Photosensitive resin composition for color filter, photosensitive resin film, photosensitive dry film, pattern forming method, display device, and micro LED display

Abstract

The present invention is a photosensitive resin composition for a color filter, the photosensitive resin composition being characterized by containing (A) an acrylic resin having a (meth)acryloyl group in a side chain, (B) a dye having an absorption maximum wavelength of 430-490 nm, (C) an oxime-based photoradical generator, (D) a polyfunctional secondary thiol compound, (E) a surfactant, and (F) a solvent. Thus, provided is a photosensitive resin composition for a color filter, the photosensitive resin composition providing a cured product capable of absorbing blue light that has passed through a quantum dot-containing photoresist cured film and selectively extracting only red or green light.

Description

Photosensitive resin composition for color filters, photosensitive resin film, photosensitive dry film, pattern forming method, display device, and micro LED display

[0001] The present invention relates to a photosensitive resin composition for color filters, a photosensitive resin film, a photosensitive dry film, a pattern forming method, a display device, and a micro LED display.

[0002] Various methods have been proposed for forming a display including red, green, and blue sub-pixels. One of these methods is converting light from an LED array from a shorter wavelength of blue light to longer wavelengths of red and green light through a color conversion structure. Quantum dots are used as the material responsible for this color conversion.

[0003] In recent years, such LED arrays have been miniaturized to micro sizes, and micro LED displays using such arrays have attracted attention. As a method for forming a color conversion structure on an LED array, a lithography process using a photosensitive material is known (Patent Document 1). However, when securing the transmittance of the exposure wavelength during the lithography process for pattern formation, generally the absorbance of quantum dots at the exposure wavelength in the lithography process is higher than the absorbance thereof at the wavelength of blue LED light. Therefore, when blue LED light is applied to the cured film from below, blue light that is not color-converted by the quantum dots and transmits through the cured film emerges to the surface, resulting in a problem that the display lacks sharpness.

[0004] Japanese Unexamined Patent Publication No. 2021-089347

[0005] In the prior art, the three primary colors of light are formed by three types of sub-pixels: a sub-pixel in which a red-emitting quantum dot-containing photoresist cured film is laminated on a blue LED, a sub-pixel in which a green-emitting quantum dot-containing photoresist cured film is laminated on a blue LED, and a sub-pixel formed of a blue LED on which no cured film is laminated, and these three sub-pixels constitute one pixel to express full-color images. However, if the quantum dot-containing photoresist cured film transmits blue light, it becomes difficult to achieve satisfactory full-color expression.

[0006] To solve this problem, it is necessary to develop a material that can selectively form a highly reliable layer that absorbs blue light only on top of a photoresist cured film containing red or green-emitting quantum dots (because if the quantum dot-containing photoresist cured film is also layered on subpixels consisting of blue LEDs where the quantum dot-containing photoresist cured film is not layered, it will become impossible to extract blue light).

[0007] The present invention was made to solve the above problems, and aims to provide a photosensitive resin composition for color filters that provides a cured product capable of absorbing blue light that has passed through a quantum dot-containing photoresist cured film, and selectively extracting only red or green light.

[0008] To solve the above problems, the present invention provides a photosensitive resin composition for color filters, characterized by comprising: (A) an acrylic resin having (meth)acryloyl groups in its side chains; (B) a dye having an absorption maximum wavelength of 430 to 490 nm; (C) a carbazole-based oxime ester radical generator; (D) a polyfunctional secondary thiol compound; (E) a surfactant; and (F) a solvent.

[0009] Such a photosensitive resin composition for color filters can form a photosensitive coating or photosensitive dry film that absorbs blue light transmitted through a quantum dot-containing photoresist cured film, and selectively and efficiently extracts only red or green light. Furthermore, a pattern forming method using the photosensitive resin composition or photosensitive dry film for color filters of the present invention makes it possible to easily form fine patterns with excellent verticality.

[0010] Furthermore, in the present invention, it is preferable that the (D) component is one or more selected from those represented by the following formulas (D1), (D2), (D3), and (D4).

[0011] Such a photosensitive resin composition for color filters is preferable from the viewpoint of availability.

[0012] Furthermore, it is preferable that component (A) of the photosensitive resin composition for color filters of the present invention has a weight-average molecular weight Mw of 10,000 to 50,000 and a double bond equivalent of 200 to 650 g / mol.

[0013] Such a photosensitive resin composition for color filters is said to be less prone to film reduction in the exposed areas during development, and to have good solubility in the unexposed areas.

[0014] Furthermore, in the present invention, it is preferable that component (B) is included in the non-volatile components of the color filter photosensitive resin composition in an amount of 0.5 to 15% by mass.

[0015] If the content of component (B) included in the present invention is within the above range, fine patterns can be formed while maintaining good blue LED light absorption characteristics.

[0016] Furthermore, in the present invention, it is preferable that component (C) is a carbazole-based oxime ester compound having a maximum absorption wavelength of 350 nm or more, and that it is included in the non-volatile components of the color filter photosensitive resin composition in an amount of 0.1 to 1.5% by mass.

[0017] Such a photosensitive resin composition for color filters can improve sensitivity during lithography and enable the formation of fine patterns while maintaining good luminescence characteristics.

[0018] Furthermore, in the present invention, it is preferable that component (D) is included in the non-volatile components of the color filter photosensitive resin composition in an amount of 2 to 50% by mass.

[0019] If component (D) included in the present invention is within the above range, curing can be promoted to form a pattern with good rectangularity, and a cured film with high reliability and chemical resistance can be formed.

[0020] Furthermore, the present invention may also include (G) a polyfunctional (meth)acrylate having a double bond equivalent of 300 g / mol or less.

[0021] The photosensitive resin composition for color filters of the present invention contains component (G) within the above range, thereby increasing the crosslinking density and enabling the formation of a pattern with a good shape after development.

[0022] Preferably, the photosensitive resin composition for the color filter absorbs blue LED light transmitted through a photoresist cured film containing quantum dots capable of emitting red or green fluorescence.

[0023] With such a photosensitive resin composition for color filters, a cured film can be obtained that absorbs the blue light that has been transmitted through the quantum dot-containing photoresist cured film, and selectively extracts only red or green light.

[0024] Furthermore, the present invention provides a photosensitive resin film which is a dried body of the photosensitive resin composition for color filters described above.

