Photosensitive resin composition and insulating film prepared therefrom

Abstract

The present invention relates to a photosensitive resin composition and an insulating film prepared therefrom. The photosensitive resin composition can prepare a colored insulating film without a dye. In addition, the photosensitive resin composition can be cured at a low temperature and can prepare an insulating film that is excellent in all such characteristics as film strength, hardness and resolution.

Description

Technical Field

[0001] The present invention relates to a photosensitive resin composition capable of forming a colored insulating film having excellent film retention, hardness and resolution; and an insulating film prepared therefrom. Background Art

[0002] LCD is a display device that uses the anisotropy of the refractive index of liquid crystal to display information on the screen. It consists of an upper substrate, a lower substrate, and liquid crystals inserted between the substrates. Usually, the lower substrate includes an array of driving elements, the upper substrate includes a color filter, and a spacer with a predetermined thickness is arranged to maintain the gap between the substrates. If necessary, a touch screen panel (TSP) or the like can be connected to the upper substrate.

[0003] The spacing and thickness of the spacers need to be precisely adjusted, and they must be uniformly formed to reduce deformation due to external pressure. Using colored column spacers for inspection is more convenient than transparent spacers.

[0004] In addition, when manufacturing an LCD, an insulating film may be used for the purpose of forming an align key for a more accurate pattern. Typically, TSP is manufactured after an assembly step of an LCD in which a color filter and a thin film transistor (TFT) are attached. In order to minimize the effect on the color filter that has already been manufactured, the insulating film of the TSP must be cured at a low temperature. However, because the problem is that the strength of the insulating film is not sufficient when cured at a low temperature, the TSP is manufactured first, and then the color filter is manufactured. In this case, it would be advantageous for the insulating film of the TSP to have a color in order to position the color filter to the correct position.

[0005] Compositions containing dyes (or pigments) are known as conventional techniques for preparing such colored insulating films (see Korean Patent Publication No. 2015-0008759). However, most techniques using compositions containing dyes have poor dispersibility of the dyes themselves and stability in the compositions, and cannot fully satisfy developability and resolution. DETAILED DESCRIPTION

[0006] Technical issues

[0007] Therefore, the present invention aims to provide a photosensitive resin composition which can be cured at a low temperature and can prepare a colored insulating film without a dye.

[0008] Solution to the problem

[0009] To achieve the above objectives, the present invention provides a photosensitive resin composition comprising (A) a copolymer; (B) a photopolymerizable compound; (C) a photopolymerization initiator; (D) an isocyanate-based compound; and (E) a solvent comprising a cyclic ketone-based compound.

[0010] In order to achieve another object, the present invention provides an insulating film prepared from the photosensitive resin composition.

[0011] Advantageous Effects of the Invention

[0012] The photosensitive resin composition of the present invention can prepare a colored insulating film without a dye. In addition, the photosensitive resin composition of the present invention can be cured at a low temperature and can prepare an insulating film that is excellent in all such characteristics as film strength, hardness and resolution.

[0013] Best Mode for Carrying Out the Invention

[0014] The present invention is not limited to those described below. Instead, it can be modified into various forms as long as the gist of the present invention is not changed.

[0015] Throughout this specification, unless otherwise expressly stated, when a part is referred to as "comprising" an element, it should be understood that other elements may be included rather than excluded. In addition, unless otherwise expressly stated, all numbers and expressions related to the amounts of components, reaction conditions, etc. used herein should be understood to be modified by the term "about".

[0016] The present invention provides a photosensitive resin composition comprising (A) a copolymer; (B) a photopolymerizable compound; (C) a photopolymerization initiator; (D) an isocyanate-based compound; and (E) a solvent comprising a cyclic ketone-based compound.

[0017] The composition may optionally further include (F) a surfactant; and / or (G) a silane coupling agent.

[0018] As used herein, the term “(meth)acryl” refers to “acryl” and / or “methacryl”, and the term “(meth)acrylate” refers to “acrylate” and / or “methacrylate”.

[0019] The weight average molecular weight (g / mol or Da) of each component described below was measured by gel permeation chromatography (GPC, eluent: tetrahydrofuran) (referenced to polystyrene standards).

[0020] (A) Copolymer

[0021] The photosensitive resin composition according to the present invention may include a copolymer (A) as described below as a binder.

[0022] The copolymer may comprise (a1) structural units derived from an ethylenically unsaturated carboxylic acid, an ethylenically unsaturated carboxylic acid anhydride or a combination thereof; (a2) structural units derived from an ethylenically unsaturated compound containing an epoxy group; and (a3) ​​structural units derived from an ethylenically unsaturated compound different from (a1) and (a2).

[0023] (a1) structural units derived from ethylenically unsaturated carboxylic acids, ethylenically unsaturated carboxylic acid anhydrides or combinations thereof

[0024] The structural unit (a1) in the present invention may be derived from an ethylenically unsaturated carboxylic acid, an ethylenically unsaturated carboxylic acid anhydride or a combination thereof.

