KR20220121495A - A black photo sensitive resin composition, an organic light emitting diode prepared by using the composition, and a display device comprising the organic light emitting diode - Google Patents

Abstract

The present invention relates to a black photosensitive resin composition, a pixel defining layer manufactured using the same, an organic light-emitting device comprising the pixel defining layer, and a display device comprising the organic light-emitting device. The black photosensitive resin composition according to the present invention comprises a colorant, a photopolymerizable compound, an alkali-soluble resin, a photopolymerization initiator and a solvent, wherein the photopolymerizable compound includes a dendrimer acrylate oligomer having an acrylate functionality of 15 or greater.

Description

A black photosensitive resin composition, an organic light emitting device manufactured using the same, and a display device including the organic light emitting device TECHNICAL FIELD EMITTING DIODE}

The present invention relates to a black photosensitive resin composition, a pixel defining layer manufactured using the same, an organic light emitting device including the pixel defining layer, and a display device including the organic light emitting device.

Since an organic light emitting diode, which is one of flat panel display devices, is a self-emissive type, it has superior viewing angle and contrast compared to a liquid crystal display device, and a backlight. Because back light is not required, it is lightweight and thin, and it is advantageous in terms of power consumption. In addition, DC low voltage driving is possible, the response speed is fast, and since all components are solid, it is strong against external shocks, has a wide operating temperature range, and is inexpensive in terms of manufacturing cost. In particular, in the manufacturing process of the organic light emitting device, unlike a liquid crystal display device or a plasma display panel (PDP), it can be said that repetition of the deposition/etching process and the encapsulation process are all of the process. It has the advantage of being very simple.

The organic light emitting device should have good contrast and luminance, but when external light is bright, the contrast is not good. In particular, in the case of a bottom emission type organic light emitting device, since the cathode of the device is made of a metal having excellent reflectivity, light entering the device from the outside is reflected on the cathode surface and mixed with the light emitted from the light emitting layer. In order to solve this problem, most organic light emitting devices currently reduce the reflection of external incident light by the cathode by forming a circular polarizer under the transparent substrate. That is, when light is incident from the outside, half is blocked by the circularly polarizing plate, and the other half that is not blocked is blocked when reflected on the cathode surface, thereby suppressing a decrease in contrast caused by external light.

However, the organic light emitting device having a circularly polarizing plate attached to the above-described conventional transparent substrate greatly reduces the reflection of external incident light by the cathode and at the same time blocks even the light emitted from the organic light emitting layer to the outside, so the contrast is improved but the luminance is 50% There was a problem in that the above was reduced, and high cost was caused by the introduction of the circularly polarizing plate.

In order to solve the above problem, a black pixel defined layer that absorbs external incident light to improve contrast may be formed. The black pixel-defining layer is precisely patterned through a photolithography process, and then subjected to a high-pressure deposition process for manufacturing an organic light-emitting device pixel. However, in the conventional liquid crystal display device (liquid crystal display device), the photosensitive resin composition for BM (Black Matrix) releases a gas component fatal to driving the organic light emitting device during the high-pressure deposition process of manufacturing the organic light emitting device pixel, thereby reducing the luminance. In severe cases, there is a problem in that driving of the organic light emitting device becomes impossible.

In relation to this, Korean Patent Registration No. 10-0814660 discloses a black photosensitive resin composition containing an acrylic compound, but it seems that the outgas characteristics in the high-pressure deposition process are not sufficient. Accordingly, in manufacturing an organic light emitting display device, a new black photosensitive resin composition capable of manufacturing an organic light emitting display device having excellent contrast and luminance while minimizing the elution of outgas components fatal to driving the organic light emitting device during the high-pressure deposition process. development is required.

Republic of Korea Patent Registration No. 10-0814660

The present invention, as devised to solve the problems of the prior art, is a black photosensitive resin composition having excellent reliability with little elution of gas components fatal to device driving even when a high-pressure deposition process for manufacturing an organic light-emitting device pixel is performed aims to provide

Another object of the present invention is to provide a pixel defining layer made of the black photosensitive resin composition, an organic light emitting device including the pixel defining layer, and a display device including the organic light emitting device.

However, the problem to be solved by the present application is not limited to the problems mentioned above, and other problems not mentioned will be clearly understood by those skilled in the art from the following description.

In order to achieve the above object, the present invention comprises a colorant, a photopolymerizable compound, an alkali-soluble resin, a photoinitiator and a solvent, wherein the photopolymerizable compound comprises a dendrimer acrylate oligomer having a function of 15 or more, black photosensitivity A resin composition is provided.

In addition, the present invention provides a pixel defining film made of the black photosensitive resin composition of the present invention.

In addition, the present invention provides an organic light emitting device including the pixel defining layer of the present invention.

In addition, the present invention provides a display device including the organic light emitting device of the present invention.

