JP2005189561A - Photosensitive black composition, black matrix substrate using the same and color filter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a photosensitive black composition which retains such a sensitivity as to form a cured film while reducing a carbon black content and has a wide development margin, and to provide a black matrix having a very high light blocking effect and a good shape. <P>SOLUTION: The photosensitive black composition contains a carbon black of ≥pH 5 having ≤100 ml/100 g oil absorption of dibutyl phthalate, an ethylenically unsaturated compound and a photopolymerization initiator having a weight reduction rate of ≥30% under the conditions of 230°C and 30 min. A black matrix substrate with the black matrix formed from the photosensitive black composition is provided, and a color filter with filter segments of at least two colors other than black formed on the black matrix substrate is also provided. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a photosensitive black composition used for producing a black matrix of a color filter used in combination with a liquid crystal display device or a solid-state imaging device, a black matrix substrate and a color filter using the same.

In order to improve contrast, a lattice-like black pattern called a black matrix having a light shielding property is generally formed in a gap portion between the red, green, and blue filter segments of the color filter.
Usually, the black matrix is often formed of a metal thin film having a fine pattern on a transparent substrate. For example, a method of forming a fine pattern by a photolithography method after forming a thin film of a metal or the like by a vacuum film formation method such as a vapor deposition method or a sputtering method using a metal or a metal compound such as chromium, nickel, or aluminum Is common. More specifically, a photoresist is applied on a thin film of metal, etc., dried, irradiated with ultraviolet rays through a photomask, and developed to form a resist pattern, followed by an etching step and a resist stripping step, followed by a black matrix. Form.

However, the black matrix substrate manufactured by the above method has a problem that the manufacturing cost is very high due to the complexity of the process, and the cost of a color filter using the black matrix substrate is also high. In addition, since the surface of a metal thin film (for example, a chromium thin film) generally used for manufacturing a black matrix has high reflectance, a color filter having a black matrix made of a metal thin film is added to a transmissive liquid crystal display. When mounted, there is a problem that the display quality is remarkably lowered when strong external light is incident on the color filter.
On the other hand, a method of forming a black matrix using a photosensitive black composition in which a black pigment such as carbon black or a pigment made by mixing several kinds of pigments is dispersed has been recently developed.

The black matrix formed using the photosensitive black composition has low surface light reflectance, can shorten the manufacturing process, and can produce large color filters. There are many advantages over the black matrix formed using.
Among them, the black matrix exhibiting high light-shielding properties includes, for example, a binder resin, a compound having at least one ethylenically unsaturated double bond, a photopolymerization initiator, a pH of 4 or less, and a volatile content of 1 to 10% by weight. And a photosensitive black composition containing carbon black having an average particle diameter of 20 to 60 nm, a specific surface area of 25 to 200 m ² / g, and an oil absorption of dibutyl phthalate of 100 ml / 100 g or less.
JP 2000-292615 A

However, when the conventional photosensitive black composition is used, since carbon black is strongly acidic, there is a problem in developability at the time of alkali cleaning at the time of forming the black matrix, for example, there is a problem that the margin width becomes narrow.
In addition, when a black matrix is to be formed by a photolithography method using a photosensitive black composition, it is necessary to increase the film thickness in order to obtain a light shielding property comparable to that of a metal thin film such as chromium. As a result, when the black matrix is formed on the TFT substrate side, when the red, green, and blue pigment dispersion liquid is applied after the black matrix is formed, or when the black matrix is formed on the TFT substrate side during transfer using the transfer sheet, the liquid crystal is formed at the level difference of the matrix. There has been a problem that the orientation of the film is disturbed.

  Further, in order to reduce the film thickness and obtain a light shielding property comparable to that of a metal thin film, it is necessary to add more black pigment such as carbon black in the composition. However, as the content of the black pigment increases, However, it is difficult to uniformly disperse the pigment, and there is a problem in that the dispersion stability is lowered such as an increase in viscosity with time of the photosensitive black composition. In addition, as the light-shielding property increases, the sensitivity decreases remarkably, and it becomes difficult to obtain a cured coating film even after irradiation with active energy rays, and a larger amount of exposure is required to obtain a sufficient cured coating film. There was a problem in that the productivity was lowered and the black matrix shape was deteriorated.

