KR102696681B1 - Photosensitive Resin Composition, Protrusion Pattern and Display Device Using the Same - Google Patents

Abstract

The present invention relates to a photosensitive resin composition, a protruding pattern using the same, and an image display device. The photosensitive resin composition according to the present invention can form a pattern exhibiting a high refractive index without using inorganic particles, and has excellent pattern characteristics and chemical resistance even when cured at low temperatures.

Description

Photosensitive resin composition, protrusion pattern and display device using the same {Photosensitive Resin Composition, Protrusion Pattern and Display Device Using the Same}

The present invention relates to a photosensitive resin composition, a protruding pattern, and an image display device using the same, and more specifically, to a photosensitive resin composition capable of forming a pattern exhibiting a high refractive index without using inorganic particles and having excellent pattern characteristics and chemical resistance even when cured at low temperatures, and a protruding pattern and an image display device using the same.

Organic light emitting diodes (OLEDs) are expected to be the next-generation display and lighting devices due to their advantages such as fast response speed, wide viewing angle, and low-voltage operation.

In general, OLEDs have an organic layer made of light-emitting materials or charge-transfer materials positioned between the upper and lower electrodes. OLEDs have a structure in which materials with different refractive indices are laminated, so reflection occurs at the interfaces of these materials, and thus the efficiency of light extraction to the outside is low.

Specifically, the refractive index of the organic light-emitting layer constituting the OLED is approximately 1.7, the refractive index of the ITO used as the transparent electrode is 2.0, and the refractive index of the glass substrate is 1.5. In this case, the ratio of guided light that is trapped in the transparent electrode or organic layer and cannot be extracted is approximately 45%, and the ratio of substrate guided light that is trapped in the substrate and cannot be extracted is approximately 35%. Therefore, only about 20% of the light emitted from the OLED is extracted to the outside.

Various studies are being conducted to solve this problem, and a representative example is the micro lens array. The micro lens array increases the light extraction efficiency by changing the angle of incidence at the interface between the glass substrate of the OLED element and the air surface.

The microlens array must exhibit a high refractive index higher than that of the glass substrate. Normally, inorganic particles have a high refractive index compared to organic substances, but when a pattern is formed using a photosensitive resin composition containing inorganic particles, the surface roughness of the pattern increases, cracks occur, and the bending resistance is low, making it difficult to apply to a flexible display device.

Therefore, there is a need for development of a photosensitive resin composition capable of forming a pattern exhibiting a high refractive index higher than the refractive index of a glass substrate without using inorganic particles.

In addition, there is a demand for the development of a photosensitive resin composition that exhibits excellent pattern characteristics even when low-temperature curing is performed for application to flexible display devices and has excellent chemical resistance so that the film thickness does not change even during post-processing.

Republic of Korea Publication Patent No. 10-2021-0052452

One object of the present invention is to provide a photosensitive resin composition capable of forming a pattern exhibiting a high refractive index without using inorganic particles, and having excellent pattern characteristics and chemical resistance even when cured at low temperatures.

Another object of the present invention is to provide a protruding pattern formed using the photosensitive resin composition.

Another object of the present invention is to provide an image display device including the above-mentioned protruding pattern.

On the one hand, the present invention provides a photosensitive resin composition comprising an alkali-soluble resin comprising at least one repeating unit of the following chemical formulas 1 to 6, a cardo-type photopolymerizable compound, a multifunctional acrylate photopolymerizable compound, a photopolymerization initiator, and a solvent.

[Chemical Formula 1]

[Chemical formula 2]

[Chemical Formula 3]

[Chemical Formula 4]

[Chemical Formula 5]

[Chemical formula 6]

In the above formula,

X and X' are each independently a single bond, -CO-, -SO ₂ -, -C(CF ₃ ) ₂ -, -Si(CH ₃ ) ₂ -, -CH ₂ -, -C(CH ₃ ) ₂ -, -O-, , , , , , , , , , , , or And,

Y is an acid anhydride residue,

Z is an acid dianhydride residue,

R' is a hydrogen atom, an ethyl group, a phenyl group, -C ₂ H ₄ Cl, -C ₂ H ₄ OH or -CH ₂ CH=CH ₂ ,

R1, R1', R2, R2', R3, R3', R4, R4', R5, R5', R6 and R6' are each independently a hydrogen atom or a methyl group,

R7, R7', R8 and R8' are each independently a C ₁ -C ₆ alkylene group, wherein the alkylene group is or is not interrupted by at least one of an ester bond, a C ₆ -C ₁₄ cycloalkylene group and an arylene group,

R9, R9', R10, R10', R11, R11', R12 and R12' are each independently a hydrogen atom, a halogen atom or a C ₁ -C ₆ alkyl group,

m and n are each independently an integer from 1 to 30,

t and u are each independently integers from 0 to 1,

P is each independently , , , or And,

R13 and R14 are each independently a hydrogen atom, a hydroxyl group, a thiol group, an amino group, a nitro group or a halogen atom,

Ar1 is each independently an aryl group,

Y' is an acid anhydride residue,

Z' is an acid dianhydride residue,

A is O, S, NR', Si(R') ₂ or Se,

a and b are each independently an integer from 1 to 6,

p and q are each independently an integer from 1 to 30.

According to one embodiment of the present invention, a photosensitive resin composition can exhibit a refractive index of 1.60 or more at a wavelength of 550 nm in a cured film.

In one embodiment of the present invention, the acid anhydride may be selected from the group consisting of maleic anhydride, succinic anhydride, itaconic anhydride, phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, methylendomethylenetetrahydrophthalic anhydride, chlorendic anhydride, and methyltetrahydrophthalic anhydride.

In one embodiment of the present invention, the acid dianhydride may be selected from the group consisting of pyromellitic anhydride, benzophenone tetracarboxylic acid dianhydride, biphenyl tetracarboxylic acid dianhydride, and biphenyl ether tetracarboxylic acid dianhydride.

In one embodiment of the present invention, the cardo-based photopolymerizable compound may include a compound represented by any one of the following chemical formulas 7 to 9.

[Chemical formula 7]

[Chemical formula 8]

[Chemical formula 9]

In the above formula,

R15 and R16 are each independently a hydrogen atom, a hydroxyl group, a thiol group, an amino group, a nitro group, a halogen atom, or a polymerizable functional group having 2 to 20 carbon atoms and an unsaturated double bond, and at least one of R15 or R16 is a polymerizable functional group having 2 to 20 carbon atoms and an unsaturated double bond.

In one embodiment of the present invention, R15 and R16 are each independently a hydrogen atom, a hydroxyl group, a thiol group, an amino group, a nitro group, a halogen atom, or and at least one of R15 or R16 And,

R17 is a C ₁ -C ₆ alkylene group, wherein the alkylene group is or is not interrupted by at least one of an ester bond, a C ₆ -C ₁₄ cycloalkylene group, and an arylene group,

R18 can be a hydrogen atom or a methyl group.

In one embodiment of the present invention, the cardo-based photopolymerizable compound may be included in an amount of 30 to 70 parts by weight per 100 parts by weight of the alkali-soluble resin.

In one embodiment of the present invention, the multifunctional acrylate photopolymerizable compound may be included in an amount of 30 to 120 parts by weight per 100 parts by weight of the alkali-soluble resin.

The photosensitive resin composition according to one embodiment of the present invention may additionally contain a multifunctional thiol compound.

The photosensitive resin composition according to one embodiment of the present invention may not contain inorganic particles.

On the other hand, the present invention provides a protruding pattern formed using the photosensitive resin composition.

On the other hand, the present invention provides an image display device including the above-mentioned protruding pattern.

The photosensitive resin composition according to the present invention can form a pattern exhibiting a high refractive index of 1.60 or more at a wavelength of 550 nm without using inorganic particles by using a cardo-based alkali-soluble resin containing a repeating unit of a specific structure, a cardo-based photopolymerizable compound, and a multifunctional acrylate photopolymerizable compound, and has excellent pattern characteristics such as development speed, residue, adhesion, and surface hardness even when cured at low temperatures, and has excellent chemical resistance to a developer and monomer.

Hereinafter, the present invention will be described in more detail.

One embodiment of the present invention relates to a photosensitive resin composition comprising an alkali-soluble resin (A), a cardo-type photopolymerizable compound (B), a multifunctional acrylate photopolymerizable compound (C), a photopolymerization initiator (D), and a solvent (E).