The black photosensitive resin composition of the present invention can effectively prevent the limitation of exposure transmittance caused by the black pigment included to impart light-shielding properties interfering with photosensitivity and thus not efficiently photocrosslinking, and disadvantages in the development process caused by this. It is possible to provide a pixel defining layer with

In particular, it is possible to provide a pixel-defining film capable of preventing color mixing of each pixel and effectively preventing external light reflection since it exhibits an excellent effect of outgas generation characteristics in a high-pressure deposition process for manufacturing an organic light-emitting device pixel. In addition, the black photosensitive resin composition of the present invention can minimize the change in film thickness before and after post-baking, and can produce a film excellent in pencil hardness, adhesion, and chemical resistance (reliability and developability).

Therefore, the black photosensitive resin composition of the present invention can be usefully used for manufacturing an organic light emitting device.

The present invention relates to a black photosensitive resin composition comprising a colorant, a photopolymerizable compound, an alkali-soluble resin, a photopolymerization initiator, and a solvent, wherein the photopolymerizable compound comprises a 15 or more functional dendrimer acrylate oligomer.

In addition, the present invention relates to a pixel defining film made of the black photosensitive resin composition, an organic light emitting device including the pixel defining layer, and a display device including the organic light emitting device.

The black photosensitive resin composition of the present invention can effectively prevent the limit of exposure transmittance caused by the black pigment included to impart light-shielding properties interfering with photosensitivity and thus not efficiently photocrosslinking, and disadvantages in the development process due to this. It is possible to provide a pixel defining layer capable of

In particular, it is possible to provide a pixel-defining film capable of preventing color mixing of each pixel and effectively preventing external light reflection because it exhibits an excellent effect of generating outgas in a high-pressure deposition process for manufacturing an organic light-emitting device pixel.

In addition, the black photosensitive resin composition of the present invention can minimize the change in film thickness before and after post-baking, and can produce a film excellent in pencil hardness, adhesion and chemical resistance.

<Black photosensitive resin composition>

The black photosensitive resin composition of the present invention is characterized in that it contains a photopolymerizable compound having a functional group in a specific range, and specifically may include a colorant, a photopolymerizable compound, an alkali-soluble resin, and a photoinitiator, and a solvent and may further include additives as necessary.

coloring agent

The colorant used in the present invention may include at least one selected from the group consisting of a black pigment or dye, and an organic pigment or dye. The black photosensitive resin composition of this invention can provide light-shielding property by including a black pigment.

The colorant used in the present invention may be black itself, such as a black pigment or dye, or a case in which black can be obtained by mixing several pigments or dyes is included. The colorant is not particularly limited as long as it has light-shielding properties in visible light.

As the black pigment, a known black pigment may be used without particular limitation, and specifically, aniline black, lactam black, perylene black, carbon black, chromium oxide, iron oxide and titanium black may be used, and these may be used alone or in two types. A combination of the above may be used. Channel black, furnace black, thermal black, lamp black, etc. are mentioned as said carbon black.

If necessary, carbon black coated with a resin on the surface may be used for electrical insulation. Since the resin-coated carbon black has lower conductivity than the non-resin-coated carbon black, there is an advantage in that excellent electrical insulation can be imparted when forming a black matrix or a pixel defining film.

The content of the black pigment or dye used as the colorant and the organic pigment or dye may be adjusted to suit the characteristics required for the pixel defining layer. The colorant may be included in an amount of 1 to 50% by weight, preferably 5 to 40% by weight, based on the total weight of the black photosensitive resin composition. If the content of the colorant is less than the above range, light blocking properties are not sufficient, and if it exceeds the above range, there is a risk that the quality of the pattern obtained after patterning may be deteriorated.

photopolymerizable compound

The photopolymerizable compound in the present invention is a compound that can be polymerized by the action of a photopolymerization initiator to be described later, and is characterized by using a photopolymerizable compound including an acrylate oligomer having a functional group in a specific range.

The photopolymerizable compound of the present invention may include an acrylate oligomer having a function of 4 or more to 8 functional or less, and a dendrimer acrylate oligomer having 15 or more functions.

In addition, in the present invention, the photopolymerizable compound may include an acrylate oligomer of tetrafunctional or more to 8 functional or less, and preferably, an acrylate oligomer of 5 to 6 functional or 8 functional acrylate oligomer. have. By including the acrylate oligomer having the above 4-functionality to 8-functionality or less, it is possible to obtain an effect of facilitating the formation of a forward taper pattern in the post-baking step.

The type of the acrylate oligomer having a function of 4 or more to 8 functional or less is not particularly limited, and for example, trimethylolpropane tri(meth)acrylate, ethoxylated trimethylolpropane tri(meth)acrylate, propoxyl Rated trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol tri (meth) acrylate, dipentaerythritol penta (meth) acrylate, Ethoxylated dipentaerythritol hexa(meth)acrylate, propoxylated dipentaerythritol hexa(meth)acrylate, dipentaerythritol hexa(meth)acrylate, etc. are mentioned.

The 15 functional or more dendrimer acrylate oligomer may preferably have 15 functional or more and less than 25 functional, more preferably 15 or more and 20 functional or less, and most preferably 18 or more and 20 functional or less. By including the 15 functional or more dendrimer acrylate oligomer, the hardness of the coating film is improved, and the effect that the remaining film rate is increased can be obtained.

As said 15 functional or more dendrimer acrylate oligomer, Miwon Corporation SP-1106, KPX Greenchem KOMERATE PM900, Shin-Nakamura U-15HA, etc. are mentioned, for example.