[0025] Ethylenically unsaturated carboxylic acids, ethylenically unsaturated carboxylic acid anhydrides or combinations thereof are polymerizable unsaturated compounds containing at least one carboxyl group in the molecule. It may be at least one selected from the following: unsaturated monocarboxylic acids such as (meth) acrylic acid, crotonic acid, α-chloroacrylic acid and cinnamic acid; unsaturated dicarboxylic acids and their anhydrides such as maleic acid, maleic anhydride, fumaric acid, itaconic acid, itaconic anhydride, citraconic acid, citraconic anhydride and mesaconic acid; unsaturated polycarboxylic acids having a trivalent or higher valence and their anhydrides; and mono[(meth)acryloyloxyalkyl]esters of divalent or higher valent polycarboxylic acids such as mono[2-(meth)acryloyloxyethyl]succinate, mono[2-(meth)acryloyloxyethyl]phthalate, etc. But it is not limited thereto. Among them, it may preferably be (meth)acrylic acid, particularly from the viewpoint of developability.

[0026] The content of the structural unit (a1) derived from an ethylenically unsaturated carboxylic acid, an ethylenically unsaturated carboxylic anhydride or a combination thereof may be in the range of 5 wt % to 50 wt %, 10 wt % to 40 wt %, or 15 wt % to 35 wt %, based on the total molar number of the structural units constituting the copolymer (A). Within the above range, it is possible to achieve pattern formation of the film while maintaining favorable developability.

[0027] (a2) Structural units derived from ethylenically unsaturated compounds containing epoxy groups

[0028] The structural unit (a2) in the present invention may be derived from an ethylenically unsaturated compound containing an epoxy group.

[0029] Specifically, the structural unit (a2) may include (a2-1) a structural unit derived from an unsaturated monomer containing an alicyclic epoxy group represented by the following formula 1 and (a2-2) a structural unit derived from an unsaturated monomer containing an acyclic epoxy group represented by the following formula 2.

[0030]

[0031] In the above formula, R 2 and R4 are independently hydrogen or C 1-4 Alkyl, and R 1 and R 3 Each is independently C 1-4 More specifically, R 2 and R 4 may each independently be hydrogen or methyl, and R 1 and R 3 Can be C 1-4 Alkylene.

[0032] The unsaturated monomer (a2-1) containing an alicyclic epoxy group may be 3,4-epoxycyclohexylmethyl acrylate or 3,4-epoxycyclohexylmethyl methacrylate. The unsaturated monomer (a2-2) containing an acyclic epoxy group may be glycidyl acrylate or glycidyl methacrylate.

[0033] The total content of the structural units (a2-1) and (a2-2) can be in the range of 10 mol% to 50 mol%, 10 mol% to 45 mol%, 10 mol% to 40 mol%, 10 mol% to 30 mol%, 10 mol% to 20 mol%, 15 mol% to 50 mol%, 15 mol% to 45 mol%, 15 mol% to 40 mol%, 15 mol% to 30 mol%, or 15 mol% to 20 mol%, based on the total moles of the structural units of the copolymer (A). Within the above range, the storage stability of the composition is maintained and the film retention rate is enhanced.

[0034] In addition, the molar ratio of the structural units (a2-1) to (a2-2) is 50 to 99:50 to 1, 50 to 90:50 to 10, 50 to 85:50 to 15, 50 to 80:50 to 20, or 50 to 75:50 to 25. Within the above range, it is possible to achieve excellent stability over time at room temperature, heat resistance and chemical resistance, and enhanced pattern formation.

[0035] (a3) Structural units derived from ethylenically unsaturated compounds other than (a1) and (a2)

[0036] The structural unit (a3) ​​in the present invention may be derived from an ethylenically unsaturated compound different from the structural units (a1) and (a2).

[0037] Specifically, the structural unit (a3) ​​may be at least one selected from the group consisting of: an ethylenically unsaturated compound having an aromatic ring, such as phenyl (meth)acrylate, benzyl (meth)acrylate, 2-phenoxyethyl (meth)acrylate, phenoxydiethylene glycol (meth)acrylate, p-nonylphenoxypolyethylene glycol (meth)acrylate, p-nonylphenoxypolypropylene glycol (meth)acrylate, tribromophenyl (meth)acrylate, styrene, methylstyrene, dimethylstyrene, trimethylstyrene, ethylstyrene, diethylstyrene, triethylstyrene, propylstyrene, butylstyrene, hexylstyrene, heptylstyrene, octylstyrene, fluorophenyl Ethylene, chlorostyrene, bromostyrene, iodostyrene, methoxystyrene, ethoxystyrene, propoxystyrene, p-hydroxy-α-methylstyrene, acetylstyrene, vinyltoluene, divinylbenzene, vinylphenol, o-vinylbenzyl methyl ether, m-vinylbenzyl methyl ether and p-vinylbenzyl methyl ether; unsaturated carboxylic acid esters such as methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, dimethylaminoethyl (meth)acrylate, isobutyl (meth)acrylate, tert-butyl (meth)acrylate, cyclohexyl (meth)acrylate, ethylhexyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, hydroxyethyl (meth)acrylate, (meth)acrylate) 2-Hydroxypropyl (meth)acrylate, 2-Hydroxy-3-chloropropyl (meth)acrylate, 4-Hydroxybutyl (meth)acrylate, Glycerol (meth)acrylate, Methyl α-hydroxymethylacrylate, Ethyl α-hydroxymethylacrylate, Propyl α-hydroxymethylacrylate, Butyl α-hydroxymethylacrylate, 2-Methoxyethyl (meth)acrylate, 3-Methoxybutyl (meth)acrylate, Ethoxydiethylene glycol (meth)acrylate, Methoxytriethylene glycol (meth)acrylate, Methoxytripropylene glycol (meth)acrylate, Poly(ethylene glycol) methyl ether (meth)acrylate, Tetrafluoropropyl (meth)acrylate, 1,1,1,3,3,3-hexadecene (meth)acrylate fluoroisopropyl (meth)acrylate, octafluoropentyl (meth)acrylate, heptadecafluorodecyl (meth)acrylate, isobornyl (meth)acrylate, dicyclopentyl (meth)acrylate, dicyclopentenyl (meth)acrylate, dicyclopentyloxyethyl (meth)acrylate, and dicyclopentenyloxyethyl (meth)acrylate; N-vinyl tertiary amines containing an N-vinyl group, such as N-vinyl pyrrolidone, N-vinyl carbazole, and N-vinyl morpholine; unsaturated ethers, such as vinyl methyl ether and vinyl ethyl ether; and unsaturated imides, such as N-phenylmaleimide, N-(4-chlorophenyl)maleimide, N-(4-hydroxyphenyl)maleimide, and N-cyclohexylmaleimide.