According to one embodiment of the present invention, a photosensitive resin composition comprises a cardo-based alkali-soluble resin having a repeating unit having a specific structure, a cardo-based photopolymerizable compound, and a multifunctional acrylate photopolymerizable compound, thereby forming a pattern having a high refractive index of 1.60 or higher, for example, 1.60 to 1.7, at a wavelength of 550 nm without using inorganic particles. Accordingly, an insulating film patterned through a photolithography process using the photosensitive resin composition according to one embodiment of the present invention can be used as a light extraction material for a self-luminous device, and thereby significantly improves the light extraction efficiency and luminance of light emitted from the self-luminous device.

In addition, the photosensitive resin composition according to one embodiment of the present invention exhibits a ratio of development speeds so that the exposed and unexposed areas are clear even when cured at low temperatures, has excellent pattern characteristics such as residue, adhesion, and surface hardness, and has excellent chemical resistance to a developer and/or monomer used in a post-process due to its excellent curing degree.

Alkali soluble resin (A)

In one embodiment of the present invention, the alkali-soluble resin (A) is a component that usually has reactivity due to the action of light or heat and provides solubility for an alkaline developer used in a developing process when forming a pattern.

The above alkali-soluble resin (A) includes a cardo-based alkali-soluble resin. The cardo-based alkali-soluble resin includes at least one repeating unit of the following chemical formulas 1 to 6.

[Chemical Formula 1]

[Chemical formula 2]

[Chemical Formula 3]

[Chemical Formula 4]

[Chemical Formula 5]

[Chemical formula 6]

In the above formula,

X and X' are each independently a single bond, -CO-, -SO ₂ -, -C(CF ₃ ) ₂ -, -Si(CH ₃ ) ₂ -, -CH ₂ -, -C(CH ₃ ) ₂ -, -O-, , , , , , , , , , , , or And,

Y is an acid anhydride residue,

Z is an acid dianhydride residue,

R' is a hydrogen atom, an ethyl group, a phenyl group, -C ₂ H ₄ Cl, -C ₂ H ₄ OH or -CH ₂ CH=CH ₂ ,

R1, R1', R2, R2', R3, R3', R4, R4', R5, R5', R6 and R6' are each independently a hydrogen atom or a methyl group,

R7, R7', R8 and R8' are each independently a C ₁ -C ₆ alkylene group, wherein the alkylene group is or is not interrupted by at least one of an ester bond, a C ₆ -C ₁₄ cycloalkylene group and an arylene group,

R9, R9', R10, R10', R11, R11', R12 and R12' are each independently a hydrogen atom, a halogen atom or a C ₁ -C ₆ alkyl group,

m and n are each independently an integer from 1 to 30,

t and u are each independently integers from 0 to 1,

P is each independently , , , or And,

R13 and R14 are each independently a hydrogen atom, a hydroxyl group, a thiol group, an amino group, a nitro group or a halogen atom,

Ar1 is each independently an aryl group,

Y' is an acid anhydride residue,

Z' is an acid dianhydride residue,

A is O, S, NR', Si(R') ₂ or Se,

a and b are each independently an integer from 1 to 6,

p and q are each independently an integer from 1 to 30.

As used herein, the C ₁ -C ₆ alkylene group means a straight-chain or branched divalent hydrocarbon having 1 to 6 carbon atoms, and examples thereof include, but are not limited to, methylene, ethylene, propylene, butylene, etc.

As used herein, the C ₆ -C ₁₄ cycloalkylene group means a simple or fused ring divalent hydrocarbon having 6 to 14 carbon atoms, and examples thereof include, but are not limited to, cyclohexylene, cycloheptylene, and cyclooctylene.

The arylene group used herein includes both divalent aromatic groups, heteroaromatic groups, and partially reduced derivatives thereof. The aromatic group is a simple or fused ring having 5 to 15 members, and the heteroaromatic group means an aromatic group containing at least one oxygen, sulfur, or nitrogen. Representative examples of arylene groups include, but are not limited to, phenylene, naphthylene, pyridinylene, furanylene, thiophenylene, indolylene, quinolinylene, imidazolinylene, oxazolylene, thiazolylene, and tetrahydronaphthylene.

As used herein, the C ₁ -C ₆ alkyl group means a straight-chain or branched monovalent hydrocarbon having 1 to 6 carbon atoms, and examples thereof include, but are not limited to, methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, t-butyl, n-pentyl, n-hexyl, and the like.

The aryl group used in the present specification includes a monovalent aromatic group, a heteroaromatic group, and partially reduced derivatives thereof. The aromatic group is a simple or fused ring having 5 to 15 members, and the heteroaromatic group means an aromatic group containing at least one oxygen, sulfur, or nitrogen. Representative examples of aryl groups include, but are not limited to, phenyl, naphthyl, pyridinyl, furanyl, thiophenyl, indolyl, quinolinyl, imidazolinyl, oxazolyl, thiazolyl, and tetrahydronaphthyl.

The acid anhydride residue used in this specification can be obtained by reacting the synthetic intermediate of the cardo resin of the present invention with an acid anhydride. The acid anhydride capable of introducing the acid anhydride residue is not particularly limited, and examples thereof include maleic anhydride, succinic anhydride, itaconic anhydride, phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, methylendomethylene tetrahydrophthalic anhydride, chlorenedic anhydride, and methyl tetrahydrophthalic anhydride. These acid anhydrides can be used alone or in combination of two or more.

The acid dianhydride residue used in this specification can be obtained by reacting the synthetic intermediate of the cardo resin of the present invention with an acid dianhydride. The acid dianhydride into which the acid dianhydride residue can be introduced is not particularly limited, and examples thereof include pyromellitic anhydride, benzophenone tetracarboxylic dianhydride, biphenyl tetracarboxylic dianhydride, biphenyl ether tetracarboxylic dianhydride, and the like. These acid dianhydrides can be used alone or in combination of two or more.

In this specification, the acid dianhydride refers to a compound containing two acid anhydride groups in the molecule.

The photosensitive resin composition according to the present invention can form a pattern exhibiting a high refractive index of 1.60 or more at a wavelength of 550 nm by including a cardo-based alkali-soluble resin including at least one repeating unit among the chemical formulas 1 to 6, has excellent pattern characteristics even when cured at low temperatures, and has excellent chemical resistance to a developer and/or monomer used in a post-process.

The method for producing the above-mentioned cardo-based alkali-soluble resin is not particularly limited. For example, the cardo-based alkali-soluble resin can be produced by reacting a bisphenol compound and an epoxy compound to synthesize a bisphenol epoxy compound, reacting the synthesized bisphenol epoxy compound with an acrylate compound to synthesize a bisphenol epoxy acrylate compound, and then reacting the bisphenol epoxy acrylate compound with an acid anhydride, an acid dianhydride, or a mixture thereof.

The above-described cardo-based alkali-soluble resin may have an acid value of 20 to 200 (KOH mg/g). When the acid value is in the above range, the solubility in the developer is improved, so that the non-exposed portion is easily dissolved and the sensitivity is increased, and as a result, the pattern of the exposed portion remains during development, thereby improving the film remaining ratio, which is preferable. Here, the acid value is a value measured as the amount (mg) of potassium hydroxide required to neutralize 1 g of the polymer, and can be typically obtained by titration using a potassium hydroxide aqueous solution.

The polystyrene-converted weight average molecular weight (hereinafter simply referred to as “weight average molecular weight”) measured by gel permeation chromatography (GPC; using tetrahydrofuran as a dissolution solvent) of the above-mentioned cardo-based alkali-soluble resin is preferably 1,000 g/mol to 30,000 g/mol. When the weight average molecular weight is within the above range, the sensitivity of the non-exposed portion to dissolve in a developer increases, and excellent chemical resistance can be exhibited in a post-process performed after thermal curing, which is preferable.

The molecular weight distribution [weight average molecular weight (Mw)/number average molecular weight (Mn)] of the above-mentioned cardo-based alkali-soluble resin is preferably 1.0 to 6.0, more preferably 1.5 to 6.0. A molecular weight distribution of 1.5 to 6.0 is preferable because it has excellent reliability.

The alkali-soluble resin (A) may be included in an amount of 10 to 70 wt%, preferably 20 to 50 wt%, based on 100 wt% of the total solid content of the photosensitive resin composition. When the content of the alkali-soluble resin is less than 10 wt%, the sensitivity of the non-exposed portion to be dissolved in the developer may be reduced, resulting in the generation of residues. When the content exceeds 70 wt%, the degree of photocuring may be reduced, resulting in the exposure portion being dissolved in the developer.