The photosensitive black composition of the present invention has a pH of 5 or more, carbon black having an oil absorption of dibutyl phthalate of 100 ml / 100 g or less, an ethylenically unsaturated compound, and weight loss under conditions of 230 ° C. for 30 minutes. It contains a photopolymerization initiator having a rate of 30% or more. In the photosensitive black composition of the present invention, the volatile content of carbon black is preferably 1 to 3% by weight, and the photopolymerization initiator is 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl). -Preferably it is butanone-1.
The black matrix substrate of the present invention is characterized by comprising a black matrix formed from the above photosensitive black composition, and the optical density per 1 μm dry film thickness of the black matrix is 3.0 or more. Preferably there is.
Furthermore, the color filter of the present invention is characterized in that filter segments of at least two colors other than black are formed on the black matrix substrate.

  The photosensitive black composition of the present invention has a sensitivity that can form a cured coating film by suppressing the content of carbon black, and has a wide development margin, so by using the photosensitive black composition of the present invention, A black matrix having a very high light shielding property and a good shape can be formed.

First, the photosensitive black composition of the present invention will be described.
The photosensitive black composition of the present invention is a composition having a characteristic that the film density of the coating film is reduced in the post-baking heating process at a high temperature of 230 ° C. for 30 minutes, and the optical density is improved. An unsaturated compound and a photopolymerization initiator are included.
The carbon black contained in the photosensitive black composition is a black pigment having a light shielding property, having a pH of 5 or more and an oil absorption of dibutyl phthalate (hereinafter referred to as “DBP”) of 100 ml / 100 g or less. . The oil absorption amount of DBP of carbon black must be 100 ml / 100 g or less from the viewpoint of photocurability, and the smaller the better. On the other hand, if the pH of the carbon black is less than 5, the development time in the alkali washing step when forming the black matrix is shortened, the margin width is narrowed, and the productivity is lowered. The pH of the carbon black is preferably 6-9, which is less susceptible to those effects, and particularly preferably 7-8, which is less susceptible to those effects.

Commercially available carbon black having a pH of 5 or more and a DBP oil absorption of 100 ml / 100 g or less includes, for example, # 260, # 25, # 33, # 44, # 45, # 45L, manufactured by Mitsubishi Chemical Corporation. # 47, # 50, # 52, Degussa Printex 35, Printex 45, Printex 55, Printex 300, Printex 350, CABOT REGL 250R, Tokai Carbon Co., Ltd. # 7550SB / F, and the like. Carbon black may be used individually by 1 type, or 2 or more types may be mixed and used for it.
Moreover, it is preferable that the volatile matter of carbon black is 1-3 weight%. If the volatile content is outside this range, it will not contribute to the reduction of the coating film in the baking step, and the optical density of the black matrix will not be sufficiently high.

Further, the average primary particle size of carbon black is preferably 20 to 50 nm. Carbon black having an average primary particle size of less than 20 nm is difficult to disperse at a high concentration, and it is difficult to obtain a photosensitive black composition having good stability over time. This is because the shape of the matrix may be deteriorated.
The content of carbon black in the photosensitive black composition is preferably 50% by weight or less based on the solid content of the composition, and is 30 to 45% by weight from the viewpoint of a balance between high optical density and photocurability. More preferably, it is 31 to 40% by weight. When the content of carbon black is more than 50% by weight, it is difficult to obtain dispersion stability, resulting in a decrease in sensitivity, which may make it difficult to form a black matrix.

  The ethylenically unsaturated compound contained in the photosensitive black composition is a compound having one or more ethylenically unsaturated double bonds, and monomers, oligomers, and photosensitive resins can be used. Examples of the monomer include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, cyclohexyl (meth) acrylate, polyethylene glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, and pentaerythritol tris. (Meth) acrylate, dipentaerythritol hexa (meth) acrylate, etc. are mentioned. In addition, examples of the oligomer include epoxy (meth) acrylate, urethane (meth) acrylate, ester (meth) acrylate and the like, and examples of the photosensitive resin include polyester, polyurethane, epoxy resin, acrylic resin, and the like by a known method. And those having an unsaturated double bond introduced therein.

