TWI893156B - Photosensitive resin composition for spacer and overcoat - Google Patents

Abstract

The present invention relates to a photosensitive resin composition and applications thereof. The aforementioned photosensitive resin composition includes an alkali-soluble resin (A), a compound having an ethylenically unsaturated group (B), a photo initiator (C), and an organic solvent (D). The photosensitive resin composition can be used to produce a spacer or an overcoat, and has favorable elastic recovery rate and photosensitivity.

Description

Photosensitive resin composition for spacers and protective films

The present invention relates to a photosensitive resin composition, a spacer or protective film formed using the composition, and a liquid crystal display device thereof; in particular, to a photosensitive resin composition for a spacer or protective film having excellent elastic recovery rate and photosensitivity, a spacer or protective film formed using the composition, and a liquid crystal display device thereof.

Typically, the pixels and black matrix printed on the surface of the color filter layer produce uneven surfaces. Therefore, a protective film can be formed on the surface of the color filter layer to conceal these unevennesses, thereby achieving the required flatness. Furthermore, the manufacturing of optical components such as liquid crystal displays (LCDs) and solid-state imaging devices requires rigorous processing procedures. For example, immersion in acidic or alkaline solvents, or sputtering to form the wiring electrode layer, can easily cause localized corrosion or high temperatures on the substrate surface.

Therefore, to prevent surface damage, a protective film must be applied to the component surface. This film must have excellent adhesion to the substrate and possess high transparency, high surface hardness, and a smooth surface. It must also be highly heat-resistant and light-resistant to prevent discoloration, yellowing, or whitening over extended use. Furthermore, the film must exhibit excellent resistance to water, chemicals, solvents, acids, and alkalis.

On the other hand, in conventional color liquid crystal display devices, to maintain a fixed distance between the two substrates (the liquid crystal interlayer gap), conventional color liquid crystal display devices randomly spray polystyrene beads or silicone beads onto the entire substrate, where the diameter of the polystyrene beads or silicone beads is the distance between the two substrates. However, this conventional method causes uneven distribution of the beads, which causes backlight light to be scattered by the beads, further reducing the contrast of the display device. Therefore, the use of a photosensitive resin composition for spacer formation through photolithography has gradually become the mainstream in the industry.

The spacer is formed by coating a substrate with a photosensitive resin composition. A photomask with a designated pattern is placed between the substrate and an exposure source, and the spacer is exposed and developed. This method allows spacers to be formed at designated locations outside of the R, G, and B pixels, resolving conventional issues. Furthermore, the thickness of the coating formed by the photosensitive resin composition can be used to control the liquid crystal gap, making the distance of the liquid crystal gap easily controllable and offering the advantage of high precision.

Because the protective film or spacer is formed on the color filter or substrate, it requires extremely high transparency. When used in liquid crystal displays (LCDs), a protective film or spacer with poor transparency will result in insufficient brightness, affecting the display quality.

To improve the transparency of a protective film or interstitial structure, Japanese Patent Application Laid-Open No. 2010-054561 discloses a photosensitive resin composition for a protective film. The composition comprises an alkali-soluble binder resin, an ethylenically unsaturated compound, a photoinitiator, and a solvent. The ethylenically unsaturated compound has an unsaturated bond equivalent weight of 90 g/ep to 450 g/eq, and the number of unsaturated double bonds in a single ethylenically unsaturated compound is 2 to 4. Furthermore, the weight-average molecular weight of the alkali-soluble binder resin is 10,000 to 20,000.

Secondly, Japanese Patent Laid-Open No. 2004-240241 discloses a photosensitive resin composition comprising a copolymer, a polymer having an ethylenically unsaturated group, and a photoinitiator. The copolymer is obtained by copolymerizing an ethylenically unsaturated carboxylic acid (anhydride), a compound having an ethylenically unsaturated group containing an epoxy group, and another compound having an ethylenically unsaturated group. The photoinitiator may be 2-butanedione-[4-methylthiophenyl]-2-(O-oxime acetate), 1,2-butanedione-1-(4-morpholinophenyl)-2-(O-benzoyl oxime), 1,2-octanedione-1-[4-phenylthiophenyl]-2-[O-(4-methylbenzoyl)oxime], or the like. However, although this photosensitive resin composition can produce a highly transparent protective film or spacer, it suffers from the disadvantages of poor elastic recovery and photosensitivity.

In view of this, there is an urgent need to develop a photosensitive resin composition that can increase elastic recovery rate and photosensitivity to overcome the various problems of the conventional protective film or spacer.

The present invention provides a photosensitive resin composition, a spacer or protective film formed using the composition, and a liquid crystal display device. In particular, the present invention relates to a photosensitive resin composition for a spacer or protective film having excellent elastic recovery and photosensitivity, a spacer or protective film formed using the composition, and a liquid crystal display device.

The present invention provides a photosensitive resin composition comprising: an alkali-soluble resin (A); a compound having an ethylenically unsaturated group (B); a photoinitiator (C); and an organic solvent (D). The alkali-soluble resin (A) comprises a first alkali-soluble resin (A-1), which is obtained by reacting a copolymer formed from a first mixture with an epoxy-containing compound (a-3), and then with an isocyanate-containing compound (a-4). The first mixture comprises the carboxylic acid-containing ethylenically unsaturated compound (a-1), another copolymerizable ethylenically unsaturated compound (a-2), and a polymerization solvent (s).

In some embodiments, the isocyanate-containing compound (a-4) has a structure shown in the following formula (a4): Formula (a4) In formula (a4), R ₁ is a C ₁ to C ₁₀ alkylene group; and R ₂ is a hydrogen group or a methyl group.

In some embodiments, based on the total usage of the carboxylic acid group-containing ethylenically unsaturated compound (a-1) and the other copolymerizable ethylenically unsaturated compound (a-2) being 1.0 mol, the usage of the carboxylic acid group-containing ethylenically unsaturated compound (a-1) is 0.2 mol to 0.95 mol, and the usage of the other copolymerizable ethylenically unsaturated compound (a-2) is 0.05 mol to 0.8 mol.

In some embodiments, based on the total usage of the carboxylic acid group-containing ethylenically unsaturated compound (a-1) and the other copolymerizable ethylenically unsaturated compound (a-2) being 1.0 mol, the usage of the epoxy group-containing compound (a-3) is 0.18 mol to 0.93 mol, and the usage of the isocyanate group-containing compound (a-4) is 0.02 mol to 0.85 mol.

In some embodiments, the first alkali-soluble resin (A-1) is further reacted with a polycarboxylic acid or its anhydride (a-5).

In some embodiments, based on the total amount of the carboxylic acid group-containing ethylenically unsaturated compound (a-1) and other copolymerizable ethylenically unsaturated compounds (a-2) used being 1.0 mol, the amount of the polycarboxylic acid or its anhydride (a-5) used is 0.1 mol to 0.93 mol.

In some embodiments, the polymerization solvent (s) comprises: an alkyl glycol monoalkyl ether acetate solvent (s-1); and an alkyl glycol monoalkyl ether solvent (s-2).

In some embodiments, based on the total amount of the carboxylic acid group-containing ethylenically unsaturated compound (a-1) and the other copolymerizable ethylenically unsaturated compound (a-2) used being 100 parts by weight, the amount of the alkyl glycol monoalkyl ether acetate solvent used being 60 parts by weight to 600 parts by weight, and the amount of the alkyl glycol monoalkyl ether acetate solvent used being 40 parts by weight to 360 parts by weight.

In some embodiments, based on 100 parts by weight of the alkali-soluble resin (A), the compound having an ethylenically unsaturated group (B) is used in an amount of 30 to 300 parts by weight, the photoinitiator (C) is used in an amount of 10 to 100 parts by weight, and the organic solvent (D) is used in an amount of 120 to 1000 parts by weight.

The present invention further provides a method for forming a spacer or protective film for a liquid crystal display element, characterized in that the method comprises at least the following steps in the following order: (1) applying the aforementioned photosensitive resin composition on a substrate to form a coating film; (2) exposing at least a portion of the coating film; (3) developing the exposed coating film; and (4) heating the developed coating film.

The present invention also provides a liquid crystal display device comprising the aforementioned spacer or protective film.

The present invention provides a photosensitive resin composition comprising: an alkali-soluble resin (A); a compound having an ethylenically unsaturated group (B); a photoinitiator (C); and an organic solvent (D). The alkali-soluble resin (A) comprises a first alkali-soluble resin (A-1), which is obtained by reacting a copolymer formed from a first mixture with an epoxy-containing compound (a-3), and then with an isocyanate-containing compound (a-4). The first mixture comprises the carboxylic acid-containing ethylenically unsaturated compound (a-1), another copolymerizable ethylenically unsaturated compound (a-2), and a polymerization solvent (s).

The carboxylic acid group-containing ethylenically unsaturated compound (a-1) may be a compound comprising a carboxylic acid group or a carboxylic acid anhydride structure, and an unsaturated bond for polymeric bonding. The structure of the carboxylic acid group-containing ethylenically unsaturated compound (a-1) is not particularly limited and may include, but is not limited to, unsaturated monocarboxylic acid compounds, unsaturated dicarboxylic acid compounds, unsaturated anhydride compounds, polycyclic unsaturated carboxylic acid compounds, polycyclic unsaturated dicarboxylic acid compounds, or polycyclic unsaturated anhydride compounds.

Specific examples of the unsaturated monocarboxylic acid compound include, but are not limited to, (meth)acrylic acid, crotonic acid, α-chloroacrylic acid, ethylacrylic acid, cinnamic acid, 2-(meth)acryloyloxyethyl succinate monoester, 2-(meth)acryloyloxyethyl hexahydrophthalate, 2-(meth)acryloylethoxyphthalate, or omega-carboxy polycaprolactone polyol monoacrylate (which can be a product manufactured by Toa Synthetics under the model number ARONIX M-5300).

Specific examples of the unsaturated dicarboxylic acid compound include, but are not limited to, maleic acid, fumaric acid, methylfumaric acid, itaconic acid, or liraconic acid.

The unsaturated acid anhydride compound may be an anhydride compound of the unsaturated dicarboxylic acid compound.

Specific examples of the aforementioned polycyclic unsaturated carboxylic acid compound may include, but are not limited to, 5-carboxybicyclo[2.2.1]hept-2-ene, 5-carboxy-5-methylbicyclo[2.2.1]hept-2-ene, 5-carboxy-5-ethylbicyclo[2.2.1]hept-2-ene, 5-carboxy-6-methylbicyclo[2.2.1]hept-2-ene, or 5-carboxy-6-ethylbicyclo[2.2.1]hept-2-ene.

Specific examples of the aforementioned polycyclic unsaturated dicarboxylic acid compound include, but are not limited to, 5,6-dicarboxybicyclo[2.2.1]hept-2-ene.

The polycyclic unsaturated acid anhydride compound may be an anhydride compound of the polycyclic unsaturated dicarboxylic acid compound.

The carboxylic acid group-containing ethylenically unsaturated compound (a-1) may be used alone or in combination of two or more.

Specific examples of the carboxylic acid group-containing ethylenically unsaturated compound (a-1) include acrylic acid, methacrylic acid, maleic anhydride, 2-methacryloylethoxysuccinate, or 2-methacryloylethoxyhexahydrophthalate.

Based on the total usage amount of the carboxylic acid group-containing ethylenically unsaturated compound (a-1) and other copolymerizable ethylenically unsaturated compounds (a-2) described below being 1.0 mol, the usage amount of the carboxylic acid group-containing ethylenically unsaturated compound (a-1) can be 0.2 mol to 0.95 mol, preferably 0.2 mol to 0.9 mol, and more preferably 0.2 mol to 0.85 mol.

The other copolymerizable ethylenically unsaturated compound (a-2) may be selected from at least one of an acrylate compound having a structure represented by the following formula (a2-1), a compound represented by the following formula (a2-2), and other unsaturated compounds: Formula (a2-1) Formula (a2-2) Formula (a2-3)

In formula (a2-3), X and Y each independently represent a hydrogen atom, a linear alkyl group having 1 to 4 carbon atoms, or a branched alkyl group having 1 to 4 carbon atoms; R ¹ and R ² each independently represent a hydrogen atom, a C ₁ to C ₂₀ alkyl group, which is unsubstituted or substituted; or R ¹ and R ² are bonded to each other to form a ring structure.