Based on the total weight of the photopolymerizable compound, 30 to 90% by weight, preferably 50 to 80% by weight of the tetrafunctional or more and less than 8 functional acrylate monomer; and 10 to 50 wt%, preferably 20 to 50 wt% of the 15 or more functional dendrimer acrylate oligomer. When the content range is satisfied, there is an advantage in that hardness is improved while maintaining the same pattern as before.

In addition, in the present invention, the photopolymerizable compound may further include an acrylate oligomer of 8 functional or more and less than 15 functional, preferably 8 functional or more and 10 functional or less, in order to improve hardness.

As said 8 functional or more and less than 15 functional acrylate oligomer, Osaka Organic Chemical Viscoat #802, Viscoat #1000, Miwon Corporation SC-2153 etc. are mentioned, for example.

The photopolymerizable compound may be used in an amount of 10 to 70 wt%, preferably 20 to 60 wt%, based on the total weight of the black photosensitive resin composition. When the photopolymerizable compound is included in the above range, there is a desirable advantage in terms of strength or smoothness of the pixel portion.

Alkali Soluble Resin

The alkali-soluble resin generally has reactivity and alkali solubility under the action of light or heat, and acts as a dispersion medium for the colorant. It is preferable to use a cardo-based resin as the alkali-soluble resin of the present invention. When the cardo-based binder resin is included, there is an advantage in that reliability between processes is improved. In addition, there is an advantage of providing excellent reliability without generating wrinkles or cracks during the deposition process by minimizing the generation of outgas.

The weight average molecular weight of the cardo-based resin is preferably 5,000 to 10,000, more preferably 5,200 to 9,000. When the above range is satisfied, the hardness of the coating film is improved, and there is an advantage in that the residual film rate is increased.

The acid value of the cardo-based resin is preferably 50 to 120 mgKOH/g, more preferably 70 to 110 mgKOH/g. When the above range is satisfied, there is an advantage in that the solubility of the developer is sufficient, the generation of residues is suppressed, and the pattern formation is easy.

The cardo-based resin is specifically bis (4-hydroxyphenyl) sulfone, bis (4-hydroxy-3,5-dimethylphenyl) sulfone and bis (4-hydroxy-3,5-dichlorophenyl) sulfone, bis (4-hydroxyphenyl)hexafluoropropane, bis(4-hydroxy-3,5-dimethylphenyl)hexafluoropropane and bis(4-hydroxy-3,5-dichlorophenyl)hexafluoropropane; Bis(4-hydroxyphenyl)dimethylsilane, bis(4-hydroxy-3,5-dimethylphenyl)dimethylsilane and bis(4-hydroxy-3,5-dichlorophenyl)dimethylsilane, bis(4-hydroxy hydroxyphenyl)methane, bis(4-hydroxy-3,5-dichloroethyl)methane and bis(4-hydroxy-3,5-dibromophenyl)methane, 2,2-bis(4-hydroxyphenyl) ) propane, 2,2-bis (4-hydroxy-3,5-dimethylphenyl) propane, 2,2-bis (4-hydroxy-3,5-dichlorophenyl) propane, 2,2-bis (4 -Hydroxy-3-methylphenyl)propane and 2,2-bis(4-hydroxy-3-chlorophenyl)propane, bis(4-hydroxyphenyl)ether, bis(4-hydroxy-3,5-dimethyl Phenyl)ether and bis(4-hydroxy-3,5-dichlorophenyl)ether, 9,9-bis(4-hydroxyphenyl)fluorene, 9,9-bis(4-hydroxy-3-methylphenyl) ) fluorene, 9,9-bis (4-hydroxy-3-chlorophenyl) fluorene, 9,9-bis (4-hydroxy-3-bromophenyl) fluorene, 9,9-bis (4 -Hydroxy-3-fluorophenyl) fluorene, 9,9-bis (4-hydroxy-3-methoxyphenyl) fluorene, 9,9-bis (4-hydroxy-3,5-dimethylphenyl) ) obtained from fluorene, 9,9-bis(4-hydroxy-3,5-dichlorophenyl)fluorene and 9,9-bis(4-hydroxy-3,5-dibromophenyl)fluorene, etc. may be, but is not limited thereto.

The alkali-soluble resin may be included in an amount of 1 to 50% by weight, preferably 5 to 40% by weight, based on the total weight of the black photosensitive resin composition. This content range is selected by considering solubility in the developer and pattern formation from various angles. When the alkali-soluble resin is included in the above range, the solubility in the developer is sufficient to facilitate pattern formation, and the pixel portion of the exposed part during development. film reduction is prevented, and the omission property of the non-pixel portion is improved.

photopolymerization initiator

As the photopolymerization initiator, a photopolymerization initiator generally used in the black photosensitive resin composition may be used. For example, acetophenone-based, benzophenone-based, triazine-based, thioxanthone-based, oxime-based, benzoin-based, biimidazole-based compounds and the like may be used.

