JP7183712B2 - Squarylium pigment and its use - Google Patents

Description

The present invention relates to a squarylium dye with a novel structure and uses thereof.

Near-infrared absorbing dyes are dyes that generally have an absorption band in the near-infrared region of 750 nm to 1200 nm. near-infrared cut filters for photographic applications, near-infrared filters for photography, near-infrared absorbing films and near-infrared absorbing plates that block heat rays for energy saving, near-infrared absorbing films for agriculture for selective use of sunlight, near-infrared It is used in recording media that utilize heat absorption, protective glasses, spectacles, sunglasses, near-infrared cut cosmetics, heat ray blocking films, electrophotographic photoreceptors, materials for laser welding, and materials for laser marking. It is also useful as a noise cut filter for CCD cameras and a filter for CMOS image sensors.

Also, near-infrared absorbing dyes have been proposed for use in the field of security printing. For example, technology that records invisible information that is not visible under normal visual conditions on documents, securities such as stock certificates, bonds, checks, gift certificates, lottery tickets, and commuter tickets, and optically reads the information. Attention has been paid. Such technology is very useful in security management and the like, and is effective in improving the added value of documents and the like, and strengthening anti-counterfeiting measures for securities and the like.

For recording invisible information, there is a method of using an image-forming material using a dye having absorption in the near-infrared region of 750 nm to 1000 nm, which is invisible to the human eye. Such invisible information can be detected by a silicon light receiving element (CCD, CMOS, etc.) or the like, even if it is invisible to the human eye.

Phthalocyanine dyes, cyanine dyes, diimmonium dyes, squarylium dyes, croconium dyes, and the like are known as dyes having absorption in the near-infrared region of 750 nm to 1000 nm. Among these, phthalocyanine dyes and cyanine dyes are widely used. Since the phthalocyanine dye has a relatively rigid structure, it is excellent in various resistances, but is inferior in transparency and invisibility due to the structure-derived absorption called the soret band in the visible light region. On the other hand, cyanine dyes, which are generally used as dyes in a dissolved state, have very high transparency and invisibility, but are remarkably poor in various resistances, particularly light resistance. Diimonium dyes, squarylium dyes, and croconium dyes also have similar characteristics to cyanine dyes.

Patent Documents 1 to 5 disclose perimidine-type squarylium dyes as invisible dyes.

JP 2009-91517 A JP 2010-106153 A JP 2010-184975 A JP 2010-184980 A JP 2009-209297 A

However, the perimidine-type squarylium dyes of Patent Documents 1 to 4 have a problem of insufficient light resistance. Further, the perimidine-type squarylium dye of Patent Document 5 has a certain degree of light resistance, but has the problem that the dye tends to aggregate and has low dispersibility.

An object of the present invention is to provide a squarylium dye that has both good dispersibility and both light resistance and dispersibility.

The squarylium dye of the present invention is a compound represented by the following general formula (1).

General formula (1)

[In general formula (1),
R ₁ to R ₅ each independently represent a hydrogen atom, a sulfo group or a halogen atom.
X ₁ to X ₄ each independently represent a hydrogen atom, an optionally substituted alkyl group, an amino group, a hydroxyl group, a cyano group, a sulfo group, a nitro group, or a halogen atom. ]

According to the present invention, it is possible to provide a squarylium dye that has both good dispersibility and both light fastness and dispersibility.

1 is an X-ray diffraction pattern of the squarylium dye [1] produced in Example 1. FIG.

Terms used herein are defined. In the present specification, "(meth)acrylic", "(meth)acrylate", "(meth)acryloyl", etc. shall mean "acrylic or methacrylic", "acrylate or methacrylate", "acryloyl or methacryloyl", etc. For example, "(meth)acrylic acid" means "acrylic acid or methacrylic acid".

<Squarylium dye>
The squarylium dye represented by the general formula (1) of the present specification (hereinafter also simply referred to as “squarylium dye”) has strong color development and high fastness derived from its chemical structure, and in addition to having a specific X It has strong crystallinity with a line diffraction peak. Therefore, in addition to the optical properties (invisibility and near-infrared absorption ability) as a near-infrared absorbing dye, both light resistance and dispersibility are achieved. The squarylium dye represented by the general formula (1) includes, for example, image-forming materials, near-infrared absorbing materials, paints, adhesives, pressure-sensitive adhesives, masterbatches, moldings, films, near-infrared cut filters, solid-state imaging devices, and heat ray cut materials. , photothermal conversion materials, materials for laser welding, and the like.

Among the squarylium dyes represented by the general formula (1), in the X-ray diffraction pattern with CuKα rays, at least Bragg angles 2θ (±0.2°) of 8.5°, 12.7°, 15.3°, and 16 It is preferable to have diffraction peaks at 0°, 17.5°, 19.6°, 22.4° and 26.6° because the light resistance is further improved.

General formula (1)

[In general formula (1),
R ₁ to R ₅ each independently represent a hydrogen atom, a sulfo group or a halogen atom.
X ₁ to X ₄ each independently represent a hydrogen atom, an optionally substituted alkyl group, an amino group, a hydroxyl group, a cyano group, a sulfo group, a nitro group, or a halogen atom. ]

The “halogen atom” for R ₁ to R ₅ includes fluorine, bromine, chlorine and iodine.

From the viewpoint of imparting light resistance, at least 4 of the 5 substitution sites of R ₁ to R ₅ are preferably hydrogen atoms, 5 of which are hydrogen atoms, 4 of which are hydrogen atoms and 1 of which is a sulfo group, and 4 of which are A hydrogen atom and one halogen atom are both more preferred, and five hydrogen atoms are particularly preferred.

The “alkyl group optionally having substituent(s)” for X ₁ to X ₄ includes methyl group, ethyl group, n-propyl group, isopropyl group, tert-butyl group, isobutyl group, tert-amyl group, 2- Ethylhexyl group, stearyl group, chloromethyl group, trichloromethyl group, trifluoromethyl group, 2-methoxyethyl group, 2-chloroethyl group, 2-nitroethyl group, and the like. Among these, a methyl group and a trifluoromethyl group are preferable from the viewpoint of synthesis difficulty.

X ₁ to X ₄ are preferably hydrogen atoms or halogen atoms from the viewpoint of dispersibility and storage stability.

<Method for producing squarylium dye>
The squarylium dye of the present specification is preferably a compound represented by general formula (1). As a method for producing the compound represented by the general formula (1), the following method can be considered.

(Synthesis example of squarylium dye)
1,8-diaminonaphthalene and adamantanone are heated under reflux together with a catalyst in a solvent to synthesize a condensate. Next, 3,4-dihydroxy-3-cyclobutene-1,2-dione is added and heated to reflux to synthesize a condensate to obtain a squarylium dye represented by the general formula (1). The above synthesis example is merely an example, and it goes without saying that other synthesis methods can be used.

