JPH09304760A - Composition for liquid crystal panel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a compsn. for a liquid crystal panel having large shielding power and excellent insulating property by composing the compsn. of an oxidized carbon black, a dispersant having an electron donating group and a dispersion medium. SOLUTION: A compsn. composed of an oxidized carbon black, a dispersant having an electron donating group and a dispersion medium is used for a liquid crystal panel. Namely, by using the oxidized carbon black, the obtd. compsn. for a liquid crystal panel has excellent insulating property. By using both of the oxidized carbon black and the dispersant having an electron donating group, excellent physical properties required for a black matrix are obtd. such that the oxidized carbon black has excellent insulating property and shows enough coloring power and shielding power which are intrinsic properties of the carbon black. As for the dispersant having an electron donating group, any dispersant can be used as far as it can be dissolved in the dispersion medium.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a composition for a liquid crystal panel. More specifically, it relates to a composition for a liquid crystal panel, which has a large hiding power and an excellent insulating property and can be suitably used, for example, for forming a black matrix in a liquid crystal panel.

[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 comprising carbon black and a color pigment of a different color other than carbon black. Is disclosed.

[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. 1 is provided with 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 having a large hiding power and an excellent insulating property.

[0013]

The present invention relates to a composition for a liquid crystal panel comprising an oxidation-treated carbon black, a dispersant having an electron donating group and 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 includes an oxidation-treated carbon black, a dispersant having an electron-donating group, and a dispersion medium.

One of the major features of the present invention is that oxidation-treated carbon black is used as the carbon black.

Since the oxidation-treated carbon black is used in the present invention, the liquid crystal panel composition of the present invention exhibits excellent insulating properties.

The present invention is also characterized in that the oxidation-treated carbon black and a dispersant having an electron donating group are used in combination.

In the present invention, since the oxidation-treated carbon black and the dispersant having an electron-donating group are used in combination, the oxidation-treated carbon black exhibits excellent insulating properties, and the carbon black is The excellent physical properties required for the black matrix are exhibited, that is, the coloring power and the hiding power that are inherently exhibited. In the present invention, the reason why such excellent physical properties are expressed is not clear, but there is probably some chemical behavior between the acidic group of the oxidized carbon black and the electron-donating group of the dispersant. It is considered that this is because the dispersant lowers the electrical conductivity originally possessed by the oxidation-treated carbon black, thereby increasing the insulating property of the oxidation-treated carbon black. Further, it is considered that some chemical behavior occurs between the dispersant and the oxidation-treated carbon black, but since a strong chemical bond is not formed between the two, the oxidation-treated carbon It is considered that the coloring property and the hiding power inherently possessed by black are not lost, and the coloring is sufficiently exhibited. In the liquid crystal panel composition of the present invention, as described above, some chemical behavior is considered to occur between the oxidation-treated carbon black and the dispersant, but both are
Since it is uniformly dispersed, the viscosity of the liquid crystal panel composition of the present invention does not extremely rise, and the film formed by using the liquid crystal panel composition is provided with appropriate mechanical strength. It also has excellent adhesion to the base material,
Excellent physical properties are expressed.

Examples of the carbon black used as a raw material for the oxidation-treated carbon black used in the present invention include channel black, acetylene black, furnace black and the like. These may be used alone or in admixture of two or more. You can

The average primary particle diameter of the carbon black is not particularly limited, but in consideration of dispersibility in the liquid crystal panel composition, it is usually about 5 to 200 nm, preferably about 10 to 100 nm.

The specific surface area of carbon black is not particularly limited, but it is measured by the BET method in order to reduce the inherent conductivity of carbon black and to impart sufficient insulation. Value is usually 20-1500
m ² / g approximately, is preferably inter alia 50~1400m ² / g approximately.

The oxidation-treated carbon black can be obtained by subjecting the carbon black to an oxidation treatment.

The carbon black may be oxidized by heating the carbon black in air at a temperature of about 150 to 250 ° C. for about 10 to 20 days, or at a temperature of about 50 to 100 ° C. for 0.5. Examples include a method of heat-treating carbon black for about 1.5 hours and a method of heating carbon black in an aqueous nitric acid solution at a temperature of about 50 to 150 ° C. for 1.5 to 2.5 hours. Thus, when the carbon black is subjected to the oxidation treatment, the amount of carbonyl groups and carboxyl groups existing on the surface of the carbon black increases.