Specific examples of the acrylate compound having the structure represented by formula (a2-1) include acrylate compounds having a tricyclodecane skeleton, such as dicyclopentyl (meth)acrylate (trade names FA-513A and FA-513M, manufactured by Hitachi Chemical Co., Ltd.). Specific examples of the acrylate compound having the structure represented by formula (a2-2) include acrylate compounds having a dicyclopentadiene skeleton, such as tricyclo[5.2.1.0 ^2,6 ]dec-8-yl acrylate (trade name FA-511A, manufactured by Hitachi Chemical Co., Ltd.), 2-(tricyclo[5.2.1.0 ^2,6 ]dec-3-en-8(9)-oxy)ethyl (meth)acrylate (dicyclopentenyloxyethyl (meth)acrylate, trade names FA-512A and FA-512M, manufactured by Hitachi Chemical Co., Ltd.). Specific examples of the compound represented by formula (a2-3) include norbornene (bicyclo[2.2.1]hept-2-ene), 5-methylbicyclo[2.2.1]hept-2-ene, 5-ethylbicyclo[2.2.1]hept-2-ene, tetracyclo[4.4.0.1 ^2,5 .1 ^7,10 ]dodec-3-ene, 8-methyltetracyclo[4.4.0.1 ^2,5 .1 ^7,10 ]dodec-3-ene, 8-ethyltetracyclo[4.4.0.1 ^2,5 .1 ^7,10 ]dodec-3-ene, dicyclopentadiene, tricyclo[5.2.1.0 ^2,6 ]dec-8-ene, tricyclo[5.2.1.0 ^2,6 ]dec-3-ene, tricyclo[4.4.0.1 ^{2,5 .1 7,12} .0 ]undec-3-ene, tricyclo[6.2.1.0 ^1,8 ]undec-9-ene, tricyclo[6.2.1.0 ^1,8 ]undec-4-ene, tetracyclo[4.4.0.1 ^2,5 .1 ^7,10 .0 ^1,6 ]dodec-3-ene, 8-methyltetracyclo[4.4.0.1 ^2,5 .1 ^7,10 .0 ^1,6 ]dodec-3-ene, 8-ethylenetetracyclo[4.4.0.1 ^2,5 .1 ^{7,12 .0} ]dodec-3-ene, 8-ethylenetetracyclo[4.4.0.1 ^2,5 .1 ^7,10 .0 ^1,6 ] dodeca-3-ene, pentacyclo[6.5.1.1 ^3,6 .0 ^2,7 .0 ^9,13 ] pentadeca-4-ene, pentacyclo[7.4.0.1 ^2,5 .1 ^9,12 .0 ^8,13 ] pentadeca-3-ene, and the like. The above-mentioned compounds may be used alone or in combination of two or more.

Specific examples of the aforementioned other unsaturated compounds include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, n-butyl (meth)acrylate, n-pentyl (meth)acrylate, n-hexyl (meth)acrylate, n-octyl (meth)acrylate, lauryl (meth)acrylate, n-tetradecyl (meth)acrylate, and n-butyl (meth)acrylate. n-Octadecanyl acrylate, cyclopentyl (meth)acrylate, cyclohexyl (meth)acrylate, methylcyclohexyl (meth)acrylate, ethylcyclohexyl (meth)acrylate, methoxy-triethylene glycol acrylate, ethoxy-diethylene glycol acrylate, methoxy polyethylene glycol methacrylate, methoxy polyethylene glycol acrylate (trade name: AM-90G, manufactured by Shin-Nakamura Chemical Industries, Ltd.), 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, butanetriol mono(meth)acrylate, pentatriol mono(meth)acrylate, 1,4-cyclohexanedimethanol mono(meth)acrylate, ( (Meth)acrylates not having an aromatic ring, such as allyl (meth)acrylate, propynyl (meth)acrylate, 1,1,1-trifluoroethyl (meth)acrylate, perfluoroethyl (meth)acrylate, perfluoro-n-propyl (meth)acrylate, perfluoroisopropyl (meth)acrylate, furyl (meth)acrylate, furylmethyl (meth)acrylate, tetrahydrofuryl (meth)acrylate, pyranyl (meth)acrylate, 3-(N,N-dimethylamino)propyl (meth)acrylate; (Meth)acrylates not having an aromatic ring, such as dicyclopentenyl (meth)acrylate, dicyclohexyl (meth)acrylate, norbornyl (meth)acrylate, (meth)acrylate (Meth)acrylates having a bridged cyclic alkyl group having 10 to 20 carbon atoms, such as 5-methyl norbornyl (meth)acrylate, 5-ethyl norbornyl (meth)acrylate, isobornyl (meth)acrylate, adamantyl (meth)acrylate, and rosin (meth)acrylate; (meth)acrylic acid amides, such as (meth)acrylic acid N,N-dimethylamide, (meth)acrylic acid N,N-diethylamide, (meth)acrylic acid N,N-dipropylamide, (meth)acrylic acid N,N-diisopropylamide, and anthracenyl (meth)acrylate; (meth)acrylic acid anilide, (meth)acrylic acid ) Vinyl compounds such as acrylonitrile, acrolein, vinyl chloride, vinylidene chloride, vinyl fluoride, vinylidene fluoride, N-vinylpyrrolidone, vinylpyridine, and vinyl acetate; diene compounds such as butadiene, 2,3-dimethylbutadiene, isoprene, and chloroprene; unsaturated dicarboxylic acid diester compounds such as diethyl hexanoate, diethyl maleate, diethyl fumarate, and diethyl itaconate; monomaleimide compounds such as N-phenylmaleimide, N-cyclohexylmaleimide, N-laurylmaleimide, and N-(4-hydroxyphenyl)maleimide; and N-(methyl)acryloyl o-phenylenediamine. The above-listed compounds may be used alone or in combination of two or more.

Based on the total usage amount of the carboxylic acid group-containing ethylenically unsaturated compound (a-1) and the other copolymerizable ethylenically unsaturated compound (a-2) being 1.0 mol, the usage amount of the other copolymerizable ethylenically unsaturated compound (a-2) may be 0.05 mol to 0.8 mol, preferably 0.1 mol to 0.8 mol, and more preferably 0.15 mol to 0.8 mol.

Specific examples of the epoxy group-containing compound (a-3) include epoxypropyl (meth)acrylate, 2-epoxypropyloxyethyl (meth)acrylate, 3,4-epoxybutyl (meth)acrylate, 6,7-epoxyheptyl (meth)acrylate, 3,4-epoxycyclohexylmethyl (meth)acrylate and lactone adducts thereof (e.g., Cyclomer A200 and M100 manufactured by DAICEL Chemical Industries, Ltd.), mono(meth)acrylate of 3,4-epoxycyclohexylmethyl-3',4'-epoxycyclohexanecarboxylate, epoxy compounds of dicyclopentenyl (meth)acrylate, and epoxy compounds of dicyclopentenyloxyethyl (meth)acrylate.

Based on a total usage amount of 1.0 mol of the carboxylic acid group-containing ethylenically unsaturated compound (a-1) and the other copolymerizable ethylenically unsaturated compound (a-2), the usage amount of the epoxy group-containing compound (a-3) is 0.18 mol to 0.93 mol, preferably 0.2 mol to 0.9 mol, and more preferably 0.2 mol to 0.85 mol. If the epoxy group-containing compound (a-3) is not used, the photosensitivity of the resulting photosensitive resin composition is poor. Conversely, if the usage amount of the epoxy group-containing compound (a-3) is within the above range, the photosensitivity of the resulting photosensitive resin composition is better.

The isocyanate group-containing compound (a-4) has a structure shown in the following formula (a4): Formula (a4)

In formula (a4), _R1 is a _C1 to _C10 alkylene group. Preferably, _R1 is a _C2 to _C6 alkylene group; and _R2 is hydrogen or methyl.

Specific examples of the isocyanate group-containing compound (a-4) include, but are not limited to, 2-acryloyloxyethyl isocyanate, 2-methacryloylethyl isocyanate, or 2-acryloyloxyethyl isocyanate, with 2-methacryloyloxyethyl isocyanate being preferred.

Based on a total usage amount of 1.0 mol of the carboxylic acid group-containing ethylenically unsaturated compound (a-1) and the other copolymerizable ethylenically unsaturated compound (a-2), the usage amount of the isocyanate group-containing compound (a-4) can be 0.02 mol to 0.85 mol, preferably 0.05 mol to 0.8 mol, and more preferably 0.05 mol to 0.75 mol. If the isocyanate group-containing compound (a-4) is not used, the resulting photosensitive resin composition will have a poor elastic recovery rate. Conversely, if the usage amount of the isocyanate group-containing compound (a-4) is within the above range, the resulting photosensitive resin composition will have a better elastic recovery rate.

The polymerization solvent (s) is not particularly limited and may be, for example, an alkyl glycol monoalkyl ether acetate solvent (s-1), an alkyl glycol monoalkyl ether solvent (s-2), or other solvents.

Examples of the alkyl glycol monoalkyl ether acetate solvent (s-1) include ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, propylene glycol monomethyl ether acetate, and propylene glycol monoethyl ether acetate.

Examples of the alkyl glycol monoalkyl ether solvent (s-2) include ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol mono-n-propyl ether, diethylene glycol mono-n-butyl ether, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol mono-n-propyl ether, dipropylene glycol mono-n-butyl ether, tripropylene glycol monomethyl ether, and tripropylene glycol monoethyl ether.

Examples of the aforementioned other solvents include other ether compounds such as diethylene glycol dimethyl ether, diethylene glycol methyl ethyl ether, diethylene glycol diethyl ether, and tetrahydrofuran; ketone compounds such as methyl ethyl ketone, cyclohexanone, 2-heptanone, and 3-heptanone; methyl 2-hydroxypropionate, ethyl 2-hydroxypropionate, methyl 2-hydroxy-2-methylpropionate, ethyl 2-hydroxy-2-methylpropionate, methyl 3-methoxypropionate, ethyl 3-methoxypropionate, methyl 3-ethoxypropionate, ethyl 3-ethoxypropionate, ethyl ethoxyacetate, ethyl hydroxyacetate, methyl 2-hydroxy-3-methylbutanoate, 3-methyl-3-methoxybutanoate, Ester compounds such as methyl acetate, 3-methyl-3-methoxybutyl propionate, ethyl acetate, n-butyl acetate, n-propyl acetate, isopropyl acetate, n-butyl acetate, isobutyl acetate, n-amyl acetate, isoamyl acetate, n-butyl propionate, ethyl butyrate, n-propyl butyrate, isopropyl butyrate, n-butyl butyrate, methyl pyruvate, ethyl pyruvate, n-propyl pyruvate, methyl acetylacetate, ethyl acetylacetate, and ethyl 2-oxobutyrate; aromatic hydrocarbon compounds such as toluene and xylene; and carboxylic acid amide compounds such as N-methyldipyrrolidone, N,N-dimethylformamide, and N,N-dimethylacetamide. The above solvents may be used alone or in combination of two or more.

The amount of the polymerization solvent (s) used is not particularly limited. The amount is generally 100 to 1,000 parts by weight, preferably 100 to 800 parts by weight, based on 100 parts by weight of the total amount of the carboxylic acid group-containing ethylenically unsaturated compound (a-1) and the other copolymerizable ethylenically unsaturated compound (a-2). In particular, when the amount of the solvent used is 1,000 parts by weight or less, the molecular weight reduction of the copolymer due to chain transfer can be suppressed, and the viscosity of the copolymer can be controlled within an appropriate range. Furthermore, when the amount of the solvent used is 100 parts by weight or more, abnormal polymerization reaction can be prevented, allowing the polymerization reaction to proceed stably, while also preventing coloration or gelation of the copolymer.

Preferably, the polymerization solvent (s) may include both the alkyl glycol monoalkyl ether acetate solvent (s-1) and the alkyl glycol monoalkyl ether solvent (s-2) to further enhance the photosensitivity of the photosensitive resin composition.

Based on a combined usage of 100 parts by weight of the carboxylic acid group-containing ethylenically unsaturated compound (a-1) and the other copolymerizable ethylenically unsaturated compound (a-2), the usage of the alkyl glycol monoalkyl ether acetate solvent (s-1) is 60 to 600 parts by weight, preferably 80 to 750 parts by weight, and more preferably 60 to 700 parts by weight. When the usage of the alkyl glycol monoalkyl ether acetate solvent (s-1) is within the above range, the resulting photosensitive resin composition exhibits a better elastic recovery rate.

Based on a combined usage of 100 parts by weight of the carboxylic acid group-containing ethylenically unsaturated compound (a-1) and the other copolymerizable ethylenically unsaturated compound (a-2), the usage of the alkyl glycol monoalkyl ether acetate solvent (s-2) is 40 to 360 parts by weight, preferably 40 to 320 parts by weight, and more preferably 40 to 300 parts by weight. When the usage of the alkyl glycol monoalkyl ether acetate solvent (s-2) is within the above range, the resulting photosensitive resin composition exhibits improved elastic recovery.

In one embodiment of the present invention, the first alkali-soluble resin (A-1) can be further reacted with a polycarboxylic acid or its anhydride (a-5).

The polycarboxylic acid or anhydride thereof (a-5) may be any of saturated or unsaturated polycarboxylic acids or anhydrides thereof, and specific examples thereof include malonic acid, succinic acid, succinic anhydride, glutaric acid, adipic acid, tetrahydrophthalic acid, tetrahydrophthalic anhydride, methyltetrahydrophthalic acid, methyltetrahydrophthalic anhydride, hexahydrophthalic acid, hexahydrophthalic anhydride, maleic acid, maleic anhydride, fumaric acid, succinic anhydride, malonic acid, succinic anhydride ... Examples of the present invention include dibasic acids or their anhydrides such as benzoic acid, itaconic acid, itaconic anhydride, citric acid, citric anhydride, 5-norbornene-2,3-dicarboxylic acid, 5-norbornene-2,3-dicarboxylic anhydride, methyl-5-norbornene-2,3-dicarboxylic anhydride, and phthalic anhydride; tribasic acids or their anhydrides such as trimellitic acid and trimellitic anhydride; and tetrabasic acids or their anhydrides such as pyromellitic acid and pyromellitic anhydride. Among these, dibasic acid anhydrides are preferably used.

Based on a combined usage amount of 1.0 mol of the carboxylic acid group-containing ethylenically unsaturated compound (a-1) and the other copolymerizable ethylenically unsaturated compound (a-2), the usage amount of the polycarboxylic acid or its anhydride (a-5) can be 0.1 mol to 0.93 mol, preferably 0.1 mol to 0.85 mol, and more preferably 0.1 mol to 0.8 mol. If the first alkali-soluble resin (A-1) further reacts with the polycarboxylic acid or its anhydride (a-5), the photosensitivity of the photosensitive resin composition can be enhanced.

