KR101283474B1 - Black sealing agent composition for liquid crystal display materials - Google Patents

Abstract

When the black sealant for liquid crystal display elements which concerns on this invention is used, it can harden | cure by light and heat, and it is excellent in light shielding property, and can prevent the light leakage phenomenon of a liquid crystal cell. Moreover, the liquid crystal cell which has electrical insulation property, is excellent in moisture resistance, and has high adhesive force can be obtained.

Description

Black sealant composition for liquid crystal display element {BLACK SEALING AGENT COMPOSITION FOR LIQUID CRYSTAL DISPLAY MATERIALS}

This invention relates to the sealant composition used for a liquid crystal display element.

In recent years, flat panel displays have demanded excellent characteristics such as thinning, light weight, and low consumption strategy. Of these, liquid crystal display devices have been widely used in notebooks, netbooks, and televisions because of their excellent resolution, color display, and image quality.

BACKGROUND ART [0002] A liquid crystal display (LCD) that has been actively researched and developed is a type of flat panel display (FPD), and its overall structure is composed of two substrates and a liquid crystal interposed between the two substrates. In order to interpose the liquid crystal between the two substrates in the process of manufacturing such a liquid crystal display device, a process of applying the sealant composition to one of the two substrates, attaching the two substrates together, and then curing the sealant composition It must go through.

In this case, since the liquid crystal sealant is transparent or milky white, light leaks through the liquid crystal sealant when the liquid crystal is driven. When light leakage occurs, contrast decreases, and when bright characters, shapes, etc. are displayed on a dark display surface, when light leaks from the liquid crystal sealing part, the frame frame of the liquid crystal display is bright and cannot be used. In order to solve this problem, a method of preventing light leakage by adding titanium black or black pigment to a liquid crystal sealant to prevent light leakage has been proposed (Korean Patent Publication No. 1999-023240). However, since it is limited only to the method of hardening with heat using an epoxy resin or a noblock resin, it cannot be used in the liquid crystal dropping method according to the enlargement of a liquid crystal cell.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sealant composition for liquid crystal display devices used in the manufacture of liquid crystal display devices, and more particularly, by using black pigments, having high optical density, photocuring and thermal curing are possible, and storage. The black sealant composition for liquid crystal display elements which is excellent in stability and excellent in adhesive strength after hardening is provided.

Moreover, this invention provides the black sealant for liquid crystal display elements formed by photocuring and thermosetting the black sealant composition for liquid crystal display elements.

Sealant composition for a liquid crystal display device according to an embodiment of the present invention is 30 to 80 parts by weight of the modified epoxy resin containing a partial (meth) acrylate group, 10 to 40 parts by weight of black pigment, 1 to 10 parts by weight of the thermosetting agent, photopolymerization 1 to 7 parts by weight of initiator, and 0.01 to 7 parts by weight of additive.

The modified epoxy resin including the partial (meth) acrylate group is at least one selected from the group consisting of a novolak type epoxy resin, a biphenyl type epoxy resin, a naphthalene type epoxy resin, a trisphenol methane type epoxy resin, and a bisphenol type epoxy resin. It may be a species or more epoxy resin.

The modified epoxy resin including the partial (meth) acrylate group may have a viscosity of 1000 to 15000 cps before synthesis.

The black pigment may be at least one particle selected from the group consisting of chromium oxide, titanium black, cobalt oxide, carbon black and graphite.

The particle diameter of the particles may be 0.1 to 5μm.

The thermosetting agent may be a latent thermosetting agent that acts to cause thermal curing above 120 ° C.

The photopolymerization initiator is a benzoin compound, acetophenones, benzophenones, thioxanthones, anthraquinones, α-acyl oxime esters, phenylglyoxylates, benzyls, azo compounds, thiphenyl sulfide compounds , An acyl phosphine oxyvinyl compound, an organic dye compound, an iron-phthalocyanine compound, or the like can be used.

The additive may be a thixotropic modifier, a silane coupling agent, a photoinitiator, a leveling agent, a viscosity modifier, a surfactant, a plasticizer or an ultraviolet absorber.

The optical density of the sealant composition may be 0.4 or more at 1 μm.