An ethylenically unsaturated compound is used individually by 1 type or in mixture of 2 or more types.
Further, the content of the ethylenically unsaturated compound in the photosensitive black composition is preferably 5 to less than 30% by weight based on the solid content of the composition, and 7 to 7 from the viewpoint of photocurability and developability. More preferably, it is 28 weight%, Most preferably, it is 10-25 weight%. When the content of the ethylenically unsaturated compound is more than 30% by weight, it is not preferable because the black matrix shape is poor, and when it is less than 5% by weight, the photocurability is insufficient, which is not preferable.

The photopolymerization initiator has a weight reduction rate of 30% or more under the condition of 230 ° C. for 30 minutes. The weight reduction rate of the photopolymerization initiator is calculated by the following formula.
Weight reduction rate (%) = [(weight of photopolymerization initiator before firing−weight of photopolymerization initiator after firing at 230 ° C. for 30 minutes) / (weight of photopolymerization initiator before firing)] × 100
Examples of the photopolymerization initiator having a weight loss rate of 30% or more at 230 ° C. for 30 minutes include 2-methyl-1 [(4-methylthio) phenyl] -2-morpholinopropanone-1, 2- Α-aminoketone photopolymerization initiators such as benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1, 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1-phenyl- Α-Hydroxyketone photopolymerization initiators such as propanone-1, benzoin photopolymerization initiators such as benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether and benzyldimethyl ketal, benzophenone, benzoylbenzoic acid, benzoylbenzoic acid Methyl, 4-phenylbenzophenone, hydroxybenzophenone, etc. Benzophenone photopolymerization initiators, acylphosphine oxide photopolymerization initiators such as 2,4,6-trimethylbenzoyldiphenylphosphine oxide, 1- [4- (2-hydroxyethoxy) phenyl] -2-hydroxy-2- And methyl-1-propanone-1.

Of these, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1 is preferred from the viewpoints of photocurability and weight loss upon heating.
The said photoinitiator is used individually by 1 type or in mixture of 2 or more types. Even if the photopolymerization initiator has a weight loss rate of less than 30% under the condition of 230 ° C. for 30 minutes, it is used in combination within the range of 5 to 50% by weight of the total amount of the photopolymerization initiator from the viewpoint of photocurability. It doesn't matter.
The content of the photopolymerization initiator in the photosensitive black composition is preferably 5 to 25% by weight based on the solid content of the composition, and is 7 from the viewpoint of film reduction rate of the cured coating film and photocurability. It is more preferably ˜23 wt%, particularly preferably 8 to 22 wt%. When the content of the photopolymerization initiator is more than 25% by weight, it is not preferable because the shape of the black matrix is poor, and when it is less than 5% by weight, the photocurability is insufficient.

  Moreover, you may make a photosensitive black composition contain a sensitizer. Examples of the sensitizer include α-acyloxy ester, methylphenylglyoxylate, benzyl, 9,10-phenanthrenequinone, camphorquinone, ethyl anthraquinone, 4,4′-diethylisophthalophenone, 3, Examples include thioxanthone series such as 3 ′, 4,4′-tetra (t-butylperoxycarbonyl) benzophenone, 4,4′-diethylaminobenzophenone, 2,4-diethylthioxanthone, 2-chlorothioxanthone, isopropylthioxanthone, and the like. The above sensitizers are used alone or in combination of two or more.

Further, the photosensitive black composition can contain an alkali-soluble resin in order to make the composition into an alkali development type. In addition, the photosensitive black composition may contain an alkali-soluble resin and a resin that does not have alkali solubility depending on the purpose such as imparting heat resistance or adhesion.
Examples of the alkali-soluble resin include (meth) acrylic acid copolymers, styrene-maleic anhydride copolymers, and polyester resins having a carboxyl group.

The alkali-soluble resin can be used in combination of two or more resins according to various purposes such as imparting heat resistance, solvent resistance, and chemical resistance of the coating film.
The content of the alkali-soluble resin is preferably 5 to 50% by weight, more preferably 8 to 45% by weight, based on the solid content of the photosensitive black composition. When the content of the alkali-soluble resin is less than 5% by weight, the alkali developability deteriorates, and when it exceeds 50% by weight, the photocuring property of the photosensitive black composition and the light shielding property when used for forming a black matrix are lowered. Therefore, it is not preferable.