The alkali-soluble resin (A-1) comprises a copolymer formed from the first mixture reacting with the epoxy-containing compound (a-3), and then reacting with the isocyanate-containing compound (a-4). The production method thereof will be described in detail below.

The copolymerization reaction of the copolymer formed from the first mixture can be carried out according to a free radical polymerization method well known in the art. For example, the first mixture comprising the carboxylic acid group-containing ethylenically unsaturated compound (a-1) and the other copolymerizable ethylenically unsaturated compound (a-2) can be dissolved in the polymerization solvent (s), and then a polymerization initiator can be added to the solution. The copolymerization reaction can be carried out at 50°C to 130°C for 1 to 20 hours.

The polymerization initiator that can be used in this copolymerization reaction is not particularly limited, and examples thereof include azobisisobutyronitrile, azobisisovaleronitrile, benzoyl peroxide, and tert-butylperoxy-2-ethylhexanoate. These initiators can be used alone or in combination of two or more. Based on a combined amount of 1.0 mol of the carboxylic acid group-containing ethylenically unsaturated compound (a-1) and other copolymerizable ethylenically unsaturated compounds (a-2), the amount of the polymerization initiator used is generally 0.0001 mol to 0.009 mol, preferably 0.0003 mol to 0.009 mol.

The copolymer formed from the first mixture is then reacted with the epoxy-containing compound (a-3), i.e., a ring-opening reaction is carried out. This can be carried out according to conventional methods. For example, after adding the copolymer and the epoxy-containing compound (a-3) to a reaction solvent, a catalyst can be added, and the ring-opening reaction can be carried out at a temperature of, for example, 50°C to 150°C, preferably 80°C to 130°C. Furthermore, in this reaction, even if the polymerization solvent (s) is included, there is no particular problem. Therefore, after the copolymerization reaction is completed, the polymerization solvent (s) can be directly reacted with the epoxy-containing compound (a-3) without removing it.

Furthermore, during the ring-opening reaction, a polymerization inhibitor may be added as needed to prevent gelation. The polymerization inhibitor is not particularly limited, and examples thereof include hydroquinone, methyl hydroquinone, and hydroquinone monomethyl ether. Furthermore, the catalyst is not particularly limited, and examples thereof include triethylamine, quaternary ammonium salts of triethylbenzylammonium chloride, phosphorus compounds of triphenylphosphine, and chromium chelate compounds.

Through the above-mentioned ring-opening reaction, a hydroxyl group derived from the epoxy group can be introduced into the side chain of the polymer, which can further react with the isocyanate group-containing compound (a-4).

The copolymer is reacted with the isocyanate-containing compound (a-4), i.e., an esterification reaction. Typically, the total molar number of hydroxyl groups generated by the ring-opening reaction is 1.0 mol. The isocyanate-containing compound (a-4) is used in an amount of 0.02 mol to 0.85 mol, preferably 0.05 mol to 0.8 mol.

The esterification reaction can also be carried out according to conventional methods. For example, after the ring-opening reaction, the isocyanate-containing compound (a-4) can be added to the reaction system and the reaction can be carried out at a temperature of, for example, 50°C to 150°C, preferably 50°C to 110°C. The reaction time can be appropriately selected and is generally 0.05 to 10 hours, preferably 0.1 to 7 hours.

The first alkali-soluble resin (A-1) has a weight average molecular weight of 1,000 to 50,000, preferably 3,000 to 40,000, as measured by gel permeation chromatography (GPC) and converted to polystyrene.

Optionally, the first alkali-soluble resin (A-1) may be further reacted with the polycarboxylic acid or its anhydride (a-5), for example, by reacting the remaining hydroxyl groups after the aforementioned esterification reaction with the polycarboxylic acid or its anhydride (a-5) to undergo a second esterification reaction. The reaction conditions may be similar to or the same as those of the aforementioned esterification reaction.

The alkali-soluble resin (A) according to the present invention may further comprise a second alkali-soluble resin (A-2) obtained by copolymerizing an ethylenically unsaturated monomer containing one or more carboxylic acid groups and another copolymerizable ethylenically unsaturated monomer. Based on 1.0 mol of the copolymerizable monomer, the second alkali-soluble resin (A-2) is obtained by copolymerizing 0.2 to 0.9 mol of the ethylenically unsaturated monomer containing one or more carboxylic acid groups and 0.1 to 0.8 mol of the other copolymerizable ethylenically unsaturated monomer.

The ethylenically unsaturated monomer containing one or more carboxylic acid groups can be used alone or in combination. Examples of the ethylenically unsaturated monomer containing carboxylic acid groups include, but are not limited to, unsaturated monocarboxylic acids such as acrylic acid, methacrylic acid (MAA), crotonic acid, α-chloroacrylic acid, ethylacrylic acid, cinnamic acid, 2-acryloylethoxysuccinate, or 2-methacryloyloxyethyl succinate monoester (HOMS); unsaturated dicarboxylic acids (anhydrides) such as maleic acid, maleic anhydride, fumaric acid, itaconic acid, itaconic anhydride, liconic acid, and liconic anhydride; and unsaturated polycarboxylic acids (anhydrides) having three or more carboxylic acid groups. Preferably, the carboxylic acid group-containing ethylenically unsaturated monomer is selected from acrylic acid, methacrylic acid, 2-acryloylethoxysuccinate, or 2-methacryloylethoxysuccinate. More preferably, the carboxylic acid group-containing ethylenically unsaturated monomer is selected from 2-acryloylethoxysuccinate or 2-methacryloylethoxysuccinate.

The other copolymerizable ethylenically unsaturated monomers can be used alone or in combination, and include but are not limited to aromatic vinyl compounds such as styrene (SM), α-methylstyrene, vinyltoluene, p-chlorostyrene, and methoxystyrene; N-phenylmaleimide (PMI), N-o-hydroxyphenylmaleimide, and N-hydroxyphenylmaleimide. Maleimines such as nitrogen-m-hydroxyphenylmaleimide, nitrogen-p-hydroxyphenylmaleimide, nitrogen-o-methylphenylmaleimide, nitrogen-m-methylphenylmaleimide, nitrogen-p-methylphenylmaleimide, nitrogen-o-methoxyphenylmaleimide, nitrogen-m-methoxyphenylmaleimide, nitrogen-p-methoxyphenylmaleimide, nitrogen-cyclohexylmaleimide, etc.; methyl acrylate (methyl acrylate, abbreviated as MA), methyl methacrylate, ethyl acrylate, ethyl methacrylate, n-propyl acrylate, n-propyl methacrylate, isopropyl acrylate, isopropyl methacrylate, n-butyl acrylate, n-butyl methacrylate, isobutyl acrylate, isobutyl methacrylate, 2-butyl acrylate, 2-butyl methacrylate, 3-butyl acrylate, 3-butyl methacrylate, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, 2-hydroxypropyl methacrylate, 3-hydroxypropyl acrylate, 3-hydroxypropyl methacrylate, 2-hydroxybutyl acrylate, 2-hydroxybutyl methacrylate, 3-hydroxybutyl acrylate, 3-hydroxybutyl methacrylate, 4-hydroxybutyl acrylate, 4-hydroxybutyl methacrylate, allyl acrylate, allyl methacrylate, benzyl acrylate, benzyl methacrylate (benzyl Unsaturated carboxylic acid esters such as dimethacrylate (BzMA), phenyl acrylate, phenyl methacrylate, triethylene glycol methoxy acrylate, triethylene glycol methoxy methacrylate, dodecyl methacrylate, tetradecyl methacrylate, hexadecyl methacrylate, octadecyl methacrylate, eicosyl methacrylate, behenyl methacrylate, dicyclopentenyloxyethyl acrylate (DCPOA); acrylate-nitrogen, nitrogen-dimethylaminoethyl ester, methacrylate-nitrogen, nitrogen-dimethylaminoethyl ester, acrylate-nitrogen, nitrogen-diethylaminopropyl ester, methacrylate-nitrogen, nitrogen-dimethylaminopropyl ester, acrylate-nitrogen, nitrogen-dibutylaminopropyl ester, nitrogen-isobutylaminoethyl methacrylate; unsaturated carboxylic acid glyoxypropyl esters such as glyoxypropyl acrylate and glyoxypropyl methacrylate; vinyl acetate, propionic acid Vinyl carboxylates such as vinyl esters and vinyl butyrate; unsaturated ethers such as vinyl methyl ether, vinyl ethyl ether, allyl epoxypropyl ether, and methallyl epoxypropyl ether; vinyl nitrile compounds such as acrylonitrile, methacrylonitrile, α-chloroacrylonitrile, and vinyl cyanide; unsaturated amides such as acrylamide, methacrylamide, α-chloroacrylamide, N-hydroxyethylacrylamide, and N-hydroxyethylmethacrylamide; aliphatic conjugated dienes such as 1,3-butadiene, isoprene, and chlorinated butadiene.

Preferably, the other copolymerizable ethylenically unsaturated monomer is selected from styrene, nitrogen-phenylmaleimide, methyl acrylate, methyl methacrylate, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, benzyl acrylate, benzyl methacrylate, biscyclopentenyloxyethyl acrylate, glycidyl methacrylate, 2-methacryloyloxyethyl isocyanate, or a combination thereof.

When preparing the second alkali-soluble resin (A-2), a solvent may be used. The solvent may be used alone or in combination, and the solvent includes but is not limited to (poly)alkylene glycol monoalkyl ethers such as ethylene glycol methyl ether, ethylene glycol ethyl ether, diethylene glycol methyl ether, diethylene glycol ethyl ether, diethylene glycol n-propyl ether, diethylene glycol n-butyl ether, triethylene glycol methyl ether, triethylene glycol ethyl ether, propylene glycol methyl ether, propylene glycol ethyl ether, dipropylene glycol methyl ether, dipropylene glycol ethyl ether, dipropylene glycol n-propyl ether, dipropylene glycol n-butyl ether, tripropylene glycol methyl ether, tripropylene glycol ethyl ether; ethylene glycol methyl ether acetate, ethylene glycol ethyl ether acetate, propylene glycol methyl ether acetate; acetate (abbreviated as PGMEA), propylene glycol ethyl ether acetate, etc.; other ethers such as diethylene glycol dimethyl ether, diethylene glycol methyl ethyl ether, diethylene glycol diethyl ether, tetrahydrofuran, etc.; ketones such as methyl ethyl ketone, cyclohexanone, 2-heptanone, 3-heptanone, etc.; alkyl lactates such as methyl 2-hydroxypropionate, ethyl 2-hydroxypropionate, etc.; methyl 2-hydroxy-2-methylpropionate, ethyl 2-hydroxy-2-methylpropionate, methyl 3-methoxypropionate, ethyl 3-methoxypropionate, methyl 3-ethoxypropionate, ethyl 3-ethoxypropionate (ethyl other esters such as ethyl 2-hydroxy-3-methylbutyrate, ethyl 3-ethoxypropionate (EEP), ethyl ethoxyacetate, ethyl hydroxyacetate, methyl 2-hydroxy-3-methylbutyrate, 3-methyl-3-methoxybutyl acetate, 3-methyl-3-methoxybutyl propionate, ethyl acetate, n-propyl acetate, isopropyl acetate, n-butyl acetate, isobutyl acetate, n-amyl acetate, isoamyl acetate, n-butyl propionate, ethyl butyrate, n-propyl butyrate, isopropyl butyrate, n-butyl butyrate, methyl pyruvate, ethyl pyruvate, n-propyl pyruvate, methyl acetylacetate, ethyl acetylacetate, and ethyl 2-methoxybutyrate; aromatic hydrocarbons such as toluene and xylene; amides such as nitrogen-methylpyrrolidone, nitrogen, nitrogen-dimethylformamide, or nitrogen, nitrogen-dimethylacetamide; and the like. Preferably, the solvent is selected from propylene glycol methyl ether acetate, ethyl 3-ethoxypropionate, or a combination thereof. The (poly)alkylene glycol monoalkyl ethers refer to alkylene glycol monoalkyl ethers or polyalkylene glycol monoalkyl ethers. The (poly)alkylene glycol monoalkyl ether acetates refer to alkylene glycol monoalkyl ether acetates or polyalkylene glycol monoalkyl ether acetates.

The initiator used in the preparation of the second alkali-soluble resin (A-2) is generally a free radical polymerization initiator, such as azo compounds such as 2,2'-azobisisobutyronitrile, 2,2'-azobis(2,4-dimethylvaleronitrile), 2,2'-azobis(4-methoxy-2,4-dimethylvaleronitrile), and 2,2'-azobis-2-methylbutyronitrile (AMBN); and peroxide compounds such as dibenzoyl peroxide.

The compound (B) having an ethylenically unsaturated group is selected from compounds having one ethylenically unsaturated group or compounds having two or more (including two) ethylenically unsaturated groups.

Specific examples of the compound having one ethylenically unsaturated group include (meth)acrylamide, (meth)acryloyl morpholine, 7-amino-3,7-dimethyloctyl (meth)acrylate, isobutoxymethyl (meth)acrylamide, isobornyloxyethyl (meth)acrylate, isobornyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, ethyl diethylene glycol (meth)acrylate, Trioctyl (meth)acrylamide, diacetone (meth)acrylamide, dimethylaminoethyl (meth)acrylate, dodecyl (meth)acrylate, dicyclopentenyloxyethyl (meth)acrylate, dicyclopentenyl (meth)acrylate, nitrogen, nitrogen-dimethyl (meth)acrylamide, tetrachlorophenyl (meth)acrylate, 2-tetrachlorophenoxyethyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate The compounds having one ethylenically unsaturated group may be used alone or in combination.