In the present invention, the solid content of the photosensitive resin composition means the total amount of components from which the solvent has been removed.

Cardo-type photopolymerizable compound (B)

In one embodiment of the present invention, the cardo-based photopolymerizable compound (B) is a cardo-based compound that can be polymerized by the action of light and a photopolymerization initiator described below, and serves to increase the refractive index.

The above-mentioned cardo-type photopolymerizable compound may include a compound represented by any one of the following chemical formulas 7 to 9.

[Chemical formula 7]

[Chemical formula 8]

[Chemical formula 9]

In the above formula,

R15 and R16 are each independently a hydrogen atom, a hydroxyl group, a thiol group, an amino group, a nitro group, a halogen atom, or a polymerizable functional group having 2 to 20 carbon atoms and an unsaturated double bond, and at least one of R15 or R16 is a polymerizable functional group having 2 to 20 carbon atoms and an unsaturated double bond.

In one embodiment of the present invention, R15 and R16 are each independently a hydrogen atom, a hydroxyl group, a thiol group, an amino group, a nitro group, a halogen atom, or and at least one of R15 or R16 And,

R17 is a C ₁ -C ₆ alkylene group, wherein the alkylene group is or is not interrupted by at least one of an ester bond, a C ₆ -C ₁₄ cycloalkylene group, and an arylene group,

R18 can be a hydrogen atom or a methyl group.

Specifically, the above-mentioned cardo-type photopolymerizable compound may include a compound represented by any one of the following chemical formulas 10 to 14.

[Chemical Formula 10]

[Chemical Formula 11]

[Chemical Formula 12]

[Chemical Formula 13]

[Chemical Formula 14]

In one embodiment of the present invention, the cardo-type photopolymerizable compound may be included in an amount of 30 to 70 parts by weight, preferably 30 to 60 parts by weight, relative to 100 parts by weight of the alkali-soluble resin. If the cardo-type photopolymerizable compound is included in an amount less than 30 parts by weight relative to 100 parts by weight of the alkali-soluble resin, the refractive index may not be improved, and if it is included in an amount exceeding 70 parts by weight, the sensitivity of the non-exposed portion to be dissolved in a developer may be reduced, resulting in the generation of a residue.

The above-mentioned cardo-type photopolymerizable compound (B) may be included in an amount of 5 to 50 wt%, preferably 10 to 30 wt%, based on 100 wt% of the total solid content of the photosensitive resin composition. When the content of the above-mentioned cardo-type photopolymerizable compound is less than 5 wt%, the refractive index may not be improved, and when it exceeds 50 wt%, the sensitivity of the non-exposed portion to be dissolved in the developer may be reduced, resulting in the generation of residue.

Multifunctional acrylate photopolymerizable compound (C)

In one embodiment of the present invention, the multifunctional acrylate photopolymerizable compound (C) is a compound that can be polymerized by the action of light and a photopolymerization initiator to be described later, and is polymerized by an exposure process to improve mechanical properties such as hardness and adhesion of a pattern, or to play a role in supplementing the developability of the alkali-soluble resin.

The above multifunctional acrylate photopolymerizable compound is a compound having two or more, preferably three or more, and more preferably four or more (meth)acryloyloxy groups in the molecule.

Examples of the above-mentioned multifunctional acrylate photopolymerizable compounds include bifunctional acrylate photopolymerizable compounds such as 1,6-hexanediol di(meth)acrylate, ethylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, bis(acryloyloxyethyl)ether of bisphenol A or 3-methylpentanediol di(meth)acrylate; trifunctional acrylate photopolymerizable compounds such as trimethylolpropane tri(meth)acrylate, ethoxylated trimethylolpropane tri(meth)acrylate, propoxylated trimethylolpropane tri(meth)acrylate, and pentaerythritol tri(meth)acrylate. Examples of the photopolymerizable compounds include tetrafunctional acrylate photopolymerizable compounds such as ditrimethylolpropane tetra(meth)acrylate, pentaerythritol tetra(meth)acrylate, and ethoxylated pentaerythritol tetra(meth)acrylate; pentafunctional acrylate photopolymerizable compounds such as dipentaerythritol penta(meth)acrylate; and hexafunctional acrylate photopolymerizable compounds such as ethoxylated dipentaerythritol hexa(meth)acrylate, propoxylated dipentaerythritol hexa(meth)acrylate, and dipentaerythritol hexa(meth)acrylate.

The multifunctional acrylate photopolymerizable compounds exemplified above can be used alone or in combination of two or more.

In one embodiment of the present invention, the multifunctional acrylate photopolymerizable compound may be included in an amount of 30 to 120 parts by weight, preferably 40 to 110 parts by weight, based on 100 parts by weight of the alkali-soluble resin. If the multifunctional acrylate photopolymerizable compound is included in an amount less than 30 parts by weight based on 100 parts by weight of the alkali-soluble resin, the degree of photocuring may be reduced and the exposed portion may be dissolved in the developer, and if it is included in an amount exceeding 120 parts by weight, a residue may be generated on the underlying substrate or the refractive index may be reduced.

The above multifunctional acrylate photopolymerizable compound (C) may be included in an amount of 5 to 80 wt%, preferably 10 to 60 wt%, based on 100 wt% of the total solid content of the photosensitive resin composition. When the content of the above multifunctional acrylate photopolymerizable compound is less than 5 wt%, the degree of photocuring may be reduced and the exposed portion may be dissolved in the developer, and when it exceeds 80 wt%, a residue may be generated on the underlying substrate or the refractive index may be reduced.

Photopolymerization initiator (D)

In one embodiment of the present invention, the photopolymerization initiator (D) can be used without particular limitation as long as it can polymerize the cardo-based photopolymerizable compound (B) and the multifunctional acrylate photopolymerizable compound (C). In particular, the photopolymerization initiator (D) is preferably at least one compound selected from the group consisting of acetophenone-based compounds, benzophenone-based compounds, triazine-based compounds, biimidazole-based compounds, oxime-based compounds, and thioxanthone-based compounds, from the viewpoints of polymerization characteristics, initiation efficiency, absorption wavelength, availability, price, etc., and an acetophenone-based compound is particularly preferable.

Specific examples of the above acetophenone compounds include diethoxyacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, benzyldimethylketal, 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-2-dimethylamino-1-(4-morpholinophenyl)butan-1-one, 2-hydroxy-2-methyl-1-[4-(1-methylvinyl)phenyl]propan-1-one, 2-(4-methylbenzyl)-2-(dimethylamino)-1-(4-morpholinophenyl)butan-1-one, etc.

Examples of the above benzophenone compounds include benzophenone, 0-benzoylbenzoate methyl, 4-phenylbenzophenone, 4-benzoyl-4'-methyldiphenyl sulfide, 3,3',4,4'-tetra(tert-butylperoxycarbonyl)benzophenone, 2,4,6-trimethylbenzophenone, etc.

Specific examples of the above triazine compounds include 2,4-bis(trichloromethyl)-6-(4-methoxyphenyl)-1,3,5-triazine, 2,4-bis(trichloromethyl)-6-(4-methoxynaphthyl)-1,3,5-triazine, 2,4-bis(trichloromethyl)-6-piperonyl-1,3,5-triazine, 2,4-bis(trichloromethyl)-6-(4-methoxystyryl)-1,3,5-triazine, 2,4-bis(trichloromethyl)-6-[2-(5-methylfuran-2-yl)ethenyl]-1,3,5-triazine, 2,4-bis(trichloromethyl)-6-[2-(furan-2-yl)ethenyl]-1,3,5-triazine, Examples thereof include 2,4-bis(trichloromethyl)-6-[2-(4-diethylamino-2-methylphenyl)ethenyl]-1,3,5-triazine, 2,4-bis(trichloromethyl)-6-[2-(3,4-dimethoxyphenyl)ethenyl]-1,3,5-triazine, etc.

Specific examples of the above biimidazole compounds 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, 2,2-bis(2,6-dichlorophenyl)-4,4',5,5'-tetraphenyl-1,2'-biimidazole, or biimidazole compounds in which the phenyl group at the 4,4',5,5' position is substituted by a carboalkoxy group. Among these, 2,2'-bis(2-chlorophenyl)-4,4',5,5'-tetraphenylbiimidazole, 2,2'-bis(2,3-dichlorophenyl)-4,4',5,5'-tetraphenylbiimidazole, and 2,2-bis(2,6-dichlorophenyl)-4,4',5,5'-tetraphenyl-1,2'-biimidazole are preferably used.