[0025] This pattern formation method using a photosensitive resin coating makes it possible to easily form fine and highly perpendicular patterns.

[0026] Furthermore, the present invention provides a photosensitive dry film comprising a support film and a photosensitive resin coating described above on the support film.

[0027] With such a photosensitive dry film, when it is applied to a substrate with uneven surfaces, the photosensitive resin coating follows the contours of the surface, achieving high flatness.

[0028] Furthermore, the present invention provides a pattern forming method comprising: (i) applying the above-mentioned photosensitive resin composition for color filters onto a substrate to form a photosensitive resin film on the substrate; (ii) exposing the photosensitive resin film to light; and (iii) developing the exposed photosensitive resin film with a developer solution to dissolve and remove the unexposed areas and form a pattern.

[0029] This pattern formation method makes it possible to easily form fine and highly perpendicular patterns.

[0030] Furthermore, the present invention provides a pattern forming method comprising: (i') a step of attaching the above-mentioned photosensitive dry film to a substrate to form the photosensitive resin film on the substrate; (ii) a step of exposing the photosensitive resin film to light; and (iii) a step of developing the exposed photosensitive resin film with a developer solution to dissolve and remove the unexposed areas and form a pattern.

[0031] This pattern formation method using a photosensitive dry film makes it possible to easily form fine and highly perpendicular patterns.

[0032] Furthermore, in the pattern formation method using the above-mentioned photosensitive resin composition for color filters, it is preferable to use a substrate having a pattern formed with a quantum dot-containing photoresist capable of emitting red or green fluorescence.

[0033] With this pattern formation method, it is possible to selectively form fine patterns on the pattern formed with the quantum dot-containing photoresist.

[0034] Furthermore, in the pattern formation method using the above-described photosensitive dry film, it is preferable to use a substrate having a pattern formed with a quantum dot-containing photoresist capable of emitting red or green fluorescence.

[0035] With this pattern formation method, it is possible to selectively form fine patterns on the pattern formed with the quantum dot-containing photoresist.

[0036] Furthermore, the present invention provides a display device in which the above-described photosensitive resin composition for color filters is used to create a patterned cured film that absorbs blue LED light that was not color-converted by quantum dots, and extracts only the light that has been converted to red or green from each subpixel.

[0037] The cured film obtained from the photosensitive resin composition for color filters of the present invention can be given high constant temperature and humidity test resistance and chemical resistance without affecting chromaticity, and also maintains high adhesion even after chemical resistance testing, making it suitable for use in display devices.

[0038] Further, in the present invention, the photosensitive resin composition for a color filter described above is patterned to have a size of 0.01 mm ２ or less, and the present invention provides a micro LED display that absorbs blue LED light that has not been color-converted by quantum dots by means of the cured film, and extracts only light converted into red or green from each subpixel.

[0039] The cured film obtained from the photosensitive resin composition for a color filter of the present invention can impart high constant temperature and humidity test resistance and chemical resistance that do not affect chromaticity, and also has high adhesion even after a chemical resistance test, and thus can be suitably used for micro LED displays.

[0040] As described above, a photosensitive resin film or a photosensitive dry film formed of the photosensitive resin composition for a color filter of the present invention can easily form fine patterns with excellent perpendicularity through a pattern forming method. Further, the obtained cured film absorbs blue light that has transmitted through the cured quantum dot-containing photoresist film, can selectively extract only red or green light, and can impart high constant temperature and humidity test resistance and chemical resistance that do not affect chromaticity, and also has high adhesion even after a chemical resistance test, and thus can be suitably used for display devices such as micro LED displays.

[0041] As described above, there has been a demand for development of a material that can selectively form a highly reliable layer capable of absorbing blue light only on a cured quantum dot-containing photoresist film that emits red or green light.

[0042] As a result of intensive studies on the above problems, the inventors of the present invention have found that a photosensitive resin composition for a color filter containing the above components (A) to (F) can solve the above problems, and thus completed the present invention.

[0043] That is, the present invention provides a photosensitive resin composition for color filters, which is characterized by comprising: (A) an acrylic resin having a (meth)acryloyl group in a side chain thereof; (B) a dye having an absorption maximum wavelength at 430 to 490 nm; (C) a carbazole-based oxime ester radical generator; (D) a polyfunctional secondary thiol compound; (E) a surfactant; and (F) a solvent.

[0044] Hereinafter, the present invention will be described in detail, but the present invention is not limited thereto.

[0045] [Photosensitive Resin Composition for Color Filters] The photosensitive resin composition for color filters of the present invention comprises (A) an acrylic resin having a (meth)acryloyl group in a side chain thereof, (B) a dye having an absorption maximum wavelength at 430 to 490 nm, (C) an oxime-based photoradical generator, (D) a polyfunctional secondary thiol compound, (E) a surfactant, and (F) a solvent. In addition to the components described above, the composition may further contain component (G) described below and other additives. Hereinafter, each component constituting the photosensitive resin composition for color filters of the present invention will be described.

[0046] [(A) Acrylic Resin Having a (meth)acryloyl Group in a Side Chain Thereof] The acrylic resin (A) having a (meth)acryloyl group in a side chain thereof used in the present invention is not particularly limited. The above-mentioned acrylic resin refers to a polymer of an acrylic ester or a methacrylic ester.

[0047] Component (A) contained in the present invention preferably has a weight average molecular weight Mw in the range of 10,000 to 50,000, and more preferably in the range of 15,000 to 40,000. When component (A) falls within the above range, film thickness reduction of the exposed area is less likely to occur during development, and the solubility of the unexposed area is favorable. The weight average molecular weight is a value determined as a polystyrene-equivalent weight average molecular weight (weight average degree of polymerization) obtained by GPC (gel permeation chromatography) analysis using toluene as a developing solvent at a column temperature of 40°C.

[0048] The double bond equivalent of component (A) is preferably in the range of 200 to 650 g / mol, and more preferably in the range of 250 to 600 g / mol. The double bond equivalent is the weight of resin per acrylic group. If the double bond equivalent of component (A) is within the above range, the crosslinking density is high, and a highly sensitive pattern with a good shape can be formed after development.

[0049] The above component (A) may be used alone or in combination of two or more types. Furthermore, component (A) is preferably present in an amount of 40 to 99% by mass in the nonvolatile components of the color filter photosensitive resin composition. More preferably, it is 50 to 98% by mass.