(Crystal form adjustment/pigmentation)
The squarylium dye represented by the general formula (1) synthesized as described above satisfactorily achieves both light resistance and dispersibility as it is, but the squarylium dye has a specific X-ray diffraction pattern when the crystal form is adjusted as follows. can be produced. This makes it possible to achieve both high light resistance and dispersibility.

A squarylium dye having a specific X-ray diffraction pattern has at least Bragg angles 2θ (±0.2°) of 8.5°, 12.7°, 15.3°, and 16° in the X-ray diffraction pattern with CuKα rays. It has diffraction peaks at 0°, 17.5°, 19.6°, 22.4° and 26.6°.

The crystal form is preferably adjusted by contacting the squarylium dye with a specific organic solvent. A specific method is to obtain a squarylium dye having a specific X-ray diffraction pattern by filtering after mixing and stirring a specific organic solvent and a squarylium dye. At that time, heating or cooling can be performed for adjusting the particle size, and another solvent may be added before filtering.
Specific organic solvents include, for example, N,N-dimethylformamide, dimethylsulfoxide, dimethylacetamide, N-methylpyrrolidone, tetrahydrofuran, 1,4-dioxane and the like.

The squarylium dye after the above adjustment is preferably subjected to a pigmentation treatment in order to grow its crystal form more strongly. The squarylium dye tends to have a sharp average particle size distribution due to the pigmentation treatment, and for example, the dispersibility in a dispersant or a binder resin is further improved. The term "pigmentation treatment" refers to a treatment for adjusting the shape of the squarylium dye after synthesis into an appropriate particle shape.

Examples of the pigmentation method include known treatment methods such as acid pasting method and solvent salt milling method.

The acid pasting method is a method of obtaining fine squarylium pigments by adding and dissolving pigments in sulfuric acid and then dropping the sulfuric acid solution into a large amount of water to precipitate the pigments. By optimizing the amount of water used for precipitation, temperature, etc., it is possible to obtain particles with a very fine primary particle size, a narrow distribution width, and a sharp particle size distribution. .

In the solvent salt milling method, a mixture of a dye, a water-soluble inorganic salt, and a water-soluble organic solvent is heated using a kneader such as a kneader, two-roll mill, three-roll mill, ball mill, attritor, and sand mill. After mechanically kneading while washing, water-soluble inorganic salts and water-soluble organic solvents are removed by washing. The water-soluble inorganic salt acts as a crushing aid and crushes the pigment particles by utilizing the high hardness of the inorganic salt during salt milling. By optimizing the conditions for the salt milling treatment, a squarylium dye having a very fine primary particle size, a narrow distribution width, and a sharp particle size distribution can be obtained.

Examples of water-soluble inorganic salts include sodium chloride, barium chloride, potassium chloride, sodium sulfate and the like. Among these, sodium chloride (table salt) is preferable in terms of cost. The amount of the water-soluble inorganic salt to be used is preferably 50 to 2000 parts by mass, more preferably 300 to 1500 parts by mass, more preferably 500 to 1000 parts by mass with respect to 100 parts by mass of the squarylium dye, in terms of both processing efficiency and production efficiency. More preferred.

The water-soluble organic solvent functions to wet the squarylium dye and the water-soluble inorganic salt, and is preferably a compound that dissolves (miscible in) water and does not substantially dissolve the inorganic salt used. The temperature of the water-soluble organic solvent rises during salt milling, and the solvent easily evaporates. Therefore, a compound having a boiling point of 120° C. or higher is preferable from the viewpoint of safety. Water-soluble organic solvents include, for example, 2-methoxyethanol, 2-butoxyethanol, 2-(isopentyloxy)ethanol, 2-(hexyloxy)ethanol, diethylene glycol, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, triethylene glycol, triethylene glycol monomethyl ether, liquid polyethylene glycol, 1-methoxy-2-propanol, 1-ethoxy-2-propanol, dipropylene glycol, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, liquid polypropylene glycol, etc. mentioned.

The amount of the water-soluble organic solvent used is preferably 5 to 1000 parts by mass, more preferably 50 to 500 parts by mass, relative to 100 parts by mass of the squarylium dye.

If necessary, a resin can be added during the solvent salt milling treatment. Resins include, for example, natural resins, modified natural resins, synthetic resins, and synthetic resins modified with natural resins. The resin is preferably solid at room temperature (25° C.) and insoluble in water, more preferably partially soluble in water-soluble organic solvents.

The amount of the resin used is preferably 2 to 200 parts by mass with respect to 100 parts by mass of the squarylium dye.

The squarylium dyes can be used singly or in combination of two or more.

<Composition>
The composition of the present specification preferably contains a squarylium dye and resin [A], and more preferably contains an organic solvent. From the viewpoint of imparting light resistance, the squarylium dye is preferably used, for example, in a state of being dispersed in a resin or solvent.

The content of the squarylium dye in the composition of the present specification is preferably 0.05 to 50% by mass, more preferably 0.1 to 30% by mass.

In the present specification, the squarylium dyes may be used singly or as a mixture of two or more at any ratio as required.

Applications of the composition of the present specification are not particularly limited, but for example, electrophotographic toner, inkjet printer ink, thermal printer ink, letterpress printing, offset printing, flexographic printing, gravure printing, or silk printing ink and the like.

(for electrophotographic toner)
The composition of the present specification is preferably an electrophotographic toner as one embodiment. The electrophotographic toner may be used alone as a one-component developer or as a two-component developer in combination with a carrier. A known carrier can be used as the carrier. Examples of the carrier include a resin-coated carrier having a resin coating layer on a core material. A conductive powder or the like may be dispersed in the resin coating layer.

The electrophotographic toner preferably contains a squarylium dye and resin [A]. Resin [A] is also referred to as a binder, and its raw material monomers include, for example, styrene such as styrene and chlorostyrene; monoolefins such as ethylene, propylene, butylene, and isoprene; vinyl acetate, vinyl propionate, vinyl benzoate, and vinyl butyrate; vinyl esters such as methyl acrylate, ethyl acrylate, butyl acrylate, dodecyl acrylate, octyl acrylate, phenyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, α-methylene fats such as dodecyl methacrylate group monocarboxylic acid esters; vinyl ethers such as vinyl methyl ether, vinyl ethyl ether and vinyl butyl ether; vinyl ketones such as vinyl methyl ketone, vinyl hexyl ketone and vinyl isopropenyl ketone; Other resins include polyester, polyurethane, epoxy resin, silicone resin, polyamide, modified rosin, paraffin wax, and the like. Among these, polystyrene, styrene-alkyl acrylate copolymer, styrene-alkyl methacrylate copolymer, styrene-acrylonitrile copolymer, styrene-butadiene copolymer, styrene-maleic anhydride copolymer, polyethylene and polypropylene are preferable.

