosensitive resin is used as a spinner or the like. Then, a red photosensitive layer is formed, and a series of patterning processes such as pattern exposure and development are performed using a predetermined photomask to form a transparent red pixel 31R (see FIG. 4A).

  Next, a green resist in which a green pigment (for example, phthalocyanine green pigment) is dispersed in an acrylic photosensitive resin is applied on the transparent substrate 11 on which the black matrix 21a and the transparent red pixel 31R are formed, using a spinner or the like. A green photosensitive layer is formed, and a series of patterning processes such as pattern exposure and development are performed using a predetermined photomask to form transparent green pixels 32G (see FIG. 4B).

  Next, a blue resist in which a blue pigment (for example, phthalocyanine blue pigment) is dispersed in an acrylic photosensitive resin on the transparent substrate 11 on which the black matrix 21a, the transparent red pixel 31R, and the transparent green pixel 32G are formed is spinner or the like. A blue photosensitive layer is formed by coating, and a series of patterning processes such as pattern exposure and development are performed using a predetermined photomask to form a transparent blue pixel 33B (see FIG. 4C).

  Next, an acrylic resin solution is applied to the transparent substrate 11 on which the black matrix 21a, the transparent red pixel 31R, the transparent green pixel 32G, and the transparent blue pixel 33B are formed using a spinner or the like, and is cured by heating and overcoating. A coat layer 41 is formed (see FIG. 4D).

  Next, an indium tin oxide based alloy target is sputtered to form a transparent conductive film on the overcoat layer 41 to form a transparent electrode 51 (see FIG. 5E).

  Next, on the transparent electrode 51, an acrylic clear resist is applied using a spinner or the like to form a photosensitive layer, and a series of patterning processes such as pattern exposure and development are performed using a predetermined photomask, The alignment control protrusion 61 is formed by heat curing (see FIG. 5F).

Further, on the transparent substrate 11 on which the black matrix 21a, the transparent red pixel 31R, the transparent green pixel 32G, the transparent blue pixel 33B, the overcoat layer 41, the transparent electrode 51, and the alignment control protrusion 51 are formed, acrylic is used using a spinner or the like. A system clear resist is applied to form a photosensitive layer, and a series of patterning processes such as pattern exposure and development are performed using a predetermined photomask, followed by heat curing to form the spacer 71.
Through the above steps, the transparent red pixel 31R, the transparent green pixel 32G, the transparent blue pixel 33B, the overcoat layer 41, the transparent matrix are formed on the black matrix substrate 10 on which the black matrix 21a of 5 μm or less is formed at a predetermined position on the transparent substrate 11. A color filter substrate 100 on which the electrode 51, the alignment control protrusion 51, and the spacer 71 are formed can be obtained (see FIG. 5G).

  A liquid crystal 81 is sealed between the color filter substrate 100 and the array substrate 110, a polarizing film 91 is provided on both sides, and a backlight 120 is provided on the back surface of the array substrate 110, whereby the liquid crystal display device 200 of the present invention is obtained. (See FIG. 2).

  Hereinafter, the black photosensitive resin composition of the present invention and a method for producing a black matrix using the same will be described in detail in Examples.

First, the materials blended at the composition ratio shown below were mixed and stirred to prepare a black photosensitive resin composition (A) of the present invention (pigment concentration in solid content: 40 parts by weight).
Carbon black dispersion: EX-2806 (manufactured by Gokoku Dye) 25.69 parts by weight Resin: V259-ME (manufactured by Nippon Steel Chemical Co., Ltd.) (solid content 56.1 parts by weight) 6.74 parts by weight Monomer: DPHA (Nippon Kayaku) 1.18 parts by weight Solvent: 28.82 parts by weight of propylene glycol monomethyl ether acetate 35.98 parts by weight of ethyl-3-ethoxypropionate Leveling agent: BYK-330 (manufactured by BYK Chemie) 1.00 parts by weight polymerization Initiator: Irg 379 (maximum absorption wavelength: 322 nm) 0.59 parts by weight Here, the polymerization initiator: Irg 379 is an acetophenone series, and “2- (4-methylbenzyl) -2- (dimethylamino) -1- ( 4-morpholinophenyl) butan-1-one ".

  Next, the black photosensitive resin composition (A) is applied onto the transparent substrate 11 made of a glass substrate by a spin coating method, pre-baked at 70 ° C. for 15 minutes, and the photosensitive layer 21 having a thickness of 1.3 μm. (See FIG. 3A).

Next, using a proximity exposure machine that uses far ultraviolet rays (254 nm) as an exposure light source, pattern exposure of a fine line pattern of 4 μm, shower development using a 1.25% by mass sodium carbonate solution, washing with water, A black matrix 21a was formed by heat treatment at 230 ° C. for 20 minutes, and a black matrix substrate 10 (A) having the black matrix 21a formed on the transparent substrate 11 made of a glass substrate was produced (FIG. 3B). reference).
In pattern exposure, samples with different exposure amounts were prepared in advance, an exposure sensitivity curve was obtained, and the minimum exposure amount at which the remaining film rate was 80% or more was set as the appropriate exposure amount.

