Photosensitive colored composition, method for producing a photosensitive colored composition, and method for producing an infrared light cut filter

Abstract

To provide a photosensitive coloring composition, an infra-red light cut filter, a manufacturing method of a photosensitive coloring composition and a manufacturing method of an infra-red light cut filter, capable of preventing a deterioration in absorbancy at an infra-red light cut filter formed by a photosensitive coloring composition and a deterioration in precision at a pattern shape.SOLUTION: A photosensitive coloring composition includes a coloring agent, a photoinitiator, a photo polymerizable monomer, and an acrylic copolymer. In the acrylic copolymer, based on a total weight of the acrylic copolymer, a sum total of a weight of a first repeating unit, a weight of a second repeating unit and a weight of a third repeating unit is 87.5 to 100 wt.%. The weight of the first repeating unit is 10 to 20 wt.%, the weight of the second repeating unit is 12.5 to 20 wt.%, and the weight of the third repeating unit is 65 wt.% or more.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a photosensitive colored composition. , feeling This invention relates to a method for producing a photochromic composition and a method for producing an infrared light cut filter. [Background technology]

[0002] Digital cameras are equipped with solid-state image sensors such as CCD (Charge Coupled Device) image sensors and CMOS (Complementary Metal Oxide Semiconductor) image sensors. Solid-state image sensors are equipped with infrared light cut-off filters. The infrared light cut-off filter absorbs infrared light incident on it, thereby preventing infrared light from being incident on the photoelectric conversion element on the opposite side of the infrared light cut-off filter from the light incident side. This improves the accuracy of visible light detection by the photoelectric conversion element. As a result, noise in the visible light detected by the solid-state image sensor is reduced, and consequently, the color reproduction accuracy of images captured by the solid-state image sensor is improved.

[0003] Solid-state image sensors capable of detecting not only visible light but also infrared light have also been proposed. When a solid-state image sensor is capable of detecting both infrared light and visible light, it is equipped with the infrared light cut filter and the infrared light transmission filter described above.

[0004] Infrared light cut filters are formed by the following methods. For example, an infrared light cut filter is formed by adding an inorganic substance that absorbs infrared light to glass. Alternatively, an infrared light cut filter is formed by coating a substance that absorbs infrared light onto a glass plate. Another method is to use a colored resin composition containing a dye that absorbs infrared light. The method using a colored resin composition is advantageous compared to the method using glass in terms of processability and thin-film formation of the infrared light cut filter (see, for example, Patent Documents 1 and 2). [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2013-20000 [Patent Document 2] Patent No. 6395293 [Overview of the project] [Problems that the invention aims to solve]

[0006] Incidentally, the coloring agent included in the colored resin composition can be a dye with high dispersibility within the colored resin composition. By using a highly dispersible dye, it is possible to suppress the roughness of the surface of the infrared light cut filter formed from the colored resin composition, and the formation of irregularities on the surface of the infrared light cut filter caused by particles formed from the coloring agent.

[0007] On the other hand, within a colored resin composition, dyes may absorb light in a wavelength range different from the wavelength range originally expected of the dye due to association with nearby dyes. As a result, the absorbance in the wavelength range originally expected of the colorant may decrease in an infrared light cut filter formed using a colored resin composition.

[0008] Furthermore, when forming an infrared light cut filter using a colored resin composition, the coating film formed using the colored resin composition is heated in order to cure the colored resin composition. When dyes are used as colorants, the accuracy of the pattern shape required for the infrared light cut filter may decrease. For example, when forming a rectangular hole in an infrared light cut filter, thermal sagging may occur, causing the corners formed by the infrared light cut filter and the side surface defining the rectangular hole to become rounded. Since the infrared light cut filter in a solid-state image sensor is very fine, thermal sagging reduces the film thickness of the infrared light cut filter, thereby degrading its performance. [Means for solving the problem]

[0009] A photosensitive coloring composition for solving the above problems comprises a coloring agent which is a dye having an absorption maximum in the wavelength band of 700 nm to 1100 nm, a photopolymerization initiator, a photopolymerizable monomer, and an acrylic copolymer. The acrylic copolymer comprises a first repeating unit represented by the following formula (1) and containing an epoxy group, a second repeating unit represented by the following formula (2) and derived from acrylic acid or methacrylic acid, and a third repeating unit represented by the following formula (3) and containing an aromatic ring, wherein the sum of the weights of the first repeating unit, the second repeating unit, and the third repeating unit with respect to the total weight of the acrylic copolymer is 87.5% by weight or more and 100% by weight or less, the weight of the first repeating unit is 10% by weight or more and 20% by weight or less, the weight of the second repeating unit is 12.5% ​​by weight or more and 20% by weight or less, and the weight of the third repeating unit is 65% by weight or more.

[0010] [ka]

[0011] However, in formula (1), R1 is a hydrogen atom or a methyl group, R2 is a single bond, a linear alkylene group having 1 or more carbon atoms, or a branched alkylene group having 3 or more carbon atoms. R3 is an epoxy group.

[0012]

Chemical formula

[0013] However, in formula (2), R4 is a hydrogen atom or a methyl group.

[0014]

Chemical formula

[0015] However, in formula (3), R5 is a hydrogen atom or a methyl group, R6 is a single bond, a linear alkylene group having 1 or more carbon atoms, a branched alkylene group having 3 or more carbon atoms, or an oxyalkylene group having 1 or more carbon atoms. R7 is a hydrogen atom or a predetermined substituent. In formula (3), when R7 is a substituent, m is an integer of any one from 1 to 5.

[0016] According to the above photosensitive coloring composition, in the acrylic copolymer, the first repeating unit, the second repeating unit, and the third repeating unit are each included within the above-described ranges, so that the heat sag of the cured film due to heat treatment is suppressed, and thereby, it is possible to suppress a decrease in the accuracy of the shape of the pattern formed on the cured film. Further, in the photosensitive coloring composition, the aggregation of the colorant is suppressed, and thereby, a decrease in the absorbance at the wavelength where absorption is expected in the colorant is suppressed.

[0017] In the above photosensitive coloring composition, the ratio of the weight of the photopolymerizable monomer to the weight of the acrylic copolymer may be 0.4 or more and 0.7 or less, and the ratio of the weight of the photoinitiator to the weight of the photopolymerizable monomer may be 0.03 or more and 0.08 or less.

[0018] According to the above photosensitive coloring composition, the ratio of the weight of the photopolymerizable monomer to the weight of the acrylic copolymer is within the range of 0.4 to 0.7, and the ratio of the weight of the photopolymerization initiator to the weight of the photopolymerizable monomer is within the range of 0.03 to 0.08, thereby improving the accuracy of the pattern shape. Furthermore, the aggregation of colorants is suppressed in the photosensitive coloring composition, thereby suppressing the decrease in absorbance at wavelengths where absorption is expected in the colorants.

[0019] In the above-described photosensitive coloring composition, the average molecular weight of the acrylic copolymer may be 8,000 or more and 30,000 or less. With this photosensitive coloring composition, since the average molecular weight of the acrylic copolymer is within the range of 8,000 or more and 30,000 or less, when a cured film is formed using the photosensitive coloring composition, it is possible to further suppress the decrease in absorbance of the cured film at wavelengths in which absorption is expected in the colorant contained in the cured film.

[0020] The above-mentioned photosensitive coloring composition may also include a dissolution rate of 20 nm / second or more in an alkaline developer at 23°C. With this photosensitive coloring composition, a dissolution rate of 20 nm / second or more makes it possible to improve the accuracy of the pattern shape even when forming fine patterns.

[0021] In the above photosensitive colored composition, the colorant may be selected from the group consisting of cyanine dyes, phthalocyanine dyes, squarylium dyes, crokonium dyes, diimonium dyes, dithiol metal complex dyes, naphthalocyanine dyes, and oxonol dyes.

[0022] In the above-described photosensitive coloring composition, the coloring agent may be the cyanine dye. This photosensitive coloring composition makes it possible to increase the solubility of the coloring agent in the solvent and to increase the molar extinction coefficient of the coloring agent.

[0023] An infrared light cut filter for solving the above problems comprises a colorant which is a dye having an absorption maximum in the wavelength band of 700 nm to 1100 nm, an acrylic copolymer, and a polymer different from the acrylic copolymer. The acrylic copolymer comprises a first repeating unit represented by formula (1) and containing an epoxy group, a second repeating unit represented by formula (2) and derived from acrylic acid or methacrylic acid, and a third repeating unit represented by formula (3) and containing an aromatic ring. In the acrylic copolymer, the sum of the weights of the first repeating unit, the second repeating unit, and the third repeating unit with respect to the total weight of the acrylic copolymer is 87.5% by weight or more and 100% by weight or less, the weight of the first repeating unit is 10% by weight or more and 20% by weight or less, the weight of the second repeating unit is 12.5% ​​by weight or more and 20% by weight or less, and the weight of the third repeating unit is 65% by weight or more.

[0024] A method for producing a photosensitive colored composition to solve the above problems comprises mixing a colorant, a photopolymerization initiator, a photopolymerizable monomer, and an acrylic copolymer. The colorant is a dye having an absorption maximum in a wavelength band of 700 nm to 1100 nm. The acrylic copolymer comprises a first repeating unit represented by formula (1) and containing an epoxy group, a second repeating unit represented by formula (2) and derived from acrylic acid or methacrylic acid, and a third repeating unit represented by formula (3) and containing an aromatic ring. In the acrylic copolymer, the sum of the weights of the first repeating unit, the second repeating unit, and the third repeating unit with respect to the total weight of the acrylic copolymer is 87.5% by weight or more and 100% by weight or less, the weight of the first repeating unit is 10% by weight or more and 20% by weight or less, the weight of the second repeating unit is 12.5% ​​by weight or more and 20% by weight or less, and the weight of the third repeating unit is 65% by weight or more.

[0025] A method for manufacturing an infrared light cut filter to solve the above problems includes applying a photosensitive colored composition manufactured by the above method for manufacturing a photosensitive colored composition to a substrate to form a coating film, exposing the coating film by irradiating a part of the coating film with light, developing the coating film after exposure, and curing the coating film by heating the coating film after development. [Effects of the Invention]

[0026] According to the present invention, it is possible to suppress the decrease in absorbance and the decrease in the accuracy of the pattern shape in an infrared light cut filter formed from a photosensitive colored composition. [Brief explanation of the drawing]

[0027] [Figure 1] This is an exploded perspective view showing the layer structure of one embodiment of a solid-state image sensor. [Figure 2] This table shows the blending ratios of acrylic monomers in production examples 1 to 10 of the acrylic copolymer. [Figure 3] This table shows the mixing ratios in the photosensitive colored compositions of Examples 1 to 18 and Comparative Examples 1 to 3. [Figure 4] This table shows the evaluation results for Examples 1 to 18 and Comparative Examples 1 to 3. [Figure 5] This is a triangular diagram showing the relationship between the weight of the first repeating unit, the weight of the second repeating unit, and the weight of the third repeating unit. [Figure 6] This graph shows the relationship between the first ratio and the second ratio. [Modes for carrying out the invention]

[0028] Referring to Figures 1 and 2, a photosensitive colored composition, an infrared light cut filter, a method for producing the photosensitive colored composition, and one embodiment of the infrared light cut filter will be described. [Solid-state image sensor] The solid-state image sensor will be explained with reference to Figure 1. Figure 1 is a schematic diagram showing the individual layers of a part of the solid-state image sensor separated.