The sealant composition for a liquid crystal display device may be photocurable and thermoset.

Sealant for liquid crystal display device according to another embodiment of the present invention is formed by curing the sealant composition for liquid crystal display device sealant.

When the black sealant for liquid crystal display elements which concerns on this invention is used, it can harden | cure by light and heat, and it is excellent in light shielding property, and can prevent the light leakage phenomenon of a liquid crystal cell. Moreover, the liquid crystal cell which has electrical insulation property, is excellent in moisture resistance, and has high adhesive force can be obtained.

The black sealant composition for a liquid crystal display device according to the present invention is a modified epoxy resin (hereinafter referred to as a partially (meth) acrylate modified epoxy resin) partially containing (meth) acrylate group, black pigment, thermosetting agent, photopolymerization initiator, Additives.

As the partial (meth) acrylate modified epoxy resin, a noblock type epoxy resin, a biphenyl type epoxy resin, a naphthalene type epoxy resin, a trisphenol methane type epoxy resin, a bisphenol type epoxy resin, or the like can be used. The epoxy resin may be used alone or in combination of two or more.

The said partial (meth) acrylate modified epoxy resin is obtained by making 0.5-1.8 equivalent of (meth) acrylic acid react with 2 equivalents of epoxy. As the catalyst used in the reaction, amines, inorganic alkali compounds and the like can be used. Specific examples of the amines include triethylamine, dimethylamine, trimethylamine, triethylamine, benzylmethylamine, and the like, and specific examples of the inorganic alkali compounds include sodium chromate and sodium hydrogencarbonate.

As the epoxy resin, bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol AD type epoxy resin, noblock type epoxy resin, naphthalene type epoxy resin, trisphenol methane type epoxy resin, glycidyl amine type epoxy resin and the like can be used. Do.

When the epoxy resin is used in the sealant composition for a liquid crystal display device, photocuring and thermosetting are enabled, and thus the liquid crystal dropping method can be used according to the enlargement of the liquid crystal cell.

As the epoxy resin, one having a viscosity of 1000 to 15000 cps before synthesis may be used, and preferably a resin having 5000 to 10000 cps may be used. By controlling the viscosity of the epoxy resin before synthesis, the viscosity of the partially (meth) acrylate-modified epoxy resin can be adjusted. The content of the partially (meth) acrylate modified epoxy resin is 30 to 80 parts by weight, preferably 40 to 70 parts by weight.

Although the kind of the black pigment is not particularly limited, black particles such as chromium oxide, titanium black, cobalt oxide, carbon black, and graphite may be used. The black pigments may be used alone or in combination of two or more. The black pigment may be one having a particle size of 0.1 to 5㎛ or less, and when the maximum particle diameter exceeds 5㎛, when the upper and lower glass substrates are bonded, the cell gap is not maintained, causing cell gap defects. Therefore, it is preferable to use 2 micrometers or less.

The content of the black pigment is preferably 10 to 40 parts by weight. When the content of the black pigment is less than 10 parts by weight, the optical density may be 0.4 / 1 μm or less, and light leakage may occur. When the content of the black pigment exceeds 40 parts by weight, the viscosity of the sealant composition may be excessively increased.

As the thermosetting agent, it is preferable to use a latent thermosetting agent that hardening does not occur at low temperature but hardening at high temperature. It is preferable to use a latent thermosetting material which causes the thermal curing to start at 120 ° C or higher. As the latent thermosetting agent, an imidazole type, dihydrazide type, amine type thermosetting agent may be used. In particular, it is preferable to use a dihydrazide type curing agent in order to prevent liquid crystal contamination of the liquid crystal display device to be produced and to improve adhesion to the substrate.