The electrophotographic toner may further contain a charge control agent, an anti-offset agent and the like, if necessary. Charge control agents include positive charge control agents and negative charge control agents, and positive charge control agents include quaternary ammonium compounds. Examples of the negative charge control agent include a metal complex of alkylsalicylic acid, a resin type charge control agent containing a polar group, and the like. Anti-offset agents include low-molecular-weight polyethylene, low-molecular-weight polypropylene, and the like.

In the electrophotographic toner, inorganic particles or organic particles can be added as an external additive to the surface of the toner particles in order to improve fluidity, powder preservability, triboelectrification control, transfer performance, cleaning performance, and the like. . Examples of inorganic particles include silica, alumina, titania, calcium carbonate, magnesium carbonate, calcium phosphate, and cerium oxide. Also, the inorganic particles may be subjected to a known surface treatment. Examples of organic particles include particles of vinylidene fluoride, methyl methacrylate, styrene-methyl methacrylate, and the like.

(Ink for inkjet printers)
The composition of the present specification is preferably an ink for inkjet printers as one embodiment. Inks for inkjet printers include aqueous IJ inks and non-aqueous IJ inks.

<Aqueous IJ ink>
The aqueous IJ ink preferably contains a squarylium dye, a water-soluble organic solvent, and an aqueous resin. Examples of water include ion-exchanged water, ultrafiltered water, and pure water.

Water-soluble organic solvents include, for example, polyhydric alcohols such as ethylene glycol, diethylene glycol, polyethylene glycol and glycerin; N-alkylpyrrolidone; esters such as ethyl acetate and amyl acetate; lower alcohols such as methanol, ethanol, propanol and butanol; , butanol, glycol ethers such as ethylene oxide or propylene oxide adducts of phenol; The water-soluble organic solvent can be appropriately selected in consideration of hygroscopicity, moisture retention, solubility of the squarylium dye, permeability, ink viscosity, freezing point, and the like.

A water-soluble organic solvent can be used individually or in combination of 2 or more types.

The content of the water-soluble organic solvent is preferably 1 to 60% by mass in the water-based IJ ink.

Water-based resins include water-soluble resins that dissolve in water and water-dispersible resins that disperse in water, depending on their form. Materials for the aqueous resin include, for example, acrylic resins, styrene-acrylic resins, polyester resins, polyamide resins, polyurethane resins, fluorine resins, and the like.

Aqueous IJ inks can also contain surfactants to improve pigment dispersion and image quality. Surfactants include anionic, nonionic, cationic and amphoteric depending on their ionic properties. Among these, anionic and nonionic are preferred. Anionic surfactants include, for example, fatty acid salts, alkylsulfuric acid ester salts, alkylbenzenesulfonates, alkylnaphthalenesulfonates, dialkylsulfosuccinates, alkyldiarylether disulfonates, alkylphosphates, polyoxyethylene alkyl ethers Sulfates, polyoxyethylene alkylaryl ether sulfates, naphthalenesulfonic acid formalin condensates, polyoxyethylene alkyl phosphate ester salts, glycerol borate fatty acid esters, polyoxyethylene glycerol fatty acid esters, and the like.

Nonionic surfactants include, for example, polyoxyethylene alkyl ethers, polyoxyethylene alkylaryl ethers, polyoxyethyleneoxypropylene block copolymers, sorbitan fatty acid esters, polyoxyethylene sorbitan fatty acid esters, polyoxyethylene sorbitol fatty acid esters, glycerin fatty acid Examples thereof include esters, polyoxyethylene fatty acid esters, polyoxyethylene alkylamines, fluorine-based resins, and silicone-based resins.

<Non-aqueous IJ ink>
The non-aqueous IJ ink preferably contains squarylium, an organic solvent, and a non-aqueous resin. Also, the non-aqueous IJ ink may be of an ultraviolet curable type.

Examples of organic solvents include aromatic solvents such as toluene, xylene and methoxybenzene; acetic acid ester solvents such as ethyl acetate, butyl acetate, propylene glycol monomethyl ether acetate and propylene glycol monoethyl ether acetate; methyl lactate; Lactate ester solvents such as propyl lactate, butyl lactate, ethylhexyl lactate, amyl lactate and isoamyl lactate, propionate solvents such as ethoxyethyl propionate, alcohol solvents such as methanol and ethanol, butyl cellosolve, propylene glycol monomethyl ether, diethylene glycol ethyl Ether, ether solvents such as diethylene glycol dimethyl ether, ketone solvents such as methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone, aliphatic hydrocarbon solvents such as hexane, N,N-dimethylformamide, N,N-dimethylacetamide, γ-butyrolactam , N-methyl-2-pyrrolidone, aniline, pyridine and other nitrogen compound solvents, γ-butyrolactone and other lactone solvents, and carbamic acid esters such as a 48:52 mixture of methyl carbamate and ethyl carbamate. be done.

Non-aqueous resins are binders such as petroleum-based resins, casein, shellac, rosin-modified maleic acid resins, rosin-modified phenolic resins, nitrocellulose, cellulose acetate butyrate, cyclized rubber, chlorinated rubber, oxidized rubber, and hydrochlorinated rubber. , phenol resin, alkyd resin, polyester resin, unsaturated polyester resin, amino resin, epoxy resin, vinyl resin, vinyl chloride, vinyl chloride-vinyl acetate copolymer, acrylic resin, methacrylic resin, polyurethane resin, silicone resin, fluorine resin , drying oil, synthetic drying oil, styrene/maleic acid resin, styrene/acrylic resin, polyamide resin, polyimide resin, benzoguanamine resin, melamine resin, urea resin, chlorinated polypropylene, butyral resin, vinylidene chloride resin, and the like. A photocurable resin may be used as the non-aqueous resin.

Examples of the main chain skeleton of the comb-shaped dispersant include polyurethane, polyacrylic acid, polyacrylic acid ester, polyacrylonitrile, polyester, polyamide, polyimide, polyurea, polyallylamine, and polyethyleneimine. Examples of the side chain skeleton of the comb-shaped dispersant include polyesters such as polyurethane, polyacrylic acid, polyacrylic ester, polyacrylonitrile, polycaprolactone and polyvalerolactone. Among these, an oxyalkylenecarbonyl group whose main chain skeleton is polyallylamine or polyethyleneimine and whose side chain skeleton is a polyester reacted with polycaprolactone, polyvalerolactone, or the like, can suppress the viscosity of non-aqueous IJ ink. A comb-shaped dispersant is preferred, and a comb-shaped dispersant having a polyethyleneimine main chain skeleton and an oxyalkylenecarbonyl group as a side chain skeleton is more preferred.

An example of a method for synthesizing a comb-shaped dispersant having a main chain skeleton of polyethylenimine and a side chain skeleton of an oxyalkylenecarbonyl group is described. is reacted with an organic acid, and then polyamine or polyimine such as polyethyleneimine is reacted at 100 to 180° C. under a nitrogen atmosphere.