[0029] As shown in Figure 1, the solid-state image sensor 10 comprises a solid-state image sensor filter 10F and a plurality of photoelectric conversion elements 11. The plurality of photoelectric conversion elements 11 include a red photoelectric conversion element 11R, a green photoelectric conversion element 11G, a blue photoelectric conversion element 11B, and an infrared photoelectric conversion element 11P. Each of the photoelectric conversion elements 11R, 11G, and 11B for each color measures the intensity of visible light having a specific wavelength associated with that photoelectric conversion element 11R, 11G, and 11B. Each infrared photoelectric conversion element 11P measures the intensity of infrared light.

[0030] The solid-state image sensor 10 comprises a plurality of red photoelectric conversion elements 11R, a plurality of green photoelectric conversion elements 11G, a plurality of blue photoelectric conversion elements 11B, and a plurality of infrared photoelectric conversion elements 11P. In Figure 1, for illustrative purposes, the repeating units of the photoelectric conversion elements 11 in the solid-state image sensor 10 are shown.

[0031] The solid-state image sensor filter 10F comprises multiple visible light filters, an infrared light pass filter 12P, an infrared light cut filter 13, a barrier layer 14, multiple visible light microlenses, and an infrared light microlens 15P.

[0032] The visible light color filter consists of a red filter 12R, a green filter 12G, and a blue filter 12B. The red filter 12R is located on the light incident side relative to the red photoelectric conversion element 11R. The green filter 12G is located on the light incident side relative to the green photoelectric conversion element 11G. The blue filter 12B is located on the light incident side relative to the blue photoelectric conversion element 11B.

[0033] The infrared light pass filter 12P is located on the light incident side with respect to the infrared light photoelectric converter 11P. The infrared light pass filter 12P cuts out visible light that the infrared light photoelectric converter 11P can detect. This improves the detection accuracy of infrared light by the infrared light photoelectric converter 11P. The infrared light that the infrared light photoelectric converter 11P can detect is, for example, near-infrared light.

[0034] The infrared light cut filter 13 is located on the light incidence side relative to the respective color filters 12R, 12G, and 12B. The infrared light cut filter 13 has a through hole 13H. When viewed from a viewpoint opposite to the plane on which the infrared light cut filter 13 extends, the infrared light pass filter 12P is located within the region demarcated by the through hole 13H. On the other hand, when viewed from a viewpoint opposite to the plane on which the infrared light cut filter 13 extends, the infrared light cut filter 13 is located on the red filter 12R, the green filter 12G, and the blue filter 12B.

[0035] The infrared light cut filter 13 contains a coloring agent. The coloring agent has the maximum absorption rate of infrared light at any wavelength included in the near-infrared light spectrum. Therefore, the infrared light cut filter 13 can reliably absorb near-infrared light passing through it. As a result, near-infrared light that can be detected by the photoelectric conversion elements 11 for each color is sufficiently cut off by the infrared light cut filter 13. The infrared light cut filter 13 can have a thickness of, for example, 300 nm or more and 3 μm or less.

[0036] The barrier layer 14 suppresses the transmission of oxidation sources through the infrared light cut filter 13. Oxidation sources include oxygen and water. The oxygen permeability of the barrier layer 14 is, for example, 5.0 cc / m³. 2 It is preferable that the oxygen permeability is less than or equal to / day / atm. The oxygen permeability is a value in accordance with JIS K7126:2006. Oxygen permeability of 5.0 cc / m³ 2Since the temperature is set to less than / day / atm, the barrier layer 14 prevents oxidation sources from reaching the infrared light cut filter 13, making the infrared light cut filter 13 less susceptible to oxidation by oxidation sources. Therefore, the light resistance of the infrared light cut filter 13 can be improved.

[0037] The material forming the barrier layer 14 is an inorganic compound. Preferably, the material forming the barrier layer 14 is a silicon compound. The material forming the barrier layer 14 may be at least one selected from the group consisting of silicon nitride, silicon oxide, and silicon oxynitride.

[0038] The microlenses consist of a red microlens 15R, a green microlens 15G, a blue microlens 15B, and an infrared microlens 15P. The red microlens 15R is located on the incident side of the red filter 12R. The green microlens 15G is located on the incident side of the green filter 12G. The blue microlens 15B is located on the incident side of the blue filter 12B. The infrared microlens 15P is located on the incident side of the infrared light pass filter 12P.

[0039] Each microlens 15R, 15G, 15B, and 15P has an incident surface 15S, which is its outer surface. Each microlens 15R, 15G, 15B, and 15P has a refractive index difference between itself and the outside air to focus the light entering the incident surface 15S toward each photoelectric conversion element 11R, 11G, 11B, and 11P. Each microlens 15R, 15G, 15B, and 15P contains a transparent resin.

[0040] [Photosensitive coloring composition] The photosensitive colored composition of this disclosure comprises a colorant, a photopolymerization initiator, a photopolymerizable monomer, and an acrylic copolymer. The colorant has an absorption maximum in the wavelength band between 700 nm and 1100 nm. The acrylic copolymer comprises a first repeating unit, a second repeating unit, and a third repeating unit. The first repeating unit is represented by the following formula (1) and contains an epoxy group. The second repeating unit is represented by the following formula (2) and is derived from acrylic acid or methacrylic acid. The third repeating unit is represented by the following formula (3) and contains an aromatic ring.

[0041] [ka]

[0042] However, in formula (1), R1 is a hydrogen atom or a methyl group, and R2 is a single bond, a linear alkylene group having 1 or more carbon atoms, or a branched alkylene group having 3 or more carbon atoms. R3 is an epoxy group.

[0043] [ka]

[0044] However, in formula (2), R4 is either a hydrogen atom or a methyl group.

[0045] [ka]

[0046] However, in formula (3), R5 is a hydrogen atom or a methyl group, and R6 is a single bond, a linear alkylene group having 1 or more carbon atoms, a branched alkylene group having 3 or more carbon atoms, or an oxyalkylene group having 1 or more carbon atoms. R7 is a hydrogen atom or a predetermined substituent. In formula (3), if R7 is a substituent, m is an integer from 1 to 5.

[0047] In an acrylic copolymer, the sum of the weights of the first repeating unit, the second repeating unit, and the third repeating unit relative to the total weight of the acrylic copolymer is 87.5% by weight or more and 100% by weight or less. The weight of the first repeating unit is 10% by weight or more and 20% by weight or less, the weight of the second repeating unit is 12.5% ​​by weight or more and 20% by weight or less, and the weight of the third repeating unit is 65% by weight or more.

[0048] In the acrylic copolymer, since the first repeating unit, the second repeating unit, and the third repeating unit are each within the range described above, thermal deformation of the cured film caused by heat treatment is suppressed, thereby preventing a decrease in the accuracy of the pattern shape formed on the cured film. Furthermore, in the photosensitive colored composition, the aggregation of colorants is suppressed, thereby preventing a decrease in absorbance at wavelengths where absorption is expected in the colorants.

[0049] The epoxy groups of the first repeating unit and the carboxyl groups of the second repeating unit form a cross-linked structure during the heating process when curing the photosensitive colored composition to form a cured film. This enhances the heat resistance of the coating film formed from the photosensitive colored composition. As a result, the reduction in accuracy of the pattern shape required for infrared light cut filters is suppressed. In particular, when forming rectangular holes in an infrared light cut filter, heat sagging that causes rounding of the corners formed by the infrared light cut filter and the side surface defining the rectangular hole is suppressed.

[0050] Furthermore, because the carboxyl groups in the second repeating unit are acidic, the coating film formed from the photosensitive coloring composition dissolves in an alkaline developer. Therefore, the inclusion of a photopolymerization initiator and a photopolymerizable monomer in the photosensitive coloring composition allows for patterning of the coating film.

[0051] Furthermore, the aromatic rings of the third repeating unit are positioned between the colorant and other colorants located in its vicinity, thereby creating a distance between the colorants sufficient to suppress their aggregation. This suppresses the decrease in absorbance at wavelengths where absorption is expected in the colorant, in other words, the increase in transmittance. As a result, the decrease in absorbance in the cured film formed using the photosensitive colorant composition is suppressed.

[0052] The materials contained in the photosensitive coloring composition will be described in detail below. [Coloring agent] As described above, the colorant has an absorption maximum in the wavelength range of 700 nm to 1100 nm. In the colorant, the molar extinction coefficient ε(mol) at the wavelength in which the colorant has an absorption maximum is -1 L cm -1 It is preferable that ) satisfies the following equation. ε≧3.0×10 4

[0053] With the miniaturization and weight reduction of solid-state image sensors, infrared light cut filters used in solid-state image sensors are required to have a film thickness of several hundred nanometers or more and several micrometers or less. The molar extinction coefficient of the colorant is 3.0 × 10⁻⁶ 4 As described above, it is possible to prepare a photosensitive colored composition that can achieve the absorbance required for a thin-film infrared light cut filter. For example, in an optical filter with a thickness of 1 μm, it is possible to prepare a colored resin composition such that the transmittance at the wavelength in which the colorant has an absorption maximum is 10% or less. Furthermore, since it is possible to reduce the proportion of the colorant in the total amount of the photosensitive colored composition, the photosensitive resin composition can contain many copolymers and solvents. It should also be noted that the photosensitive colored composition may contain other components besides the colorant, copolymer, and solvent. These other components may be, for example, crosslinking agents or polymerizable monomers.

[0054] In contrast, the molar extinction coefficient of the colorant is 3.0 × 10 4If the value is smaller than this, the photosensitive colored composition needs to contain a large amount of colorant to exhibit a predetermined absorbance, which can make it difficult for the photosensitive colored composition to contain a copolymer sufficient to have the desired viscosity. As a result, it becomes difficult to form a coating film of the desired thickness, and consequently, an infrared light cut filter.

[0055] The coloring agent may be, for example, any of the following: cyanine dyes, phthalocyanine dyes, squarylium dyes, crokonium dyes, diimonium dyes, dithiol metal complex dyes, naphthalocyanine dyes, oxonol dyes, and pyrometene dyes. Note that all of these dyes are dyes.

[0056] It is also possible to use pigments as colorants in the photosensitive resin composition. However, when pigments are used, their dispersibility in the photosensitive resin composition is low, making it difficult to disperse the pigments and maintain their dispersed state. As a result, the pigments tend to aggregate in the photosensitive resin composition, and the viscosity of the photosensitive colored composition tends to increase. In this respect, when dyes are used as colorants, aggregation in the photosensitive resin composition is suppressed, and the increase in viscosity of the photosensitive colored composition is also suppressed.