Specific examples of the compound having two or more (including two) ethylenically unsaturated groups include ethylene glycol di(meth)acrylate, dicyclopentenyl di(meth)acrylate, triethylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, tris(2-hydroxyethyl)isocyanate di(meth)acrylate, tris(2-hydroxyethyl)isocyanate tri(meth)acrylate, caprolactone-modified tris(2-hydroxyethyl)isocyanate tri(meth)acrylate, trihydroxymethylpropyl tri(meth)acrylate, ethylene oxide (EO)-modified tri(meth)acrylate, propylene oxide (EO)-modified tris(meth)acrylate, and propylene oxide (EO). PO) modified trihydroxymethylpropane tri(meth)acrylate, tripropylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, polyester di(meth)acrylate, polyethylene glycol di(meth)acrylate, dipentaerythritol hexa(meth)acrylate, dipentaerythritol penta(meth)acrylate, dipentaerythritol tetra(meth)acrylate, caprolactone-modified dipentaerythritol hexa(meth)acrylate, caprolactone-modified dipentaerythritol penta(meth)acrylate, ditrihydroxymethylpropane tetra(meth)acrylate (di(trimethylolpropane) tetra(meth)acrylate), bisphenol A di(meth)acrylate modified with ethylene oxide, bisphenol A di(meth)acrylate modified with propylene oxide, hydrogenated bisphenol A di(meth)acrylate modified with ethylene oxide, hydrogenated bisphenol A di(meth)acrylate modified with propylene oxide, glycerol tri(meth)acrylate modified with propylene oxide, bisphenol F di(meth)acrylate modified with ethylene oxide, novolac polyglycidyl ether (meth)acrylate, or the like, or combinations thereof. The above compounds having two or more (including two) ethylenically unsaturated groups may be used alone or in combination.

Specific examples of the compound (B) having an ethylenically unsaturated group include trihydroxymethylpropyl triacrylate, trihydroxymethylpropyl triacrylate modified with ethylene oxide, trihydroxymethylpropyl triacrylate modified with propylene oxide, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol hexaacrylate, dipentaerythritol pentaacrylate, dipentaerythritol tetraacrylate, caprolactone-modified dipentaerythritol hexaacrylate, ditrihydroxymethylpropyl tetraacrylate, propylene oxide-modified glycerol triacrylate, or the like, or a combination of the foregoing compounds.

The compound (B) having an ethylenically unsaturated group is preferably dipentaerythritol hexaacrylate, trihydroxymethylpropyl triacrylate, ditrihydroxymethylpropyl tetraacrylate, or a combination thereof.

Based on 100 parts by weight of the alkali-soluble resin (A), the compound (B) having an ethylenically unsaturated group is used in an amount of 30 to 300 parts by weight, preferably 50 to 250 parts by weight, and more preferably 50 to 200 parts by weight.

The photoinitiator (C) according to the present invention can be selected from a group consisting of a photoinitiator (C-1), a photoinitiator (C-2), and another photoinitiator (C-3).

The photoinitiator (C-1) is a compound represented by the following formula (I): Formula (I) In formula (I), A represents hydrogen, halogen, nitro, C ₁ -C ₂₀ linear or branched alkyl, C ₃ -C ₁₀ alkylcycloalkyl, C ₄ -C ₁₀ alkylcycloalkyl, C ₄ -C ₁₀ cycloalkylalkyl, 、 or , wherein C ₁ -C ₂₀ straight or branched alkyl, C ₃ -C ₁₀ alkylcycloalkyl, C ₄ -C ₁₀ alkylcycloalkyl, C ₄ -C ₁₀ cycloalkylalkyl, 、 or Any -CH ₂ - contained therein may be substituted by O, N, S or a carbonyl group; R ⁵ represents hydrogen, a halogen, a C ₁ -C ₂₀ straight or branched alkyl group, a C ₄ -C ₂₀ cycloalkylalkyl group or a C ₂ -C ₂₀ alkenyl group, wherein the -CH ₂ - contained in the C ₁ -C ₂₀ straight or branched alkyl group, the C ₄ -C ₂₀ cycloalkylalkyl group and the C ₂ -C ₂₀ alkenyl group may be substituted by O, N, S or a carbonyl group, and two R ⁵ groups may form a cyclic structure; R ⁶ represents a C ₁ -C ₂₀ straight or branched alkyl group, a C ₂ -C ₂₀ alkenyl group, a C ₃ -C ₂₀ cycloalkyl group, a C ₄ -C ₂₀ cycloalkylalkyl group, a C ₄ -C R ⁷ represents a C 1 -C ₂₀ straight or branched alkyl group, a C ₃ -C ₂₀ cycloalkyl group, a C ₄ -C ₂₀ cycloalkylalkyl group, a C 4 -C ₂₀ alkylcycloalkyl group, a C _{6 -C} 20 aryl group, a C 6 -C ₂₀ alkylaryl group, a group represented by the following formula (IA), a group represented by the following formula (IB) or a group represented by the following formula (IC), when R ⁷ represents a C ₁ -C ₂₀ straight or branched alkyl group, a C ₃ -C ₂₀ cycloalkyl group, a C ₄ -C ₂₀ cycloalkylalkyl group, a C _{4 -C 20} alkylcycloalkyl group, a C ₆ ^-C ₂₀ aryl group, a C 6 -C ₂₀ alkylaryl group, a group represented by the following formula (IA), a group represented by the following formula (IB) or a group represented by the _following formula (IC), When R ₇ is a C ₄ -C ₂₀ cycloalkyl group, a C _{4 -C 20 cycloalkylalkyl group, a C 4} -C ₂₀ alkylcycloalkyl group, a C ₆ -C ₂₀ aryl group, or a C ₆ -C ₂₀ alkylaryl group, one or more hydrogen groups in these groups may be independently replaced by an alkyl group, a halogen group, a hydroxyl group, or a nitro group, and the -CH ₂ - group in R ⁷ may be replaced by an O, a N, a S, or a carbonyl group; R ⁶ and R ⁷ may form a cyclic structure; Formula (IA): In formula (IA), m represents an integer of 0 or 1, R ¹¹ represents hydrogen, a C ₁ -C ₈ alkyl group, or a phenyl group, and R ¹² , R ¹³ , and R ¹⁴ each independently represent hydrogen or a C ₁ -C ₄ alkyl group; Formula (IB) In formula (IB), p is an integer from 0 to 3; Formula (IC) In formula (IC), R ^{1 5} represents hydrogen, C ₁ -C ₈ alkyl, or phenyl; Ar is substituted or unsubstituted phenyl, naphthyl, furyl, thienyl, or pyridyl; R ⁸ represents N-morpholinyl ( ）、N-piperidinyl ( ), N-pyrrolyl ( ) or N-dialkyl (N(R ²¹ ) ₂ , wherein R ²¹ represents an alkyl group), wherein one or more hydrogen atoms in these groups may be substituted by a halogen or a hydroxyl group; R ⁹ and R ^9' each independently represent a C ₁ -C ₂₀ linear or branched alkyl group, a C ₄ -C ₂₀ cycloalkyl group, a C ₂ -C ₂₀ alkenyl group, a C ₆ -C ₂₀ aryl group, or a C ₆ -C ₂₀ alkylaryl group, wherein one or more hydrogen atoms in these groups may be substituted by an alkyl group, a halogen, a hydroxyl group, or a nitro group, and the -CH ₂ - in these groups may be substituted by -O-; or R ⁹ and R ^9' may be linked to each other or form a five-membered or six-membered ring through -O-, -S-, or -NH-; R ¹⁰ represents a C ₁ -C ₂₀ straight or branched alkyl, C ₄ -C ₂₀ cycloalkyl, C ₄ -C ₂₀ alkylcycloalkyl, C ₂ -C ₂₀ alkenyl, C ₆ -C ₂₀ aryl or C ₆ -C ₂₀ alkylaryl, wherein -CH ₂ - in these groups may be substituted by -O- or -S-, and one or more hydrogen atoms in these groups may be independently substituted by an alkyl group, a halogen, a nitro group, a cyano group, SR ¹⁶ or OR ¹⁷ ; R ¹⁶ and R ¹⁷ each independently represent hydrogen, or a C ₁ -C ₂₀ straight or branched alkyl group. In addition, in formula (I), A preferably represents hydrogen, methyl, methoxy, chlorine, nitro, or N-morpholinyl, wherein R ¹⁰ is preferably phenyl, phenyl substituted by one or more methyl groups, phenyl substituted by nitro groups, or , more preferably represents hydrogen, methyl, nitro, phenyl substituted by one or more methyl groups, or N-morpholinyl, wherein * represents the bonding position.

In formula (I), R ⁵ preferably represents hydrogen, methyl, propyl, butyl or allyl (-CH ₂ CH=CH ₂ ) groups, and more preferably represents hydrogen, methyl, butyl or allyl.

In formula (I), R ⁶ preferably represents a methyl group or an ethyl group.

In formula (I), R ⁷ preferably represents a methyl group, an ethyl group or a benzyl group, and more preferably represents a methyl group or a benzyl group.

In formula (I), R ⁸ is preferably N-morpholinyl, N-piperidinyl, -N(CH ₃ ) ₂ , -N(CH ₂ CH ₂ CH ₃ ) ₂ or N-pyrrolyl, more preferably N-morpholinyl, -N(CH ₃ ) ₂ , N-pyrrolyl or N-piperidinyl, wherein * indicates the bonding position.

Specific examples of the photoinitiator (C-1) include compounds represented by the following formulas (I-1) to (I-35), or combinations of these compounds. Formula (I-1) Formula (I-2) Formula (I-3) Formula (I-4) Formula (I-5) Formula (I-6) Formula (I-7) Formula (I-8) Formula (I-9) Formula (I-10) Formula (I-11) Formula (I-12) Formula (I-13) Formula (I-14) Formula (I-15) Formula (I-16) Formula (I-17) Formula (I-18) Formula (I-19) Formula (I-20) Formula (I-21) Formula (I-22) Formula (I-23) Formula (I-24) Formula (I-25) Formula (I-26) Formula (I-27) Formula (I-28) Formula (I-29) Formula (I-30) Formula (I-31) Formula (I-32) Formula (I-33) Formula (I-34) Formula (I-35)

Specific examples of the photoinitiator (C-1) preferably include a compound represented by formula (I-1), a compound represented by formula (I-5), a compound represented by formula (I-11), a compound represented by formula (I-14), a compound represented by formula (I-17), a compound represented by formula (I-19), a compound represented by formula (I-28), a compound represented by formula (I-35), or a combination of these compounds.

