KR20090072291A - Composition of overcoat layer for liquid crystal display device - Google Patents

Abstract

An overcoat layer composition is provided to maintain uniform thickness of a liquid crystal layer due to an overcoat layer with low thickness variation, and to prevent liquid crystal layer form being eluted from the overcoat layer. An overcoat layer composition of a liquid crystal display comprises a polymer binder 5~10 weight% having a repeating unit represented by chemical formula 1; a monomer 1~5 weight% having a multifuntcional group; an anhydride hardener 1~5 weight%; an initiator 0.1~2 weight; an inhibitor 0.1~1 weight%; an adhesion promoter 0.1~1 weight%; a surfactant 0.1~1 weight%; and solvent for balancing.

Description

Composition of overcoat layer for liquid crystal display device

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to liquid crystal displays, and more particularly to compositions of materials for forming overcoat layers of liquid crystal displays.

Recently, liquid crystal displays have been spotlighted as next generation advanced display devices having low power consumption, good portability, high technology value, and high added value.

Among the liquid crystal display devices, an active matrix liquid crystal display device having a thin film transistor, which is a switching element that can control voltage on / off for each pixel, has the best resolution and video performance. It is attracting attention.

In general, an LCD device forms an array substrate and a color filter substrate through an array substrate manufacturing process for forming a thin film transistor and a pixel electrode, and a color filter substrate manufacturing process for forming a color filter and a common electrode, respectively. It completes through the liquid crystal cell process through a liquid crystal between them.

In more detail, the configuration of a general liquid crystal display device will be described.

A general liquid crystal display device includes a lower substrate on which a thin film transistor, a pixel electrode, and the like are formed, an upper substrate disposed to face the same, and a liquid crystal interposed between the lower and upper substrates. It comprises a layer.

In the lower substrate, a plurality of gate lines and a plurality of data lines cross each other to define a pixel area. Each pixel region includes a thin film transistor connected to the gate and data lines, and a transparent pixel electrode connected to the thin film transistor. The thin film transistor may include a gate electrode, a gate insulating layer, a semiconductor layer including an active layer and an ohmic contact layer, a source electrode, and a drain electrode, wherein the gate electrode is on the gate wiring and the source electrode is the data. Connected to the wiring. In addition, a passivation layer including a drain contact hole exposing the drain electrode is formed on the thin film transistor, and the pixel electrode is connected to the drain electrode through the drain contact hole and is formed on the passivation layer. .

Meanwhile, a black matrix made of an opaque material corresponding to non-display areas such as the thin film transistors, gates, and data lines is formed in a lattice shape around the pixel area in the upper substrate, and red and green colors correspond to the pixel areas. A color filter layer containing a blue color filter is formed. A transparent common electrode forming an electric field with the pixel electrode is formed on the color filter layer. When an electric field is formed by the pixels and the common electrode, the liquid crystal layer interposed therebetween is driven to represent an image.

At this time, in order to planarize the black matrix and the color filter layer before forming the common electrode, an overcoat layer made of an insulating material is formed on the entire surface. That is, the common electrode is formed on the overcoat layer having a flat upper surface, thereby forming a uniform electric field with the lower pixel electrode. Therefore, one of the properties required for the overcoat layer should not change thickness (dimension) due to process temperature or the like. It is. The same applies to a so-called transverse electric field type liquid crystal display device in which a common electrode is formed on a lower substrate. In this case, a high temperature process is performed in forming an alignment layer formed on an overcoat layer, and thus heat resistance is required. In addition, since the overcoat layer should not have a thickness change in order to keep the cell gap between the upper and lower substrates constant, this characteristic becomes more important. In addition, if foreign matter is eluted from the overcoat layer, it may cause a problem of contamination of the liquid crystal layer, and thus requires chemical stability.

In the overcoat layer requiring such characteristics, a polyolefin-based material is conventionally used as a polymer binder, but some problems have arisen in the overcoat layer having such a composition. That is, since the polyolefin-based binder polymer has a glass transition temperature (Tg) of 150 ° C. or lower, its heat resistance is low, which causes a decrease in the heat resistance of the overcoat layer. And since the fall of heat resistance causes the thickness change by process temperature, it also raises a problem also in dimensional stability. In addition, the overcoat layer material is eluted under the above process conditions, thereby causing a problem of contaminating the liquid crystal. In addition, with the polyolefin-based binder polymer, the composition of the column spacer has a linear structure and thereby has a low crosslinking density, and thus has a brittle property. In addition, due to the lack of compatibility with the main material with a lot of aromatic (aromatic) component requires the addition of a compatibilizer.

An object of the present invention is to provide an overcoat layer having a property of improving heat resistance and having a small degree of dissolution of foreign substances in an overcoat layer of a liquid crystal display device.

By the overcoat layer having the above characteristics, even when a high temperature process is performed, the thickness change is minimized so that the cell gap can be kept constant, and the flatness of the common electrode is improved to improve the uniformity of the electric field. .

And, to minimize the contamination of the liquid crystal layer.

In order to solve the above problems, the present invention is a polyester-based, polyamide-based or polythioether-based polymer binder 5 to 10% by weight, 1 to 5% by weight of a monomer having a polyfunctional group, 1 to 5% by weight of anhydride curing agent, To provide a composition for an overcoat layer of a liquid crystal display device comprising 0.1 to 2 wt% of an initiator, 0.1 to 1 wt% of an inhibitor, 0.1 to 1 wt% of an adhesion promoter, 0.1 to 1 wt% of a surfactant, and a residual amount of a solvent.

According to the present invention, in particular, even if a high temperature process is performed after the overcoat layer is formed, the decrease in the thickness change is reduced compared with the prior art. That is, since the heat resistance characteristic is improved and the thickness change is reduced, the thickness of the liquid crystal layer can be kept uniform and the liquid crystal layer can be completely prevented from leaking out.