[0050] [(B) Dye] The (B) dye included in the present invention is not particularly limited as long as it has an absorption maximum wavelength of 430 to 490 nm, but it is preferable that it has good solubility and dispersibility in the (E) solvent described later and the above (A) component.

[0051] Commercially available dyes can be used for this purpose, including, for example, FDB-002 (absorption maximum wavelength 431 nm), FDB-003 (absorption maximum wavelength 438 nm), FDB-004 (absorption maximum wavelength 445 nm), FDB-005 (absorption maximum wavelength 452 nm), and FDB-006 (absorption maximum wavelength 473 nm) from Yamada Chemical Industries, Ltd., FS Yellow 1017 (absorption maximum wavelength 443 nm) from Arimoto Chemical Industries, Ltd., and Dye3 (absorption maximum wavelength 464 nm) and Dye4 (absorption maximum wavelength 479 nm) from Hayashibara Corporation.

[0052] The dye (B) included in the present invention is preferably present in an amount of 0.5 to 15% by mass, and more preferably 1 to 10% by mass, in the nonvolatile components of the photosensitive resin composition for color filters. If the dye content is within the above range, fine patterns can be formed while maintaining good absorption characteristics of blue LED light.

[0053] [(C) Carbazole-based oxime ester radical generator] The (C) component included in the present invention is a (C) carbazole-based oxime ester radical generator and is not particularly limited as long as it is an oxime compound that improves sensitivity during lithography.

[0054] The carbazole oxime ester radical generator described above is preferably a carbazole oxime ester compound. Examples of carbazole oxime ester compounds include N-acetoxy-1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazole-3-yl]ethane-1-imine, N-acetoxy-1-[9-ethyl-6-{2-methyl-4-(3,3-dimethyl-2,4-dioxacyclopentanylmethyloxy)benzoyl}-9H-carbazole-3-yl]ethane-1-imine, and N-acetoxy-1-[9-ethyl-6 Compounds such as -(2-methylbenzoyl)-9H-carbazole-3-yl]-3-cyclopentylpropan-1-imine and N-benzoyloxy-1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazole-3-yl]-3-cyclopentylpropan-1-one-2-imine are examples, as are commercially available products such as ADEKA Arclus N-1919T (manufactured by ADEKA Corporation), NCI-831E (manufactured by ADEKA Corporation), Nikkacure IW-15 (Nippon Chemical Industries, Ltd.), Nikkacure YJ-04(T) (Nippon Chemical Industries, Ltd.), Nikkacure TG-05 (Nippon Chemical Industries, Ltd.), and Nikkacure TG-10 (Nippon Chemical Industries, Ltd.).

[0055] The above-mentioned component (C) is more preferably a carbazole-based oxime ester compound having a maximum absorption wavelength of 350 nm or more, and even more preferably a maximum absorption wavelength of 360 nm or more. Examples include NCI-831E (manufactured by ADEKA Corporation, maximum absorption wavelength 373 nm), Nikkacure IW-15 (manufactured by Nippon Chemical Industries, Ltd., maximum absorption wavelength 372 nm), and Nikkacure YJ-04(T) (manufactured by Nippon Chemical Industries, Ltd., maximum absorption wavelength 370 nm). If the maximum absorption wavelength of component (C) is within the above range, it will have high sensitivity to exposure wavelengths such as i-line, h-line, and g-line during lithography exposure, and radical species will be efficiently generated down to the bottom during lithography, enabling good pattern formation without development peeling. There is no particular upper limit to the maximum absorption wavelength of component (C), but it can be, for example, 430 nm or less.

[0056] The (C) carbazole-based oxime ester radical generator included in the present invention is preferably present in an amount of 0.1 to 1.5% by mass, and more preferably 0.1 to 1.0% by mass, in the non-volatile components of the photosensitive resin composition for color filters. If the content of the oxime-based photoradical generator is within the above range, fine patterns can be formed while maintaining good luminescence characteristics.

[0057] Specifically, component (C) is a carbazole-based oxime ester compound having a maximum absorption wavelength of 350 nm or more, and is preferably present in the non-volatile components of the color filter photosensitive resin composition in an amount of 0.1 to 1.5% by mass.

[0058] [(D) Polyfunctional secondary thiol compound] The component (D) included in the present invention is a (D) polyfunctional secondary thiol compound, and is not particularly limited as long as it is polyfunctional and a secondary thiol compound.

[0059] In the present invention, from the viewpoint of availability, the polyfunctional secondary thiol compound is preferably one or more selected from those represented by the following formulas (D1), (D2), (D3), and (D4). Specifically, the polyfunctional compound only needs to have 2 to 10 functional groups, for example, the functional group may be SH-CHR ２ (R: alkyl group with 1-5 carbon atoms) is an example. Also, if a secondary thiol compound is used, dark reactions will not occur, resulting in gelation or deterioration of patternability.

[0060] In the present invention, the polyfunctional secondary thiol compound may be used alone or in combination of two or more. Furthermore, the polyfunctional secondary thiol compound is preferably present in an amount of 2 to 50% by mass, and more preferably 5 to 40% by mass, in the nonvolatile components of the photosensitive resin composition for the color filter. If the polyfunctional secondary thiol compound is within the above range, curing can be promoted, forming a pattern with good rectangularity and a cured film with high reliability and chemical resistance.

[0061] [(E) Surfactant] The (E) component included in the present invention is a (E) surfactant, and is not particularly limited as long as it improves the applicability, but is preferably a silicone-based surfactant.

[0062] Examples of the above-mentioned silicone-based surfactants include surfactants having siloxane bonds in their molecules. Specifically, examples include Toray Silicone DC3PA, SH7PA, DC11PA, SH21PA, SH28PA, SH29PA, SH30PA, SH8400 (product name: manufactured by Toray Dow Corning Co., Ltd.), KP321, KP322, KP323, KP324, KP326, KP340, KP341 (manufactured by Shin-Etsu Chemical Co., Ltd.), TSF400, TSF401, TSF410, TSF4300, TSF4440, TSF4445, TSF4446, TSF4452, and TSF4460 (manufactured by Momentive Performance Materials Japan LLC).