Moreover, in order to disperse | distribute carbon black contained in a photosensitive black composition stably, you may use a well-known pigment derivative and a resin type dispersing agent. Among these, by using a pigment derivative, carbon black can be stably dispersed at a high concentration, and adhesion and sensitivity can be improved. The pigment derivative contained in the photosensitive black composition is preferably the one represented by the general formula (A).
Formula (A)

（式中、Ｑは有機色素残基、Ｘは直接結合、−CONH−Y₂−、−SO₂NH−Y₂−、または
−CH₂NHCOCH₂NH−Y₂−（但し、Y₂は置換基を有してもよいアルキレン基またはアリール基を表す。）、
Y₁は−NH−または−O−、Ｚは水酸基、アルコキシ基、下記一般式で示される置換基、またはnが1の場合には−NH−X−Q、

(Wherein Q is an organic dye residue, X is a direct bond, -CONH-Y _2- , -SO ₂ NH-Y _2- , or -CH ₂ NHCOCH ₂ NH-Y _2- (where Y ₂ is a substituent) An alkylene group or an aryl group which may have a group).
Y ₁ is —NH— or —O—, Z is a hydroxyl group, an alkoxy group, a substituent represented by the following general formula, or when n is 1, —NH—X—Q,

（式中、Y₃は−NH−または−O−）、
R₁およびR₂は、それぞれ独立に置換もしくは無置換のアルキル基、またはR₁とR₂とで形成される少なくとも窒素原子を含むヘテロ環、ｍは1から６の整数、nは１から４の整数を表す。）

(Wherein Y ₃ is —NH— or —O—),
R ₁ and R ₂ are each independently a substituted or unsubstituted alkyl group, or a heterocycle containing at least a nitrogen atom formed by R ₁ and R ₂ , m is an integer of 1 to 6, and n is 1 to 4 Represents an integer. )

Examples of the dye derivative represented by the general formula (A) include dye derivatives represented by the following general formulas (1) to (10).

  Examples of the organic dye constituting the dye derivative represented by the general formula (A) include phthalocyanine, quinacridone, quinacridonequinone, isoindolinone, quinophthalone, diketopyrrolopyrrole, perylene, perinone, Indigo, thioindigo, dioxazine, anthraquinone, pyranthrone, anthanthrone, flavanthrone, indanthrone, metal complex, etc. condensed polycyclic organic pigments, benzimidazolone, insoluble azo, condensation Other organic pigments or dyes such as azo-based and soluble azo-based are listed.

  The pigment derivative represented by the general formula (A) may be used alone or in combination of two or more. The content of the pigment derivative represented by the general formula (A) is preferably 0.1 to 30 parts by weight, and more preferably 0.5 to 20 parts by weight with respect to 100 parts by weight of carbon black. When the content of the pigment derivative is less than 0.1 parts by weight, the effect of dispersing the carbon black is not sufficiently exhibited. When the content is more than 30 parts by weight, the dispersion of the carbon black becomes unstable, which is not preferable.

  The photosensitive black composition may contain a solvent in order to sufficiently disperse carbon black and form a black matrix having a desired film thickness. Examples of the solvent include cyclohexanone, ethyl cellosolve acetate, butyl cellosolve acetate, 1-methoxy-2-propyl acetate, ethylbenzene, xylene, ethyl cellosolve, methyl-n amyl ketone, propylene glycol monomethyl ether, toluene, methyl ethyl ketone, ethyl acetate, methanol, ethanol , Isopropyl alcohol, butanol, isobutyl ketone, petroleum solvent and the like, and these are used alone or in combination.

A chain transfer agent, a surfactant, other additives, and the like may be added to the photosensitive black composition for the purpose of improving coatability, sensitivity, and adhesion.
The photosensitive black composition is composed of a carbon black, an ethylenically unsaturated compound, a photopolymerization initiator, a solvent, and, if necessary, a pigment derivative, an alkali-soluble resin, and other additives. It can be produced by dispersing using various dispersing devices such as sand mill, kneader, and attritor.
The photosensitive black composition is prepared by means of centrifugal separation, sintering filter, membrane filter, or the like, with coarse particles of 5 μm or more, preferably coarse particles of 1 μm or more, more preferably coarse particles of 0.5 μm or more and mixed dust. Is preferably removed.