In addition, since the amount of the material eluted from the overcoat layer is only about half of that of the related art, the possibility of contamination of the liquid crystal is reduced, whereby defects such as afterimages and stains are solved, thereby providing a liquid crystal display device having improved display quality. .

The present invention is to provide an overcoat layer composition of a liquid crystal display device having improved heat resistance characteristics and the like to minimize the change in thickness, in particular, characterized in that the polyester polymer, polyamide polymer or polythioether polymer as a binder. .

And the overcoat layer composition for a liquid crystal display device according to an embodiment of the present invention is 5 to 10% by weight of the polymer binder as described above, 1 to 5% by weight monomer having a polyfunctional group, 1 to 5% by weight of anhydride curing agent, initiator (initiator) ) 0.1 to 2% by weight, 0.1 to 1% by weight of inhibitor (inhibitor), 0.1 to 1% by weight of adhesion promoter (adhesion promoter), 0.1 to 1% by weight of surfactant and the remaining amount of the solvent.

Here, the monomer having a multifunctional group is a compound having three or more functional groups, and specifically, an acrylate compound such as trimethylolpropane triacrylate (TMPTA), pentaerythritol triacrylate, pentaerythritol tetracrylate, dipentaerythritol monohydroxy pentacrylate, YP50 (Kukdo Chemical Co., Ltd.). , Manufactured), YF128 (manufactured by K & C KM), and YDF170 (manufactured by Toto Chemical Co.). In addition, the initiator includes a thermal initiator and a photoinitiator, and as a thermal initiator, a compound having a peroxide, a persulfate, an azo group, etc. is used, and as a photoinitiator, IG907, IG369, IG184 (above Sivaga) Ciba Geigy Co., Ltd.) etc. are used. Acetone peroxide-based compounds are used as inhibitors, and glycol-based compounds are used as adhesion promoters. In addition, as the surfactant, BYK333, BYK352 (above manufactured by BYK-Chemie) and silicone-based compounds are used, and as a solvent, Propylene Glycol Methyl Ether Acetate (PGMEA) is used.

In addition, when the polymer binder is photocurable, both a photocuring agent and a thermosetting agent are included, and the ratio of the photocuring agent and the thermosetting agent is about 1: 2.

First, the polymeric binder which is a characteristic of this invention is demonstrated.

Polyester-based polymers, polyamide-based polymers or polythioether-based polymers are all represented by the following formula (1) or (2).

Formula 1

Formula 2

Here, m + n = 1, and 0 ≦ m ≦ 1 and 0 ≦ n ≦ 1 are satisfied. In formula (1), the case where R ₂ = R ₃ , R ₄ = R ₅ is represented by formula (2).

In Formula 1 and Formula 2, R ₁ is selected from any one of the following Formulas 3a to 3d.

Formula 3a

Formula 3b

Formula 3c

Chemical formula 3d

In addition, in Formula 3a, X is

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It is selected from any one of, wherein 0≤m≤10, 0≤n≤10 is satisfied. That is, in Formula 3a, X is a benzene compound substituted with alkoxyalkyl, alkyl or alkoxyalkyl, an aromatic ether compound, an amine, an alkoxy amine, a benzene compound having an amine group, or the like.

In addition, Y in Formula 3a is

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It may be selected from the group consisting of materials. In this case, each of 1 to 9 displayed above is as follows.

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It can be selected from the group of substances consisting of (hereinafter referred to as 'Y-1 substance group'), 0≤m≤10, 0≤n≤10, each of A and B are H, F, Cl, CN, Selected from CF3 or CH3.

In addition, in Formulas 3b and 3c, 0 ≦ n ≦ 10 is satisfied, and each of 1 to 5 is selected from any one of the materials of the Y-1 material group, where 0 ≦ m ≦ 10 and 0 ≦ n ≦ 10. And A and B are each selected from H, F, Cl, CN, CF ₃ or CH ₃ .

In addition, in Formula 3d, Y is

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It can be selected from the group consisting of materials, where 0≤n≤10 is satisfied.

And, in Formula 3d 1 and 2 are each

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It may be selected from the group consisting of materials, wherein A is any one selected from H, F, CH ₃ , CF ₃ , CN. That is, in Formula 3d, 1 and 2 are each one selected from H, F, CH ₃ , CF ₃ , CN, cyclopentane, and cyclohexane.

In Formula 1, the connection of R ₂ and R ₄ , R ₃ and R ₄ , R ₃ and R ₅ , and the connection of R ₂ and R ₄ in Formula 2 may be performed by various forms. When the binder represented by 2 is a polyester type polymer, it is obtained by reaction of a diol and carboxylic acid like following Reaction Formula 1.

Scheme 1

Specifically, in the case of the polyester-based polymer, R ₂ and / or R ₃ of Formula 1 or 2 is

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It may be selected from the group consisting of materials, wherein 0≤m≤10, 0≤n≤10, and A and 1 to 8 are each one of H, F, Cl, CN, CF ₃ or CH ₃ . That is, R 2 and / or R 3 of Formula 1 or 2 are aliphatic alcohol compounds, alicyclic alcohol compounds, or aromatic alcohol compounds having 1 to 30 carbohydrates.

In addition, in the case of the polyester polymer, R ₄ and / or R ₅ of Formula 1 or 2,

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It can be selected from the group of substances consisting of (hereinafter referred to as "Y-2 group of substances"), where 0≤m≤10, 0≤n≤10 is satisfied. That is, R ₄ and / or R ₅ of Formula 1 or 2 as the polyamide-based advertising molecule is one of carboxylic acid compounds containing an alicyclic or aromatic compound, wherein the carbon number is 1 to 30.

Example  1: photocurable Triazine system polyester  Containing polymer Overcoat layer Formation of

Photocurable triazine-based polyester polymer of the polyester-based polymer as described above was obtained by the following synthesis process, to form an overcoat layer using this.