The degree of the oxidation treatment to which the carbon black is applied can be quantitatively defined by pH and volatile matter.

The pH of the oxidation-treated carbon black is
20 g of the oxidized carbon black is distilled water (pH 7.
0), boiled for 5 minutes, cooled to room temperature, and measured by measuring the pH of the muddy oxidized carbon black with a glass electrode pH meter. The pH is preferably 2 or more in order to improve the dispersibility, and is preferably 5 or less in order to improve the insulating property.

The nonvolatile content is 2 g of oxidation-treated carbon black in an absolutely dry platinum crucible having an internal capacity of 10 ml.
, And heat it for 10 minutes in an electric furnace whose temperature is adjusted to 950 ° C., then put it in a desiccator and cool it to room temperature.
It is determined by dividing the weight after drying by the weight of the oxidized carbon black before drying. The nonvolatile content is preferably 1.5% by weight or more in order to improve the insulating property, and is preferably 20% by weight or less in order to improve the dispersibility.

In the present invention, as described above, the dispersant having an electron donating group is used.

The dispersant having an electron-donating group may be any that can be dissolved in the dispersion medium. As a representative example of such a dispersant, for example, in the case of oiliness, polyurethane, polycarboxylic acid ester such as polyacrylate,
Unsaturated polyamide, polycarboxylic acid (partial) amine salt,
Polycarboxylic acid ammonium salt, polycarboxylic acid alkylamine salt, polysiloxane, long-chain polyaminoamide phosphate, hydroxyl group-containing polycarboxylic acid ester and modified products thereof, poly (lower alkyleneimine) and free carboxylic acid group Amides and salts thereof formed by reaction with polyesters having; in water, (meth) acrylic acid-styrene copolymer, (meth) acrylic acid- (meth) acrylic acid ester copolymer, styrene-maleic acid copolymer Water-soluble resin or water-soluble polymer compound such as polymer, polyvinyl alcohol, polyvinylpyrrolidone; sodium lauryl sulfate, polyoxyethylene alkyl ether sulfate, sodium dodecylbenzenesulfonate, alkali salt of styrene-acrylic acid copolymer, stearic acid Sodium, alkyl naphthalene Sodium ruphonate, sodium alkyldiphenyl ether disulfonate, monoethanolamine lauryl sulfate, triethanolamine lauryl sulfate, ammonium lauryl sulfate, monoethanolamine stearate, sodium stearate, sodium lauryl sulfate, monoethanolamine of styrene-acrylic acid copolymer 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 mono Nonionic surfactants such as stearate and polyethylene glycol monolaurate; alkyldimethyl Mino alkyl betaines, such as acetic acid betaine, and amphoteric surfactants such as alkyl imidazoline, and these alone, or two
A mixture of more than one species can be used.

Among these, the dispersant in which the electron-donating group is an amino group has excellent dispersibility, and therefore,
It can be preferably used in the present invention. Examples of the dispersant in which the electron-donating group is an amino group include Disperbyk-130, -101, -161,-.
162, -163, -164, -165, -166,-
170 (above, manufactured by Big Chemie Japan Ltd.); E
FKA-47, -47EA, -48, -49, -10
0, -400, -450 (above, manufactured by EFKA); Sols Perth 13240, 13940, 17000, 24.
000GR, 28000, 20000, 12000, 2
7000 (above, manufactured by Zeneca Corporation) and the like.

Further, as the dispersant having an electron donating group, a polymer having a comb structure which is excellent in surface adhesion of the oxidized carbon black is preferable.

Examples of the dispersion medium used in the present invention include cellosolve acetate solvents such as cellosolve acetate, propylene glycol monomethyl ether acetate, 3-methoxybutyl acetate, methoxypropyl acetate and 2-methoxyethyl acetate;
Organic solvents such as hydrocarbon compounds having an ether bond and an ester bond such as ethoxyethyl propionate and propylene glycol monomethyl ether propionate, and water are preferably used.

The liquid crystal panel composition of the present invention comprises, as described above, an oxidation-treated carbon black, a dispersant having an electron donating group, and a dispersion medium.