In ink applications for inkjet printers, a dispersant can be appropriately selected and contained. This results in better quality dye dispersion and image quality. Dispersants include straight-chain and comb-type according to their structure. Among these, a comb shape is preferable in that the squarylium dye can be easily dispersed.

In addition, when used as an ink for inkjet printers, it may further contain additives. Examples of additives include pH adjusters, resistivity adjusters, antioxidants, preservatives, antifungal agents, sequestering agents, and the like. Examples of pH adjusters include alcohol amines, ammonium salts, metal hydroxides, and the like. Moreover, organic salts and inorganic salts are mentioned as a resistivity adjuster. A chelating agent etc. are mentioned as a sequestering agent.

Additives other than those mentioned above may be added to the extent that they do not clog the jetting nozzle of an inkjet printer or change the direction of ink ejection. Water-soluble resins such as acid resins can be included.

(Other uses)
In other embodiments, the compositions herein are preferably inks for thermal printers, letterpress printing, offset printing, flexographic printing, gravure printing, or silk printing. These inks are preferably oil-based inks containing a resin and a water-insoluble solvent. Resins include, for example, proteins, rubbers, celluloses, shellac, copal, starch, natural resins such as rosin; thermoplastic resins such as vinyl resins, acrylic resins, styrene resins, polyolefin resins, and novolac-type phenol resins; Thermosetting resins such as urea resins such as resol-type phenol resins, melamine resins, polyurethane resins, epoxies, and unsaturated polyesters can be used. As the water-insoluble solvent, the water-insoluble solvents already described can be used.

The ink appropriately contains additives such as a plasticizer for improving the flexibility and strength of the printed film, a solvent for adjusting viscosity and improving drying properties, a desiccant, a viscosity adjusting agent, a dispersant, and various reactive agents. can.

The ink can contain stabilizers. A stabilizer is a compound that receives energy from the excited state near-infrared absorbing dye. The stabilizer preferably has an absorption band on the longer wavelength side than the absorption band of the infrared absorbing dye. Moreover, it is preferable that the stabilizer is not easily decomposed by singlet oxygen and has high compatibility with the squarylium dye. Stabilizers include, for example, organometallic complex compounds. Among these, Ni complex compounds are preferred.

(Method for producing composition)
An example of the method for producing the composition of the present specification is described below.
For example, when the squarylium dye is used in a dispersed state, a method of mixing the squarylium dye and a dispersant and subjecting the mixture to dispersion treatment can be used. As will be described later, the dispersant is a compound capable of dispersing the squarylium dye, and examples thereof include low-molecular-weight dispersants such as surfactants and high-molecular-weight dispersants such as resin-type dispersants. Also, the dispersant has an adsorptive group and a dispersing site. The adsorptive group adsorbs to the squarylium dye, for example, a carboxylic acid group, a sulfonic acid group, an acidic group such as a phosphoric acid group, a primary amino group, a secondary amino group, a tertiary amino group, a base such as a quaternary ammonium salt. and a neutral group such as a hydroxyl group. Examples of dispersed sites include units containing hydrocarbon chains and aromatic rings.

(Invisibility evaluation method)
The squarylium dye of the present specification has sufficiently low absorbance in the visible light wavelength region of 400 nm or more and 750 nm or less, and sufficiently high absorbance in the near-infrared light wavelength region of 750 nm or more and 1000 nm or less, and has excellent light resistance. . Therefore, the composition of the present specification containing the squarylium dye of the present specification can achieve both the invisibility of information and the readability of invisible information, and is stable for a long period of time in a recording medium on which invisible information is recorded. It is possible to achieve

The squarylium dye of the present specification preferably satisfies the conditions represented by the following formulas (I) and (II). By satisfying the conditions represented by the following formulas (I) and (II), it is possible to achieve both the invisibility of displayed information and the readability of invisible information, regardless of the color tone of the image forming material. , it becomes possible to realize long-term reliability in a recording medium on which invisible information is recorded.
0≦ΔE≦15 (I)
(100-R)≧75 (II)
[In the formula (II), ΔE is the following formula (III):

Formula (III)

[In formula ( _III ), _{L 1} , a ₁ , and b ₁ represent _the L value, a value, and b value of the surface of the recording medium before image formation, respectively; The L value, a value, and b value in the image portion when a fixed image having an adhesion amount of 4 g/m ² was formed on the surface of the recording medium using the forming material are shown. ) represents the color difference in the CIE1976L*a*b* color system, and in formula (II), R (unit: %) represents the infrared reflectance at a wavelength of 850 nm in the image portion. ]

L ₁ , a ₁ , b ₁ , L ₂ , a ₂ , b ₂ can be measured using a reflection spectrodensitometer. In this specification, L ₁ , a ₁ , b ₁ , L ₂ , a ₂ , and b ₂ were measured using an x-rite 939 manufactured by X-Rite Co., Ltd. as a reflection spectral densitometer.

For invisible information recorded using the composition of the present specification, it is preferable to use a semiconductor laser or a light-emitting diode that emits light at any wavelength of 750 nm or more and 1000 nm or less as a light source for optical reading. In addition, by using a general-purpose light receiving element having high spectral sensitivity to near-infrared light, reading can be performed very easily and with high sensitivity. Examples of the light-receiving element include a light-receiving element (such as a CCD) made of silicon.

<Near-infrared absorbing composition>
The near-infrared absorbing composition of the present specification is one selected from the group consisting of a squarylium dye, a resin [A], a dispersant [B], a photopolymerizable compound, a photopolymerization initiator, an organic solvent, and water. and above. In addition to these, curing agents, curing accelerators, chain transfer agents, antioxidants, leveling agents, light-absorbing dyes, light stabilizers, ultraviolet absorbers, inorganic fine particles, activators, antifoaming agents, etc. can be contained. .

In the near-infrared absorbing composition of the present specification, the squarylium dye is particularly preferably used in a dispersed state from the viewpoint of imparting resistance. In the near-infrared absorbing composition of the present specification, the squarylium dyes may be used singly or as a mixture of two or more at any ratio as needed.

The near-infrared absorbing composition containing the strongly crystalline squarylium dye of the present specification has excellent optical properties (invisibility and near-infrared absorption ability) as a near-infrared absorbing dye, various resistances, and is resistant to aggregation. is easily dispersed and has excellent storage stability. It can be suitably used for various purposes such as materials for applications.

<Resin [A]>
As the resin [A] of the present specification, as described below, depending on the application and required performance, known water-based / solvent-based resins can be used without limitation. Alternatively, two or more types can be used in combination.