Next, the black matrix substrate will be described.
The black matrix substrate of the present invention means that a photosensitive black composition is applied on a transparent substrate by a coating method such as spin coating, slit coating, roll coating, etc., and then activated energy from the composition coating surface side through a photomask. Irradiate the wire, soak in a solvent or alkaline developer, or spray the developer with a spray to remove unirradiated parts, that is, uncured parts, and develop to form a black matrix of the desired shape Created by. As the transparent substrate, glass plates such as soda lime glass, low alkali borosilicate glass and non-alkali alumino borosilicate glass, and resin plates such as polycarbonate, polymethyl methacrylate, and polyethylene terephthalate are used. In addition, a transparent electrode made of indium oxide, tin oxide, or the like may be formed on the surface of the glass plate or the resin plate in order to drive the liquid crystal after forming the panel.

The coating thickness of the photosensitive black composition is preferably in the range of 0.2 to 5 μm (when dried), and more preferably in the range of 0.5 to 2 μm, which makes it easy to balance coating properties and light shielding properties.
The optical density per 1 μm dry film thickness of the black matrix is preferably 3.0 or more, more preferably 3.3 or more, from the viewpoint of high light shielding properties. The higher the optical density, the better. However, when the active energy ray is ultraviolet light or visible light, it is difficult to obtain a cured coating film.

As the alkali developer, an aqueous solution such as sodium carbonate or sodium hydroxide is used, and an organic alkali such as dimethylbenzylamine or triethanolamine can also be used. Moreover, an antifoamer and surfactant can also be added to a developing solution.
In order to improve photocurability by active energy rays, after applying and drying the photosensitive black composition, water-soluble or alkali-soluble resin such as polyvinyl alcohol or water-soluble acrylic resin is applied and dried to inhibit polymerization inhibition by oxygen. After forming the film to prevent, an active energy ray can also be irradiated from the composition application surface side.

  As the active energy ray, an electron beam, ultraviolet rays, or visible light of 400 to 500 nm can be used. A thermionic emission gun, a field emission gun, or the like can be used as the electron beam source irradiated from the composition application surface side. For example, a high-pressure mercury lamp, an ultrahigh-pressure mercury lamp, a metal halide lamp, a gallium lamp, a xenon lamp, a carbon arc lamp, or the like can be used as a source (light source) of ultraviolet light and visible light of 400 to 500 nm. Specifically, since it is a point light source and the luminance is stable, an ultrahigh pressure mercury lamp or a xenon mercury lamp is often used. The active energy dose irradiated from the composition application surface side can be set in a timely range of 5 to 1000 mJ, but is preferably in the range of 10 to 300 mJ that is easy to manage in the process.

Finally, the color filter will be described.
In the color filter, filter segments of at least two colors other than black are formed on the black matrix substrate. The color of the filter segment is selected from about 2 to 6 colors from blue, green, red, cyan, yellow, magenta, orange, purple and the like. Filter segments having the same color system and different densities may be formed.
Filter segment formation on black matrix substrate includes gravure offset printing method, waterless offset printing method, silk screen printing method, photolithography method using solvent developing type or alkali developing type colored resist, colloidal particle electrophoresis Examples thereof include an electrodeposition method in which a coloring material is electrodeposited on a transparent conductive film, a transfer method in which a filter segment layer previously formed on the surface of a transfer base sheet is transferred onto a black matrix substrate, and the like.

Since the printing method can be patterned simply by repeating printing and drying, the color filter manufacturing method is low in cost and excellent in mass productivity. Furthermore, it is possible to print a fine pattern having high dimensional accuracy and smoothness by the development of printing technology. In the case of producing a color filter by a printing method, it is important to control the fluidity of the ink on the printing press, and the ink viscosity can be adjusted with a dispersant or extender pigment.
The photolithography method using a solvent development type or alkali development type color resist is a method in which a color resist is applied on a black matrix substrate by a spin coating, slit coating, roll coating or the like, followed by ultraviolet exposure through a photomask. This is a method for producing a color filter by repeating the same operation for other colors after forming a desired pattern by washing away an unexposed portion with a solvent or an alkali developer. This manufacturing method can manufacture a color filter with higher accuracy than the above printing method.

  The colored resist is a resist containing a colorant having a desired color instead of the carbon black contained in the photosensitive black composition in the present invention. As the colorant, various colorants having excellent resistance are used. However, it is preferable to use a pigment from the viewpoint of light resistance, heat resistance and solvent resistance, and an organic pigment is used because of its light absorption ability. It is particularly preferable to do this. Specific examples of typical pigments are indicated by color index (CI) numbers.