Specific examples of the above oxime compounds include o-ethoxycarbonyl-α-oxyimino-1-phenylpropan-1-one, 1,2-octadione, -1-(4-phenylthio)phenyl, -2-(o-benzoyloxime), ethanone, -1-(9-ethyl)-6-(2-methylbenzoyl-3-yl)-, 1-(o-acetyloxime), etc. Commercially available products include CGI-124 (Ciba-Geigy), CGI-224 (Ciba-Geigy), Irgacure OXE-01 (BASF), Irgacure OXE-02 (BASF), N-1919 (Adeka), NCI-831 (Adeka), etc.

Examples of the above thioxanthone compounds include 2-isopropylthioxanthone, 2,4-diethylthioxanthone, 2,4-dichlorothioxanthone, 1-chloro-4-propoxythioxanthone, etc.

In addition, within a range that does not impair the effects of the present invention, a photopolymerization initiator other than the above may be additionally used in combination. Examples thereof include benzoin compounds or anthracene compounds, and these may be used singly or in combination of two or more.

Examples of the above benzoin compounds include benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, and benzoin isobutyl ether.

Examples of the above anthracene compounds include 9,10-dimethoxyanthracene, 2-ethyl-9,10-dimethoxyanthracene, 9,10-diethoxyanthracene, or 2-ethyl-9,10-diethoxyanthracene.

In addition, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, 10-butyl-2-chloroacridone, 2-ethylanthraquinone, 9,10-phenanthrenequinone, camphorquinone, methyl phenylchlorooxylate, or titanocene compounds can be additionally used in combination as photopolymerization initiators.

The above photopolymerization initiator (D) may be included in an amount of 1 to 15 wt%, preferably 3 to 10 wt%, based on 100 wt% of the total solid content of the photosensitive resin composition. The above content range takes into consideration the photopolymerization speed and the properties of the final coating film. If it is less than the above range, the polymerization speed may be low, which may lengthen the overall process time. On the other hand, if it exceeds the above range, the crosslinking reaction may be excessive due to excessive reaction, which may deteriorate the properties of the coating film. Therefore, it is appropriately used within the above range.

In addition, a photopolymerization initiation assistant may be used together with the photopolymerization initiator. When the photopolymerization initiation assistant is used together with the photopolymerization initiator, the photosensitive resin composition becomes more sensitive, thereby improving productivity, and thus is preferable. As the photopolymerization initiation assistant, at least one compound selected from the group consisting of amine and carboxylic acid compounds may be preferably used.

It is preferable to use such photopolymerization initiation assistant in an amount of typically 10 moles or less, preferably 0.01 to 5 moles per mole of photopolymerization initiator. When the photopolymerization initiation assistant is used within the above range, the polymerization efficiency can be increased, and the productivity can be improved.

Solvent (E)

In one embodiment of the present invention, the solvent contained in the photosensitive resin composition is not particularly limited, and various organic solvents used in the field of photosensitive resin compositions can be used.

Specific examples thereof 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; methyl ethyl ketone, acetone, methyl amyl ketone, and methyl isobutyl ketone; Examples include ketones such as 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, in terms of applicability and drying property, it is preferable to use an organic solvent having a boiling point of 100°C to 200°C, more preferably an alkylene glycol alkyl ether acetate, a ketone, an ester such as ethyl 3-ethoxypropionate or methyl 3-methoxypropionate, and even more preferably a propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, cyclohexanone, ethyl 3-ethoxypropionate, methyl 3-methoxypropionate, etc. can be used. These solvents can be used alone or in mixtures of two or more.

The above solvent (E) may be included in an amount of usually 60 to 90 wt%, preferably 70 to 85 wt%, based on 100 wt% of the total photosensitive resin composition. When the above range is satisfied, the coating property tends to be improved when applied using a coating device such as a roll coater, a spin coater, a slit and spin coater, a slit coater (sometimes also called a die coater), or an inkjet, which is preferable.

Multifunctional thiol compound (F)

The photosensitive resin composition according to one embodiment of the present invention may additionally contain a multifunctional thiol compound (F).

The above multifunctional thiol compound (F) is a component that improves the degree of curing and increases the refractive index of the pattern, and is a compound having two or more, preferably three or more, thiol groups in the molecule.

For example, the above Polyfunctional thiol compounds include butane-1,4-diyl bis(mercaptoacetate), ethoxylated pentaerythritol tetra(3-mercaptopropionate), trimethylolpropane tri(3-mercaptopropionate), trimethylolpropane tri(3-mercaptoacetate), glycol di-(3-mercaptopropionate), ethoxylated trimethylolpropane tri(3-mercaptopropionate), glycol dimercapto acetate, ethoxylated glycol dimercaptoacetate, 1,4-bis(3-mercaptobutyryloxy)butane, tris[2-(3-mercaptopropionyloxy)ethyl]isocyanurate, 1,3,5-tris(3-mercaptobutyloxyethyl)-1,3,5-triazine-2,4,6(1H, 3H, 5H)-trione, It can be pentaerythritol tetrakis(3-mercaptopropionate), pentaerythritol tetrakis(3-mercaptobutyrate), pentaerythritol tetrakis(2-mercaptoacetate), dipentaerythritol hexakis(3-mercaptopropionate), 1,6-hexanedithiol, 1,3-propanedithiol, 1,2-ethanedithiol, polyethyleneglycol dithiol comprising 1 to 10 ethylene glycol repeating units, or a combination thereof.

The above multifunctional thiol compound (F) may be included in an amount of 20 wt% or less, for example, 0.5 to 20 wt%, preferably 1 to 10 wt%, based on 100 wt% of the total solid content of the photosensitive resin composition. When the content of the multifunctional thiol compound exceeds 20 wt%, the non-exposed portion may not be developed in a developer.

Additive (G)

The photosensitive resin composition according to one embodiment of the present invention may additionally contain additives such as a surfactant, an adhesion promoter, and an antioxidant, in addition to the above-described components, as necessary.

As the above surfactants, for example, polyoxyethylene alkyl ethers, polyoxyethylene alkyl phenyl ethers, polyethylene glycol diesters, sorbitan fatty acid esters, fatty acid-modified polyesters, tertiary amine-modified polyurethanes, polyethylene imines, etc., and in addition, there are trade names such as KP (manufactured by Shin-Etsu Chemical Co., Ltd.), POLYFLOW (manufactured by Kyoeisha Chemical Co., Ltd.), EFTOP (manufactured by Tochem Products Co., Ltd.), MEGAFAC (manufactured by Dainippon Ink & Chemical Co., Ltd.), Flourad (manufactured by Sumitomo 3M Co., Ltd.), Asahi guard, Surflon (all manufactured by Asahi Glass Co., Ltd.), SOLSPERSE (manufactured by Zeneca Co., Ltd.), EFKA (manufactured by EFKA Chemicals Co., Ltd.), PB 821 (manufactured by Ajinomoto Co., Ltd.), and DISPER. Examples include BYK (manufactured by BYK).

Examples of the adhesion promoter include vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris(2-methoxyethoxy)silane, N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, N-(2-aminoethyl)-8-aminooctyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-chloropropylmethyldimethoxysilane, 3-chloropropyltrimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, and the like.

Specific examples of antioxidants include 2,2'-thiobis(4-methyl-6-t-butylphenol), 2,6-di-t-butyl-4-methylphenol, etc.

The above additive may be included in an amount of 10 wt% or less, for example, 0.1 to 10 wt%, preferably 0.1 to 5 wt%, based on 100 wt% of the total solid content of the photosensitive resin composition, but is not limited thereto.

The photosensitive resin composition according to one embodiment of the present invention may not contain inorganic particles. That is, the photosensitive resin composition according to one embodiment of the present invention may not contain inorganic particles such as scattering particles such as metal oxide particles, fillers such as glass, silica, alumina, etc.

Accordingly, the photosensitive resin composition according to one embodiment of the present invention can have a reduced surface roughness of a pattern, prevent crack occurrence, and have sufficient bending resistance for application to a flexible display device.

One embodiment of the present invention relates to a protruding pattern formed using the photosensitive resin composition described above.

The above protruding pattern can be utilized in a microlens array used to increase the light extraction efficiency of a self-luminous device.

The above protruding pattern may have a shape such as a hemisphere, trapezoid, or cone.