(1) Introduction of alcohol functional group

90 g of 4- (2-tetrahydropyranyloxy) bromobenzene was dissolved in a three-necked flask filled with nitrogen with 500 ml of tetrahydrofuran and reacted with 9.6 g of magnesium for 3 hours. 18.4 g of cyanuric chloride was added dropwise to a solution in which 200 ml of tetrahydrofuran was dissolved, and the reaction was carried out at a temperature at which the solvent was refluxed for about 6 hours. After the reaction was completed, 3 g of pyridinium paratoluene sulfonate was added to the reaction solution, and the reaction was further performed for 6 hours. After completion of the reaction, the reaction mixture was distilled under reduced pressure to remove tetrahydrofuran, dissolved in methylene chloride, passed through a filter filled with silica gel, and then distilled under reduced pressure to remove the solvent. Finally, the mixture was recrystallized from a 1: 1 mixed solvent of methylene chloride and normal hexane, followed by filtration under reduced pressure. The obtained solid substance was dried in vacuo to give 2,4,6-trihydroxyphenyl-1,3,5-triazine, and the yield was 71% to give 25.3 g.

(2) Synthesis of Diol Monomer Having Cinnamoyl Functional Group

14.8 g of cinnamic acid was placed in a round-bottomed flask filled with nitrogen and stirred by adding 17.8 g of thionyl chloride (SOCl 2). Then, 0.5 ml of dimethylformamide (DMF) was further added to the flask, followed by reaction at room temperature for 24 hours. After the reaction was completed, distillation under reduced pressure was carried out to obtain 16 g of cinnamoyl chloride. 35.7 g of 2,4,6-trihydroxyphenyl-1,3,5-triazine obtained above was put into a round bottom flask and dissolved in 400 ml of chloroform.

After adding 15.2 g of triethylamine to the solution, the temperature was lowered to -5 ° C, and 16 ml of cinnamoyl chloride obtained above was added dropwise to 20 ml of tetrahydrofuran from which water was removed. The reaction was stirred for 12 hours. After completion of the reaction, the reaction solution was distilled under reduced pressure to remove tetrahydrofuran, dissolved in methylene chloride, passed through a filter filled with silica gel, and then distilled under reduced pressure to remove the solvent. Finally, after recrystallization in a 1: 1 mixed solvent of methylene chloride and normal hexane, and filtered under reduced pressure. The obtained solid substance was dried in vacuo to prepare a diol monomer having a cinnamoyl functional group, which yielded 29.7 g as 61%.

(3) Polymerization of Polyester Photosensitive Polymer Having Cinamate Photosensitive Functional Group

48.7 g of the diol monomer obtained by the method of (2) was placed in a round bottom flask filled with nitrogen, dissolved in 400 ml of toluene dehydrated, and 20.238 g of triethylamine was added thereto. After dissolving 20.3 g of terephthaloyl chloride in 100 ml of toluene, the mixture was stirred vigorously while being slowly added dropwise to the solution of the previous triazine monomer and triethyl amine, and reacted for 12 hours. After completion of the reaction, the reaction solution was slowly poured into methanol, precipitated and filtered, and the precipitate was dried in vacuo. The obtained precipitate was dissolved again in tetrahydrofuran and then precipitated in methanol twice. After vacuum drying, a polyester polymer having a cinnamate photosensitive functional group was finally prepared using a triazine ring.

(4) Formation of Overcoat Layer

In the above-mentioned composition of the overcoat layer, 8 g of the polyester polymer prepared in (3) was mixed on the basis of 100 g of the composition having no binder mixed therein, and the mixed solution was coated on a substrate and baked at 150 ° C. for 10 minutes. After UV (energy density of 1.5 J / cm 2 based on the wavelength of 365nm) irradiation was carried out. After completion of UV irradiation, the resultant was calcined again at 230 ° C. for 1 hour to form an overcoat layer on the substrate.

Example  2 : Thermosetting Triazine system polyester  Containing polymer Overcoat layer  Formation of

The thermosetting triazine-based polyester polymer of the polyester-based polymer was obtained by the following synthesis process, and the overcoat layer was formed using the same.

(1) Preparation of N-hydroxymaleimide

 42.26 g of N- (phenyloxycarbonyloxy) maleimide (II) is dissolved in 500 ml of methanol and refluxed for 3 hours. After the reaction, methanol was evaporated to remove the residue, and the remaining liquid was poured into benzene to obtain a solid. This solid was recrystallized using a mixed solvent of tetrahydrofuran (THF) and hexane to give 12.60 g of N-hydroxymaleimide in a yield of 62%. The crystal melting point was measured at 125 ° C., consistent with the values reported (125-126 ° C.) in the literature (Akiyama, M., et al., J. Chem. Soc., Perkin 1 1980, 2122).

(2) Preparation of triazine substituted with maleimide

11.3 g of N-hydroxymaleimide was dissolved in 100 ml of THF. After 3 g of NaH was added thereto, the reaction was carried out for 2 hours, and the reaction solution was slowly added dropwise at -20 ° C to a solution of 18.4 g of triazine dissolved in THF, followed by further reaction for 1 hour after the dropping was completed. Proceeded. After completion of the reaction, the THF was removed from the solution, the salt component in the solid phase was removed, and recrystallized from a mixed solution of methylene chloride and normal hexane to prepare a triazine compound substituted with maleimide. The yield was 15.7 g as 60%. .

(3) Preparation of Triazine Monomer

26.1 g of a triazine compound substituted with maleimide was dissolved in 200 ml of THF. 90 g of 4- (2-tetrahydropyranyloxy) bromobenzene was dissolved in a three-necked flask filled with nitrogen with 500 ml of tetrahydrofuran and reacted with 9.6 g of magnesium for 3 hours. The solution was added dropwise to a THF solution substituted with maleimide and reacted at a temperature at which the solvent was refluxed for about 6 hours. After the reaction was completed, 3 g of pyridinium paratoluene sulfonate was added to the reaction solution, and the reaction was further performed for 6 hours. After completion of the reaction, the reaction mixture was distilled under reduced pressure to remove tetrahydrofuran, dissolved in methylene chloride, passed through a filter filled with silica gel, and further distilled under reduced pressure to remove the solvent. Finally, after recrystallization in a 1: 1 mixed solvent of methylene chloride and normal hexane, and filtered under reduced pressure. The resulting solid phase was dried in vacuo to give a triazine monomer, yielding 24.4 g as 65%.