[0057] Furthermore, when the photosensitive coloring composition contains a pigment, the pigment has high thermal stability, which enhances the heat resistance of the cured film. Therefore, when the photosensitive coloring composition contains a pigment, the accuracy of the pattern shape does not decrease.

[0058] The colorant is preferably a cyanine dye due to its high solubility in the solvent and high molar extinction coefficient. The cyanine dye comprises polymethine, a cation having two nitrogen-containing heterocycles located one at each end of the polymethine, and tris(pentafluoroethyl)trifluorophosphate. The cyanine dye may have the structure shown in formula (4) below.

[0059] [ka]

[0060] In formula (4) above, X is one methine or polymethine. The hydrogen atoms bonded to the carbon atoms in the methine may be substituted with halogen atoms or organic groups. The polymethine may have a cyclic structure containing carbon atoms that form the polymethine. The cyclic structure may include three consecutive carbon atoms in the multiple carbon atoms that form the polymethine. If the polymethine has a cyclic structure, the number of carbon atoms in the polymethine may be five or more. Each nitrogen atom is contained in a five-membered or six-membered heterocycle. The heterocycle may be fused. In formula (4) above, Y - It is an anion.

[0061] Furthermore, the cyanine dye may have the structure shown in formula (5) below.

[0062] [ka]

[0063] In formula (5) above, n is an integer of 1 or more. n indicates the number of repeating units contained in the polymethine chain. R10 and R11 are hydrogen atoms or organic groups. R12 and R13 are hydrogen atoms or organic groups. R12 and R13 are preferably linear alkyl groups having 1 or more carbon atoms, or branched alkyl groups. Each nitrogen atom is contained in a five-membered ring or a six-membered ring heterocycle. The heterocycle may be fused.

[0064] In formula (4), if the polymethine includes a cyclic structure, the cyclic structure may be, for example, a cyclic structure having at least one unsaturated bond, such as an ethylenic double bond, and where the unsaturated bond resonates electronically as part of the polymethine chain. Such cyclic structures may be, for example, a cyclopentene ring, a cyclopentadiene ring, a cyclohexene ring, a cyclohexadiene ring, a cycloheptene ring, a cyclooctene ring, a cyclooctadiene ring, and a benzene ring. All of these cyclic structures may have substituents.

[0065] Furthermore, in equation (5), the compound with n = 1 is cyanine, the compound with n = 2 is carbocyanine, and the compound with n = 3 is dicarbocyanine. In equation (5), the compound with n = 4 is tricarbocyanine.

[0066] The organic groups R10 and R11 may be, for example, alkyl groups, aryl groups, aralkyl groups, and alkenyl groups. Alkyl groups may be, for example, methyl groups, ethyl groups, propyl groups, isopropyl groups, n-butyl groups, sec-butyl groups, isobutyl groups, tert-butyl groups, isopentyl groups, neopentyl groups, hexyl groups, cyclohexyl groups, octyl groups, nonyl groups, and decyl groups. Aryl groups may be, for example, phenyl groups, tolyl groups, xylyl groups, and naphthyl groups. Aralkyl groups may be, for example, benzyl groups, phenylethyl groups, phenylpropyl groups, and so on. Alkenyl groups may be, for example, vinyl groups, allyl groups, propenyl groups, isopropenyl groups, butenyl groups, hexenyl groups, cyclohexenyl groups, and octenyl groups.

[0067] Furthermore, at least some of the hydrogen atoms in each organic group may be substituted with halogen atoms or cyano groups. Halogen atoms may include fluorine, bromine, and chlorine. Substituted organic groups may include, for example, chloromethyl, chloropropyl, bromoethyl, trifluoropropyl, and cyanoethyl groups.

[0068] R12 or R13 may be, for example, a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, an isobutyl group, a tert-butyl group, an isopentyl group, a neopentyl group, a hexyl group, a cyclohexyl group, an octyl group, a nonyl group, and a decyl group.

[0069] The heterocycles containing each nitrogen atom may be, for example, pyrrole, imidazole, thiazole, and pyridine. The cations contained in these cyanine dyes may have structures represented by, for example, the following formulas (6) and (7).

[0070] [ka]

[0071] [ka]

[0072] Furthermore, the cations contained in the cyanine dye may have structures shown in formulas (8) to (47) below, for example. That is, each nitrogen atom contained in the cyanine dye may be contained within the cyclic structure shown below.

[0073] [ka]

[0074] [ka]

[0075] [ka]

[0076] [ka]

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[0110]

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[0112]

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[0113] Y in formula (4) - is, for example, tris(pentafluoroethyl) trifluorophosphate anion ([(C2F5)3PF3] - )(FAP). FAP has a structure represented by the following formula (48).

[0114]

Chem.

[0115] When an infrared cut filter is formed using the photosensitive coloring composition, the coating solution containing the photosensitive coloring composition is heated to about 200 °C, whereby an infrared cut filter, which is a cured film, is formed from the coating film. When the cyanine dye is heated to about 200 °C, the absorbance of the cyanine dye may change due to the change in the structure of the cyanine dye after heating from the structure of the cyanine dye before heating.

[0116] In this respect, FAP has a molecular weight and molecular structure that allows it to be located near the polymethine chains in the cyanine dye, thus suppressing the cleavage of the polymethine chains in the cyanine dye by heating. Therefore, the change in the infrared light absorbance of the cyanine dye due to heating is suppressed, and as a result, the change in the absorbance of the cured film formed from the photosensitive coloring composition is suppressed.

[0117] [Acrylic copolymer] As described above, the photosensitive coloring composition contains an acrylic copolymer. The acrylic copolymer contains a first repeating unit, a second repeating unit, and a third repeating unit. The first repeating unit is derived from a first acrylic monomer containing an epoxy group. As a result, the acrylic copolymer contains an epoxy group in its side chain. The second repeating unit is derived from a second acrylic monomer, which is acrylic acid (CH2HCOOH) or methacrylic acid (CH2C(CH3)COOH). The third repeating unit is derived from a third acrylic monomer containing an aromatic ring. As a result, the acrylic copolymer contains an aromatic ring in its side chain. In the acrylic copolymer, the sum of the first repeating unit, the second repeating unit, and the third repeating unit is 87.5% by weight or more, preferably 95% by weight, and more preferably 100% by weight.

[0118] The first repeating unit has the structure shown by the following formula (1).

[0119] [ka]

[0120] As described above, in the first repeating unit, R1 is a hydrogen atom or a methyl group, and R2 is a single bond, a linear alkylene group having 1 or more carbon atoms, a branched alkylene group having 3 or more carbon atoms, or an oxyalkylene group having 1 or more carbon atoms. R2 may be, for example, a methylene group, an ethylene group, a trimethylene group, a propylene group, or a butylene group. R3 is an epoxy group.

[0121] The first acrylic monomer may be, for example, glycidyl (meth)acrylate, 2-methylglycidyl (meth)acrylate, 3,4-epoxycyclohexylmethyl (meth)acrylate, or 4-hydroxybutyl (meth)acrylate glycidyl ether. From the viewpoint of the reactivity of the acrylic monomer, the first acrylic monomer is preferably glycidyl (meth)acrylate, 3,4-epoxycyclohexylmethyl (meth)acrylate, or 4-hydroxybutyl (meth)acrylate glycidyl ether, more preferably glycidyl (meth)acrylate, and particularly preferably glycidyl methacrylate. These acrylic monomers are also preferable because they are readily available.

[0122] The third repeating unit has the structure shown by the following formula (3).

[0123] [ka]

[0124] The third acrylic monomer may be, for example, benzyl (meth)acrylate, phenyl (meth)acrylate, phenethyl (meth)acrylate, phenoxyethyl (meth)acrylate, phenoxypolyethylene glycol (meth)acrylate, 2-hydroxy-3-phenoxypropyl (meth)acrylate, o-phenoxyphenylethyl (meth)acrylate, 2-naphthyl (meth)acrylate, or 9-anthrylmethyl (meth)acrylate. From the viewpoint of suppressing changes in the spectral properties of the dye, the third acrylic monomer is preferably benzyl (meth)acrylate, phenyl (meth)acrylate, phenethyl (meth)acrylate, more preferably phenyl (meth)acrylate, and particularly preferably phenyl methacrylate.

[0125] As described above, the acrylic copolymer satisfies the following conditions. (Condition 1) In the acrylic copolymer, the sum of the weights of the first repeating unit, the second repeating unit, and the third repeating unit is 87.5% by weight or more and 100% by weight.

[0126] (Condition 2) The first repeating unit is 10.0% by weight or more and 20.0% by weight or less. (Condition 3) The second repeating unit is 12.5% ​​by weight or more and 20.0% by weight or less. (Condition 4) The third repeating unit is 65% by weight or more.

[0127] The glass transition temperature of the acrylic copolymer is preferably 70°C or higher, and more preferably 100°C or higher. If the glass transition temperature is 70°C or higher, it is possible to increase the certainty of suppressing the deterioration of the spectral properties at wavelengths in which absorption is expected in the colorant contained in the cured film formed using the photosensitive coloring composition of this disclosure.

[0128] The average molecular weight of the acrylic copolymer is preferably 8,000 to 30,000, and more preferably 10,000 to 20,000. The average molecular weight of the acrylic copolymer is the weight-average molecular weight. The weight-average molecular weight of the acrylic copolymer can be measured, for example, by gel permeation chromatography.

[0129] Since the average molecular weight of the acrylic copolymer falls within the range of 8,000 to 30,000, when a cured film is formed using a photosensitive coloring composition, it is possible to further suppress the decrease in absorbance of the cured film at wavelengths in which absorption is expected from the coloring agent contained in the cured film.

[0130] Furthermore, since the average molecular weight of the acrylic copolymer falls within the range of 30,000 or less, patterning of coating films using photosensitive colored compositions is easy. In particular, when forming rectangular holes as a hole pattern in the coating film, the alkaline developer does not circulate easily in the hole pattern, so the development process takes time. Even in this case, since the molecular weight of the acrylic copolymer falls within the range of 30,000 or less, the decrease in the accuracy of the rectangularity of the hole pattern is suppressed. The rectangularity of the hole pattern means that, in the cross-section in the thickness direction of the cured film, the angle formed between the surface of the cured film and the side surface that determines the hole pattern is rectangular. The closer the angle formed between the surface of the cured film and the side surface that determines the hole pattern is to a right angle, the higher the rectangularity of the hole pattern.