The content of the oxidation-treated carbon black in the composition for liquid crystal panel is 2% by weight so that the effect of imparting the coloring power and the hiding power by the oxidation-treated carbon black is sufficiently exhibited. As described above, it is preferable to adjust the content to 5% by weight or more, and the viscosity of the liquid crystal panel composition is not excessively increased so that the handling property is not deteriorated, and the obtained liquid crystal panel composition is excellent. In order to impart the insulating property and to improve the mechanical strength of the film formed of the composition for liquid crystal panel and the adhesion to the substrate, the content is adjusted to 80% by weight or less, and particularly 60% by weight or less. It is preferable.

The amount of the dispersant having an electron-donating group used is such that the oxidation-treated carbon black 10 is used in order to impart sufficient insulating properties to the obtained liquid crystal panel composition.
It is preferably 1 part by weight or more, especially 5 parts by weight or more with respect to 0 parts by weight, and 100 parts by weight with respect to 100 parts by weight of the above-mentioned oxidation-treated carbon black in order to sufficiently develop the hiding power of the oxidation-treated carbon black. It is preferably not more than 60 parts by weight, especially not more than 60 parts by weight.

It should be noted that, with the oxidation-treated carbon black,
In order to prevent adsorption with the dispersant having an electron donating group and improve dispersibility, it is preferable to add a coupling agent to the liquid crystal panel composition of the present invention. Further, among the above-mentioned coupling agents, the coupling agent having an unsaturated ethylenic double bond is copolymerized with the component having an unsaturated ethylenic double bond contained in the composition. In the above, it is particularly preferably used. Typical examples of such coupling agents include γ-methacryloxypropyltrimethoxysilane.

The amount of the coupling agent used is 5 parts by weight based on 100 parts by weight of the oxidized carbon black in order to sufficiently suppress the adsorption of the oxidized carbon black and the dispersant having an electron-donating group. The amount is preferably not less than 20 parts by weight, more preferably not less than 20 parts by weight, and in order to reduce the change in viscosity with time, the amount is not more than 100 parts by weight, and not more than 80 parts by weight, relative to 100 parts by weight of the oxidized carbon black. Is preferred.

In order to prevent the heat resistance from deteriorating even when the film formed from the liquid crystal panel composition of the present invention is subjected to heat treatment at about 200 to 300 ° C., for example, It is preferable to add a heat-resistant resin to the liquid crystal panel composition of the present invention.

Typical examples of the heat-resistant resin include fluorine resin, silicone resin, silicon-containing acrylic resin, polyimide, polyimide amide, polydiphenyl ether, poly (alkylene imine), phenol resin,
Examples include xylene resin and epoxy resin. These heat resistant resins may be used alone or in combination of two or more.

The amount of the heat-resistant resin used is 3% by weight or more, especially 5% by weight, in order to impart sufficient heat resistance to the liquid crystal panel composition of the present invention. It is preferable to adjust as described above, and when the composition contains a photopolymerizable monomer and a prepolymer which will be described later, in order to sufficiently proceed the crosslinking reaction of both, the liquid crystal It is preferable to adjust the content in the panel composition to 50% by weight or less, particularly 30% by weight or less.

The liquid crystal panel composition of the present invention may contain, for example, an organic pigment, if necessary.

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):

[0045]

Embedded image

(Wherein R ¹ and R ² each independently represent an alkyl group having 1 to 6 carbon atoms), such as dioxazine pigments; naphthol AS pigments such as naphthol violet; 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 admixture of two or more.

When the dispersibility in the composition for liquid crystal panel 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 so 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.

Furthermore, in the composition for liquid crystal panel of the present invention, in addition to the above organic pigment, for example, a photopolymerizable monomer such as a monofunctional or polyfunctional (meth) acrylate-based monomer; polyester acrylate, polyurethane acrylate, Prepolymers such as 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; benzyltrimethylammonium chloride , Quaternary ammonium chlorides such as diethylhydroxyamine, organic acids such as lactic acid and oxalic acid, and their methyl ethers, t-butylpyrocatechol, organic phosphines, phosphites, copper compounds such as copper naphthenate Which storage stabilizer and the like, may be contained by appropriately adjusting the content thereof.