Examples of yellow colorants include Pigment Yellow 12, 13, 14, 20, 24, 83, 86, 93, 94, 109, 110, 117, 125, 137, 138, 139, 147, 148, 153, 154, and 166. , 173 and the like.
Examples of the orange colorant include Pigment Orange 13, 31, 36, 38, 40, 42, 43, 51, 55, 59, 61, 64, 65, and the like.
Examples of red and magenta colorants include Pigment Red 9, 97, 122, 123, 144, 149, 166, 168, 177, 190, 192, 215, 216, 224, 254, and 255.

Examples of purple colorants include Pigment Violet 19, 23, 29, 32, 33, 36, 37, 38, and the like.
Examples of blue and cyan colorants include Pigment Blue 15 (15, 15: 1, 15: 2, 15: 3, 15: 4, 15: 6, etc.), 21, 22, 60, 64, and the like.
Examples of the green colorant include Pigment Green 7, 10, 36, 47, and the like.
These colorants may be used in combination of two or more in order to obtain a desired color.

Hereinafter, the present invention will be specifically described based on examples. In the examples, “parts” and “%” represent “parts by weight” and “% by weight”, respectively.
[Preparation of acrylic resin solution]
Put 800 parts of cyclohexanone in a reaction vessel, heat to 100 ° C while injecting nitrogen gas into the vessel, and at the same temperature, 60.0 parts of methacrylic acid, 65.0 parts of butyl methacrylate, 65.0 parts of methyl methacrylate, 60.0 parts of styrene, and azo A mixture of 10.0 parts of bisisobutyronitrile was added dropwise over 1 hour, and further reacted at 100 ° C. for 3 hours. Then, 2.0 parts of azobisisobutyronitrile dissolved in 50 parts of cyclohexanone was added. The reaction was continued at 100 ° C. for 1 hour to synthesize a resin solution. After cooling to room temperature, sample approximately 2 g of the resin solution, heat and dry at 180 ° C. for 20 minutes to measure the nonvolatile content, and add cyclohexanone to the previously synthesized resin solution so that the nonvolatile content is 20%. An acrylic resin solution was prepared. The weight average molecular weight of the acrylic resin was 40000.

[Preparation of carbon black dispersions 1-6]
The following carbon black and dispersant or pigment derivative are uniformly mixed with 24 parts of the above acrylic resin solution and 40 parts of cyclohexanone, and dispersed in a sand mill for 5 hours using glass beads having a diameter of 1 mm. ~ 6 were prepared. Table 1 shows the physical property values of the carbon black used.
(Carbon black dispersion 1)
・ Carbon black (Degussa “Printex 55”) 9.3 parts ・ Dispersant (Zeneca “Solsperse 20000”) 2.0 parts (Carbon black dispersion 2)
・ Carbon black (CABOT “REGAL 250R”) 7.9 parts ・ Dye derivative (1) 0.4 parts

(Carbon black dispersion 3)
・ Carbon black (“# 7550SB / F” manufactured by Tokai Carbon Co., Ltd.) 7.7 parts ・ Dye derivative (2) 0.4 part (carbon black dispersion 4)
・ Carbon black (Mitsubishi Chemical Corporation “# 47”) 7.5 parts ・ Dye derivative (3) 0.5 part (carbon black dispersion 5)
-Carbon black (Degussa "Nipex160IQ") 9.3 parts Dispersant (Zeneca "Solsperse 20000") 2.0 parts (carbon black dispersion 6)
・ Carbon black (Degussa "Special Black550" 9.3 parts ・ Dispersant (Zeneca "Solsper 20000" 2.0 parts

[Example 1]
60 parts of carbon black dispersion 1, 4.3 parts of trimethylolpropane triacrylate (“NK ester ATMPT” manufactured by Shin-Nakamura Chemical Co., Ltd.), photopolymerization initiator 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) ) -Butanone-1 (“Irgacure 369” manufactured by Ciba Geigy) 2.0 parts, sensitizer (“EAB-F” manufactured by Hodogaya Chemical Co., Ltd.) 0.4 part, and 21.6 parts of cyclohexanone were stirred and mixed uniformly. A photosensitive black composition was prepared by filtration through a filter.
[Example 2]
A photosensitive black composition was prepared in the same manner as in Example 1 except that the carbon black dispersion 1 was changed to the carbon black dispersion 2.