(When used as a coating, such as paint)
When the near-infrared absorbing composition of the present specification is used for coating such as a paint, the resin [A] preferably has a binder function, for example, an aliphatic ester resin, an acrylic resin , methacrylic resin, melamine resin, urethane resin, aromatic ester resin, polycarbonate resin, aliphatic polyolefin resin, aromatic polyolefin resin, polyvinyl resin, polyvinyl alcohol resin, modified polyvinyl resin, polyvinyl chloride resin, styrene-butadiene copolymer , polystyrene resin, polyamide resin, butyral resin, styrene-maleic acid copolymer, chlorinated polyethylene, chlorinated polypropylene, vinyl chloride-vinyl acetate copolymer, polyvinyl acetate, alkyd resin, rubber resin, cyclized rubber Examples include, but are not limited to, resins, polybutadiene, polyimide resins, and copolymer resins thereof. Also included are natural polymeric materials such as gelatin, casein, starch, cellulose derivatives, and alginic acid.

(When used in the form of alkali-developable resist)
The near-infrared absorbing composition of the present specification is preferably an alkali-developable resist as an embodiment. The alkali-developable resist is preferably used for forming a layer constituting a part of a display, an imaging device, or the like by a photolithographic method.

The alkali-developable resist preferably uses an alkali-soluble vinyl resin obtained by copolymerizing an ethylenically unsaturated monomer containing an acidic group as a binder resin. Also, the alkali-soluble vinyl resin may be an active energy ray-curable resin having an ethylenically unsaturated double bond in order to improve the photosensitivity and solvent resistance of the resist.

Alkali-soluble vinyl resins include, for example, resins having acidic groups such as aliphatic carboxyl groups and sulfone groups. Alkali-soluble vinyl resins include, for example, acrylic resins having acidic groups, α-olefin/(anhydride) maleic acid copolymers, styrene/styrenesulfonic acid copolymers, ethylene/(meth)acrylic acid copolymers, or isobutylene/(anhydrous) maleic acid copolymer and the like. Among these, acrylic resins and styrene/styrene sulfonic acid copolymers having acidic groups are preferable, and acrylic resins having acidic groups are more preferable in terms of improving heat resistance and transparency.

Active energy ray-curable resins having ethylenically unsaturated double bonds include, for example, resins into which unsaturated ethylenic double bonds are introduced by methods (a) and (b) shown below.

[Method (a)]
As method (a), for example, the side chain epoxy group of a copolymer obtained by copolymerizing an unsaturated ethylenic monomer having an epoxy group and one or more other monomers. , the carboxyl group of an unsaturated monobasic acid having an unsaturated ethylenic double bond undergoes an addition reaction. Next, there is a method of reacting the generated hydroxyl group with a polybasic acid anhydride to introduce an unsaturated ethylenic double bond and a carboxyl group.

Unsaturated ethylenic monomers having an epoxy group include, for example, glycidyl (meth)acrylate, methylglycidyl (meth)acrylate, 2-glycidoxyethyl (meth)acrylate, 3,4 epoxybutyl (meth)acrylate, and 3,4 epoxycyclohexyl (meth)acrylates can be mentioned. Among these, glycidyl (meth)acrylate is preferable from the viewpoint of reactivity with the unsaturated monobasic acid in the next step.

Examples of unsaturated monobasic acids include monocarboxylic acids such as (meth)acrylic acid, crotonic acid, α-position haloalkyl, alkoxyl, halogen, nitro, and cyano-substituted (meth)acrylic acids.

Examples of polybasic acid anhydrides include succinic anhydride and maleic anhydride.

These raw materials can be used alone or in combination of two or more.

As a method similar to method (a), for example, a copolymer obtained by copolymerizing an unsaturated ethylenic monomer having an aliphatic carboxyl group and one or more other monomers There is a method in which an unsaturated ethylenic monomer having an epoxy group is added to a part of the side-chain aliphatic carboxyl groups to introduce an unsaturated ethylenic double bond and an aliphatic carboxyl group.

[Method (b)]
As the method (b), an unsaturated ethylenic monomer having a hydroxyl group is used, and another unsaturated monobasic acid monomer having an aliphatic carboxyl group or another monomer is copolymerized. There is a method of reacting the side chain hydroxyl groups of the copolymer obtained by the reaction with the isocyanate groups of the unsaturated ethylenic monomer having isocyanate groups.

Examples of unsaturated ethylenic monomers having a hydroxyl group include 2-hydroxyethyl (meth)acrylate, 2- or 3-hydroxypropyl (meth)acrylate, 2- or 3- or 4-hydroxybutyl (meth)acrylate, glycerol (Meth)acrylates or hydroxyalkyl (meth)acrylates such as cyclohexanedimethanol mono(meth)acrylate can be mentioned. In addition, polyether mono(meth)acrylate obtained by addition polymerization of ethylene oxide, propylene oxide, and/or butylene oxide, etc. to the above hydroxyalkyl (meth)acrylate, (poly)γ-valerolactone, (poly)ε-caprolactone and/or (poly)ester mono(meth)acrylates added with (poly)12-hydroxystearic acid or the like. 2-Hydroxyethyl (meth)acrylate or glycerol (meth)acrylate is preferred from the viewpoint of suppressing coating film foreign substances.

The unsaturated ethylenic monomer having an isocyanate group includes 2-(meth)acryloyloxyethyl isocyanate, 1,1-bis[(meth)acryloyloxy]ethyl isocyanate, and the like.

These raw materials can be used alone or in combination of two or more.

<Dispersant [B]>
Dispersant [B] is a compound capable of dispersing the squarylium dye. Low molecular type dispersants such as surfactants and polymeric type dispersants such as resin type dispersants can be used. Among these, resin-type dispersants are preferred. Also, the dispersant has an adsorptive group that has an affinity for the dye and a dispersing site that disperses throughout the composition. Adsorbing groups include acidic groups such as carboxylic acid groups, sulfonic acid groups, and phosphoric acid groups; basic groups such as primary amino groups, secondary amino groups, tertiary amino groups, and quaternary ammonium bases; sexual group; Examples of dispersed sites include units containing hydrocarbon chains and aromatic rings.

(Dispersant having a tertiary amino group and/or a quaternary ammonium base)
The dispersing agent [B] is preferably a dispersing agent having a tertiary amino group and/or a quaternary ammonium base in terms of suppressing the viscosity of the near-infrared absorbing composition and improving storage stability. is more preferred. Further, the dispersant [B] preferably has a block structure because a random structure and a block structure can be used without limitation.

Dispersant [B] having a tertiary amino group and a quaternary ammonium base is an ethylenically unsaturated monomer having a tertiary amino group, an ethylenically unsaturated monomer having a quaternary ammonium base, and if necessary Copolymers of other ethylenically unsaturated monomers are preferred. Incidentally, after polymerizing a copolymer containing an ethylenically unsaturated monomer having a tertiary amine instead of using an ethylenically unsaturated monomer having a quaternary ammonium salt, benzyl chloride or the like is added to the copolymer. A quaternary ammonium base can also be generated by reacting the halogenated hydrocarbon compound of ##STR00004## and partially converting the tertiary amino group to a quaternary ammonium chloride.

