Pigment dispersion, composition, infrared transmitting filter, infrared sensor, and infrared camera

Abstract

Provided is a pigment dispersion capable of forming coating films which have excellent visible-light shielding properties and excellent infrared-light transparency characteristics and have low haze values. The pigment dispersion comprises (A) one or more pigments, (B) a dispersant, (C) a resin, and (D) a solvent, wherein the pigments (A) include C.I. Pigment Violet 29. When a liquid obtained by holding the pigment dispersion still at room temperature (20-30°C) for 24 hours or longer and then making an adjustment so that the concentration of the pigments (A) in the pigment dispersion is 100 mass ppm is examined by a dynamic light scattering method, the pigments (A) have a median diameter (D50) of 110 nm or less.

Description

Pigment dispersion, composition, infrared transmission filter, infrared sensor, and infrared camera

[0001] The present invention relates to a pigment dispersion, a composition, an infrared transmission filter, an infrared sensor, and an infrared camera. This application claims priority under PCT / JP2025 / 002068, filed internationally on 23 January 2025 under the Patent Cooperation Treaty, the contents of which are incorporated herein by reference.

[0002] Infrared transmission filters are used in devices such as remote control receivers and mobile phone infrared receivers because they block visible light by absorbing it, while transmitting infrared light. For example, Patent Document 1 discloses an infrared transmission filter comprising a coating formed from an infrared-transmitting colored composition containing specific amounts of copper phthalocyanine blue pigment, C.I. pigment yellow 139, and C.I. pigment violet 23, a resin-type dispersant, and a binder resin.

[0003] Japanese Patent Publication No. 2022-96923, International Publication No. 2015 / 015962

[0004] However, the infrared transmission filter described in Patent Document 1 may transmit some visible light and does not necessarily satisfy the requirement for blocking visible light. In addition, the haze value tends to increase. The color filter composition described in Patent Document 2 uses a perylene-based organic pigment and is described as having a small primary particle size of pigment. However, the color composition preparation process only contains a resin-based dispersant, which is thought to result in poor dispersion stability. Over time, the pigment particle size increases, and the infrared transmittance and haze do not necessarily satisfy the requirements. One of the objectives of the present invention is to provide a pigment dispersion, composition, infrared transmission filter, infrared sensor, and infrared camera that can form a coating film with excellent visible light shielding and infrared light transmittance and a low haze value.

[0005] The present invention has the following embodiments: [1] A pigment dispersion containing (A) a pigment, (B) a dispersant, (C) a resin, and (D) a solvent, wherein the (A) pigment contains C.I. Pigment Violet 29, and after the pigment dispersion is allowed to stand at room temperature (20-30°C) for 24 hours or more, the median diameter (D50) of the (A) pigment observed by dynamic light scattering is 110 nm or less for a solution adjusted to a concentration of 100 ppm by mass of the pigment (A) in the pigment dispersion. [2] The pigment dispersion of [1], wherein after the pigment dispersion is allowed to stand at room temperature (20-30°C) for 24 hours or more, the difference (D85-D15) between the particle diameter (D85) of the (A) pigment and the particle diameter (D15) of the (A) pigment observed by dynamic light scattering is 50 nm or less for a solution adjusted to a concentration of 100 ppm by mass of the pigment (A) in the pigment dispersion. [3] A pigment dispersion of [1] or [2], wherein the content of the (C) resin is 40 to 300 parts by mass per 100 parts by mass of the (A) pigment. [4] A pigment dispersion of any of [1] to [3], wherein the coating film formed from the pigment dispersion has a thickness of 1.7 μm and satisfies the following condition (1): Condition (1): The maximum transmittance of light at a wavelength of 450 to 600 nm is 4% or less. [5] A pigment dispersion of any of [1] to [4], wherein the coating film formed from the pigment dispersion has a thickness of 1.7 μm and satisfies the following condition (2): Condition (2): The minimum transmittance of light at a wavelength of 850 to 1000 nm is 90% or more. [6] A pigment dispersion of any of [1] to [5], wherein the coating film formed from the pigment dispersion has a thickness of 1.7 μm and satisfies the following condition (3). Condition (3): The difference in wavelength (λ2-λ1) between the maximum wavelength λ1 at which the light transmittance is 20% and the minimum wavelength λ2 at which the light transmittance is 90% is 50 nm or less. [7] Any of the pigment dispersions from [1] to [6], wherein the content of C.I. Pigment Violet 29 is 1 to 70% by mass relative to the total mass of the (A) pigment. [8] Any of the pigment dispersions from [1] to [7], wherein the viscosity of the pigment dispersion at 23°C, as measured by an E-type rotational viscometer, is 9 mPa·s or more. [9] Any of the pigment dispersions from [1] to [8], wherein the (A) pigment further comprises at least one of C.I. Pigment Blue 15:6 and C.I. Pigment Yellow 139.

[10] A pigment dispersion according to any of [1] to [9], wherein the content of the (B) dispersant is 33 to 250 parts by mass per 100 parts by mass of the (A) pigment.

[11] A pigment dispersion according to any of [1] to

[10] , wherein the content of the (A) pigment is 1 to 30% by mass relative to the total mass of the pigment dispersion.

[12] A pigment dispersion according to any of [1] to

[11] , wherein the (C) resin comprises either or both epoxy (meth)acrylate resins and acrylic copolymer resins, other than the (B) dispersant.

[13] A pigment dispersion according to any of [1] to

[12] , wherein the (B) dispersant comprises either or both urethane polymer dispersants and acrylic polymer dispersants having functional groups.

[14] A composition comprising one or more resins selected from polycarbonate resins, acrylic resins and epoxy resins, and the pigment dispersion according to any of [1] to

[13] . An infrared-transmitting filter having a coating film formed using any of the pigment dispersions of

[15] [1] to

[13] . An infrared-transmitting filter having a coating film formed using the composition of

[16]

[14] . An infrared sensor having the infrared-transmitting filter of

[17]

[15] . An infrared sensor having the infrared-transmitting filter of

[18]

[16] . An infrared camera having the infrared-transmitting filter of

[19]

[15] . An infrared camera having the infrared-transmitting filter of

[20]

[16] .

[21] A method for producing a pigment dispersion containing (A) a pigment, (B) a dispersant, (C) a resin and (D) a solvent, comprising mixing (A) a pigment, (B) a dispersant, (C) a resin and (D) a solvent, wherein (A) the pigment is C.I. A method for producing a pigment dispersion, comprising pigment violet 29, wherein the pigment dispersion is allowed to stand at room temperature (20-30°C) for 24 hours or more, and after adjusting the concentration of pigment (A) in the pigment dispersion to 100 ppm by mass, the median diameter (D50) of pigment (A) observed by dynamic light scattering is 110 nm or less.

[22] A method for producing the pigment dispersion according to

[21] , wherein a coating film with a thickness of 1.7 μm formed from the pigment dispersion satisfies the following condition (1): The maximum transmittance of light at wavelengths of 450-600 nm is 4% or less.

[23] A method for producing the pigment dispersion according to

[21] or

[22] , wherein a coating film with a thickness of 1.7 μm formed from the pigment dispersion satisfies the following condition (2).Condition (2): The minimum light transmittance at wavelengths of 850 to 1000 nm is 90% or more.

[24] A method for producing a pigment dispersion according to any of

[21] to

[23] , wherein the coating film formed from the pigment dispersion has a thickness of 1.7 μm and satisfies the following condition (3): Condition (3): The difference in wavelength (λ2-λ1) between the maximum wavelength λ1 at which the light transmittance is 20% and the minimum wavelength λ2 at which the light transmittance is 90% is 50 nm or less.

[25] A method for producing a pigment dispersion according to any of

[21] to

[24] , wherein the content of the C.I. pigment violet 29 is 1 to 70% by mass relative to the total mass of the pigment (A).

[26] A method for producing a pigment dispersion according to any of

[21] to

[25] , wherein the optical density per 1 μm of film thickness of the coating film formed from the pigment dispersion is 0.5 or more.

[27] A method for producing a pigment dispersion containing (A) a pigment, (B) a dispersant, (C) a resin, and (D) a solvent, comprising mixing (A) a pigment, (B) a dispersant, (C) a resin, and (D) a solvent, wherein (A) the pigment is a perylene-based pigment having absorption in 400 to 650 nm, and the perylene-based pigment having a primary particle size of 20 to 150 nm as measured by scanning electron microscopy (TEM), (B) a dispersant, and (D) a solvent are dispersed using a jet mill, paint shaker, or ball mill, the pigment dispersion is left to stand at room temperature (20 to 30°C) for 24 hours or more, and the median diameter (D50) of the perylene-based pigment in the pigment dispersion, as observed by dynamic light scattering, is 110 nm or less.

[28] The method for producing a pigment dispersion according to

[27] , wherein the content of the dispersant (B) is 33 to 250 parts by mass per 100 parts by mass of the pigment (A).

[0006] According to one aspect of the present invention, a pigment dispersion, composition, infrared transmission filter, infrared sensor, and infrared camera can be provided that can form a coating film with excellent visible light shielding and infrared light transmission properties and a low haze value.

[0007] The embodiments of the present invention will be described below in detail, but the present invention is not limited to the embodiments described below and can be implemented with various modifications within the scope of its gist. In the present invention, the following terms have the following meanings: A numerical range expressed using "~" means a range that includes the numbers written before and after "~" as the lower limit and upper limit. For example, A to B is synonymous with A or more and B or less. In this specification, a percentage or part expressed in "mass" is synonymous with a percentage or part expressed in "weight". "A and / or B" means "either A or B or both". The numerical ranges of content, various physical properties, and property values ​​disclosed herein can be changed to new numerical ranges by arbitrarily combining their lower and upper limits.

[0008] In the present invention and this specification, the following terms have the following meanings: "Visible light" means light in the wavelength range of 380 to 780 nm (visible region). "Infrared light" means light in the wavelength range of 780 nm to 1 mm (infrared region). In particular, light in the wavelength range of 780 to 2500 nm is also called "near-infrared light". "C.I." means color index. "Median diameter (D50)" means the particle diameter that represents 50% of the cumulative volume-based particle size distribution measured by dynamic light scattering (DLS). The median diameter is useful as a method for observing the dispersion state of pigments, and a small median diameter indicates less pigment aggregation, making it easier to exhibit the low haze performance expected of the present invention. The median diameter (D50) is the particle diameter that represents 50% of the cumulative volume-based particle size distribution when the pigment concentration in the pigment dispersion exceeds 100 ppm by mass, after the pigment dispersion has been allowed to stand at room temperature (20-30°C) for 24 hours or more, 0.002-0.003 g of the pigment dispersion has been diluted with an organic solvent to a pigment concentration of 100 ppm by mass, stirred with a vortex mixer, and then measured at room temperature using a particle size distribution analyzer that measures the volume-based particle size distribution by dynamic light scattering (for example, Otsuka Electronics Co., Ltd., product name "Concentrated Particle Size Analyzer FPAR-1000" can be used). When the pigment concentration in the pigment dispersion is 100 ppm by mass or less, the particle size is the particle size that represents 50% of the cumulative volume-based particle size distribution when the pigment dispersion is left to stand at room temperature (20-30°C) for 24 hours or more, without changing the pigment concentration in the pigment dispersion, and measured at room temperature using a particle size distribution analyzer by dynamic light scattering (DLS) (for example, Otsuka Electronics Co., Ltd., product name "Concentrated Particle Size Analyzer FPAR-1000" can be used). For standing, the sample prepared in a vial is sealed, dissolved and stirred, and then left on a desk in a room controlled to a specific temperature by air conditioning. "Particle size (D15)" means the particle size that represents 15% of the cumulative volume-based particle size distribution measured by dynamic light scattering (DLS). "Particle size (D85)" means the particle size that represents 85% of the cumulative volume-based particle size distribution measured by dynamic light scattering (DLS). "Coating film" means the film formed using the pigment dispersion.The coating film may be a film formed using only the pigment dispersion (hereinafter also referred to as "coating film (F1)") or a film formed by adding additives to the pigment dispersion (hereinafter also referred to as "coating film (F2)"). In this specification, coating film (F1) and coating film (F2) are collectively referred to as "coating film (F)". "Total solids content of the pigment dispersion" means all components in the pigment dispersion other than the (D) solvent, i.e., the components that constitute the coating film (F1) (hereinafter also referred to as "film-forming components"). "Total solids content of the pigment dispersion" means the sum of the film-forming components contained. Even if components other than the (D) solvent are liquid at room temperature, those components are not included in the (D) solvent but are included in the total solids content. "(meth)acrylic" means "either acrylic or methacrylic or both". The same applies to "(meth)acrylate" and "(meth)acryloyl". "Acid (anhydride)" and "(anhydride)...acid" mean including both the acid and its anhydride. "Monomer" is a term used in contrast to so-called polymers, and in addition to monomers in the narrow sense, it also includes dimers, trimers, and oligomers. "Weight-average molecular weight" refers to the weight-average molecular weight (Mw) in polystyrene terms, calculated by GPC (gel permeation chromatography). "Amine value" refers to the amine value in terms of effective solids unless otherwise specified, and is expressed as the amount of base and the mass of equivalent KOH per gram of solids of (B) dispersant. The measurement method will be described later. "Acid value" refers to the acid value in terms of effective solids unless otherwise specified, and is calculated by neutralization titration.

[0009] [Pigment Dispersion] The pigment dispersion contains (A) pigment, (B) dispersant, (C) resin, and (D) solvent. The pigment dispersion may further contain, as necessary, components other than (A) pigment, (B) dispersant, (C) resin, and (D) solvent (hereinafter also referred to as "optional components"), in addition to (A) pigment, (B) dispersant, (C) resin, and (D) solvent, as long as the effects of the present invention are not impaired.

[0010] <(A) Pigment> The pigment dispersion contains (A) pigment. (A) pigment is a component that colors the pigment dispersion. By containing (A) pigment in the pigment dispersion, the desired light absorption can be obtained. (A) pigment contains C.I. Pigment Violet 29. (A) pigment preferably further contains at least one of a blue pigment and a yellow pigment in addition to C.I. Pigment Violet 29, and more preferably both of the blue pigment and the yellow pigment. That is, (A) pigment more preferably contains C.I. Pigment Violet 29, a blue pigment and a yellow pigment. (A) pigment may further contain, as necessary, pigments other than C.I. Pigment Violet 29, blue pigment and yellow pigment (hereinafter also referred to as "other pigments") in addition to C.I. Pigment Violet 29, blue pigment and yellow pigment, as long as it does not impair the effects of the present invention.

[0011] (C.I. Pigment Violet 29) C.I. Pigment Violet 29 is a dark reddish-purple perylene-based pigment that, in solution, exhibits an absorption spectrum with absorption over a wide range of visible light, specifically from 400 to 650 nm. C.I. Pigment Violet 29 is a pigment with excellent visible light shielding properties, exhibiting superior light shielding across a wide range of visible light. Therefore, sufficient visible light shielding can be obtained even with a small amount of pigment. Generally, as the pigment content increases, in addition to the decrease in visible light transmittance, the infrared light transmittance also tends to decrease. Although the decrease in infrared light transmittance is smaller compared to visible light transmittance, the infrared light transmittance decreases. However, since C.I. Pigment Violet 29 provides sufficient visible light shielding even with a small amount of pigment, there is no need to add excessive amounts, which suppresses the decrease in infrared light transmittance and allows for the formation of a coating film (F) that is excellent in both visible light shielding and infrared light transmittance.

[0012] The median diameter (D50) of C.I. Pigment Violet 29 is preferably 110 nm or less, more preferably 100 nm or less, even more preferably 90 nm or less, and also preferably 60 nm or more, more preferably 65 nm or more, and even more preferably 70 nm or more. The above upper and lower limits can be arbitrarily combined. For example, the median diameter (D50) of C.I. Pigment Violet 29 is preferably 60 to 110 nm, more preferably 65 to 100 nm, and even more preferably 70 to 90 nm. If the median diameter (D50) of C.I. Pigment Violet 29 is above the above lower limit, C.I. Pigment Violet 29 is less likely to aggregate over time, and high transmittance can be maintained. If the median diameter (D50) of the pigment violet 29 is below the above upper limit, scattered light is further reduced, and a coating (F) with a lower haze value can be formed.

[0013] The particle size (D15) of C.I. Pigment Violet 29 is preferably 105 nm or less, more preferably 95 nm or less, even more preferably 85 nm or less, and also preferably 55 nm or more, more preferably 60 nm or more, and even more preferably 65 nm or more. The above upper and lower limits can be combined arbitrarily. For example, the particle size (D15) of C.I. Pigment Violet 29 is preferably 55 to 105 nm, more preferably 60 to 95 nm, and even more preferably 65 to 85 nm. If the particle size (D15) of C.I. Pigment Violet 29 is above the lower limit, the C.I. Pigment Violet 29 is less likely to aggregate over time, and high transmittance can be maintained. If the particle size (D15) of C.I. Pigment Violet 29 is below the upper limit, scattered light is further reduced, and a coating film (F) with a lower haze value can be formed.

[0014] The particle size (D85) of C.I. Pigment Violet 29 is preferably 115 nm or less, more preferably 105 nm or less, even more preferably 95 nm or less, and also preferably 65 nm or more, more preferably 70 nm or more, and even more preferably 75 nm or more. The above upper and lower limits can be combined arbitrarily. For example, the particle size (D85) of C.I. Pigment Violet 29 is preferably 65 to 115 nm, more preferably 70 to 105 nm, and even more preferably 75 to 95 nm. If the particle size (D85) of C.I. Pigment Violet 29 is above the lower limit, the C.I. Pigment Violet 29 is less likely to aggregate over time, and high transmittance can be maintained. If the particle size (D85) of C.I. Pigment Violet 29 is below the upper limit, scattered light is further reduced, and a coating film (F) with a lower haze value can be formed.

