JPH0926571A - Composition for liquid crystal panel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To increase coloring power and hiding power and to obtain excellent insulating property by dispersing carbon black particles covered with a resin in a dispersion medium. SOLUTION: This compsn. for a liquid crystal panel is prepared by dispersing carbon black particles coated with a resin in a dispersion medium. Since the carbon black particles coated with a resin is used for the compsn. for a liquid crystal panel, the obtd. compsn. does not have conductivity which a compsn. using only carbon black particles shows, but have excellent non-conductivity (insulating property) and high coloring power and hiding power due to the carbon black particles showing excellent physical properties as a black matrix. Moreover, since the carbon black particles coated with a resin is properly and uniformly dispersed in the comps. for a liquid crystal panel, such problems are hardly caused that the viscosity of the compsn. increases too much, and the strength of a film to be formed and its adhesion property to a base body largely decrease.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a composition for a liquid crystal panel. More specifically, a liquid crystal panel having a large coloring power and a high hiding power and an excellent insulating property, which can be suitably used for a filter for fine color separation of a liquid crystal panel, a black matrix in a thin film transistor side substrate of a liquid crystal panel, and the like. Composition.

[0002]

2. Description of the Related Art Conventionally, studies have been made on the use of compositions obtained by blending carbon black with various synthetic resins for filters such as liquid crystal displays.

For example, JP-A-4-63870 discloses a black photosensitive polymer composition containing a photosensitive polymer, a photopolymerization initiator and a black pigment component composed of carbon black and a coloring pigment other than carbon black. Has been done.

[0004] The black photosensitive polymer composition is excellent in photosensitivity, has sufficient film strength, and has a certain degree of good electrical properties, despite its film being black. That can be suitably used as a black matrix in a filter for use.

However, when a filter for fine color separation using a black matrix is provided in a thin film transistor (hereinafter referred to as TFT) liquid crystal display panel, the T
There is a problem that the aperture ratio of the FT liquid crystal display panel is low and the power consumption is large.

Therefore, in order to improve the aperture ratio of the TFT liquid crystal display panel and reduce the power consumption, there has been proposed a liquid crystal panel having a black matrix on the TFT side as shown in FIG.

The liquid crystal panel 1 shown in FIG. 6 includes a pair of glass substrates 2 and 3 with a liquid crystal material 4 interposed therebetween.
A plurality of pixel electrodes 5 are formed on the surface of the glass substrate 2 facing the glass substrate 3, and each pixel electrode 5 has a TF.
T6 is connected. In addition, on the surface of the glass substrate 2 facing the glass substrate 3, avoiding the pixel electrode 5 above,
A black matrix 7 is provided between the pixel electrodes 5 and on the TFT 6. On the surface of the glass substrate 3 facing the glass substrate 2, a plurality of red (R), green (G), and blue (B) color filters 8 are provided so as not to contact each other. A common electrode 9 is formed on the entire surface of the glass substrate 3 facing the glass substrate 2 so as to cover it.

As described above, in the liquid crystal panel 1 in which the black matrix 7 is provided on the TFT 6 side, the black matrix 7 is in direct contact with the pixel electrode 5 and the TFT 6, so that the black matrix 7 is required to have a high degree of insulation. To be done.

However, the black photosensitive polymer composition is used in the black matrix 7 used in the liquid crystal panel 1.
It cannot be used for the black matrix 7 because it does not have the high insulating property required for the black matrix 7.

Further, as a composition for a liquid crystal panel, a composition colored black with a coloring pigment other than carbon black has been studied. However, in order to sufficiently color black with a color pigment other than carbon black, the hiding power of such a color pigment is weak, and therefore the amount of the compound must be extremely increased, resulting in an increase in the viscosity of the composition. As a result, there is a problem that the handling becomes difficult, and the strength of the formed film and the adhesiveness to the substrate are significantly reduced.

As described above, the fact is that a composition having particularly large coloring power and hiding power, excellent insulating properties, and suitable for use in a liquid crystal panel such as a liquid crystal display has not yet been developed. The development of products has been awaited.

[0012]

SUMMARY OF THE INVENTION The present invention has been made in view of the above prior art, and an object of the present invention is to provide a composition for a liquid crystal panel which has a large coloring power and a high hiding power and is excellent in insulating properties. To do.

[0013]

The present invention relates to a composition for liquid crystal panels in which carbon black coated with a resin is dispersed in a dispersion medium.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION The composition for liquid crystal panel of the present invention comprises
As described above, the carbon black coated with the resin is dispersed in the dispersion medium.

Since carbon black coated with a resin is used in the composition for liquid crystal panel of the present invention, such a composition for liquid crystal panel is electrically conductive like a composition in which carbon black is simply used. It has excellent physical properties as a black matrix, that is, has no property, has excellent non-conductivity (insulation), and has a large coloring power and hiding power by carbon black.
Further, since the resin-coated carbon black is appropriately and uniformly dispersed in the liquid crystal panel composition, its viscosity increases too much, and the strength of the formed film and the adhesion to the substrate are significantly different. It is less likely to decrease.

The carbon black used in the present invention includes, for example, channel black, acetylene black and furnace black, which may be used alone or in combination of two or more kinds.

The average primary particle size of the carbon black is not particularly limited, but in view of dispersibility in the liquid crystal panel composition, it is usually about 0.005 to 0.2 μm, especially about 0.01 to 0.1 μm. Is preferred.

The specific surface area of the carbon black is not particularly limited, but when the carbon black is coated with a resin, the conductivity inherent in the carbon black is reduced and the insulating property is sufficiently imparted. The value measured by the BET method is usually 20 to 1500 m ²
/ G, preferably about 50 to 1400 m ² / g.