The ethylenically unsaturated monomer having a tertiary amino group is preferably a compound represented by the following general formula (5).

general formula (5)

[In the general formula (5), R ⁵¹ and R ⁵² each independently represent a hydrogen atom or a chain or cyclic hydrocarbon group which may have a substituent, and R ⁵¹ and R ⁵² are bonded to each other may form a cyclic structure. ^R53 represents a hydrogen atom or a methyl group, and ^X101 represents a divalent linking group. ]

Among the substituents on the hydrocarbon group represented by R ⁵¹ and R ⁵² in the general formula (5), examples of substituents on the chain hydrocarbon group include a halogen atom, an alkoxy group, a benzoyl group, and a hydroxyl group. . Further, examples of substituents on the cyclic hydrocarbon group include chain alkyl groups, halogen atoms, alkoxy groups, and hydroxyl groups. The chain hydrocarbon groups represented by ^R51 and ^R52 include both linear and branched hydrocarbon groups.

R ⁵¹ and R ⁵² in the general formula (5) are more preferably an optionally substituted alkyl group having 1 to 4 carbon atoms, preferably a methyl group, an ethyl group, a propyl group or a butyl group.

In general formula (5), the cyclic structure in which R ⁵¹ and R ⁵² are bonded to each other includes, for example, a 5- to 7-membered nitrogen-containing heterocyclic monocyclic ring and a condensed ring formed by condensing two of these. The nitrogen-containing heterocyclic ring is preferably non-aromatic, more preferably saturated. Examples of R ⁵¹ and R ⁵² include the following structures. These cyclic structures may further have a substituent.

^{[ _ _} provided that R ⁵⁸ and R ⁵⁹ are a single bond, a methylene group, an alkylene group having 2 to 10 carbon atoms, or an ether group having 2 to 10 carbon atoms (including an alkyloxyalkyl group and the like). A -COO-R ⁵⁹ - group is preferred.

Ethylenically unsaturated monomers having a tertiary amino group represented by formula (5) include, for example, dimethylaminoethyl (meth)acrylate, diethylaminoethyl (meth)acrylate, dimethylaminopropyl (meth)acrylate, diethylaminopropyl ( meth)acrylate, dimethylaminopropyl (meth)acrylamide and the like.

The ethylenically unsaturated monomer having a quaternary ammonium base is preferably a compound represented by the following general formula (7).

general formula (7)

[In general formula (7), R ⁵⁴ to R ⁵⁶ each independently represent a hydrogen atom or a chain or cyclic hydrocarbon group which may have a substituent, and 2 of R ⁵⁴ to R ⁵⁶ One or more may be attached to each other to form a ring structure. R ⁵⁷ represents a hydrogen atom or a methyl group, X ¹⁰² represents a divalent linking group, and L ^- represents a counter anion. ]

Among the substituents on the hydrocarbon group represented by R ⁵⁴ to R ⁵⁶ in the general formula (7), examples of substituents on the chain hydrocarbon group include a halogen atom, an alkoxy group, a benzoyl group, and a hydroxyl group. . Further, examples of substituents on the cyclic hydrocarbon group include chain alkyl groups, halogen atoms, alkoxy groups, and hydroxyl groups. The chain hydrocarbon groups represented by R ⁵⁴ to R ⁵⁶ include both linear and branched hydrocarbon groups.

R ⁵⁴ to R ⁵⁶ in general formula (7) are more preferably an optionally substituted alkyl group having 1 to 4 carbon atoms, preferably a methyl group, an ethyl group, a propyl group or a butyl group.

In the general formula (7), the cyclic structure formed by combining two or more of R ⁵⁴ to R ⁵⁶ with each other is, for example, a 5- to 7-membered nitrogen-containing heterocyclic monocyclic ring or a condensed and condensed rings. The nitrogen-containing heterocyclic ring is preferably non-aromatic, more preferably saturated. Specific examples include the following structures.

In general formula (7), R is any one of R ⁵⁴ to R ⁵⁶ . These cyclic structures may further have a substituent.

In general formula (7), the divalent linking group X ¹⁰² is the same as X ¹⁰¹ in general formula (5) above. Examples of the counter anion L ⁻ in formula (7) include Cl ⁻ , Br ⁻ , I ⁻ , ClO4 ⁻ , BF ₄ ⁻ , CH ₃ COO ⁻ , PF ₆ ⁻ and the like.

Examples of ethylenically unsaturated monomers having a quaternary ammonium base represented by general formula (7) include (meth)acryloylaminopropyltrimethylammonium chloride, (meth)acryloyloxyethyltrimethylammonium chloride, (meth)acryloyloxy ethyltriethylammonium chloride, (meth)acryloyloxyethyl(4-benzoylbenzyl)dimethylammonium bromide, (meth)acryloyloxyethylbenzyldimethylammonium chloride, (meth)acryloyloxyethylbenzyldiethylammonium chloride and the like. Among these, (meth)acryloyloxyethyltrimethylammonium chloride is preferred.

The resin-type dispersant having a tertiary amino group and a quaternary ammonium base preferably has an amine value of 10 to 250 mgKOH/g and a quaternary ammonium salt value of 10 to 90 mgKOH/g, and an amine value of 50 to 200 mgKOH/g. , and a quaternary ammonium salt value of 10 to 50 mgKOH/g is more preferable.

The weight average molecular weight (Mw) of the dispersant [B] is preferably 3,000 to 300,000, more preferably 5,000 to 30,000.

<Photopolymerizable compound>
Photopolymerizable compounds include monomers or oligomers that are cured by ultraviolet rays, heat, or the like to form transparent resins. The photopolymerizable compound is preferably a photopolymerizable compound having 3 to 12 ethylenically unsaturated bond groups in one molecule.