The method for preparing the liquid crystal panel composition of the present invention is not particularly limited, and includes, for example, oxidation-treated carbon black, a dispersant having an electron-donating group and a dispersion medium, and if necessary, an organic pigment and a photopolymerizable property. After appropriately adjusting the types and amounts of the monomers, prepolymers, photopolymerization initiators, sensitizers, storage stabilizers, etc., use, for example, a magnetic stirrer, paint shaker, sand mill, ball mill, roll mill or the like at 5 to 70 ° C. 1 to 5
For example, a method of stirring and mixing for about 0 hour to disperse so as to have a uniform composition can be adopted.

The viscosity of the liquid crystal panel composition thus obtained 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 size of the oxidation-treated carbon black dispersed in the liquid crystal panel composition is about 0.005 μm or more, especially about 0.01 μm or more, considering dispersion stability and fluidity. Further, in consideration of coloring power, blackness and dispersion stability, it is preferably about 2.5 μm or less, particularly about 1.5 μm or less.

There is no particular limitation on the method of 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 composition for liquid crystal panel 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 the film is 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. .

The composition for liquid crystal panel of the present invention uses not only simple carbon black but oxidation-treated carbon black, and further contains a dispersant having an electron-donating group. The composition is
It has excellent insulating properties, and has a large coloring power and a large hiding power, and can be suitably used for forming a black matrix in liquid crystal displays and the like.

[0061]

EXAMPLES 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.

Example 1 Oxidized carbon black (furnace black, average primary particle size 24 nm, specific surface area 137 m ² / g, pH
3.0 parts by weight, 3.5 parts by weight of volatile matter) and 6 parts by weight of a dispersant having an amino group as an electron donating group and a comb structure (Solsperse 24000 manufactured by Zeneca Corp.) are used as a dispersion medium (cellosolve acetate). ) It was added to 74 parts by weight and stirred and mixed at 25 ° C. using a sand mill to obtain a composition for liquid crystal panel having a good dispersion state and a uniform composition.

Next, in order to examine the physical properties of the liquid crystal panel composition, a composition for measuring physical properties was prepared according to the following methods.

First, 25 parts by weight of a prepolymer (epoxy acrylate), 10 parts by weight of a photopolymerizable monomer (3 parts by weight of lauryl acrylate, 3 parts by weight of methyl methacrylate, 3 parts by weight of 2-hydroxyethyl acrylate and 1 part by weight of methacrylic acid). ) And 65 parts by weight of cellosolve acetate, 2 parts by weight of a photopolymerization initiator (2-methyl- (4- (methylthionophenyl) -2-morpholino 1-propanone)) were added, and the resin solution for dilution was added. Prepared.

40 parts by weight of the liquid crystal panel composition, 40 parts by weight of the diluting resin liquid, and Cellosolve acetate 2
0 parts by weight were mixed and stirred to obtain a composition for measuring physical properties.

The obtained composition for measuring physical properties was applied to a glass plate with a spin coater and dried at 150 ° C. for 60 minutes,
A film having a thickness of about 1 μm was formed.

As the physical properties of the formed film, the optical density (hereinafter referred to as OD value) and the surface resistivity were examined according to the following methods. Table 1 shows the results.

(A) 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 of the glass plate on which the film having a thickness of about 1 μm was formed was measured using a Macbeth (registered trademark) densitometer (TR).
-927 orthomatic type).

(B) Surface resistivity The film having a thickness of about 1 μm was heat-treated at 150 ° C. for 60 minutes, and the film having a surface resistivity of about 1 μm was formed.
The surface resistivity after heat treatment at 50 ° C for 60 minutes is measured by a surface resistance meter (Mitsubishi Chemical Co., Ltd., Hiresta IP).
(MCP-HT250).

Example 2 Oxidized carbon black (furnace black, average primary particle size 29 nm, specific surface area 104 m ² / g, pH
3.5 parts, volatile matter 2.0% by weight), 20 parts by weight, 6 parts by weight of a dispersant having an amino group as an electron-donating group and a comb structure (Solsperse 28000 manufactured by Zeneca Corp.) and a silane coupling agent. 4 parts by weight of vinyl ethoxysilane as a dispersion medium (3-ethoxyethyl propionate) 7
It was added to 0 parts by weight, and stirred and mixed at 25 ° C. using a sand mill to obtain a liquid crystal panel composition having a good dispersion state and a uniform composition.