(4) Polymerization of Polyester Polymer Having Maleimide Group

37.5 g of the triazine monomer obtained by the method of (3) was placed in a round bottom flask filled with nitrogen and dissolved in 400 ml of toluene dehydrated. 20.238 g of triethylamine is added to this solution. After dissolving 20.3 g of terephthaloyl chloride in 100 ml of toluene, the mixture was stirred vigorously while slowly dropping into the solution of the previous triazine monomer and triethyl amine, followed by reaction for 12 hours. After completion of the reaction, the reaction solution was slowly poured into methanol, precipitated and filtered, and the precipitate was dried in vacuo. The obtained precipitate was again dissolved in tetrahydrofuran and then precipitated in methanol. The process was repeated two times, followed by vacuum drying to finally prepare a polyester polymer having a maleimide functional group using a triazine ring.

(5) Formation of Overcoat Layer

In the above-mentioned composition of the overcoat layer, 8 g of the polyester polymer prepared in (4) was mixed based on the weight of 100 g of the composition having no binder mixed, and the mixed solution was coated on a substrate and baked at 150 ° C. for 10 minutes. Thereafter, the substrate was refired at 230 ° C. for 1 hour to form an overcoat layer on the substrate.

Next, the polyamide-based polymer will be described.

In the case of the polyamide-based polymer, it is represented by the same chemical formula as the polyester-based polymer described above. That is, it is represented by Formula 1 or Formula 2, R1 is also the same. On the other hand, R2, R3, R4, and R5 are different from polyester-based polymers, whereby they are characterized. That is, the linkage of R ₂ -R ₄ , R ₃ -R ₄ , and R ₃ -R ₅ in Formula 1 and the linkage of R ₂ -R ₄ in Formula 2 are obtained by the reaction of an amine and a carboxylic acid.

At this time, the R ₂ and R ₃ in Formula 1, in Formula 2, R ₂ is as above and the amine of the amine and carboxylic acid reaction, in particular the formula (I) or (II) of the R ₂ and / or R ₃ is

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It can be selected from the group consisting of materials, where 0≤m≤10, 0≤n≤10 is satisfied. That is, when including a polyamide-based advertising molecule, R ₂ and / or R ₃ of the formula (1) or 2 is one of the amine compound containing an alkylamine compound, alkoxyamine compound, alkylbenzyl or alkoxybenzyl compound, wherein Carbon number is 1-30.

On the other hand, in the case of a polyamide-based advertising molecule, R ₄ and / or R ₅ of the general formula (1) or (2) is a carboxylic acid, it may be selected from the Y-2 material group, where 0≤m≤10, 0≤n≤ Meets 10 That is, R ₄ and / or R ₅ of Formula 1 or 2 as the polyamide-based advertising molecule is one of carboxylic acid compounds containing an alicyclic or aromatic compound, wherein the carbon number is 1 to 30.

Example  3: Cinnamate A functional group  Containing a polyamide-based polymer having Overcoat layer  formation

The polyamide-based polymer having a cinnamate functional group is obtained by the following process, which is the case where R ₁ in Formula 1 or Formula 2 is Formula 3a.

(1) Introduction of cinnamate functional group

First, 14.8 g of cinnamic acid was placed in a round bottom flask filled with nitrogen, and 17.8 g of thionyl chloride (SOCl 2) was added thereto, followed by stirring. Then, 0.5 ml of dimethylformamide (DMF) was further added to the flask, followed by reaction at room temperature for 24 hours. After the reaction was completed, distillation under reduced pressure was carried out to obtain 16 g of cinnamoyl chloride.

(2) Synthesis of Triazine Rings with Side Chains

Next, 18.4 g of cyanuric chloride was added to a round bottom flask filled with nitrogen, and 200 ml of tetrahydrofuran from which moisture was removed was dissolved. After adding 15.2 g of triethylamine to the solution and lowering the temperature to -5C, the dilute cinnamic chloride solution was slowly added dropwise to the cinnamoyl chloride obtained by adding 20 ml of dehydrogenated tetrahydrofuran and slowly dropping it. The reaction was stirred for a while. After completion of the reaction, the reaction solution was distilled under reduced pressure to remove tetrahydrofuran, dissolved in methylene chloride, passed through a filter filled with silica gel, and then distilled under reduced pressure to remove the solvent. Finally, after recrystallization in a 1: 1 mixed solvent of methylene chloride and normal hexane, and filtered under reduced pressure. The obtained solid substance was vacuum dried to obtain 2-cinnamoyl-4,6-dichloro-1,3,5-triazine.

(3) Synthesis of Triazine Monomer Having Two Amine Functions

Next, 29.6 g of 2-cinnamoyl-4,6-dichloro-1,3,5-triazine obtained above was put into a round bottom flask and dissolved in 300 ml of chloroform to obtain a triazine solution. 32.8 g of 4-aminophenol and 12 g of sodium hydroxide were dissolved in 300 ml of distilled water containing 3 g of cetyltrimethylammonium bromide, mixed with the triazine solution, and reacted vigorously for 24 hours. After completion of the reaction, the organic solution phase was separated, transferred to a separatory funnel, washed three times with distilled water to extract impurities, and then water was removed with calcium chloride. The water-removed solution was distilled under reduced pressure to remove chloroform, an organic solvent, and then recrystallized from a mixed solvent of methylene chloride and normal hexane. The precipitated crystals were filtered under reduced pressure and dried in vacuo to obtain a triazine monomer.