Specific examples of the imidazole type curing agent include 2-methylimidazole, 1,2-dimethylimidazole, 1-cyanoethyl-2-methylimidazole, P-0505 (manufactured by Shikoku Corporation), and the like. Can be. In addition, specific examples of the dihydrazide-type curing agent include amcure VDH, amcure UDH, amcure LDH (manufactured by Ajinomoto Co., Ltd.), ADH, SDH, DDH, IDH (manufactured by Otsuka Chemical Co., Ltd.) and NDH (manufactured by Nippon Hydrazine Industry Co., Ltd.). Can be mentioned. Moreover, as a specific example of an amine-type hardening | curing agent, amcure MY-24, amcure MY-H, amcure MY-HK, amcure PN-23, amcure PN-23J, amcure PN-23J, amcure PN-40J And Fuji Cure FXR-1020 and Fuji Cure FXR-1030 (manufactured by Fuji Kasei Co., Ltd.). The latent thermosetting agents may be used alone or in combination of two or more. The content of the thermosetting agent is 1 to 10 parts by weight.

Examples of the photopolymerization initiator include benzoin compounds, acetophenones, benzophenones, thioxanthones, anthraquinones, α-acyl oxime esters, phenylglyoxylates, benzyls, azo compounds, and thiphenyl sulfide compounds. And an acyl phosphine oxysulfate compound, an organic dye compound, an iron-phthalocyanine compound and the like. For example, benzophenone, 2, 2- diethoxy acetophenone, benzyl, benzoyl isopropyl ether, benzyl dimethyl ketal, 1-hydroxycyclohexyl phenyl ketone, thioxanthone, etc. are mentioned.

It is preferable to use an oxime ester compound for the said photoinitiator. Specifically, 1,2-octanedione 1- [4- (phenylthio) -2- (0-benzoyl oxime)] etc. which are represented by following General formula (1) are mentioned. As a commercial item of the oxime ester compound of following General formula (1), Irgacure OXE01 (made by BASF Corporation) etc. is mentioned, for example.

[Formula 1]

As content of the said photoinitiator, it is 1-7 weight part. When content of the said photoinitiator is less than 1 weight part, it may be hardening insufficiency. If it exceeds 7 parts by weight, liquid crystal contamination may occur or adhesion to the substrate may be reduced. Compounds that can be used as the photopolymerization initiator may be used alone or in combination of two or more.

As the additive, thixotropic agents and silane coupling agents may be used. In addition, a photoinitiation accelerator, a leveling agent, a viscosity modifier, a surfactant, a plasticizer, an ultraviolet absorber, and the like may be used.

Examples of the thixotropic regulator include methyl cellulose, methyl ethyl ketone peroxide, polyethylene oxide wax, modified polypropylene emulsion, polyamide wax, organic clay, alkyl sulfate, hydroxyl ethyl cellulose, hydroxyl esters, polyvinyl alcohol, polydimethyl Siloxanes, unsaturated carboxylic acid monomers, hydroxylated carboxylic acid monomers, hydroxide carboxylic acid amides, ethylene glycol, diethylene glycor alkaline earth metal hydroxides, alkaline earth metal carbonates and the like can be used.

Silane compounds which can be used as the silane coupling agent are, for example, γ-aminopropyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-isocyanato Propyl trimethoxysilane, etc. are mentioned. These silane compounds may be used alone or in combination of two or more.

The total content of the additives included in the composition is 0.01 to 7 parts by weight, preferably 0.1 to 5 parts by weight.

Sealant for liquid crystal display device according to another embodiment of the present invention is prepared by curing a sealant composition for a liquid crystal display device comprising a modified epoxy, a black pigment, a thermosetting agent, a photopolymerization initiator, and an additive containing a partial (meth) acrylate group do.

Since the sealant composition for a liquid crystal display device has the same configuration as described above, a description thereof will be omitted to avoid duplication.

Hereinafter, the present invention will be described in more detail with reference to specific embodiments. However, the technical spirit of the present invention is not limited by the following examples.

Synthetic example

700 g of liquid bisphenol A diglycidyl epoxy resin (KER-828, Kumho P & B Co., Ltd.) and a catalyst were added with 1 g of triethylamine and 2 g of 4-methoxyphenol, and the temperature was raised to 80 ° C while stirring. After sufficient mixing, 200 g of acrylic acid was added dropwise and stirred under reflux for 5 hours. Toluene and 1% oxalic acid were added to the obtained partial epoxy acrylate resin and stirred to remove ions, and then toluene and 1% oxalic acid were removed to obtain a partially (meth) acrylate-modified epoxy resin.