The above-described protruding pattern can be formed by applying the above-described photosensitive resin composition on a substrate, exposing and developing it in a predetermined pattern, and then performing a post-baking.

First, the photosensitive resin composition of the present invention is applied to a substrate and then heated and dried to remove volatile components such as solvents, thereby obtaining a smooth coating film.

Application methods include, for example, inkjet printing, spin coating, flexible coating, roll coating, slit and spin coating, or slit coating.

After application, heat drying (pre-bake) or drying under reduced pressure is performed, and then heating is performed to volatilize volatile components such as solvents. The heating temperature at this time is relatively low, at 70 to 100°C.

The film thus obtained is irradiated with ultraviolet rays through a mask for forming the desired pattern. At this time, it is preferable to use a device such as a mask aligner or a stepper so that parallel rays are irradiated evenly over the entire exposure area and accurate alignment of the mask and substrate is achieved. When irradiated with ultraviolet rays, the area irradiated with ultraviolet rays is cured.

The above ultraviolet rays may be used including g-line (wavelength: 436 nm), h-line, i-line (wavelength: 365 nm), etc. The amount of ultraviolet ray may be appropriately selected as needed.

Afterwards, a process of developing is performed by bringing the cured film into contact with a developer to dissolve the unexposed area.

The above developing method may be any of the liquid addition method, dipping method, spraying method, etc. In addition, the substrate may be tilted at any angle during developing.

After development, wash and post-bake at a relatively low temperature of 70 to 100°C for 10 to 60 minutes.

One embodiment of the present invention relates to an image display device including the above-described protruding pattern. The image display device may include, but is not limited to, a liquid crystal display (LCD), an organic light emitting diode (OLED), and the like, and may include any image display device known in the relevant technical field to which the image display device is applicable. In particular, the image display device may be a flexible display.

Hereinafter, the present invention will be described in more detail by examples, comparative examples, and experimental examples. These examples, comparative examples, and experimental examples are only for explaining the present invention, and it is obvious to those skilled in the art that the scope of the present invention is not limited thereto.

Synthesis Example 1: Cardo-based alkali-soluble resin (A-1)

In a reactor, 138 g of 9,9'-bis(4-glycidyloxyphenyl)fluorene, a bisphenol epoxy compound (Hear Chem), 54 g of 2-carboxyethyl acrylate, 1.4 g of benzyltriethylammonium chloride (Daejung Chemicals), 1 g of triphenylphosphine (Aldrich), 128 g of propylene glycol methyl ethyl acetate (Daicel Chemical), and 0.5 g of hydroquinone were placed, the temperature was increased to 120°C, and maintained for 12 hours to synthesize a compound represented by the following chemical formula 11.

60 g of the compound represented by the chemical formula 11, 11 g of biphenyltetracarboxylic acid di-anhydride (Mitsubishi Gas Co.), 3 g of tetrahydrophthalic anhydride (Aldrich Co.), 20 g of propylene glycol methyl ethyl acetate (Daicel Chemical Co.), and 0.1 g of N,N'-tetramethylammonium chloride were placed in a reactor, the temperature was increased to 120°C, and maintained for 2 hours to synthesize a resin represented by the chemical formula 15 below. The weight average molecular weight of the obtained resin was 5,400 g/mol.

[Chemical Formula 11]

[Chemical Formula 15]

Synthesis Example 2: Cardo-based alkali-soluble resin (A-2)

In a reactor, 138 g of 9,9'-bis(4-glycidyloxyphenyl)fluorene, a bisphenol epoxy compound (Hear Chem), 54 g of mono-2-acryloyloxyethyl succinate, 1.4 g of benzyltriethylammonium chloride (Daejung Chemicals), 1 g of triphenylphosphine (Aldrich), 128 g of propylglycolmethylethylacetate (Daicel Chemical), and 0.5 g of hydroquinone were placed, the temperature was increased to 120°C, and maintained for 12 hours to synthesize a compound represented by the following chemical formula 12.

In a reactor, 60 g of the compound represented by the chemical formula 12, 11 g of biphenyltetracarboxylic acid di-anhydride (Mitsubishi Gas Co.), 3 g of tetrahydrophthalic anhydride (Aldrich Co.), 20 g of propyl glycol methyl ethyl acetate (Daicel Chemical Co.), and 0.1 g of N,N'-tetramethylammonium chlorite were placed, the temperature was raised to 120°C, and maintained for 2 hours to synthesize a resin represented by the chemical formula 16 below. The weight average molecular weight of the obtained resin was 5,400 g/mol.

[Chemical Formula 12]

[Chemical Formula 16]

Synthesis Example 3: Cardo-based alkali-soluble resin (A-3)

In a 3000 ml three-necked round bottom flask, 3',6'-dihydroxyspiro(fluorene-9,9-xanthene) (364.4 g) and t-butylammonium bromide (0.4159 g) were mixed, 2359 g of epichlorohydrin was added, and the mixture was heated to 90°C for reaction. When 3',6'-dihydroxyspiro(fluorene-9,9-xanthene) was completely consumed as analyzed by liquid chromatography, the mixture was cooled to 30°C, and 50% NaOH aqueous solution (3 equivalents) was slowly added. When epichlorohydrin was completely consumed as analyzed by liquid chromatography, the mixture was extracted with dichloromethane, washed three times, and the organic layer was dried over magnesium sulfate. Dichloromethane was distilled under reduced pressure, and dichloromethane and Recrystallization was performed using a mixed solvent of methanol (50:50, v/v).

After mixing 1 equivalent of the synthesized epoxy compound, 0.004 equivalent of t-butylammonium bromide, 0.001 equivalent of 2,6-diisobutylphenol, and 2.2 equivalents of acrylic acid, 24.89 g of the solvent propylene glycol monomethyl ether acetate was added and mixed. The reaction solution was heated to 90 to 100°C and dissolved while blowing air at 25 ml/min. While the reaction solution was cloudy, the temperature was heated to 120°C and completely dissolved. When the solution became transparent and the viscosity increased, the acid value was measured and stirred until the acid value was less than 1.0 mgKOH/g. It took 11 hours for the acid value to reach the target (0.8). After the reaction was completed, the temperature of the reactor was lowered to room temperature to obtain a colorless and transparent compound of the following chemical formula 13.

[Chemical Formula 13]

To 307.0 g of the compound of the above chemical formula 13, 600 g of propylene glycol monomethyl ether acetate was added and dissolved, and then 78 g of biphenyl tetracarboxylic dianhydride and 1 g of tetraethylammonium bromide were mixed and the temperature was gradually increased to react at 110-115°C 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 6 hours to obtain a resin. The disappearance of the anhydride was confirmed by IR spectrum.

Synthesis Example 4: Cardo-based alkali-soluble resin (A-4)

In a 3000-mL three-necked round bottom flask, 364.4 g of 4,4′-(9H-xanthene-9,9-diyl)diphenol and 0.4159 g of t-butylammonium bromide were mixed, 2359 g of epichlorohydrin was added, and the mixture was heated to 90°C to react. After analysis by liquid chromatography of 4,4′-(9H-xanthene-9,9-diyl)diphenol, the mixture was cooled to 30°C and 50% NaOH aqueous solution (3 equivalents) was slowly added. When the epichlorohydrin was completely consumed as analyzed by liquid chromatography, the mixture was extracted with dichloromethane, washed three times, dried the organic layer over magnesium sulfate, distilled off dichloromethane under reduced pressure, and recrystallized using a mixed solvent of dichloromethane and methanol (50:50, v/v).

After mixing 1 equivalent of the synthesized epoxy compound, 0.004 equivalent of t-butylammonium bromide, 0.001 equivalent of 2,6-diisobutylphenol, and 2.2 equivalents of acrylic acid, 24.89 g of the solvent propylene glycol monomethyl ether acetate was added and mixed. The reaction solution was heated to 90 to 100°C and dissolved while blowing air at 25 ml/min. While the reaction solution was cloudy, the temperature was heated to 120°C and completely dissolved. When the solution became transparent and the viscosity increased, the acid value was measured and stirred until the acid value was less than 1.0 mgKOH/g. It took 11 hours for the acid value to reach the target (0.8). After the reaction was completed, the temperature of the reactor was lowered to room temperature to obtain a colorless and transparent compound of the following chemical formula 14.