(4) Polymerization of Polyamide-Based Polymer Having Cinnamate Functional Group

Next, 44.144 g of the triazine monomer is put in a round bottom flask filled with nitrogen and dissolved in 400 ml of tetrahydrofuran from which moisture is removed. 20.238 g of triethylamine is added to this solution. After dissolving 20.3 g of terephthaloyl chloride in 100 ml of tetrahydrofuran from which water was removed, the mixture was stirred vigorously while slowly dropping into the solution of the previous triazine monomer and triethyl amine and reacted for 12 hours. After completion of the reaction, the reaction solution was slowly poured into methanol, precipitated and filtered, and the precipitate was dried in vacuo. The obtained precipitate was again dissolved in tetrahydrofuran and then precipitated in methanol twice. After vacuum drying, a polyamide-based polymer having a cinnamate functional group was finally synthesized using a triazine ring.

(5) Formation of Overcoat Layer

In the above-mentioned composition of the overcoat layer, 8 g of the polyamide polymer prepared in (4) was mixed based on the weight of 100 g of the composition having no binder mixed therein, and the mixed solution was coated on a substrate and baked at 150 ° C. for 10 minutes. UV (1.5 J / cm ₂ energy density at 365 nm) was investigated. Next, the substrate was refired at 230 ° C. for 1 hour to form an overcoat layer on the substrate.

Example  4 : Maleimide A functional group  Synthesis of Polyamide-Based Polymer Having

The polyamide-based polymer having a maleimide functional group according to Example 4 of the present invention is synthesized by the following process, which corresponds to the case where R ₁ in Chemical Formula 1 or Chemical Formula 2 is Chemical Formula 3d.

(1) Preparation of N-hydroxymaleimide

42.26 g of N- (phenyloxycarbonyloxy) maleimide (II) is dissolved in 500 ml of methanol and refluxed for 3 hours. After the reaction, methanol was evaporated to remove the residue, and the remaining liquid was poured into benzene to obtain a solid. This solid was recrystallized using a mixed solvent of tetrahydrofuran (THF) and hexane to give 12.60 g of N-hydroxymaleimide in a yield of 62%. The crystal melting point was measured at 125 ° C., consistent with the values reported in 125-126 ° C. (Akiyama, M., et al., J. Chem. Soc., Perkin 1 1980, 2122).

(2) Preparation of triazine substituted with maleimide

Next, 11.3 g of the N-hydroxymaleimide was dissolved in 100 ml of tetrahydrofuran (THF). After 3 g of NaH was added thereto, the reaction was carried out for 2 hours, and the reaction solution was slowly added dropwise at -20 ° C to a solution of 18.4 g of triazine dissolved in THF, followed by further reaction for 1 hour after the completion of dropping. Proceeded. After removing the tetrahydrofuran (THF) from the reaction solution, the salt component of the solid phase of the reaction product was removed and recrystallized in a mixed solution of methylene chloride and normal hexane to prepare a triazine compound substituted with maleimide yield 60% 15.7 g was obtained.

(3) Preparation of Triazine Monomer

Next, 26.1 g of the maleimide-substituted triazine compound obtained in the above step was dissolved in 200 ml of chloroform to obtain a triazine solution. 32.8 g of 4-aminophenol and 12 g of sodium hydroxide were dissolved in 300 ml of distilled water in which 3 g of cetyltrimethylammonium bromide was dissolved, mixed with the triazine solution, and reacted vigorously for 24 hours. After completion of the reaction, the organic solution phase was separated, transferred to a separatory funnel, washed three times with distilled water to extract impurities, and then water was removed with calcium chloride. The water-removed solution was distilled under reduced pressure to remove chloroform, an organic solvent, and then recrystallized from a mixed solvent of methylene chloride and normal hexane. The precipitated crystals were filtered under reduced pressure and dried in vacuo to obtain a triazine monomer.

(4) Polymerization of Polyamide-Based Polymer Having Maleimide Functional Group

Next, 40.24 g of the triazine monomer obtained above was put into a round bottom flask filled with nitrogen, dissolved in 400 ml of toluene from which water was removed, and 20.238 g of triethylamine was added thereto. After dissolving 20.3 g of terephthaloyl chloride in 100 ml of toluene, the mixture was stirred vigorously while being slowly added dropwise to the solution of the previous triazine monomer and triethylamine to react for 12 hours. After completion of the reaction, the reaction solution was slowly poured into methanol to precipitate and filtered, and the precipitate was dried in vacuo. The obtained precipitate was again dissolved in tetrahydrofuran and then precipitated in methanol twice. After vacuum drying, a polyamide-based polymer having a maleimide functional group was synthesized using a triazine ring.

(5) Formation of Overcoat Layer

8 g of the polyamide polymer prepared in (4) was mixed on the basis of the weight of 100 g of the composition having no binder mixed in the composition of the overcoat layer mentioned above, and the mixed solution was coated on a substrate and calcined at 230 ° C. for 1 hour. An overcoat layer was formed on the substrate.

On the other hand, the polythioether polymer is represented by the same chemical formula as the polyester polymer and the polyamide polymer described above. That is, it is represented by Formula 1 or Formula 2, R ₁ is also the same. On the other hand, R ₂ , R ₃ , R ₄ , R ₅ are different from polyester-based polymers and polyamides, and are characterized by this. That is, the linkage of R ₂ -R ₄ , R ₃ -R ₄ , R ₃ -R ₅ in Formula 1, and the linkage of R ₂ -R ₄ in Formula 2 are obtained by reaction of thiol and halide, The general form is shown in Scheme 2 below.

Scheme 2

In addition, in Formula 1, R ₂ and R ₃ and, in Formula 2, R ₂ is an alkyl halide or aryl halide of Scheme 2,

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It is selected from the group of substances consisting of, 0≤m≤10, 0≤n≤10, and A and 1 to 8 are each selected from any one of H, F, DN, CF ₃ or CH ₃ .