[0038] The total content of structural elements (a3) ​​can be in the range of 5 mol% to 70 mol%, 5 mol% to 65 mol%, 10 mol% to 70 mol%, 10 mol% to 65 mol%, 10 mol% to 60 mol%, 20 mol% to 65 mol%, 20 mol% to 55 mol%, 30 mol% to 65 mol%, 30 mol% to 60 mol%, 30 mol% to 55 mol%, 40 mol% to 65 mol%, 40 mol% to 60 mol%, 40 mol% to 55 mol%, or 40 mol% to 50 mol%, based on the total moles of the structural units of the copolymer (A). Within the above range, it is possible to control the reactivity of the copolymer (A) and increase its solubility, so that the coatability of the photosensitive resin composition is significantly enhanced.

[0039] The copolymer (A) used in the present invention may have a weight average molecular weight of 500 to 50,000 Da, preferably 3,000 to 30,000 Da. If it has a weight average molecular weight within the above range, adhesion to a substrate is excellent, physical and chemical properties are favorable, and viscosity is appropriate.

[0040] Multipolymer (A) for the present invention can be synthesized by copolymerization as known in the art.The content of multipolymer (A) can be in the range of 1 wt % to 80 wt %, 5 wt % to 80 wt %, 5 wt % to 70 wt %, 5 wt % to 60 wt %, 10 wt % to 80 wt %, 10 wt % to 70 wt %, 10 wt % to 60 wt %, 20 wt % to 80 wt %, 20 wt % to 70 wt %, 20 wt % to 60 wt %, 30 wt % to 80 wt %, 30 wt % to 70 wt %, 30 wt % to 60 wt %, 40 wt % to 80 wt %, 40 wt % to 70% wt %, 40 wt % to 60 wt %, 50 wt % to 80 wt %, 50 wt % to 70 wt % or 50 wt % to 60 wt %, based on the gross weight of the photosensitive resin composition not including the surplus solvent. Within the above range, the pattern profile after development is favorable, and such characteristics as film retention rate and chemical resistance are enhanced.

[0041] (B) Photopolymerizable Compound

[0042] The photopolymerizable compound (or monomer) used in the present invention is a compound that is polymerizable under the action of a photopolymerization initiator. It may include a monofunctional or polyfunctional ester compound of acrylic acid or methacrylic acid having at least one ethylenically unsaturated group. From the viewpoint of chemical resistance, it may preferably be a polyfunctional compound having at least two functional groups.

[0043] The polymerizable compound may be at least one selected from the group consisting of ethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, polyethylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, glycerol tri(meth)acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tri(meth)acrylate, and monoesters of succinic acid, pentaerythritol tri(meth)acrylate, and succinic acid. Tetraol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, monoester of dipentaerythritol penta(meth)acrylate and succinic acid, caprolactone-modified dipentaerythritol hexa(meth)acrylate, pentaerythritol triacrylate-hexamethylene diisocyanate (reaction product of pentaerythritol triacrylate and hexamethylene diisocyanate), tripentaerythritol hepta(meth)acrylate, tripentaerythritol octa(meth)acrylate, bisphenol A epoxy acrylate, and ethylene glycol monomethyl ether acrylate, but it is not limited thereto.

[0044] In addition, it may include a polyfunctional urethane acrylate compound obtained by reacting a compound having a linear alkylene group and an alicyclic structure having two or more isocyanate groups with a compound having one or more hydroxyl groups and three, four, or five acryloyloxy and / or methacryloyloxy groups in the molecule.

[0045] Examples of commercially available photopolymerizable compounds may include monofunctional (meth)acrylates such as Aronix M-101, M-111, and M-114 manufactured by Toagosei Co., Ltd., KAYARAD TC-110S and TC-120S manufactured by Nippon Kayaku Co., Ltd., and V-158 and V-2311 manufactured by Osaka Yuki Kagaku Kogyo Co., Ltd.; difunctional (meth)acrylates such as Aronix M-210, M-240, and M-6200 manufactured by Toagosei Co., Ltd., and KAYARAD TC-110S and TC-120S manufactured by Nippon Kayaku Co., Ltd. HDDA, HX-220 and R-604, and V260, V 312 and V 335HP manufactured by Osaka Yuki Kayaku Industry Co., Ltd.; and trifunctional and higher functional (meth)acrylates, such as Aronix M-309, M-400, M-403, M-405, M-450, M-7100, M-8030, M-8060 and TO-1382 manufactured by Toagosei Co., Ltd., KAYARAD TMPTA, DPHA, DPHA-40H, DPCA-20, DPCA-30, DPCA-60 and DPCA-120 manufactured by Nippon Kayaku Co., Ltd., and V-295, V-300, V-360, V-GPT, V-3PA and V-400 manufactured by Osaka Yuki Kayaku Industry Co., Ltd.