[0015] (Blue Pigments) Examples of blue pigments include C.I. Pigment Blue 1, 1:2, 9, 14, 15, 15:1, 15:2, 15:3, 15:4, 15:6, 16, 17, 19, 25, 27, 28, 29, 33, 35, 36, 56, 56:1, 60, 61, 61:1, 62, 63, 66, 67, 68, 71, 72, 73, 74, 75, 76, 78, and 79. From the viewpoint of visible light shielding, C.I. Pigment Blue 15, 15:1, 15:2, 15:3, 15:4, 15:6, and 60 are preferred, and C.I. Pigment Blue 15:6 is more preferred. From the viewpoint of dispersibility and visible light shielding, C.I. Pigment blue in a ratio of 15:6, 16, or 60 is preferred, and C.I. pigment blue in a ratio of 15:6 is more preferred. The blue pigment may be used alone or in combination of two or more types.

[0016] (Yellow Pigment) Examples of yellow pigments include C.I. Pigment Yellow 1, 1:1, 2, 3, 4, 5, 6, 9, 10, 12, 13, 14, 16, 17, 24, 31, 32, 34, 35, 35:1, 36, 36:1, 37, 37:1, 40, 41, 42, 43, 48, 53, 55, 61, 62, 62:1, 63, 65, 73, 74, 75, 81, 83, 87, 93, 94, 95, 97, 100, 101, 104, 105, 108, 109, 110, 111, 116, 117, 119, 120, 126, 127, 127:1, 128, 129, 133, 134, 136, 138, 139, 142, 147, 148, 150, 151, 153, 154, 155, 157, 158, 159, 160, 161, 162, 163, 164, 165, 166, 167, 168, 169, 170, 172, 173, 174, 175, 176, 180, 181, 182, 183, 184, 185, 188, 189, 190, 191, 191:1, 192, 193, 194, 195, 196, 197, 198, 199, 200, 202, 203, 204, 205, 206, 207, 208 are listed. In terms of infrared light transmittance, C.I. Pigment yellows 83, 117, 129, 138, 139, 150, 154, 155, 180, and 185 are preferred, C.I. Pigment Yellows 83, 138, 139, 150, and 180 are more preferred, and C.I. Pigment Yellow 139 is even more preferred. The yellow pigment may be used alone or in combination of two or more types.

[0017] From the viewpoint of maintaining a good balance between shielding of visible light and transmittance of infrared light, (A) the pigment preferably contains at least one of C.I. Pigment Blue 15:6 and C.I. Pigment Yellow 139 in addition to C.I. Pigment Violet 29, and more preferably contains C.I. Pigment Violet 29, C.I. Pigment Blue 15:6 and C.I. Pigment Yellow 139.

[0018] (Other Pigments) Other pigments include purple pigments other than C.I. Pigment Violet 29 (hereinafter also referred to as "other purple pigments"), red pigments, orange pigments, green pigments, and black pigments. Other pigments may be used individually or in combination of two or more.

[0019] Other purple pigments include, for example, C.I. Pigment Violet 1, 1:1, 2, 2:2, 3, 3:1, 3:3, 5, 5:1, 14, 15, 16, 19, 23, 25, 27, 31, 32, 37, 39, 42, 44, 47, 49, and 50. These other purple pigments may be used individually or in combination of two or more.

[0020] Examples of red pigments include C.I. Pigment Red 1, 2, 3, 4, 5, 6, 7, 8, 9, 12, 14, 15, 16, 17, 21, 22, 23, 31, 32, 37, 38, 41, 47, 48, 48:1, 48:2, 48:3, 48:4, 49, 49:1, 49:2, 50:1, 52:1, 52:2, 53, 53:1, 53:2, 53:3, 57, 57:1 , 57:2, 58:4, 60, 63, 63:1, 63:2, 64, 64:1, 68, 69, 81, 81:1, 81:2, 81:3, 81:4, 83, 88, 90:1, 101, 101:1, 104, 108, 108:1, 109, 112, 113, 114, 122, 123, 144, 146, 147, 149, 151, 1 66, 168, 169, 170, 172, 173, 174, 175, 176, 177, 178, 179, 181, 184, 185, 187, 188, 190, 193, 194, 200, 202, 206, 207, 208, 209, 210, 214, 216, 220, 221, 224, 230, 231, 232, 233, 2 Examples include 35, 236, 237, 238, 239, 242, 243, 245, 247, 249, 250, 251, 253, 254, 255, 256, 257, 258, 259, 260, 262, 263, 264, 265, 266, 267, 268, 269, 270, 271, 272, 273, 274, 275, and 276. Red pigments may be used individually or in combination of two or more types.

[0021] Examples of orange pigments include C.I. Pigment Orange 1, 2, 5, 13, 16, 17, 19, 20, 21, 22, 23, 24, 34, 36, 38, 39, 43, 46, 48, 49, 61, 62, 64, 65, 67, 68, 69, 70, 71, 72, 73, 74, 75, 77, 78, and 79. Orange pigments may be used individually or in combination of two or more types.

[0022] Examples of green pigments include C.I. Pigment Green 1, 2, 4, 7, 8, 10, 13, 14, 15, 17, 18, 19, 26, 36, 45, 48, 50, 51, 54, 55, 58, and 59. A single green pigment may be used, or two or more may be used in combination.

[0023] Examples of black pigments include organic black pigments such as perylene-based black pigments, aniline-based black pigments, and benzodifuranone-based black pigments; and inorganic black pigments such as carbon black, acetylene black, lamp black, bone black, graphite, iron black, cyanine black, and titanium black. A single black pigment may be used, or two or more may be used in combination.

[0024] (Particle size) The median diameter (D50) of pigment (A) is 110 nm or less, preferably 100 nm or less, more preferably 90 nm or less, preferably 60 nm or more, more preferably 65 nm or more, and even more preferably 70 nm or more. The above upper and lower limits can be combined arbitrarily. For example, the median diameter (D50) of pigment (A) is preferably 60 to 110 nm, more preferably 65 to 100 nm, and even more preferably 70 to 90 nm. If the median diameter (D50) of pigment (A) is above the lower limit, the pigment (A) is less likely to aggregate over time, and high transmittance can be maintained. If the median diameter (D50) of pigment (A) is below the upper limit, scattered light is reduced, and a coating film (F) with a low haze value can be formed.

[0025] (A) The particle size (D15) of the pigment is preferably 105 nm or less, more preferably 95 nm or less, even more preferably 85 nm or less, and also preferably 55 nm or more, more preferably 60 nm or more, and even more preferably 65 nm or more. The above upper and lower limits can be combined arbitrarily. For example, the particle size (D15) of the pigment is preferably 55 to 105 nm, more preferably 60 to 95 nm, and even more preferably 65 to 85 nm. If the particle size (D15) of the pigment is above the lower limit, the pigment is less likely to aggregate over time, and a high transmittance can be maintained. If the particle size (D15) of the pigment is below the upper limit, scattered light is further reduced, and a coating film (F) with a lower haze value can be formed.

[0026] (A) The particle size (D85) of the pigment is preferably 115 nm or less, more preferably 105 nm or less, even more preferably 95 nm or less, and also preferably 65 nm or more, more preferably 70 nm or more, and even more preferably 75 nm or more. The above upper and lower limits can be combined arbitrarily. For example, (A) the particle size (D85) of the pigment is preferably 65 to 115 nm, more preferably 70 to 105 nm, and even more preferably 75 to 95 nm. If the particle size (D85) of the pigment is above the lower limit, the C.I. Pigment Violet 29 is less likely to aggregate over time, and a high transmittance can be maintained. If the particle size (D85) of the pigment is below the upper limit, scattered light is further reduced, and a coating film (F) with a lower haze value can be formed.

[0027] The difference (D85-D15) between the particle size of pigment (A) (D85) and the particle size of pigment (A) (D15) is preferably 50 nm or less, more preferably 48 nm or less, and even more preferably 45 nm or less. If the difference (D85-D15) is less than or equal to the above upper limit, scattered light is further reduced, and a coating film (F) with a lower haze value can be formed.

[0028] (Content) The content of C.I. Pigment Violet 29 is preferably 1% by mass or more, more preferably 10% by mass or more, even more preferably 20% by mass or more, particularly preferably 25% by mass or more, and also preferably 70% by mass or less, more preferably 65% ​​by mass or less, and even more preferably 60% by mass or less, based on the total mass of the pigment (A). The above upper and lower limits can be combined arbitrarily. For example, the content of C.I. Pigment Violet 29 is preferably 1 to 70% by mass, more preferably 10 to 70% by mass, even more preferably 20 to 65% by mass, and particularly preferably 25 to 60% by mass, based on the total mass of the pigment (A). If the content of C.I. Pigment Violet 29 is above the lower limit, the visible light shielding performance of the coating film (F) is further improved. If the content of C.I. Pigment Violet 29 is below the upper limit, the infrared light transmittance of the coating film (F) is further improved.

[0029] The content of C.I. Pigment Violet 29 is preferably 0.5% by mass or more, more preferably 3% by mass or more, even more preferably 5% by mass or more, and preferably 35% by mass or less, more preferably 30% by mass or less, and even more preferably 25% by mass or less, based on the total mass of the total solid content of the pigment dispersion. The above upper and lower limits can be combined arbitrarily. For example, the content of C.I. Pigment Violet 29 is preferably 0.5 to 35% by mass, more preferably 3 to 30% by mass, and even more preferably 5 to 25% by mass, based on the total mass of the total solid content of the pigment dispersion. If the content of C.I. Pigment Violet 29 is above the lower limit, the visible light shielding performance of the coating film (F) is further improved. If the content of C.I. Pigment Violet 29 is below the upper limit, the infrared light transmittance of the coating film (F) is further improved.

[0030] When the pigment dispersion contains blue pigment and / or yellow pigment, the amounts of blue pigment and yellow pigment are not particularly limited, but it is preferable that the amount is such that the optical density per 1 μm of film thickness of the coating film (F1) formed from the pigment dispersion (hereinafter also referred to as "OD per unit film thickness" or "unit OD") is 0.5 or more, or that the coating film (F1) satisfies one or more of the conditions (1) to (3) described later. For example, if the amounts of blue pigment and yellow pigment are within the ranges shown below, the unit OD is likely to be 0.5 or more, and the coating film (F1) is likely to satisfy one or more of the conditions (1) to (3) described later.

[0031] The content of the blue pigment is preferably 5% by mass or more, more preferably 10% by mass or more, even more preferably 15% by mass or more, and preferably 60% by mass or less, more preferably 55% by mass or less, and even more preferably 50% by mass or less, based on the total mass of the pigment (A). The above upper and lower limits can be combined arbitrarily. For example, the content of the blue pigment is preferably 5 to 60% by mass, more preferably 10 to 55% by mass, and even more preferably 15 to 50% by mass, based on the total mass of the pigment (A). If the content of the blue pigment is above the lower limit, the visible light shielding properties of the coating film (F) are further improved. If the content of the blue pigment is below the upper limit, the infrared light transmittance of the coating film (F) is further improved.

[0032] The blue pigment content is preferably 1% by mass or more, more preferably 3% by mass or more, even more preferably 5% by mass or more, and also preferably 35% by mass or less, more preferably 30% by mass or less, and even more preferably 25% by mass or less, based on the total mass of the total solid content of the pigment dispersion. The above upper and lower limits can be combined arbitrarily. For example, the blue pigment content is preferably 1 to 35% by mass, more preferably 3 to 30% by mass, and even more preferably 5 to 25% by mass, based on the total mass of the total solid content of the pigment dispersion. If the blue pigment content is above the lower limit, the visible light shielding properties of the coating film (F) are further improved. If the blue pigment content is below the upper limit, the infrared light transmittance of the coating film (F) is further improved.

[0033] The content of the yellow pigment is preferably 1% by mass or more, more preferably 3% by mass or more, even more preferably 5% by mass or more, and preferably 45% by mass or less, more preferably 40% by mass or less, and even more preferably 35% by mass or less, based on the total mass of the pigment (A). The above upper and lower limits can be combined arbitrarily. For example, the content of the yellow pigment is preferably 1 to 45% by mass, more preferably 3 to 40% by mass, and even more preferably 5 to 35% by mass, based on the total mass of the pigment (A). If the content of the yellow pigment is above the lower limit, the visible light shielding properties of the coating film (F) are further improved. If the content of the yellow pigment is below the upper limit, the infrared light transmittance of the coating film (F) is further improved.

[0034] The content of the yellow pigment is preferably 1% by mass or more, more preferably 2% by mass or more, even more preferably 3% by mass or more, and preferably 30% by mass or less, more preferably 25% by mass or less, and even more preferably 20% by mass or less, based on the total mass of the total solid content of the pigment dispersion. The above upper and lower limits can be combined arbitrarily. For example, the content of the yellow pigment is preferably 1 to 30% by mass, more preferably 2 to 25% by mass, and even more preferably 3 to 20% by mass, based on the total mass of the total solid content of the pigment dispersion. If the content of the yellow pigment is above the lower limit, the visible light shielding properties of the coating film (F) are further improved. If the content of the yellow pigment is below the upper limit, the infrared light transmittance of the coating film (F) is further improved.

[0035] If the pigment dispersion contains other pigments, the amount of other pigments is not particularly limited, but it is preferable that the amount is such that the unit OD of the coating film (F1) formed from the pigment dispersion is 0.5 or more, or that the coating film (F1) satisfies one or more of the following conditions (1) to (3). In particular, from the viewpoint of having an excellent balance between visible light shielding and infrared light transmission, the content of C.I. Pigment Violet 23 is preferably less than 15% by mass, more preferably 10% by mass or less, even more preferably 5% by mass or less, even more preferably 1% by mass or less, especially preferably 0.1% by mass or less, and especially preferably substantially absent, relative to the total mass of the pigment (A). The content of C.I. Pigment Violet 23 is preferably 10% by mass or less, more preferably 5% by mass or less, even more preferably 1% by mass or less, especially preferably 0.1% by mass or less, relative to the total mass of the total solid content of the pigment dispersion, and especially preferably substantially absent. Here, "substantially absent" means that, excluding unintentional inclusions, C.I. Pigment Violet 23 is not actively incorporated into the pigment dispersion.

[0036] <(B) Dispersant> The pigment dispersion contains a (B) dispersant. The inclusion of a (B) dispersant in the pigment dispersion allows for the fine dispersion of (A) pigments in the (D) solvent and stabilizes the dispersion state of (A) pigments. The (B) dispersant has pigment affinity sites and compatible sites that have the property of adsorbing to pigments, and has the effect of weakening the cohesive force between pigments and enabling the micronization of pigments. Specifically, polymeric dispersants having functional groups are preferred, and even more preferred from the viewpoint of interaction with pigments are polymeric dispersants having functional groups such as carboxyl groups; phosphate groups; sulfonic acid groups; or their bases; primary, secondary, or tertiary amino groups; quaternary ammonium groups; and nitrogen-containing heterocycle-derived groups such as pyridine, pyrimidine, and pyrazine. Polymeric dispersants having basic functional groups such as primary, secondary, or tertiary amino groups; quaternary ammonium groups; and nitrogen-containing heterocycle-derived groups such as pyridine, pyrimidine, and pyrazine are particularly preferred from the viewpoint that pigments can be dispersed with a small amount of dispersant.

[0037] Examples of polymer dispersants include urethane-based dispersants, acrylic-based dispersants, polyethyleneimine-based dispersants, polyallylamine-based dispersants, dispersants composed of monomers and macromonomers having amino groups, polyoxyethylene alkyl ether-based dispersants, polyoxyethylene diester-based dispersants, polyether phosphate-based dispersants, polyester phosphate-based dispersants, sorbitan aliphatic ester-based dispersants, and aliphatic-modified polyester-based dispersants.

[0038] Examples of such dispersants include, by trade name, EFKA (registered trademark, manufactured by BASF), DISPERBYK (registered trademark, manufactured by Bic Chemie), Disparon (registered trademark, manufactured by Kusumoto Chemical Co., Ltd.), SOLSPERSE (registered trademark, manufactured by Lubrizol), KP (manufactured by Shin-Etsu Chemical Co., Ltd.), Polyflow (manufactured by Kyoeisha Chemical Co., Ltd.), and Azisper (registered trademark, manufactured by Ajinomoto Co., Ltd.). Polymeric dispersants may be used individually or in combination of two or more.

[0039] (A) From the viewpoint of pigment dispersibility, (B) dispersant preferably contains either or both of a urethane-based polymer dispersant and an acrylic-based polymer dispersant having functional groups, and particularly preferably contains an acrylic-based polymer dispersant. From the viewpoint of dispersibility and preservation, a polymer dispersant having basic functional groups and either or both of polyester bonds and polyether bonds is preferred. When (B) dispersant contains a urethane-based polymer dispersant, the content of the urethane-based polymer dispersant is preferably 50% by mass or more, more preferably 60% by mass or more, and even more preferably 70% by mass or more. There is no particular upper limit, but it is usually 100% by mass. When (B) dispersant contains an acrylic-based polymer dispersant, the content of the acrylic-based polymer dispersant is preferably 50% by mass or more, more preferably 60% by mass or more, and even more preferably 70% by mass or more. There is no particular upper limit, but it is usually 100% by mass. (B) When using both urethane-based polymer dispersants and acrylic-based polymer dispersants as dispersants, the content ratio of urethane-based polymer dispersants to acrylic-based polymer dispersants is preferably 30:70 to 5:95, and more preferably 20:80 to 10:90.

[0040] Examples of urethane-based and acrylic polymer dispersants include the DISPERBY K-160 to 167 and 182 series (all urethane-based), DISPERBY K-2000, 2001, BYK-LPN6919, and BYK-LPN21116 (all acrylic-based) (all manufactured by Bic Chemie).