[Example 3]
A photosensitive black composition was prepared in the same manner as in Example 1 except that the carbon black dispersion 1 was changed to the carbon black dispersion 3.
[Example 4]
A photosensitive black composition was prepared in the same manner as in Example 1 except that the carbon black dispersion 1 was changed to the carbon black dispersion 4.
[Comparative Example 1]
The photopolymerization initiator 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1 was changed to a triazine photopolymerization initiator (“Adeka Arcles PZ-408” manufactured by Asahi Denka Kogyo Co., Ltd.) A photosensitive black composition was prepared in the same manner as in Example 1 except that.

[Comparative Example 2]
The photopolymerization initiator 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1 was changed to a carbazole / phenone photopolymerization initiator (“N-1414” manufactured by Asahi Denka Kogyo Co., Ltd.). Except for the above, a photosensitive black composition was prepared in the same manner as in Example 1.
[Comparative Example 3]
A photosensitive black composition was prepared in the same manner as in Example 1 except that the carbon black dispersion 1 was changed to the carbon black dispersion 5.
[Comparative Example 4]
A photosensitive black composition was prepared in the same manner as in Example 1 except that the carbon black dispersion 1 was changed to the carbon black dispersion 6.

About the obtained photosensitive black composition, the film reduction rate, sensitivity, black matrix shape, optical density, and development margin were evaluated by the following methods. The obtained results are shown in Table 2. Table 3 shows the weight loss rate of the photopolymerization initiator used in Examples and Comparative Examples under heating conditions at 230 ° C. for 30 minutes.
[Membrane reduction rate]
Film reduction rate (%) = [film thickness after heating at 230 ° C. for 30 minutes / film thickness before heating at 230 ° C. for 30 minutes] × 100

[sensitivity]
The photosensitive black composition was applied to a 10 cm × 10 cm glass substrate by spin coating, and then dried at 70 ° C. for 15 minutes to form a coating film having a dry film thickness of 1 μm. Thereafter, ultraviolet rays were exposed to 200 mJ / cm ² through a photomask using an ultrahigh pressure mercury lamp. Subsequently, the unexposed portion was spray-developed using an aqueous sodium carbonate solution, washed with ion-exchanged water to remove the unexposed portion, the film thickness after development of the exposed portion was measured, and evaluated in three stages.
○: Film thickness ≧ 0.95μm
△; 0.90μm ≤ Film thickness <0.95μm
×: Film thickness <0.90μm
[Black matrix shape]
A black matrix substrate was prepared by the above method. The linearity of the black matrix shape formed in the exposed portion was observed with an optical microscope and evaluated in three stages.
○: Good linearity Δ: Partially good linearity ×: Poor linearity

[Optical density]
The photosensitive black composition was applied to a glass substrate by the above method and then heated at 230 ° C. for 30 minutes. The optical density of the photosensitive black composition coated substrate thus obtained was measured with a Macbeth densitometer (GRETAG D200-II) to determine the optical density at a film thickness of 1.0 μm.
[Development margin]
The photosensitive black composition was applied to a glass substrate by the above-described method, and was exposed to 200 mJ / cm ^{2 of} ultraviolet rays through a photomask using an ultrahigh pressure mercury lamp. Next, the unexposed area was spray-developed using an aqueous sodium carbonate solution, the development time was increased in increments of 5 seconds from the time when only the exposed area remained (just development), and the time width until the time when the exposed area disappeared was measured. .

Claims (6)

  Photopolymerization with a pH of 5 or more, carbon black with an oil absorption of dibutyl phthalate of 100 ml / 100 g or less, an ethylenically unsaturated compound, and a weight reduction rate of 30% or more at 230 ° C for 30 minutes A photosensitive black composition comprising an agent.   The photosensitive black composition according to claim 1, wherein the volatile content of carbon black is 1 to 3% by weight.   3. The photosensitive black composition according to claim 1, wherein the photopolymerization initiator is 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1.   A black matrix substrate comprising a black matrix formed from the photosensitive black composition according to any one of claims 1 to 3.   5. The black matrix substrate according to claim 4, wherein an optical density per 1 [mu] m of the dry thickness of the black matrix is 3.0 or more. 6. A color filter, wherein filter segments of at least two colors other than black are formed on the black matrix substrate according to claim 4 or 5.