[0046] The photopolymerizable compound can be used alone or in combination of two or more thereof. It can be used in the following amounts: 1 to 100 parts by weight, 10 to 80 parts by weight, 20 to 80 parts by weight, 20 to 70 parts by weight, 30 to 80 parts by weight, 30 to 70 parts by weight, 40 to 80 parts by weight, 40 to 70 parts by weight, 50 to 80 parts by weight or 50 to 70 parts by weight, based on 100 parts by weight of the copolymer (A) (based on solid content). Within the above range, it is possible to achieve high sensitivity and excellent pattern developability and film properties.

[0047] (C) Photopolymerization initiator

[0048] The photopolymerization initiator used in the present invention is used to initiate polymerization of monomers that can be cured by visible light, ultraviolet radiation, deep ultraviolet radiation, or the like.

[0049] The photopolymerization initiator may be a free radical initiator. Examples thereof include at least one selected from the group consisting of acetophenone-based, benzophenone-based, benzoin-based, benzoyl-based, xanthone-based, triazine-based, halomethyloxadiazole-based, and rofin dimer-based photopolymerization initiators, but it is not limited thereto.

[0050] Specific examples thereof may include 2,2'-azobis(2,4-dimethylvaleronitrile), 2,2'-azobis(4-methoxy-2,4-dimethylvaleronitrile), benzoyl peroxide, lauroyl peroxide, tert-butyl peroxypivalate, 1,1-bis(tert-butylperoxy)cyclohexane, p-dimethylaminoacetophenone, 2-benzyl-2-(dimethylamino)-1-[4-(4-morpholinyl)phenyl]-1-butanone, 2-hydroxy-2-methyl-1-phenyl-propan-1-one, benzyl dimethyl ketal, benzophenone, benzoin propyl ether, diethylthioxanthone, 2,4-bis(trichloromethyl)-6-p-methoxyphenyl-s-triazine, 2-trichloromethyl-5-phenyl-1-butanone, , 3,4-oxadiazole, 9-phenylacridine, 3-methyl-5-amino-((s-triazine-2-yl)amino)-3-phenylcoumarin, 2-(o-chlorophenyl)-4,5-diphenylimidazolyl dimer, 1-phenyl-1,2-propanedione-2-(o-ethoxycarbonyl)oxime, 1-[4-(phenylthio)phenyl]-octane-1,2-dione-2-(o-benzoyloxime), o-benzoyl-4'-(benzothio)benzoylhexylketone oxime, 2,4,6-trimethylphenylcarbonyl-diphenylphosphonyl oxide, hexafluorophosphino-trialkylphenylsulfonium salt, 2-mercaptobenzimidazole, 2,2'-benzothiazolyl disulfide, and mixtures thereof, but it is not limited thereto. In addition, oxime-based compounds disclosed in KR2004-0007700, KR 2005-0084149, KR 2008-0083650, KR 2008-0080208, KR 2007-0044062, KR 2007-0091110, KR 2007-0044753, KR 2009-0009991, KR 2009-0093933, KR 2010-0097658, KR 2011-0059525, WO 10102502, and WO 10133077 may be used.

[0051] The photopolymerization initiator can be used in the following amounts: 0.1 to 20 parts by weight, 0.1 to 15 parts by weight, 1 to 20 parts by weight, 1 to 15 parts by weight, 1 to 10 parts by weight, 1 to 8 parts by weight, 1 to 6 parts by weight, 1 to 5 parts by weight, 2 to 10 parts by weight, 2 to 8 parts by weight, 2 to 6 parts by weight, or 2 to 5 parts by weight, based on 100 parts by weight of the copolymer (A) (based on solid content). Within the above range, it is possible to achieve high sensitivity and excellent pattern developability and film properties.

[0052] (D) Isocyanate-based compounds

[0053] The isocyanate-based compound used in the present invention acts as an adhesion aid. The -NCO group of the isocyanate-based compound has a high reactivity that is easy to react with compounds having active hydrogen (such as hydroxyl, amine, carboxyl, epoxy), water, acid, etc. The cross-linking reaction through such a reaction can further enhance the adhesion between the insulating film and the substrate.

[0054] At the same time, it reacts with other components in the photosensitive resin composition, such as the copolymer (A) and the solvent (E), to form a three-dimensional polymer compound having a color, so that the insulating film exhibits the color.

[0055] The isocyanate-based compound can be at least one selected from the group consisting of 3-isocyanatopropyltrimethoxysilane, 3-isocyanatopropyltriethoxysilane, allyl isocyanate, (trimethylsilyl)isocyanate, (R)-(-)-3-methyl-2-butyl isocyanate, (R)-(+)-1-phenylpropyl isocyanate, (R)-(-)-2-heptyl isocyanate, hexyl isocyanate, butyl isocyanate, isopropyl isocyanate, cyclohexyl isocyanate, propyl isocyanate, octadecyl isocyanate, phenyl isocyanate, 2-isocyanatoethyl methacrylate, 2-isocyanatoethyl acrylate, 1,1-(bisacryloyloxyethyl)isocyanate, ethyl isocyanurate, and 2-isocyanatoethyl acrylate.