The acetophenone compound is diethoxyacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, benzyldimethyl ketal, 2-hydroxy-1-[4-(2-hydroxyethoxy) Phenyl]-2-methylpropan-1-one, 1-hydroxycyclohexylphenyl ketone, 2-methyl-1-(4-methylthiophenyl)-2-morpholinopropan-1-one, 2-benzyl- oligomers of 2-dimethylamino-1-(4-morpholinophenyl)butan-1-one and 2-hydroxy-2-methyl[4-(1-methylvinyl)phenyl]propan-1-one are possible and 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)butan-1-one among them.

Benzophenone-based compounds include benzophenone, benzoyl benzoic acid, methyl benzoyl benzoate, 4-phenyl benzophenone, hydroxybenzophenone, acrylated benzophenone, 4,4'-bis(dimethyl amino)benzophenone, 4,4'-bis (diethyl amino) benzophenone and the like are possible.

Examples of the triazine-based compound include 2,4,6-trichloro-s-triazine, 2-phenyl-4,6-bis(trichloromethyl)-s-triazine, 2-(3′,4′-dimethoxy styryl)-4,6-bis(trichloromethyl)-s-triazine, 2-(4'-methoxy naphthyl)-4,6-bis(trichloromethyl)-s-triazine, 2- (p-methoxyphenyl)-4,6-bis(trichloromethyl)-s-triazine, 2-(p-triyl)-4,6-bis(trichloromethyl)-s-triazine, 2- Biphenyl-4,6-bis(trichloromethyl)-s-triazine, bis(trichloromethyl)-6-styryl-s-triazine, 2-(naphtho 1-yl)-4,6- Bis(trichloromethyl)-s-triazine, 2-(4-methoxynaphtho 1-yl)-4,6-bis(trichloromethyl)-s-triazine, 2,4-trichloromethyl ( piperonyl)-6-triazine, 2,4-trichloromethyl(4'-methoxy styryl)-6-triazine, and the like are possible.

The thioxanthone-based compound may include 2-isopropylthioxanthone, 2,4-diethylthioxanthone, 2,4-dichlorothioxanthone, 1-chloro-4-propoxythioxanthone, and the like.

Examples of the oxime-based compound include o-ethoxycarbonyl-α-oxyimino-1-phenylpropan-1-one, and commercial products include OXE-01 and OXE-02 from Ciba and Irgacure OXE03 from Basf. .

As the benzoin-based compound, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether, benzyldimethyl ketal, and the like can be used.

Examples of the biimidazole-based compound include 2,2′-bis(2-chlorophenyl)-4,4′,5,5′-tetraphenylbiimidazole, 2,2′-bis(2,3-dichlorophenyl) -4,4',5,5'-tetraphenylbiimidazole, 2,2'-bis(2-chlorophenyl)-4,4',5,5'-tetra(alkoxyphenyl)biimidazole, 2 ,2′-bis(2-chlorophenyl)-4,4′,5,5′-tetra(trialkoxyphenyl)biimidazole, the phenyl group at the 4,4′,5,5′ position is replaced by a carboalkoxy group Substituted imidazole compounds and the like are possible.

The photopolymerization initiator may be included in an amount of 0.1 to 10% by weight, preferably 0.3 to 8% by weight, based on the total weight of the black photosensitive resin composition. This content range is in consideration of the photopolymerization rate of the photopolymerizable compound and the physical properties of the finally obtained coating film. If the content is less than the above range, the polymerization rate is low and the overall process time may be prolonged. Since the physical properties of the coating film may be rather deteriorated over time, it is necessary to appropriately use it within the above range.

In addition, a photopolymerization initiation auxiliary may be used together with the photopolymerization initiator. When the photopolymerization initiation auxiliary is used together with the photopolymerization initiator, the photosensitive resin composition becomes more sensitive and productivity is improved. At least one compound selected from the group consisting of amines and carboxylic acid compounds may be preferably used as the photopolymerization initiation adjuvant.

Such a photopolymerization initiation adjuvant is generally 10 mol or less per 1 mol of the photopolymerization initiator, and preferably used within the range of 0.01 to 5 mol. When the photopolymerization initiation auxiliary agent is used within the above range, the effect of improving the productivity can be expected by increasing the polymerization efficiency.

solvent

In the present invention, as long as the solvent is effective in dissolving other components included in the black photosensitive resin composition but does not react, the solvent used in the general black photosensitive resin composition may be used without particular limitation.

Specific examples of the solvent include ethylene glycol monoalkyl ethers such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, and ethylene glycol monobutyl ether; diethylene glycol dialkyl ethers such as diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol dipropyl ether, and diethylene glycol dibutyl ether; ethylene glycol alkyl ether acetates such as methyl cellosolve acetate and ethyl cellosolve acetate; alkylene glycol alkyl ether acetates such as propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol monopropyl ether acetate, methoxybutyl acetate and methoxypentyl acetate; aromatic hydrocarbons such as benzene, toluene, xylene, and mesitylene; ketones such as methyl ethyl ketone, acetone, methyl amyl ketone, methyl isobutyl ketone and cyclohexanone; alcohols such as ethanol, propanol, butanol, hexanol, cyclohexanol, ethylene glycol, and glycerin; esters such as ethyl 3-ethoxypropionate and methyl 3-methoxypropionate; and cyclic esters such as γ-butyrolactone.