[0041] The amine value of the polymeric dispersant having a basic functional group is not particularly limited, but is preferably 1 mg KOH / g or more, more preferably 10 mg KOH / g or more, even more preferably 20 mg KOH / g or more, even more preferably 40 mg KOH / g or more, particularly preferably 50 mg KOH / g or more, and also preferably 200 mg KOH / g or less, more preferably 180 mg KOH / g or less, even more preferably 160 mg KOH / g or less, even more preferably 140 mg KOH / g or less, and particularly preferably 120 mg KOH / g or less. The above upper and lower limits can be arbitrarily combined. For example, the amine value of the polymeric dispersant having a basic functional group is preferably 1 to 200 mg KOH / g, more preferably 10 to 180 mg KOH / g, even more preferably 20 to 160 mg KOH / g, even more preferably 40 to 140 mg KOH / g, and particularly preferably 50 to 120 mg KOH / g. If the amine value of the polymeric dispersant having a basic functional group is above the lower limit mentioned above, the dispersibility tends to be good. If the amine value of the polymeric dispersant having a basic functional group is below the upper limit mentioned above, the compatibility with the (C) resin described later tends to be good.

[0042] From the viewpoint of dispersibility, an acrylic dispersant is preferably an A-B or B-A-B block copolymer composed of an A block having the above-mentioned functional groups and a B block not having the above-mentioned functional groups. In this case, the A block may contain not only substructures derived from unsaturated group-containing monomers containing the above-mentioned functional groups, but also substructures derived from unsaturated group-containing monomers not containing the above-mentioned functional groups, and these may be contained in the A block in either a random copolymerization or a block copolymerization. The content of substructures not containing functional groups in the A block is preferably 80% by mass or less, more preferably 50% by mass or less, even more preferably 30% by mass or less, even more preferably 10% by mass or less, and particularly preferably 0% by mass.

[0043] From the viewpoint of dispersibility, it is preferable that the B block consists only of substructures derived from unsaturated group-containing monomers that do not contain the above-mentioned functional groups. A single B block may contain substructures derived from two or more monomers, and these may be contained in the B block in either a random copolymerization or a block copolymerization manner. The A-B or B-A-B block copolymer is prepared, for example, by the living polymerization method shown below. Living polymerization methods include anionic living polymerization, cationic living polymerization, and radical living polymerization. Of these, anionic living polymerization uses an anion as the polymerization active species and is represented, for example, by the scheme shown below.

[0044]

[0045] In the above scheme, Ar １ Ar is a monovalent organic group. ２ Ar １ It is a different monovalent organic group, where M is a metal atom, and s and t are integers greater than or equal to 1.

[0046] Radical living polymerization uses radical polymerization active species, as shown in the following scheme, for example.

[0047]

[0048] In the above scheme, Ar １ Ar is a monovalent organic group. ２is Ar １ is a monovalent organic group different from that, and j and k are each an integer of 1 or more, and R ａ is a hydrogen atom or a monovalent organic group, and R ｂ is R ａ is a hydrogen atom or a monovalent organic group different from R

[0049] When synthesizing this acrylic dispersant, for example, Japanese Patent Laid-Open No. 9-62002, P. Lutz, P. Masson et al, Polym. Bull. 12, 79 (1984), B. C. Anderson, G. D. Andrews et al, Macromolecules, 14, 1601 (1981), K. Hatada, K. Ute, et al, Polym. J. 17, 977 (1985), K. Hatada, K. Ute, et al, Polym. J. 18, 1037 (1986), Koichi Migita, Koichi Hatada, Polymer Processing, 36, 366 (1987), Toshinobu Higashimura, Mitsuo Sawamoto, Polymer Symposium, 46, 189 (1989), M. Kuroki, T. Aida, J. Am. Chem. Sic, 109, 4737 (1987), Takuzo Aida, Shohei Inoue, Journal of Organic Synthetic Chemistry, 43, 300 (1985), D. Y. Sogoh, W. R. Hertler et al, Macromolecules, 20, 1473 (1987), the known methods described therein can be employed.

[0050] The acrylic dispersant that can be used in the present invention may be an A-B block copolymer or a B-A-B block copolymer, and the A block / B block ratio constituting the copolymer is not particularly limited, and 1 / 99 to 80 / 20 (mass ratio) is preferable, and 5 / 95 to 60 / 40 (mass ratio) is more preferable. By setting it within this range, it tends to be easy to ensure the balance between dispersibility and storage stability. The amount of the quaternary ammonium group in 1 g of the A-B block copolymer and the B-A-B block copolymer that can be used in the present invention is preferably 0.1 to 10 mmol. By setting it within this range, it tends to be easy to ensure good dispersibility.

[0051] Such acrylic dispersants may contain amino groups. The amine value of the acrylic dispersant is preferably 1 mg KOH / g or more, more preferably 10 mg KOH / g or more, even more preferably 20 mg KOH / g or more, even more preferably 40 mg KOH / g or more, particularly preferably 50 mg KOH / g or more, and also preferably 200 mg KOH / g or less, more preferably 180 mg KOH / g or less, even more preferably 160 mg KOH / g or less, even more preferably 140 mg KOH / g or less, and particularly preferably 120 mg KOH / g or less. The above upper and lower limits can be combined arbitrarily. For example, the amine value of a polymer dispersant having a basic functional group is preferably 1 to 200 mg KOH / g, more preferably 10 to 180 mg KOH / g, even more preferably 20 to 160 mg KOH / g, even more preferably 40 to 140 mg KOH / g, and particularly preferably 50 to 120 mg KOH / g. If the amine value of the acrylic dispersant is above the lower limit, it tends to have good dispersibility. If the amine value of the acrylic dispersant is below the upper limit, it tends to have good compatibility with the (C) resin described later. Here, the amine value of the acrylic dispersant is expressed as the amount of base and the mass of equivalent KOH per gram of solid content excluding the solvent in the dispersant sample, and is measured by the following method: Accurately weigh 0.5 to 1.5 g of the dispersant sample into a 100 mL beaker and dissolve it in 50 mL of acetic acid. Using an automatic titrator equipped with a pH electrode, this solution is diluted to 0.1 mol / L HClO ４ The solution is neutralized by titration with acetic acid. The inflection point of the titration pH curve is used as the titration endpoint, and the amine value is determined by the following formula.

[0052] Amine value [mgKOH / g] = (561 × V) / (W × S) [where W: amount of dispersant sample weighed [g], V: titration volume at the titration endpoint [mL], S: solid content concentration of the dispersant sample [mass%]].

[0053] The weight-average molecular weight (Mw) of the acrylic dispersant is not particularly limited, but is preferably 1000 or more, more preferably 3000 or more, even more preferably 4000 or more, particularly preferably 5000 or more, and also preferably 50000 or less, more preferably 20000 or less, and even more preferably 15000 or less. The above upper and lower limits can be combined arbitrarily. For example, the weight-average molecular weight (Mw) of the acrylic dispersant is preferably 1000 to 50000, more preferably 3000 to 50000, even more preferably 4000 to 20000, and particularly preferably 5000 to 15000. If the weight-average molecular weight (Mw) of the acrylic dispersant is above the lower limit, the dispersibility tends to be good. If the weight-average molecular weight (Mw) of the acrylic dispersant is below the upper limit, viscosity changes tend to be less likely to occur.

[0054] The acrylic dispersant is preferably one that has a tertiary amino group and / or a quaternary ammonium group.

[0055] When an acrylic dispersant has a quaternary ammonium group as a functional group, the chemical structure of the repeating unit containing the quaternary ammonium group is not particularly limited. From the viewpoint of dispersibility, it is preferable that the acrylic dispersant has a repeating unit represented by the following general formula (1) (hereinafter also referred to as "repeating unit (1)").

[0056]

[0057] In formula (1), R ３１ ~R ３３ Each of these is independently a hydrogen atom, an optionally substituted alkyl group, an optionally substituted aryl group, or an optionally substituted aralkyl group, R ３１ ~R ３３ Two or more of these may be bonded together to form a ring structure. ３４ X is a hydrogen atom or a methyl group. ３１ is a divalent linking group, Y － It is an anti-anion.

[0058] R in equation (1) ３１ ~R ３３The alkyl group in which substituents may be linear or branched may also include cyclic structures such as cyclohexyl groups and cyclohexylmethyl groups. The number of carbon atoms in the alkyl group is not particularly limited, but is preferably 1 or more, preferably 10 or less, more preferably 6 or less, even more preferably 4 or less, and particularly preferably 2 or less. The above upper and lower limits can be combined arbitrarily. For example, the number of carbon atoms in the alkyl group is preferably 1 to 10, more preferably 1 to 6, even more preferably 1 to 4, and particularly preferably 1 to 2. Examples of alkyl groups include methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, and octyl groups, with methyl, ethyl, propyl, butyl, pentyl, and hexyl groups being preferred, methyl, ethyl, propyl, and butyl groups being more preferred, and methyl and ethyl groups being even more preferred.

[0059] R in equation (1) ３１ ~R ３３ The number of carbon atoms in the aryl group, which may have substituents, is not particularly limited, but is preferably 6 or more, preferably 16 or less, more preferably 12 or less, even more preferably 10 or less, and particularly preferably 8 or less. The above upper and lower limits can be arbitrarily combined. For example, the number of carbon atoms in the aryl group is preferably 6 to 16, more preferably 6 to 12, even more preferably 6 to 10, and particularly preferably 6 to 8. Examples of aryl groups include phenyl group, methylphenyl group, ethylphenyl group, dimethylphenyl group, diethylphenyl group, naphthyl group, and anthracenyl group, with phenyl group, methylphenyl group, ethylphenyl group, dimethylphenyl group, and diethylphenyl group being preferred, and phenyl group, methylphenyl group, and ethylphenyl group being more preferred.

[0060] R in equation (1) ３１ ~R ３３The number of carbon atoms in the aralkyl group, which may have substituents, is not particularly limited, but is preferably 7 or more, preferably 16 or less, more preferably 12 or less, even more preferably 10 or less, and particularly preferably 8 or less. The above upper and lower limits can be combined arbitrarily. For example, the number of carbon atoms in the aralkyl group is preferably 7 to 16, more preferably 7 to 12, even more preferably 7 to 10, and particularly preferably 7 to 8. Examples of aralkyl groups include phenylmethyl, phenylethyl, phenylpropyl, phenylbutyl, and phenylisopropyl groups, with phenylmethyl, phenylethyl, phenylpropyl, and phenylbutyl groups being preferred, and phenylmethyl and phenylethyl groups being more preferred.

[0061] From the perspective of variance, R ３１ ~R ３３ Preferably, each of them is independently an alkyl group or an aralkyl group, R ３１ ~R ３３ It is more preferable that each of them is independently a methyl group or a phenylmethyl group, R ３１ and R ３３ is a methyl group, R ３２ It is even more preferable that the group is a phenylmethyl group.

[0062] In equation (1), Y － For example, Cl － , Br － , I － , ClO ４ － BF ４ － ,CH ３ COO － , PF － These include: Aromatic dicarboxylic acid imide anions, aromatic sulfonic acid anions, aromatic phosphonic acid anions, and aromatic carboxylic acid anions described in International Publication No. 2018 / 079659; and alkyl sulfate anions and alkyl sulfonic acid anions described in International Publication No. 2019 / 107020; can also be suitably used.

[0063] When a polymeric dispersant has a tertiary amine as a functional group, it is preferable from the viewpoint of dispersibility and luminescence properties to have a repeating unit represented by the following general formula (2) (hereinafter sometimes referred to as "repeating unit (2)").

[0064]

[0065] In formula (2), R ３５ and R ３６ Each of these is independently a hydrogen atom, an optionally substituted alkyl group, an optionally substituted aryl group, or an optionally substituted aralkyl group, R ３５ and R ３６ They may combine with each other to form a ring structure. ３７ Z is a hydrogen atom or a methyl group. ３１ It is a divalent linking group.

[0066] R in equation (2) ３５ and R ３６ In this, the alkyl group which may have substituents is R of formula (1). ３１ ~R ３３ The example shown can preferably be adopted. R in formula (2) ３５ and R ３６ In this, the optionally substituted aryl group is R of formula (1). ３１ ~R ３３ The example shown can preferably be adopted. R in formula (2) ３５ and R ３６ In this, the optionally substituted aralkyl group is R of formula (1). ３１ ~R ３３ The examples provided can be preferably adopted.

[0067] From the perspective of dispersibility and luminescence characteristics, R ３５ and R ３６ Each of these groups is preferably an alkyl group which may have substituents, and more preferably a methyl group and an ethyl group.

[0068] R in equation (1) ３１ ~R ３３ and R in equation (2) ３５ and R ３６Examples of substituents that the alkyl group, aralkyl group, or aryl group in the compound may have include halogen atoms, alkoxy groups, benzoyl groups, and hydroxyl groups.

[0069] In equation (1), R ３１ ~R ３３ Examples of cyclic structures formed by the bonding of two or more of these include 5-7 membered nitrogen-containing heterocyclic monocyclic rings or fused rings formed by the fusion of two such rings. The nitrogen-containing heterocyclic rings are preferably non-aromatic, and saturated rings are even more preferable. Specifically, examples of nitrogen-containing heterocyclic rings include those listed below.

[0070]

[0071] In equation (I), R is R ３１ ~R ３３ It is one of the following. These cyclic structures may further have substituents.

[0072] In equation (2), R ３５ and R ３６ Examples of cyclic structures formed by the bonding of these elements include 5-7 membered nitrogen-containing heterocyclic monocyclic rings or fused rings formed by the fusion of two such rings. The nitrogen-containing heterocyclic rings are preferably non-aromatic, and saturated rings are even more preferable. Specifically, examples of nitrogen-containing heterocyclic rings include those listed below.

[0073]

[0074] These cyclic structures may further have substituents.

[0075] X in equation (1) ３１ and Z in equation (2) ３１ Examples include alkylene groups with 1 to 10 carbon atoms, arylene groups with 6 to 12 carbon atoms, and -CONH-R groups. ４３ - group, -COOR ４４ - Base (however, R ４３ and R ４４ Examples include a single bond, an alkylene group having 1 to 10 carbon atoms, or an ether group having 2 to 10 carbon atoms (alkyloxyalkyl group), preferably -COO-R ４４ -Base, more preferably-COO-C２ H ４ - It is the basis.

[0076] (B) From the viewpoint of dispersibility, the dispersant preferably has at least one of repeating unit (1) and repeating unit (2), more preferably has repeating unit (1), and even more preferably has repeating unit (1) and repeating unit (2) from the viewpoint of luminescence properties.

[0077] (B) The proportion of repeating unit (1) in the total repeating units of the dispersant is not particularly limited, but from the viewpoint of dispersibility, it is preferably 1 mol% or more, more preferably 3 mol% or more, even more preferably 5 mol% or more, particularly preferably 8 mol% or more, and also preferably 50 mol% or less, more preferably 30 mol% or less, even more preferably 20 mol% or less, and particularly preferably 15 mol% or less. The above upper and lower limits can be combined arbitrarily. For example, the proportion of repeating unit (1) is preferably 1 to 50 mol%, more preferably 3 to 30 mol%, even more preferably 5 to 20 mol%, and particularly preferably 8 to 15 mol%.

[0078] (B) The proportion of repeating units (2) in the total repeating units of the dispersant is not particularly limited, but from the viewpoint of dispersibility, it is preferably 5 mol% or more, more preferably 10 mol% or more, even more preferably 15 mol% or more, particularly preferably 20 mol% or more, and also preferably 60 mol% or less, more preferably 40 mol% or less, even more preferably 30 mol% or less, and particularly preferably 25 mol% or less. The above upper and lower limits can be combined arbitrarily. For example, the proportion of repeating units (2) is preferably 5 to 60 mol%, more preferably 10 to 40 mol%, even more preferably 15 to 30 mol%, and particularly preferably 20 to 25 mol%.

[0079] (B) From the viewpoint of improving the compatibility of the dispersant with (D) the solvent and (C) the resin, and improving dispersion stability, it is preferable that the dispersant (B) has repeating units represented by the following general formula (3) (hereinafter sometimes referred to as "repeating unit (3)").

[0080]

[0081] In formula (3), R ４０ R is an ethylene group or a propylene group, ４１ R is an alkyl group which may have substituents, ４２ is a hydrogen atom or a methyl group. n is an integer from 1 to 20.

[0082] R in equation (3) ４１ The alkyl group in which substituents may be linear or branched may also include cyclic structures such as cyclohexyl groups and cyclohexylmethyl groups. The number of carbon atoms in the alkyl group is not particularly limited, but is preferably 1 or more, more preferably 2 or more, preferably 10 or less, more preferably 6 or less, and still preferably 4 or less. The above upper and lower limits can be arbitrarily combined. For example, the number of carbon atoms in the alkyl group is preferably 1 to 10, more preferably 2 to 6, and still preferably 2 to 4. Examples of alkyl groups include methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, and octyl groups, with methyl, ethyl, propyl, butyl, pentyl, and hexyl groups being preferred, and methyl, ethyl, propyl, and butyl groups being more preferred.

[0083] In formula (3), n is preferably 1 or more, more preferably 2 or more, and more preferably 10 or less, and more preferably 5 or less, from the viewpoint of compatibility and dispersibility with (D) the solvent and (C) the resin. The above upper and lower limits can be combined arbitrarily. For example, n is preferably 1 to 10, and more preferably 2 to 5.

[0084] (B) The content of repeating unit (3) in the total repeating units of the dispersant is not particularly limited, but is preferably 1 mol% or more, more preferably 2 mol% or more, even more preferably 4 mol% or more, and also preferably 30 mol% or less, more preferably 20 mol% or less, and even more preferably 10 mol% or less. The above upper and lower limits can be combined arbitrarily. For example, the content of repeating unit (3) is preferably 1 to 30 mol%, more preferably 2 to 20 mol%, and even more preferably 4 to 10 mol%. If the content of repeating unit (3) is within the above range, it tends to be easier to achieve both compatibility with (D) solvent and (C) resin and dispersion stability.