[0056] In addition, it may further include a polyfunctional isocyanate-based compound polymer.

[0057] For example, KBE-9007N from Shinetsu Co., Ltd. may be used as the isocyanate-based compound, and X-12-1159L from Shinetsu Co., Ltd. may be further used.

[0058] The isocyanate-based compound can be used in an amount of 0.01 to 5 parts by weight, 0.01 to 3 parts by weight, 0.1 to 5 parts by weight, 0.2 to 5 parts by weight, 0.1 to 3 parts by weight, or 0.2 to 3 parts by weight, based on 100 parts by weight of the copolymer (A) (based on solid content). Within the above range, it is possible to obtain an insulating film having excellent adhesion to a substrate and having an (opaque) color.

[0059] (E) Solvent

[0060] The photosensitive resin composition of the present invention may be prepared as a liquid composition in which the above components are mixed with a solvent. In this case, the solvent may contain a cyclic ketone-based compound.

[0061] Specifically, the cyclic ketone-based compound may be at least one selected from the group consisting of cyclohexanone, cyclopentanone, and cyclobutanone. It may preferably be cyclopentanone.

[0062] The cyclic ketone-based compound may have a boiling point of 70°C to 160°C, 90°C to 150°C, or 120°C to 140°C.

[0063] Cyclic ketone-based compounds are used to impart color to the insulating film.

[0064] Specifically, a cyclic ketone-based compound can form a compound having a color through an aldol reaction in the presence of an acid catalyst. Cyclopentanone, for example, undergoes enolization, aldol addition, and dehydration to form yellow 2-cyclopentylidenecyclopentane-1-one.

[0065] In addition, other solvents may be further used in the present invention as long as they are compatible with the components of the photosensitive resin composition as described above and they do not impair the effects of the present invention.

[0066] Examples of such solvents include ethylene glycol monoalkyl ether acetates such as ethylene glycol monomethyl ether acetate and ethylene glycol monoethyl ether acetate; propylene glycol monoalkyl ethers such as propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether and propylene glycol monobutyl ether; propylene glycol dialkyl ethers such as propylene glycol dimethyl ether, propylene glycol diethyl ether, propylene glycol dipropyl ether and propylene glycol dibutyl ether; dipropylene glycol dialkyl ethers such as dipropylene glycol dimethyl ether; propylene glycol monoalkyl ether acetates such as propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol monopropyl ether acetate and propylene glycol monobutyl ether acetate; cellosolves such as ethyl cellosolve and butyl cellosolve; carbitols such as butyl carbitol; lactic acid esters such as methyl lactate, ethyl lactate, n-propyl lactate Esters and isopropyl lactate; aliphatic carboxylic acid esters, ethyl acetate, n-propyl acetate, isopropyl acetate, n-butyl acetate, isobutyl acetate, n-pentyl acetate, isopentyl acetate, isopropyl propionate, n-butyl propionate and isobutyl propionate; esters such as methyl 3-methoxypropionate, ethyl 3-methoxypropionate, methyl 3-ethoxypropionate, ethyl 3-ethoxypropionate, methyl pyruvate and ethyl pyruvate; aromatic hydrocarbons such as toluene and xylene; ketones such as 2-heptanone, 3-heptanone and 4-heptanone; amides such as N-dimethylformamide, N-methylacetamide, N,N-dimethylacetamide and N-methylpyrrolidone; lactones such as γ-butyrolactone; and mixtures thereof, but they are not limited thereto. The solvent may be used alone or in combination of two or more.

[0067] In the photosensitive resin composition according to the present invention, the content of the solvent is not particularly limited from the viewpoint of coatability and stability of the photosensitive resin composition thus prepared, but the solvent may be used so that the solid content is 5 wt % to 80 wt %, 5 wt % to 70 wt %, 5 wt % to 60 wt %, 10 wt % to 70 wt %, 10 wt % to 60 wt %, 10 wt % to 55 wt %, 10 wt % to 50 wt %, 10 wt % to 45 wt %, 10 wt % to 40 wt %, 10 wt % to 30 wt %, 20 wt % to 60 wt %, 20 wt % to 55 wt %, 20 wt % to 50 wt %, 20 wt % to 45 wt %, 20 wt % to 40 wt %, or 20 wt % to 30 wt %, based on the total weight of the composition.

[0068] In addition, the solvent may contain the cyclic ketone-based compound in an amount of 1 wt % to 90 wt %, 1 wt % to 70 wt %, 1 wt % to 50 wt %, 1 wt % to 30 wt %, 5 wt % to 100 wt %, 5 wt % to 50 wt %, 5 wt % to 40 wt %, 5 wt % to 30 wt %, 5 wt % to 20 wt %, 7 wt % to 90 wt %, 7 wt % to 50 wt %, 10 wt % to 90 wt %, or 10 wt % to 50 wt %, based on the total weight of the solvent.

[0069] In the above range, compatibility with other components in the photosensitive resin composition is favorable, and storage stability even at room temperature or low temperature is excellent. In addition, when the insulating film is formed (coated), the solvent can be retained in an appropriate amount at the pre-baking temperature so that it can help to form or level the coating film. In addition, it can be fully evaporated at a temperature of 70°C to 150°C to form a coating film when cured at low temperature.

[0070] In addition, the photosensitive resin composition of the present invention may further include other components to improve its characteristics. For example, the other components may include a surfactant (F) and / or a silane coupling agent (G).