The photoinitiator (C-2) is a compound represented by the following formula (II): Formula (II) In formula (II), Ar ₁ represents an azimuthal aryl group or an azimuthal heteroaryl group, wherein the azimuthal aryl group or the azimuthal heteroaryl group is a cyclic structure formed by two adjacent atoms with Y ₁ and a carbonyl group, and the substituents on the remaining atoms are independently selected from hydrogen; halogen; C ₁ -C ₁₂ alkyl; C ₅ -C ₇ cycloalkyl; C ₁ -C ₄ alkyl substituted with a C ₅ -C ₇ cycloalkyl; phenyl; phenyl substituted with one or more C ₁ -C ₄ alkyl, carboxyl, C ₁ -C ₁₂ alkylacyl, C ₁ -C ₁₂ arylacyl, heteroarylacyl, JT ₄ , phenyl, halogen or CN; C ₁ -C ₄ alkylbenzyloxy; Substituted C ₁ -C ₄ alkoxy, C ₁ -C ₃ alkylenedioxy; ; C ₁ -C ₁₂ alkylthio; C ₁ -C ₄ alkylphenylthio; a substituted C ₁ -C ₄ alkylthio group; CN; a carboxyl group; a C ₁ -C ₁₂ alkoxymethyl group; an aryl acyl group; a heteroaryl acyl group, and JT ₅ ; or a cyclic structure is formed between two adjacent substituents in the above substituents of Ar ₁ or between the substituent and Ar ₁ via a single bond, a carbon atom, or a carbonyl group; wherein, in JT ₄ and JT ₅ , J is selected from the group consisting of O, S, and NT ₆ ; Y ₁ is selected from the group consisting of O, S, NT ₇ , BT ₇ , CT ₂ T ₃ , SiT ₂ T ₃ , S═O, and C═O; T ₁ represents hydrogen, a C ₁ -C ₁₈ alkyl group, or a C ₁ -C ₁₈ alkoxy group; or T ₁ represents a halogenated or C ₁ -C C 2 -C ₁₈ alkyl substituted with a C ₅ -C ₇ cycloalkyl, heterocycloalkyl, phenyl, heteroaryl, CN, a C ₁ -C ₄ alkanoyloxy or aryloxy group and/or inserted with a C ₅ -C ₇ cycloalkylene, phenylene, O, S or NT ₄ ; C ₂ -C ₁₈ alkenyl; C ₂ -C ₁₈ alkenyl substituted with one or more halogens, a C ₁ -C ₄ alkyl, a C ₅ -C ₇ cycloalkyl, heterocycloalkyl, phenyl, heteroaryl, CN, a C ₁ -C ₄ alkanoyloxy or aryloxy group and/or inserted with a C _{5 -C 7} cycloalkylene, phenylene, O, S or NT ₄ , or _both of the above; or T ₁ represents C ₅ -C or _T1 represents a phenyl group, or a phenyl group substituted _{by one or more C1-C4 alkyl groups} , _C1 - _{C4 alkoxy} groups, a phenyl group, a halogen group or CN; or T1 represents a naphthyl group, a _benzoyl group or a phenoxycarbonyl group, wherein the phenyl group of the benzoyl group and the phenoxycarbonyl group is arbitrarily substituted by one or more halogen groups, _T4 , a _C5 - _C6 cycloalkyl group, CN, OH or _JT4 ; _T2 and _T3 each independently represent hydrogen, a C1- _C18 alkyl _group , a C1- _C5 alkyl _group substituted by a carboxyl group, a C1- _C5 alkyl group substituted by a _C1 - _C4 alkoxyacyl group or a C1- _C5 alkyl group substituted by a _C1 -C4 alkoxyacyl group or a C1 _{- C5} alkyl group substituted by a substituted C ₁ -C ₄ alkyl; or T ₂ and T ₃ each independently represent a C 2 -C 18 alkyl group substituted by one or more halogens, C ₁ -C ₄ alkyl, C ₅ -C ₇ cycloalkyl, heterocycloalkyl, phenyl, heteroaryl, CN, C ₁ -C ₄ alkanoyloxy, or aryloxy groups, or a C ₂ -C ₁₈ alkyl group inserted by a C ₅ -C ₇ cycloalkylene, phenylene, O, S, or NT ₄ , or both of the above; or T ₂ and T ₃ each independently represent a C _{5 -C 7} cycloalkyl group, or _a C ₅ -C ₇ cycloalkyl group substituted by one or more C ₁ -C ₄ alkyl, phenyl, halogen, or CN; or T ₂ and T _each independently represents a phenyl group, or a C2- _C4 alkyl group, a _C1 - _C4 alkoxy group, a carboxyl group, a C1- _C12 alkylacyl group, a C5- _C6 cycloalkylcarbonyl group, or a _C5 - _C6 cycloalkyl group, a C2-C4 alkylacyl group, an arylacyl group, JT4, a phenyl group, a halogen group, or a phenyl group substituted with one or more C1-C4 alkyl groups, C1-C4 alkoxy groups, carboxyl groups, _C1 - _C12 alkylacyl groups, C5-C6 cycloalkylcarbonyl groups, or _C5 - _C6 cycloalkyl groups; or T2 and T3 each independently represent a phenyl group, or a _C2 -C4 alkylacyl group, an arylacyl group, a phenyl group, a halogen group, or a CN-substituted phenyl group; or _T2 and _T3 each independently represent a phenyl group, or a C2-C4 alkyl group, a _C1 -C4 alkoxy group, a carboxyl group, a C1-C12 alkylacyl group, a C5-C6 cycloalkylcarbonyl group, or a C5- _C6 cycloalkyl group; or _T2 and T3 each independently represent a phenyl group, or a C2-C4 alkylacyl group, an arylacyl group, a phenyl group, a halogen group, or a CN-substituted phenyl group; or T2 and T3 each independently represent a phenyl group, or a C2-C4 alkyl group, a C1-C18 alkylacyl group, a _C1 -C18 cycloalkylcarbonyl group, or a C5-C6 cycloalkyl group; _or T2 and T3 each independently represent a phenyl group, or a C2- _{C4 alkylacyl group, a C1-C18} cycloalkylcarbonyl group, a _C1 - _C18 cycloalkylcarbonyl group, or a C5- _C6 cycloalkyl group; or T2 and _{T3 each} independently represent a -C ₄ alkoxy acyl substituted C ₁ -C ₅ alkyl or or T ₅ represents a C ₂ -C ₁₈ alkyl group substituted by one or more halogens, C ₁ -C ₄ alkyl groups, C ₅ -C ₇ cycloalkyl groups, heterocycloalkyl groups, phenyl groups, heteroaryl groups, CN, C ₁ -C ₄ alkanoyloxy groups or aryloxy groups, or a C ₂ -C ₁₈ alkyl group inserted by a C ₅ -C ₇ cycloalkylene group, a phenylene group, O, S or NT ₄ , or both of the above; or T ₅ represents a C ₅ -C ₇ cycloalkyl group, or a C ₅ -C ₇ cycloalkyl group substituted by one or more C ₁ -C ₄ alkyl groups, phenyl groups, halogens or CN; or T ₅ represents a phenyl group, or a C ₅ -C ₇ cycloalkyl group inserted by one or more C ₁ -C ₁₂ alkyl groups, carboxyl groups, C ₁ -C ₁₂ -C alkylacyl, a C ₂ -C ₁₂ alkylacyl group inserted by a phenylene group, O, S or NT ₄ , a C ₅ -C ₆ cycloalkylcarbonyl group, a C ₂ -C ₄ alkylacyl group substituted by a C ₅ -C ₆ cycloalkyl group, an arylacyl group, a heteroarylacyl group, a phenyl group substituted by the above substituents such as JT ₄ , phenyl, halogen, CN or NO ₂ , wherein the arylacyl group is a benzoyl group, or a benzoyl group substituted by one or more halogens, C ₁ -C ₄ alkyl groups or C ₁ -C ₄ alkoxy groups; or T ₅ represents a C ₁ -C ₄ alkylacyl group, a C ₁ -C ₄ , a conjugated alkylene group, a benzoyl group or a phenoxycarbonyl group, wherein the phenyl group in the benzoyl group and the phenoxycarbonyl group may be arbitrarily substituted with one or more halogens, T ₄ , a cyclopentyl group, a cyclohexyl group, CN, OH or JT ₄ ; or T ₅ forms a cyclic structure with the aromatic ring in Ar ₁ through a single bond, a carbon atom or a carbonyl group; T ₆ and T ₇ each independently represent hydrogen, a C ₁ -C ₁₈ alkyl group, a C 1 -C 5 alkyl group substituted with a C ₁ -C ₄ alkoxyacyl group or a C 1 -C 5 alkyl group substituted with a C ₁ -C ₄ alkoxyacyl group substituted C ₁ -C ₄ alkyl; or T ₆ and T ₇ each independently represent a C 2 -C 18 alkyl group substituted by one or more halogens, C ₁ -C ₄ alkyl, C ₅ -C ₇ cycloalkyl, heterocycloalkyl, phenyl, heteroaryl, CN, C ₁ -C ₄ alkanoyloxy or aryloxy groups, a C ₂ -C ₁₈ alkyl group inserted by a C 5 -C 7 cycloalkylene, phenylene, O, S or NT ₄ , or both of the above; or T ₆ and T ₇ each independently represent a C ₅ -C ₇ cycloalkyl group, or a C ₅ -C ₇ cycloalkyl group substituted by one or more C ₁ -C ₄ alkyl, phenyl, halogen or CN; or T ₆ and T ₇ each independently represent a phenyl group, or a C ₅ -C ₇ cycloalkyl group inserted by one or more C ₁ -C ₄ alkyl, phenyl, halogen or CN. wherein Y is a _C1 - _C4 alkyl group, a carboxyl group, a _C1 - _C12 alkylacyl group, a _C5 - _C6 cycloalkylcarbonyl group, or a _C5 - _C6 cycloalkyl _{-substituted C2-C4 alkylacyl} group, an arylacyl group, _JT4 , a phenyl group, a halogen- or CN-substituted phenyl group; or each of _T6 forms a cyclic structure with the aromatic ring in _Ar1 via a single bond, a carbon atom, or a carbonyl group; wherein when _Ar1 is a substituted carbazolyl group, _Y1 is not C, O, S, or N- _T7 .

In formula (II), Ar ₁ preferably represents a group represented by the following formula (II-A): Formula (II-A) T ₈ , T ₉ , T ₁₀ and T ₁₁ each independently represent hydrogen; or T ₈ , T ₉ , T ₁₀ and T ₁₁ each independently represent a C ₁ -C ₄ alkoxy group substituted with one or more C ₁ -C ₁₂ alkoxy groups, C ₁ -C ₄ alkylbenzyloxy groups, a substituted C ₁ -C ₄ alkoxy group; or T ₈ , T ₉ , T ₁₀ , and T ₁₁ each independently represent a phenoxy group substituted with one or more C ₁ -C ₄ alkyl groups; a phenoxy group substituted with a C ₁ -C ₈ alkylacyl group, a C ₅ -C ₆ cycloalkylacyl group, an arylacyl group, or a heteroarylacyl group; a C ₁ -C ₄ alkylacylphenoxy group substituted with a C ₅ -C ₆ cycloalkyl group; or a C ₁ -C ₃ alkylenedioxy group; ; C ₁ -C ₁₂ alkylthio; Substituted C ₁ -C ₄ alkylthio; C ₁ -C ₄ alkylphenylthio; substituted C ₁ -C ₄ alkylphenylthio; or T ₈ , T ₉ , T ₁₀ and T ₁₁ each independently represent a phenylthio group substituted with a C ₁ -C ₈ alkylacyl group, a C ₅ -C ₆ cycloalkylacyl group, an arylacyl group, a heteroarylacyl group, or a C ₁ -C ₄ alkylacylphenylthio group substituted with a C ₅ -C ₆ cycloalkyl group; Y ₁ preferably represents CH ₂ , CHCH ₃ or C(CH ₃ ) ₂ ; T ₁ preferably represents methyl, ethyl, phenyl, 2-methylphenyl, 3-methylphenyl, 2,4,6-trimethylphenyl or 2,6-dimethoxyphenyl; * represents a bonding position.

It is noteworthy that among the substituents of Ar ₁ , it is preferred that at least one substituent is located in the para position relative to the carbonyl group connected to Ar ₁ .

Specific examples of the photoinitiator (C-1) include compounds represented by the following formulas (II-1) to (II-28), or combinations of these compounds: Formula (II-1) Formula (II-2) Formula (II-3) Formula (II-4) Formula (II-5) Formula (II-6) Formula (II-7) Formula (II-8) Formula (II-9) Formula (II-10) Formula (II-11) Formula (II-12) Formula (II-13) Formula (II-14) Formula (II-15) Formula (II-16) Formula (II-17) Formula (II-18) Formula (II-19) Formula (II-20) Formula (II-21) Formula (II-22) Formula (II-23) Formula (II-24) Formula (II-25) Formula (II-26) Formula (II-27) Formula (II-28)

Specific examples of the photoinitiator (C-2) preferably include a compound represented by formula (II-2), a compound represented by formula (II-6), a compound represented by formula (II-11), a compound represented by formula (II-17), a compound represented by formula (II-24), a compound represented by formula (II-28), or a combination of these compounds.

Specific examples of other photoinitiators (C-3) include, but are not limited to, O-acyl oxime compounds, triazine benzene compounds, acetophenone compounds, diimidazole compounds, benzophenone compounds, α-diketone compounds, ketoalcohol compounds, ketoalcohol ether compounds, acylphosphine oxide compounds, quinone compounds, halogen-containing compounds, peroxides, or combinations thereof.

Specific examples of the above-mentioned O-acyl oxime compounds include 1-[4-(phenylthio)phenyl]-propane-3-cyclopentane-1,2-dione 2-(O-phenylyl oxime), 1-[4-(phenylthio)phenyl]-heptane-1,2-dione 2-(O-phenylyl oxime), 1-[4-(phenylthio)phenyl]-octane-1,2-dione 2-(O-phenylyl oxime), ethane ketone, 1-[9-ethyl-6-(2-methylbenzyl)-9-hydro-oxazole-3-substituted]-, 1-(oxy-acetyl oxime), 1,2-butanedione-1-[4-(methylthio)phenyl] 2-(O-acetyl oxime), or combinations thereof.

Specific examples of O-acyl oxime compounds preferably include 1-[4-(phenylthio)phenyl]-heptane-1,2-dione 2-(O-phenylacyl oxime), 1-[4-(phenylthio)phenyl]-octane-1,2-dione 2-(O-phenylacyl oxime), or combinations thereof. These O-acyl oxime compounds can be used individually or in combination, depending on actual needs.

Specific examples of triazine compounds may include, but are not limited to, vinyl-halogenated methyl-s-triazine compounds, 2-(naphtho-1-substituted)-4,6-bis-halogenated methyl-s-triazine compounds, 4-(p-aminophenyl)-2,6-bis-halogenated methyl-s-triazine compounds, or combinations thereof.

Specific examples of the vinyl-halogenated methyl-s-triazine compound include 2,4-bis(trichloromethyl)-6-p-methoxyphenyl-s-triazine, 2,4-bis(trichloromethyl)-3-(1-p-dimethylaminophenyl-1,3-butene)-s-triazine, 2-trichloromethyl-3-amino-6-p-methoxyphenyl-s-triazine, or a combination thereof.