[0131] The acid value of the acrylic copolymer is preferably within the range of 80 KOH mg / g to 130 KOH mg / g. An acid value of 80 KOH mg / g or higher suppresses the decrease in solubility of the photosensitive colored composition in alkaline developer. This reduces the time required for the development process, and consequently, prevents a decrease in the productivity of infrared light cut filters using the photosensitive colored composition. Furthermore, an acid value of 130 KOH mg / g or lower suppresses a decrease in the infrared light absorption capacity of the infrared light cut filter. In this disclosure, the acid value of the acrylic copolymer is measured as the amount (mg) of potassium hydroxide (KOH) required to neutralize 1 g of the acrylic copolymer. The oxidation of the acrylic copolymer can be determined by titration using a potassium hydroxide solution.

[0132] In addition to the first, second, and third acrylic monomers described above, other monomers may be used in the production of acrylic copolymers. Monomers other than the first, second, and third acrylic monomers may be, for example, alkyl (meth)acrylate compounds, aromatic alkenyl compounds, vinyl cyanide compounds, acrylamide compounds, and maleimide compounds.

[0133] Alkyl (meth)acrylate compounds may include, for example, methyl (meth)acrylate, ethyl (meth)acrylate, n-butyl (meth)acrylate, iso-butyl (meth)acrylate, tert-butyl (meth)acrylate, n-hexyl (meth)acrylate, n-octyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, decyl (meth)acrylate, dodecyl (meth)acrylate, stearyl (meth)acrylate, etc. Aromatic alkenyl compounds may include, for example, styrene, α-methylstyrene, p-methylstyrene, p-methoxystyrene, etc. Vinyl cyanide compounds may include, for example, acrylonitrile, methacrylonitrile, etc. Acrylamide compounds may include, for example, acrylamide, methacrylamide, etc. Maleimide compounds may include, for example, N-cyclohexylmaleimide, N-phenylmaleimide, etc.

[0134] [Photopolymerization initiator] The photopolymerization initiator may be, for example, an acetophenone-based photopolymerization initiator, a benzoin-based photopolymerization initiator, a thioxanthone-based photopolymerization initiator, a triazine-based photopolymerization initiator, a borate-based photopolymerization initiator, a carbazole-based photopolymerization initiator, an imidazole-based photopolymerization initiator, or an oxime ester-based polymerization initiator.

[0135] Acetophenone-based photopolymerization may involve, for example, 4-phenoxydichloroacetophenone, 4-t-butyl-dichloroacetophenone, diethoxyacetophenone, 1-(4-isopropylphenyl)-2-hydroxy-2-methylpropan-1-one, 1-hydroxycyclohexylphenyl ketone, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butan-1-one, and 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one.

[0136] Benzoin-based photopolymerization initiators may include, for example, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, and benzyl dimethyl ketal.

[0137] Thioxanthone-based photopolymerization initiators may include, for example, benzophenone, benzoylbenzoic acid, methyl benzoylbenzoate, 4-phenylbenzophenone, hydroxybenzophenone, acrylic benzophenone, and 4-benzoyl-4'-methyldiphenyl sulfide.

[0138] Thioxanthone-based photopolymerization initiators may include, for example, thioxanthone, 2-chlorthioxanthone, 2-methylthioxanthone, isopropylthioxanthone, and 2,4-diisopropylthioxanthone.

[0139] Examples of triazine-based photopolymerization initiators include 2,4,6-trichloro-s-triazine, 2-phenyl-4,6-bis(trichloromethyl)-s-triazine, 2-(p-methoxyphenyl-4,6-bis(trichloromethyl)-s-triazine, 2-(p-tolyl)-4,6-bis(trichloromethyl)-s-triazine, 2-piperonyl-4,6-bis(trichloromethyl)-s-triazine, and 2,4-bis(trichloromethyl)-6-styryl-chloromethyl These may be methyl(4'-methoxystyryl)-s-triazine, 2,4-bis(trichloromethyl)-6-styryl-s-triazine, 2-(naphtho-1-yl)-4,6-bis(trichloromethyl)-s-triazine, 2-(4-methoxynaphtho-1-yl)-4,6-bis(trichloromethyl)-s-triazine, 2,4-trichloromethyl(piperonyl)-6-triazine, and 2,4-trichloromethyl(4'-methoxystyryl)-6-triazine, etc.

[0140] Oxime ester-based photopolymerization initiators may include, for example, 3-benzoyloxyiminobutan-2-one, 3-acetoxyiminobutan-2-one, 3-propionyloxyiminobutan-2-one, 2-acetoxyiminopentan-3-one, 2-acetoxyimino-1-phenylpropan-1-one, 2-benzoyloxyimino-1-phenylpropan-1-one, 3-(4-toluenesulfonyloxy)iminobutan-2-one, and 2-ethoxycarbonyloxyimino-1-phenylpropan-1-one.

[0141] The oxime ester-based photopolymerization initiator may also be, for example, IRGACURE OXE01 (manufactured by BASF), IRGACURE OXE02 (manufactured by BASF) (IRGACURE is a registered trademark), TR-PBG-304 (manufactured by Changzhou Strong Electronic New Materials Co., Ltd.), or ADEKA Arclus NCI-930 (manufactured by ADEKA Corporation) (ADEKA Arclus is a registered trademark). One or more of the above-mentioned photopolymerization initiators can be used as the photopolymerization initiator.

[0142] [Photopolymerizable monomers] The photopolymerizable monomer may be, for example, an acrylic monomer having three or more functional groups. Examples of acrylic monomers having three or more functional groups include pentaerythritol triacrylate, pentaerythritol tetraacrylate, trimethylolpropane triacrylate, trimethylolpropane PO (propylene oxide) modified (n=1) triacrylate, trimethylolpropane PO modified (n=2) triacrylate, trimethylolpropane EO (ethylene oxide) modified (n=1) triacrylate, trimethylolpropane EO modified (n=2) triacrylate, dipentaerythritol pentaacrylate, dipentaerythritol hexaacrylate, pentaerythritol tetraacrylate, ditrimethylolpropane tetraacrylate, isocyanuric acid EO modified diacrylate, isocyanuric acid EO modified triacrylate, isocyanuric acid EO modified citriaacrylate, and the like.

[0143] The acrylic monomer having three or more functional groups is preferably a trifunctional acrylic monomer, an EO-modified trifunctional acrylic monomer, or a PO-modified trifunctional acrylic monomer. EO or PO modification imparts hydrophilicity, thereby improving the developability of the cured film formed using the photosensitive colored resin composition.

[0144] Furthermore, the photopolymerizable monomer may also be a (meth)acrylate containing an amino group and having two or more functional groups. Since a photopolymerizable monomer containing an amino group can capture oxygen that inhibits the photopolymerization reaction, the presence of an amino group in the photopolymerizable monomer can suppress the inhibition of the polymerization reaction caused by oxygen. Moreover, since a photopolymerizable monomer containing an amino group has two or more functional groups, the rate of the polymerization reaction is increased, making it possible to further suppress the inhibition of the polymerization reaction. As a result, the coating film hardens more easily when exposed to light, and the precision of the pattern shape in the coating film is improved.

[0145] The (meth)acrylates containing amino groups and having two or more functionalities may include, for example, EBECRYL80 (manufactured by Daicel Ornex), EBECRYL7100 (manufactured by Daicel Ornex), CN371 NS (manufactured by Arkema), CN550 (manufactured by Arkema), CN551 (manufactured by Arkema), Laromer 83F (manufactured by BASA), Laromer 84F (manufactured by BASA), and the like. The photosensitive colored composition may contain two or more of the above-mentioned photopolymerizable monomers.

[0146] [solvent] The photosensitive colored composition contains a solvent. Depending on the solvent, it is possible to adjust the viscosity of the photosensitive colored composition, which contains a colorant and an acrylic copolymer. This makes it easier to apply the coating solution containing the photosensitive colored composition when forming a cured film using the photosensitive colored composition.

[0147] The solvent is preferably compatible with the colorant and copolymer, has high volatility to the extent that it can volatilize during the curing film formation process, and does not cause unevenness in the cured film when the solvent volatilizes. The solvent may be an ester solvent, alcohol ether solvent, ketone solvent, aromatic solvent, amide solvent, or alcohol solvent.

[0148] Ester solvents may include, for example, methyl acetate, ethyl acetate, n-butyl acetate, isobutyl acetate, t-butyl acetate, methyl lactate, ethyl lactate, and propylene glycol monomethyl ether acetate. Alcohol ether solvents may include, for example, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, 3-methoxy-1-butanol, and 3-methoxy-3-methyl-1-butanol. Ketone solvents may include, for example, acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone. Aromatic solvents may include, for example, benzene, toluene, and xylene. Amide solvents may include, for example, formamide and dimethylformamide. The alcoholic solvent may be, for example, methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, s-butanol, t-butanol, diacetone alcohol, and 2-methyl-2-butanol.

[0149] [Additives] The photosensitive coloring composition may optionally contain additives. These additives may be, for example, at least one of polymerization inhibitors, surfactants, and storage stabilizers.

[0150] The polymerization inhibitor may be, for example, a quinone-based polymerization inhibitor, a hindered phenol-based polymerization inhibitor, a nitrosamine-based polymerization inhibitor, or a phenothiazine-based polymerization inhibitor. The photosensitive colored composition may contain two or more polymerization inhibitors.

[0151] The surfactant may be, for example, anionic surfactant, nonionic surfactant, cationic surfactant, amphoteric surfactant, or silicone-based surfactant. The anionic surfactant may be sodium lauryl sulfate, polyoxyethylene alkyl ether sulfate, sodium dodecylbenzenesulfonate, alkali salt of styrene-acrylic acid copolymer, sodium stearate, sodium alkylnaphthalenesulfonate, sodium alkyldiphenyl ether disulfonate, monoethanolamine lauryl sulfate, triethanolamine lauryl sulfate, ammonium lauryl sulfate, monoethanolamine stearate, sodium stearate, sodium lauryl sulfate, monoethanolamine of styrene-acrylic acid copolymer, and polyoxyethylene alkyl ether phosphate ester.

[0152] Nonionic surfactants may include, for example, polyoxyethylene oleyl ether, polyoxyethylene lauryl ether, polyoxyethylene nonylphenyl ether, polyoxyethylene alkyl ether phosphate ester, polyoxyethylene sorbitan monostearate, and polyethylene glycol monolaurate.

[0153] Cationic surfactants may include, for example, alkyl quaternary ammonium salts and their ethylene oxide adducts. Amphoteric surfactants may include alkyl betaines such as alkyldimethylaminoacetic acid betaine and alkylimidazolines. The photosensitive coloring composition may contain two or more surfactants.

[0154] Storage stabilizers may include benzyltrimethyl chloride, quaternary ammonium chloride, organic acids, methyl ethers of organic acids, t-butylpyrocatechol, organophosphines, phosphates, etc. Quaternary ammonium chloride may be, for example, diethylhydroxyamine. Organic acids may be, for example, lactic acid and oxalic acid. Organophosphines may be, for example, triethylphosphine and triphenylphosphine.