The resin coated on the carbon black may be any resin that does not dissolve in the dispersion medium described below, and may be a thermoplastic resin or a thermosetting resin.

Typical examples of the thermoplastic resin include polyvinyl chloride resins such as polyvinyl chloride, polyvinylidene chloride and vinyl chloride-vinyl acetate copolymers; polyvinyl acetate resins such as polyvinyl acetate; polystyrene. Polystyrene resin such as; Polyethylene, polypropylene, polyolefin resin such as ethylene-vinyl acetate copolymer; Polyamide resin such as nylon-6, nylon-6,6; polymethyl (meth) acrylate,
Acrylic resins such as silicone acrylic resins; polyester resins such as polyethylene terephthalate and polybutylene terephthalate; polycarbonates, cellulose resins, polyacetals, polyphenylene oxides,
Examples include a noryl resin, a polysulfone, a fluorine-based resin, a silicon-based resin, an ABS resin, polyphenylene sulfide, polyimide, polyimide amide, and polydiphenyl ether. These can be used alone or in combination of two or more. Among these, fluorine-based resins, silicon-based resins, silicone acrylic resins, polyimides, polyimide amides, polydiphenyl ethers and the like are particularly preferable in terms of excellent heat resistance.

Typical examples of the thermosetting resin include phenol resin, urea resin, melamine resin, xylene resin, diallyl phthalate resin, epoxy resin, urethane resin and benzoguanamine resin, which may be used alone or in combination. A mixture of two or more species can be used. Among them, phenol resin, xylene resin, epoxy resin and the like are particularly preferable because of their excellent heat resistance.

The method of preparing the carbon black coated with the resin is not particularly limited, but, for example, after adjusting the compounding amounts of the carbon black and the resin appropriately, the resin is mixed with a solvent such as cyclohexanone, toluene or xylene. A composition obtained by mixing and stirring a resin solution that is heated and dissolved by heating and a suspension in which carbon black and water are mixed to separate carbon black and water, then remove water and heat knead the mixture. Is molded into a sheet, pulverized and then dried; the resin solution and the suspension prepared in the same manner as above are mixed and stirred to granulate the carbon black and the resin, and the obtained granules are Method of separating and heating to remove residual solvent and water; carboxylic acid such as maleic acid and fumaric acid is dissolved in the above-exemplified solvent to prepare carbon black. Addition, the mixture was dried, after to give a carboxylic acid impregnated carbon black to remove the solvent, a method of dry blending by the addition of the resin to this;
A reactive group-containing monomer component constituting the resin to be coated and water are stirred at high speed to prepare a suspension, which is cooled after polymerization to obtain the reactive group-containing resin from the polymer suspension, and then the carbon is added thereto. A method in which black is added and kneaded, carbon black and a reactive group are reacted (carbon black is grafted), and cooling and pulverization are performed can be employed.

Thus, a resin-coated carbon black can be obtained. The coating amount of the resin with respect to the carbon black is such that carbon black can be sufficiently imparted to the obtained composition for a liquid crystal panel. 10
It is preferably 1 part by weight or more, especially 5 parts by weight or more with respect to 0 parts by weight, and in order to obtain a liquid crystal panel composition having sufficient hiding power, carbon black 1
100 parts by weight or less to 00 parts by weight, especially 60
The amount is preferably not more than parts by weight, and it is preferable to appropriately adjust the blending ratio of carbon black and resin so as to obtain such a coating amount.

The surface resistivity of the carbon black coated with the resin can be measured according to the method described in the production example described later.

When the composition for liquid crystal panel of the present invention is used, for example, for forming a black matrix in a liquid crystal panel such as a liquid crystal display, it is required to have excellent insulating properties. The surface resistivity of the film of the mixture of the resin-coated carbon black and the resin, which contains 80% by weight of the resin-coated carbon black, is about 10 ⁵ Ω / □ or more,
It is preferably about 10 ⁷ Ω / □ or more.

The surface resistivity (unit: Ω / □)
Is generally called simply surface resistance (unit: Ω).

The content of the carbon black coated with the resin in the composition for liquid crystal panel is such that the effect of imparting the coloring power and the hiding power by the carbon black coated with the resin is sufficiently exhibited. Is 2
It is preferable to adjust the content to be not less than 5% by weight, especially not less than 5% by weight, and to prevent the viscosity of the composition for liquid crystal panel from increasing too much and the handling property to deteriorate, and to form the composition for liquid crystal panel. Considering the strength of the coating and the adhesion to the substrate, it is preferable to adjust the content to 60% by weight or less, and especially 40% by weight or less.

In the present invention, the carbon black coated with the resin is uniformly dispersed in the dispersion medium.

Examples of the dispersion medium include cellosolve acetate, propylene glycol monomethyl ether acetate, 3-methoxybutyl acetate, methoxypropyl acetate, 2-methoxyethyl acetate and the like; 3-ethoxyethyl propionate, propylene. An organic solvent such as a hydrocarbon compound having an ether bond and an ester bond such as glycol monomethyl ether propionate, water and the like are preferably used.

The composition for a liquid crystal panel of the present invention is a composition in which carbon black coated with the above resin is dispersed in a dispersion medium. In addition to these, if necessary, for example, a dispersant or an organic pigment. May be contained.

The dispersant is preferably used in the composition for liquid crystal panels in order to further improve the dispersibility of the carbon black or the organic pigment coated with the resin.