First, the materials blended at the composition ratio shown below were mixed and stirred to prepare the black photosensitive resin composition (B) of the present invention (pigment concentration in solid content: 40 parts by weight).
Carbon black dispersion: EX-2806 (manufactured by Gokoku Dye) 25.69 parts by weight Resin: V259-ME (manufactured by Nippon Steel Chemical Co., Ltd.) (solid content 56.1 parts by weight) 6.74 parts by weight Monomer: DPHA (Nippon Kayaku) 1.18 parts by weight Solvent: 28.82 parts by weight of propylene glycol monomethyl ether acetate 35.98 parts by weight of ethyl-3-ethoxypropionate Leveling agent: BYK-330 (manufactured by BYK Chemie) 1.00 parts by weight polymerization Initiator: Irg907 (maximum absorption wavelength: 307 nm) 0.59 parts by weight Here, the polymerization initiator: Irg907 is an acetophenone-based "2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropane" -1-one ".

  Next, the black photosensitive resin composition (B) is applied onto the transparent substrate 11 made of a glass substrate by a spin coating method, and prebaked at 70 ° C. for 15 minutes to obtain a photosensitive layer 21 having a thickness of 1.3 μm. (See FIG. 3A).

Next, using a proximity exposure machine that uses far ultraviolet rays (254 nm) as an exposure light source, pattern exposure of a fine line pattern of 4 μm, shower development using a 1.25% by mass sodium carbonate solution, washing with water, A black matrix 21a was formed by heat treatment at 230 ° C. for 20 minutes, and a black matrix substrate 10 (B) having the black matrix 21a formed on the transparent substrate 11 made of a glass substrate was produced (FIG. 3B). reference).
In pattern exposure, samples with different exposure amounts were prepared in advance, an exposure sensitivity curve was obtained, and the minimum exposure amount at which the remaining film rate was 80% or more was set as the appropriate exposure amount.

First, the materials blended at the composition ratio shown below were mixed and stirred to prepare the black photosensitive resin composition (C) of the present invention (pigment concentration in solid content: 40 parts by weight).
Carbon black dispersion: EX-2806 (manufactured by Gokoku Dye) 25.69 parts by weight Resin: V259-ME (manufactured by Nippon Steel Chemical Co., Ltd.) (solid content 56.1 parts by weight) 6.74 parts by weight Monomer: DPHA (Nippon Kayaku) 1.18 parts by weight Solvent: 28.82 parts by weight of propylene glycol monomethyl ether acetate 35.98 parts by weight of ethyl-3-ethoxypropionate Leveling agent: BYK-330 (manufactured by BYK Chemie) 1.00 parts by weight polymerization Initiator: TRG271 (Maximum absorption wavelength: 239 nm) 0.59 parts by weight Here, the polymerization initiator: TRG271 is a sulfonium organoboron complex system, “dimethyl (2-oxo-2-phenylethyl) sulfonium butyltriphenyl”. Borate ".

  Next, the black photosensitive resin composition (C) is applied onto the transparent substrate 11 made of a glass substrate by a spin coating method, and prebaked at 70 ° C. for 15 minutes to obtain a photosensitive layer 21 having a thickness of 1.3 μm. (See FIG. 3A).

Next, using a proximity exposure machine that uses far ultraviolet rays (254 nm) as an exposure light source, pattern exposure of a fine line pattern of 4 μm, shower development using a 1.25% by mass sodium carbonate solution, washing with water, A black matrix 21a was formed by heat treatment at 230 ° C. for 20 minutes, and a black matrix substrate 10 (C) having the black matrix 21a formed on the transparent substrate 11 made of a glass substrate was produced (FIG. 3B). reference).
In pattern exposure, samples with different exposure amounts were prepared in advance, an exposure sensitivity curve was obtained, and the minimum exposure amount at which the remaining film rate was 80% or more was set as the appropriate exposure amount.

Example 4 is a comparative example for comparison.
First, the materials blended at the composition ratio shown below were mixed and stirred to prepare a black photosensitive resin composition (D) of comparative example (pigment concentration in solid content: 40 parts by weight).
Carbon black dispersion: EX-2806 (manufactured by Gokoku Dye) 25.69 parts by weight Resin: V259-ME (manufactured by Nippon Steel Chemical Co., Ltd.) (solid content 56.1 parts by weight) 6.74 parts by weight Monomer: DPHA (Nippon Kayaku) 1.18 parts by weight Solvent: 28.82 parts by weight of propylene glycol monomethyl ether acetate 35.98 parts by weight of ethyl-3-ethoxypropionate Leveling agent: BYK-330 (manufactured by BYK Chemie) 1.00 parts by weight polymerization Initiator: TRG278 (maximum absorption wavelength: 357 nm) 0.59 parts by weight Here, the polymerization initiator: TRG278 is a sulfonium organoboron complex system, which is “dimethyl (2-oxo-2- (4-dimethylaminophenyl) -ethyl”. ) Sulfonium butyltriphenylborate ".