[0063] The surfactant (E) included in the present invention is preferably present in an amount of 0.001 to 0.7% by mass, and more preferably 0.005 to 0.5% by mass, in the nonvolatile components of the photosensitive resin composition for the color filter. If the surfactant content is within the above range, a film with high flatness can be formed.

[0064] [(F) Solvent] The (F) solvent included in the present invention is not particularly limited as long as it can dissolve and disperse the aforementioned components (A) to (E) and other various additives.

[0065] As the solvent (F) above, organic solvents are preferred, and examples include ketones such as cyclohexanone, cyclopentanone, and methyl-2-n-pentyl ketone; alcohols such as 3-methoxybutanol, 3-methyl-3-methoxybutanol, 1-methoxy-2-propanol, and 1-ethoxy-2-propanol; ethers such as propylene glycol monomethyl ether, ethylene glycol monomethyl ether, propylene glycol monoethyl ether, ethylene glycol monoethyl ether, propylene glycol dimethyl ether, and diethylene glycol dimethyl ether; esters such as propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, ethyl lactate, ethyl pyruvate, butyl acetate, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, tert-butyl acetate, tert-butyl propionate, propylene glycol mono-tert-butyl ether acetate, and γ-butyrolactone. These may be used individually or in combination of two or more.

[0066] As the solvent (F) above, propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether, cyclopentanone, and mixed solvents thereof are preferred, as they have excellent solubility for component (A).

[0067] From the viewpoint of compatibility and viscosity of the photosensitive resin composition for the color filter, the content of component (F) is preferably 25 to 85% by mass, and more preferably 35 to 75% by mass, relative to the total amount of the photosensitive resin composition.

[0068] [(G) Polyfunctional (meth)acrylate] In addition to the components described above, the photosensitive resin composition for color filters of the present invention may further contain (G) polyfunctional acrylate. In this case, the double bond equivalent of the polyfunctional acrylate is preferably 300 g / mol or less, and if it is within the above range, the crosslinking density can be increased to form a pattern with a good shape after development. The lower limit of the double bond equivalent of the (G) polyfunctional (meth)acrylate is not particularly limited, but for example it can be 50 g / mol or more.

[0069] Examples of the above (G) polyfunctional (meth)acrylates include TMPTA, THEIC, PETA, PETTA, DTMP, and DPHA systems, such as dipentaerythritol hexaacrylate (DPHA), isocyanuric acid EO-modified di and triacrylates, Aronics M-315, and Aronics M-940 (manufactured by Toagosei Co., Ltd.).

[0070] The content of component (G) is preferably 15 to 50% by mass relative to the total amount of the photosensitive resin composition for the color filter.

[0071] [Other Additives] In addition to the components (A) to (G) described above, the photosensitive resin composition for color filters of the present invention may also contain other additives. Examples of other additives include silane coupling agents, which are used to improve development adhesion.

[0072] [Photosensitive resin coating] The photosensitive resin coating of the present invention is a dried body of the photosensitive resin composition for color filters described above.

[0073] [Pattern Forming Method Using a Photosensitive Resin Composition for Color Filters] The pattern forming method using the photosensitive resin composition for color filters of the present invention includes the steps of: (i) applying the above-described photosensitive resin composition for color filters onto a substrate to form a photosensitive resin film on the substrate; (ii) exposing the photosensitive resin film to light; and (iii) developing the exposed photosensitive resin film with a developer solution to dissolve and remove the unexposed areas and form a pattern.

[0074] Step (i) is a step of applying the above-described photosensitive resin composition for color filters onto a substrate to form a photosensitive resin film on the substrate. The photosensitive resin film is a dried body of the above-described photosensitive resin composition for color filters. There are no particular restrictions on the substrate, but a substrate having a pattern formed of a quantum dot-containing photoresist capable of emitting red or green fluorescence is preferred, but other examples include glass wafers and quartz wafers.

[0075] The coating method can be any known method, such as the dip method, spin coating method, or roll coating method. The amount to be coated can be appropriately selected depending on the purpose.

[0076] To ensure efficient photocuring, preheating (pre-baking) may be performed to evaporate solvents and other substances beforehand, if necessary. Pre-baking can be carried out, for example, at 60-120°C for 1 minute to 1 hour.

[0077] Next, (ii) the photosensitive resin film is exposed to light. The exposure is preferably carried out with light having a wavelength of 10 to 600 nm, and more preferably with light having a wavelength of 190 to 500 nm. Examples of such wavelengths include light of various wavelengths generated by a radiation generator, such as ultraviolet light (g-rays, h-rays, i-rays, etc.) and far-ultraviolet light (248 nm, 193 nm). Of these, light with a wavelength of 248 to 436 nm is particularly preferred. The exposure dose is 10 to 10,000 mJ / cm². ２ It is preferable.

[0078] Exposure may be performed via a photomask. The photomask may, for example, have a desired pattern cut out of it. The material of the photomask is not particularly limited, but it is preferably one that blocks light of the aforementioned wavelength. For example, one containing chromium as a light-shielding film is preferably used, but is not limited to this.

[0079] (iii) After exposure, the substrate is developed with a developer to form a pattern. Preferred developers include organic solvents such as alcohols such as IPA, ketones such as cyclohexanone, glycols such as propylene glycol monomethyl ether, and known alkaline developers such as aqueous solutions of tetramethylammonium hydroxide. Conventional development methods include the dipping method, in which the patterned substrate is immersed in the developer; the paddle method, in which the developer is dispensed with a paddle; and the spray method, in which the developer is applied with a spray. By developing in this way, the unexposed areas are dissolved and removed, and a pattern is formed. After that, washing, rinsing, drying, etc. are performed as necessary to obtain a cured film having the desired pattern.

[0080] [Photosensitive dry film] The photosensitive dry film of the present invention comprises a support film and a photosensitive resin coating obtained from a photosensitive resin composition for color filters on the support film.

[0081] The photosensitive dry film (support film and photosensitive resin coating) is solid, and since the photosensitive resin coating does not contain solvents, there is no risk of bubbles remaining inside the photosensitive resin coating and between it and the uneven substrate due to its volatilization.