The dispersant may be any that can be dissolved in the dispersion medium. Typical examples thereof include oil-based polyurethanes, polycarboxylic acid esters such as polyacrylates, unsaturated polyamides, polycarboxylic acids, and the like.
Polycarboxylic acid (partial) amine salt, polycarboxylic acid ammonium salt, polycarboxylic acid alkylamine salt, polysiloxane, long-chain polyaminoamide phosphate, hydroxyl group-containing polycarboxylic acid ester, modified products thereof, poly (lower alkylene) (Imine) and an amide formed by the reaction of a polyester having a free carboxylic acid group, a salt thereof, or the like; a water-based (meth) acrylic acid-styrene copolymer, (meth) acrylic acid- (meth) acrylic acid ester copolymer Polymers, styrene-maleic acid copolymers, polyvinyl alcohol, polyvinylpyrrolidone and other water-soluble resins and water-soluble polymer compounds; sodium lauryl sulfate, polyoxyethylene alkyl ether sulfate, sodium dodecylbenzene sulfonate, styrene-acrylic acid Alkali salt of copolymer, stearin Sodium, sodium alkyl naphthalene sulfonate, sodium alkyl diphenyl ether disulfonate, lauryl sulfate, monoethanolamine, triethanolamine lauryl sulfate, ammonium lauryl sulfate, monoethanolamine stearate,
Sodium stearate, sodium lauryl sulfate, styrene-acrylic acid copolymer monoethanolamine,
Anionic surfactants such as polyoxyethylene alkyl ether phosphate ester; polyoxyethylene oleyl ether, polyoxyethylene lauryl ether, polyoxyethylene nonylphenyl ether, polyoxyethylene alkyl ether phosphate ester, polyoxyethylene sorbitan monostea Rate, nonionic surfactants such as polyethylene glycol monolaurate;
Chaotic surfactants such as alkyl quaternary ammonium salts and their ethylene oxide adducts; amphoteric surfactants such as alkyl betaines such as alkyldimethylaminoacetic acid betaine and alkyl imidazolines, and these may be used alone or in combination of two or more. Can be mixed and used.

The content of the above-mentioned dispersant in the composition for liquid crystal panel is set so that the effect of further improving the dispersibility of the carbon black or the organic pigment coated with the resin is sufficiently expressed. It is preferable to adjust the amount to be 5 parts by weight or more, especially 10 parts by weight or more based on 100 parts by weight of the coated carbon black and the organic pigment, and the content of the carbon black or the organic pigment relatively coated with the resin. In order to increase the amount to increase the concentration and to efficiently perform ultraviolet curing or thermal curing of the liquid crystal panel composition, 60 parts by weight relative to 100 parts by weight of carbon black and the organic pigment coated with resin. It is preferable that the amount is adjusted to be not more than 40 parts by weight, especially 40 parts by weight or less.

When the organic pigment is contained, the surface resistivity after the heat history hardly changes, as compared with the case where the organic pigment is not contained.

This is because even if the resin on the surface of the carbon black coated with the resin flows by being subjected to heat history and the carbon black is exposed,
It is considered that this is because the organic pigment covers the exposed portion of the carbon black, so that the conductivity inherent in the carbon black is less likely to be exhibited by the organic pigment.

As the organic pigment, organic pigments having various hues such as blue, red, yellow, black, purple and green can be used. It is preferable that the organic pigments are appropriately mixed and used so that the hue becomes black.

When the organic pigment is intended to be irradiated with ultraviolet rays in the wavelength region of about 400 nm for photo-curing the composition for liquid crystal panel, the light transmittance in the wavelength region can be improved. It is preferably used in the liquid crystal panel composition of the present invention.

Among the above-mentioned organic pigments, for example, violet pigments (purple) and perylene pigments (black) are preferably used because they have a great effect of improving the light transmittance especially in the ultraviolet region.

Typical examples of the violet pigments include, for example, the general formula (I):

[0040]

Embedded image

(Wherein R ¹ and R ² each independently represents an alkyl group having 1 to 6 carbon atoms), such as a dioxazine pigment; a naphthol AS pigment such as naphthol violet; a halogenated Examples include slene-based pigments such as isoviolanthrone; basic dye lake-based pigments such as methyl violet lake, and these may be used alone or in admixture of two or more.

Typical examples of the perylene pigments include perylene black (CI Pigment Black 31), which may be used alone or in combination of two or more kinds.

When the dispersibility in the liquid crystal panel composition is taken into consideration, the organic pigment has an average particle size of usually about 0.05 to 1 μm, especially 0.1 to 0.5 μm.
It is preferable to use a grade.

The content of the organic pigment in the liquid crystal panel composition is 5% by weight or more, especially 10% by weight in order that the effect of improving the light transmittance of the organic pigment is sufficiently exhibited. It is preferable to adjust as described above, and in order to sufficiently increase the hiding power in the visible portion, it is preferably adjusted to 90% by weight or less, particularly 70% by weight or less.

When the composition for a liquid crystal panel is heat-cured, for example, the carbon black coated with the resin alone exhibits the same excellent effects as when the organic pigment is used.

Furthermore, in the composition for liquid crystal panel of the present invention, in addition to the above-mentioned dispersant and organic pigment, for example, a photopolymerizable monomer such as a monofunctional or polyfunctional (meth) acrylate monomer; polyester acrylate, Prepolymers such as polyurethane acrylates, epoxy acrylates, polyether acrylates, oligo acrylates, alkyd acrylates and polyol acrylates; photopolymerization initiators such as carbonyl compounds, sulfur compounds, azo compounds, organic peroxides; amine sensitizers; benzyl Trimethylammonium chloride, quaternary ammonium chloride such as diethylhydroxyamine, organic acid such as lactic acid and oxalic acid and its methyl ether,
A storage stabilizer such as t-butylpyrocatechol, an organic phosphine, a phosphite, a copper compound such as copper naphthenate, or the like can be contained by appropriately adjusting the content thereof.