  Next, the black photosensitive resin composition (D) is applied onto the transparent substrate 11 made of a glass substrate by a spin coating method, pre-baked at 70 ° C. for 15 minutes, and the photosensitive layer 21 having a thickness of 1.3 μm. (See FIG. 3A).

Next, using a proximity exposure machine that uses far ultraviolet rays (254 nm) as an exposure light source, pattern exposure of a fine line pattern of 4 μm, shower development using a 1.25% by mass sodium carbonate solution, washing with water, A black matrix 21a was formed by heat treatment at 230 ° C. for 20 minutes, and a black matrix substrate 10 (D) in which the black matrix 21a was formed on the transparent substrate 11 made of a glass substrate was produced (FIG. 3B). reference).
In pattern exposure, samples with different exposure amounts were prepared in advance, an exposure sensitivity curve was obtained, and the minimum exposure amount at which the remaining film rate was 80% or more was set as the appropriate exposure amount.

The black matrix pattern reproducibility of the black matrix substrates 10 (A) to (D) obtained in Examples 1 to 4 was measured with an optical microscope, and the cross-sectional shape was evaluated with a scanning electron microscope (S
EM). The evaluation results are shown in Table 1.

表１からも分かるように、最大吸収波長が３３０ｎｍ以下の重合開始剤を配合して作製した黒色感光性樹脂組成物を用いた実施例１〜３のブラックマトリクスは、４μｍのブラックマトリクスが再現されており、パターン再現性、断面形状とも良好な結果が得られた。
これに対し、最大吸収波長が３３０ｎｍ以上（３５７ｎｍ）の重合開始剤を配合して作製した黒色感光性樹脂組成物を用いた実施例４（比較例）のブラックマトリクスは、４μｍのブラックマトリクスの線幅バラツキがあり、パターン再現性、断面形状とも良好な結果を得ることができなかった。

As can be seen from Table 1, the black matrix of Examples 1 to 3 using a black photosensitive resin composition prepared by blending a polymerization initiator having a maximum absorption wavelength of 330 nm or less was reproduced as a 4 μm black matrix. The pattern reproducibility and the cross-sectional shape were good.
In contrast, the black matrix of Example 4 (comparative example) using a black photosensitive resin composition prepared by blending a polymerization initiator having a maximum absorption wavelength of 330 nm or more (357 nm) was a 4 μm black matrix line. There were variations in width, and good results could not be obtained in both pattern reproducibility and cross-sectional shape.

1 is a schematic cross-sectional view showing an embodiment of a color filter of the present invention. 1 is a schematic cross-sectional view showing an embodiment of a liquid crystal display device of the present invention. (A)-(b) is typical structure sectional drawing which shows one Example of the manufacturing method of the black matrix using the black photosensitive resin composition of this invention in order of a process. (A)-(d) is typical structure sectional drawing which shows a part of process of the manufacturing method of the color filter produced using the black matrix substrate formed using the black photosensitive resin composition of this invention. . (E)-(g) is typical structure sectional drawing which shows a part of process of the manufacturing method of the color filter produced using the black matrix substrate formed using the black photosensitive resin composition of this invention. . It is a schematic cross-sectional view showing an example of a color filter. It is a schematic structure sectional view showing an example of a liquid crystal display.

Explanation of symbols

10 ... Black matrix substrate 11 ... Transparent substrate 21 ... Black photosensitive layer 21a, 22 ... Black matrix 31R, 34R ... Transparent red pixel 32G, 35G ... Transparent green pixel 33B, 36B ... Transparent blue pixel 41, 42 …… Overcoat layer 51, 52 …… Transparent electrode 61 …… Alignment protrusion 71 …… Spacer 81 …… Liquid crystal 91 …… Polarizing film 100, 300 …… Color filter substrate 111 …… Array substrate 120 …… Backlight 200 ... Liquid crystal display device 400 ... Color liquid crystal display device

Claims (6)

A black photosensitive resin composition comprising at least a photopolymerizable monomer, a resin binder, a polymerization initiator, a black pigment, and a solvent,
The black photosensitive resin composition, wherein the polymerization initiator contains at least one selected from an acetophenone photopolymerization initiator, a sulfonium organic boron complex, and an oxosulfonium organic boron complex.   2. The black photosensitive resin composition according to claim 1, wherein the polymerization initiator contains at least one polymerization initiator having a maximum absorption wavelength of 330 nm or less.   A black photosensitive layer is formed on the transparent substrate using the black photosensitive resin composition according to claim 1, and a black matrix is formed by performing patterning processing such as pattern exposure and development. Matrix manufacturing method.   4. The method for producing a black matrix according to claim 3, wherein the exposure light used for the pattern exposure is far ultraviolet light having a wavelength of 254 nm.   5. A color filter comprising a black matrix having a line width of 5 [mu] m or less produced by the black matrix production method according to claim 3 and at least two or more transparent colored pixels.   A liquid crystal display device comprising the color filter according to claim 5.

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