[0082] Furthermore, the viscosity and fluidity of the photosensitive resin film are closely related, and if the photosensitive resin film has an appropriate viscosity range, it can exhibit appropriate fluidity. In other words, with an appropriate viscosity, it can penetrate into narrow gaps to improve adhesion, and the softening of the resin can improve adhesion to the substrate. Therefore, from the viewpoint of the fluidity of the photosensitive resin film, the viscosity of the photosensitive resin film is preferably 10 to 5,000 Pa·s, more preferably 30 to 2,000 Pa·s, at 80 to 120°C. In this invention, viscosity is measured using a rotational viscometer.

[0083] When the photosensitive dry film of the present invention is adhered to an uneven substrate, the photosensitive resin coating follows the contours of the substrate, achieving high flatness. In particular, the photosensitive resin composition for color filters of the present invention is characterized by its softening properties, which enables even higher flatness. Furthermore, when the photosensitive resin coating is adhered to the substrate in a vacuum environment, the occurrence of gaps can be prevented more effectively.

[0084] The photosensitive dry film of the present invention can be manufactured by applying the photosensitive resin composition for color filters onto a substrate and drying it to form a photosensitive resin film. A film coater for manufacturing adhesive products can generally be used as the manufacturing apparatus for the photosensitive dry film. Examples of film coaters include comma coaters, comma reverse coaters, multi coaters, die coaters, lip coaters, lip reverse coaters, direct gravure coaters, offset gravure coaters, three-bottom reverse coaters, four-bottom reverse coaters, and the like.

[0085] A photosensitive dry film can be manufactured by unwinding a support film from the unwinding shaft of the film coater and passing it through the coater head of the film coater, applying the photosensitive resin composition for color filters to a predetermined thickness onto the support film, then passing it through a hot air circulation oven at a predetermined temperature and time to dry it on the support film and form a photosensitive resin coating. Alternatively, if necessary, a photosensitive dry film with a protective film can be manufactured by passing the photosensitive dry film together with a protective film unwinding from another unwinding shaft of the film coater through a laminating roll at a predetermined pressure to bond the photosensitive resin coating on the support film with the protective film, and then winding it onto the winding shaft of the film coater. In this case, the temperature is preferably 50 to 120°C, the time is preferably 1 to 100 minutes, and the pressure is preferably 0.01 to 5 MPa.

[0086] The support film used in the photosensitive dry film of the present invention may be a single-layer film consisting of a single film, or a multilayer film formed by laminating multiple films. Examples of materials for the film include synthetic resin films such as polyethylene, polypropylene, polycarbonate, and polyethylene terephthalate. Of these, polyethylene terephthalate, which has appropriate flexibility, mechanical strength, and heat resistance, is preferred. These films may have undergone various treatments such as corona treatment or coating with a release agent. Commercially available products can be used, such as Therapiel WZ (RX), Therapiel BX8 (R) (both manufactured by Toray Film Processing Co., Ltd.), E7302, E7304 (both manufactured by Toyobo Co., Ltd.), Purex G31, Purex G71T1 (both manufactured by Teijin DuPont Films Ltd.), PET38×1-A3, PET38×1-V8, PET38×1-X08 (all manufactured by Nippa Co., Ltd.).

[0087] The protective film can be the same as the support film described above, but polyethylene terephthalate and polyethylene, which have appropriate flexibility, are preferred. Commercially available products can be used, and examples of polyethylene terephthalate include those already exemplified, while examples of polyethylene include GF-8 (manufactured by Tamapoly Co., Ltd.) and PE film type 0 (manufactured by Nipper Co., Ltd.).

[0088] The thickness of the support film and protective film is preferably 10 to 100 μm, more preferably 25 to 50 μm, from the viewpoint of stability in the production of the photosensitive dry film and prevention of curling on the core.

[0089] [Pattern Forming Method Using Photosensitive Dry Film] The pattern forming method using a photosensitive dry film of the present invention includes the steps of: (i') attaching the photosensitive dry film described above to a substrate to form the photosensitive resin film on the substrate; (ii) exposing the photosensitive resin film to light; and (iii) developing the exposed photosensitive resin film with a developer solution to dissolve and remove the unexposed areas to form a pattern.

[0090] Step (i') is a step of attaching the photosensitive resin coating of the photosensitive dry film to a substrate to form a photosensitive resin coating on the substrate. In other words, a photosensitive resin coating is formed on the substrate by attaching the photosensitive resin coating of the photosensitive dry film to the substrate. There are no particular restrictions on the substrate, but a substrate having a pattern formed of a quantum dot-containing photoresist capable of emitting red or green fluorescence is preferred, but other examples include glass wafers and quartz wafers. Furthermore, if the photosensitive dry film has a protective film, the protective film is peeled off from the photosensitive dry film, and then the photosensitive resin coating of the photosensitive dry film is attached to the substrate. The attachment can be performed, for example, using a film attachment device.

[0091] A vacuum laminator is preferred as the film application device. For example, the protective film of the photosensitive dry film is peeled off, and the exposed photosensitive resin film is pressed onto the substrate on a table at a predetermined temperature using an application roll at a predetermined pressure in a vacuum chamber with a predetermined vacuum level. The temperature is preferably 60 to 120°C, the pressure is preferably 0 to 5.0 MPa, and the vacuum level is preferably 50 to 500 Pa.

[0092] To efficiently carry out the photocuring reaction of the photosensitive resin film and to improve the adhesion between the photosensitive resin film and the substrate, pre-baking may be performed as needed. Pre-baking can be performed, for example, at 60 to 120°C for about 1 minute to 1 hour.

[0093] The photosensitive resin film attached to the substrate can be formed by (ii) exposing the photosensitive resin film to light, (iii) developing it with a developer, dissolving and removing the unexposed areas, and forming a pattern, similar to the pattern formation method using the photosensitive resin composition for color filters. It is preferable to remove the support film of the photosensitive dry film before the development step, depending on the process.

[0094] The present invention provides a photosensitive resin composition for color filters and a pattern-forming method using a dry film, which allows for the easy and selective formation of fine patterns on a pattern formed with a quantum dot-containing photoresist capable of emitting red or green fluorescence.

[0095] [Display Device] The display device of the present invention absorbs blue LED light that was not color-converted by quantum dots using a cured film obtained by the pattern formation method described above, and extracts only the light that has been converted to red or green from each subpixel.