Specific examples of the above-mentioned 2-(naphtho-1-substituted)-4,6-bis-halogenated methyl-s-triazine compounds include 2-(naphtho-1-substituted)-4,6-bis-trichloromethyl-s-triazine, 2-(4-methoxy-naphtho-1-substituted)-4,6-bis-trichloromethyl-s-triazine, 2-(4-ethoxy-naphtho-1-substituted)-4,6-bis-trichloromethyl-s-triazine, 2-(4-Butoxy-naphtho-1-substituted)-4,6-bis-trichloromethyl-s-triazine, 2-[4-(2-methoxyethyl)-naphtho-1-substituted]-4,6-bis-trichloromethyl-s-triazine, 2-[4-(2-ethoxyethyl)-naphtho-1-substituted]-4,6-bis-trichloromethyl-s-triazine, 2-[4-(2-butoxyethyl)-naphtho-1-substituted] -4,6-bis-trichloromethyl-s-triazine, 2-(2-methoxy-naphtho-1-substituted)-4,6-bis-trichloromethyl-s-triazine, 2-(6-methoxy-5-methyl-naphtho-2-substituted)-4,6-bis-trichloromethyl-s-triazine, 2-(6-methoxy-naphtho-2-substituted)-4,6-bis-trichloromethyl-s-triazine, 2-(5-methoxy-naphtho- 1-substituted)-4,6-bis-trichloromethyl-s-triazine, 2-(4,7-dimethoxy-naphtho-1-substituted)-4,6-bis-trichloromethyl-s-triazine, 2-(6-ethoxy-naphtho-2-substituted)-4,6-bis-trichloromethyl-s-triazine, 2-(4,5-dimethoxy-naphtho-1-substituted)-4,6-bis-trichloromethyl-s-triazine, or a combination thereof.

Specific examples of the aforementioned 4-(p-aminophenyl)-2,6-di-halogenated methyl-s-triazine compounds include 4-[p-N,N-bis(ethoxycarbonylmethyl)aminophenyl]-2,6-bis(trichloromethyl)-s-triazine, 4-[o-methyl-p-N,N-bis(ethoxycarbonylmethyl)aminophenyl]-2,6-bis(trichloromethyl)-s-triazine, 4-[p-N,N-bis(chloroethyl)aminophenyl]-2,6-bis(trichloromethyl)-s-triazine, 4-[o-methyl-p-N,N-bis(chloroethyl)aminophenyl]-2,6-bis(trichloromethyl)-s-triazine, phenyl]-2,6-bis(trichloromethyl)-s-triazine, 4-(p-N-chloroethylaminophenyl)-2,6-bis(trichloromethyl)-s-triazine, 4-(p-N-ethoxycarbonylmethylaminophenyl)-2,6-bis(trichloromethyl)-s-triazine, 4-[p-N,N-di(phenyl)aminophenyl]-2,6-bis(trichloromethyl)-s-triazine, 4-(p-N-chloroethylcarbonylaminophenyl)-2,6-bis(trichloromethyl)-s-triazine, 4-[p-N,N-di(phenyl)aminophenyl]-2,6-bis(trichloromethyl)-s-triazine, 4-(p-N-chloroethylcarbonylaminophenyl)-2,6-bis(trichloromethyl)-s-triazine, 4-[p-N-(p-methoxyphenyl)carbonylaminophenyl] phenyl]-2,6-bis(trichloromethyl)-s-triazine, 4-[m-N,N-bis(ethoxycarbonylmethyl)aminophenyl]-2,6-bis(trichloromethyl)-s-triazine, 4-[m-bromo-p-N,N-bis(ethoxycarbonylmethyl)aminophenyl]-2,6-bis(trichloromethyl)-s-triazine, 4-[m-chloro-p-N,N-bis(ethoxycarbonylmethyl)aminophenyl]-2,6-bis(trichloromethyl)-s-triazine, 4-[m-fluoro-p-N,N-bis(ethoxycarbonylmethyl)aminophenyl]-2,6 -Bis(trichloromethyl)-s-triazine, 4-[o-bromo-p-N,N-bis(ethoxycarbonylmethyl)aminophenyl]-2,6-bis(trichloromethyl)-s-triazine, 4-[o-chloro-p-N,N-bis(ethoxycarbonylmethyl)aminophenyl]-2,6-bis(trichloromethyl)-s-triazine, 4-[o-fluoro-p-N,N-bis(ethoxycarbonylmethyl)aminophenyl]-2,6-bis(trichloromethyl)-s-triazine, 4-[o-bromo-p-N,N-bis(chloroethyl)aminophenyl]-2,6-bis(trichloromethyl) -s-Triazine, 4-[o-chloro-p-N,N-bis(chloroethyl)aminophenyl]-2,6-bis(trichloromethyl)-s-triazine, 4-[o-fluoro-p-N,N-bis(chloroethyl)aminophenyl]-2,6-bis(trichloromethyl)-s-triazine, 4-[m-bromo-p-N,N-bis(chloroethyl)aminophenyl]-2,6-bis(trichloromethyl)-s-triazine, 4-[m-chloro-p-N,N-bis(chloroethyl)aminophenyl]-2,6-bis(trichloromethyl)-s-triazine, 4-[m-fluoro-p-N ,N-bis(chloroethyl)aminophenyl]-2,6-bis(trichloromethyl)-s-triazine, 4-(m-bromo-p-N-ethoxycarbonylmethylaminophenyl)-2,6-bis(trichloromethyl)-s-triazine, 4-(m-chloro-p-N-ethoxycarbonylmethylaminophenyl)-2,6-bis(trichloromethyl)-s-triazine, 4-(m-fluoro-p-N-ethoxycarbonylmethylaminophenyl)-2,6-bis(trichloromethyl)-s-triazine, 4-(o-bromo-p-N-ethoxycarbonylmethylaminophenyl)-2,6-bis(trichloromethyl)-s-triazine methyl)-s-triazine, 4-(o-chloro-p-N-ethoxycarbonylmethylaminophenyl)-2,6-bis(trichloromethyl)-s-triazine, 4-(o-fluoro-p-N-ethoxycarbonylmethylaminophenyl)-2,6-bis(trichloromethyl)-s-triazine, 4-(m-bromo-p-N-chloroethylaminophenyl)-2,6-bis(trichloromethyl)-s-triazine, 4-(m-chloro-p-N-chloroethylaminophenyl)-2,6-bis(trichloromethyl)-s-triazine, 4-(m-fluoro-p-N-chloroethylaminophenyl)- 2,6-bis(trichloromethyl)-s-triazine, 4-(o-bromo-p-N-chloroethylaminophenyl)-2,6-bis(trichloromethyl)-s-triazine, 4-(o-chloro-p-N-chloroethylaminophenyl)-2,6-bis(trichloromethyl)-s-triazine, 4-(o-fluoro-p-N-chloroethylaminophenyl)-2,6-bis(trichloromethyl)-s-triazine, 2,4-bis(trichloromethyl)-6-[3-bromo-4-[N,N-bis(ethoxycarbonylmethyl)amino]phenyl]-1,3,5-triazine, or a combination thereof.

Specific examples of the aforementioned triazine compounds preferably include 4-[m-bromo-p-N,N-bis(ethoxycarbonylmethyl)aminophenyl]-2,6-bis(trichloromethyl)-s-triazine, 2,4-bis(trichloromethyl)-6-p-methoxyphenyl-s-triazine, or combinations thereof. The aforementioned triazine compounds may be used alone or in combination.

Specific examples of the aforementioned acetophenone compounds include p-dimethylaminoacetophenone, α,α'-dimethoxyazyzoacetophenone, 2,2'-dimethyl-2-phenylacetophenone, p-methoxyacetophenone, 2-methyl-1-(4-methylthiophenyl)-2-morpholino-1-propanone, 2-benzyl-2-N,N-dimethylamine-1-(4-morpholinophenyl)-1-butanone, or combinations thereof. The aforementioned acetophenone compounds are preferably 2-methyl-1-(4-methylthiophenyl)-2-morpholino-1-propanone, 2-benzyl-2-N,N-dimethylamine-1-(4-morpholinophenyl)-1-butanone, or combinations thereof. The aforementioned acetophenone compounds can be used alone or in combination.

Specific examples of the above-mentioned diimidazole compounds include 2,2'-bis(o-chlorophenyl)-4,4',5,5'-tetraphenyldiimidazole, 2,2'-bis(o-fluorophenyl)-4,4',5,5'-tetraphenyldiimidazole, 2,2'-bis(o-methylphenyl)-4,4',5,5'-tetraphenyldiimidazole, 2,2'-bis(o-methoxyphenyl)-4,4',5,5'-tetraphenyldiimidazole, 2,2'-bis(o-ethylphenyl) -4,4',5,5'-tetraphenyldiimidazole, 2,2'-bis(p-methoxyphenyl)-4,4',5,5'-tetraphenyldiimidazole, 2,2'-bis(2,2',4,4'-tetramethoxyphenyl)-4,4',5,5'-tetraphenyldiimidazole, 2,2'-bis(2-chlorophenyl)-4,4',5,5'-tetraphenyldiimidazole, 2,2'-bis(2,4-dichlorophenyl)-4,4',5,5'-tetraphenyldiimidazole. The aforementioned diimidazole compound is preferably 2,2'-bis(2,4-dichlorophenyl)-4,4',5,5'-tetraphenyldiimidazole, or a combination thereof. The aforementioned diimidazole compounds can be used alone or in combination, depending on actual needs.

Specific examples of the aforementioned benzophenone compounds include thiathione, 2,4-diethylthiathione, thiathione-4-sulfone, benzophenone, 4,4'-bis(dimethylamino)benzophenone, 4,4'-bis(diethylamino)benzophenone, or combinations thereof. The aforementioned benzophenone compound is preferably 4,4'-bis(diethylamino)benzophenone. The aforementioned benzophenone compounds can be used individually or in combination, depending on actual needs.

Specific examples of the aforementioned α-diketone compounds include benzoyl, acetyl, or a combination thereof.

Specific examples of the ketone alcohol compounds include benzoyl ketone. Specific examples of the ketone alcohol ether compounds include benzoyl ketone methyl ether, benzoyl ketone ethyl ether, benzoyl ketone isopropyl ether, or a combination thereof.

Specific examples of the aforementioned acylphosphine oxide compounds include 2,4,6-trimethylphenyldiphenylphosphine oxide, bis-(2,6-dimethoxyphenyl)-2,4,4-trimethylphenylphosphine oxide, or a combination thereof.

Specific examples of the quinone compounds include anthraquinone, 1,4-naphthoquinone, or a combination thereof.

Specific examples of the halogen-containing compounds include phenylmethyl chloride, tribromomethylphenylsulfonium, tris(trichloromethyl)-s-triazine, or a combination thereof.

Specific examples of the peroxide include di-t-butyl peroxide, or a combination thereof.

The aforementioned α-diketone compounds, ketoalcohol compounds, ketoalcohol ether compounds, phosphine oxide compounds, quinone compounds, halogen-containing compounds, peroxides, etc. can be used alone or in combination, depending on actual needs.

Specific examples of other photoinitiators (C-3) preferably include 1-[4-(phenylthio)phenyl]-octane-1,2-dione 2-(O-phenylyl oxime) (e.g., trade name OXE-01, manufactured by Ciba Specialty Chemicals, Ltd., with the structure represented by formula (IV)), 2-methyl-1-(4-methylthiophenyl)-2-morpholino-1-propanone (trade name Irgacure 907, manufactured by Ciba Specialty Chemicals, Ltd.), or a combination thereof. Formula (IV)

Based on 100 parts by weight of the alkali-soluble resin (A), the amount of the photoinitiator (C) is 10 to 100 parts by weight, preferably 10 to 80 parts by weight, and more preferably 10 to 75 parts by weight.

The organic solvent (D) is an organic solvent that can dissolve the alkali-soluble resin (A), the compound containing an ethylenically unsaturated group (B), the photoinitiator (C), and the optional additive (E) without reacting with the above components and preferably has appropriate volatility.

Specific examples of the organic solvent (D) include: alkyl glycol monoalkyl ether compounds, alkyl glycol monoalkyl ether acetate compounds, diethylene glycol alkyl ether, other ether compounds, ketone compounds, lactic acid alkyl ester compounds, other ester compounds, aromatic hydrocarbon compounds, carboxylic acid amide compounds, or combinations thereof.

Specific examples of alkyl glycol monoalkyl ether compounds include: ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, diethylene glycol monoethyl ether, diethylene glycol mono-n-propyl ether, diethylene glycol mono-n-butyl ether, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol mono-n-propyl ether, dipropylene glycol mono-n-butyl ether, tripropylene glycol monomethyl ether or tripropylene glycol monoethyl ether or their analogs, or combinations thereof.

Specific examples of alkyl glycol monoalkyl ether acetate compounds include ethylene glycol methyl ether acetate, ethylene glycol ethyl ether acetate, propylene glycol methyl ether acetate, propylene glycol ethyl ether acetate, or their analogs, or combinations thereof.

Specific examples of diethylene glycol alkyl ethers include diethylene glycol dimethyl ether, diethylene glycol methyl ethyl ether, diethylene glycol diethyl ether, or the like, or a combination thereof.

Specific examples of other ether compounds include tetrahydrofuran or its analogs.

Specific examples of ketone compounds include methyl ethyl ketone, cyclohexanone, 2-heptanone, 3-heptanone, diacetone alcohol or their analogs, or combinations thereof.

Specific examples of alkyl lactate compounds include methyl lactate, ethyl lactate or their analogs, or combinations thereof.

Specific examples of other ester compounds include methyl 2-hydroxy-2-methylpropionate, ethyl 2-hydroxy-2-methylpropionate, methyl 3-methoxypropionate, ethyl 3-methoxypropionate, methyl 3-ethoxypropionate, ethyl 3-ethoxypropionate, ethyl ethoxyacetate, ethyl hydroxyacetate, methyl 2-hydroxy-3-methylbutanoate, 3-methyl-3-methoxybutyl acetate, 3-methyl-3-methoxybutyl propionate, ethyl acetate, n-propyl acetate, isopropyl acetate, Ester, n-butyl acetate, isobutyl acetate, n-amyl acetate, isoamyl acetate, n-butyl propionate, ethyl butyrate, n-propyl butyrate, isopropyl butyrate, n-butyl butyrate, methyl pyruvate, ethyl pyruvate, n-propyl pyruvate, methyl acetylacetate, ethyl acetylacetate, ethyl 2-oxybutyrate or the like, or a combination of the foregoing compounds.