[0085] (B) From the viewpoint of improving the compatibility of the dispersant with (D) the solvent and (C) the resin, and improving dispersion stability, it is preferable that the dispersant (B) has repeating units represented by the following general formula (4) (hereinafter sometimes referred to as "repeating unit (4)").

[0086]

[0087] In formula (4), R ３８ R is an optionally substituted alkyl group, an optionally substituted aryl group, or an optionally substituted aralkyl group. ３９ This is either a hydrogen atom or a methyl group.

[0088] R in equation (4) ３８The alkyl group in which substituents may be linear or branched may also include cyclic structures such as cyclohexyl groups and cyclohexylmethyl groups. The number of carbon atoms in the alkyl group is not particularly limited, but is preferably 1 or more, more preferably 2 or more, even more preferably 4 or more, preferably 10 or less, and even more preferably 8 or less. The above upper and lower limits can be arbitrarily combined. For example, the number of carbon atoms in the alkyl group is preferably 1 to 10, more preferably 2 to 8, and even more preferably 4 to 8. Examples of alkyl groups include methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, and 2-ethylhexyl groups, with methyl, ethyl, propyl, butyl, pentyl, hexyl, and 2-ethylhexyl groups being preferred, and methyl, ethyl, propyl, butyl, and 2-ethylhexyl groups being more preferred.

[0089] R in equation (4) ３８ The number of carbon atoms in the aryl group, which may have substituents, is not particularly limited, but is preferably 6 or more, preferably 16 or less, more preferably 12 or less, and even more preferably 8 or less. The above upper and lower limits can be combined arbitrarily. For example, the number of carbon atoms in the aryl group is preferably 6 to 16, more preferably 6 to 12, and even more preferably 6 to 8. Examples of aryl groups include phenyl, methylphenyl, ethylphenyl, dimethylphenyl, diethylphenyl, naphthyl, and anthracenyl groups, with phenyl, methylphenyl, ethylphenyl, dimethylphenyl, and diethylphenyl groups being preferred, and phenyl, methylphenyl, and ethylphenyl groups being more preferred.

[0090] R in equation (4) ３８In the case of an aralkyl group which may have a substituent, the number of carbon atoms is not particularly limited, but is preferably 7 or more, more preferably 16 or less, still more preferably 12 or less, and even more preferably 10 or less. The above upper and lower limits can be arbitrarily combined. For example, the number of carbon atoms of the aralkyl group is preferably 7 to 16, more preferably 7 to 12, and even more preferably 7 to 10. Examples of the aralkyl group include a phenylmethyl group, a phenylethyl group, a phenylpropyl group, a phenylbutyl group, and a phenylisopropyl group, and it is preferably a phenylmethyl group, a phenylethyl group, a phenylpropyl group, or a phenylbutyl group, and more preferably a phenylmethyl group or a phenylethyl group.

[0091] From the viewpoints of solvent compatibility and dispersion stability, R ３８ is preferably an alkyl group or an aralkyl group, and more preferably a methyl group, an ethyl group, a butyl group, a 2-ethylhexyl group or a phenylmethyl group. R ３８ Examples of the substituent that the alkyl group in R may have include a halogen atom and an alkoxy group. Examples of the substituent that the aryl group or aralkyl group in R may have include a linear alkyl group, a halogen atom, and an alkoxy group. The linear alkyl group represented by R ３８ includes both linear and branched chain forms.

[0092] (B) From the viewpoint of dispersibility, the content ratio of the repeating unit (4) in all the repeating units of the dispersant is preferably 30 mol% or more, more preferably 40 mol% or more, still more preferably 50 mol% or more, and preferably 80 mol% or less, and more preferably 70 mol% or less. The above upper and lower limits can be arbitrarily combined. For example, the content ratio of the repeating unit (4) is preferably 30 to 80 mol%, more preferably 40 to 80 mol%, and still more preferably 50 to 70 mol%.

[0093] (B) The dispersant may have repeating units other than repeating unit (1), repeating unit (2), repeating unit (3), and repeating unit (4). Examples of such repeating units include styrene monomers such as styrene and α-methylstyrene; (meth)acrylate monomers such as (meth)acrylate chloride; (meth)acrylamide monomers such as (meth)acrylamide and N-methylolacrylamide; and repeating units derived from monomers such as vinyl acetate, acrylonitrile, allyl glycidyl ether, glycidyl crotonic acid ether, and N-methacryloylmorpholine.

[0094] (B) The dispersant is preferably a block copolymer having an A block having repeating units (1) and (2), and a B block not having repeating units (1) and (2), from the viewpoint of further improving dispersibility. The block copolymer is preferably an A-B block copolymer or a B-A-B block copolymer. By introducing not only quaternary ammonium groups but also tertiary amino groups into the A block, the dispersing ability of the dispersant tends to be significantly improved. Furthermore, it is preferable that the B block has repeating units (3), and more preferably that it has repeating units (4).

[0095] In block A, repeating unit (1) and repeating unit (2) may be contained in either a random copolymerization or block copolymerization manner. Furthermore, two or more types of repeating unit (1) and repeating unit (2) may be contained in one block A, in which case each repeating unit may be contained in block A in either a random copolymerization or block copolymerization manner.

[0096] Repeating units other than repeating unit (1) and repeating unit (2) may be contained in block A, and examples of such repeating units include the repeating units derived from the (meth)acrylic acid ester monomers mentioned above. The content of repeating units other than repeating unit (1) and repeating unit (2) in block A is preferably 0 to 50 mol%, more preferably 0 to 20 mol%, but it is particularly preferable that such repeating units are not contained in block A.

[0097] Repeating units other than repeating units (3) and (4) may be contained in block B. Examples of such repeating units include styrene monomers such as styrene and α-methylstyrene; (meth)acrylate monomers such as (meth)acrylate chloride; (meth)acrylamide monomers such as (meth)acrylamide and N-methylolacrylamide; and repeating units derived from monomers such as vinyl acetate, acrylonitrile, allyl glycidyl ether, glycidyl crotonic acid ether, and N-methacryloylmorpholine. The content of repeating units other than repeating units (3) and (4) in block B is preferably 0 to 50 mol%, more preferably 0 to 20 mol%, but it is particularly preferable that such repeating units are not contained in block B. These (B) dispersants may be used individually or in combination of two or more.

[0098] Such (B) dispersants can be produced by known methods, but if the (B) dispersant is a block copolymer, for example, it can be produced by living polymerization of monomers into which each of the above repeating units is introduced. The methods exemplified above are examples of living polymerization methods.

[0099] (B) Examples of monomers used to introduce repeating unit (1) when producing the dispersant include (meth)acryloylaminopropyltrimethylammonium chloride, (meth)acryloyloxyethyltrimethylammonium chloride, (meth)acryloyloxyethyltriethylammonium chloride, (meth)acryloyloxyethyl(4-benzoylbenzyl)dimethylammonium bromide, (meth)acryloyloxyethylbenzyldimethylammonium chloride, and (meth)acryloyloxyethylbenzyldiethylammonium chloride. Examples of monomers to introduce repeating unit (2) include dimethylaminoethyl (meth)acrylate, diethylaminoethyl (meth)acrylate, dimethylaminopropyl (meth)acrylate, and diethylaminopropyl (meth)acrylate. Repeating unit (1) can also be introduced by polymerizing the monomer to which repeating unit (2) is introduced, and then reacting the polymer with a halogenated hydrocarbon compound such as benzyl chloride to partially quaternize the amino group.

[0100] Examples of monomers into which the repeating unit (3) is introduced include polyethylene glycol (n=1-5) methyl ether (meth)acrylate, polyethylene glycol (n=1-5) ethyl ether (meth)acrylate, polyethylene glycol (n=1-5) propyl ether (meth)acrylate, polypropylene glycol (n=1-5) methyl ether (meth)acrylate, polypropylene glycol (n=1-5) ethyl ether (meth)acrylate, and polypropylene glycol (n=1-5) propyl ether (meth)acrylate. Examples of monomers into which the repeating unit (4) is introduced include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, isopropyl (meth)acrylate, butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, phenyl (meth)acrylate, cyclohexyl (meth)acrylate, dicyclopentanyl (meth)acrylate, isobornyl (meth)acrylate, benzyl (meth)acrylate, and phenylethyl (meth)acrylate.

[0101] <(C) Resin> The pigment dispersion contains (C) resin. (C) resin is a component necessary for film formation, and the inclusion of (C) resin in the pigment dispersion enables the formation of a homogeneous coating film (F). (C) resin is a different component from (B) dispersant, and (B) dispersant is not included. In other words, the pigment dispersion contains (C) resin in addition to (B) dispersant. The (C) resin is not particularly limited as long as a homogeneous film can be obtained, but it is preferable that it prevents re-aggregation of pigment particles and improves the storage stability of the dispersion. Examples include thermoplastic resins, thermosetting resins, and active energy ray curable resins having ethylenically unsaturated double bonds.

[0102] Examples of thermoplastic resins include acrylic resins, butyral resins, styrene-maleic acid copolymers, chlorinated polyethylene, chlorinated polypropylene, polyvinyl chloride, vinyl chloride-vinyl acetate copolymers, polyvinyl acetate, polyurethane resins, polyester resins, vinyl resins, alkyd resins, polystyrene resins, polyamide resins, rubber resins, cyclorelated rubber resins, celluloses, polyethylene, polybutadiene, and polyimide resins. Thermoplastic resins may be used individually or in combination of two or more types.

[0103] Examples of thermosetting resins include epoxy resins, benzoguanamine resins, rosin-modified maleic acid resins, rosin-modified fumaric acid resins, melamine resins, urea resins, and phenolic resins. A single thermosetting resin may be used, or two or more may be used in combination.

[0104] (C) Specifically, resins containing carboxyl groups or hydroxyl groups are included, and more specifically, epoxy (meth)acrylate resins, isocyanurate skeleton-containing resins, acrylic copolymer resins (excluding epoxy (meth)acrylate resins), carboxyl group-containing epoxy resins (excluding epoxy (meth)acrylate resins), carboxyl group-containing urethane resins, novolac resins, and polyvinylphenol resins. Among these, the following resins are particularly suitable: ・(C1) Epoxy (meth)acrylate resin. ・(C2) Acrylic copolymer resin. (C) Resin may be used alone or in combination of two or more types.

[0105] (C1) Epoxy (Meth)acrylate Resins (C1) epoxy (meth)acrylate resins are resins obtained by reacting an epoxy compound (epoxy resin) with an α,β-unsaturated monocarboxylic acid and / or an α,β-unsaturated monocarboxylic acid ester having a carboxyl group in the ester portion, and then reacting the resulting hydroxyl group with a compound having two or more substituents that can react with hydroxyl groups, such as a polybasic acid and / or its anhydride. When adding the polybasic acid and / or its anhydride, a polyhydric alcohol may also be added at the same time. Resins obtained by reacting a compound having two or more substituents that can react with hydroxyl groups before reacting the polybasic acid and / or its anhydride with the hydroxyl group, and then reacting the polybasic acid and / or its anhydride, are also included in (C1) epoxy (meth)acrylate resins. Resins obtained by reacting the carboxyl group of the resin obtained in the above reaction with a compound having a further reactive functional group are also included in (C1) epoxy (meth)acrylate resins. Thus, (C1) epoxy (meth)acrylate resins do not substantially contain epoxy groups in terms of their chemical structure and are not limited to "(meth)acrylate," but since epoxy compounds (epoxy resins) are used as raw materials and "(meth)acrylate" is a representative example, they are named in this way according to convention.

[0106] Here, the term epoxy resin includes the raw material compound before the resin is formed by thermosetting, and the epoxy resin can be appropriately selected from known epoxy resins. Furthermore, the epoxy resin can be a compound obtained by reacting a phenolic compound with an epihalohydrin. The phenolic compound is preferably a compound having divalent or trivalent or more phenolic hydroxyl groups, and may be a monomer or a polymer. Suitable types of epoxy resins used as raw materials include, for example, cresol novolac type epoxy resin, phenol novolac type epoxy resin, bisphenol A type epoxy resin, bisphenol F type epoxy resin, trisphenolmethane type epoxy resin, biphenyl novolac type epoxy resin, naphthalene novolac type epoxy resin, epoxy resins that are reaction products of a polyaddition reaction product of dicyclopentadiene and phenol or cresol with an epihalohydrin, adamantyl group-containing epoxy resin, and fluorene type epoxy resin, with those having an aromatic ring in the main chain being more preferable.

[0107] Examples of epoxy resins include bisphenol A type epoxy resins (e.g., "jER (registered trademark, hereinafter the same) 828", "jER1001", "jER1002", "jER1004", etc. manufactured by Mitsubishi Chemical Corporation), epoxy resins obtained by the reaction of alcoholic hydroxyl groups of bisphenol A type epoxy resin with epichlorohydrin (e.g., "NER-1302" manufactured by Nippon Kayaku Co., Ltd. (epoxy equivalent 323, softening point 76°C)), and bisphenol F type resins (e.g., Mitsubishi Chemical Corporation) Epoxy resins obtained by the reaction of alcoholic hydroxyl groups of bisphenol F type epoxy resins with epichlorohydrin (e.g., "jER807", "EP-4001", "EP-4002", "EP-4004", etc. from Mikal Corporation), bisphenol S type epoxy resins, biphenyl glycidyl ethers (e.g., "YX-4000", from Mitsubishi Chemical Corporation), phenol novolac type epoxy resins Epoxy resins (for example, "EPPN-201" manufactured by Nippon Kayaku Co., Ltd., "EP-152" and "EP-154" manufactured by Mitsubishi Chemical Corporation, and "DEN-438" manufactured by Dow Chemical Corporation), (o,m,p-)cresol novolac type epoxy resins (for example, "EOCN (registered trademark, hereinafter the same)-102S", "EOCN-1020", and "EOCN-104S" manufactured by Nippon Kayaku Co., Ltd.), trisphenolmethane type epoxy resins (for example, "EPPN (registered trademark, hereinafter the same)-50" manufactured by Nippon Kayaku Co., Ltd.) 1), "EPPN-502", "EPPN-503", alicyclic epoxy resins ("Celoxide (registered trademark, hereinafter the same) 2021P", "Celoxide EHPE" manufactured by Daicel Corporation), epoxy resins obtained by glycidylating phenolic resins produced by the reaction of dicyclopentadiene and phenol (for example, "EXA-7200" manufactured by DIC Corporation, "NC-7300" manufactured by Nippon Kayaku Co., Ltd.), and epoxy resins represented by the following general formulas (C2α) to (C2δ) can be suitably used.Specifically, for example, as the epoxy resin represented by the following general formula (C2α), "XD-1000" manufactured by Nippon Kayaku Co., Ltd.; as the epoxy resin represented by the following general formula (C2β), "NC-3000" and "NC-3500" manufactured by Nippon Kayaku Co., Ltd.; as the epoxy resin represented by the following general formula (C2γ), "E-201" manufactured by Osaka Organic Chemical Industry Co., Ltd.; and as the epoxy resin represented by the following general formula (C2δ), "ESF-300" manufactured by Nippon Steel & Sumikin Chemical Co., Ltd. can be mentioned.

[0108]

[0109] In formula (C2α), a is an average value and represents a number from 0 to 10, and R １１１ each independently represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 8 carbon atoms, a cycloalkyl group having 3 to 10 carbon atoms, a phenyl group, a naphthyl group, or a biphenyl group. Note that the plurality of R １１１ present in one molecule may be the same or different from each other.

[0110]

[0111] In formula (C2β), b1 and b2 are average values and each independently represents a number from 0 to 10, and R １２１ each independently represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 8 carbon atoms, a cycloalkyl group having 3 to 10 carbon atoms, a phenyl group, a naphthyl group, or a biphenyl group. Note that the plurality of R １２１ present in one molecule may be the same or different from each other.

[0112]

[0113] In formula (C2γ), X represents a linking group represented by the following general formula (C2γ-1) or (C2γ-2). However, the molecular structure contains one or more adamantane structures. c represents 2 or 3.

[0114]

[0115] In formulas (C2γ-1) and (C2γ-2), R １３１ ~R １３４ and R １３５ ~R １３７Each of these independently represents an optionally substituted adamantyl group, a hydrogen atom, an optionally substituted C1-C12 alkyl group, or an optionally substituted phenyl group, and * represents a bond.

[0116]

[0117] In equation (C2δ), p and q each independently represent integers from 0 to 4, and R １４１ and R １４２ Each of these independently represents an alkyl group or halogen atom having 1 to 4 carbon atoms, R １４３ and R １４４ Each of the following independently represents an alkylene group having 1 to 4 carbon atoms, and x and y independently represent integers of 0 or greater.

[0118] Examples of α,β-unsaturated monocarboxylic acids or α,β-unsaturated monocarboxylic acid esters having a carboxyl group include (meth)acrylic acid, crotonic acid, o-, m- or p-vinylbenzoic acid, monocarboxylic acids such as α-haloalkyl, alkoxyl, halogen, nitro, and cyano-substituted derivatives of (meth)acrylic acid; 2-(meth)acryloyloxyethyl succinic acid, 2-(meth)acryloyloxyethyl adipic acid, 2-(meth)acryloyloxyethyl phthalic acid, 2-(meth)acryloyloxyethyl hexahydrophthalic acid, 2-(meth)acryloyloxyethyl maleic acid, 2-(meth)acryloyloxypropyl succinic acid, 2-(meth)acryloyloxypropyl adipic acid, 2-(meth)acryloyloxypropyl tetrahydrophthalic acid, 2-( Examples include meth)acryloyloxypropylphthalic acid, 2-(meth)acryloyloxypropylmaleic acid, 2-(meth)acryloyloxybutylsuccinic acid, 2-(meth)acryloyloxybutyladipic acid, 2-(meth)acryloyloxybutylhydrophthalic acid, 2-(meth)acryloyloxybutylphthalic acid, 2-(meth)acryloyloxybutylmaleic acid; monomers obtained by adding lactones such as ε-caprolactone, β-propiolactone, γ-butyrolactone, and δ-valerolactone to (meth)acrylic acid; monomers obtained by adding acids (anhydrides) such as (anhydride) succinic acid, (anhydride) phthalic acid, and (anhydride) maleic acid to hydroxyalkyl (meth)acrylates and pentaerythritol tri(meth)acrylates; and (meth)acrylic acid dimers.