The method for preparing the composition for liquid crystal panel of the present invention is not particularly limited, and for example, resin-coated carbon black and a dispersion medium, a dispersant, an organic pigment, a photopolymerizable monomer, a prepolymer, and a photopolymer are used. Polymerization initiator, sensitizer, type of storage stabilizer and the like, after appropriately adjusting the amount, for example, magnetic stirrer, paint shaker, Dynomill (registered trademark) (Bakofen horizontal sand mill, the same below), etc., A method of stirring and mixing at about 5 to 70 ° C. for about 1 to 50 hours and dispersing so as to obtain a uniform composition can be employed.

The viscosity of the thus obtained composition for liquid crystal panel is not particularly limited, but for example, TF of the liquid crystal panel is used.
Considering the handling property when forming the black matrix on the T side and controlling the film thickness of the film to be formed uniformly, at 25 ° C., about 10 to 2000 mPa · s,
It is preferably about 20 to 1000 mPa · s, especially.

The average particle diameter of the carbon black coated with the resin dispersed in the liquid crystal panel composition is
0.005 μm considering dispersion stability and fluidity
It is preferable that the thickness is not less than about 0.01 μm, more preferably not more than about 2.5 μm, especially not more than 1.5 μm in consideration of coloring power, blackness and dispersion stability.
It is preferable that it is not more than about. The average particle size of the carbon black coated with the resin may be almost the same as the average primary particle size of the original carbon black depending on the coating amount of the resin or the dispersion state.

There is no particular limitation on the method for forming a film on the TFT side of a liquid crystal panel using the composition for liquid crystal panel of the present invention. For example, spin coating, spraying, roll coating, etc. After coating the liquid crystal panel composition on the material surface,
A method of drying at about 280 ° C. for about 1 to 60 minutes, a method of curing with ultraviolet rays, or the like can be adopted.

Examples of the base material to which the liquid crystal panel composition of the present invention can be applied include glass substrates, plastic substrates such as polycarbonate and polymethylmethacrylate.

The film thickness of the film formed by the above method is not particularly limited when it is used as a black matrix in a liquid crystal display, but is usually about 0.5 to 2.5 μm. Preferably there is.

The surface resistivity of the coating can be measured according to the method described in the production example described later.

Considering, for example, the insulating property required for the black matrix, the surface resistivity of the film is preferably about 10 ¹⁰ Ω / □ or more, more preferably about 10 ¹² Ω / □ or more.

Further, after masking the film into a desired shape, it is exposed to ultraviolet rays and exposed to light, and the photocured film is developed to form a black matrix having a desired pattern. .

Since the composition for liquid crystal panel of the present invention contains not only simple carbon black but also carbon black coated with a resin, such a composition for liquid crystal panel is excellent in insulation and further colored. It has a large power and a high hiding power, and can be suitably used, for example, for forming a black matrix in a liquid crystal display or the like.

Next, the liquid crystal panel composition of the present invention will be described in more detail based on examples, but the present invention is not limited to these examples.

Production Example 1 Polyvinyl chloride (Nissan Vinyl E-manufactured by Nissan Kagaku Co., Ltd.)
Cyclohexanone was added to 430), and the mixture was heated to about 90 ° C. and dissolved therein to prepare a cyclohexanone solution containing 10% by weight of polyvinyl chloride. On the other hand, carbon black (furnace black, # 305 manufactured by Mitsubishi Chemical Corporation)
0, average primary particle size 0.04 μm, specific surface area 50 m ² /
g (BET method)) and water were mixed and vigorously stirred to prepare a uniform suspension containing 6% by weight of carbon black.

Next, the suspension was added to the cyclohexanone solution with stirring to transfer the carbon black in the aqueous phase to the solvent phase. Then, the water separated from the carbon black was removed by decantation, and then 80
The mixture was kneaded with a roll mill having two rolls heated to about 120 ° C. for about 5 minutes to obtain a resin composition.

Next, the resin composition was cut into a sheet with a heating roll, passed through a roll mill having two rolls at room temperature, crushed to a size of about 30 mm or less, transferred to water, and about 3000 rpm. The mixture was stirred at a speed of about 3 minutes for pulverization and sizing to obtain granules having a particle diameter of 0.1 to 3 mm, to obtain granules. 80 to 15 of this sized product
Drying at 0 ° C. yielded a resin-coated carbon black. With respect to the carbon black coated with the obtained resin, the coating amount of the resin with respect to carbon was examined by the following method.

In a 250 ml container, 20 g of resin-coated carbon black and 47 Efka
(Polyurethane-based dispersant manufactured by EFCA) 10 g and cellosolve acetate 70 g were added, and 200 g of glass beads having a diameter of 1 mm was added, followed by 1 with a paint shaker.
Shake for hours.

The obtained toner was diluted with cellosolve acetate so that the volume ratio was 2000 times.

The diluted liquid was placed in a quartz cell having a thickness of 10 mm, and a self-recorded spectrophotometer (U-3 manufactured by Hitachi, Ltd.) was used.
210), and the light transmittance T ₂ (%) of a liquid using a resin-coated carbon black at a wavelength of 550 nm.
Was measured.

The above steps (1) to (4) are carried out by using carbon black before coating with resin instead of the carbon black coated with resin, and the light transmittance T _{1 of} the liquid using the carbon black before coating with resin. (%) Was calculated.

The relationship between the apparent molecular extinction coefficient (ε), the liquid concentration (C) and the cell thickness (t) is given by the Lambert-Beer equation:

[0066]

[Equation 1]

(Where ε is the apparent molecular extinction coefficient, C is the concentration of the liquid (mol / l), t is the thickness of the cell, T ₀ is the light transmittance of the blank (100%), and T is the liquid). The light transmittance is shown).