[0155] [Composition of photosensitive colored composition] The photosensitive colored composition preferably satisfies conditions 5 and 6. (Condition 5) The ratio of the weight of the photopolymerizable monomer to the weight of the acrylic copolymer is 0.4 or more and 0.7 or less. (Condition 6) The ratio of the weight of the photopolymerization initiator to the weight of the photopolymerizable monomer is 0.03 or more and 0.08 or less.

[0156] The lower limit of the ratio of the weight of the photopolymerizable monomer to the weight of the acrylic copolymer is preferably 0.45, and more preferably 0.5. The upper limit of the ratio of the weight of the photopolymerizable monomer to the weight of the acrylic copolymer is preferably 0.65, and more preferably 0.6.

[0157] By having a weight ratio of photopolymerizable monomer to acrylic copolymer within the range of 0.4 to 0.7, it is possible to improve the precision of the pattern shape. Specifically, when the weight ratio is 0.4 or higher, it is possible to increase the development speed to a degree that allows for the formation of fine patterns. Furthermore, when the weight ratio is 0.7 or lower, it is possible to suppress the increase in transmittance at wavelengths where absorption is expected in the cured film formed using the colored photosensitive composition.

[0158] The lower limit of the ratio of the weight of the photopolymerization initiator to the weight of the photopolymerizable monomer is preferably 0.03. The upper limit of the ratio of the weight of the photopolymerization initiator to the weight of the photopolymerizable monomer is preferably 0.06.

[0159] By having a weight ratio of photopolymerization initiator to photopolymerizable monomer within the range of 0.03 to 0.08, it is possible to improve the accuracy of the pattern shape. When this weight ratio is 0.03 or higher, the adhesion between the cured film formed using the photosensitive coloring composition and the substrate is improved, so that even when forming fine patterns, peeling of the cured film during the development process is suppressed. Furthermore, when this weight ratio is 0.08 or lower, an increase in transmittance at wavelengths where absorption is expected in the cured film formed using the colored photosensitive composition is suppressed.

[0160] In a photosensitive colored composition, the percentage of the weight of the colorant (WC) relative to the weight of the solvent (WS) (WC / WS × 100) is preferably 0.6% by weight or more and 30% by weight or less. As mentioned above, infrared light cut filters used in solid-state image sensors are required to have a thickness of several hundred nanometers or more and several micrometers or less. In order to achieve the desired absorbance with a thin infrared light cut filter, it is necessary that a predetermined amount or more of the colorant is dissolved in the solvent in the photosensitive colored composition for forming the infrared light cut filter.

[0161] In this regard, by having a colorant weight percentage of 0.6% or more, the thin-film infrared light cut filter can have sufficient absorbance as an infrared light cut filter. Furthermore, by having a colorant weight percentage of 30% or less, even if the solvent evaporates during the formation of the infrared light cut filter, the deposition of the colorant on the surface of the infrared light cut filter is suppressed.

[0162] Furthermore, because the coloring agent is dissolved in the solvent, precipitation of the coloring agent is suppressed when the infrared light cut filter is formed, thereby preventing a decrease in the transparency of the infrared light cut filter. In addition, the occurrence of irregularities on the surface of the infrared light cut filter caused by precipitates containing the coloring agent is suppressed, thereby preventing variations in the thickness of the infrared light cut filter.

[0163] In a photosensitive colored composition, the content of acrylic copolymer in the total solids of the photosensitive colored composition is preferably 30% by weight or more and 70% by weight or less. The lower limit of the acrylic copolymer content is more preferably 40% by weight. The upper limit of the acrylic copolymer content is more preferably 65% ​​by weight.

[0164] [Infrared light cut filter] The infrared light cut filter contains a colorant, an acrylic copolymer, and an acrylic polymer. The infrared light cut filter is a cured film obtained by curing a photosensitive colored composition. The colorant has an absorption maximum in the wavelength band between 700 nm and 1100 nm.

[0165] The acrylic copolymer contains the first repeating unit, the second repeating unit, and the third repeating unit described above. In the acrylic copolymer, the total weight of the acrylic copolymer is 100% by weight, the weight of the first repeating unit is 10% by weight or more and 20% by weight or less, the weight of the second repeating unit is 12.5% ​​by weight or more and 20% by weight or less, and the weight of the third repeating unit is 65% by weight or more.

[0166] In the acrylic copolymer, it is preferable that the sum of the weights of the first repeating unit, the second repeating unit, and the third repeating unit is 100% by weight. A polymer different from an acrylic copolymer is a polymer formed by polymerizing photopolymerizable monomers contained in a photosensitive resin composition. The polymer is preferably an acrylic polymer. The acrylic polymer may be, for example, a trifunctional acrylic monomer, an EO-modified trifunctional acrylic monomer, a PO-modified trifunctional acrylic monomer, or a homopolymer of a bifunctional or more (meth)acrylate containing an amino group. Alternatively, the acrylic polymer may be an acrylic copolymer formed from two or more acrylic monomers, such as a trifunctional acrylic monomer, an EO-modified trifunctional acrylic monomer, a PO-modified trifunctional acrylic monomer, and a bifunctional or more (meth)acrylate containing an amino group.

[0167] [Method for manufacturing acrylic copolymer] An acrylic copolymer can be obtained by polymerizing the first acrylic monomer, the second acrylic monomer, and the third acrylic monomer using a monomer mixture containing at least the first acrylic monomer, the second acrylic monomer, and the third acrylic monomer as described above. For example, radical polymerization can be used as a polymerization method for the acrylic monomers. Radical polymerization includes solution polymerization, suspension polymerization, and emulsion polymerization. Of these, it is preferable to polymerize the first acrylic monomer, the second acrylic monomer, and the third acrylic monomer using solution polymerization. Solution polymerization makes it easy to adjust the weight-average molecular weight of the copolymer.

[0168] Polymerization solvents that can be used in solution polymerization are solvents capable of dissolving acrylic monomers and polymerization initiators. Examples of polymerization solvents include methanol, ethanol, 1-propanol, acetone, methyl ethyl ketone, and propylene glycol monomethyl ether.

[0169] The percentage of the total weight of acrylic monomer (WM) relative to the weight of polymerization solvent (WS) (WM / WS × 100) is preferably 10% by weight or more and 60% by weight or less, and more preferably 20% by weight or more and 50% by weight or less. A percentage of 20% by weight or more suppresses the residue of monomers and prevents a decrease in the molecular weight of the resulting acrylic copolymer. Furthermore, a percentage of 60% by weight or less makes it easier to control the exothermic reaction of the solution.

[0170] In addition to controlling the concentration of acrylic monomers in the polymerization solution, it is also possible to control the molecular weight of the acrylic copolymer by adjusting the concentration of the radical polymerization initiator in the polymerization solution.

[0171] Polymerization initiators may include, for example, organic peroxides and azo polymerization initiators. Organic peroxides may include, for example, di(4-t-butylcyclohexyl)peroxydicarbonate and 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate. Azo polymerization initiators may include, for example, 2,2'-azobisisobutyronitrile. In the polymerization reaction, only one of the exemplified polymerization initiators may be used, or two or more may be used. The amount of polymerization initiator used can be appropriately set depending on the combination of monomers to be polymerized and the conditions of the polymerization reaction.

[0172] When adding monomers to the polymerization solvent, for example, the entire amount of monomer may be added to the polymerization solvent at once. Alternatively, a portion of the monomer may be added to the polymerization solvent, and the remaining monomer may be added dropwise. Alternatively, the monomer may be added to the polymerization solvent by adding the entire amount of monomer dropwise. When adding monomers to the polymerization solvent, it is preferable to add at least a portion of the total amount of monomer dropwise. This makes it easier to control the exothermic reaction in the polymerization compared to adding the entire amount of monomer to the polymerization solvent at once.

[0173] When adding the polymerization initiator to the polymerization solvent, for example, the entire amount of polymerization initiator may be added to the polymerization solvent at once. Alternatively, a portion of the polymerization initiator may be added to the polymerization solvent, and the remaining polymerization initiator may be added dropwise. Alternatively, the entire amount of polymerization initiator may be added dropwise. It is preferable to add the polymerization initiator and monomer dropwise to the polymerization solvent. In this case, the polymerization reaction can be easily controlled. It is also preferable to add the polymerization initiator dropwise after the addition of monomer to the polymerization solvent has been completed. This makes it possible to reduce the amount of residual monomer. In this case, the period of adding monomer to the polymerization solvent and the period of adding polymerization initiator to the polymerization solvent do not have to overlap, or at least a portion of the period of adding monomer to the polymerization solvent may overlap with the period of adding polymerization initiator to the polymerization solvent.

[0174] The optimal range of polymerization temperature depends on the type of polymerization solvent, etc. The polymerization temperature may be, for example, a temperature within the range of 50°C to 110°C. The optimal range of polymerization time depends on the type of polymerization initiator and the polymerization temperature, etc. For example, when 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate is used as the polymerization initiator and the polymerization temperature is set to 95°C, the polymerization time is preferably about 6 hours.

[0175] Furthermore, the reaction solution containing the acrylic copolymer obtained by the polymerization reaction may be used in the production of a photosensitive colored composition without any further processing other than the polymerization reaction. Alternatively, the acrylic copolymer may be isolated from the reaction solution after the polymerization reaction. For isolation of the acrylic copolymer, methods such as filtration and purification can be used.

[0176] In the reaction solution after polymerization, the percentage of the weight of acrylic monomers (WM) to the sum of the weight of the acrylic copolymer and the weight of the acrylic monomers used to constitute the acrylic copolymer (W(M+P)) (WM / W(M+P) × 100) is preferably 20% or less. The acrylic monomers contained in the reaction solution after polymerization are residual monomers that were not used in the production of the acrylic copolymer. Compared to the case where the residual monomer content is greater than 20%, the absorbance of the cured film is less likely to change when a cured film is formed using a photosensitive colored composition.

[0177] Furthermore, the percentage of the weight of the acrylic monomer (WM) to the sum of the weights of the acrylic copolymer and the acrylic monomer (W(M+P)) (WM / W(M+P)×100) is more preferably 10% or less, and even more preferably 3% or less. The weight of the acrylic copolymer and the weight of the acrylic monomer can be quantified based on the analysis results of the reaction solution containing the acrylic copolymer. The analysis method of the reaction solution may be, for example, gas chromatography-mass spectroscopy (GC-MS), nuclear magnetic resonance spectroscopy (NMR), and infrared spectroscopy (IR).

[0178] Methods for changing the ratio of the weight of acrylic monomer (WM) to the sum of the weights of acrylic copolymer and acrylic monomer (W(M+P)) may include, for example, changing the polymerization time and changing the polymerization temperature. Alternatively, methods for changing the ratio of the weight of acrylic monomer (WM) to the sum of the weights of acrylic copolymer and acrylic monomer (W(M+P)) may include changing the concentrations of acrylic monomer and polymerization initiator at the start of the polymerization reaction. Methods for changing the ratio of the weight of acrylic monomer (WM) to the sum of the weights of acrylic copolymer and acrylic monomer (W(M+P)) may include changing the purification conditions after the polymerization reaction. Of these, changing the polymerization time is preferred because it provides high precision in controlling the ratio of the weight of residual monomer.