Specific examples of aromatic hydrocarbon compounds include toluene, xylene or the like, or a combination thereof.

Carboxylic acid amide compounds such as N-methylpyrrolidone, N,N-dimethylformamide, N,N-dimethylacetamide or their analogs, or combinations thereof.

The organic solvent (D) may be used alone or in combination.

The organic solvent (D) is preferably propylene glycol methyl ether acetate, cyclohexanone or ethyl 3-ethoxypropionate.

Based on 100 parts by weight of the alkali-soluble resin (A), the amount of the solvent (D) is 500 to 5000 parts by weight, preferably 800 to 4500 parts by weight, and more preferably 1000 to 4000 parts by weight.

The photosensitive resin composition of the present invention may optionally further contain an additive (E) without affecting the efficacy of the present invention. Specific examples of the additive (E) include surfactants, fillers, polymers (other than the alkali-soluble resin (A) mentioned above), adhesion promoters, antioxidants, UV absorbers, or anti-agglomeration agents.

Surfactants help improve the coatability of photosensitive resin compositions. Specific examples of surfactants include cationic surfactants, anionic surfactants, nonionic surfactants, amphoteric surfactants, polysiloxane surfactants, fluorochemical surfactants, or combinations thereof.

Specifically, surfactants include polyoxyethylene alkyl ethers such as polyethoxylauryl ether, polyethoxystearyl ether, and polyethoxyoleyl ether; polyethoxyalkylphenyl ethers such as polyethoxyoctylphenyl ether and polyethoxynonylphenyl ether; polyethylene glycol diesters such as polyethylene glycol dilaurate and polyethylene glycol distearate; sorbitan fatty acid esters; fatty acid-modified polyesters; or tertiary amine-modified polyurethanes. These surfactants can be used alone or in combination.

Specific examples of surfactants include KP products manufactured by Shin-Etsu Chemical Co., Ltd., SF-8427 products manufactured by Dow Corning Toray Co., Ltd., Polyflow products manufactured by Kyoeisha Oil & Fat Chemical Industry Co., Ltd., F-Top products manufactured by Tochem Products Co., Ltd., Megafac products manufactured by Dainippon Ink Chemicals Co., Ltd., Fluorade products manufactured by Sumitomo 3M, Asahi Guard products manufactured by Asahi Glass Co., Ltd., or Surflon products manufactured by Asahi Glass Co., Ltd.

Specific examples of fillers include glass, aluminum, etc.

Specific examples of the polymer include polyvinyl alcohol, polyethylene glycol monoalkyl ether, polyfluoroalkyl acrylate, or a combination of the above polymers.

Specific examples of adhesion promoters include vinyl trimethoxysilane, vinyl triethoxysilane, vinyl tri(2-methoxyethoxy)silane, N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-glycidylpropyltrimethoxysilane, 3-glycidylpropylmethyldiethoxysilane, 3-glycidylpropylmethyldimethoxysilane, silane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-chloropropylmethyldimethoxysilane, 3-chloropropyltrimethoxysilane, 3-methylpropionyloxypropyltrimethoxysilane, 3-butyltrimethoxysilane, 3-glycyrrhetoxypropyltrimethoxysilane, or a combination thereof.

Specific examples of antioxidants include 2,2-thiobis(4-methyl-6-tert-butylphenol), 2,6-di-tert-butylphenol, or a combination thereof.

Specific examples of UV absorbers include 2-(3-tert-butyl-5-methyl-2-hydroxyphenyl)-5-chlorophenylhydrazine, alkoxyphenone, or a combination thereof.

Specific examples of anti-agglomerating agents include sodium polyacrylate and the like.

The present invention further provides a method for forming a spacer or protective film for a liquid crystal display element, characterized in that the method comprises at least the following steps in the following order: (1) applying the aforementioned photosensitive resin composition on a substrate to form a coating film; (2) exposing at least a portion of the coating film; (3) developing the exposed coating film; and (4) heating the developed coating film.

Step (1) is to apply the photosensitive resin composition of the present invention to a substrate to form a coating. When forming the protective film, a pixel layer consisting of red, green, and blue coloring layers is first formed on a transparent substrate, and then the photosensitive resin composition of the present invention is formed on the pixel layer. When forming the spacer, a transparent conductive film is formed on the transparent substrate on which the protective film and pixel layer have been formed, and a coating is formed on the transparent conductive film using the photosensitive resin composition of the present invention.

In a specific embodiment of the present invention, the transparent substrate can be a glass substrate or a resin substrate, and is preferably a glass substrate, such as sodium calcium glass or alkali-free glass. Specific examples of the resin substrate can be polyethylene terephthalate, polybutylene terephthalate, polyether sulfide, polycarbonate, or polyimide.

The transparent conductive substrate may be a NESA film ( ^PPG® , USA) formed of tin oxide (SnO ₂ ) or an ITO film formed of indium oxide-tin oxide (In ₂ O ₃ -SnO ₂ ) on the entire surface of the transparent substrate.

The coating film can be formed by a coating method or a dry film method.

The coating method involves applying a solution of the photosensitive resin composition of the present invention onto the transparent conductive film, preferably pre-heating the coated surface. The solids concentration of the photosensitive resin composition solution used in the coating method is 5 to 50 weight percent, preferably 10 to 40 weight percent, and more preferably 15 to 35 weight percent. The coating method may include, but is not limited to, spray coating, roll coating, spin coating, slot die coating, rod coating, or inkjet coating, with spin coating or slot die coating being preferred.

Secondly, the method of forming the coating film by the dry film method is to stack a photosensitive dry film containing the photosensitive resin composition of the present invention on a base film.

The aforementioned photosensitive dry films can be stacked and, after solvent removal, formed into a photosensitive film. When using the dry film method, the solids concentration of the photosensitive resin composition of the present invention can be 5 to 50 weight percent, preferably 10 to 50 weight percent, more preferably 20 to 50 weight percent, and particularly preferably 30 to 50 weight percent. Specific examples of the base film of the photosensitive dry film can be polyethylene terephthalate (PET), polyethylene, polypropylene, polycarbonate, or polyvinyl chloride. The base film thickness of the photosensitive dry film is preferably 15 to 125 μm, and more preferably 1 to 30 μm.

When the photosensitive dry film is not in use, it can be stacked and covered with a cover film for storage. The cover film of the present invention is preferably releasable so that the photosensitive dry film and the cover film are not separated when the photosensitive dry film is not in use, but can be easily separated when the photosensitive dry film is to be used.

A specific example of a cover film having the aforementioned properties is a silicone release agent coated or printed onto a synthetic resin film, such as a PET film, a polypropylene film, a polyethylene film, a polyvinyl chloride film, or a polyurethane film. The thickness of the cover film is preferably approximately 5 μm to 30 μm. The cover film may also be a two-layer or three-layer laminate.

The specific method of stacking the coating film by the dry film method is to heat-press and bond a transparent photosensitive dry film on a transparent base film.

In the aforementioned method, the coating is preferably produced by a coating method, and secondarily by a dry film method, and preferably the coating is pre-baked. The pre-baking conditions may vary depending on the ingredients and the mixing ratio, but are preferably heated at 70°C to 120°C for 1 minute to 15 minutes.

After the pre-bake treatment, the film thickness is preferably 0.5 μm to 10 μm, and more preferably 1.0 μm to 7.0 μm.

Step (2) is to irradiate at least a portion of the coating with radiation. When irradiating a portion of the coating, a mask having a predetermined pattern may be used to cover the portion.

Specific examples of the radiation used for exposure may be visible light, ultraviolet light, or far infrared light. The wavelength of the radiation is preferably 250 nm to 550 nm, and more preferably 365 nm.

The exposure dose is measured using an illuminometer (OAI model 356, manufactured by Optical Associates) to measure the intensity of radiation with a wavelength of 365 nm. The exposure dose is preferably 100 J/ ^m² to 5,000 J/ ^m² , and more preferably 200 J/ ^m² to 3,000 J/ ^m² .

Step (3) is to develop the coating by irradiating it with radiation to remove unnecessary parts and form a predetermined pattern.

Specific examples of the developer solution for development may include an inorganic base such as sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, or ammonia; a primary aliphatic amine such as ethylamine or n-propylamine; a secondary aliphatic amine such as diethylamine or n-propylamine; a tertiary aliphatic amine such as trimethylamine, diethylaminomethyl, dimethylethylamine, or triethylamine; a tertiary aliphatic cyclic acid such as pyrrole, piperidine, N-methylpiperidine, N-methyl-1,8-diazabicyclo[5.4.0]-7-undecene, or 1,5-diazabicyclo[4.3.0]-5-nonene; a tertiary aromatic amine such as pyridine, methylpyrimidine, lutidine, or quinoline; and a quaternary ammonium salt alkaline compound such as tetramethylammonium hydroxide or an aqueous solution of tetraethylammonium hydroxide. If necessary, a water-soluble organic solvent and/or surfactant, such as methanol or ethanol, may be added to the developer.

The developing method, such as immersion, dipping or showering, is preferably performed at room temperature to 180° C. for about 10 seconds.

The resulting pattern is steam cleaned for 30 to 90 seconds after development and then air-dried with compressed air or nitrogen.

Step (4) is to heat the developed coating film. The obtained coating film with a pattern is heated to 100°C to 250°C using a suitable heater (e.g., a heating plate or an oven) for 30 minutes to 180 minutes (post-baking).

The spacer or protective film having the desired pattern produced above has excellent properties, such as excellent elastic recovery rate and photosensitivity.

The liquid crystal display device of the present invention includes the aforementioned coating (i.e., spacer or protective film). The liquid crystal display device of the present invention preferably forms the spacer with a photosensitive resin composition and forms a protective film on at least one side, and more preferably forms a protective film on both sides of the spacer.

The present invention further provides a liquid crystal display device comprising the aforementioned spacer or protective film. The liquid crystal display device of the present invention can be manufactured by the following two methods:

The first method involves forming the aforementioned photosensitive resin composition on one or both sides of a first (electrode) transparent substrate having a transparent conductive film on at least one side thereof using the aforementioned method. An alignment film having liquid crystal alignment properties is then formed on the transparent conductive film having spacers and/or a protective film.

In the aforementioned substrate, the side formed by the alignment films is called the inner side. This allows the liquid crystals of the various alignment films to be aligned in opposite directions, with a certain gap (the liquid crystal interlayer gap) separating them. Next, the liquid crystal compound is filled into the liquid crystal interlayer gap defined by the substrate surface (alignment films) and the gap, and the filled holes are sealed to form liquid crystal cells. Thus, the inner and outer liquid crystal cells can be bonded to perpendicular polarizers or aligned with the polarization direction of the liquid crystals on a single substrate surface, forming a liquid crystal display device with consistent alignment on both the inner and outer surfaces.

The second method involves applying the photosensitive resin composition of the present invention using the first method to form a protective film or spacer on one or both sides of a first transparent substrate having a transparent conductive film on at least one side. A UV-curable adhesive is then applied along the edges of the substrates. A liquid crystal compound is then dripped onto the substrates using a liquid crystal dispenser, and the substrates are stacked under vacuum. The resulting device is then packaged under UV light and attached to the inner and outer polarizers to produce a liquid crystal display.

Specific examples of the aforementioned liquid crystal compound may be nematic liquid crystals or lamellar liquid crystals, and preferably nematic liquid crystals, such as Shiff base liquid crystals, azoxy liquid crystals, biphenyl liquid crystals, phenylcycloethane liquid crystals, ester liquid crystals, terphenyl liquid crystals, biphenylcyclohexane liquid crystals, pyrimidine liquid crystals, dioxane polycyclooctane liquid crystals, dicyclooctane liquid crystals, pentacyclooctane liquid crystals, chloride liquid crystals, cholesterol carbonate, or cholesterol liquid crystals. The aforementioned liquid crystal compound may also contain a chiral agent, such as strongly induced charge liquid crystals such as p-decyloxybenzylidene-p-amino-2-methylbutylcinnamate (a product of Merck, available under the model numbers C-15 or CB-15).

On the outside of the liquid crystal display element, you can use a polarizing plate or an alignment stretching film such as polyvinyl alcohol, an "H film" that can absorb iodine, or an "H film" placed between a fiber acetate protective film and a polarizing plate.

The present invention is described in detail with the following examples, but it is not intended that the present invention is limited to the contents disclosed in these examples .

To a flask equipped with a stirrer, dropping funnel, condenser, thermometer, and gas inlet tube, add 95 g of propylene glycol monomethyl ether acetate (PGMEA) and 65 g of propylene glycol methyl ether (PGME). Stir while replacing the atmosphere with nitrogen and raise the temperature to 120°C.