Photopolymerizable compounds are monomers and oligomers, such as phenoxytetraethyleneglycol (meth)acrylate, phenoxyhexaethyleneglycol (meth)acrylate, EO (hereinafter also referred to as ethyleneoxy)-modified phthalic acid (meth)acrylate, PO (hereinafter also referred to as propyleneoxy) modified phthalic acid (meth)acrylate, acrylated disocyanurate, bis(acryloxyneopentyl glycol) adipate, polyethylene glycol 200 (number of moles added) di(meth)acrylate, polyethylene glycol 400 ( Number of moles added) di(meth)acrylate, tetraethylene glycol di(meth)acrylate, EO-modified trimethylolpropane triacrylate, PO-modified trimethylolpropane tri(meth)acrylate, tripropylene glycol di(meth)acrylate, tris(acrylate) oxyethyl) isocyanurate, caprolactone-modified tris(acryloxyethyl) isocyanurate, neopentyl glycol hydroxypivalate di(meth)acrylate, pentaerythritol tri(meth)acrylate, dicyclopentanyl di(meth)acrylate, EO-modified bisphenol A di(meth)acrylate, dipentaerythritol hexa(meth)acrylate, dipentaerythritol monohydroxypenta(meth)acrylate, alkyl-modified dipentaerythritol penta(meth)acrylate, caprolactone-modified dipentaerythritol hexa(meth)acrylate, etc. mentioned.
Also, for example, methyl (meth)acrylate, ethyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, cyclohexyl (meth)acrylate, β-carboxyethyl (meth)acrylate, polyethylene Glycol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, triethylene glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol tri( meth)acrylate, pentaerythritol tetra(meth)acrylate, 1,6-hexanediol diglycidyl ether di(meth)acrylate, bisphenol A diglycidyl ether di(meth)acrylate, neopentyl glycol diglycidyl ether di(meth)acrylate, Dipentaerythritol hexa(meth)acrylate, dipentaerythritol penta(meth)acrylate, tricyclodecanyl(meth)acrylate, ester acrylate, methylolated melamine (meth)acrylate, epoxy(meth)acrylate, urethane acrylate, etc. various acrylic and methacrylic acid esters, (meth)acrylic acid, styrene, vinyl acetate, hydroxyethyl vinyl ether, ethylene glycol divinyl ether, pentaerythritol trivinyl ether, (meth)acrylamide, N-hydroxymethyl (meth)acrylamide, N - vinylformamide, acrylonitrile and the like.

These commercial products are manufactured by Nippon Kayaku Co., Ltd., KAYARAD DPHA, KAYARAD DPEA-12, KAYARAD DPHA-2C, KAYARAD D-310, KAYARAD D-330, KAYARAD DPCA-20, KAYARAD DPCA-30, KAYARAD DPCA-60, KAYARAD DPCA-120, KAYARAD R526, KAYARAD PEG400DA, KAYARAD R-167, KAYARAD HX-220, KAYARAD R-551, KAYARAD R712, KAYARAD R-604, KAYARAD MP-684, KAYARAD TPO, and Toa Synthesis, KAYARAD M210, M220, M225, M305, M309, M325, M350, M-402 manufactured by Osaka Organic Co., Ltd. Viscoat 195, Viscoat 230, Viscoat 260, Viscoat 215, Viscoat 310, Viscoat 214HP, Viscoat 295, Viscoat 300, Viscoat 360 , Viscoat GPT, Viscoat 400, Viscoat 700, Viscoat 540, Viscoat 3000, Viscoat 3700 and the like.

The amount of the photopolymerizable compound is preferably 5 to 400 parts by mass, more preferably 10 to 300 parts by mass, per 100 parts by mass of the squarylium dye. When blended in an appropriate amount, the photocurability and developability are further improved.

A photopolymerizable compound can be used individually or in combination of 2 or more types.

<Photoinitiator>
When the near-infrared absorbing composition of the present specification contains a photopolymerizable compound, it preferably contains a photopolymerization initiator.
Examples of photopolymerization initiators include oxime ester-based initiators and aminoketone-based photopolymerization initiators.

(Oxime ester photopolymerization initiator)
Examples of oxime ester photopolymerization initiators include acetophenone, benzophenone, 4,4′-bis(diethylamino)-benzophenone, 4-(methylphenylthio)-phenylphenylketone, benzyldimethylketal, 2-methyl-1- methylthiophenyl-2-morpholinopropan-1-one, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)butan-1-one, ethyl p-diethylaminobenzoate, thioxanthone, 2,5- diethylthioxanthone, 2-chloroxanthone, isopropylthioxanthone, 1-chloro-4-propoxy-thioxanthone, 2-(o-chlorophenyl)-4,5-diphenylimidazole dimer, 2-(o-fluorophenyl)-4, 5-diphenylimidazole dimer, 2-(o-methoxyphenyl)-4,5-diphenylimidazole dimer, 2-(p-methoxyphenyl)-4,5-diphenylimidazole dimer, 2-(o -chlorophenyl)-4,5-di(o-methoxyphenyl)imidazole dimer, 9-phenylacridine, 9-(p-toluyl)acridine, 1,7-bis(9,9′-acridinyl)heptane, N -phenylglycine, bis(η5-cyclopentadienyl)bis[2,6-difluoro-3-(1H-pyrrol-1-yl)phenyl]titanium, 2-ethylanthraquinone, 1-chloroanthraquinone, 2-phenyl- 4,6-bis(trichloromethyl)-s-triazine, 2-(4-methoxyphenyl)-4,6-bis(trichloromethyl)-s-triazine, 2-naphthyl-4,6-bis(trichloromethyl) -s-triazine, 2-(4-methoxynaphthyl)-4,6-bis(trichloromethyl)-s-triazine, 2-methyl-4,6-bis(trichloromethyl)-s-triazine and the like.

(Aminoketone-based photopolymerization initiator)
Examples of aminoketone-based photopolymerization initiators include the following compounds. For example, 2-dimethylamino-2-methyl-1-phenylpropan-1-one, 2-diethylamino-2-methyl-1-phenylpropan-1-one, 2-methyl-2-morpholino-1-phenylpropan- 1-one, 2-dimethylamino-2-methyl-1-(4-methylphenyl)propan-1-one, 2-dimethylamino-1-(4-ethylphenyl)-2-methylpropan-1-one, 2-dimethylamino-1-(4-isopropylphenyl)-2-methylpropan-1-one, 1-(4-butylphenyl)-2-dimethylamino-2-methylpropan-1-one, 2-dimethylamino -1-(4-methoxyphenyl)-2-methylpropan-1-one, 2-dimethylamino-2-methyl-1-(4-methylthiophenyl)propan-1-one, 2-methyl-1-(4 -methylthiophenyl)-2-morpholinopropan-1-one (IRGACURE 907), 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butan-1-one (IRGACURE 369), 2- benzyl-2-dimethylamino-1-(4-dimethylaminophenyl)-butan-1-one, 2-dimethylamino-2-[(4-methylphenyl)methyl]-1-[4-(4-morpholinyl) phenyl]-1-butanone (IRGACURE 379) and the like.

The near-infrared absorbing composition can contain other photopolymerization initiators in addition to or in combination with the oxime ester-based photopolymerization initiator and aminoketone-based photopolymerization initiator.
Other photopolymerization initiators include, for example, 2,4,6-trichloro-s-triazine, 2-phenyl-4,6-bis(trichloromethyl)-s-triazine, 2-(p-methoxyphenyl)-4, 6-bis(trichloromethyl)-s-triazine, 2-(p-tolyl)-4,6-bis(trichloromethyl)-s-triazine, 2-piperonyl-4,6-bis(trichloromethyl)-s- Triazine, 2,4-bis(trichloromethyl)-6-styryl-s-triazine, 2-(naphth-1-yl)-4,6-bis(trichloromethyl)-s-triazine, 2-(4-methoxy -naphth-1-yl)-4,6-bis(trichloromethyl)-s-triazine, 2,4-trichloromethyl-(piperonyl)-6-triazine, or 2,4-trichloromethyl-(4'-methoxy triazine compounds such as styryl)-6-triazine; quinone-based compounds such as nanthrenequinone, camphorquinone, and ethylanthraquinone; borate-based compounds; carbazole-based compounds; imidazole-based compounds;

A photoinitiator can be used individually or in combination of 2 or more types.