Among the above solvents, from the viewpoint of applicability and dryness, an organic solvent having a boiling point of 100°C to 200°C may be preferably used in the solvent, and more preferably alkylene glycol alkyl ether acetates, ketones, 3-ethoxy Esters such as ethyl propionate and methyl 3-methoxypropionate can be used, and more preferably, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, cyclohexanone, 3-ethoxy ethyl propionate, 3- methyl methoxypropionate and the like can be used. These solvents can be used individually or in mixture of 2 or more types, respectively.

The solvent may be included in an amount of usually 30 to 80% by weight, preferably 40 to 70% by weight, based on the total weight of the black photosensitive resin composition. When the solvent is included in the above range, the coating property tends to be good when applied with an application device such as a roll coater, a spin coater, a slit and spin coater, a slit coater (sometimes referred to as a die coater) and an inkjet, so it is preferable do.

additive

The black photosensitive resin composition of the present invention may further include additives according to the needs of those skilled in the art in a range that does not impair the purpose of the present invention in addition to the above components, and the additives may include adhesion promoters, surfactants, etc. , but is not limited thereto.

The adhesion promoter may be added to increase adhesion to the substrate, and may include a silane coupling agent having a reactive substituent selected from the group consisting of a carboxyl group, a methacryloyl group, an isocyanate group, an epoxy group, and combinations thereof. However, the present invention is not limited thereto. For example, the silane coupling agent is trimethoxysilyl benzoic acid, γ-methacryl oxypropyl trimethoxy silane, vinyltriacetoxysilane, vinyl trimethoxysilane, γ-isocyanate propyl triethoxysilane, γ-glycidoxy and propyl trimethoxysilane and β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, and these may be used alone or in combination of two or more.

The surfactant can be used to further improve the coatability of the black photosensitive resin composition, BM-1000, BM-1100 (BM Chemie), Proride FC-135/FC-170C/FC-430 (Sumitomo 3M Co., Ltd.) ), SH-28PA/-190/SZ-6032 (Toray Silicon Co., Ltd.), etc., may be used, but the present invention is not limited thereto. The surfactant may be used as a pigment dispersant, and in this case, a polyester-based surfactant may be used.

The additive may be included in an amount of 0.1 to 5% by weight, preferably 0.5 to 3% by weight, based on the total weight of the black photosensitive resin composition.

< Pixel defining film, organic light emitting device and display device >

In addition, the present invention provides a pixel defining layer manufactured using the black photosensitive resin composition, an organic light emitting device including the pixel defining layer, and a display device including the organic light emitting device.

In one embodiment of the present invention, the black photosensitive resin composition may be used for forming a pixel defining layer of an organic light emitting device, or the black photosensitive resin composition may be used for a black bank or a light blocking layer. In other words, in the present invention, the “pixel defining layer” may be used interchangeably with “black bank” or “light blocking layer”.

In general, when an organic light emitting diode is driven, especially in a mobile device used outdoors, scattering by light reduces visibility. When a separate black matrix is introduced for absorption of the scattered light, visibility in the outdoors can be improved, but since a process for introducing the black matrix must be added, the process becomes complicated, and the cost and time increase, so that the efficiency of the process is ultimately reduced. may be lowered.

Since the pixel defining film manufactured using the black photosensitive resin composition according to the present invention can serve not only as a black bank of the organic light emitting device but also as a black matrix, light scattering of the organic light emitting device without additional process There is an advantage in that visibility can be improved.

In one embodiment, the pixel defining layer may be manufactured by a photolithography method, and a typical patterning process for forming the pixel defining layer according to the photolithography method includes the following steps:

a) applying a black photosensitive resin composition to the substrate;

b) a prebaking step of drying the solvent;

c) applying a photomask on the obtained film and irradiating actinic light to cure the exposed portion;

d) performing a developing process for dissolving the unexposed portion using an aqueous alkali solution; and

e) performing drying and post-baking.

The coating may be performed by a wet coating method using an application device such as a roll coater, a spin coater, a slit and spin coater, a slit coater (sometimes referred to as a die coater), or an inkjet to obtain a desired thickness.

Prebaking is performed by heating with an oven, a hot plate, etc. At this time, the heating temperature and heating time in the prebaking are appropriately selected according to the solvent to be used, and are performed at a temperature of, for example, 80 to 150 for 1 to 30 minutes.

In addition, exposure performed after prebaking is performed by an exposure machine, and only the part corresponding to a pattern is exposed by exposing through a photomask. In this case, the irradiated light may be, for example, visible light, ultraviolet light, X-ray, electron beam, or the like.

Alkali development after exposure It is performed for the purpose of removing the photosensitive resin composition of the part which is not removed of a non-exposed part, and a desired pattern is formed by this development. As a developing solution suitable for this alkali development, the aqueous solution of the carbonate of an alkali metal or alkaline-earth metal, etc. can be used, for example. In particular, using an aqueous alkali solution containing less than 1 to 3 wt% of carbonates such as sodium carbonate, potassium carbonate, lithium carbonate, etc., at a temperature of 10 to 50 ° C, preferably 20 to 40 ° C, using a developer or ultrasonic cleaner, etc. carry out

Post-baking is performed to increase the adhesion between the patterned film and the substrate, and is performed through heat treatment at 80-220° C. for 10 to 120 minutes. Post-bake As with pre-bake, it is performed using an oven, a hot plate, or the like.