[0071] (F) Surfactant

[0072] If necessary, the photosensitive resin composition of the present invention may further include a surfactant in order to enhance coatability and to prevent generation of defects.

[0073] The type of surfactant is not particularly limited. Preferably, it may include fluorine-based surfactants, silicone-based surfactants, nonionic surfactants, etc. Preferably, from the viewpoint of dispersibility, BYK-307 from BYK can be used among the above.

[0074] Examples of the surfactant may include fluorine-based and silicone-based surfactants, such as BM-1000 and BM-1100 supplied by BM CHEMIE Co., Ltd., Megapack F142 D, F172, F173, F183, F-470, F-471, F-475, F-482 and F-489 supplied by Dai Nippon Ink Chemical Kogyo Co., Ltd., Florad FC-135, FC-170C, FC-430 and FC-431 supplied by Sumitomo 3M Ltd., Sufron supplied by Asahi Glass Co., Ltd. S-112, S-113, S-131, S-141, S-145, S-382, SC-101, SC-102, SC-103, SC-104, SC-105 and SC-106, Eftop EF301, 303 and 352 supplied by Shinakida Kasei Co., Ltd., SH-28PA, SH-190, SH-193, SZ-6032, SF-8428, DC-57 and DC-190 supplied by Toray Silicone Co., Ltd., Dow Corning Toray Silicone Co., Ltd.), TSF-4440, TSF-4300, TSF-4445, TSF-4446, TSF-4460 and TSF-4452 supplied by GE Toshiba Silicones Co., Ltd., and BYK Corporation); nonionic surfactants such as polyoxyethylene alkyl ethers such as polyoxyethylene lauryl ether, polyoxyethylene stearyl ether and polyoxyethylene oleyl ether; polyoxyethylene aryl ethers such as polyoxyethylene octylphenyl ether and polyoxyethylene nonylphenyl ether; and polyoxyethylene dialkyl esters such as polyoxyethylene dilaurate and polyoxyethylene distearate; and organosilicone polymer KP341 (supplied by Shin-Etsu Chemical Co., Ltd.)), (meth)acrylate-based copolymers Polyflow No. 57 and 95 (manufactured by Kyoei Yuji Chemical Co., Ltd.), etc. They may be used alone or in combination of two or more thereof. .

[0075] The surfactant can be used in the following amounts: 0.0001 to 5 parts by weight, 0.0001 to 3 parts by weight, 0.001 to 5 parts by weight, 0.001 to 3 parts by weight, 0.01 to 5 parts by weight, 0.01 to 3 parts by weight, 0.1 to 5 parts by weight, or 0.1 to 3 parts by weight, based on 100 parts by weight of the copolymer (A) (based on solid content). Within the above range, the coating of the composition is smoothly carried out.

[0076] (G) Silane coupling agent

[0077] In order to enhance adhesion to a substrate, the photosensitive resin composition of the present invention may further include a silane coupling agent having at least one reactive group selected from the group consisting of a carboxyl group, a (meth)acryloyl group, an amino group, a mercapto group, a vinyl group, and an epoxy group.

[0078] The type of silane coupling agent is not particularly limited. It can be at least one selected from the group consisting of trimethoxysilylbenzoic acid, γ-methacryloxypropyltrimethoxysilane, vinyltriacetoxysilane, vinyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane and β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane. Preferred is γ-glycidoxypropyltrimethoxysilane or γ-glycidoxypropyltriethoxysilane having an epoxy group, which can improve the film retention rate and has excellent adhesion to the substrate.

[0079] The silane coupling agent can be used in an amount of 0.0001 to 5 parts by weight, 0.0001 to 3 parts by weight, 0.001 to 5 parts by weight, 0.001 to 3 parts by weight, 0.01 to 5 parts by weight, 0.01 to 3 parts by weight, 0.01 to 1 part by weight, 0.1 to 5 parts by weight, or 0.1 to 3 parts by weight, based on 100 parts by weight of the copolymer (A) (based on solid content). Within the above range, adhesion to the substrate is favorable.

[0080] In addition, the photosensitive resin composition of the present invention may further include other additives such as antioxidants and stabilizers as long as the physical properties of the photosensitive resin composition are not adversely affected.

[0081] The photosensitive resin composition of the present invention as described above can be cured at a relatively low temperature. Specifically, the curing temperature can be 70 to 150°C, 100 to 150°C, 100 to 140°C, or 110 to 130°C.

[0082] The present invention provides an insulating film (or cured film) formed from a photosensitive resin composition.

[0083] The insulating film can be prepared by methods known in the art. For example, the photosensitive resin composition is applied to the substrate by spin coating, and is subjected to pre-baking for 60 seconds to 130 seconds at a temperature of 60°C to 130°C to remove the solvent. It is then exposed using a photomask with a desired pattern and subjected to development using a developer (e.g., tetramethylammonium hydroxide (TMAH) solution) to form a pattern on the coating. Thereafter, if necessary, the patterned coating is subjected to post-baking for 10 minutes to 5 hours at a temperature of 70°C to 150°C to prepare the desired insulating film.

[0084] It can be used in the wavelength range of 200nm to 450nm with a wavelength of 365nm and a power of 10mJ / cm 2 Up to 100mJ / cm 2 According to the method of the present invention, it is possible to easily form a desired pattern from the viewpoint of the method.