[0119] Known methods can be used to add an α,β-unsaturated monocarboxylic acid or an α,β-unsaturated monocarboxylic acid ester having a carboxyl group to an epoxy resin. For example, an α,β-unsaturated monocarboxylic acid or an α,β-unsaturated monocarboxylic acid ester having a carboxyl group can be reacted with an epoxy resin at a temperature of 50 to 150°C in the presence of an esterification catalyst. Examples of esterification catalysts that can be used here include tertiary amines such as triethylamine, trimethylamine, benzyldimethylamine, and benzyldiethylamine, and quaternary ammonium salts such as tetramethylammonium chloride, tetraethylammonium chloride, and dodecyltrimethylammonium chloride.

[0120] Each component of the epoxy resin, α,β-unsaturated monocarboxylic acid or α,β-unsaturated monocarboxylic acid ester having a carboxyl group, and esterification catalyst may be selected individually or used in combination of two or more components. The amount of α,β-unsaturated monocarboxylic acid or α,β-unsaturated monocarboxylic acid ester having a carboxyl group used is preferably 0.5 to 1.2 equivalents, and more preferably 0.7 to 1.1 equivalents, per equivalent of epoxy groups in the epoxy resin. By setting the amount of α,β-unsaturated monocarboxylic acid or α,β-unsaturated monocarboxylic acid ester having a carboxyl group above the lower limit, insufficient introduction of unsaturated groups can be suppressed, and the subsequent reaction with polybasic acid and / or its anhydride tends to be sufficient. By setting the amount below the upper limit, the remaining unreacted α,β-unsaturated monocarboxylic acid or α,β-unsaturated monocarboxylic acid ester having a carboxyl group can be suppressed, and the curing properties tend to be good.

[0121] Examples of polybasic acids and / or their anhydrides include maleic acid, succinic acid, itaconic acid, phthalic acid, tetrahydrophthalic acid, hexahydrophthalic acid, pyromellitic acid, trimellitic acid, benzophenonetetracarboxylic acid, methylhexahydrophthalic acid, endomethylenetetrahydrophthalic acid, chlorendic acid, methyltetrahydrophthalic acid, biphenyltetracarboxylic acid, and their anhydrides. Among these, maleic acid, succinic acid, itaconic acid, phthalic acid, tetrahydrophthalic acid, hexahydrophthalic acid, pyromellitic acid, trimellitic acid, biphenyltetracarboxylic acid, and their anhydrides are preferred, and tetrahydrophthalic acid, trimellitic acid, biphenyltetracarboxylic acid, and their anhydrides are more preferred.

[0122] The addition reaction of polybasic acids and / or their anhydrides can be carried out using known methods. For example, the target product can be obtained by continuing the reaction under conditions similar to those used for the addition reaction of α,β-unsaturated monocarboxylic acids or α,β-unsaturated monocarboxylic acid esters having a carboxyl group to an epoxy resin. The amount of polybasic acid and / or its anhydride component added is preferably such that the acid value of the resulting carboxyl group-containing epoxy (meth)acrylate resin is 10 to 150 mg KOH / g, and more preferably 20 to 140 mg KOH / g. Keeping the addition within this range tends to improve the stability of the pigment dispersion.

[0123] During the addition reaction of a polybasic acid and / or its anhydride, a polyfunctional alcohol (polyhydric alcohol) such as trimethylolpropane, ditrimethylolpropane, pentaerythritol, dipentaerythritol, trimethylolethane, or 1,2,3-propanetriol may be added to introduce a highly branched structure. In this case, there are no particular restrictions on the mixing order of the polybasic acid and / or its anhydride and the polyfunctional alcohol. Upon heating, the polybasic acid and / or its anhydride undergo an addition reaction with any hydroxyl group present in the mixture of the epoxy resin, the reaction product of an α,β-unsaturated monocarboxylic acid or an α,β-unsaturated monocarboxylic acid ester having a carboxyl group, and the polyfunctional alcohol.

[0124] By using polyhydric alcohols, the molecular weight of (C1) epoxy (meth)acrylate resin can be increased, branching can be introduced into the molecule, and there is a tendency to be able to balance molecular weight and viscosity.

[0125] (C1) Examples of epoxy (meth)acrylate resins include, in addition to the resins mentioned above, the resin described in Korean Published Patent No. 10-2013-0022955.

[0126] The weight-average molecular weight (Mw) of the (C1) epoxy (meth)acrylate resin, measured by gel permeation chromatography (GPC) in terms of polystyrene, is preferably 1000 or more, more preferably 1500 or more, even more preferably 2000 or more, even more preferably 3000 or more, especially preferably 4000 or more, particularly preferably 5000 or more, and also preferably 30000 or less, more preferably 20000 or less, and even more preferably 15000 or less. The above upper and lower limits can be combined arbitrarily. For example, the weight-average molecular weight (Mw) of the (C1) epoxy (meth)acrylate resin is preferably 1000 to 30000, more preferably 1500 to 20000, even more preferably 2000 to 15000, even more preferably 3000 to 15000, especially preferably 4000 to 15000, and particularly preferably 5000 to 15000. (C1) If the weight-average molecular weight (Mw) of the epoxy (meth)acrylate resin is above the lower limit, the stability of the pigment dispersion tends to increase. (C1) If the weight-average molecular weight (Mw) of the epoxy (meth)acrylate resin is below the upper limit, (A) the particle size of the pigment tends to be easier to control.

[0127] (C1) As the epoxy (meth)acrylate resin, the following epoxy (meth)acrylate resins (C1-1) to (C1-3) are preferred. Among these, the epoxy (meth)acrylate resin (C1-1) is particularly preferred. ・Epoxy (meth)acrylate resin (C1-1): A resin having a structural unit represented by the following general formula (5). ・Epoxy (meth)acrylate resin (C1-2): A resin obtained by adding an α,β-unsaturated monocarboxylic acid or an α,β-unsaturated monocarboxylic acid ester having a carboxyl group to an epoxy resin, and further reacting it with a polybasic acid and / or its anhydride (except for epoxy (meth)acrylate resin (C1-1)). Epoxy (meth)acrylate resins (C1-3): Resins obtained by adding an α,β-unsaturated monocarboxylic acid or an α,β-unsaturated monocarboxylic acid ester having a carboxyl group to an epoxy resin, and further reacting it with a polyhydric alcohol and a polybasic acid and / or its anhydride (excluding epoxy (meth)acrylate resins (C1-1)). (C1) Epoxy (meth)acrylate resins may be used individually or in combination of two or more types.

[0128] <<Epoxy (meth)acrylate resin (C1-1)>> Epoxy (meth)acrylate resin (C1-1) is a resin having a structural unit represented by the following general formula (5).

[0129]

[0130] In formula (5), R １ R is a hydrogen atom or a methyl group, ２ Each of the following is independently an alkyl group having 1 to 4 carbon atoms, and L is an alkylene group having 2 to 6 carbon atoms, having at least a hydroxyl group or an ester group of a hydroxyl group and a polybasic acid as a substituent. * represents each bond.

[0131] Epoxy (meth)acrylate resins (C1-1) tend to exhibit high pigment dispersibility because they have a high affinity for (A) pigments and contain methylene groups in their main chain, giving them flexibility that can follow the pigments.

[0132] R in equation (5)１ R represents a hydrogen atom or a methyl group. From the viewpoint of curability, a hydrogen atom is preferred. ２ Each of these independently represents an alkyl group having 1 to 4 carbon atoms. ２ From the viewpoint of solvent solubility, the number of carbon atoms in the alkyl group is preferably 1 or more, preferably 3 or less, and more preferably 2 or less. The above upper and lower limits can be arbitrarily combined. For example, the number of carbon atoms in the alkyl group is preferably 1 to 3, and more preferably 1 to 2. The alkyl group may be linear or branched. Examples include methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, sec-butyl group, and tert-butyl group. From the viewpoint of dispersibility, the methyl group is preferred.

[0133] L represents an alkylene group having 2 to 6 carbon atoms, and has at least a hydroxyl group or an ester group of a hydroxyl group and a polybasic acid as a substituent. L preferably has 3 or more carbon atoms, more preferably 4 or more carbon atoms, preferably 6 or less, and more preferably 5 or less. The above upper and lower limits can be arbitrarily combined. For example, the number of carbon atoms in L may be 3 to 6, 3 to 5, 4 to 6, or 4 to 5. L has at least a hydroxyl group or an ester group of a hydroxyl group and a polybasic acid as a substituent, and may further be substituted with a methoxy group or an ethoxy group. Here, polybasic acid means the polybasic acid listed in the polybasic acid residues described later. Also, an ester group of a hydroxyl group and a polybasic acid means a group in which a hydroxyl group bonded to L forms an ester with a polybasic acid. The epoxy (meth)acrylate resin (C1-1) preferably has a structural unit of formula (5) that is described by the following general formula (6).

[0134]

[0135] In formula (6), A is a hydrogen atom or a polybasic acid residue, and R １ R is a hydrogen atom or a methyl group, ２ Each is independently an alkyl group having 1 to 4 carbon atoms. * represents each bond. R in formula (6) １ R in equation (5) is １This is the same as R in equation (6). ２ R in equation (5) is ２ It is the same as this.

[0136] In formula (6), A represents a hydrogen atom or a polybasic acid residue. A polybasic acid residue means a monovalent or divalent group obtained by removing one or two OH groups from a polybasic acid. Examples of the polybasic acids include maleic acid, succinic acid, itaconic acid, phthalic acid, tetrahydrophthalic acid, hexahydrophthalic acid, pyromellitic acid, trimellitic acid, benzophenonetetracarboxylic acid, methylhexahydrophthalic acid, endomethylenetetrahydrophthalic acid, chlorendic acid, methyltetrahydrophthalic acid, and biphenyltetracarboxylic acid. Among these, from the viewpoint of dispersion stability, maleic acid, succinic acid, itaconic acid, phthalic acid, tetrahydrophthalic acid, hexahydrophthalic acid, pyromellitic acid, trimellitic acid, and biphenyltetracarboxylic acid are preferred, and phthalic acid, succinic acid, trimellitic acid, and pyromellitic acid are more preferred. In particular, when the acid value is the same, trimellitic acid is preferred because the hydroxyl group, which has high solvent affinity, is relatively increased compared to the other basic acid residues.

[0137] The substructure represented by formula (5) contained in the epoxy (meth)acrylate resin (C1-1) may be one or more types, for example, a mixture of substructures in which A in formula (6) is a hydrogen atom and substructures in which A is a polybasic acid residue may be present. Examples of epoxy (meth)acrylate resins (C1-1) include structures represented by the following general formulas (C1-1-1) to (C1-1-8).

[0138]

[0139]

[0140]

[0141] As for the epoxy (meth)acrylate resin (C1-1), structures represented by formulas (C1-1-1), (C1-1-3), (C1-1-7), and (C1-1-8) are preferred from the viewpoint of dispersion stability.

[0142] The acid value of the epoxy (meth)acrylate resin (C1-1) is not particularly limited, but is preferably 10 mg KOH / g or more, more preferably 30 mg KOH / g or more, even more preferably 40 mg KOH / g or more, particularly preferably 50 mg KOH / g or more, and also preferably 200 mg KOH / g or less, more preferably 150 mg KOH / g or less, even more preferably 100 mg KOH / g or less, and particularly preferably 80 mg KOH / g or less. The above upper and lower limits can be arbitrarily combined. For example, the acid value of the epoxy (meth)acrylate resin (C1-1) is preferably 10 to 200 mg KOH / g, more preferably 30 to 150 mg KOH / g, even more preferably 40 to 100 mg KOH / g, and even more preferably 50 to 80 mg KOH / g.

[0143] The method for producing epoxy (meth)acrylate resin (C1-1) is not particularly limited, but for example, it can be obtained by adding (meth)acrylic acid to an epoxy resin represented by the following general formula (5-2), and then reacting it with a polybasic acid and / or its anhydride.

[0144]

[0145] R in equation (5-2) ２ And * are equivalent to equation (1).

[0146] Examples of epoxy resins represented by formula (5-2) include the following epoxy resins.

[0147]

[0148] In the above formula, m represents an integer between 2 and 8.

[0149] Known methods can be used to add (meth)acrylic acid to the epoxy resin represented by formula (5-2). For example, the epoxy resin and (meth)acrylic acid can be reacted at a temperature of 50 to 150°C in the presence of an esterification catalyst. Examples of esterification catalysts that can be used here include tertiary amines such as triethylamine, trimethylamine, benzyldimethylamine, and benzyldiethylamine, and quaternary ammonium salts such as tetramethylammonium chloride, tetraethylammonium chloride, and dodecyltrimethylammonium chloride.

[0150] Examples of polybasic acids and / or their anhydrides include the polybasic acids and / or their anhydrides mentioned above. Addition reactions of polybasic acids and / or their anhydrides can be carried out using known methods.

[0151] <<Epoxy (meth)acrylate resin (C1-2)>> Epoxy (meth)acrylate resin (C1-2) is a resin obtained by adding an α,β-unsaturated monocarboxylic acid or an α,β-unsaturated monocarboxylic acid ester having a carboxyl group to an epoxy resin, and then reacting it with a polybasic acid and / or its anhydride (excluding epoxy (meth)acrylate resin (C1-1)). As the epoxy (meth)acrylate resin (C1-2), for example, resins described in publications such as International Publication No. 2024 / 034637 can be used.

[0152] <<Epoxy (meth)acrylate resin (C1-3)>> Epoxy (meth)acrylate resin (C1-3) is a resin obtained by adding an α,β-unsaturated monocarboxylic acid or an α,β-unsaturated monocarboxylic acid ester having a carboxyl group to an epoxy resin, and further reacting it with a polyhydric alcohol and a polybasic acid and / or its anhydride (excluding epoxy (meth)acrylate resin (C1-1)). As the epoxy (meth)acrylate resin (C1-3), for example, resins described in publications such as International Publication No. 2024 / 034637 can be used.

[0153] ((C2) Acrylic Copolymer Resin) As the (C2) acrylic copolymer resin, for example, the one described in Japanese Patent Publication No. 2014-137466 can be preferably used. Examples of the (C2) acrylic copolymer resin include copolymers of an ethylenically unsaturated monomer having one or more carboxyl groups (hereinafter referred to as "unsaturated monomer (C2-1)") and other copolymerizable ethylenically unsaturated monomers (hereinafter referred to as "unsaturated monomer (C2-2)"). Examples of unsaturated monomers (C2-1) include unsaturated monocarboxylic acids such as (meth)acrylic acid, crotonic acid, α-chloroacrylic acid, and cinnamic acid; unsaturated dicarboxylic acids or their anhydrides such as maleic acid, maleic anhydride, fumaric acid, citraconic acid, citraconic anhydride, and mesaconic acid; mono[(meth)acryloyloxyalkyl] esters of divalent or higher polycarboxylic acids such as succinic acid mono[2-(meth)acryloyloxyethyl] and phthalic acid mono[2-(meth)acryloyloxyethyl]; mono(meth)acrylates of polymers having a carboxyl group and a hydroxyl group at both ends, such as ω-carboxypolycaprolactone mono(meth)acrylate; and p-vinylbenzoic acid. Unsaturated monomers (C2-1) may be used individually or in combination of two or more.

[0154] Examples of unsaturated monomers (C2-2) include N-substituted maleimides such as N-phenylmaleimide and N-cyclohexylmaleimide; aromatic vinyl compounds such as styrene, α-methylstyrene, p-hydroxystyrene, p-hydroxy-α-methylstyrene, p-vinylbenzylglycidyl ether and acenaphthylene; methyl (meth)acrylate, n-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, allyl ( Meth)acrylate, benzyl (meth)acrylate, polyethylene glycol (degree of polymerization 2-10) methyl ether (meth)acrylate, polypropylene glycol (degree of polymerization 2-10) methyl ether (meth)acrylate, polyethylene glycol (degree of polymerization 2-10) mono(meth)acrylate, polypropylene glycol (degree of polymerization 2-10) mono(meth)acrylate, cyclohexyl (meth)acrylate, isobornyl (meth)acrylate, tricyclo[5.2.1.0 ２，６ (meth)acrylic acid esters such as decane-8-yl (meth)acrylate, dicyclopentenyl (meth)acrylate, glycerol mono (meth)acrylate, 4-hydroxyphenyl (meth)acrylate, ethylene oxide-modified (meth)acrylate of paracumylphenol, glycidyl (meth)acrylate, 3,4-epoxycyclohexylmethyl (meth)acrylate, 3-[(meth)acryloyloxymethyl]oxetane, 3-[(meth)acryloyloxymethyl]-3-ethyloxetane; cyclohexyl vinyl ether, isobornyl vinyl ether, tricyclo[5.2.1.0 ２，６ Examples include vinyl ethers such as decane-8-yl vinyl ether, pentacyclopentadecanyl vinyl ether, and 3-(vinyloxymethyl)-3-ethyloxetane; and macromonomers having mono(meth)acryloyl groups at the ends of polymer molecular chains, such as polystyrene, polymethyl (meth)acrylate, poly-n-butyl (meth)acrylate, and polysiloxane. The unsaturated monomer (C2-2) may be used alone or in combination of two or more.

[0155] In copolymers of an unsaturated monomer (C2-1) and an unsaturated monomer (C2-2), the copolymerization ratio of the unsaturated monomer (C2-1) is preferably 5 to 50% by mass, and more preferably 10 to 40% by mass. By copolymerizing the unsaturated monomer (C2-1) within this range, it is possible to obtain a pigment dispersion with excellent storage stability.