In addition, the pixel defining film made of the black photosensitive resin composition of the present invention has excellent physical properties such as optical density, adhesion, electrical insulation, and light-shielding property, as well as excellent heat resistance and solvent resistance, such as an organic light emitting device, and the organic light emitting device It is possible to improve the reliability of the display device including the.

Hereinafter, the present invention will be described in more detail through examples. However, the following examples are for explaining the present invention in more detail, and the scope of the present invention is not limited by the following examples. The following examples can be appropriately modified and changed by those skilled in the art within the scope of the present invention. In the following Examples and Comparative Examples, "%" and "part" indicating the content are by weight unless otherwise specified.

Synthesis Example 1: Synthesis of alkali-soluble resin 1 (binder 1)

In a four-neck flask, 235 g (epoxy equivalent 235) of a bisphenol fluorene type epoxy monomer represented by the following formula (1), 110 mg of tetramethylammonium chloride, 100 mg of 2,6-di-tertbutyl-4-methylphenol, and 72.0 g of acrylic acid was dissolved by heating from 90° C. to 100° C. while blowing air at a rate of 25 ml/min.

[Formula 1]

Next, while the solution was in a cloudy state, the temperature was slowly raised to 120° C. to completely dissolve it. At this time, stirring was continued while confirming that the solution gradually became transparent. Heating and stirring was continued for about 12 hours until the acid value became less than 1.0 mgK0H/g. Then, it cooled to room temperature, and the bisphenol fluorene type epoxy acrylate represented by the following formula (2) which is colorless and transparent and solid was obtained.

[Formula 2]

Thereafter, 600 g of propylene glycol monoethyl ether acetate (PGMEA) was added and dissolved in 307.0 g of the bisphenol fluorene type epoxy acrylate thus obtained, followed by 80.5 g of benzophenone tetracarboxylic dianhydride and 1 g of tetraethylammonium bromide. It was mixed and made to react at 110 degreeC to 115 degreeC for 4 hours. After confirming the disappearance of the acid anhydride group, 38.0 g of 1,2,3,6-tetrahydrophthalic anhydride was mixed and reacted at 90° C. for 7 hours to obtain a cardo-based binder resin.

At this time, the disappearance of the acid anhydride group was confirmed by the IR spectrum. It was confirmed that the prepared cardo-based binder resin had a weight average molecular weight of 5,300 g/mol and an acid value of 101 mgKOH/g.

Synthesis Example 2: Synthesis 2 of alkali-soluble resin (binder 2)

69.3 g of benzophenone tetracarboxylic dianhydride and 1 g of tetraethylammonium bromide were mixed, and reacted at 110° C. to 115° C. for 6 hours, and 36.4 g of 1,2,3,6-tetrahydrophthalic anhydride were mixed, Synthesis was carried out in the same manner as in Synthesis Example 1, except for reacting at 90° C. for 4 hours.

It was confirmed that the prepared cardo-based binder resin had a weight average molecular weight of 3,200 g/mol and an acid value of 102 mgKOH/g.

Synthesis Example 3: Synthesis 3 of alkali-soluble resin (binder 3)

A flask equipped with a stirrer, a thermometer reflux cooling tube, a dropping funnel and a nitrogen introduction tube is prepared, while 45 parts of N-benzylmaleimide, 45 parts of methacrylic acid, 10 parts of tricyclodecyl methacrylate, and t-butylper After adding 4 parts of oxy-2-ethylhexanoate and 40 parts of propylene glycol monomethyl ether acetate (hereinafter referred to as "PGMEA"), stirring and mixing to prepare a monomer dropping lot, 6 parts of n-dodecanthiol, PGMEA 24 parts were added, stirred and mixed, and a chain transfer agent dropping lot was prepared.

Thereafter, 395 parts of PGMEA was introduced into the flask, the atmosphere in the flask was changed from air to nitrogen, and the temperature of the flask was raised to 90° C. while stirring. Then, the monomer and the chain transfer agent were started dripping from the dropping lot. The dropping proceeds for 2 h while maintaining 90 ° C, and after 1 h, the temperature is raised to 110 ° C and maintained for 3 h, and then a gas introduction tube is introduced to bubbling the oxygen/nitrogen = 5/95 (v/v) mixed gas. started

Then, 10 parts of glycidyl methacrylate, 0.4 parts of 2,2'-methylenebis(4-methyl-6-t-butylphenol), and 0.8 parts of triethylamine were put into the flask, and the reaction was continued at 110°C for 2 hours. Then, while cooling to room temperature, an acrylic binder resin (binder 3) having a solid content of 29.1% by weight, a weight average molecular weight of 5,900 and an acid value of 114 mgKOH/g was obtained.

Examples 1 to 9 and Comparative Examples 1 to 6: Preparation of black photosensitive resin composition

Black photosensitive resin compositions of Examples 1 to 9 and Comparative Examples 1 to 6 were prepared with the compositions and contents shown in Tables 1 and 2 below.