Since the molecular extinction coefficient is unique to the molecule (here, carbon black) that absorbs light, when the cell thickness is constant,

[0069]

[Equation 2]

(In the formula, C ₁ is the concentration (mol / l) of the liquid of the carbon black before coating with the resin, and C ₂ is the carbon black of the liquid using the carbon black coated with the resin. (Mol / l), T ₀ is the same as above, T ₁ is the light transmittance of the liquid using the carbon black before coating with the resin, and T ₂ is the light beam of the liquid using the carbon black coated with the resin. Since the transmittance and λ are measurement wavelengths), the pure amount of carbon black was calculated using this formula.

Table 1 shows the resin coating amount (g) per 100 g of carbon black.

Further, after preparing a mixture of resin-coated carbon black and melamine resin containing 80% by weight of resin-coated carbon black in the total solid content, a spin coater was used to prepare a mixture of 1000 rp
m on a glass surface of 150 mm × 150 mm for 5 to 30 seconds and dried at 150 ° C. for 60 minutes to form a film having a thickness of 2.0 μm, which was then measured with a resistivity meter (HIRESTA IP MCP-manufactured by Mitsubishi Chemical Corporation). HT250)
The value of less than 10 ¹⁵ Ω / □ is measured by using HR-100 probe in accordance with JIS K-6911, and the surface resistivity (Ω /
□) was measured. Table 1 shows the results.

Production Example 2 Low molecular weight polyethylene (Plascon 617A manufactured by Allied Chemical Co., number average molecular weight 350)
0) was dissolved in xylene heated to 80 to 90 ° C. to prepare a xylene solution containing 10% by weight of polyethylene. On the other hand, carbon black (conductive carbon black, Vulcan XC-72 (registered trademark) manufactured by Cabot Corporation,
A specific surface area of 227 m ² / g (BET method)) and water were mixed and stirred vigorously to prepare a uniform suspension containing 3% by weight of carbon black.

Next, a xylene solution was added to the suspension and stirred to transfer the carbon black in the aqueous phase to the resin phase. After the mixture was further stirred to granulate carbon black and polyethylene, the obtained granules were separated, heated to 90 to 110 ° C. to remove xylene and remaining moisture, and coated with a resin. I got carbon black.

With respect to the carbon black coated with the obtained resin, the coating amount of the resin and the surface resistivity of the film were examined in the same manner as in Production Example 1. Table 1 shows the results.

Production Example 3 15 g of an acetone solution in which about 10% by weight of maleic anhydride was dissolved and carbon black (Furnace Black, # 3600 manufactured by Mitsubishi Chemical Co., Ltd., average primary particle diameter 0.016)
μm, specific surface area 1400 m ² / g (BET method)) 120
After being mixed with g in a Henschel mixer for about 5 minutes, the mixture was placed in an explosion-proof dryer and dried at 80 ° C. for 5 hours, and acetone was removed to obtain maleic anhydride-impregnated carbon black.

Next, 95 g of the carbon black impregnated with maleic anhydride and 5 g of 6-nylon were dry blended for 3 minutes with a Henschel mixer. At this time, calcium stearate and a lubricant (Irganox-1010 manufactured by Nippon Ciba-Geigy Co., Ltd.) were mixed with 0.4 of 6-nylon.
The carbon black coated with the resin was obtained by adding each by weight.

With respect to the carbon black coated with the obtained resin, the coating amount of the resin and the surface resistivity of the film were examined in the same manner as in Production Example 1. Table 1 shows the results.

Production Example 4 0.1 wt% of polyvinyl alcohol (PVA-205 manufactured by Kuraray Co., Ltd.) was dissolved in deionized water in a flask equipped with a stirrer, an inert gas introduction tube, a reflux condenser and a thermometer. 200 parts by weight of the prepared aqueous solution was charged. Then, in the flask, 8% by weight of benzoyl peroxide was added to a polymerizable monomer composed of 97% by weight of styrene and 3% by weight of glycidyl methacrylate, which had been prepared in advance.
108 parts by weight of the dissolved mixture was charged and stirred at high speed to prepare a uniform suspension. Then, while blowing nitrogen gas, the mixture was heated to 80 ° C., polymerization was carried out by continuing stirring at this temperature for 5 hours, and then cooled to obtain a polymer suspension.
The polymer suspension is filtered, washed and dried,
A polymer (epoxy resin) having an epoxy group as a reactive group was obtained.

Next, 20 parts by weight of the polymer having an epoxy group and carbon black (furnace black, MA-100R manufactured by Mitsubishi Chemical Co., Ltd., average primary particle diameter 0.022).
carbon black coated with a resin (carbon black graft) after being kneaded and reacted with 160 μm and a specific surface area of 134 m ² / g (BET method) 40 parts by weight under the conditions of 160 ° C. and 100 rpm. Polymer).

With respect to the carbon black coated with the obtained resin, the coating amount of the resin and the surface resistivity of the film were examined in the same manner as in Production Example 1. Table 1 shows the results.

Production Example 5 Styrene polymer (number average molecular weight 1600 to 1800)
Carbon black treated with 5 parts by weight of oil black Bs (manufactured by Orient Chemical Co., Ltd.) and 10% by weight of zinc stearate (furnace black, MA-100R manufactured by Mitsubishi Chemical Co., Ltd., average primary particle size of 0. 022
20 parts by weight of μm, specific surface area of 134 m ² / g (BET method) were mixed, kneaded and pulverized to obtain a resin-coated carbon black.