[0179] [Method for producing a photosensitive colored composition] A method for producing a photosensitive colored composition includes mixing a colorant, a photopolymerization initiator, a photopolymerizable monomer, and an acrylic copolymer. For example, a photosensitive colored composition can be produced by mixing the above-mentioned colorant, photopolymerization initiator, photopolymerizable monomer, acrylic copolymer, and solvent using a mixing apparatus. The method for producing a photosensitive colored composition may also include a step of filtering the mixture after the step of mixing the colorant, acrylic copolymer, photopolymerization initiator, photopolymerizable monomer, and solvent to produce a mixture. Filtering the mixture makes it possible to remove foreign matter and insoluble matter from the photosensitive colored composition. A filter can be used to filter the mixture.

[0180] [Manufacturing method for infrared light cut filters] A method for manufacturing an infrared light cut filter includes applying a photosensitive colored composition to a substrate to form a coating film, exposing the coating film by irradiating a part of the coating film with light, developing the coating film after exposure, and curing the coating film by heating the coating film after development.

[0181] The substrate may be, for example, a transparent resin plate, a transparent film, a transparent glass plate, a silicon wafer, or an image sensor. For coating the photosensitive colored composition, for example, a spin coater, a bar coater, a roll coater, a gravure coater, an offset coater, or a spray can be used.

[0182] The solvent is removed from the photosensitive coloring composition by heating the coating film formed by applying the photosensitive coloring composition. A hot plate and an oven can be used to heat the coating film. Next, the coating film is exposed by irradiating a portion of it with light using an exposure mask. Subsequently, an infrared light cut filter having a predetermined pattern can be obtained by developing the exposed coating film with a developer solution.

[0183] As mentioned above, it is preferable to use a photosensitive colored composition in which the percentage of the weight of the colorant relative to the weight of the solvent is 0.6% by weight or more and 30% by weight or less when manufacturing infrared light cut filters. Furthermore, when manufacturing infrared light cut filters, the molar extinction coefficient ε at the wavelength having an absorption maximum is 3.0 × 10⁻⁶. 4 It is preferable to use a photosensitive coloring composition containing the above-mentioned coloring agent.

[0184] Furthermore, it is preferable that the dissolution rate of the coating film in the alkaline developer at 23°C, i.e., the dissolution rate of the photosensitive coloring composition, be 20 nm / second or higher. A dissolution rate of 20 nm / second or higher makes it possible to improve the accuracy of the pattern shape, even when forming fine patterns. In particular, when forming unexposed areas with a rectangular shape as viewed from a viewpoint opposite the plane on which the coating film spreads, and thereby forming a hole pattern, the alkaline developer does not circulate easily in the hole pattern. Therefore, if the dissolution rate is less than 20 nm / second, it takes time to develop the coating film, which reduces the accuracy of the hole pattern shape, i.e., the rectangularity of the hole pattern decreases. Also, because it takes time to develop the coating film, the productivity of infrared light cut filters decreases. Even in this case, a dissolution rate of 20 nm / second or higher suppresses the decrease in the rectangularity of the hole pattern and the decrease in the productivity of infrared light cut filters.

[0185] The developer may be an alkaline developer. The alkaline developer may be, for example, an inorganic alkaline developer or an organic alkaline developer. An inorganic alkaline developer may be, for example, an aqueous solution of sodium hydroxide, an aqueous solution of potassium hydroxide, or an aqueous solution of sodium carbonate. An organic alkaline developer may be, for example, an aqueous solution of tetrahydroxyammonium. The developer may also contain a surfactant. This improves the wettability of the developer to the coating film.

[0186] The dissolution rate of the coating film can be measured by the following method. First, a photosensitive coloring composition is applied to a silicon wafer to form a coating film. Next, the coating film is pre-baked at 90°C for 2 minutes to form a pre-baked film with a thickness of 5.0 μm ± 0.25 μm. Subsequently, the pre-baked film is immersed in an alkaline developer for 30 seconds. At this time, the temperature of the alkaline developer is set to 23 ± 1°C. Then, the thickness of the pre-baked film after immersion is measured. The dissolution rate can be calculated using the following formula. Dissolution rate = (thickness before immersion - thickness after immersion) / immersion time For measuring the dissolution rate, for example, a dissolution rate monitor can be used.

[0187] [Manufacturing example] Referring to Figure 2, an example of acrylic copolymer production will be explained. Note that the weight ratio of repeating units derived from each monomer in the resulting copolymer is equal to the weight ratio of each monomer at the time of copolymer production.

[0188] [Manufacturing Example 1] A 1 L separable flask equipped with a stirrer, thermometer, condenser, dropping funnel, and nitrogen inlet tube was filled with 200.0 g of propylene glycol monomethyl ether acetate, and then the flask was purged with nitrogen to create a nitrogen atmosphere. A monomer solution was prepared by mixing 24.0 g of glycidyl methacrylate, 24.0 g of methacrylic acid, and 112.0 g of phenyl methacrylate, and a polymerization initiator solution was prepared by mixing 40.0 g of propylene glycol monomethyl ether acetate and 24.0 g of 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate (manufactured by NOF Corporation, Perocta O) (Perocta is a registered trademark).

[0189] The flask was heated to 95°C, and then the monomer solution and the polymerization initiator solution were simultaneously added dropwise to the flask over 3 hours. The mixture of the monomer solution and the polymerization initiator solution was then reacted at 95°C for 2 hours, after which 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate (0.6 g), the polymerization initiator, was added to the mixture. The mixture with the added polymerization initiator was further reacted at 95°C for 3 hours, and then the mixture was diluted with propylene glycol monomethyl ether acetate to obtain a 20% by weight polymer solution. The weight-average molecular weight of the acrylic copolymer contained in the polymer solution was found to be 8,000.

[0190] [Manufacturing Example 2] In Production Example 1, the monomer solution was changed to a mixed solution of glycidyl methacrylate (16.0 g), methacrylic acid (20.0 g), and phenyl methacrylate (124.0 g). The 20% by weight polymer solution of Production Example 2 was obtained in the same manner as in Production Example 1. The weight-average molecular weight of the acrylic copolymer contained in the polymer solution was found to be 8,000.

[0191] [Manufacturing Example 3] In Production Example 1, the monomer solution was changed to a mixed solution of glycidyl methacrylate (24.0 g), methacrylic acid (32.0 g), and phenyl methacrylate (104.0 g). The 20% by weight polymer solution of Production Example 3 was obtained in the same manner as in Production Example 1. The weight-average molecular weight of the acrylic copolymer contained in the polymer solution was found to be 8,000.

[0192] [Manufacturing Example 4] In Production Example 1, the monomer solution was changed to a mixed solution of glycidyl methacrylate (32.0 g), methacrylic acid (20.0 g), and phenyl methacrylate (108.0 g). The 20% by weight polymer solution of Production Example 4 was obtained in the same manner as in Production Example 1. The weight-average molecular weight of the acrylic copolymer contained in the polymer solution was found to be 8,000.

[0193] [Manufacturing Example 5] In Production Example 1, a 20% by weight polymer solution of Production Example 5 was obtained by the same method as in Production Example 1, except that the weight of 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate was changed to 9.6 g. The weight-average molecular weight of the acrylic copolymer contained in the polymer solution was found to be 20,000.

[0194] [Manufacturing Example 6] In Production Example 1, the weight of 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate was changed to 40.0 g, but otherwise the 20% by weight polymer solution of Production Example 6 was obtained by the same method as in Production Example 1. The weight-average molecular weight of the acrylic copolymer contained in the polymer solution was found to be 5,000.

[0195] [Production Example 7] In Production Example 1, a 20% by weight polymer solution of Production Example 7 was obtained in the same manner as in Production Example 1, except that the weight of 1,1,3,3-tetramethylbutyl peroxy-2-ethylhexanoate in Production Example 1 was changed to 4.8 g. It was confirmed that the weight average molecular weight of the acrylic copolymer contained in the polymer solution was 35,000.

[0196] [Production Example 8] In Production Example 1, a 20% by weight polymer solution of Production Example 8 was obtained in the same manner as in Production Example 1, except that the monomer solution was changed to a mixed solution of glycidyl methacrylate (36.0 g), methacrylic acid (12.0 g), and phenyl methacrylate (112.0 g). It was confirmed that the weight average molecular weight of the acrylic copolymer contained in the polymer solution was 8,000.

[0197] [Production Example 9] In Production Example 1, a 20% by weight polymer solution of Production Example 9 was obtained in the same manner as in Production Example 1, except that the monomer solution was changed to a mixed solution of glycidyl methacrylate (12.0 g), methacrylic acid (20.0 g), and phenyl methacrylate (128.0 g). It was confirmed that the weight average molecular weight of the acrylic copolymer contained in the polymer solution was 8,000.

[0198] [Production Example 10] In Production Example 1, a 20% by weight polymer solution of Production Example 10 was obtained in the same manner as in Production Example 1, except that the monomer solution was changed to a mixed solution of glycidyl methacrylate (24.0 g), methacrylic acid (40.0 g), and phenyl methacrylate (96.0 g). It was confirmed that the weight average molecular weight of the acrylic copolymer contained in the polymer solution was 8,000.

[0199] [Weight Average Molecular Weight] The weight average molecular weight of the acrylic copolymer contained in the polymer solution of each production example was determined by the following method.

[0200] For the 20% by weight polymer solutions of each production example, the weight average molecular weight (Mw) was determined using gel permeation chromatography (GPC). The conditions for determining the weight average molecular weight were set as follows.

[0201] Apparatus: HLC-8220, manufactured by Tosoh Corporation Column: LF-804, manufactured by Shodex Standard substance: Polystyrene Eluent: THF (tetrahydrofuran) Flow rate: 1.0 ml / min Column temperature: 40 °C Detector: RI (differential refractive index detector)

[0202] [Examples] [Preparation of photosensitive coloring composition] As shown in Figure 3, using the copolymers of Production Examples 1 to 10, photosensitive coloring compositions of Examples 1 to 18 and Comparative Examples 1 to 3 were prepared. At this time, the materials described below were used. In Figure 3, the first ratio is the ratio of the weight of the photopolymerizable monomer to the weight of the acrylic copolymer, and the second ratio is the ratio of the weight of the photoinitiator to the weight of the photopolymerizable monomer.

[0203] (a) Colorant (b) Acrylic copolymer (c) Photopolymerizable monomer: TMPTA-based acrylate (Aronix M-350, manufactured by Toagosei Co., Ltd.) (Aronix is a registered trademark) (d) Photoinitiator: Oxime ester-based polymerization initiator (Irgacure OXE02, manufactured by BASF) (Irgacure is a registered trademark) (e) Solvent: Propylene glycol monomethyl ether acetate (PGMAC)

[0204] For each of Examples 1 to 18 and Comparative Examples 1 to 3, materials (a) to (d) described above were prepared in the mixing ratios shown in Figure 3. Next, a mixed solution was prepared by mixing all the materials, and the mixture was stirred for 1 hour until the solution was homogenized. Subsequently, the mixed solution was filtered using a 0.45 μm filter. This yielded the photosensitive colored compositions for each example and comparative example.