Next, in order to investigate the physical properties of the liquid crystal panel composition, a composition for measuring physical properties was prepared according to the following methods.

First, 25 parts by weight of a prepolymer (epoxy acrylate), 10 parts by weight of a photopolymerizable monomer (4 parts by weight of lauryl acrylate, 3 parts by weight of methyl acrylate, 2 parts by weight of styrene and 1 part by weight of acrylic acid) and 3- After diluting with 65 parts by weight of ethoxyethyl propionate, 2 parts by weight of a photopolymerization initiator (2-methyl- (4- (methylthionophenyl) -2-morpholino 1-propanone)) was added to the resin solution for dilution. Was prepared.

40 parts by weight of the liquid crystal panel composition, 40 parts by weight of the diluting resin liquid and 20 parts by weight of ethoxyethyl propionate were mixed and stirred to obtain a composition for measuring physical properties.

The obtained composition for measuring physical properties was applied to a glass plate with a spin coater and dried at 150 ° C. for 60 minutes,
A film having a thickness of about 1 μm was formed.

As the physical properties of the formed film, the optical density (hereinafter referred to as OD value) and the surface resistivity were examined in the same manner as in Example 1. Table 1 shows the results.

Example 3 Oxidized carbon black (furnace black, average primary particle diameter 31 nm, specific surface area 65 m ² / g, pH 3.
0, volatile matter 2.5% by weight), 20 parts by weight, 6 parts by weight of a dispersant having an amino group as an electron donating group (manufactured by Big Chemie Japan KK, Disperbyk-161) and vinyltriethoxy as a silane coupling agent. 4 parts by weight of silane as a dispersion medium (methoxypropyl acetate) 7
It was added to 0 parts by weight, and stirred and mixed at 25 ° C. using a sand mill to obtain a liquid crystal panel composition having a good dispersion state and a uniform composition.

Next, in order to examine the physical properties of the liquid crystal panel composition, a composition for measuring physical properties was prepared according to the following methods.

First, 25 parts by weight of a prepolymer (oligoester acrylate), 10 parts by weight of a photopolymerizable monomer (3 parts by weight of lauryl acrylate, 3 parts by weight of methyl acrylate, 3 parts by weight of 2-hydroxyethyl acrylate and 1 part by weight of acrylic acid). Part) and 65 parts by weight of methoxypropyl acetate and diluted with a photopolymerization initiator (2
2 parts by weight of -methyl- (4- (methylthio) phenyl) -2-morpholin) -1-propanone) was added to prepare a resin solution for dilution.

40 parts by weight of the liquid crystal panel composition, 30 parts by weight of the diluting resin solution, 10 parts by weight of thermoplastic polyimide and 20 parts by weight of methoxypropyl acetate were mixed and stirred to obtain a composition for measuring physical properties.

The obtained composition for measuring physical properties was applied to a glass plate with a spin coater and dried at 150 ° C. for 60 minutes,
A film having a thickness of about 1 μm was formed.

As the physical properties of the formed film, the optical density (hereinafter referred to as OD value) and the surface resistivity were examined according to the method of Example 1. Table 1 shows the results.

Comparative Example 1 Oxidized carbon black (furnace black, average primary particle size 23 nm, specific surface area 130 m ² / g, pH
8.0, volatile content 1.1% by weight) 20 parts by weight and dispersant (manufactured by BYK Japan KK, Disperby)
6 parts by weight of (k-170) was added to 70 parts by weight of a dispersion medium (cellosolve acetate), and the mixture was stirred and mixed at 25 ° C. using a sand mill to obtain a composition for liquid crystal panel having a good dispersion state and a uniform composition.

Next, in order to examine the physical properties of the liquid crystal panel composition, a composition for measuring physical properties was prepared according to the following methods.

First, 25 parts by weight of a prepolymer (epoxy acrylate), 10 parts by weight of a photopolymerizable monomer (3 parts by weight of lauryl acrylate, 3 parts by weight of methyl acrylate, 3 parts by weight of 2-hydroxyethyl acrylate and 1 part by weight of acrylic acid). ) And cellosolve acetate 65
After dilution with parts by weight, a photopolymerization initiator (2-methyl-
2 parts by weight of (4- (methylthionophenyl) -2-morpholinatoppropanone) was added to prepare a resin solution for dilution.