[0085] The photosensitive resin composition can be applied to the substrate in a desired thickness (e.g., 2 μm to 25 μm) by spin coating, slit coating, roller coating, screen printing, applicator, etc. In addition, a low-pressure mercury lamp, a high-pressure mercury lamp, an ultra-high-pressure mercury lamp, a metal halide lamp, an argon laser, etc. can be used as a light source for exposure (irradiation). If necessary, X-rays, electron rays, etc. can also be used.

[0086] The photosensitive resin composition of the present invention can form an opaque (colored) insulating film that is excellent in heat resistance, solvent resistance, acid resistance, alkali resistance, film retention rate, hardness, and resolution.

[0087] For example, the insulating film may have a transmittance of 80% or less, 78% or less, or 70% or less at a wavelength of 400 nm (see Evaluation Example 3).

[0088] Therefore, when the insulating film of the present invention thus formed is subjected to heat treatment or immersed in a solvent, acid, alkali, etc. or brought into contact with a solvent, acid, alkali, etc., the insulating film has excellent physical properties (such as resolution and hardness, no surface roughness). Therefore, it can be effectively used as a planarization film for a thin film transistor (TFT) substrate for a liquid crystal display or an organic EL display; a partition of an organic EL display; an interlayer dielectric of a semiconductor device; a core or cladding material of an optical waveguide, etc.

[0089] Embodiments of the present invention

[0090] Hereinafter, the present invention will be described in more detail with reference to the following examples. However, these examples are provided to illustrate the present invention, and the scope of the present invention is not limited thereto.

[0091] In the following preparation examples, the weight average molecular weight was determined by gel permeation chromatography (GPC, eluent: tetrahydrofuran) with reference to a polystyrene standard.

[0092] Examples

[0093] Preparation Example 1: Preparation of Copolymer (A)

[0094] Into a 500-ml round-bottom flask equipped with a reflux condenser and a stirrer, 40 g of a monomer mixture consisting of 50 mol % of styrene, 22 mol % of methacrylic acid, 10 mol % of glycidyl methacrylate and 18 mol % of 3,4-epoxycyclohexylmethyl methacrylate, together with 120 g of methyl 3-methoxypropionate (MMP) as a solvent and 2 g of 2,2'-azobis(2,4-dimethylvaleronitrile) as a free radical polymerization initiator were charged. Thereafter, the temperature was raised to 70°C while stirring for 8 hours to obtain a copolymer (A) solution having a solid content of 33 wt %. The copolymer (A) thus prepared had a weight average molecular weight of 7,000 Da.

[0095] Example and Comparative Example: Preparation of Photosensitive Resin Composition

[0096] The components used in the following Examples and Comparative Examples are as follows.

[0097] [Table 1]

[0098]

[0099] Example 1

[0100] 100 parts by weight of the copolymer (A) prepared in Preparation Example 1, 66.7 parts by weight of 6-functional dipentaerythritol hexaacrylate as a photopolymerizable compound, 5.2 parts by weight of OXE-02 (C) as a photopolymerization initiator, 0.9 parts by weight of 3-isocyanatepropyltriethoxysilane (D) as an isocyanate-based compound, and 1.7 parts by weight of a surfactant (F) were mixed. Here, the corresponding contents are those based on the solid content excluding the solvent. Thereafter, cyclopentanone (E-1) was added to the mixture so that the solid content of the mixture was 21% by weight. The resulting mixture was mixed using a vibrator for 2 hours to prepare a liquid photosensitive resin composition.

[0101] Examples 2 and 3 and Comparative Examples 1 and 2

[0102] Photosensitive resin compositions were each prepared in the same manner as in Example 1, except that the kinds and / or contents of the corresponding components were changed as shown in Table 2 below.

[0103] [Table 2]

[0104]

[0105] [Evaluation Example]

[0106] An insulating film was prepared from each of the photosensitive resin compositions obtained in Examples 1 to 3 and Comparative Examples 1 and 2. The film retention rate, pencil hardness, transmittance, and resolution of the insulating film were evaluated, and the results are shown in Table 3 below.

[0107] [Preparation of insulating film]

[0108] The photosensitive resin compositions obtained in the examples and comparative examples were each coated on a glass substrate using a spin coater and pre-baked at 100°C for 60 seconds to form a coated film. A mask was placed on the coated film so formed that an area of ​​5 cm by 5 cm of the coated film was 100% exposed and a gap of 25 μm with the substrate was maintained. Thereafter, an aligner (model name: MA6) emitting light having a wavelength of 200 nm to 450 nm was used at 30 mJ / cm based on a wavelength of 365 nm. 2 The film was exposed to light for a certain period of time with an exposure dose of 1.50 wt %. The exposed film was developed with an aqueous developer of 2.38 wt % tetramethylammonium hydroxide (TMAH) at 23° C. until the unexposed portion was completely washed off. The exposed film on which a pattern was formed was heated (post-baked) in an oven at 130° C. for 1 hour to obtain an insulating film having a thickness of 2.5 (±0.2) μm.

[0109] Evaluation Example 1: Membrane Retention Rate

[0110] The initial thickness after prebaking was measured according to the method for preparing an insulating film. After the method for preparing an insulating film, it was developed with an aqueous solution of TMAH diluted to 2.38 wt % at 23°C. The thickness after curing at 130°C for 1 hour was measured. The film retention rate was obtained by calculating the ratio of the final insulating film thickness to the film thickness after prebaking in percentage.