[0096] [Micro LED Display] The micro LED display of the present invention is a 0.01 mm patterned color filter photosensitive resin composition described above. ２The following cured coating absorbs blue LED light that was not color-converted by the quantum dots, and extracts only the light that has been converted to red or green from each subpixel. There is no particular lower limit to the area of ​​the above cured coating, but for example, 2.5 × 10⁻⁶ －５ mm ２ This can be done.

[0097] The present invention will be described more specifically below with reference to examples and comparative examples, but the present invention is not limited to the following examples.

[0098] [1] Preparation and evaluation of photosensitive resin compositions for color filters [Examples 1-6 and Comparative Examples 1-12] Each component was blended according to the amounts listed in Tables 1-3, then stirred and mixed at room temperature, and microfiltration was performed using a 1.0 μm glass filter to obtain the photosensitive resin compositions for color filters of Examples 1-6 and Comparative Examples 1-12.

[0099]

[0100]

[0101]

[0102] In Tables 1 to 3, A-1 to A-2 and A'-1 use the resins listed in Table 4.

[0103]

[0104] In Tables 1-3, A'-2 was synthesized as follows: 265.0 g (1.00 mol) of the following compound (S-5) was added to a 3 L flask equipped with a stirrer, thermometer, nitrogen purging device, and reflux condenser. Then, 2,000 g of toluene was added and the mixture was heated to 70°C. Subsequently, 1.0 g of toluene chloroplatinate solution (platinum concentration 0.5% by mass) was added, and 164.9 g (0.85 mol) of the following compound (S-1) and the following compound (S-2) (y １453.0 g (0.15 mol) of 40 (manufactured by Shin-Etsu Chemical Co., Ltd.) was added dropwise over 1 hour (total hydrosilyl groups / total alkenyl groups = 1 / 1 (molar ratio)). After the dropwise addition was complete, the mixture was heated to 100°C and aged for 6 hours. Toluene was then removed from the reaction solution under reduced pressure, and resin A'-2 with an Mw of 65,000 was obtained by GPC.

[0105] In Tables 1-3, B-1 is FDB-002 (absorption maximum wavelength 431 nm) manufactured by Yamada Chemical Industries, Ltd., B-2 is FS Yellow 1017 (absorption maximum wavelength 443 nm) manufactured by Arimoto Chemical Industries, Ltd., B-3 is FDB-005 (absorption maximum wavelength 452 nm) manufactured by Yamada Chemical Industries, Ltd., B-4 is FDB-006 (absorption maximum wavelength 473 nm) manufactured by Yamada Chemical Industries, Ltd., B'-1 is FDB-009 (absorption maximum wavelength 402 nm) manufactured by Yamada Chemical Industries, Ltd., and B'-2 is FDG-001 (absorption maximum wavelength 503 nm) manufactured by Yamada Chemical Industries, Ltd.

[0106] In Tables 1-3, C-1 is the product name "NCI-831E" (carbazole oxime ester, maximum absorption wavelength 373 nm) manufactured by ADEKA Corporation, C-2 is the product name "Nikkacure IW-15" (carbazole oxime ester, maximum absorption wavelength 372 nm) manufactured by Nippon Chemical Industries, Ltd., C'-1 is the product name "PBG-305" (phenyl sulfide oxime ester, maximum absorption wavelength 328 nm) manufactured by TRONLY, and C'-2 is the product name "Irgacure 819" (acylphosphine oxide, maximum absorption wavelength 380 nm) manufactured by BASF.

[0107] In Tables 1 to 3, D-1 to D-4 and D'-1 and D'-2 are as follows:

[0108] In Tables 1-3, E-1 is the product name "KP341" (silicone-based surfactant) manufactured by Shin-Etsu Chemical Co., Ltd.

[0109] In Tables 1-3, F is PGMEA (propylene glycol monomethyl ether acetate).

[0110] In Tables 1-3, G-1 is "Arronix M-940" (polyfunctional acrylate), a product of Toagosei Co., Ltd., and G-2 is "Arronix M-315" (polyfunctional acrylate), also a product of Toagosei Co., Ltd.

[0111] In Table 3, the product name "CPI-210S" from Sunapro Co., Ltd. was used as the photoacid generator H-1.

[0112] In Table 3, epoxy crosslinking agent I-1 is as follows:

[0113] [2] Preparation of Photosensitive Dry Film A die coater was used as the film coater and polyethylene terephthalate film (38 μm thick) as the support film. The photosensitive resin compositions for color filters described in Tables 1 to 3 were applied to the support film. Next, the films were dried by passing them through a hot air circulation oven (4 m long) set to 80°C for 5 minutes to form a photosensitive resin film on the support film with a thickness of 2 μm, thereby obtaining a photosensitive dry film. A polyethylene film (50 μm thick) was then laminated onto the photosensitive resin film as a protective film using a laminating roll at a pressure of 1 MPa to prepare a photosensitive dry film with a protective film. When peeling off the protective film from the prepared dry film, any area where the photosensitive resin film adhered to the protective film and peeled off from the base film was marked with ×, and any area where there were no problems was marked with ○. The results, along with the viscosity measurement results, are shown in Table 5.

[0114] [3] Pattern Formation and Evaluation First, a substrate was prepared with a pattern formed from a quantum dot-containing photoresist capable of emitting red or green fluorescence as the base material. A'-2:F-1:S-BE030 (maximum fluorescence wavelength 635 nm) manufactured by Shoei Chemical Co., Ltd., G-1:CHIMASSORB 119FL manufactured by BASF, IRGANOX 3114 (BASF), and cyclopentanone were mixed in a ratio of 100:1:100:30:0.1:0.1:231. The mixture was then stirred and mixed at room temperature, and then fine-filtered using a 1.0 μm glass filter to obtain quantum dot-containing photoresist R. Furthermore, quantum dot-containing photoresist G was obtained by replacing the above S-BE030 with S-BE029 (maximum fluorescence wavelength 535 nm) manufactured by Shoei Chemical Co., Ltd. Next, a quantum dot-containing photoresist R or G was coated onto a glass substrate to a thickness of 5 μm using a spin coater. Then, pre-baking was performed on a hot plate at 100°C for 2 minutes. The resulting film was exposed to light at 405 nm through a mask using a contact aligner type exposure apparatus (Süss Microtek's Mask Aligner MA8). After irradiation, spray development was performed with PGMEA for 60 seconds to form an island pattern with sides of 5 cm. Subsequently, post-curing was performed in an oven at 150°C for 2 hours while purging with nitrogen to create a substrate with a pattern formed from a quantum dot-containing photoresist that could emit red or green fluorescence from the underlying substrate.