[0156] Examples of copolymers of an unsaturated monomer (C2-1) and an unsaturated monomer (C2-2) include those disclosed in Japanese Patent Publication No. 7-140654, Japanese Patent Publication No. 8-259876, Japanese Patent Publication No. 10-31308, Japanese Patent Publication No. 10-300922, Japanese Patent Publication No. 11-174224, Japanese Patent Publication No. 11-258415, Japanese Patent Publication No. 2000-56118, and Japanese Patent Publication No. 2004-101728. Copolymers of an unsaturated monomer (C2-1) and an unsaturated monomer (C2-2) can be produced by known methods, but their structure, Mw, and Mw / Mn (where Mn is the number-average molecular weight) can also be controlled by methods disclosed, for example, in Japanese Patent Publication No. 2003-222717, Japanese Patent Publication No. 2006-259680, and International Publication No. 2007 / 029871. In addition, as the (C2) acrylic copolymer resin, resins described in International Publication No. 2016 / 194619 and International Publication No. 2017 / 154439 may also be used.

[0157] <(D) Solvent> The pigment dispersion contains (D) solvent. The inclusion of (D) solvent in the pigment dispersion allows (A) pigment to be dispersed or dissolved in (D) solvent, and also facilitates application. Water and organic solvents are preferred as (D) solvent. Among these, organic solvents are preferred from the viewpoint of dispersibility and application properties. One type of (D) solvent may be used alone, or two or more types may be used in combination.

[0158] In terms of organic solvents, it is preferable to select an organic solvent with a boiling point of 100 to 300°C from the viewpoint of coatability, and more preferably an organic solvent with a boiling point of 120 to 280°C. The boiling point refers to the boiling point at a pressure of 1013.25 hPa.

[0159] Examples of such organic solvents include the following: Glycol monoalkyl ethers such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol mono-n-butyl ether, propylene glycol-t-butyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol mono-n-butyl ether, methoxymethyl pentanol, dipropylene glycol monoethyl ether, dipropylene glycol monomethyl ether, 3-methoxybutanol, 3-methyl-3-methoxybutanol, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, and tripropylene glycol methyl ether; Glycol dialkyl ethers such as ethylene glycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol dipropyl ether, diethylene glycol dibutyl ether, and dipropylene glycol dimethyl ether; Glycol alkyl ether acetates such as ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol mono-n-butyl ether acetate, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol monopropyl ether acetate, propylene glycol monobutyl ether acetate, methoxybutyl acetate, 3-methoxybutyl acetate, methoxypentyl acetate, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, diethylene glycol mono-n-butyl ether acetate, dipropylene glycol monomethyl ether acetate, triethylene glycol monomethyl ether acetate, triethylene glycol monoethyl ether acetate, and 3-methyl-3-methoxybutyl acetate;Glycol diacetates such as ethylene glycol diacetate, 1,3-butylene glycol diacetate, and 1,6-hexylene glycol diacetate; alkyl acetates such as cyclohexanol acetate; ethers such as amyl ether, diethyl ether, dipropyl ether, diisopropyl ether, dibutyl ether, diamyl ether, ethyl isobutyl ether, and dihexyl ether; ketones such as acetone, methyl ethyl ketone, methyl amyl ketone, methyl isopropyl ketone, methyl isoamyl ketone, diisopropyl ketone, diisobutyl ketone, methyl isobutyl ketone, cyclohexanone, ethyl amyl ketone, methyl butyl ketone, methylhexyl ketone, methyl nonyl ketone, methoxymethylpentanone, and isophorone; Monohydric or polyhydric alcohols such as ethanol, propanol, butanol, hexanol, cyclohexanol, ethylene glycol, propylene glycol, butanediol, diethylene glycol, dipropylene glycol, triethylene glycol, methoxymethylpentanol, glycerin, and benzyl alcohol; aliphatic hydrocarbons such as n-pentane, n-octane, diisobutylene, n-hexane, hexene, isoprene, dipentene, and dodecane; alicyclic hydrocarbons such as cyclohexane, methylcyclohexane, methylcyclohexene, and bicyclohexyl; aromatic hydrocarbons such as benzene, toluene, xylene, and cumene; Chain-like or cyclic esters such as amyl formate, ethyl formate, ethyl acetate, butyl acetate, propyl acetate, amyl acetate, methyl isobutyrate, ethylene glycol acetate, ethyl propionate, propyl propionate, butyl butyrate, isobutyl butyrate, methyl isobutyrate, ethyl caprylate, butyl stearate, ethyl benzoate, methyl 3-ethoxypropionate, ethyl 3-ethoxypropionate, methyl 3-methoxypropionate, ethyl 3-methoxypropionate, propyl 3-methoxypropionate, butyl 3-methoxypropionate, γ-butyrolactone, etc.; alkoxycarboxylic acids such as 3-methoxypropionic acid and 3-ethoxypropionic acid; halogenated hydrocarbons such as butyl chloride and amyl chloride;Ether ketones such as methoxymethylpentanone; nitriles such as acetonitrile and benzonitrile.

[0160] Examples of commercially available organic solvents include mineral spirits, Balsol #2, Apco #18 solvent, Apco thinner, Socal solvent No. 1 and No. 2, Solvesso #150, Shell TS28 solvent, carbitol, ethyl carbitol, butyl carbitol, methyl cellosolve ("Cerosolve" is a registered trademark; the same applies hereinafter), ethyl cellosolve, ethyl cellosolve acetate, methyl cellosolve acetate, and Digrime (all trade names). Organic solvents may be used individually or in combination of two or more.

[0161] From the standpoint of having a good balance of applicability and surface tension, and the relatively high solubility of the constituent components in the pigment dispersion, glycol monoalkyl ethers, glycol alkyl ether acetates, and ketones are preferred as organic solvents, with glycol monoalkyl ethers and glycol alkyl ether acetates being more preferred.

[0162] <Optional Components> Optional components that may be included in the pigment dispersion include photopolymerizable monomers, photopolymerization initiators, organic carboxylic acids, organic carboxylic acid anhydrides, surfactants, thermal polymerization inhibitors, plasticizers, preservatives, surface protectants, adhesion enhancers, sensitizers, leveling agents, UV absorbers, dispersion aids, and dyes. Optional components may be used individually or in combination of two or more.

[0163] <Content ratio of each component in the pigment dispersion> (A) The pigment content is preferably 1% by mass or more, more preferably 5% by mass or more, even more preferably 10% by mass or more, and also preferably 30% by mass or less, more preferably 25% by mass or less, and even more preferably 20% by mass or less, based on the total mass of the pigment dispersion. The above upper and lower limits can be combined arbitrarily. For example, (A) The pigment content is preferably 1 to 30% by mass, more preferably 5 to 25% by mass, and even more preferably 10 to 20% by mass, based on the total mass of the pigment dispersion. (A) If the pigment content is above the lower limit, sufficient light shielding can be obtained in the visible light region. (A) If the pigment content is below the upper limit, sufficient transmittance can be obtained in the infrared region.

[0164] (A) The pigment content is preferably 20% by mass or more, more preferably 30% by mass or more, even more preferably 40% by mass or more, and preferably 75% by mass or less, more preferably 70% by mass or less, and even more preferably 65% ​​by mass or less, based on the total mass of the total solid content of the pigment dispersion. The above upper and lower limits can be combined arbitrarily. For example, (A) The pigment content is preferably 20 to 75% by mass, more preferably 30 to 70% by mass, and even more preferably 40 to 65% by mass, based on the total mass of the total solid content of the pigment dispersion. (A) If the pigment content is above the lower limit, good light shielding properties for visible light can be maintained. (A) If the pigment content is below the upper limit, good transmittance of infrared light can be maintained.

[0165] (B) The content of the dispersant is preferably 20 parts by mass or more, more preferably 30 parts by mass or more, even more preferably 40 parts by mass or more, and also preferably 300 parts by mass or less, more preferably 200 parts by mass or less, and even more preferably 150 parts by mass or less, based on 100 parts by mass of pigment (A). The above upper and lower limits can be combined arbitrarily. For example, the content of the dispersant (B) is preferably 20 to 300 parts by mass, more preferably 30 to 200 parts by mass, and even more preferably 40 to 150 parts by mass, based on the total mass of the pigment dispersion. In another embodiment, the content of the dispersant (B) is preferably 20 parts by mass or more, more preferably 30 parts by mass or more, even more preferably 33% by mass or more, even more preferably 40 parts by mass or more, and also preferably 300 parts by mass or less, more preferably 250 parts by mass or less, even more preferably 200 parts by mass or less, and even more preferably 150 parts by mass or less, based on 100 parts by mass of pigment (A). The above upper and lower limits can be combined arbitrarily. For example, the content of (B) dispersant is preferably 20 to 300 parts by mass, more preferably 30 to 300 parts by mass, even more preferably 33 to 250 parts by mass, even more preferably 33 to 200 parts by mass, and especially preferably 40 to 150 parts by mass, relative to the total mass of the pigment dispersion. If the content of (B) dispersant is above the lower limit, it is easy to improve dispersibility. If the content of (B) dispersant is below the upper limit, it is easy to improve the light-shielding properties of visible light.

[0166] (B) The content of the dispersant is preferably 5% by mass or more, more preferably 10% by mass or more, even more preferably 15% by mass or more, and preferably 70% by mass or less, more preferably 65% ​​by mass or less, and even more preferably 60% by mass or less, based on the total mass of the total solid content of the pigment dispersion. The above upper and lower limits can be combined arbitrarily. For example, the content of the dispersant is preferably 5 to 70% by mass, more preferably 10 to 65% by mass, and even more preferably 15 to 60% by mass, based on the total mass of the total solid content of the pigment dispersion. If the content of the dispersant is above the lower limit, sufficient dispersibility can be obtained. If the content of the dispersant is below the upper limit, sufficient light shielding of visible light can be obtained.

[0167] (C) The resin content is preferably 10 parts by mass or more, more preferably 20 parts by mass or more, even more preferably 30 parts by mass or more, and also preferably 300 parts by mass or less, more preferably 200 parts by mass or less, and even more preferably 100 parts by mass or less, based on 100 parts by mass of pigment (A). The above upper and lower limits can be combined arbitrarily. For example, the dispersant content is preferably 10 to 300 parts by mass, more preferably 20 to 200 parts by mass, and even more preferably 30 to 100 parts by mass, based on the total mass of the pigment dispersion. In another embodiment, the resin content is preferably 10 parts by mass or more, more preferably 20 parts by mass or more, even more preferably 30 parts by mass or more, even more preferably 40 parts by mass or more, especially preferably 45 parts by mass or more, particularly preferably 50 parts by mass or more, and also preferably 300 parts by mass or less, more preferably 200 parts by mass or less, and even more preferably 100 parts by mass or less, based on 100 parts by mass of pigment (A). The above upper and lower limits can be combined arbitrarily. For example, (B) the content of the dispersant is preferably 10 to 300 parts by mass, more preferably 20 to 300 parts by mass, even more preferably 30 to 300 parts by mass, even more preferably 40 to 300 parts by mass, especially preferably 45 to 200 parts by mass, and particularly preferably 50 to 100 parts by mass, relative to the total mass of the pigment dispersion. (C) If the content of the resin is above the above lower limit, sufficient dispersion stability can be obtained. (C) If the content of the resin is below the above upper limit, sufficient light-shielding properties for visible light can be obtained.

[0168] The content of (C) resin is preferably 5% by mass or more, more preferably 10% by mass or more, even more preferably 15% by mass or more, and preferably 60% by mass or less, more preferably 50% by mass or less, and even more preferably 40% by mass or less, based on the total mass of the total solid content of the pigment dispersion. The above upper and lower limits can be combined arbitrarily. For example, the content of (C) resin is preferably 5 to 60% by mass, more preferably 10 to 50% by mass, and even more preferably 15 to 40% by mass, based on the total mass of the total solid content of the pigment dispersion. If the content of (C) resin is above the lower limit above, sufficient dispersion stability can be obtained. If the content of (C) resin is below the upper limit above, sufficient light-shielding properties for visible light can be obtained.

[0169] The total content of (A) pigment, (B) dispersant, and (C) resin (hereinafter also referred to as "(A+B+C) amount") is preferably 15% by mass or more, more preferably 20% by mass or more, even more preferably 25% by mass or more, and preferably 45% by mass or less, more preferably 40% by mass or less, and even more preferably 35% by mass or less, based on the total mass of the pigment dispersion. The above upper and lower limits can be combined arbitrarily. For example, the (A+B+C) amount is preferably 15 to 45% by mass, more preferably 20 to 40% by mass, and even more preferably 25 to 35% by mass, based on the total mass of the pigment dispersion.

[0170] The amount of (A + B + C) is preferably 40% by mass or more, more preferably 50% by mass or more, even more preferably 60% by mass or more, and may be 100% by mass, based on the total mass of the total solid content of the pigment dispersion. For example, the amount of (A + B + C) is preferably 40 to 100% by mass, more preferably 50 to 100% by mass, and even more preferably 60 to 100% by mass, based on the total mass of the total solid content of the pigment dispersion.

[0171] The content of solvent (D) is preferably 55% by mass or more, more preferably 60% by mass or more, even more preferably 65% ​​by mass or more, and preferably 85% by mass or less, more preferably 80% by mass or less, and even more preferably 75% by mass or less, based on the total mass of the pigment dispersion. The above upper and lower limits can be combined arbitrarily. For example, the content of solvent (D) is preferably 55 to 85% by mass, more preferably 60 to 80% by mass, and even more preferably 65 to 75% by mass, based on the total mass of the pigment dispersion. In other words, the total solid content relative to the total mass of the pigment dispersion is preferably 15 to 45% by mass, more preferably 20 to 40% by mass, and even more preferably 25 to 35% by mass. If the content of component (D) is above the lower limit, an excessive increase in the viscosity of the pigment dispersion can be suppressed, and it can be handled easily. If the content of component (D) is below the upper limit, a coating film (F) of the desired thickness can be easily formed. In particular, when forming a coating film (F2), the viscosity is sometimes adjusted by adding additives such as resins to the pigment dispersion. However, if the viscosity of the pigment dispersion is too low, the amount of additives added tends to increase. When the amount of additives added increases, the proportion of (A) pigment in the formed coating film (F2) decreases. If the content of component (D) is below the above upper limit, an excessive decrease in the viscosity of the pigment dispersion can be suppressed, so the amount of additives added can be reduced, making it easier to form a coating film (F2) containing a sufficient amount of (A) pigment, and making it easier to maintain good visible light shielding and infrared light transmission. Note that (B) dispersants and (C) resins may be used in the production of pigment dispersions in a state that includes solvents (reaction solvents) used in their manufacturing process and solvents derived from the raw materials. The content of component (D) also includes solvents derived from (B) dispersants and (C) resins.

[0172] <Physical Properties of Pigment Dispersion> A coating film (F1) formed from a pigment dispersion, with a film thickness of 1.7 μm (hereinafter also referred to as "coating film (F1-1)"), preferably satisfies one or more of the following conditions (1) to (3), more preferably two or more, and even more preferably all of the following conditions (1) to (3). Condition (1): (Maximum transmittance of the pigment dispersion coating film) The maximum transmittance of light at wavelengths of 450 to 600 nm is 4% or less. Condition (2): (Minimum transmittance of the pigment dispersion coating film) The minimum transmittance of light at wavelengths of 850 to 1000 nm is 90% or more. Condition (3): (Transmission wavelength difference of the pigment dispersion coating film) The difference in wavelength (λ2 - λ1) between the maximum wavelength λ1 at which the transmittance of light is 20% and the minimum wavelength λ2 at which the transmittance of light is 90% is 50 nm or less.

[0173] In this invention, the coating film (F1-1) used to measure these transmittances is prepared by applying it to a glass substrate using a spin coater so that the film thickness after drying is 1.7 μm ± 0.1 μm, and then drying it on a hot plate at 100°C for 3 minutes.

[0174] Here, "maximum light transmittance at wavelengths of 450 to 600 nm" refers to the maximum value of light transmittance at wavelengths of 450 to 600 nm in the transmission spectrum measured by a spectrophotometer. "Minimum light transmittance at wavelengths of 850 to 1000 nm" refers to the minimum value of light transmittance at wavelengths of 850 to 1000 nm in the transmission spectrum measured by a spectrophotometer. "Maximum wavelength λ1 where light transmittance is 20%" refers to the maximum wavelength at which light transmittance is 20% in the transmission spectrum of wavelengths of 450 to 1000 nm measured by a spectrophotometer. "Minimum wavelength λ2 where light transmittance is 90%" refers to the minimum wavelength at which light transmittance is 90% in the transmission spectrum of wavelengths of 450 to 1000 nm measured by a spectrophotometer. Furthermore, in this invention, transmittance refers to transmittance relative to a glass substrate.

[0175] When the coating film (F1-1) satisfies condition (1), the transmission of visible light is further suppressed, resulting in more sufficient visible light shielding and higher blackness. In addition, the optical density (unit OD) per 1 μm of film thickness of the coating film (F1) tends to be 0.5 or higher. The unit OD of the coating film (F1) is preferably 0.5 to 4.0, more preferably 0.7 to 3.0, and even more preferably 1.0 to 2.0. When the coating film (F1-1) satisfies condition (2), the transmission of infrared light is further promoted, resulting in more sufficient infrared light transmittance. When the coating film (F1-1) satisfies condition (3), it can have a spectral shape that rises steeply from the visible region to the infrared region, so that visible light shielding and infrared light transmittance can be achieved at a higher level and in a good balance.