As a result of measuring the synthesized partial (meth) acrylate modified epoxy resin by GPC, 46% of the diacrylate resin in which the epoxy group was ring-opened by acrylic acid and the epoxy group was fully acrylated, 45% of the monoacrylate resin in which the epoxy group was partially acrylated, and 9% of unreacted epoxy resin was included.

Example

Example 1

60 g of partially (meth) acrylate-modified epoxy resin synthesized in the above synthesis example, 10 g of a thermosetting agent ADH (manufactured by Ajinomoto Co., Ltd.), 5 g of a photopolymerization initiator Irgacure OXE01 (manufactured by BASF), and a black pigment, carbon black pigment HIBLACK40B1 (manufactured by Evonik Co., Ltd.) 20 g, γ-glycidoxy propyl trimethoxy silane KBM-403 (manufactured by Shin-Etsu Co., Ltd.), a sufficient milling using a three-roll mill so as to be a uniform liquid after the first mixing through a premixing process And vacuum degassing treatment with a rotating revolving defoamer after the filter step to obtain a sealant composition.

Example 2

70 g of partial (meth) acrylate-modified epoxy resin synthesized in the above synthesis example, 10 g of thermosetting ADH (manufactured by Ajinomoto Co., Ltd.), 5 g of photopolymerization initiator OXE01 (manufactured by BASF), and 10 g of carbon black pigment HIBLACK40B1 (manufactured by Evonik Co., Ltd.) as a black pigment. The curable resin composition consisting of 5 g of γ-glycidoxypropyltrimethoxy silane KBM-403 (manufactured by Shin-Etsu Co., Ltd.) was sufficiently milled using a three-roll mill so as to be a uniform liquid after the first mixing through a premixing process. After the filter step, vacuum degassing was carried out using a rotating revolving deaerator to obtain a sealant composition.

Example 3

75 g of partial (meth) acrylate-modified epoxy resin synthesized in the above synthesis example, 10 g of a thermosetting agent ADH (manufactured by Ajinomoto Co., Ltd.), 5 g of a photopolymerization initiator Irgacure OXE01 (manufactured by BASF), and a black pigment, carbon black pigment HIBLACK40B1 (manufactured by Evonik Co., Ltd.) 5 g, γ-glycidoxy propyl trimethoxy silane KBM-403 (manufactured by Shin-Etsu Co., Ltd.) 5 m of curable resin composition is sufficiently milled using a three-roll mill so as to be a uniform liquid after primary mixing through a premixing process. After the filter step, a vacuum degassing treatment was performed using a rotating revolving deaerator to obtain a sealant composition.

Example 4

40 g of partial (meth) acrylate-modified epoxy resin synthesized in the above synthesis example, 10 g of thermosetting ADH (manufactured by Ajinomoto Co., Ltd.), 5 g of photopolymerization initiator Irgacure OXE01 (manufactured by BASF Co., Ltd.), and black pigment HIBLACK40B1 (manufactured by Evonik Co., Ltd.) Milling is sufficiently performed using a three-roll mill so that the curable resin composition consisting of 40 g and 5 g of γ-glycidoxypropyltrimethoxy silane KBM-403 (manufactured by Shin-Etsu Co., Ltd.) is subjected to the first mixing through a premixing process to form a uniform liquid. After the filter step, a vacuum degassing treatment was performed using a rotating revolving deaerator to obtain a sealant composition.

Example 5

30 g of partial (meth) acrylate-modified epoxy resin synthesized in the above synthesis example, 10 g of thermosetting ADH (manufactured by Ajinomoto Co., Ltd.), 5 g of photopolymerization initiator Irgacure OXE01 (manufactured by BASF), and black pigment as black pigment HIBLACK40B1 (manufactured by Evonik Co., Ltd.) 50 g, γ-glycidoxy propyl trimethoxy silane KBM-403 (manufactured by Shin-Etsu Co., Ltd.), a sufficient amount of milling using a three-roll mill so as to be a uniform liquid after primary mixing through a premixing process. After the filter step, a vacuum degassing treatment was performed using a rotating revolving deaerator to obtain a sealant composition.

evaluation

For the evaluation of the obtained composition, the analysis and measurement were performed through the following procedure.