Next, 19.0 g of tert-butylperoxy-2-ethylhexanoate (polymerization initiator, manufactured by NOF Corporation, Perbutyl O) was added to a monomer mixture consisting of 0.2 mol of methacrylic acid (MAA), 0.4 mol of dicyclopentyl methacrylate (FA-513M), and 0.4 mol of tricyclo[5.2.1.0 ^2,6 ]dec-8-yl acrylate (FA-511A). The resulting mixture was then added dropwise from a dropping funnel to the aforementioned flask over 2 hours. After the addition was complete, the mixture was stirred at 120°C for 2 hours to allow copolymerization to proceed, forming an addition copolymer. The flask was then replaced with air, and 0.18 mol of glycidyl methacrylate (GMA), 0.6 g of triphenylphosphine (catalyst), and 0.2 g of methyl hydroquinone were added to the above addition copolymer solution and stirred at 110°C for 10 hours for a ring-opening reaction. Subsequently, 0.02 mol of 2-methacryloyloxyethyl isocyanate (MOI) was added to the reaction system, and the esterification reaction was carried out at 70°C for 4 hours. Subsequently, 0.14 mol of succinic anhydride (SA) was added to the reaction system, and the reaction was stirred at 110°C for 3 hours to continue the second esterification reaction. This produced the alkali-soluble resin (A-1-1). Synthesis Examples A-1-2 to A-1-11 and Comparative Synthesis Examples A-1-12 to A-1-13

The alkali-soluble resins of Synthesis Examples A-1-2 to A-1-11 and Comparative Synthesis Examples A-1-12 to A-1-13 were prepared using the same steps as Synthesis Example A-1-1, with the difference being that the monomer components and their amounts were changed (as shown in Table 1). Table 1: In Table 1: code Compound name MAA Methacrylic acid AA Acrylic acid HOMS 2-Methacryloyloxyethyl succinate monoester MA Maleic anhydride FA-513M Dicyclopentanyl methacrylate FA-512M 2-(Tricyclo ^[5.2.1.02,6] dec-3-en-8(9)-oxy)ethyl (meth)acrylate (Dicyclopentenyloxyethyl methacrylate) FA-511A ^{Dicyclopentanyl} Methacrylate NBHE Norbornene (bicyclo[2.2.1]hept-2-ene) MMA Methyl methacrylate BZD benzyl methacrylate GMA Glycidyl methacylate EBA 3,4-epoxy butyl acrylate EC-MAA 3,4-epoxycyclohexylmethyl methacrylate GOEA 2-glycidyloxyethyl acrylate EHMA 6,7-epoxy heptyl methacrylate MOI 2-Methacryloyloxyethyl isocyanate AOI 2-Acryloyloxyethyl isocyanate SA Succinic anhydride THPA Tetrahydrophthalic anhydride MA Maleic acid PGMEA Propylene glycol monomethyl ether acetate EGMEA Ethylene glycol monomethyl ether acetate PGME Propylene glycol methyl ether DGME Diethylene glycol monomethyl ether Synthesis Example A-2-1

To a flask equipped with a stirrer, dropping funnel, condenser, thermometer, and gas inlet tube, add 95 g of propylene glycol monomethyl ether acetate (PGMEA) and 65 g of propylene glycol methyl ether (PGME). Stir while replacing the atmosphere with nitrogen and raise the temperature to 120°C.

Next, 19.0 g of tert-butylperoxy-2-ethylhexanoate (polymerization initiator, manufactured by NOF Corporation, Perbutyl O) was added to a monomer mixture consisting of 0.2 mol of methacrylic acid (MAA), 0.4 mol of dicyclopentyl methacrylate (FA-513M), 0.4 mol of tricyclo[5.2.1.0 ^2,6 ]dec-8-yl acrylate (FA-511A), and 0.18 mol of glycidyl methacrylate (GMA). The resulting mixture was added dropwise from a dropping funnel to the aforementioned flask over 2 hours. After the addition was completed, the mixture was stirred at 120°C for 2 hours to carry out a copolymerization reaction to form an addition copolymer. In this way, an alkali-soluble resin (A-2-1) was obtained. Synthesis Example A-2-2

To a flask equipped with a stirrer, dropping funnel, condenser, thermometer, and gas inlet tube, add 95 g of propylene glycol monomethyl ether acetate (PGMEA) and 65 g of propylene glycol methyl ether (PGME). Stir while replacing the atmosphere with nitrogen and raise the temperature to 120°C.

Next, 19.0 g of tert-butyl peroxy-2-ethylhexanoate (polymerization initiator, manufactured by NOF Corporation, Perbutyl O) was added to a monomer mixture consisting of 0.2 mol of methacrylic acid (MAA), 0.4 mol of dicyclopentyl methacrylate (FA-513M), 0.4 mol of tricyclo[5.2.1.0 ^2,6 ]dec-8-yl acrylate (FA-511A), and 0.02 mol of 2-methacryloyloxyethyl isocyanate (MOI). The resulting mixture was added dropwise from a dropping funnel to the aforementioned flask over 2 hours. After the addition was completed, the mixture was stirred at 120° C. for 2 hours to carry out a copolymerization reaction to form an addition copolymer, thereby obtaining an alkali-soluble resin (A - 2-2).

100 parts by weight of an alkali-soluble resin (A-1-8), 30 parts by weight of ethylene glycol dimethacrylate (B-1), 2.5 parts by weight of a compound represented by formula (I-1) (C-1), 2.5 parts by weight of a compound represented by formula (II-2) (C-4), and 5 parts by weight of 1-[4-(phenylthio)phenyl]-octane-1,2-dione 2-(O-phenylyl oxime) (C-7) were added to 200 parts by weight of propylene glycol monomethyl ether acetate (D-1), and the mixture was stirred uniformly with a shaking stirrer to prepare the photosensitive resin composition of Example 1. Examples 2 to 13 and Comparative Examples 1 to 4

The photosensitive resin compositions of Examples 2 to 13 and Comparative Examples 1 to 4 were prepared using the same steps as Example 1, with the difference being that the types of components and amounts used in the photosensitive resin compositions were changed (as shown in Tables 2-1, 2-2, and 3). Table 2-1: Table 2-2: Table 3: In Table 2-1, Table 2-2 and Table 3: code Compound name B-1 Ethylene glycol dimethacrylate (EGDMA) B-2 Dipentaerythritolhexaacrylate (DPHA) B-3 Trimethylolpropane triacrylate (TMPT) C-1 Compound represented by formula (I-1) C-2 Compound represented by formula (I-5) C-3 Compound represented by formula (I-11) C-4 Compound represented by formula (II-2) C-5 Compound represented by formula (II-6) C-6 Compound represented by formula (II-11) C-7 1-[4-(Phenylthio)phenyl]-octane-1,2-dione 2-(O-phenylyl oxime) (trade name OXE-01, manufactured by Ciba Specialty Chemicals Co., Ltd.) C-8 2-Methyl-1-(4-methylthiophenyl)-2-morpholino-1-propanone (trade name Irgacure 907, manufactured by Ciba Specialty Chemicals Co., Ltd.) D-1 Propylene glycol monomethyl ether acetate (PGMEA) D-2 Ethyl 3-ethoxypropionate (EEP) D-3 Propylene glycol monomethyl ether (PGME) D-4 Acetic acid E-1 3-Glycyrrhetinol propyltrimethoxysilane (KBM-403, manufactured by Shin-Etsu Chemical) E-2 SF-8427 (Dow Corning Toray Silicone Co., Ltd., surfactant) Evaluation method

Elastic Recovery Rate: The resulting gap body (a cylindrical object with a diameter of 25 μm and a height of 3.5 μm) was subjected to a microcompression tester (trade name DUH-201, manufactured by Shimadzu Corporation) using a 50 μm diameter indenter at a loading and unloading rate of 4.413 mN/s. A load of up to 100 mN was applied, held for 5 seconds, and then unloaded. Load-deformation curves and unload-deformation curves were generated. The elastic recovery rate was calculated using the following formula: the difference (L1) between the deformation at a load of 100 mN and the deformation at a load of 5 mN, and the difference (L2) between the deformation at an unload of 100 mN and the deformation at a load of 5 mN. Evaluation was performed based on the following criteria. Elastic Recovery Rate (%) = L2 × 100 / L1 ◎: Elastic Recovery Rate > 75% ○: Elastic Recovery Rate < 65% < 75% △: Elastic Recovery Rate < 55% < 65% ╳: Elastic Recovery Rate < 55%

Photosensitivity: The pre-baked coating prepared above was placed under a designated half-tone mask (50% transmittance) and exposed to UV light at varying exposure doses (exposure machine model AG500-4N; manufactured by M&R Nano Technology) for a weak exposure process. The film thickness (δ) was measured at a random point on the coating. The coating was then immersed in a developer (2.38% tetramethylammonium hydroxide) at 23°C for 2 minutes, and the film thickness (δd) was measured at the same point. Finally, the residual film rate was calculated using the following formula: Residual film rate (%) = [ (δd) / (δ) ] × 100

The exposure level at which the residual film rate reaches 90% or more is called photosensitivity, and is evaluated based on the following criteria: ◎: Exposure level ≤ 70 mJ/cm ² ○: 70 mJ/cm ² < Exposure level ≤ 900 mJ/cm ² △: 90 mJ/cm ² < Exposure level ≤ 110 mJ/cm ² ╳: Exposure level > 110 mJ/cm ² Evaluation results

As shown in Tables 2-1, 2-2, and 3, compared to the resin compositions using the claimed alkali-soluble resin (A-1) (Examples 1 to 13), when the first mixture of the alkali-soluble resin (A-1) does not simultaneously contain the ethylenically unsaturated compound (a-1) and the other copolymerizable ethylenically unsaturated compound (a-2), or when the first mixture is not reacted to form a copolymer, followed by a subsequent reaction with the epoxy-containing compound (a-3) and then with the isocyanate-containing compound (a-4), the resulting resin compositions (Comparative Examples 1 to 4) exhibit poor photosensitivity and elastic recovery.

In addition, when the first mixture for preparing the alkali-soluble resin (A-1) contains a polycarboxylic acid or its anhydride (a-5), the photosensitivity of the resulting resin composition (Examples 5 to 10) can be further improved.

In summary, the resin composition of the present invention, due to its inclusion of a specific alkali-soluble resin (A-1), can improve the problems of poor photosensitivity and elastic recovery rate, and is therefore suitable for use as a spacer or protective film for liquid crystal display devices.

The above embodiments are intended only to illustrate the principles and effects of the present invention and are not intended to limit the present invention. Modifications and variations made by persons skilled in the art to the above embodiments are not inconsistent with the spirit of the present invention. The scope of the present invention is as set forth in the patent application described below.

Claims (9)

A photosensitive resin composition comprises: an alkali-soluble resin (A); a compound having an ethylenically unsaturated group (B); a photoinitiator (C); and an organic solvent (D); wherein the alkali-soluble resin (A) comprises a first alkali-soluble resin (A-1), which is a copolymer formed by reacting a copolymer formed from a first mixture with an epoxy-containing compound (a-3), and then with an isocyanate-containing compound (a-4); the first mixture comprises an ethylenically unsaturated compound containing a carboxylic acid group (a-1), another copolymerizable ethylenically unsaturated compound (a-2), and a polymerization solvent (s); Wherein, based on the total usage of the carboxylic acid group-containing ethylenically unsaturated compound (a-1) and the other copolymerizable ethylenically unsaturated compound (a-2) being 1.0 mol, the usage of the carboxylic acid group-containing ethylenically unsaturated compound (a-1) is 0.2 mol to 0.95 mol, the usage of the other copolymerizable ethylenically unsaturated compound (a-2) is 0.05 mol to 0.8 mol, the usage of the epoxy group-containing compound (a-3) is 0.18 mol to 0.93 mol, and the usage of the isocyanate group-containing compound (a-4) is 0.02 mol to 0.85 mol. The photosensitive resin composition of claim 1, wherein the isocyanate-containing compound (a-4) has a structure represented by the following formula (a4): Formula (a4) In formula (a4), R ₁ is a C ₁ to C ₁₀ alkylene group; and R ₂ is a hydrogen group or a methyl group. The photosensitive resin composition of claim 1, wherein the first alkali-soluble resin (A-1) is further reacted with a polycarboxylic acid or anhydride thereof (a-5). The photosensitive resin composition of claim 3, wherein the total amount of the carboxylic acid group-containing ethylenically unsaturated compound (a-1) and other copolymerizable ethylenically unsaturated compounds (a-2) used is 1.0 mol, and the amount of the polycarboxylic acid or its anhydride (a-5) used is 0.1 mol to 0.93 mol. The photosensitive resin composition of claim 1, wherein the polymerization solvent (s) comprises: an alkyl glycol monoalkyl ether acetate solvent (s-1); and an alkyl glycol monoalkyl ether solvent (s-2). The photosensitive resin composition of claim 5, wherein the total amount of the carboxylic acid group-containing ethylenically unsaturated compound (a-1) and the other copolymerizable ethylenically unsaturated compound (a-2) is 100 parts by weight, the amount of the alkyl glycol monoalkyl ether acetate solvent (s-1) is 60 to 600 parts by weight, and the amount of the alkyl glycol monoalkyl ether acetate solvent (s-2) is 40 to 360 parts by weight. The photosensitive resin composition of claim 1, wherein, based on 100 parts by weight of the alkali-soluble resin (A), the compound having an ethylenically unsaturated group (B) is used in an amount of 30 to 300 parts by weight, the photoinitiator (C) is used in an amount of 10 to 100 parts by weight, and the organic solvent (D) is used in an amount of 120 to 1000 parts by weight. A method for forming a spacer or protective film for a liquid crystal display element, characterized by comprising at least the following steps in the order described below: (1) a step of applying a photosensitive resin composition as described in any one of claims 1 to 7 on a substrate to form a coating film; (2) a step of exposing at least a portion of the coating film; (3) a step of developing the exposed coating film; and (4) a step of heating the developed coating film. A spacer or protective film for a liquid crystal display element is formed by the method of claim 8.