With respect to the carbon black coated with the obtained resin, the coating amount of the resin and the surface resistivity of the film were examined in the same manner as in Production Example 1. Table 1 shows the results.

Production Example 6 10 parts by weight of polyvinyl chloride and carbon black (furnace black, # 10 manufactured by Mitsubishi Chemical Corporation, average primary particle diameter 0.084 nm, specific surface area 28 m ² / g (BET
Method)) 90 parts by weight was previously mixed by stirring with a Henschel mixer for 5 minutes at 1000 rpm. Subsequently, 8 parts by weight of dioctyl phthalate as a plasticizer was added dropwise with stirring over 5 minutes.

With respect to the carbon black coated with the obtained resin, the coating amount of the resin and the surface resistivity of the film were examined in the same manner as in Production Example 1. Table 1 shows the results.

Production Example 7 Carbon black (furnace black, MA-100 manufactured by Mitsubishi Chemical Co., Ltd., average primary particle diameter 0.022 μm)
m, specific surface area 134 m ² / g (BET method)) 100 g and poly (2-ethyloxazoline) 20 g having a molecular weight of 100,000
Was stirred and mixed at 150 ° C. for 20 minutes using a blast mill. After the reaction, the mixture was cooled and pulverized to obtain surface-treated carbon black.

With respect to the carbon black coated with the obtained resin, the coating amount of the resin and the surface resistivity of the film were examined in the same manner as in Production Example 1. Table 1 shows the results.

Example 1 To 74 parts by weight of cellosolve acetate, 20 parts by weight of carbon black coated with the resin obtained in Production Example 1 and 6 parts by weight of a dispersant (high molecular weight polyurethane resin, weight average molecular weight 13000) were added. 2 using Dynomill
The mixture was stirred and mixed at 5 ° C. for 6 hours to obtain a liquid crystal panel composition having a good dispersion state and a uniform composition.

Next, 16 parts by weight of the liquid crystal panel composition was added to 66 parts by weight of a photopolymerizable monomer for ultraviolet curing (46 parts by weight of lauryl acrylate and 20 parts by weight of 2-hydroxyethyl acrylate) and a prepolymer (epoxy acrylate). ) 16 parts by weight, and a photopolymerization initiator (2-methyl- (4- (methylthio) phenyl) -2)
-Morpholino-1-propanone) 2 parts by weight,
The composition was used for measuring characteristics.

Using the obtained composition for property measurement, the composition of the liquid crystal panel was characterized by viscosity, optical density (hereinafter referred to as OD).
Value) and the average particle diameter of the carbon black coated with the resin were examined according to the following method. Table 2 shows the results.

(A) Viscosity The viscosity (mPa · s) was measured at 25 ° C. using a B type viscometer.

(B) OD value The OD value is a value representing the degree to which a substance absorbs light,
When the optical path length is constant, the larger the OD value, the higher the density of the coloring material. The OD value is obtained by diluting the composition for characteristic measurement with cellosolve acetate by 500 times in volume ratio, placing it in a cell having a thickness of 10 mm, and using a Macbeth (registered trademark) densitometer (TR-927 orthomatic type). It was

(C) Average Particle Size The average particle size (μm) of the carbon black coated with the resin dispersed in the filter composition was measured by Microtrac UPA particle size analyzer (Leeds & North Wrap Co.). (Leeds and North Ru
p)). Since carbon black is generally agglomerate of fine particles, the average particle diameter is considerably larger than the primary particle diameter.

Further, the composition for characteristic measurement was coated on a glass surface of 150 mm × 150 mm at 400 to 1000 rpm for 5 to 30 seconds using a spin coater, and dried at 150 ° C. for 60 minutes to give a thickness of 1.
A 2 μm film and a 2.0 μm thick film were formed.

With respect to the formed film, its physical properties were examined for OD value, light transmittance, surface resistivity and coloring state according to the following methods.

(1) OD Value Using the Macbeth densitometer, the OD value of a glass plate having a 1.2 μm thick film formed thereon was determined.

(2) Light transmittance Using a self-recording spectrophotometer (U-3210 manufactured by Hitachi, Ltd.), the light transmittance (%) of a 1.2 μm film in the wavelength range of 300 to 700 nm was measured. . The result is shown in FIG.

(3) Surface Resistivity The surface resistivity of a 2.0 μm thick film and a 2.0 μm thick film which was heat-treated at 250 ° C. for 1 hour were measured in the same manner as in Production Example 1. Table 2 shows the results.

(4) Coloring State A 1.2 μm film was visually observed to check its color and the presence or absence of color unevenness, and it was evaluated based on the following evaluation criteria.
Table 2 shows the results.

(Evaluation Criteria) A: Black with no color unevenness. B: Black, but there is partial color unevenness. C: Color unevenness is remarkable overall.

Example 2 In Example 1, 20 parts by weight of the resin-coated carbon black obtained in Production Example 2 was used, and 6 parts by weight of a polyacrylate having a weight average molecular weight of 20,000 was used as a dispersant. Was obtained in the same manner as in Example 1 to obtain a composition for liquid crystal panel and a composition for characteristic measurement, which had a good dispersion state and a uniform composition.

The characteristics of the obtained liquid crystal panel composition were examined in the same manner as in Example 1. The results are shown in Table 2.
Shown in

Further, using the above composition for measuring characteristics, a film having a thickness of 1.2 μm and a film having a thickness of 2.0 μm was formed in the same manner as in Example 1.

The physical properties of the formed film were examined in the same manner as in Example 1. The results are shown in Table 2 and FIG.