Composition (wt%) Example One 2 3 4 5 6 7 8 9 coloring agent organic pigment 23.3 23.3 23.3 23.3 23.3 23.3 23.3 23.3 23.3 photopolymerizable compound Photopolymer 1 7.5 Photopolymer 2 13.5 11.5 9 13.5 13.5 10 10 20.5 Photopolymer 3 4.5 11.5 Photopolymer 4 7.5 Photopolymer 5 9 11 9 Photopolymer 6 9 11 5 5 2 Photopolymer 7 9 Photopolymer 8 Alkali-soluble resin binder 1 5.4 5.4 5.4 5.4 5.4 5.4 5.4 5.4 5.4 binder 2 Binder 3 photopolymerization initiator 0.4 0.4 0.4 0.4 0.4 0.4 0.4 0.4 0.4 additive 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 solvent 48.1 48.1 48.1 48.1 48.1 48.1 48.1 48.1 48.1

Composition (wt%) comparative example One 2 3 4 5 6 coloring agent organic pigment 23.3 23.3 23.3 23.3 23.3 23.3 photopolymerizable compound Photopolymer 1 9 Photopolymer 2 22.5 9 13.5 13.5 13.5 13.5 Photopolymer 3 Photopolymer 4 13.5 Photopolymer 5 9 9 Photopolymer 6 Photopolymer 7 Photopolymer 8 9 Alkali-soluble resin binder 1 5.4 5.4 5.4 5.4 binder 2 5.4 Binder 3 5.4 photopolymerization initiator 0.4 0.4 0.4 0.4 0.4 0.4 additive 0.3 0.3 0.3 0.3 0.3 0.3 solvent 48.1 48.1 48.1 48.1 48.1 48.1

Colorant (organic pigment): OBP product

Photopolymerizable compound (photopolymer 1): trifunctional PETA (Pentaerythritol triacrylate)

Photopolymerizable compound (photopolymer 2): 5, 6 functional DPHA (dipentaerythritol hexaacrylate)

Photopolymerizable compound (photopolymer 3): 8 functional V#802

Photopolymerizable compound (photopolymer 4): 14 functional V#1000

Photopolymerizable compound (photopolymer 5): 15 functional U-15HA

Photopolymerizable compound (photopolymer 6): 18 functional SP-1106

Photopolymerizable compound (photopolymer 7): 20 functional KOMERATE PM900

Photopolymerizable compound (photopolymer 8): 25 functional KOMERATE PM905

Alkali-soluble resin (Binder 1): Cardo-based binder resin of Synthesis Example 1 (weight average molecular weight 5,300 g/mol, acid value 101 mgKOH/g)

Alkali-soluble resin (Binder 2): Cardo-based binder resin of Synthesis Example 2 (weight average molecular weight 3,200 g/mol, acid value 102 mgKOH/g)

Alkali-soluble resin (binder 3): acrylic binder resin of Synthesis Example 3 (weight average molecular weight 5,900, acid value 114 mgKOH/g)

Photoinitiator: Irgacure 0XE01

Additive: SH-28PA

Solvent: propylene glycol monomethyl ether acetate

Experimental example

(1) Production of colored substrates

A 5 cm X 5 cm glass substrate (Corning) was washed with a neutral detergent and water, and then dried. Each of the black photosensitive resin compositions prepared in Examples and Comparative Examples was spin-coated on the glass substrate to have a final film thickness of 1.5 μm, pre-baked at 80 to 120° C., and dried for 1 to 2 minutes to remove the solvent. did. Then, by exposing at an exposure amount of 40 to 100 mJ/cm ² , a 1cm X 3cm pattern was formed, and the unexposed portion was removed using an aqueous alkali solution. Then, post-baking was performed at 230° C. for 20 minutes to prepare a colored substrate.

(2) Outgas characteristics evaluation

The outgas evaluation was performed by analyzing the collected compounds by Py-GC/MS while thermally decomposing the colored substrate prepared above at 230° C. for 30 minutes. The analysis results are shown in Table 3 below.

(3) Remaining film rate: change in film thickness before/after PoB

After the pattern formation in (1), the thickness change by the post-baking process at 230°C was confirmed by Equation 1 below. Specifically, when heat of 230° C. was applied for 20 minutes, the thickness before and after the heat was measured, and the change rate (remaining film rate) was calculated by Equation 1 below. The evaluation results are shown in Table 3 below.

[Equation 1]

Remaining film ratio = {(film thickness after heat treatment) / (film thickness before heat treatment)} × 100 (%)

(4) Surface hardness

The degree of curing of the coating film formed in (1) was measured using a hardness meter (HM500; manufactured by Fischer). The results obtained at this time are shown in Table 3 below. At this time, the surface hardness was evaluated based on the following criteria.

< Evaluation Criteria >

○: surface hardness 250 N/mm ² or more

△: surface hardness of 150 N/mm ² or more to less than 200 N/mm ²

×: surface hardness less than 150 N/mm ²

(5) Adhesion: Minimum formation pattern size

In the exposure step, a mask with a pattern thickness of 1 to 20 μm was used in 1 μm increments, and the minimum pattern was evaluated based on the mask size in which the pattern remained. The evaluation results are shown in Table 3 below.