1. Stability of viscosity change with time (daily average viscosity change rate, viscosity change rate after 7 days)

The sealant composition obtained in Example 1 was distributed in a small amount in a vial and left at room temperature to measure a change in viscosity from 1 day to 7 days. Viscometer used was Brookfield's "RVDV II + pro" product. The measurement conditions were measured at the temperature of 25 degreeC, spindle # 29, and the spindle speed of 1.0 rpm. The viscosity change rate after 7 days was converted into the viscosity change rate after the initial viscosity and 7 days of aging, and the value divided by the conversion day was calculated as the daily average viscosity increase rate.

In the case where the viscosity change rate is within 100%, and in the case of 100% or more, it is shown in Table 1 as Ｘ.

2. Optical density (Optical characteristic experiment)

To 25 g of the sealant composition obtained in Example 1, 1.25 g of silica having a diameter of 5 μm was added as a spacer for maintaining a cell gap, mixed with a rotating revolving deaerator, and then degassed to remove bubbles. Thereafter, the obtained sealant was applied to the upper portion of the ITO glass using a dispenser equipment, and then photocured using UV and pressure using a cementing machine, and then thermally cured in an oven at 120 ° C. for 1 hour to obtain a measurement sample. . At this time, Shotmaster 300S manufactured by Musashi Co., Ltd. was used, and a dispensing nozzle was applied under conditions of 250 μm and a discharge pressure of 100 KPa. The width of the dispensed sealant composition was 1.5 mm and the UV curing energy was 2 J / cm 2. Next, this glass substrate was placed in a spectroscopic spectrum measuring apparatus, and the optical density was measured.

The optical density converted into 1 micrometer in thickness is 0.4 or more, and it is shown in Table 1 that it is less than 0.4 that it is less than 0.4.

3. Evaluation of cleaning power

5 g of the sealant for the liquid crystal display element is added to the SUS cup before curing, and left to stand for 1 hour to be spread out on the bottom of the cup. Acetone is used as a washing solvent, 500 g of solvent is added thereto, and the washing is performed with an ultrasonic cleaner (Sonicator, 521O, manufactured by Branson).

○: less than 20 minutes

Ｘ: 20 minutes or more

4. Measurement of adhesion strength

After curing, the sealant for liquid crystal display elements was applied to the center of the cleaned ITO glass substrate (manufactured by Samsung Corning), and the same ITO glass substrate was laminated thereon, followed by UV curing (2J / cm2) and thermal curing (120 ° C, 1 hour). ) The obtained specimen was measured for adhesion strength using a UTM instrument (HK5T, manufactured by Tinius Olsen).

5. Liquid crystal reactivity evaluation (phase transition temperature ( Tni )Measure)

The sealant before curing was brought into contact with a liquid crystal (manufactured by Merck, TN, VA), cured, and measured at a heating rate of 10 deg. C / min using a DSC measuring device to measure the peak temperature. 1g of sealant was added to the ampoule bottle, 1g of liquid crystal was added to the ampoule bottle, and left for 1 hour, UV cured (2J / cm2), thermal curing (120 ° C, 1 hour), and then the temperature rising rate using a DSC measuring device. The Tni value of the blank liquid crystal was measured at 10 ° C / min, and the Tni value of the advanced sample was measured and evaluated. The closer the Tni value was to the Tni value of the blank liquid crystal, the lower the contamination on the liquid crystal.

(Circle): value change to less than 0.5 degreeC

Ｘ: change in value above 0.5 ° C

6. Photocurable  evaluation

The black sealant for liquid crystal display elements was sandwiched between glass. In that state, light was irradiated with a metal halide lamp so that light irradiation amount might become 2J / cm <2>. Then, the reaction rate of acryl was measured by the analysis method using FT-IR.