40 parts by weight of the liquid crystal panel composition, 40 parts by weight of the diluting resin liquid, and cellosolve acetate 2
0 parts by weight were mixed and stirred to obtain a composition for measuring physical properties.

The obtained composition for measuring physical properties was applied to a glass plate with a spin coater and dried at 150 ° C. for 60 minutes,
A film having a thickness of about 1 μm was formed.

As the physical properties of the formed film, the optical density (hereinafter referred to as OD value) and the surface resistivity were examined in the same manner as in Example 1. Table 1 shows the results.

Comparative Example 2 Untreated carbon black (furnace black, average primary particle diameter 30 nm, specific surface area 85 m ² / g, pH 8.
0, a nonvolatile content of 0.6% by weight) and 6 parts by weight of a dispersant having an amine group as an electron donating group (Disperbyk-165, manufactured by BYK Japan KK) 74 parts by weight of a dispersion medium (cellosolve acetate). The resulting mixture was stirred and mixed at 25 ° C. using a sand mill to obtain a composition for liquid crystal panel having a good dispersion state and a uniform composition.

Next, in order to investigate the physical properties of the liquid crystal panel composition, a composition for measuring physical properties was prepared according to the following methods.

First, 25 parts by weight of a prepolymer (epoxy acrylate), 10 parts by weight of a photopolymerizable monomer (3 parts by weight of lauryl acrylate, 3 parts by weight of methyl acrylate, 3 parts by weight of 2-hydroxyethyl acrylate and 1 part by weight of acrylic acid). ) And cellosolve acetate 65
After dilution with parts by weight, a photopolymerization initiator (2-methyl-
(4- (methylthionophenyl) -2-morpholino-
2 parts by weight of 1-propanone) was added to prepare a resin solution for dilution.

40 parts by weight of the liquid crystal panel composition, 40 parts by weight of the diluting resin liquid, and Cellosolve acetate 2
0 parts by weight were mixed and stirred to obtain a composition for measuring physical properties.

The obtained composition for measuring physical properties was applied to a glass plate with a spin coater and dried at 150 ° C. for 60 minutes,
A film having a thickness of about 1 μm was formed.

As the physical properties of the formed film, the optical density (hereinafter referred to as OD value) and the surface resistivity were examined in the same manner as in Example 1. Table 1 shows the results.

[0094]

[Table 1]

As shown in Table 1, since the OD values of the compositions for liquid crystal panels of Examples 1 to 3 are as large as 2.9 or more, it can be seen that they have excellent concealing properties. A film formed from such a composition has a surface resistivity of 15
Approximately 10 for both 0 ° C and 250 ° C heating
^Since it is as large as ¹² Ω / □ or more, it can be seen that it has excellent insulation properties.

On the other hand, as shown in Table 1, the liquid crystal panel compositions of Comparative Examples 1 and 2 all have large OD values and excellent concealing properties, but have low surface resistance and insulating properties. It turns out to be inferior.

[0097]

EFFECT OF THE INVENTION The composition for liquid crystal panel of the present invention is excellent in insulating property and has a large hiding power, so that it is suitably used for forming a black matrix on the TFT side of a liquid crystal panel such as a liquid crystal display. be able to.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a liquid crystal panel in which a black matrix is provided on the side of a conventional thin film transistor.

Claims (6)

[Claims] 1. A liquid crystal panel composition comprising an oxidized carbon black, a dispersant having an electron donating group, and a dispersion medium. 2. The oxidized carbon black has a pH of 2-5.
The composition for a liquid crystal panel according to claim 1, which has a volatile content of 1.5 to 20% by weight. 3. The composition for a liquid crystal panel according to claim 1, wherein the electron donating group contained in the dispersant is an amino group. 4. The composition for a liquid crystal panel according to claim 3, wherein the dispersant having an electron donating group is a polymer having a comb structure. 5. The composition for a liquid crystal panel according to claim 1, which contains a coupling agent having an unsaturated ethylenic double bond. 6. A heat-resistant resin-containing resin according to claim 1,
The composition for liquid crystal panel according to 2, 3, 4 or 5.