[0176] In condition (1), the maximum transmittance of light at wavelengths of 450 to 600 nm is 4% or less, preferably 3.5% or less, more preferably 3.0% or less, and even more preferably 2.5% or less. The lower limit of the maximum transmittance is not particularly limited and is, for example, 0%. In condition (2), the minimum transmittance of light at wavelengths of 850 to 1000 nm is 90.0% or more, preferably 90.5% or more, more preferably 91.0% or more, and even more preferably 91.5% or more. The upper limit of the minimum transmittance is not particularly limited and is, for example, 100%. In condition (3), the difference (λ2 - λ1) is 50 nm or less, preferably 48 nm or less, more preferably 46 nm or less, and even more preferably 44 nm or less. The lower limit of the difference (λ2 - λ1) is not particularly limited and is, for example, 0 nm.

[0177] The transmittance of the coating film (F1-1) can be adjusted by the composition of the film-forming components contained in the pigment dispersion, for example, (A) the composition and content of the pigment, and (B) the type and content of the dispersant. The transmittance of the coating film (F1-1) is measured using a spectrophotometer and the integrating sphere measurement method for a coating film (F1-1) with a thickness of 1.7 μm obtained by applying the pigment dispersion onto a substrate and drying it.

[0178] The method for producing the coating film (F1-1) is not particularly limited, but for example, the coating film (F1-1) can be obtained by applying the pigment dispersion to a substrate such that the film thickness after drying is 1.7 μm, and then drying it. The substrate is not particularly limited, but examples include the substrates exemplified later in the description of the coating film (F1). The method for applying the pigment dispersion is not particularly limited, but examples include the application methods exemplified later in the description of the coating film (F1). The drying method and drying conditions after application of the pigment dispersion are not particularly limited, but examples include the drying methods and drying conditions exemplified later in the description of the coating film (F1).

[0179] The viscosity of the pigment dispersion at 23°C is preferably 9 mPa·s or higher, more preferably 10 mPa·s or higher, even more preferably 15 mPa·s or higher, and also preferably 100 mPa·s or lower, more preferably 80 mPa·s or lower, and even more preferably 60 mPa·s or lower. The above upper and lower limits can be combined arbitrarily. For example, the viscosity of the pigment dispersion at 23°C is preferably 9 to 100 mPa·s, more preferably 10 to 80 mPa·s, and even more preferably 15 to 60 mPa·s, relative to the total mass of the pigment dispersion. If the viscosity of the pigment dispersion is above the above lower limit, a coating film (F) of the desired thickness can be easily formed. In addition, when forming the coating film (F2), the amount of additive added to the pigment dispersion can be reduced, making it easier to form a coating film (F2) containing a sufficient amount of (A) pigment, and making it easier to maintain good visible light shielding and infrared light transmittance. If the viscosity of the pigment dispersion is below the above upper limit, the handling of the pigment dispersion will be excellent.

[0180] The viscosity of the pigment dispersion can be adjusted by its composition, for example, (C) the type and amount of resin, and (D) the type and amount of component. The viscosity of the pigment dispersion is measured by adjusting the temperature of the pigment dispersion to 23°C and using a rotational viscometer with an E-type rotational viscometer at a rotational speed of 20 rpm.

[0181] <Method for producing a pigment dispersion> A pigment dispersion is obtained by mixing (A) a pigment, (B) a dispersant, (C) a resin, (D) a solvent, and optionally any other components. In other words, a pigment dispersion is a composition obtained by mixing (A) a pigment, (B) a dispersant, (C) a resin, (D) a solvent, and optionally any other components.

[0182] It is preferable to mix (A) pigment, (B) dispersant, (C) resin, (D) solvent, and optionally optional components, and then perform a dispersion treatment. That is, the method for producing a pigment dispersion preferably includes the following mixing step and dispersion treatment step. The pigment dispersion obtained through the following steps is a composition obtained by mixing (A) pigment, (B) dispersant, (C) resin, (D) solvent, and optionally optional components, and then performing a dispersion treatment on the resulting mixture. Mixing step: A step of preparing a mixture by mixing (A) pigment, (B) dispersant, (C) resin, (D) solvent, and optionally optional components. Dispersion treatment step: A step of performing a dispersion treatment on the mixture obtained in the mixing step. It is preferable that (A) pigment is a perylene-based pigment having absorption in the range of 400 to 650 nm. It is preferable that (A) pigment is a perylene-based pigment having a primary particle size of 20 to 150 nm, and more preferably a perylene-based pigment having a primary particle size of 20 to 100 nm. The primary particle size is determined by (A) dispersing the pigment in a solvent such as cyclohexanone, coating the resulting dispersion onto a colloidal film, and taking images with a scanning electron microscope (TEM). The primary particle size is then measured as the average value of the particle sizes of 1000 images obtained.

[0183] (Mixing process) The mixing process is a process of preparing a mixture by mixing A) pigment, (B) dispersant, (C) resin, (D) solvent, and optional components as needed. The method of mixing each component is not particularly limited, but for example, a method using a stirrer can be used.

[0184] (Dispersion Process) The dispersion process is a process of dispersing the mixture obtained in the mixing process. The method of dispersing the mixture is not particularly limited, but examples include methods using dispersion treatment equipment such as paint conditioners, sand grinders, ball mills, roll mills, stone mills, jet mills, homogenizers, and paint shakers. Dispersion using a jet mill, paint shaker, or ball mill is preferred. When dispersing, it is preferable to add beads with a particle size of about 0.1 to 8 mm to the mixture and disperse them. Among these, it is more preferable to use beads with a particle size of 0.4 mm or larger. For example, when using beads with a particle size of 0.3 mm or less, from the viewpoint of improving dispersibility, it is preferable to use a dispersion resin and include in an amount of 40 parts by mass or more per 100 parts by mass of pigment, or to include an amount of dispersant of 33 parts by mass or more per 100 parts by mass of pigment. Examples of beads include glass beads and zirconia beads. The temperature during the dispersion process is preferably 10 to 80°C, and more preferably 20 to 50°C. The appropriate time for dispersion processing varies depending on the composition of the mixed liquid and the size of the dispersion processing device, so it should be adjusted as needed.

[0185] <Applications of Pigment Dispersion> The pigment dispersion is suitable as an ink composition for forming infrared-transmitting filters. It is also suitable as a decorative ink composition for decorating peripheral areas such as the light-receiving parts of remote controls and the infrared receiver parts of mobile phones.

[0186] [Coating Film] The coating film (F) is a film formed using a pigment dispersion. The coating film (F) may be a film formed using only a pigment dispersion (coating film (F1)), or a film formed by adding additives to the pigment dispersion (coating film (F2)).

[0187] <Coating Film (F1)> The coating film (F1) is a film formed using only the pigment dispersion. That is, the coating film (F1) consists of film-forming components corresponding to the total solid content in the pigment dispersion, and contains at least the above-mentioned (A) pigment, (B) dispersant, and (C) resin. Since the pigment dispersion may contain optional components, the coating film (F1) may also contain optional components in addition to (A) pigment, (B) dispersant, and (C) resin. The content of each component in the coating film (F1) is the same as the content of each component relative to the total solid content in the pigment dispersion.

[0188] The film thickness of the coating (F1) is not particularly limited, but is preferably 0.5 μm or more, more preferably 1.0 μm or more, even more preferably 1.5 μm or more, and also preferably 6.0 μm or less, more preferably 5.5 μm or less, and even more preferably 5.0 μm or less. The above upper and lower limits can be combined arbitrarily. For example, the film thickness of the coating (F1) is preferably 0.5 to 6.0 μm, more preferably 1.0 to 5.5 μm, and even more preferably 1.5 to 5.0 μm.

[0189] The coating film (F1) is obtained by applying a pigment dispersion onto a substrate and drying it. The shape of the substrate is not particularly limited, but a film (including a sheet) is preferred. Examples of substrates include polyester resins such as polyethylene terephthalate, polyolefin resins such as polypropylene and polyethylene, thermoplastic resin sheets such as polycarbonate, polymethyl methacrylate, and polysulfone, thermosetting resin sheets such as epoxy resin, unsaturated polyester resin, and poly(meth)acrylic resin, and various types of glass. From the viewpoint of heat resistance, glass and heat-resistant resins are preferred. In addition, transparent electrodes such as ITO and IZO, or metal electrodes such as silver, gold, platinum, aluminum, and magnesium may be deposited on the surface of the substrate. Besides the substrates mentioned above, it is also possible to form the coating on a TFT array.

[0190] The substrate may be subjected to various treatments as needed to improve surface properties such as adhesion, including corona discharge treatment, ozone treatment, and thin-film formation treatment of various resins such as silane coupling agents and urethane resins. The thickness of the substrate is preferably in the range of 0.05 to 10 mm, more preferably in the range of 0.1 to 7 mm. When thin-film formation treatment of various resins is performed, the film thickness is preferably in the range of 0.01 to 10 μm, more preferably in the range of 0.05 to 5 μm.

[0191] The method for applying the pigment dispersion to the substrate is not particularly limited, but known methods include spraying, showering, dipping, rolling, spinning, curtaining, flowing, slitting, die printing, gravure printing, comma printing, dispenser printing, screen printing, and inkjet printing.

[0192] Drying after coating the substrate with the pigment dispersion is preferably done using a hot plate, an IR oven, or a convection oven. A vacuum drying method, in which drying is performed in a reduced-pressure chamber without raising the temperature, may also be used in combination. The drying temperature, drying time, and other conditions can be appropriately selected depending on the type of solvent (D) contained in the pigment dispersion, the performance of the dryer used, etc. For example, the drying conditions are preferably selected in the range of 15 seconds to 60 minutes at a temperature of 40 to 200°C, and more preferably in the range of 30 seconds to 30 minutes at a temperature of 50 to 180°C, depending on the type of solvent (D) and the performance of the dryer used.

[0193] If the pigment dispersion contains an alkali-soluble resin, the coating film (F1) may be manufactured by photolithography. For example, a coating film (F1) with a desired pattern shape can be easily obtained by performing exposure and development treatments after drying. The method of exposure and development treatments is not particularly limited, and known methods can be used.

[0194] The coating (F1) is likely to satisfy one or more of the above conditions (1) to (3). Furthermore, the optical density per 1 μm of film thickness of the coating (F1) is likely to be 0.5 or higher. The coating (F1) exhibits excellent shielding of visible light and transmittance of infrared light, and has a low haze value.

[0195] <Coating Film (F2)> The coating film (F2) is a film formed by adding additives to a pigment dispersion. That is, the coating film (F2) consists of film-forming components corresponding to the total solid content in the pigment dispersion and additives, and contains the above-mentioned (A) pigment, (B) dispersant, (C) resin, and additives. Since the pigment dispersion may contain optional components, the coating film (F2) may contain additional optional components in addition to (A) pigment, (B) dispersant, (C) resin, and additives.

[0196] The additive is a resin. In particular, it is an externally added resin. Resins that are added to a pigment dispersion afterwards are also called "externally added resins." The mixture of the pigment dispersion and the additive is also called a "composition" or "colored composition."

[0197] Examples of externally added resins include polycarbonate resin, acrylic resin, epoxy resin, and polyester resin. Alternatively, the above-mentioned (C) resin may be used as the externally added resin. When (C) resin is used as the externally added resin, the externally added resin and the (C) resin contained in the pigment dispersion may be the same or different. One embodiment of the composition is a composition containing one or more resins (externally added resins) selected from polycarbonate resin, acrylic resin, and epoxy resin, and a pigment dispersion.

[0198] The amount of additive added is preferably 0.5 parts by mass or more, more preferably 10 parts by mass or less, more preferably 8 parts by mass or less, and even more preferably 5 parts by mass or less, per 100 parts by mass of the total solid content of the pigment dispersion. The above upper and lower limits can be combined arbitrarily. For example, the amount of additive added is preferably 0.5 to 10 parts by mass, more preferably 0.5 to 8 parts by mass, and even more preferably 0.5 to 5 parts by mass, per 100 parts by mass of the total solid content of the pigment dispersion. If the amount of additive added is above the above lower limit, the effect of the additive will be exerted. If the amount of additive added is below the above upper limit, a coating film (F2) containing a sufficient amount of (A) pigment will be more easily formed, and it will be easier to maintain good visible light shielding and infrared light transmittance. In another embodiment, the amount of additive added is preferably 0.5 parts by mass or more, more preferably 20 parts by mass or less, and even more preferably 15 parts by mass or less, per 100 parts by mass of the total solid content of the pigment dispersion. The above upper and lower limits can be combined arbitrarily. For example, the amount of additive added is preferably 0.5 to 20 parts by mass, more preferably 0.5 to 15 parts by mass, per 100 parts by mass of the total solid content of the pigment dispersion. The amount of additive added is preferably 1 part by mass or more, preferably 40 parts by mass or less, more preferably 30 parts by mass or less, and even more preferably 20 parts by mass or less, per 100 parts by mass of (A) pigment. The above upper and lower limits can be combined arbitrarily. For example, the amount of additive added is preferably 1 to 40 parts by mass, more preferably 1 to 30 parts by mass, and even more preferably 1 to 20 parts by mass, per 100 parts by mass of (A) pigment. The amount of additive added is preferably 0.5 parts by mass or more, preferably 20 parts by mass or less, more preferably 15 parts by mass or less, and even more preferably 10 parts by mass or less, per 100 parts by mass of (B) dispersant. The above upper and lower limits can be combined arbitrarily. For example, the amount of additive added is preferably 0.5 to 20 parts by mass, more preferably 0.5 to 15 parts by mass, and even more preferably 1 to 10 parts by mass, per 100 parts by mass of (B) dispersant. The amount of additive added is preferably 0.5 parts by mass or more, more preferably 20 parts by mass or less, more preferably 15 parts by mass or less, and even more preferably 10 parts by mass or less, per 100 parts by mass of (C) resin. The above upper and lower limits can be combined arbitrarily.For example, the amount of additive added is preferably 0.5 to 20 parts by mass, more preferably 0.5 to 15 parts by mass, and even more preferably 1 to 10 parts by mass, per 100 parts by mass of resin (C).

[0199] The total solid content of the composition is preferably 20% by mass or more, more preferably 25% by mass or more, even more preferably 30% by mass or more, and preferably 70% by mass or less, more preferably 65% ​​by mass or less, and even more preferably 60% by mass or less, based on the total mass of the composition. The above upper and lower limits can be combined arbitrarily. For example, the total solid content of the composition is preferably 20 to 70% by mass, more preferably 25 to 65% by mass, and even more preferably 30 to 60% by mass, based on the total mass of the composition. If the total solid content of the composition is above the lower limit, a coating film (F2) of the desired thickness can be easily formed. If the total solid content of the composition is below the upper limit, the coating properties on the substrate are excellent.

[0200] The content of pigment (A) in the coating film (F2) is preferably 1% by mass or more, more preferably 3% by mass or more, even more preferably 5% by mass or more, and also preferably 50% by mass or less, more preferably 40% by mass or less, and even more preferably 30% by mass or less, based on the total mass of the coating film (F2). The above upper and lower limits can be combined arbitrarily. For example, the content of pigment (A) is preferably 1 to 50% by mass, more preferably 3 to 40% by mass, and even more preferably 5 to 30% by mass, based on the total mass of the coating film (F2). If the content of pigment (A) is above the lower limit, the light-shielding properties of visible light can be maintained more effectively. If the content of pigment (A) is below the upper limit, the transmittance of infrared light can be maintained more effectively.

[0201] The content of the (B) dispersant in the coating film (F2) is preferably 1% by mass or more, more preferably 3% by mass or more, even more preferably 5% by mass or more, and preferably 40% by mass or less, more preferably 35% by mass or less, and even more preferably 30% by mass or less, based on the total mass of the coating film (F2). The above upper and lower limits can be combined arbitrarily. For example, the content of the (B) dispersant is preferably 1 to 40% by mass, more preferably 3 to 35% by mass, and even more preferably 5 to 30% by mass, based on the total mass of the coating film (F2). If the content of the (B) dispersant is above the lower limit, aggregation of the (A) pigment can be prevented. If the content of the (B) dispersant is below the upper limit, the light-shielding properties of visible light can be maintained more effectively.

[0202] The content of resin components in the coating film (F2), that is, the total content of (C) resin and externally added resin as an additive, is preferably 5% by mass or more, more preferably 10% by mass or more, even more preferably 20% by mass or more, and also preferably 80% by mass or less, more preferably 70% by mass or less, and even more preferably 60% by mass or less, based on the total mass of the coating film (F2). The above upper and lower limits can be combined arbitrarily. For example, the content of resin components is preferably 5 to 80% by mass, more preferably 10 to 70% by mass, and even more preferably 20 to 60% by mass, based on the total mass of the coating film (F2). If the content of resin components is above the lower limit, the light-shielding properties of visible light are superior. If the content of resin components is below the upper limit, the film-forming properties are superior. In another embodiment, it is preferably 100% by mass or less, and more preferably 90% by mass or less. This upper limit can be combined arbitrarily with the lower limit.

[0203] The thickness of the coating film (F2) is not particularly limited, but for example, it is preferably 0.5 μm or more, more preferably 1.0 μm or more, even more preferably 1.5 μm or more, and also preferably 50 μm or less, more preferably 40 μm or less, and even more preferably 30 μm or less. The above upper and lower limits can be combined arbitrarily. For example, the thickness of the coating film (F2) is preferably 0.5 to 50 μm, more preferably 1.0 to 40 μm, and even more preferably 1.5 to 30 μm.

[0204] The coating film (F2) is obtained by applying the composition onto a substrate and drying it. Examples of substrates include those exemplified in the description of the coating film (F1). The method for applying the composition is the same as that for applying the pigment dispersion. The drying method and conditions after applying the composition onto the substrate are the same as those for producing the coating film (F1). The coating film (F2) may also be produced by photolithography.

[0205] Since the coating film (F2) is formed using a pigment dispersion, it is likely to satisfy one or more of the above conditions (1) to (3). In addition, the optical density per 1 μm of film thickness of the coating film (F2) is likely to be 0.5 or higher. The coating film (F2) has excellent shielding properties for visible light and transmittance for infrared light, and has a low haze value.