[0115] The protective film was peeled off the photosensitive dry film with protective film prepared in [2] above, and the vacuum in the vacuum chamber was set to 80 Pa using a vacuum laminator TEAM-100RF (manufactured by Takatori Co., Ltd.), and the photosensitive resin film on the support film was brought into close contact with a substrate having a pattern formed with the aforementioned quantum dot-containing photoresist capable of emitting red or green fluorescence. The temperature condition was 100°C. After returning to atmospheric pressure, the substrate was removed from the vacuum laminator and the support film was peeled off. Next, in order to improve the adhesion to the substrate, pre-baking was performed on a hot plate at 100°C for 2 minutes. To form a square island pattern with a pitch width of 1:1 between adjacent patterns via a mask on the obtained photosensitive resin film, exposure was performed using a contact aligner type exposure apparatus (mask aligner MA8 manufactured by Suss Microtec) at an exposure condition of 405 nm. After irradiation, Examples 2, 4, and 6 and Comparative Examples 1 and 6 were paddle-developed for 90 seconds with a 2.38% aqueous solution of tetramethylammonium hydroxide, while the others were paddle-developed for 90 seconds with propylene glycol monomethyl ether to form patterns on the quantum dot-containing photoresist cured film. Subsequently, island patterns with sides of 50 μm, 20 μm, 10 μm, 5 μm, and 3 μm were observed using a scanning electron microscope (SEM), and the smallest pattern size that was not connected to an adjacent island pattern (pitch width of 1:1) was defined as the limiting resolution. The perpendicularity of the patterns was also evaluated, with vertical patterns (80° ≤ taper angle ≤ 100°) being marked as ○, and tapered shapes (80° > taper angle, 100° < taper angle) or poor aperture being marked as ×. The results are shown in Tables 6 to 9.

[0116] [4] As a chromaticity measurement substrate, a substrate with a pattern formed from a quantum dot-containing photoresist capable of emitting red or green fluorescence was used, and an island pattern with sides of 5 cm was formed on the quantum dot-containing photoresist cured film in the same manner as described above. Then, while illuminating the back side of the substrate with blue LED light, the chromaticity was measured from the front side using a spectroradiometer MK350S PREMIUM (manufactured by UPRtek). If x ≥ 0.5 (red region), it was marked as red; if y ≥ 0.5 (green region), it was marked as green; and otherwise, it was marked as ×. The chromaticity measurement result of the substrate itself with the pattern formed from a quantum dot-containing photoresist capable of emitting red fluorescence was designated as Ref. R, and the chromaticity measurement result of the substrate itself with the pattern formed from a quantum dot-containing photoresist capable of emitting green fluorescence was designated as Ref. G. The results are shown in Tables 6 to 9.

[0117] [5] Constant Temperature and Humidity Test Using the substrates from which the chromaticity measurement described above was performed, a constant temperature and humidity test was conducted by treating them under conditions of 85°C / 85%RH for 500 hours, and the chromaticity measurement was performed again. A change of 0.03 or more in x or y during the constant temperature and humidity test was marked with ×, and a change less than that was marked with ○. The results are shown in Tables 6 to 9.

[0118] [6] Chemical Resistance Test Using the substrates from the chromaticity measurement described in [4] above, a chemical resistance test was performed by immersing them in propylene glycol monomethyl ether for one hour, and then the chromaticity measurement was performed again. A change of 0.03 or more in x or y after the chemical resistance test was marked with ×, and a change less than that was marked with ○. The results are shown in Tables 6 to 9.

[0119] [6] Adhesion Test Using the substrates that underwent the chemical resistance test described above, a grid peel test (JIS K 5400) was performed. A result was marked with × if even one peel was found, and ○ if no peeling occurred. The results are shown in Tables 6-9.

[0120]

[0121]

[0122]

[0123]

[0124]

[0125] Based on the above results, the photosensitive resin composition of the present invention has lithographic performance that enables the formation of good photosensitive films and photosensitive dry films, and allows for the easy formation of fine and highly perpendicular patterns. Furthermore, the resulting cured film absorbs the blue light that has been transmitted through the quantum dot-containing photoresist cured film, selectively and efficiently extracting only red or green light, and provides high constant temperature and humidity test resistance and chemical resistance without affecting chromaticity. In addition, it maintains high adhesion even after chemical resistance testing, making it suitable for use in display devices such as micro-LED displays.

[0126] On the other hand, in Comparative Example 1, which differed from the present invention in component (A), Comparative Example 2, which did not contain component (D), Comparative Examples 3 and 4, which differed in component (D), Comparative Examples 5 and 6, which differed in component (C), Comparative Examples 7 and 8, which differed in component (B), and Comparative Examples 9 to 12, which differed in component (A) and did not contain component (C), it was not possible to form a cured film with high rectangularity and resolution. Furthermore, the constant temperature and humidity test resistance and chemical resistance were inferior, and the adhesion was insufficient, so a cured film suitable for use as a display device could not be obtained.

[0127] This specification includes the following embodiments: [1] A photosensitive resin composition for color filters, characterized by comprising: (A) an acrylic resin having (meth)acryloyl groups in its side chains; (B) a dye having an absorption maximum wavelength of 430 to 490 nm; (C) a carbazole oxime ester radical generator; (D) a polyfunctional secondary thiol compound; (E) a surfactant; and (F) a solvent. [2] The photosensitive resin composition for color filters according to [1], characterized in that the component (D) is one or more selected from those represented by the following formulas (D1), (D2), (D3), and (D4). [3]: The photosensitive resin composition for color filters according to [1] or [2] above, characterized in that component (A) has a weight-average molecular weight Mw of 10,000 to 50,000 and a double bond equivalent of 200 to 650 g / mol. [4]: ​​The photosensitive resin composition for color filters according to any one of [1] to [3] above, characterized in that component (B) is contained in the nonvolatile components of the photosensitive resin composition for color filters in an amount of 0.5 to 15% by mass. [5]: The photosensitive resin composition for color filters according to any one of [1] to [4] above, characterized in that component (C) is a carbazole oxime ester compound having a maximum absorption wavelength of 350 nm or more, and is contained in the nonvolatile components of the photosensitive resin composition for color filters in an amount of 0.1 to 1.5% by mass. [6]: The photosensitive resin composition for color filters according to any one of [1] to [5] above, characterized in that the (D) component is contained in the nonvolatile components of the photosensitive resin composition for color filters in an amount of 2 to 50% by mass. [7]: The photosensitive resin composition for color filters according to any one of [1] to [6] above, further characterized in that it contains (G) a polyfunctional (meth)acrylate having a double bond equivalent of 300 g / mol or less. [8]: The photosensitive resin composition for color filters according to any one of [1] to [7] above, characterized in that the photosensitive resin composition for color filters absorbs blue LED light transmitted through a quantum dot-containing photoresist cured film capable of emitting red or green fluorescence. [9]: A photosensitive resin film characterized in that it is a dried body of the photosensitive resin composition for color filters according to any one of [1] to [8] above.