[0205] In this case, the photosensitive colored compositions of Examples 1 to 7, Examples 11 to 18, and Comparative Examples 1 to 3 used a cyanine dye represented by formula (6) above as the colorant. In Example 8, a cyanine dye represented by formula (33) above was used as the colorant. In Example 9, a phthalocyanine dye (FDN-003, manufactured by Yamada Chemical Industries, Ltd.) was used as the colorant. In Example 10, a diimonium dye (Dye1451, manufactured by ORGANICA) was used as the colorant.

[0206] [Method for evaluating spectral properties] The spectral properties of the cured films obtained from the photosensitive colored compositions of each example and comparative example were evaluated using the following method.

[0207] To prepare evaluation substrates for evaluating spectral characteristics, a coating film was first formed by applying the photosensitive colored composition of each example and comparative example onto a transparent substrate. Next, after drying the coating film, exposure was performed using an exposure unit (FPA-5510iZ, manufactured by Canon Inc.) with an exposure dose of 8000 J / cm². 2 The exposure was performed using the specified settings. Subsequently, the coating film was cured by heating it at 230°C for 3 minutes. This resulted in cured films with a thickness of 1.5 μm for each example and comparative example of the photosensitive colored composition.

[0208] To evaluate the spectral characteristics, a spectrophotometer (U-4100, manufactured by Hitachi High-Technologies Corporation) was used to measure the transmittance of the cured films of each example and comparative example for light with wavelengths ranging from 350 nm to 1150 nm. This yielded transmittance spectra for each cured film. The lowest transmittance spectrum for each cured film was observed within the range of 700 nm to 1100 nm. Cured films with a lowest transmittance of 25% or less within this range possess desirable infrared light absorption capabilities for application in infrared light cut-off filters of solid-state image sensors.

[0209] [Method for evaluating rectangularness] The rectangularity of the cured films obtained from the photosensitive colored compositions of each example and comparative example was evaluated by the following method.

[0210] To evaluate the rectangularity, a planarization layer was first formed on the silicon wafer. Next, the photosensitive colored compositions of each example and comparative example were applied to the planarization layer using a spin coater to form a coating film. The rotation speed of the spin coater was set to 1000 rpm. Then, the coating film was pre-baked using a hot plate. During this process, the coating film was heated at 90°C for 2 minutes.

[0211] Subsequently, the coating film was exposed using an exposure mask equipped with multiple translucent areas having a 2.0 μm square shape. This was done using an exposure machine (FPA-5510iZ, manufactured by Canon Inc.) with an exposure dose of 2000 J / cm². 2 The settings were adjusted as follows. Next, the exposed coating was developed using an alkaline developer (OD-260C, manufactured by ADEKA Corporation), and then the developed coating was washed with water and dried. This resulted in a coating with multiple 2.0 μm square hole patterns. Next, the coating with the hole pattern was cured by heating the silicon wafer using a hot plate. The silicon wafer was heated at 230°C for 3 minutes. This resulted in a cured film with a thickness of 1.5 μm.

[0212] The cured film was cut along its thickness to create an evaluation cross-section. Next, the rectangularity of the hole pattern was evaluated by observing the evaluation cross-section at 30,000x magnification using a scanning electron microscope (S-4800, Hitachi High-Technologies Corporation). In this process, the rectangularity of the hole pattern was judged to be good if the angle formed by the surface of the cured film and the side surface that determines the hole pattern was within the range of 75° to less than 95°.

[0213] [Method for evaluating dissolution rate] The photosensitive colored compositions of each example and comparative example were applied onto a silicon wafer using a spin coater to form a coating film. The rotation speed of the silicon wafer was set to a speed that resulted in a film thickness of 5.0 ± 0.25 μm after heating. Next, a cured film was obtained by heating the silicon wafer using a hot plate. The coating film was pre-baked by heating the silicon wafer at 90°C for 2 minutes. Then, the pre-baked coating film was developed for 30 seconds using an alkaline developer (OD-260C, manufactured by ADEKA Corporation) set at 23 ± 1°C. The dissolution rate of the coating film was calculated by subtracting the thickness of the coating film after development from the thickness of the coating film before development, and dividing the result by the development time.

[0214] [Evaluation Results] The evaluation results for transmittance, rectangularity, and dissolution rate are shown in Figure 4. As shown in FIG. 4, the dissolution rate of the photosensitive coloring composition was 40 nm / sec in Examples 1, 5, 6, 8 to 10, 17, and 18, and was found to be 25 nm / sec in Examples 2, 4, and Comparative Example 2. Also, the dissolution rate of the photosensitive coloring composition was 60 nm / sec in Example 3, and was found to be 20 nm / sec in Examples 7, 11, 12, and 15. Further, the dissolution rate of the photosensitive coloring composition was found to be 70 nm / sec in Examples 13, 14, 16, and Comparative Example 3. Also, the dissolution rate of the photosensitive resin composition was found to be 15 nm / sec in Comparative Example 1. Thus, it was confirmed that the dissolution rate of the photosensitive coloring composition of the examples was within the range of 20 nm / sec or more and 70 nm / sec or less.

[0215] The transmittance of the cured film was 15.0% in Examples 1 to 4, 8 to 10, and 12, 11.5 in Example 5, 17.5% in Example 6, and 10.0% in Examples 7 and 11. The transmittance of the cured film was found to be 20.0% in Example 13 and 24.0% in Example 14. The transmittance of the cured film was found to be 12.5% in Examples 15 and 17, and 22.5% in Examples 16 and 18. The transmittance of the cured film was found to be 28.0% in Comparative Examples 1 and 3, and 12.5% in Comparative Example 2. Thus, according to the cured film obtained by curing the photosensitive coloring composition of the examples, it was confirmed that the transmittance was within the range of 10.0% or more and 24.0% or less. That is, it was confirmed that the cured film obtained by curing the photosensitive coloring composition of each example had a preferable transmittance for application to an infrared light cut filter for a solid-state imaging device.

[0216] The rectangularity was evaluated as 80° in Examples 1 to 4, 6, 8 to 10, 14, 16, 18, and Comparative Example 3. The rectangularity was evaluated as 85° in Example 5, and as 75° in Examples 7, 11 to 13, 15, and 17. In Comparative Example 2, it was found that no hole pattern was formed. In Comparative Example 3, although a hole pattern was formed, it was found that fusion had occurred in the hole pattern. That is, it was found that when the coating film was heated, the coating film melted, causing part of the hole pattern to adhere to other parts.

[0217] Thus, it was found that when the acrylic copolymer contained in the photosensitive coloring composition satisfies the above-mentioned conditions 1 to 4, the transmittance of the cured film is reduced and the rectangularity of the hole pattern is improved. Conversely, it was found that if even one of conditions 2 to 4 is not satisfied, it is not possible to achieve both a reduced transmittance of the cured film and an improved rectangularity of the hole pattern.

[0218] Furthermore, a comparison of the evaluation results in Example 1 and Examples 5 to 7 revealed that within the range of 5,000 to 35,000 weight-average molecular weight of the acrylic copolymer, a larger polymerization average molecular weight resulted in lower transmittance of the cured film, while within the range of 8,000 or more polymerization average molecular weight, the transmittance was 15% or less. In contrast, within the range of 5,000 to 20,000 weight-average molecular weight of the acrylic copolymer, the rectangularity evaluation result was 80° or more, while at 35,000, the rectangularity evaluation result was 75°. From these results, it can be said that, from the viewpoint of further lowering the transmittance of the cured film and further increasing the rectangularity of the hole pattern, it is preferable for the average molecular weight of the acrylic copolymer to fall within the range of 8,000 to 30,000, and more preferable for it to fall within the range of 8,000 to 20,000.

[0219] Furthermore, a comparison of the evaluation results in Example 1 and Examples 8 to 10 revealed that regardless of whether the colorant contained in the photosensitive colored composition is a cyanine dye represented by formula (6), a cyanine dye represented by formula (33), a phthalocyanine dye, or a diimonium dye, it is possible to achieve both a lower transmittance of the cured film and an improved rectangularity of the hole pattern by satisfying conditions 1 to 4 in the acrylic copolymer.

[0220] Furthermore, from a comparison of the evaluation results of Example 1 and Examples 11 to 14, it was found that the first and second ratios in Example 1 were the most preferable in terms of lowering the transmittance of the cured film and improving the rectangularity of the hole pattern. In contrast, when the first ratio was smaller than the first ratio in Example 1, it was found that the rectangularity of the hole pattern was reduced, regardless of whether the second ratio was larger or smaller than the second ratio in Example 1. Also, when the first ratio was larger than the first ratio in Example 1, and the second ratio was smaller than the second ratio in Example 1, it was found that the transmittance of the cured film was lower and the rectangularity of the hole pattern was reduced. On the other hand, when the first ratio was larger than the first ratio in Example 1, and the second ratio was larger than the second ratio in Example 1, it was found that the rectangularity of the hole pattern was maintained, but the transmittance of the cured film was increased.

[0221] Figure 5 is a triangular diagram showing the relationship between the weight of the first repeating unit, the weight of the second repeating unit, and the weight of the third repeating unit. In Figure 5, the relationships between the three repeating units in manufacturing examples 1 to 4 are shown by open white circles. In contrast, in Figure 5, the relationship between the three repeating units in manufacturing example 8 is shown by a solid black circle. Furthermore, in Figure 5, the relationship between the three repeating units in manufacturing example 9 is shown by a circle with a relatively low density of halftone dots, and the relationship between the three repeating units in manufacturing example 10 is shown by a circle with a relatively high density of halftone dots.

[0222] As shown in Figure 5, when the blending ratio of the acrylic copolymer falls in the region opposite to the region containing Production Example 9 in the direction perpendicular to the line connecting the plots of Production Example 8 and Production Example 10, the transmittance of the cured film tends to decrease. Furthermore, when the blending ratio of the acrylic copolymer falls in the region opposite to the region containing Production Example 10 in the direction perpendicular to the line connecting the plots of Production Example 8 and Production Example 9, the rectangularity of the hole pattern tends to decrease.

[0223] Figure 6 is a graph showing the relationship between the first ratio and the second ratio. In Figure 6, the results of the transmittance evaluation and the rectangularity evaluation of the cured film formed using a photosensitive colored composition that satisfies the first ratio and the second ratio at that plot are indicated near each plot.