[Chemical Formula 14]

To 307.0 g of the compound of the above chemical formula 14, 600 g of propylene glycol monomethyl ether acetate was added and dissolved, and then 78 g of biphenyl tetracarboxylic dianhydride and 1 g of tetraethylammonium bromide were mixed and the temperature was gradually increased to react at 110-115°C 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 6 hours to obtain a resin. The disappearance of the anhydride was confirmed by IR spectrum.

Synthesis Example 5: Cardo-based alkali-soluble resin (A-5)

Step 1

[Reaction Formula 1]

After installing a reflux condenser and a thermometer in a three-necked flask, 42.5 g of 9,9-bisphenolfluorene was added and 220 mL of 2-(chloromethyl)oxirane was measured and injected. After adding 100 mg of tetrabutylammonium bromide, stirring was started and the temperature was increased to 90°C. After confirming that the unreacted material content was less than 0.3%, distillation was performed under reduced pressure.

After lowering the temperature to 30℃, dichloromethane was injected and NaOH was slowly added. After confirming that the product was 96% or higher by high-performance liquid chromatography (HPLC), 5% HCl was added dropwise to terminate the reaction. The reactant was extracted and separated into layers, and the organic layer was washed with water and washed until neutral. The organic layer was dried over MgSO ₄ and concentrated by vacuum distillation using a rotary evaporator. Dichloromethane was added to the concentrated product, and methanol was added while raising the temperature to 40℃ and stirring, then the solution temperature was lowered and stirred. The generated solid was filtered and dried in vacuum at room temperature to obtain 52.7 g (yield 94%) of a white solid powder. Its structure was confirmed by ¹ H NMR.

^1H NMR in CDCl ₃ : 7.75 (2H), 7.35-7.254(6H), 7.08 (4H), 6.74 (4H), 4.13 (2H), 3.89 (2H), 3.30 (2H), 2.87 (2H), 2.71 (2H).

Step 2

[Reaction Formula 2]

After installing a reflux condenser and a thermometer in a three-necked flask, the reactant of step 1 (1000 g), 524 g of thiophenol, and 617 g of ethanol were added and stirred. 328 g of triethylamine was slowly added dropwise to the reaction solution. After confirming that the starting material had disappeared by high-performance liquid chromatography (HPLC), the reaction was terminated. After completion of the reaction, ethanol was removed by distillation under reduced pressure. The organic matter was dissolved in dichloromethane, washed with water, and then dichloromethane was removed by distillation under reduced pressure. The concentrated organic matter was dissolved in ethyl acetate, and ether solvent was added dropwise and stirred for 30 minutes. The compound was distilled under reduced pressure to obtain 945 g (yield 64%) of pale yellow oil. Its structure was confirmed by ¹ H NMR.

^1H NMR in CDCl ₃ : 7.82 (2H), 7.38-6.72 (20H), 6.51 (4H), 4.00 (2H), 3.97 (2H), 3.89 (2H), 3.20 (2H), 3.01 (2H), 2.64 (2H).

Step 3

After installing a reflux condenser and a thermometer in a three-necked flask, 200 g of 3,3'-(((9H-fluorene-9,9-diyl)bis(4,1-phenylene))bis(oxy))bis(1-phenylthio)propan-2-ol) monomer synthesized in the above step 2 dissolved in 50% PGMEA solvent was added and the temperature was increased to 115°C. At 115°C, 31.1 g of 3,3',4,4'-biphenyltetracarboxylic dianhydride was added dropwise, and the mixture was stirred while maintaining 115°C for 6 hours. After adding 7.35 g of phthalic anhydride and stirring for 2 more hours, the reaction was terminated. After cooling, a resin having a weight-average molecular weight of 3,500 g/mol was obtained.

Synthesis Example 6: Cardo-based alkali-soluble resin (A-6)

After installing a reflux condenser and a thermometer in a three-necked flask, 200 g of 3,3'-(((9H-fluorene-9,9-diyl)bis(4,1-phenylene))bis(oxy))bis(1-(phenylthio)propan-2-ol)) monomer synthesized in step 2 of Synthesis Example 5 dissolved in 50% PGMEA solvent was added and the temperature was increased to 115°C. At 115°C, 21.1 g of pyromellitic dianhydride was added dropwise, and the mixture was stirred while maintaining 115°C for 6 hours. After adding 7.35 g of phthalic anhydride and stirring for 2 more hours, the reaction was terminated. After cooling, a resin having a weight-average molecular weight of 4,500 g/mol was obtained.

Synthesis Example 7: Acrylic alkali-soluble resin (A-7)

In a three-necked flask equipped with a reflux condenser, a thermometer, a dropping lot, and a nitrogen inlet tube, 100 parts by weight of propylene glycol monomethyl ether acetate, 100 parts by weight of propylene glycol monomethyl ether, 5 parts by weight of AIBN, 23.0 parts by weight of vinyl toluene, 1.6 parts by weight of 4-methylstyrene, 46.0 parts by weight of glycidyl methacrylate, and 3 parts by weight of n-dodecyl mercapto were charged and replaced with nitrogen. Thereafter, the temperature of the reaction solution was increased to 80°C with stirring and the reaction was performed for 4 hours. Subsequently, the temperature of the reaction solution was lowered to room temperature, and the flask atmosphere was replaced from nitrogen to air, after which 0.2 parts by weight of triethylamine, 0.1 parts by weight of 4-methoxy phenol, and 23.3 parts by weight of acrylic acid were charged and the reaction was performed at 100°C for 6 hours. Afterwards, the temperature of the reaction solution was lowered to room temperature, 6.0 parts by weight of succinic anhydride was added, and the reaction was performed at 80°C for 6 hours.

The weight average molecular weight of the alkali-soluble resin synthesized in this way was 3,350 g/mol.

Synthesis Example 8: Acrylic alkali-soluble resin (A-8)

In a three-necked flask equipped with a reflux condenser, a thermometer, a dropping lot, and a nitrogen inlet tube, 120 parts by weight of propylene glycol monomethyl ether acetate, 80 parts by weight of propylene glycol monomethyl ether, 2 parts by weight of AIBN, 13.0 parts by weight of acrylic acid, 10 parts by weight of benzyl methacrylate, 57.0 parts by weight of 4-methylstyrene, 20 parts by weight of methyl methacrylate, and 3 parts by weight of n-dodecyl mercapto were charged and replaced with nitrogen. Thereafter, the temperature of the reaction solution was raised to 80°C with stirring and the reaction was performed for 8 hours.

The weight average molecular weight of the alkali-soluble resin thus synthesized was 14,950 g/mol.

Synthesis Example 9: Acrylic alkali-soluble resin (A-9)

A three-necked flask equipped with a reflux condenser, a thermometer, a dropping lot, and a nitrogen inlet tube was made into a nitrogen atmosphere by flowing nitrogen at a rate of 0.02 L/min, 150 g of diethylene glycol methyl ethyl ether was added, and heated to 70°C with stirring. Then, 132.2 g (0.60 mol) of a compound represented by the following chemical formula 17, 55.3 g (0.30 mol) of 3-ethyl-3-oxetanyl methacrylate, and 8.6 g (0.10 mol) of methacrylic acid were dissolved in 150 g of diethylene glycol methyl ethyl ether to prepare a solution. The prepared solution was dropped into a flask using a dropping funnel, and then a solution of 27.9 g (0.11 mol) of the polymerization initiator 2,2'-azobis(2,4-dimethylvaleronitrile) dissolved in 200 g of diethylene glycol methyl ethyl ether was dropped into the flask using a separate dropping funnel over 4 hours. After the dropping of the polymerization initiator solution was completed, the flask was maintained at 70°C for 4 hours and then cooled to room temperature. The weight average molecular weight of the alkali-soluble resin thus synthesized was 4,700 g/mol.

[Chemical Formula 17]

Synthesis Example 10: Acrylic alkali-soluble resin (A-10)

After the addition of the polymerization initiator solution was completed, the same procedure as in Synthesis Example 9 was followed, except that the temperature was maintained at 70°C for 8 hours.

The alkali-soluble resin synthesized in this way had a weight-average molecular weight of 12,300 g/mol.

Examples and Comparative Examples: Preparation of Photosensitive Resin Composition

A photosensitive resin composition was prepared by mixing each component according to the compositions in Table 1 and Table 2 below (weight %).