(6) Reliability: film thickness change after NMP immersion

After the coating film was formed in (1), the thickness change by the NMP solvent was confirmed by the following Equation 2. Specifically, when the finally completed coating film was immersed in NMP for 1 hour, the thickness before and after immersion was measured to calculate the change rate (NMP reliability) by Equation 2 below. The evaluation results are shown in Table 3 below.

[Equation 2]

NMP reliability = {(film thickness after NMP immersion) / (film thickness before NMP immersion)} × 100 (%)

(7) Developability evaluation

A 5 cm X 5 cm glass substrate (Corning) was washed with a neutral detergent and water, and then dried. Each of the black photosensitive resin compositions prepared in Examples and Comparative Examples was spin-coated on the glass substrate to have a final film thickness of 1.5 μm, and then dried at 100° C. for 5 minutes to remove the solvent. Then, the developability was evaluated by immersion in an aqueous alkali solution for 2 minutes, and is shown in Table 3 below. At this time, developability was evaluated based on the following criteria.

< Evaluation Criteria >

○: dissolved

△: dissolution after peeling

×: peeling

Outgas (ppm) remaining film rate surface hardness adhesion reliability developability Example 1 5,105,351 87% ○ 8μm 97% ○ Example 2 4,350,844 93% ○ 5μm 98% ○ Example 3 4,789,518 90% ○ 3μm 97% ○ Example 4 4,458,183 92% ○ 3μm 98% ○ Example 5 3,841,894 94% ○ 3μm 98% ○ Example 6 3,784,914 93% ○ 3μm 98% ○ Example 7 4,241,871 90% ○ 4μm 97% ○ Example 8 5,378,947 89% ○ 5μm 95% ○ Example 9 6,987,184 85% ○ 8μm 90% ○ Comparative Example 1 8,516,791 80% △ 15μm 83% ○ Comparative Example 2 7,342,873 82% ○ 10μm 88% ○ Comparative Example 3 9,127,654 79% △ 16μm 82% ○ Comparative Example 4 5,428,702 90% ○ 15μm 90% X Comparative Example 5 7,215,788 85% ○ 15μm 87% X Comparative Example 6 9,751,754 83% ○ 20μm 79% △

From the results of Table 3, in the case of Examples 1 to 8 using the photopolymerizable compound and the alkali-soluble resin according to the present invention, the amount of outgas generated was significantly less than that of Comparative Examples, and the residual film rate was 85% or more, and the surface hardness 250 N/mm ² or more and a minimum pattern of 8 μm or less is formed, so it has excellent adhesion and excellent physical properties, as well as 90% or more reliability in NMP and excellent developability in aqueous alkali solution, resulting in chemical resistance It can also be seen that the excellent However, in the case of Example 8, which further included trifunctional or less acrylate monomer, or Example 9, in which the content of 15 or more functional dendrimer acrylate oligomer was too small, it was better than Comparative Examples, but overall physical properties were somewhat decline could be observed.

On the other hand, as in Comparative Examples 1 to 7, when the photopolymerizable compound or alkali-soluble resin does not satisfy the conditions according to the present invention, outgas is significantly generated, and it can be seen that the effect in physical properties and reliability is lowered. .

Claims (10)

It contains a colorant, a photopolymerizable compound, an alkali-soluble resin, a photoinitiator and a solvent,
The photopolymerizable compound includes an acrylate oligomer of tetrafunctional or more and 8 functional or less and a dendrimer acrylate oligomer having 15 or more functionalities and less than 25 functional functionalities,
The alkali-soluble resin is a cardo-based resin having a weight average molecular weight of 5,000 to 10,000, a black photosensitive resin composition. The method according to claim 1,
With respect to the total weight of the photopolymerizable compound, 30 to 90% by weight of the acrylate oligomer of tetrafunctional or more and 8 functional or less and 10 to 50% by weight of the 15 functional or more and less than 25 functional dendrimer acrylate oligomer, A black photosensitive resin composition. The method according to claim 1,
The photopolymerizable compound will further include an acrylate oligomer of 8 functional or more and less than 15 functional, black photosensitive resin composition. The method according to claim 1,
The cardo-based resin has an acid value of 50 to 120 mgKOH/g, a black photosensitive resin composition. The method according to claim 1,
The colorant is a black photosensitive resin composition comprising at least one selected from the group consisting of a black pigment or dye, and an organic pigment or dye. The method according to claim 1,
Based on the total weight of the black photosensitive resin composition,
1 to 50% by weight of the colorant;
10 to 70% by weight of the photopolymerizable compound,
1 to 50% by weight of the alkali-soluble resin,
0.1 to 10% by weight of the photopolymerization initiator, and
The black photosensitive resin composition comprising 30 to 80% by weight of the solvent. The method according to claim 1,
The black photosensitive resin composition further comprising an additive. A pixel defining film manufactured using the black photosensitive resin composition of any one of claims 1 to 7. An organic light emitting device comprising the pixel defining layer of claim 8 . A display device comprising the organic light emitting device of claim 9 .