[0206] <Applications> The coating (F) can be used as a component of an infrared transmission filter or as a decorative film. When the coating (F) is used as a decorative film, for example, it can be used to decorate the surrounding areas of the light-receiving part of a remote control or the infrared-receiving part of a mobile phone, or to decorate an undecorated infrared transmission filter used in these light-receiving parts or infrared-receiving parts. An example of an undecorated infrared transmission filter is an infrared transmission filter that exhibits black color. Since the coating (F) has excellent visible light shielding properties and is jet black, even when decorating an undecorated infrared transmission filter or its surrounding area, the boundary is difficult to see, and excellent design can be achieved.

[0207] [Infrared Transmission Filter] The infrared transmission filter comprises a coating film (F) formed using a pigment dispersion. The coating film (F) may be coating film (F1) or coating film (F2). The infrared transmission filter may consist only of the coating film (F), or it may include other components in addition to the coating film (F).

[0208] Other components include, for example, the substrate exemplified earlier in the description of the coating (F), films other than the coating (F) (hereinafter also referred to as "other films"), glass, polycarbonate, acrylic resin, polypropylene, polyethylene, polyethylene terephthalate (PET), and vinyl chloride resin. When the infrared transmission filter includes other films, the coating (F) can be arranged to be the outermost layer, i.e., the viewing side.

[0209] Infrared transmission filters can be used in devices such as infrared sensors and infrared cameras.

[0210] [Infrared Sensors, Infrared Cameras] Infrared sensors and infrared cameras are each equipped with an infrared transmission filter. Examples of infrared sensors include those for iris recognition, distance measurement, proximity, gesture, motion, TOF (Time-of-Flight) sensors, vein sensors, blood vessel visualization, blood oxygen concentration measurement, sebum amount measurement, fluorescent labeling, and surveillance cameras. Examples of infrared cameras include near-infrared cameras, surveillance cameras, in-vehicle cameras, medical cameras, inspection cameras, and analytical cameras. The configuration of infrared sensors and infrared cameras is not particularly limited as long as they are equipped with an infrared transmission filter and function as infrared sensors and infrared cameras.

[0211] The present invention will be described in more detail below with reference to examples and comparative examples, but the present invention is not limited to the following examples unless it exceeds the gist of the invention. The components of the pigment dispersions used in the following examples and comparative examples, and the methods for evaluating them, are as follows.

[0212] [(A) Pigments] The following compounds were used as (A) pigments. ・A-1: C.I. Pigment Violet 29 (D15=75nm, D50=80nm, D85=85nm). ・A-2: C.I. Pigment Violet 29 (manufactured by DIC Corporation, trade name "Paliogen Red Violet K 5411", D15=239nm, D50=266nm, D85=338nm). ・A-3: C.I. Pigment Violet 23 (manufactured by Sanyo Shikkei Co., Ltd., D15=120nm, D50=142nm, D85=181nm). ・A-4: C.I. Pigment Blue 15:6 (manufactured by Dainichi Seika Kogyo Co., Ltd., D15 = 78 nm, D50 = 80 nm, D85 = 85 nm). A-5: C. I. Pigment Yellow 139 (manufactured by Beubach, D15 = 91 nm, D50 = 96 nm, D85 = 105 nm). D15, D50, and D85 listed here are the particle sizes measured by the method described below for each pigment, after preparing a single-color pigment dispersion containing 33 parts by mass of dispersant B-2, 33 parts by mass of resin C-1, and 664 parts by mass of solvent D-1 per 100 parts by mass of pigment. It is presumed that the primary particle size of pigment A-1 measured by the method described above is 80 nm or less.

[0213] [(B) Dispersant] The following compound was used as the dispersant (B): B-1: A methacrylic acid-based AB block copolymer consisting of a solvent-philic A block and a nitrogen atom-containing functional group B block (manufactured by Bic Chemie, trade name "BYK-LPN6919"). BYK-LPN6919 has repeating units of the following formulas (2-1) and (3-1), and does not have repeating units of the following formula (1-1). The amine value of BYK-LPN6919 is 120 mgKOH / g, and the acid value is 1 mgKOH / g or less. The content of the following formulas (2-1) and (3-1) in the total repeating units of BYK-LPN6919 is 33.3 mol% and 6.7 mol%, respectively.

[0214]

[0215] ・B-2: A methacrylic AB block copolymer consisting of a solubility A block and a nitrogen atom-containing functional group B block (manufactured by Bic Chemie, trade name "BYK-LPN21116"). BYK-LPN21116 has repeating units of the above formulas (1-1), (2-1), and (3-1). The amine value of BYK-LPN21116 is 70 mgKOH / g, and the acid value is 1 mgKOH / g or less. The content percentages of the following formulas (1-1), (2-1), and (3-1) in the total repeating units of BYK-LPN21116 are 11.1 mol%, 22.2 mol%, and 6.7 mol%, respectively.

[0216] [(C) Resin] The following compounds were used as (C) resin. • C-1: Resin obtained by the following synthesis method.

[0217] <Synthesis of C-1> 100 parts by mass of an epoxy compound having repeating units represented by the following formula (epoxy equivalent 273), 26.42 parts by mass of acrylic acid, 2.53 parts by mass of triphenylphosphine, 0.0632 parts by mass of 4-methoxyphenol, and 84.28 parts by mass of propylene glycol monomethyl ether acetate were charged into a reaction vessel and stirred. Next, 22.8 parts by mass of trimellitic anhydride and 48.9 parts by mass of propylene glycol monomethyl ether acetate were further added and the reaction was carried out. The weight-average molecular weight Mw of the resin thus obtained, measured by GPC, was 1668, and the acid value was 96.3 mgKOH / g. The obtained resin corresponds to an epoxy (meth)acrylate resin (C1-1) and corresponds to the structure represented by the above formula (C1-1-1).

[0218]

[0219] [(D) Solvent] The following organic solvents and water were used as (D) solvents: • D-1: PGMEA (propylene glycol monomethyl ether acetate). • D-2: Isophorone. • D-3: PGEE (propylene glycol monoethyl ether).

[0220] [Measurement and Evaluation] <Measurement of Particle Size> After allowing the pigment dispersion to stand at room temperature (23°C) for one week, the pigment (A) in the dispersion was diluted with PGMEA so that its concentration was 100 ppm by mass. The resulting diluted solution was measured at room temperature using a dynamic light scattering particle size distribution analyzer (Otsuka Electronics Co., Ltd., product name "Concentrated Particle Size Analyzer FPAR-1000"), and the particle sizes corresponding to 15%, 50%, and 85% of the cumulative particle size distribution based on volume were determined.

[0221] <Viscosity Measurement> After preparing the pigment dispersion, the viscosity of the pigment dispersion was measured using an E-type rotational viscometer (BROOKFIELD, product name "DV-II+Pro") at a temperature of 23°C and a rotational speed of 10 rpm.

[0222] <Measurement of Optical Density per Unit Film Thickness (in OD)> The optical density per unit film thickness was measured using the following procedure. First, a pigment dispersion was applied to a 7 cm x 7 cm glass substrate (AGC Corporation, product name "AN100") using a spin coater, and dried on a hot plate at 100°C for 3 minutes to prepare a test specimen with a coating film (F1) of 1.7 μm thickness formed on the glass substrate. The spin coater conditions were as follows: 1st step: rotated at 500 rpm for 2 seconds; 2nd step: adjusted for each sample between 1000 and 3500 rpm to achieve a film thickness of 1.7 μm and rotated for 10 seconds; 3rd step: rotated by inertia for 2 seconds and then stopped. The optical density (OD) of the coating film (F1) of the obtained test specimen was measured using a transmission densitometer (X-Rite Corporation, product name "361T(V)"). The film thickness of the coating (F1) was measured separately using a scanning white light interference microscope (Hitachi High-Technologies Corporation, product name "VS1530"). From the optical density (OD) and film thickness, the optical density (in OD) per unit film thickness (1.0 μm) was calculated. Note that OD is a value that indicates the light-shielding ability, and a higher value indicates higher light-shielding ability.

[0223] <Measurement of Transmittance> Test specimens were prepared in the same manner as for the measurement of OD units. The transmittance of the coating film (F1) of the obtained test specimens at wavelengths of 220 to 1400 nm was measured using a UV-Vis spectrophotometer (Shimadzu Corporation, product name "UV-2600i") equipped with an integrating sphere attachment (Shimadzu Corporation, product name "ISR-2600 Plus"). The measurement conditions were a medium scan speed, a slit width of 5 nm, and a data interval of 1 nm. The maximum transmittance of light at wavelengths of 450 to 600 nm, the minimum transmittance of light at wavelengths of 850 to 1000 nm, the maximum wavelength λ1 at which the transmittance of light is 20%, and the minimum wavelength λ2 at which the transmittance of light is 90% were determined. The transmittance values ​​shown are relative to the glass substrate.

[0224] <Evaluation of Haze Value> Test specimens were prepared in the same manner as for the measurement of OD units. The diffuse transmittance and total transmittance of the coating film (F1) of the obtained test specimens at a wavelength of 940 nm were measured in accordance with JIS K 7136:2000 using a UV-Vis spectrophotometer (Shimadzu Corporation, product name "UV-2600i") equipped with an integrating sphere attachment (Shimadzu Corporation, product name "ISR-2600 Plus"), and the haze value at a wavelength of 940 nm was determined. The haze value is an indicator of contrast, and a lower value indicates higher contrast.

[0225] <Evaluation of Surface Roughness> Test specimens were prepared in the same manner as for measurement in units of OD. The root mean square height (Sq) of a 10 μm × 10 μm area of ​​the coating film (F1) of the obtained test specimen was measured using a scanning white light interference microscope (Hitachi High-Technologies Corporation, product name "VS1530"). The measurement mode was set to Focus mode, the objective lens magnification was 50x, and the center wavelength of the measurement light was 520 nm. Sq is an index of surface roughness, calculated by dividing the volume of the area enclosed by the curved surface and the average surface by the measured area. A lower value indicates lower surface roughness, i.e., higher smoothness.

[0226] [Examples 1-8, Comparative Examples 1-9] The (A) pigment, (B) dispersant, (C) resin, and (D) solvent listed in Tables 1 and 2 were mixed in the mass ratios listed in Tables 1 and 2. This mixture was dispersed using a paint shaker at a temperature of 25-45°C for 6 hours. For Examples 1-8 and Comparative Examples 1-5, 0.5 mmφ zirconia beads were used, and for Comparative Examples 6-9, 0.3 mmφ zirconia beads were used, with 2.5 times the mass of the mixture added. After dispersion, the beads and dispersion were separated by a filter to prepare the pigment dispersion. Note that the amount of (D) solvent listed in Tables 1 and 2 is the amount of organic solvent or water when the amount of (A) pigment is set to 1, and this includes the amounts of (B) dispersant and (C) resin-derived solvents. Also, blank spaces in Tables 1 and 2 mean that the component is not included (amount 0 parts by mass). The particle size of pigment (A) in the obtained pigment dispersion and the viscosity of the pigment dispersion were measured. Furthermore, a coating film (F1) was formed using the pigment dispersion, and the unit OD and transmittance were measured, while the haze value and surface roughness were evaluated. These results are shown in Tables 1 and 2.

[0227]

[0228]

[0229] As is clear from the results in Table 1, the pigment dispersions obtained in Examples 1 to 8 had a moderate viscosity, excellent visible light shielding and infrared light transmittance, low haze values, and formed a smooth coating film (F1). On the other hand, the coating films (F1) formed from the pigment dispersions obtained in Comparative Examples 1 to 9 were inferior in either visible light shielding, infrared light transmittance, or haze value.

Claims

1. A pigment dispersion containing (A) a pigment, (B) a dispersant, (C) a resin, and (D) a solvent, wherein the (A) pigment contains C.I. Pigment Violet 29, and after the pigment dispersion is left to stand at room temperature (20-30°C) for 24 hours or more, the concentration of the pigment (A) in the pigment dispersion is adjusted to 100 ppm by mass, and the median diameter (D50) of the pigment (A) observed by dynamic light scattering is 110 nm or less.

2. The pigment dispersion according to claim 1, wherein, after the pigment dispersion is left to stand at room temperature (20-30°C) for 24 hours or more, the concentration of pigment (A) in the pigment dispersion is adjusted to 100 ppm by mass, and the difference between the particle size of pigment (A) (D85) and the particle size of pigment (A) (D15) observed by dynamic light scattering is 50 nm or less.

3. The pigment dispersion according to claim 1, wherein the content of the resin (C) is 40 to 300 parts by mass per 100 parts by mass of the pigment (A).

4. The pigment dispersion according to claim 1, wherein a coating film with a thickness of 1.7 μm formed from the pigment dispersion satisfies the following condition (1): The maximum transmittance of light at wavelengths of 450 to 600 nm is 4% or less.

5. The pigment dispersion according to claim 1, wherein a coating film with a thickness of 1.7 μm formed from the pigment dispersion satisfies the following condition (2): The minimum transmittance of light at wavelengths of 850 to 1000 nm is 90% or more.

6. The pigment dispersion according to claim 1, wherein a coating film with a thickness of 1.7 μm formed from the pigment dispersion satisfies the following condition (3). Condition (3): The difference in wavelength (λ2 - λ1) between the maximum wavelength λ1 at which the light transmittance is 20% and the minimum wavelength λ2 at which the light transmittance is 90% is 50 nm or less.

7. The pigment dispersion according to claim 1, wherein the content of C.I. pigment violet 29 is 1 to 70% by mass relative to the total mass of the pigment (A).

8. The pigment dispersion according to claim 1, wherein the viscosity of the pigment dispersion at 23°C, as measured by an E-type rotational viscometer, is 9 mPa·s or more.

9. The pigment dispersion according to claim 1, wherein the pigment (A) further comprises at least one of C.I. Pigment Blue 15:6 and C.I. Pigment Yellow 139.

10. The pigment dispersion according to claim 1, wherein the content of the dispersant (B) is 33 to 250 parts by mass per 100 parts by mass of the pigment (A).

11. The pigment dispersion according to claim 1, wherein the content of the pigment (A) is 1 to 30% by mass relative to the total mass of the pigment dispersion.

12. The pigment dispersion according to claim 1, wherein the (C) resin comprises either or both of the epoxy (meth)acrylate resin and the acrylic copolymer resin, other than the (B) dispersant.

13. The pigment dispersion according to claim 1, wherein the dispersant (B) comprises either one or both of a urethane-based polymer dispersant and an acrylic-based polymer dispersant having functional groups.

14. A composition comprising one or more resins selected from polycarbonate resin, acrylic resin, and epoxy resin, and a pigment dispersion according to any one of claims 1 to 13.

15. An infrared-transmitting filter comprising a coating film formed using a pigment dispersion according to any one of claims 1 to 13.

16. An infrared-transmitting filter comprising a coating film formed using the composition described in claim 14.

17. An infrared sensor comprising the infrared transmission filter described in claim 15.

18. An infrared sensor comprising the infrared transmission filter described in claim 16.

19. An infrared camera comprising the infrared transmission filter described in claim 15.

20. An infrared camera comprising the infrared transmission filter described in claim 16.

21. A method for producing a pigment dispersion containing (A) a pigment, (B) a dispersant, (C) a resin, and (D) a solvent, comprising mixing (A) the pigment, (B) the dispersant, (C) the resin, and (D) the solvent, wherein the (A) pigment contains C.I. Pigment Violet 29, and after allowing the pigment dispersion to stand at room temperature (20-30°C) for 24 hours or more, the median diameter (D50) of the pigment (A) observed by dynamic light scattering is 110 nm or less for a solution adjusted so that the concentration of the pigment (A) in the pigment dispersion is 100 ppm by mass.

22. A method for producing a pigment dispersion according to claim 21, wherein a coating film with a thickness of 1.7 μm formed from the pigment dispersion satisfies the following condition (1): The maximum transmittance of light at wavelengths of 450 to 600 nm is 4% or less.

23. A method for producing a pigment dispersion according to claim 21 or 22, wherein a coating film with a thickness of 1.7 μm formed from the pigment dispersion satisfies the following condition (2): The minimum transmittance of light at wavelengths of 850 to 1000 nm is 90% or more.

24. A method for producing a pigment dispersion according to any one of claims 21 to 23, wherein the coating film formed from the pigment dispersion, having a thickness of 1.7 μm, satisfies the following condition (3): Condition (3): The difference in wavelength (λ2 - λ1) between the maximum wavelength λ1 at which the light transmittance is 20% and the minimum wavelength λ2 at which the light transmittance is 90% is 50 nm or less.

25. A method for producing a pigment dispersion according to any one of claims 21 to 24, wherein the content of C.I. pigment violet 29 is 1 to 70% by mass relative to the total mass of the pigment (A).

26. A method for producing a pigment dispersion according to any one of claims 21 to 25, wherein the optical density per 1 μm of film thickness of the coating film formed from the pigment dispersion is 0.5 or more.

27. A method for producing a pigment dispersion containing (A) a pigment, (B) a dispersant, (C) a resin, and (D) a solvent, comprising mixing (A) a pigment, (B) a dispersant, (C) a resin, and (D) a solvent, wherein (A) the pigment is a perylene-based pigment having absorption in 400 to 650 nm, and at least the perylene-based pigment having a primary particle size of 20 to 150 nm as measured by scanning electron microscopy (TEM), (B) a dispersant, and (D) a solvent are dispersed using a jet mill, paint shaker, or ball mill, the pigment dispersion is left to stand at room temperature (20 to 30°C) for 24 hours or more, and the concentration of the pigment (A) in the pigment dispersion is adjusted to 100 ppm by mass, and the median diameter (D50) of the perylene-based pigment in the pigment dispersion, as observed by dynamic light scattering, is 110 nm or less.

28. The method for producing a pigment dispersion according to claim 27, wherein the content of the dispersant (B) is 33 to 250 parts by mass per 100 parts by mass of the pigment (A).

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