Example Alkali soluble resin Cardo-type photopolymerizable compound Multifunctional acrylate photopolymerizable compound Multifunctional thiol compounds Photopolymerization initiator solvent Additives total A B C F D E G 1 A-1 B-1 0.89 0 0.23 7.5 0.04 10 0.89 0.45 2 A-2 B-1 0.89 0 0.23 7.5 0.04 10 0.89 0.45 3 A-3 B-1 0.89 0 0.23 7.5 0.04 10 0.89 0.45 4 A-4 B-1 0.89 0 0.23 7.5 0.04 10 0.89 0.45 5 A-5 B-1 0.89 0 0.23 7.5 0.04 10 0.89 0.45 6 A-6 B-1 0.89 0 0.23 7.5 0.04 10 0.89 0.45 7 A-1 B-2 0.89 0 0.23 7.5 0.04 10 0.89 0.45 8 A-1 B-3 0.89 0 0.23 7.5 0.04 10 0.89 0.45 9 A-1 B-4 0.89 0 0.23 7.5 0.04 10 0.89 0.45 10 A-1 B-5 0.89 0 0.23 7.5 0.04 10 0.89 0.45 11 A-1 B-1 0.87 0.07 0.22 7.5 0.04 10 0.87 0.43 12 A-1 B-1 0.85 0.12 0.22 7.5 0.04 10 0.85 0.42 13 A-5 B-1 0.89 0 0.23 7.5 0.04 10 1.03 0.31 14 A-5 B-1 0.89 0 0.23 7.5 0.04 10 0.79 0.55 15 A-5 B-1 0.4 0 0.23 7.5 0.04 10 1.2 0.63 16 A-5 B-1 0.98 0 0.23 7.5 0.04 10 0.82 0.43

Comparative example Alkali soluble resin Cardo-type photopolymerizable compound Multifunctional acrylate photopolymerizable compound Multifunctional thiol compounds Photopolymerization initiator solvent Additives total A B C F D E G 1 A-7 B-1 0.89 0 0.23 7.5 0.04 10 0.89 0.45 2 A-8 B-1 0.89 0 0.23 7.5 0.04 10 0.89 0.45 3 A-9 B-1 0.89 0 0.23 7.5 0.04 10 0.89 0.45 4 A-10 B-1 0.89 0 0.23 7.5 0.04 10 0.89 0.45 5 A-7 B-5 0.89 0 0.23 7.5 0.04 10 0.89 0.45 6 A-6 - 1.12 0 0.22 7.5 0.04 10 1.12 0 7 A-6 - 1.09 0.06 0.22 7.5 0.04 10 1.09 0 8 A-7 B-1 0 0.07 0.22 7.5 0.04 10 1.3 0.87 9 A-7 - 0 0.07 0.22 7.5 0.04 10 2.17 0 10 A-7 - 0 0 0.23 7.5 0.04 10 2.23 0 11 A-6 B-1 0 0 0.23 7.5 0.04 10 1.32 0.91

A-1: Cardo-based alkali-soluble resin of Synthesis Example 1

A-2: Cardo-based alkali-soluble resin of synthesis example 2

A-3: Cardo-based alkali-soluble resin of synthetic example 3

A-4: Cardo-based alkali-soluble resin of synthetic example 4

A-5: Cardo-based alkali-soluble resin of Synthesis Example 5

A-6: Cardo-based alkali-soluble resin of synthetic example 6

A-7: Acrylic alkali-soluble resin of synthetic example 7

A-8: Acrylic alkali-soluble resin of synthetic example 8

A-9: Acrylic alkali-soluble resin of synthetic example 9

A-10: Acrylic alkali-soluble resin of synthetic example 10

B-1: Compound represented by chemical formula 10

B-2: Compound represented by chemical formula 11

B-3: Compound represented by chemical formula 12

B-4: Compound represented by chemical formula 13

B-5: Compound represented by chemical formula 14

C: Dipentaerythritol hexaacrylate (manufactured by Japan Gunpowder)

D: 2-Benzyl-2-dimethylamino-1-(4-morpholinophenyl)butan-1-one (Irgacure 369), manufactured by Ciba Specialty Chemical

E: Propylene glycol monomethyl ether acetate

F: Dipentaerythritol hexakis(3-mercaptopropionate) (manufactured by SC Organic Chemical)

G: N-2-(Aminoethyl)-8-aminooctyltrimethoxysilane (KBM-6803, Shin-Etsu)

Experimental Example 1: Evaluation of Pattern Properties

Using the photosensitive resin compositions manufactured in the above examples and comparative examples, patterns were manufactured as follows.

For the above pattern, the refractive index, development speed, residue, adhesion, surface hardness, and chemical resistance to TMAH and DPHA were evaluated as follows, and the results are shown in Table 3 below.

<How to make a pattern>

A 5×5 cm glass substrate (Eagle 2000; manufactured by Corning Inc.) was sequentially washed with a neutral detergent, water, and alcohol, and then dried. The photosensitive resin compositions manufactured in the examples and comparative examples were each spin-coated on the glass substrate, and then pre-baked at 80° C. for 120 seconds using a hot plate. After the pre-baked substrate was cooled to room temperature, light was irradiated at an exposure dose of 30 mJ/cm2 (based on 365 nm) using an exposure device (MA6; manufactured by Karl Suss Co., Ltd.) at a distance of 50 μm from a quartz glass photomask.

At this time, a photomask having circular openings (dot patterns) with diameters of 5, 10, 20, and 30 ㎛ and having patterns with a mutual interval of 30 ㎛ formed on the same plane was used. After light irradiation, development was performed in a 2.38% tetramethylammonium hydroxide (TMAH) aqueous solution for 60 seconds, washed with ultrapure water, and dried under nitrogen to form a pattern on the photosensitive resin composition film. Post-baking was performed at 85° C. for 2 hours in an oven.

(1) Refractive index measurement

Except for not using a mask, a cured film formed by exposure was measured at incident angles of 65, 70, and 75° under the conditions of 25°C and 50%RH using an ellipsometer (J. A. Woollam Co., M-2000) in a wavelength range of 200 nm to 1000 nm for linear polarization. The measured linear polarization measurement data (Ellipsometry data(Ψ, Δ)) were optimized (fitted) to the Cauchy model of the following mathematical expression 1 using Complete EASE software so that MSE was 70 or less, and the refractive index at a wavelength of 550 nm was calculated.

[Mathematical Formula 1]

In the above mathematical expression 1, n(λ) is the refractive index at wavelength λ, λ is in the range of 200 nm to 1000 nm, and A, B, and C are Cauchy parameters.

(2) Development speed of the exposed area

The substrate, which had undergone pre-baking in the same manner as the method for manufacturing the above pattern, was immersed in a 2.38% tetramethylammonium hydroxide aqueous solution, and the time until the photosensitive resin composition was completely dissolved was measured to evaluate the development speed according to the following evaluation criteria.

<Evaluation criteria>

Phenomena Speed: Time is rounded to the nearest 10 seconds

No phenomenon within 120 seconds: Marked as ×

(3) Residue

The presence of residue around the dot pattern obtained in the above pattern manufacturing method was observed using an optical microscope and evaluated according to the following evaluation criteria.

<Evaluation criteria>

No residue: ○

Residue: ×

(4) Adhesion

The minimum mask size in which the dot pattern obtained as in the above pattern manufacturing method adheres more than 90% to the lower substrate was measured and evaluated according to the evaluation criteria below.

<Evaluation criteria>

Adhesion of 90% or more of 5 ㎛ dot pattern: 5

Adhesion of 90% or more of 10 ㎛ dot pattern: 10

Adhesion of 90% or more of 20 ㎛ dot pattern: 20

Adhesion of 90% or more of 30 ㎛ dot pattern: 30

No phenomenon or pattern loss: ×

(5) Surface hardness

The degree of hardening of the cured film formed by exposure in the same manner as the manufacturing method of the above pattern, except that a mask was not used, was measured using a hardness tester (HM500, Fischer). At this time, the surface hardness was evaluated according to the following evaluation criteria.

<Evaluation criteria>

◎: Surface hardness 40 or higher

○: Surface hardness 30 or more but less than 40

△: Surface hardness 10 or more and less than 30

×: Surface hardness less than 10

(6) 2.38% TMAH chemical resistance

The cured film formed in the same manner as in the manufacturing method of the above pattern, except that no mask was used, was immersed in a 2.38% tetraammonium hydroxide aqueous solution for 2 minutes, and the change in film thickness (unit: ㎛) was measured.