[10] : A photosensitive dry film comprising a support film and a photosensitive resin coating as described in [9] above on the support film.

[11] : A pattern forming method comprising: (i) applying a photosensitive resin composition for color filters described in any one of the above items [1] to [8] onto a substrate to form a photosensitive resin film on the substrate; (ii) exposing the photosensitive resin film to light; and (iii) developing the exposed photosensitive resin film with a developer solution to dissolve and remove the unexposed areas and form a pattern.

[12] : A pattern forming method comprising: (i') attaching a photosensitive dry film described in the above item

[10] onto a substrate to form a photosensitive resin film on the substrate; (ii) exposing the photosensitive resin film to light; and (iii) developing the exposed photosensitive resin film with a developer solution to dissolve and remove the unexposed areas and form a pattern.

[13] : The pattern formation method according to

[11] , characterized in that the substrate is a substrate having a pattern formed of a quantum dot-containing photoresist capable of emitting red or green fluorescence.

[14] : The pattern formation method according to

[12] , characterized in that the substrate is a substrate having a pattern formed of a quantum dot-containing photoresist capable of emitting red or green fluorescence.

[15] : A display device characterized in that a cured film patterned with the photosensitive resin composition for color filters according to any one of [1] to [8] absorbs blue LED light that has not been color-converted by quantum dots, and extracts only the light that has been converted to red or green from each subpixel.

[16] : A 0.01 mm patterned film of the photosensitive resin composition for color filters according to any one of [1] to [8]. ２ A microLED display characterized by the following cured coating which absorbs blue LED light that was not color-converted by quantum dots, and extracts only the light that has been converted to red or green from each subpixel.

[0128] It should be noted that the present invention is not limited to the embodiments described above. The embodiments described above are illustrative, and any configuration that is substantially identical to the technical idea described in the claims of the present invention and achieves similar effects is included within the technical scope of the present invention.

Claims

1. A photosensitive resin composition for color filters, characterized by comprising: (A) an acrylic resin having (meth)acryloyl groups in its side chains; (B) a dye having an absorption maximum wavelength of 430 to 490 nm; (C) a carbazole-based oxime ester radical generator; (D) a polyfunctional secondary thiol compound; (E) a surfactant; and (F) a solvent.

2. The photosensitive resin composition for color filters according to claim 1, characterized in that the (D) component is one or more selected from those represented by the following formulas (D1), (D2), (D3), and (D4).

3. The photosensitive resin composition for color filters according to claim 1, characterized in that component (A) has a weight-average molecular weight Mw of 10,000 to 50,000 and a double bond equivalent of 200 to 650 g / mol.

4. The photosensitive resin composition for color filters according to claim 1, characterized in that the component (B) is contained in 0.5 to 15% by mass of the nonvolatile components of the photosensitive resin composition for color filters.

5. The photosensitive resin composition for color filters according to claim 1, characterized in that the (C) component is a carbazole-based oxime ester compound having a maximum absorption wavelength of 350 nm or more, and is contained in the nonvolatile components of the photosensitive resin composition for color filters in an amount of 0.1 to 1.5% by mass.

6. The photosensitive resin composition for color filters according to claim 1, characterized in that the (D) component is contained in the nonvolatile components of the photosensitive resin composition for color filters in an amount of 2 to 50% by mass.

7. The photosensitive resin composition for color filters according to claim 1, further characterized in that it contains (G) a polyfunctional (meth)acrylate having a double bond equivalent of 300 g / mol or less.

8. The photosensitive resin composition for color filters according to claim 1, characterized in that the photosensitive resin composition for color filters absorbs blue LED light transmitted through a photoresist cured film containing quantum dots capable of emitting red or green fluorescence.

9. A photosensitive resin film characterized by being a dried body of the photosensitive resin composition for color filters described in any one of claims 1 to 8.

10. A photosensitive dry film comprising a support film and a photosensitive resin coating according to claim 9 on the support film.

11. A pattern forming method comprising: (i) applying a photosensitive resin composition for color filters according to any one of claims 1 to 8 onto a substrate to form a photosensitive resin film on the substrate; (ii) exposing the photosensitive resin film to light; and (iii) developing the exposed photosensitive resin film with a developer solution to dissolve and remove the unexposed areas to form a pattern.

12. A pattern forming method comprising: (i') a step of attaching the photosensitive dry film described in claim 10 to a substrate to form the photosensitive resin film on the substrate; (ii) a step of exposing the photosensitive resin film to light; and (iii) a step of developing the exposed photosensitive resin film with a developer solution to dissolve and remove the unexposed areas to form a pattern.

13. The pattern formation method according to claim 11, characterized in that the substrate is a substrate having a pattern formed of a quantum dot-containing photoresist capable of emitting red or green fluorescence.

14. The pattern formation method according to claim 12, characterized in that the substrate is a substrate having a pattern formed of a quantum dot-containing photoresist capable of emitting red or green fluorescence.

15. A display device characterized in that the photosensitive resin composition for color filters according to any one of claims 1 to 8 is patterned and cured to absorb blue LED light that was not color-converted by quantum dots, and extracts only the light that has been converted to red or green from each subpixel.

16. A 0.01 mm patterned photosensitive resin composition for color filters according to any one of claims 1 to 8. ２ A microLED display characterized by the following cured coating which absorbs blue LED light that was not color-converted by quantum dots, and extracts only the light that has been converted to red or green from each subpixel.

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