That is, R ₂ and / or R ₃ unsubstituted or substituted alkyl elements, aryl compounds unsubstituted or substituted with cyan or halogen elements, alicyclic compounds substituted with alkyl or halogenated alkyls, alkyl, One of the aromatic compounds substituted by halogenated alkyl or alkoxyalkyl, wherein the carbon number is 1-30.

In addition, in Formula 1, R ₄ and R ₅ , In Formula 2 R ₄ is a thiol, respectively

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,

It is selected from the group consisting of substances, satisfying the conditions of 0≤m≤10, 0≤n≤10, A and 1 to 8 are each selected from any one of H, F, CN, CF ₃ or CH ₃ .

That is, R ₄ and R ₅ Each is a thiol comprising an alkyl compound which is unsubstituted or substituted with cyan or a halogen element, a thiol comprising an alkoxyalkyl compound which is unsubstituted or substituted with a cyan or halogen element, and an alkyl which is unsubstituted or substituted with a cyan or halogen element A thiol containing an alicyclic compound substituted with a compound, or a thiol containing an aromatic compound substituted with alkyl, halogenated alkyl or alkoxyalkyl, wherein the carbon number is 1-30.

Look at an embodiment of the overcoat layer comprising a polythioether-based polymer as described above.

Example  5: Calcon A functional group  Having Polythioether  Containing polymer Overcoat layer  formation

The polythioether-based polymer having a chalcone (chalcone) functional group according to the present embodiment is synthesized by the following process, which corresponds to the case where R ₁ in Chemical Formula ₁ is Chemical Formula 3b.

(1) Synthesis of Chalcone Photosensitive Functional Group

First, 10 g of 4-methoxychalcone and 2.05 g of sodium cyanide were dissolved in 100 ml of dimethylsulfoxide and reacted for 24 hours. After completion of the reaction, the reaction solution was mixed with chloroform and then stirred with distilled water to extract impurities. Subsequently, the aqueous phase was removed, and the chloroform was removed under reduced pressure at room temperature. The remaining solid phase was recrystallized in methanol, and then dried in vacuo at 40 ° C. to obtain a side chain 4-hydroxychalcone for photoreaction.

(2) Introduction of Chalcone Functional Groups into Triazine Rings

Next, 23.8 g of the 4-hydroxychalcone are placed in a round bottom flask filled with nitrogen and dissolved in 240 ml of tetrahydrofuran from which moisture is removed. 2.4 g of sodium hydroxide (NaOH) was added thereto and reacted at room temperature for 6 hours. 18.4 g of triazine was added to a round-bottomed flask, and the solution was slowly added dropwise at -5C to 200 ml of tetrahydrofuran from which moisture was removed, followed by vigorous stirring for 24 hours. After completion of the reaction, distillation under reduced pressure, tetrahydrofuran was removed, and the obtained solid was dissolved in chloroform again. The solution was washed three times with distilled water in a separatory funnel to extract impurities, and then water was removed with calcium chloride. The solution was distilled under reduced pressure again to remove chloroform, and then recrystallized with a mixed solvent of methylene chloride and normal nucleic acid. The obtained material was filtered under reduced pressure and dried in vacuo to give triazine having a chalcone functional group.

(3) Synthesis of Triazine Monomer Having Two Halide Functional Groups

Next, 38.6 g of triazine having a chalcone functional group obtained as described above was dissolved in 400 ml of chloroform to obtain a triazine solution. 25.6 g of 4-chlorophenol and 8 g of sodium hydroxide were dissolved in 300 ml of distilled water containing 3 g of cetyltrimethylammonium bromide, mixed with the triazine solution, and reacted vigorously for 24 hours. After completion of the reaction, the organic solution phase was separated, transferred to a separatory funnel, washed three times with distilled water to extract impurities, and then water was removed with calcium chloride. The water-removed solution was distilled under reduced pressure to remove chloroform as an organic solvent, and then recrystallized in a mixed solvent of methylene chloride and normal hexane. The precipitated crystals were filtered under reduced pressure and dried in vacuo to give a triazine monomer having two halide functional groups. Got.

(4) Synthesis of Polythioether Polymer Having Chalcone Functional Group

Next, 56.7 g of the triazine monomer having the two halide functional groups obtained above are placed in a round bottom flask and dissolved in 600 ml of nitrobenzene. 14.2 g of 1,4-phenyldithiol, 8 g of sodium hydroxide, and 0.3 g of cetyltrimethylammonium bromide were dissolved in 100 ml of water, mixed with a nitrobenzene solution in which the previous triazine monomer was dissolved, and vigorously stirred to react for 24 hours. The precipitate was poured into methanol slowly, precipitated, filtered, and the precipitate was dried in vacuo. The precipitate thus obtained was again dissolved in tetrahydrofuran and then precipitated in methanol twice, and then vacuum-dried to finally synthesize a polythioether polymer having a chalcone photosensitive functional group using a triazine ring.

(5) Formation of Overcoat Layer

In the above-mentioned composition of the overcoat layer, 8 g of the polyamide polymer prepared in (4) was mixed based on the weight of 100 g of the composition having no binder mixed therein, and the mixed solution was coated on a substrate and baked at 150 ° C. for 10 minutes. UV (1.5 J / cm ₂ energy density at 365 nm) was investigated. Next, the substrate was refired at 230 ° C. for 1 hour to form an overcoat layer on the substrate.

Example 6 Formation of Overcoat Layer Containing Polythioether-Based Polymer Having Coumarin Functional Group

The polythioether polymer having a coumarin functional group according to the present embodiment is synthesized by the following process, which corresponds to the case where R ₁ in Chemical Formula ₁ is Chemical Formula 3c.