(7) DPHA chemical resistance

Dipentaerythritol hexaacrylate (DPHA) was added dropwise to the cured film formed in the same manner as in the manufacturing method of the above pattern except that a mask was not used, and after leaving it for 2 minutes, it was washed with ultrapure water and dried under nitrogen, and the change in film thickness (unit: ㎛) was measured.

　 Refractive index phenomenon speed Residue Adhesion Surface hardness 2.38% TMAH chemical resistance DPHA chemical resistance Example 1 1.62 30 ○ 5 ○ -0.03 0.02 2 1.62 30 ○ 5 ○ -0.02 0.02 3 1.62 40 ○ 5 ○ -0.01 0.02 4 1.62 50 ○ 5 ○ -0.02 0.03 5 1.64 20 ○ 5 ◎ -0.01 0.01 6 1.64 20 ○ 5 ◎ -0.01 0.01 7 1.62 30 ○ 5 ○ -0.03 0.02 8 1.62 30 ○ 5 ○ -0.04 0.03 9 1.62 30 ○ 5 ○ -0.03 0.02 10 1.62 30 ○ 5 ○ -0.04 0.02 11 1.64 40 ○ 5 ○ 0 0.01 12 1.64 50 ○ 5 ○ 0 0 13 1.64 10 ○ 5 ◎ -0.01 0.02 14 1.64 30 ○ 5 ◎ 0 0.01 15 1.65 30 ○ 5 ◎ -0.01 0.02 16 1.64 10 ○ 5 ◎ -0.02 0 Comparative example 1 1.53 20 ○ 5 △ -0.17 0.31 2 1.54 × × 5 △ -0.1 0.2 3 1.53 30 ○ 5 △ -0.13 0.29 4 1.53 × × 5 △ -0.11 0.22 5 1.53 20 ○ 5 △ -0.07 0.17 6 1.51 20 ○ 10 △ -0.09 0.23 7 1.54 30 ○ 5 △ -0.23 0.17 8 1.56 × × 5 △ -0.35 0.46 9 1.54 × × × × × × 10 1.51 × × × × × × 11 1.56 × × 30 × × ×

As shown in Table 3 above, the photosensitive resin compositions of Examples 1 to 16, which include a cardo-based alkali-soluble resin having a repeating unit of a specific structure, a cardo-based photopolymerizable compound, and a multifunctional acrylate photopolymerizable compound, exhibit a high refractive index of 1.60 or more at a wavelength of 550 nm of a pattern formed therefrom without using inorganic particles, and it can be confirmed that the pattern properties such as development speed, residue, adhesion, and surface hardness characteristics are excellent even when cured at a low temperature of 100°C or lower, and the chemical resistance to a developer and monomer is excellent.

On the other hand, the photosensitive resin compositions of Comparative Examples 1 to 8 and 11, which do not contain any one of a cardo-based alkali-soluble resin having a repeating unit of a specific structure, a cardo-based photopolymerizable compound, and a polyfunctional acrylate photopolymerizable compound, exhibited a refractive index of less than 1.60 at a wavelength of 550 nm, and showed poor physical properties such as development speed, residue, adhesion, and surface hardness. In addition, it was confirmed that the photosensitive resin compositions of Comparative Examples 1 to 8 and 11 had poor chemical resistance to a developer used in the developing process and poor chemical resistance to a monomer used in a post-process to form another pattern, resulting in severe film loss and film swelling.

In addition, the photosensitive resin compositions of Comparative Examples 9 and 10, which do not contain either a cardo-type photopolymerizable compound or a multifunctional acrylate photopolymerizable compound, were found to be unable to confirm their characteristics because the exposed portion was dissolved in a 2.38% tetramethylammonium hydroxide (TMAH) aqueous solution and no coating film was formed.

As described above, specific parts of the present invention have been described in detail. It is obvious to those skilled in the art that these specific descriptions are merely preferred implementation examples and that the scope of the present invention is not limited thereto. Those skilled in the art will be able to make various applications and modifications within the scope of the present invention based on the above contents.

Accordingly, the substantial scope of the present invention will be defined by the appended claims and their equivalents.

Claims (12)

A photosensitive resin composition comprising an alkali-soluble resin comprising at least one repeating unit of the following chemical formulas 1 to 6, a cardo-type photopolymerizable compound, a multifunctional acrylate photopolymerizable compound, a photopolymerization initiator, and a solvent,
The above-mentioned cardo-based photopolymerizable compound is included in an amount of 30 to 70 parts by weight per 100 parts by weight of the alkali-soluble resin.
A photosensitive resin composition having a cured film formed using the photosensitive resin composition and exhibiting a refractive index of 1.60 or more at a wavelength of 550 nm:
[Chemical Formula 1]

[Chemical formula 2]

[Chemical Formula 3]

[Chemical Formula 4]

[Chemical Formula 5]

[Chemical formula 6]

In the above formula,
X and X' are each independently a single bond, -CO-, -SO ₂ -, -C(CF ₃ ) ₂ -, -Si(CH ₃ ) ₂ -, -CH ₂ -, -C(CH ₃ ) ₂ -, -O-, , , , , , , , , , , , or And,
Y is an acid anhydride residue,
Z is an acid dianhydride residue,
R' is a hydrogen atom, an ethyl group, a phenyl group, -C ₂ H ₄ Cl, -C ₂ H ₄ OH or -CH ₂ CH=CH ₂ ,
R1, R1', R2, R2', R3, R3', R4, R4', R5, R5', R6 and R6' are each independently a hydrogen atom or a methyl group,
R7, R7', R8 and R8' are each independently a C ₁ -C ₆ alkylene group, wherein the alkylene group is or is not interrupted by at least one of an ester bond, a C ₆ -C ₁₄ cycloalkylene group and an arylene group,
R9, R9', R10, R10', R11, R11', R12 and R12' are each independently a hydrogen atom, a halogen atom or a C ₁ -C ₆ alkyl group,
m and n are each independently an integer from 1 to 30,
t and u are each independently integers from 0 to 1,
P is each independently , , , or And,
R13 and R14 are each independently a hydrogen atom, a hydroxyl group, a thiol group, an amino group, a nitro group or a halogen atom,
Ar1 is each independently an aryl group,
Y' is an acid anhydride residue,
Z' is an acid dianhydride residue,
A is O, S, NR', Si(R') ₂ or Se,
a and b are each independently an integer from 1 to 6,
p and q are each independently an integer from 1 to 30. delete A photosensitive resin composition in claim 1, wherein the acid anhydride is selected from the group consisting of maleic anhydride, succinic anhydride, itaconic anhydride, phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, methylendomethylene tetrahydrophthalic anhydride, chlorendic anhydride, and methyltetrahydrophthalic anhydride. A photosensitive resin composition in claim 1, wherein the acid dianhydride is selected from the group consisting of pyromellitic anhydride, benzophenone tetracarboxylic acid dianhydride, biphenyl tetracarboxylic acid dianhydride, and biphenyl ether tetracarboxylic acid dianhydride. In the first paragraph, the photopolymerizable compound of the cardo system is a photosensitive resin composition comprising a compound represented by any one of the following chemical formulas 7 to 9:
[Chemical formula 7]

[Chemical formula 8]

[Chemical formula 9]

In the above formula,
R15 and R16 are each independently a hydrogen atom, a hydroxyl group, a thiol group, an amino group, a nitro group, a halogen atom, or a polymerizable functional group having 2 to 20 carbon atoms and an unsaturated double bond, and at least one of R15 or R16 is a polymerizable functional group having 2 to 20 carbon atoms and an unsaturated double bond. In the fifth paragraph, R15 and R16 are each independently a hydrogen atom, a hydroxyl group, a thiol group, an amino group, a nitro group, a halogen atom, or and at least one of R15 or R16 And,
R17 is a C ₁ -C ₆ alkylene group, wherein the alkylene group is or is not interrupted by at least one of an ester bond, a C ₆ -C ₁₄ cycloalkylene group, and an arylene group,
A photosensitive resin composition wherein R18 is a hydrogen atom or a methyl group. delete A photosensitive resin composition in claim 1, wherein the multifunctional acrylate photopolymerizable compound is contained in an amount of 30 to 120 parts by weight per 100 parts by weight of the alkali-soluble resin. A photosensitive resin composition further comprising a multifunctional thiol compound in claim 1. A photosensitive resin composition according to claim 1, which does not contain inorganic particles. A protruding pattern formed using a photosensitive resin composition according to any one of claims 1, 3 to 6, and 8 to 10. An image display device including a protruding pattern according to Article 11.