Example 3 In Example 1, 20 parts by weight of the resin-coated carbon black obtained in Production Example 3 was used, and 6 parts of a polyacrylate having a weight average molecular weight of 18,000 was used as a dispersant.
In the same manner as in Example 1 except that 74 parts by weight of 3-ethoxyethylpropionate was used as a dispersion medium and 15 parts by weight of dioxazine violet was further added as an organic pigment. Then, a composition for liquid crystal panel and a composition for measuring characteristics having a uniform composition were obtained.

The characteristics of the obtained liquid crystal panel composition were examined in the same manner as in Example 1. The results are shown in Table 2.
Shown in

Further, using the above-mentioned composition for measuring characteristics, a film having a thickness of 1.2 μm and a film of 2.0 μm was formed in the same manner as in Example 1.

The physical properties of the formed film were examined in the same manner as in Example 1. The results are shown in Table 2 and FIG.

Example 4 In Example 1, 20 parts by weight of the resin-coated carbon black obtained in Production Example 4 was used, and 74 parts by weight of propylene glycol monomethyl ether acetate was used as a dispersion medium. Further, as an organic pigment, perylene black (CI Pigment Black 3
1) In the same manner as in Example 1 except that 20 parts by weight was added, a liquid crystal panel composition and a characteristic measuring composition having a good dispersion state and a uniform composition were obtained.

The characteristics of the obtained liquid crystal panel composition were examined in the same manner as in Example 1. The results are shown in Table 2.
Shown in

Further, using the above composition for measuring characteristics, a film having a thickness of 1.2 μm and a film having a thickness of 2.0 μm was formed in the same manner as in Example 1.

The physical properties of the formed film were examined in the same manner as in Example 1. The results are shown in Table 2 and FIG.

Example 5 To 75 parts by weight of cellosolve acetate, 20 parts by weight of carbon black coated with the resin obtained in Production Example 5 and 5 parts by weight of a dispersant (high molecular weight polyurethane resin, weight average molecular weight 15000) were added. 2 using Dynomill
The mixture was stirred and mixed at 5 ° C. for 8 hours to obtain a composition for liquid crystal panel and a composition for characteristic measurement which had a good dispersion state and a uniform composition.

The characteristics of the obtained liquid crystal panel composition were examined in the same manner as in Example 1. The results are shown in Table 2.
Shown in

Further, using the above composition for measuring characteristics, a film having a thickness of 1.2 μm and a film having a thickness of 2.0 μm was formed in the same manner as in Example 1.

The physical properties of the formed film were examined in the same manner as in Example 1. Table 2 shows the results.

Example 6 In Example 1, 20 parts by weight of the resin-coated carbon black obtained in Production Example 6 was used, and 6 parts by weight of a polyacrylate having a weight average molecular weight of 25,000 was used as a dispersant. In the same manner as in Example 1, a liquid crystal panel composition having a good dispersion state and a uniform composition and a composition for measuring characteristics were obtained.

The characteristics of the obtained liquid crystal panel composition were examined in the same manner as in Example 1. The results are shown in Table 2.
Shown in

Further, using the above composition for measuring characteristics, a film having a thickness of 1.2 μm and a film having a thickness of 2.0 μm was formed in the same manner as in Example 1.

The physical properties of the formed film were examined in the same manner as in Example 1. Table 2 shows the results.

Example 7 In Example 1, 20 parts by weight of the resin-coated carbon black obtained in Production Example 7 was used, and 6 parts of a polyacrylate having a weight average molecular weight of 20,000 was used as a dispersant.
In the same manner as in Example 1 except that 70 parts by weight of methoxypropyl acetate was used as a dispersion medium and a dispersion medium was used, a composition for liquid crystal panel and a composition for measuring characteristics having a uniform and uniform composition were obtained. I got it.

The characteristics of the obtained liquid crystal panel composition were examined in the same manner as in Example 1. The results are shown in Table 2.
Shown in

Further, using the above composition for measuring characteristics, a film having a thickness of 1.2 μm and a film having a thickness of 2.0 μm was formed in the same manner as in Example 1.

The physical properties of the formed film were examined in the same manner as in Example 1. Table 2 shows the results.

Example 8 60 parts by weight of ion-exchanged water, 20 parts by weight of carbon black coated with the resin obtained in Production Example 1 and a dispersant (acrylic acid-styrene resin, solid content 20% by weight alkali neutralization) (Type) 20 parts by weight was added, and the mixture was stirred and mixed at 25 ° C. for 3 hours using a Dynomill, and coarse particles were removed with a 1 μm filter. A composition for liquid crystal panels having a good dispersion state and a uniform composition was obtained.

Next, 16 parts by weight of the liquid crystal panel composition, 80 parts by weight of a 5% by weight aqueous gelatin solution, 5 parts by weight of a photocurable resin (2-hydroxyethyl methacrylate-acrylamide copolymer), a photopolymerization initiator. (2,5-dimethoxy-4-morpholinobenzenediazonium) 0.2
It was diluted with 30 parts by weight of water and 30 parts by weight of water to obtain a composition for property measurement.

The characteristics of the obtained liquid crystal panel composition were examined in the same manner as in Example 1. The results are shown in Table 2.
Shown in

Further, using the above composition for measuring characteristics, a film having a thickness of 1.2 μm and a film having a thickness of 2.0 μm was formed in the same manner as in Example 1.

The physical properties of the formed film were examined in the same manner as in Example 1. Table 2 shows the results.

Example 9 To 74 parts by weight of ion-exchanged water, 20 parts by weight of the carbon black coated with the resin obtained in Production Example 2 and 6 parts by weight of a dispersant (polyoxyethylene nonylphenyl ether) were added, and Dynomil was added. After stirring and mixing at 25 ° C. for 5 hours with a filter, coarse particles were removed with a 1 μm filter. A composition for liquid crystal panels having a good dispersion state and a uniform composition was obtained.