[0224] As shown in Figure 6, in order to satisfy the criteria of a rectangularity evaluation result of 75° or more and a transmittance evaluation result of 22.5% or less, it is preferable that the first ratio and the second ratio are included within the region enclosed by the dashed lines in Figure 6. That is, it is preferable that the first ratio and the second ratio are included within the region enclosed by the first straight line connecting Example 11 and Example 12, the second straight line connecting Example 12 and Example 18, the third straight line connecting Example 18 and Example 16, the fourth straight line connecting Example 16 and Example 13, and the fifth straight line connecting Example 13 and Example 11. When the first ratio is 0.4 or more and 0.7 or less, and the second ratio is 0.03 or more and 0.08 or less, the first ratio and the second ratio are included within the region enclosed by the first to fifth straight lines, so that the transmittance of the cured film is lowered and the rectangularity is increased.

[0225] As described above, according to one embodiment of the photosensitive colored composition, the infrared light cut filter, the method for producing the photosensitive colored composition, and the method for producing the infrared light cut filter, the effects described below can be obtained.

[0226] (1) In the acrylic copolymer, the first repeating unit, the second repeating unit, and the third repeating unit are each within the range described above, so that thermal deformation of the cured film caused by heat treatment is suppressed, thereby preventing a decrease in the accuracy of the shape of the pattern formed on the cured film. In addition, in the photosensitive colored composition, the aggregation of colorants is suppressed, thereby preventing a decrease in absorbance at wavelengths in which absorption is expected in the colorants.

[0227] (2) The accuracy of the pattern shape can be improved by ensuring that the ratio of the weight of the photopolymerizable monomer to the weight of the acrylic copolymer is within the range of 0.4 to 0.7, and the ratio of the weight of the photopolymerization initiator to the weight of the photopolymerizable monomer is within the range of 0.03 to 0.08.

[0228] (3) Since the average molecular weight of the acrylic copolymer is within the range of 8,000 to 30,000, when a cured film is formed using a photosensitive coloring composition, it is possible to further suppress the decrease in absorbance of the cured film at wavelengths in which absorption is expected from the coloring agent contained in the cured film.

[0229] (4) A dissolution rate of 20 nm / second or more makes it possible to improve the precision of the pattern shape even when forming fine patterns. (5) By using cyanine dyes, it is possible to increase the solubility of the colorant in the solvent and to increase the molar extinction coefficient of the colorant.

[0230] The above-described embodiment can be implemented with the following modifications. [Barrier layer] The barrier layer 14 is not limited to being placed between the infrared light cut filter 13 and the microlenses 15R, 15G, 15B, and 15P, but may also be placed on the outer surface of each microlens 15R, 15G, 15B, and 15P.

[0231] The solid-state image sensor 10 may have an anchor layer between the barrier layer 14 and the layer below the barrier layer 14. In this case, the adhesion between the barrier layer 14 and the layer below the barrier layer 14 is enhanced by the anchor layer. Alternatively, the solid-state image sensor 10 may have an anchor layer between the barrier layer 14 and the layer above the barrier layer 14. In this case, the adhesion between the barrier layer and the layer above the barrier layer is enhanced by the anchor layer. The material forming the anchor layer is, for example, a polyfunctional acrylic resin or a silane coupling agent.

[0232] The layer structure of the barrier layer 14 may be a single layer structure consisting of a single compound, a stacked structure of layers consisting of a single compound, or a stacked structure of layers consisting of mutually different compounds.

[0233] The barrier layer 14 may also function as a planarizing layer that fills the step difference formed between the surface of the infrared light cut filter 13 and the surface of the infrared light pass filter 12P. The filter 10F for the solid-state image sensor does not need to have a barrier layer 14. Even in this case, it is possible to obtain the same effect as described in (1) above.

[0234] [others] The thicknesses of the color filters 12R, 12G, and 12B may be equal to or different from those of the infrared light pass filter 12P. For example, the thickness of the color filters 12R, 12G, and 12B may be between 0.5 μm and 5 μm.

[0235] The color filter may be a three-color filter including a cyan filter, a yellow filter, and a magenta filter. Alternatively, the color filter may be a four-color filter including a cyan filter, a yellow filter, a magenta filter, and a black filter. Alternatively, the color filter may be a four-color filter including a clear filter, a yellow filter, a red filter, and a black filter.

[0236] Each color filter 12R, 12G, and 12B may have the same thickness as the infrared light pass filter 12P, or they may have different thicknesses. The thickness of each color filter 12R, 12G, and 12B may be, for example, 0.5 μm or more and 5 μm or less.

[0237] The materials forming the infrared light cut filter 13 include additives such as light stabilizers, antioxidants, heat stabilizers, and antistatic agents, and the infrared light cut filter 13 may include additives that provide functions other than absorbing infrared light.

[0238] • In the solid-state image sensor 10, the oxygen permeability of the stacked structure located on the incident surface 15S side with respect to the infrared light cut filter 13 is 5.0 cc / m³. 2 The oxygen permeability may be less than / day / atm. For example, the laminated structure may consist of other functional layers such as a planarization layer or an adhesion layer, and together with each microlens, its oxygen permeability may be 5.0 cc / m³. 2 It can also be located below / day / atm.

[0239] The solid-state image sensor 10 may be equipped with a bandpass filter on the light incident surface side for multiple microlenses. The bandpass filter is a filter that transmits only light with specific wavelengths of visible light and near-infrared light, and has a function similar to that of an infrared light cut filter 13. That is, the bandpass filter can cut out unwanted infrared light that can be detected by the photoelectric conversion elements 11R, 11G, and 11B for each color. This makes it possible to improve the detection accuracy of visible light by the photoelectric conversion elements 11R, 11G, and 11B for each color, and the detection accuracy of near-infrared light with wavelengths in the 850nm or 940nm band, which is the target of detection by the photoelectric conversion element 11P for infrared light. [Explanation of symbols]

[0240] 10…Solid-state image sensor 13…Infrared light cut filter 10F...Filter for solid-state image sensors 11…Photoelectric conversion element 11R...Red photoelectric conversion element 11G...Photoelectric conversion element for green light 11B... Blue photoelectric conversion element 11P... Photoelectric conversion element for infrared radiation 12R…Red filter 12G...Green filter 12B... Blue filter 12P... Infrared light pass filter 13…Infrared light cut filter 13H...Through hole 14… Barrier layer 15R… Microlens for red light 15G... Microlens for green 15B... Microlens for blue light 15P… Microlens for infrared

Claims

1. A coloring agent which is a dye having an absorption maximum in the wavelength band between 700 nm and 1100 nm, Photopolymerization initiator and Photopolymerizable monomers, It contains an acrylic copolymer, The aforementioned acrylic copolymer is Represented by the following formula (1), a first repeating unit containing an epoxy group, Represented by the following formula (2), a second repeating unit derived from acrylic acid or methacrylic acid, It is represented by the following formula (3), and includes a third repeating unit containing an aromatic ring, In the aforementioned acrylic copolymer, The sum of the weights of the first repeating unit, the second repeating unit, and the third repeating unit is 87.5% by weight or more and 100% by weight or less, relative to the total weight of the acrylic copolymer. The weight of the first repeating unit is 10% by weight or more and 20% by weight or less. The weight of the second repeating unit is 12.5% ​​by weight or more and 20% by weight or less, The weight of the third repeating unit is 65% by weight or more. The ratio of the weight of the photopolymerizable monomer to the weight of the acrylic copolymer is 0.4 or more and 0.7 or less. The ratio of the weight of the photopolymerization initiator to the weight of the photopolymerizable monomer is 0.03 or more and 0.08 or less. 【Chemistry 1】 However, in formula (1), R1 is a hydrogen atom or a methyl group, and R2 is a single bond, a linear alkylene group having 1 or more carbon atoms, or a branched alkylene group having 3 or more carbon atoms. R3 is an epoxy group. 【Chemistry 2】 However, in formula (2), R4 is either a hydrogen atom or a methyl group. 【Transformation 3】 However, in formula (3), R5 is a hydrogen atom or a methyl group, and R6 is a single bond, a linear alkylene group having 1 or more carbon atoms, a branched alkylene group having 3 or more carbon atoms, or an oxyalkylene group having 1 or more carbon atoms. R7 is a hydrogen atom. Photosensitive coloring composition.

2. The weight-average molecular weight of the acrylic copolymer is 8,000 or more and 30,000 or less. The photosensitive coloring composition according to claim 1.

3. The dissolution rate in alkaline developer at 23°C is 20 nm / second or higher. The photosensitive coloring composition according to claim 1 or 2.

4. The coloring agent is selected from the group consisting of cyanine dyes, phthalocyanine dyes, squarylium dyes, crokonium dyes, diimonium dyes, dithiol metal complex dyes, naphthalocyanine dyes, and oxonol dyes. The photosensitive coloring composition according to claim 1 or 2.

5. The coloring agent is the cyanine dye. The photosensitive coloring composition according to claim 4.

6. This involves mixing a colorant, a photopolymerization initiator, a photopolymerizable monomer, and an acrylic copolymer. The aforementioned coloring agent is a dye having an absorption maximum in the wavelength band between 700 nm and 1100 nm. The aforementioned acrylic copolymer is Represented by the following formula (1), a first repeating unit containing an epoxy group, Represented by the following formula (2), a second repeating unit derived from acrylic acid or methacrylic acid, It is represented by the following formula (3), and includes a third repeating unit containing an aromatic ring, In the aforementioned acrylic copolymer, The sum of the weights of the first repeating unit, the second repeating unit, and the third repeating unit is 87.5% by weight or more and 100% by weight or less, relative to the total weight of the acrylic copolymer. The weight of the first repeating unit is 10% by weight or more and 20% by weight or less. The weight of the second repeating unit is 12.5% ​​by weight or more and 20% by weight or less, The weight of the third repeating unit is 65% by weight or more. The ratio of the weight of the photopolymerizable monomer to the weight of the acrylic copolymer is 0.4 or more and 0.7 or less. The ratio of the weight of the photopolymerization initiator to the weight of the photopolymerizable monomer is 0.03 or more and 0.08 or less. 【Transformation 7】 However, in formula (1), R1 is a hydrogen atom or a methyl group, and R2 is a single bond, a linear alkylene group having 1 or more carbon atoms, or a branched alkylene group having 3 or more carbon atoms. R3 is an epoxy group. 【Transformation 8】 However, in formula (2), R4 is either a hydrogen atom or a methyl group. 【Chemistry 9】 However, in formula (3), R5 is a hydrogen atom or a methyl group, and R6 is a single bond, a linear alkylene group having 1 or more carbon atoms, a branched alkylene group having 3 or more carbon atoms, or an oxyalkylene group having 1 or more carbon atoms. R7 is a hydrogen atom. A method for producing a photosensitive colored composition.

7. A photosensitive colored composition produced by the method for producing a photosensitive colored composition according to claim 6 is applied to a substrate to form a coating film. Exposing the coating film by irradiating a part of the coating film with light, Developing the coating after exposure, and This includes curing the coating film by heating it after development. A method for manufacturing an infrared light cut filter.

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