(1) Introduction of coumarin functional group

First, 16.2 g of 7-hydroxycoumarin and 2.4 g of sodium hydride (NaH) were placed in a round bottom flask filled with nitrogen, dissolved in 160 ml of tetrahydrofuran from which water was removed, and then stirred vigorously for 6 hours. 18.4 g of triazine was added to the round bottom flask, and the solution was dissolved in 200 ml of tetrahydrofuran from which water was removed. The solution was reacted vigorously with vigorous stirring at −5 ° C. for 24 hours. After completion of the reaction, distillation under reduced pressure to remove tetrahydrofuran and the obtained solid was dissolved in chloroform again. This was washed three times with distilled water in a separatory funnel to extract impurities, followed by removing water with calcium chloride, and distilling under reduced pressure to remove chloroform and recrystallized with a mixed solvent of methylene chloride and normal nucleic acid. The material obtained through the above process was filtered under reduced pressure and then vacuum dried to obtain triazine having a coumarin photosensitive functional group.

(2) Introduction of coumarin photosensitive functional groups to the triazine ring

Next, 31.1 g of the triazine having the coumarin photosensitive functional group was dissolved in 400 ml of chloroform to obtain a triazine solution. After dissolving 25.6 g of 4-chlorophenol and 8 g of sodium hydroxide in 300 ml of distilled water in which 3 g of cetyltrimethylammonium bromide was dissolved, the mixture was mixed with the triazine solution and reacted vigorously for 24 hours. After completion of the reaction, the organic solution phase was separated, transferred to a separatory funnel, washed three times with distilled water to extract impurities, and then water was removed with calcium chloride. The water-removed solution was distilled under reduced pressure to remove chloroform, an organic solvent, and then recrystallized from a mixed solvent of methylene chloride and normal hexane. The precipitated crystals were filtered under reduced pressure and then dried in vacuo to obtain a triazine monomer having two halide functional groups.

(3) Synthesis of Triazine Monomer Having Two Halide Functional Groups

Then, 49.1 g of the triazine monomer having the two halide functional groups were put in a round bottom flask and dissolved in 600 ml of nitrobenzene. 14.2 g of 1,4-phenyldithiol, 8 g of sodium hydroxide, and 0.3 g of cetyltrimethylammonium bromide were dissolved in 100 ml of water, mixed in a nitrobenzene solution in which the triazine monomer was dissolved, and vigorously stirred to react for 24 hours. . After completion of the reaction, the reaction solution was slowly poured into methanol to precipitate and filtered, and the precipitate was dried in vacuo. After vacuum drying, the obtained precipitate was dissolved in tetrahydrofuran again, and then precipitated in methanol was repeated twice, followed by vacuum drying to finally synthesize a polythioether polymer having a coumarin functional group using a triazine ring.

(4) Formation of Overcoat Layer

In the above-mentioned composition of the overcoat layer, 8 g of the polyamide polymer prepared in (3) was mixed on the basis of the weight of 100 g of the composition having no binder mixed therein, and the mixed solution was coated on a substrate and baked at 150 ° C. for 10 minutes. Thereafter, the substrate was refired at 230 ° C. for 1 hour to form an overcoat layer on the substrate.

Experimental Example

In this Experimental Example, the overcoat layer obtained through Examples 1 to 6 and the conventional overcoat layer (comparative example) were measured for the required physical properties of the overcoat layer.

The specific composition of the overcoat layer composition in Examples 1-6 and a comparative example is as Table 1, The physical property measurement result of Examples 1-6 and a comparative example obtained by this is shown in Table 2.

Table 1

Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Comparative example Bar in the Polyester 7.3% 7.3% - - - - - Polyamide - - 7.3% 7.3% - - - Polythioether - - - - 7.3% 7.3% - Polyolefin - - - - - - 7.3% Monomer 5% 5% 5% 5% 5% 5% 5% Hardener 3% 3% 3% 3% 3% 3% 3% Initiator 2% 2% 2% 2% 2% 2% 2% Adhesion promoter One% One% One% One% One% One% One% Inhibitor One% One% One% One% One% One% One% Surfactants One% One% One% One% One% One% One% menstruum Remaining amount Remaining amount Remaining amount Remaining amount Remaining amount Remaining amount Remaining amount

TABLE 2

Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Comparative example fume generation 1.2mg 1.1mg 1.2mg 1.1mg 1.1mg 1.2mg 2mg Thickness change rate -1.4% -1.1% -1.3% -1.1% -1.2% -1.3% -6.1%

As can be seen from Table 2, when looking at the comparative example using a polyolefin-based polymer and Examples 1 to 6 of the present invention, the generation of bubbles (fume) was reduced to about 50%. This means that the possibility of diffusion of the overcoat layer material into the liquid crystal formed over the overcoat layer is only about half of that of the comparative examples in Examples 1 to 6 of the present invention. Therefore, the contamination of the liquid crystal layer is prevented, and thus the display quality can be improved by solving conventional defects such as afterimages and stains.

In addition, the thickness change rate is a measure of the thickness change at the time of forming the overcoat layer and after the progress of the high temperature process, in the case of the comparative example is about 6% thickness reduction after the progress of the high temperature process, Examples 1 to 6 of the present invention is 1.1 There was a thickness reduction of ˜1.4%. That is, the thickness reduction in the Example of this invention is only about 1/6 thru | or 1/5 compared with the conventional comparative example. This shows properties suitable for the purpose of forming an overcoat layer for planarization of the top surface. In particular, when the thickness change of the overcoat layer is large, the liquid crystal material cannot be prevented from leaking and the thickness of the liquid crystal layer cannot be maintained uniformly. In the embodiment of the present invention, the thickness change is about 80% smaller than that of the conventional comparative example. This has the effect of improving the protection of the liquid crystal layer and its thickness uniformity.