Next, using the above liquid crystal panel composition,
Instead of the 5% by weight gelatin aqueous solution in Example 8, 5
A composition for measuring characteristics was obtained in the same manner as in Example 8 except that the weight% partially saponified polyvinyl acetate was used.

The characteristics of the obtained liquid crystal panel composition were examined in the same manner as in Example 1. The results are shown in Table 2.
Shown in

Further, using the above composition for measuring characteristics, a film having a thickness of 1.2 μm and a film having a thickness of 2.0 μm was formed in the same manner as in Example 1.

The physical properties of the formed film were examined in the same manner as in Example 1. Table 2 shows the results.

Comparative Example 1 Example 1 was repeated except that 20 parts by weight of carbon black not coated with resin (MA-11 manufactured by Mitsubishi Chemical Corporation) was used in place of the carbon black coated with resin in Comparative Example 1. In the same manner as in Example 1, a liquid crystal panel composition and a characteristic measuring composition were obtained.

The characteristics of the obtained liquid crystal panel composition were examined in the same manner as in Example 1. The results are shown in Table 2.
Shown in

Further, using the above composition for measuring characteristics, a film having a thickness of 1.2 μm and a film of 2.0 μm was formed in the same manner as in Example 1.

The physical properties of the formed film were examined in the same manner as in Example 1. Table 2 shows the results.

Comparative Example 2 In Example 1, instead of 20 parts by weight of carbon black coated with resin, phthalocyanine blue (C.I.
No. 74160) 5 parts by weight, dioxazine violet (C.I. No. 51319) 2 parts by weight, dianthraquinonyl red (C.I. No. 65300) 6 parts by weight, disazo yellow HR (C.I. No. 2110).
8) 3 parts by weight and phthalocyanine green (C.I.
No. 74260) Example 1 except that 4 parts by weight was used.
A composition for liquid crystal panel and a composition for measuring characteristics were obtained in the same manner as in.

The characteristics of the obtained liquid crystal panel composition were examined in the same manner as in Example 1. The results are shown in Table 2.
Shown in

Further, using the above composition for measuring characteristics, a film having a thickness of 1.2 μm and a film having a thickness of 2.0 μm was formed in the same manner as in Example 1.

The physical properties of the formed film were examined in the same manner as in Example 1. The results are shown in Table 2 and FIG.

[0143]

[Table 1]

[0144]

[Table 2]

As shown in Table 1, the surface resistivity is about 10
^The compositions for liquid crystal panels of Examples 1 to 9 obtained by dispersing resin-coated carbon black having a large value of ⁷ to 10 ¹⁵ Ω / □, as shown in Table 2, have OD values of 2. 6
From the above facts, it can be seen that the hiding property is excellent. Further, a film formed from such a composition,
Since the surface resistivity is as large as about 10 ¹³ to 10 ¹⁵ Ω / □ and the colored state is excellent, the compositions for liquid crystal panels of Examples 1 to 9 have excellent insulating properties and coloring and hiding powers. It turns out to be a big one.

Further, from the graphs shown in FIGS. 1 to 4, the liquid crystal panel compositions of Examples 1 to 4 have wavelengths of 350 to 6
It can be seen that the light transmittance in the visible region of about 50 nm is as low as about 5%, and the hiding property is excellent. In addition, in Examples 3 and 4, since the organic pigment is used, the light transmittance is slightly increased in the ultraviolet region having a wavelength of about 300 to 425 nm, and the ultraviolet curing of the liquid crystal panel composition is easier. I understand.

On the other hand, the composition for liquid crystal panel of Comparative Example 1 was
As shown in Table 2, although the OD value is large and the hiding property is excellent, the surface resistance is small and the insulating property is inferior because the carbon black not coated with the resin is used. Recognize. In addition, the composition for liquid crystal panel of Comparative Example 2 has a large surface resistance and excellent insulating property, but since only the coloring pigment is used, the OD value is as shown in Table 2 and FIG. It is clear that the light transmittance is small and the light transmittance in the visible region is as high as about 5 to 25%, and the hiding property is poor.

[0148]

EFFECT OF THE INVENTION The composition for liquid crystal panel of the present invention is excellent in insulating property and has large coloring power and hiding power. Therefore, for example, TF of liquid crystal panel such as liquid crystal display.
It can be suitably used for forming a black matrix on the T side.

[Brief description of drawings]

FIG. 1 is a graph showing the light transmittance of a film formed from the liquid crystal panel composition of Example 1.

FIG. 2 is a graph showing the light transmittance of a film formed from the liquid crystal panel composition of Example 2.

FIG. 3 is a graph showing the light transmittance of a film formed from the liquid crystal panel composition of Example 3.

FIG. 4 is a graph showing the light transmittance of a film formed from the liquid crystal panel composition of Example 4.

FIG. 5 is a graph showing the light transmittance of a film formed from the composition for liquid crystal panels of Comparative Example 2.

FIG. 6 is a cross-sectional view showing a liquid crystal panel in which a black matrix is provided on the thin film transistor side.

Claims (5)

[Claims] 1. A composition for a liquid crystal panel in which carbon black coated with a resin is dispersed in a dispersion medium. 2. The composition for a liquid crystal panel according to claim 1, wherein the content of the carbon black coated with the resin is 2 to 60% by weight. 3. The composition for liquid crystal panels according to claim 1, wherein the resin-coated carbon black has an average particle size of 0.005 to 2.5 μm. 4. The composition for liquid crystal panel according to claim 1, 2 or 3, which contains a dispersant. 5. The composition for liquid crystal panel according to claim 1, 2 or 3 containing an organic pigment.