○: acrylic reaction rate 70% or more

△: acrylic reaction rate 50 or more ~ less than 70%

Ｘ: less than 50% acrylic reaction rate

Ingredient (unit: g) Example 1 Example 2 Example 3 Example 4 Example 5 Curable resin Modified Epoxy Resin ⁽¹⁾ 60 70 75 40 30 Thermosets ⁽⁴⁾ 10 10 10 10 10 Photopolymerization initiator ⁽⁵⁾ 5 5 5 5 5 Black Filler ⁽⁶⁾ 20 10 5 40 50 Silane Coupling Agents ⁽⁷⁾ 5 5 5 5 5 Viscosity Stability ○ ○ ○ X X Optical density ○ ○ X ○ ○ Cleanliness ○ ○ ○ X X Adhesive strength ○ ○ ○ ○ ○ Liquid crystal reactivity ○ ○ ○ X X Hardenability ○ ○ ○ △ X

* Day

(1): Acrylate modified epoxy resin manufactured by the synthesis example

(2): partially acrylated epoxy resin (Diessel UCB, UVAC1561)

(3): Bisphenol A type epoxy acrylate (Diesel UCB company, EB3700)

(4): dihydrazide thermosetting agent (Azicure Co., VDH)

(5): Oxime ester type photoinitiator (BASF, Irgacure OXE01)

(6): carbon black pigment (Evonik, HIBLACK40B1)

(7): γ-glycidoxypropyltrimethoxy silane (Shin-Etsu Corp., KBM-403)

Claims (11)

30 to 80 parts by weight of the modified epoxy resin containing a partial (meth) acrylate group, wherein the proportion of the unreacted epoxy resin is less than 10%;
10 to 40 parts by weight of black pigment;
1 to 10 parts by weight of a thermosetting agent; And
1 to 7 parts by weight of the photopolymerization initiator;
Sealing agent composition for a liquid crystal display device comprising a and induces a phase transition temperature change of less than 0.5 ℃ compared to the phase transition temperature (Tni) of the blank liquid crystal.
The method of claim 1,
The modified epoxy resin including the partial (meth) acrylate group is at least one selected from the group consisting of a novolak type epoxy resin, a biphenyl type epoxy resin, a naphthalene type epoxy resin, a trisphenol methane type epoxy resin, and a bisphenol type epoxy resin. Sealing agent composition for liquid crystal display elements characterized by the above-mentioned epoxy resin.
The method of claim 1,
The modified epoxy resin containing the partial (meth) acrylate group is a sealing agent composition for a liquid crystal display device, characterized in that the viscosity of the epoxy resin before synthesis is 1000 to 15000cps.
The method of claim 1,
The black pigment is a sealing agent composition for a liquid crystal display device, characterized in that at least one particle selected from the group consisting of chromium oxide, titanium black, cobalt oxide, carbon black and graphite.
5. The method of claim 4,
The particle diameter of the said particle | grain is 0.1-5 micrometers, The sealing compound composition for liquid crystal display elements characterized by the above-mentioned.
The method of claim 1,
The thermosetting agent is a latent thermosetting agent which acts to cause thermal curing at 120 ℃ or more, the sealing agent composition for a liquid crystal display element.
The method of claim 1,
The photopolymerization initiator is a benzoin compound, acetophenones, benzophenones, thioxanthones, anthraquinones, α-acyl oxime esters, phenylglyoxylates, benzyls, azo compounds, thiphenyl sulfide compounds And at least one compound selected from the group consisting of an acyl phosphine oxyvinyl compound, an organic dye compound and an iron-phthalocyanine compound.
The method of claim 1,
A liquid crystal display further comprising 0.01 to 7 parts by weight of at least one additive selected from the group consisting of thixotropic modifiers, silane coupling agents, photoinitiators, leveling agents, viscosity modifiers, surfactants, plasticizers and ultraviolet absorbers. Sealing agent composition for devices.
The method of claim 1,
The optical density of the said sealing agent composition is 0.4 or more in 1 micrometer, The sealing agent composition for liquid crystal display elements characterized by the above-mentioned.
The method of claim 1,
Photocuring and thermosetting are possible, The sealing compound composition for liquid crystal display elements characterized by the above-mentioned.
The sealant for liquid crystal display elements formed by hardening the sealant composition for liquid crystal display elements of Claim 1.