[0111] Evaluation Example 2: Pencil Hardness

[0112] An insulating film having a total thickness of 2.5 (± 0.2) μm after final curing was prepared according to the method for preparing an insulating film. A weight of 500 g was applied at a constant speed and angle (45°) in the same direction using a pencil hardness tester to observe the degree of damage to the insulating film with Mitsubishi UNI pencils of 6B to 9H.

[0113] Evaluation Example 3: Transmittance (UV-vis)

[0114] A preliminary insulating film having a thickness of 2.5 μm was formed on a glass substrate according to a method of preparing an insulating film. The transmittance was measured by the following method.

[0115] The transmittance was measured by scanning the wavelength region from 200 nm to 800 nm using an ultraviolet / visible light meter (Varian UV spectrometer) and measuring the transmittance at a wavelength of 400 nm. The lower the transmittance at a wavelength of 400 nm, the better.

[0116] Evaluation Example 4: Resolution (Photolithography performance)

[0117] The compositions prepared in the examples and comparative examples were each uniformly coated on a glass substrate by spin coating, and then dried on a hot plate maintained at 100° C. for 1 minute to form a substrate. A negative mask having an opening pattern with a line width of 30 μm was placed on the substrate with the dried film formed. Then, an aligner (model name: MA6) was used to irradiate the substrate at 30 mJ / cm 2 The substrate was exposed to an exposure dose of 1.50 μm and developed at 23° C. using an aqueous solution of TMAH diluted to 2.38 wt % until the unexposed portion was completely washed off. Thereafter, the exposed film having a pattern formed thereon was post-baked in an oven at 130° C. for 1 hour to obtain an insulating film having a thickness of 2.5 (± 0.2) μm. For the substrate having an insulating film formed thereon, the line width at the bottom of the pattern was measured with a non-contact thickness meter (SIS-2000, SNU), and the resolution was evaluated according to the following criteria.

[0118] ○: The bottom line opens with a width of 20 μm or more.

[0119] ×: The bottom line opens with a width of less than 20 μm.

[0120] [Table 3]

[0121]

[0122] As can be seen from Table 3, the insulating films obtained from the compositions of Examples falling within the scope of the present invention generally have excellent film retention, pencil hardness, and resolution, and a desired level of transmittance. In contrast, the insulating films obtained from the compositions of Comparative Examples 1 and 2 falling outside the scope of the present invention have poor film retention and resolution compared to the insulating films prepared in the Examples, and do not achieve a desired level of transmittance.

Claims

1. A photosensitive resin composition comprising: (A) copolymers; (B) a photopolymerizable compound; (C) a photopolymerization initiator; (D) isocyanate-based compounds; and (E) a solvent comprising a cyclic ketone-based compound, The isocyanate-based compound is at least one selected from the group consisting of 3-isocyanatopropyltrimethoxysilane, 3-isocyanatopropyltriethoxysilane, allyl isocyanate, (trimethylsilyl)isocyanate, (R)-(-)-3-methyl-2-butylisocyanate, (R)-(+)-1-phenylpropylisocyanate, (R)-(-)-2-heptylisocyanate, hexylisocyanate, butylisocyanate, isopropylisocyanate, cyclohexylisocyanate, propylisocyanate, octadecylisocyanate, phenylisocyanate, 2-isocyanatoethylmethacrylate, 2-isocyanatoethylacrylate, 1,1-(bisacryloyloxyethyl)isocyanate, ethylisocyanurate, and 2-isocyanatoethylacrylate, The cyclic ketone-based compound is at least one selected from the group consisting of cyclohexanone, cyclopentanone, and cyclobutanone.

2. The photosensitive resin composition according to claim 1, wherein The copolymer (A) comprises (a1) structural units derived from ethylenically unsaturated carboxylic acids, ethylenically unsaturated carboxylic acid anhydrides or combinations thereof; (a2) a structural unit derived from an ethylenically unsaturated compound containing an epoxy group; and (a3) ​​a structural unit derived from an ethylenically unsaturated compound different from (a1) and (a2).

3. The photosensitive resin composition according to claim 2, wherein The structural unit (a2) comprises (a2-1) a structural unit derived from an unsaturated monomer containing an alicyclic epoxy group represented by the following formula 1 and (a2-2) a structural unit derived from an unsaturated monomer containing an acyclic epoxy group represented by the following formula 2: [Formula 1] [Formula 2] In the above formula, R 2 and R 4 are independently hydrogen or C 1-4 Alkyl, and R 1 and R 3 Each is independently C 1-4 Alkylene.

4. The photosensitive resin composition according to claim 3, wherein The total content of the structural units (a2-1) and (a2-2) ranges from 10 mol% to 50 mol% based on the total moles of the structural units of the copolymer (A).

5. The photosensitive resin composition according to claim 3, wherein The molar ratio of the structural units (a2-1) to (a2-2) is 50 to 99:50 to 1.

6. The photosensitive resin composition according to claim 1, wherein The cyclic ketone-based compound has a boiling point of 70°C to 160°C.

7. The photosensitive resin composition according to claim 1, wherein The solvent (E) includes the cyclic ketone-based compound in an amount of 5 wt % to 100 wt % based on the total weight of the solvent (E). 8 . The photosensitive resin composition of claim 1 , having a curing temperature of 70° C. to 150° C. 9 . An insulating film prepared from the photosensitive resin composition according to claim 1 . 10 . The insulating film according to claim 9 , which has a transmittance of 80% or less at a wavelength of up to 400 nm.

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