Claims (4)

5 to 10% by weight of the polymeric binder having a repeating unit represented by the formula (1), 1 to 5% by weight of the monomer having a polyfunctional group, 1 to 5% by weight of anhydride curing agent, 0.1 to 2% by weight of the initiator, 0.1 to 1% by weight of the inhibitor , 0.1-1% by weight of adhesion promoter, 0.1-1% by weight of surfactant and residual amount of the composition for overcoat layer of liquid crystal display device. Formula 1

In Formula 1, m + n = 1, 0 ≦ m ≦ 1, and 0 ≦ n ≦ 1, wherein R1 is selected from Formulas 2a to 2d, and each of R ₂ and R ₃ has 1 to 30 carbon atoms. Is one of an aliphatic alcohol compound, an alicyclic alcohol compound, or an aromatic alcohol compound, and each of R ₄ and R ₅ is one of carboxylic acid compounds containing an alicyclic or aromatic compound having 1 to 30 carbon atoms.) Formula 2a

Formula 2b

Formula 2c

Formula 2d

(In Formula 2a, X is

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Any one selected from the group consisting of materials (where 0 ≦ m ≦ 10, 0 ≦ n ≦ 10 is satisfied), and in Formula 2b, Y is

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Any one selected from the group of substances consisting of, wherein each of 1 to 9

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Any one selected from the group of substances consisting of (hereinafter referred to as 'Y substance group'), where 0≤m≤10, 0≤n≤10, and A and B are each H, F, CL, CN , CF ₃ or CH ₃ , In Formulas 2c and 2d, 0 ≦ n ≦ 10, and each of 1 to 5 is any one selected from the group Y, and in Formula 2d, Y is

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It is any one selected from the group of substances consisting of 0, and satisfy | fills 0 <= n <= 10, and 1 and 2 are each of H, F, CH3, CF3, CN, cyclopentane, and cyclohexane. 5 to 10% by weight of the polymeric binder having a repeating unit represented by the formula (1), 1 to 5% by weight of the monomer having a polyfunctional group, 1 to 5% by weight of anhydride curing agent, 0.1 to 2% by weight of the initiator, 0.1 to 1% by weight of the inhibitor , 0.1-1% by weight of adhesion promoter, 0.1-1% by weight of surfactant and residual amount of the composition for overcoat layer of liquid crystal display device. Formula 1

In Formula 1, m + n = 1, 0 ≦ m ≦ 1, and 0 ≦ n ≦ 1, wherein R1 is selected from Formulas 2a to 2d, and each of R ₂ and R ₃ has 1 to 30 carbon atoms. Is an amine compound including an alkylamine compound, an alkoxyamine compound, an alkylbenzyl or an alkoxybenzyl compound, each of R ₄ and R ₅ is one of a carboxylic acid compound containing an alicyclic or aromatic compound having 1 to 30 carbon atoms.) Formula 2a

Formula 2b

Formula 2c

Formula 2d

(In Formula 2a, X is

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Any one selected from the group of substances consisting of (where 0≤m≤10, 0≤n≤10 is satisfied), and in Formula 2b Y is

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Any one selected from the group of substances consisting of, wherein each of 1 to 9

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It is any one selected from the group of substances (hereinafter referred to as 'Y substance group'), where 0≤m≤10, 0≤n≤10, and A and B are each H, F, CL, CN , CF ₃ or CH ₃ , In Formulas 2c and 2d, 0 ≦ n ≦ 10, and each of 1 to 5 is any one selected from the group Y, and in Formula 2d, Y is

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Any one selected from the group of substances consisting of, 0≤n≤10, and 1 and 2 are one of H, F, CH3, CF3, CN, cyclopentane, cyclohexane. 5 to 10% by weight of the polymeric binder having a repeating unit represented by the formula (1), 1 to 5% by weight of the monomer having a polyfunctional group, 1 to 5% by weight of anhydride curing agent, 0.1 to 2% by weight of the initiator, 0.1 to 1% by weight of the inhibitor , 0.1-1% by weight of adhesion promoter, 0.1-1% by weight of surfactant and residual amount of the composition for overcoat layer of liquid crystal display device. Formula 1

In Formula 1, m + n = 1, 0 ≦ m ≦ 1, and 0 ≦ n ≦ 1, wherein R1 is selected from Formulas 2a to 2d, and each of R ₂ and R ₃ has 1 to 30 carbon atoms. Unsubstituted or substituted alkyl compounds of halogen, aryl compounds unsubstituted or substituted with cyan or halogen elements, cycloaliphatic compounds substituted with alkyl or halogenated alkyls, substituted with alkyl, halogenated alkyl or alkoxyalkyls; One of the aromatic compounds, each of R ₄ and R ₅ represents a thiol comprising an alkyl compound of 1 to 30 carbon atoms which is unsubstituted or substituted with cyan or a halogen, and an alkoxyalkyl compound which is unsubstituted or substituted with cyan or a halogen Thiols, including thiols, including cycloaliphatic compounds, which are unsubstituted or substituted with alkyl compounds substituted with cyan or halogen, or substituted with alkyl, halogenated alkyl or alkoxyalkyl. Group is one of the thiol-containing compound.) Formula 2a

Formula 2b

Formula 2c

Formula 2d

(In Formula 2a, X is

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Any one selected from the group consisting of materials (where 0 ≦ m ≦ 10, 0 ≦ n ≦ 10 is satisfied), and in Formula 2b, Y is

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Any one selected from the group of substances consisting of, wherein each of 1 to 9

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Any one selected from the group of substances consisting of (hereinafter referred to as 'Y substance group'), where 0≤m≤10, 0≤n≤10, and A and B are each H, F, CL, CN , CF ₃ or CH ₃ , In Formulas 2c and 2d, 0 ≦ n ≦ 10, and each of 1 to 5 is any one selected from the group Y, and in Formula 2d, Y is

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It is any one selected from the group of substances consisting of 0, and satisfy | fills 0 <= n <= 10, and 1 and 2 are each of H, F, CH3, CF3, CN, cyclopentane, and cyclohexane. The method according to any one of claims 1 to 3, The initiator comprises a photocuring agent and a thermosetting agent, the relative ratio is 1: 2 composition for the overcoat layer of the liquid crystal display device.