The blending amount of the photopolymerization initiator is preferably 5 to 200 parts by mass, more preferably 10 to 150 parts by mass, per 100 parts by mass of the squarylium dye. When blended in an appropriate amount, the photocurability and developability are further improved.

<Organic solvent>
The near-infrared absorbing composition herein can contain an organic solvent. This aids in dispersing the squarylium pigment and facilitates adjustment of the viscosity of the composition.
Examples of organic solvents include hydrocarbon-based, alcohol-based, ketone-based, ester-based, ether-based, amide-based, and halogen-based solvents.

<Other ingredients>
(Curing agent, curing accelerator)
The near-infrared absorption composition of this specification can contain a hardening|curing agent and a hardening accelerator, when containing a thermosetting resin. Curing agents include, for example, phenol-based resins, amine-based compounds, acid anhydrides, active esters, carboxylic acid-based compounds, and sulfonic acid-based compounds. Also included are compounds having two or more phenolic hydroxyl groups in one molecule, and amine-based curing agents. Curing accelerators include, for example, amine compounds (e.g., dicyandiamide, benzyldimethylamine, 4-(dimethylamino)-N,N-dimethylbenzylamine, 4-methoxy-N,N-dimethylbenzylamine, 4-methyl-N , N-dimethylbenzylamine, etc.), quaternary ammonium salt compounds (e.g., triethylbenzylammonium chloride, etc.), blocked isocyanate compounds (e.g., dimethylamine, etc.), imidazole derivatives bicyclic amidine compounds and salts thereof (e.g., imidazole, 2-methylimidazole, 2-ethylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 4-phenylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-(2-cyanoethyl)-2-ethyl- 4-methylimidazole, etc.), phosphorus compounds (e.g., triphenylphosphine, etc.), guanamine compounds (e.g., melamine, guanamine, acetoguanamine, benzoguanamine, etc.), S-triazine derivatives (e.g., 2,4-diamino-6-methacryloyl Oxyethyl-S-triazine, 2-vinyl-2,4-diamino-S-triazine, 2-vinyl-4,6-diamino-S-triazine isocyanuric acid adduct, 2,4-diamino-6-methacryloyloxy ethyl-S-triazine/isocyanuric acid adduct, etc.) can be used.

Curing agents and curing accelerators can be used alone or in combination of two or more.

The amount of the curing agent and the curing accelerator used is about 0.01 to 15 parts by mass with respect to 100 parts by mass of the thermosetting resin.

(coloring agent)
The near-infrared absorbing composition of the present specification may contain a coloring agent other than the squarylium dye for the purpose of making the color tone less visible to the naked eye. Colorants include pigments and dyes.

The content of other coloring agents is preferably 1 to 10 parts by mass with respect to 100 parts by mass of the squarylium dye.

(Other ingredients)
The near-infrared absorption composition of this specification can contain other components as needed. Other components include chain transfer agents, antioxidants, leveling agents, light-absorbing dyes, light stabilizers, ultraviolet absorbers, inorganic fine particles, activators, antifoaming agents and the like.

<Solid-state image sensor applications>
Compositions containing the squarylium dyes herein can also be used for solid-state imaging device applications. In particular, it is preferably used as a near-infrared absorbing composition.
The solid-state imaging device composition of the present specification preferably contains a squarylium dye, a resin [A], and a dispersant [B]. The composition for a solid-state imaging device can further contain a photopolymerizable compound, a photopolymerization initiator, and an organic solvent, if necessary.
As described above, the near-infrared absorbing composition for a solid-state imaging device is obtained by dispersing the squarylium dye and the resin [A] together with a dispersant [B] capable of dispersing the squarylium dye. can be done. Examples of dispersing means include, but are not limited to, kneaders, two-roll mills, three-roll mills, ball mills, horizontal sand mills, vertical sand mills, annular bead mills, and attritors.

(Removal of coarse particles)
The near-infrared absorbing composition for a solid-state imaging device is separated into coarse particles of 5 µm or more, preferably 1 µm or more, more preferably 0.5 µm or more, by means of centrifugation, sintered filters, membrane filters, or the like. Removal of particles and entrained dust is preferred. Thus, it is preferable that the near-infrared absorbing composition for a solid-state imaging device of the present specification does not substantially contain particles of 0.5 μm or more. More preferably, it is 0.3 μm or less.

(near-infrared cut filter)
The infrared cut filter of the specification preferably comprises a substrate and a layer formed from the composition for a solid-state imaging device. Said layer can be produced by a printing method or a photolithographic method and an etching method.

Formation of the layer by the printing method enables patterning by simply repeating printing and drying of the near-infrared absorbing composition, so that the production method is low cost and excellent in mass productivity. Furthermore, the development of printing technology has made it possible to print fine patterns with high dimensional accuracy and smoothness. For printing, it is preferred that the composition does not dry or solidify on the printing plate or blanket. Controlling the fluidity of the composition on a printing machine is also important, and the viscosity of the composition can be adjusted by using a dispersant or an extender.

When forming a layer by photolithography, a near-infrared absorbing composition prepared as a solvent-developable or alkali-developable resist is applied onto a transparent substrate by a coating method such as spray coating, spin coating, slit coating, or roll coating. , so that the dry film thickness is 0.2 to 5 μm. If necessary, the dried layer is exposed to ultraviolet light through a mask having a predetermined pattern provided in contact or non-contact with this layer. After that, the film is immersed in a solvent or alkaline developer or sprayed with a developer to remove the uncured portion to form a desired pattern, and then the same operation is repeated for other colors to produce a filter. can be done. Further, heating may be applied as necessary to promote polymerization of the resist. The photolithographic method can produce filters with higher precision than the printing method.

When forming the filter segments by etching, either dry etching or wet etching can be applied. Dry etching is a method of etching a material with a reactive gas (etching gas), ions, or radicals. In contrast, wet etching is a method of etching a material with a liquid. Wet etching with an acid or alkali is preferable in consideration of manufacturing costs. On the other hand, dry etching, which is suitable for fine processing, is preferable when reproducibility of unevenness formation is taken into consideration.

Dry etching includes a method of exposing a material to a reactive gas (reactive gas etching), and reactive ion etching in which gas is ionized or radicalized by plasma to etch.

There are various types of dry etching equipment for reactive ion etching. In either method, the device configuration is generally the same. That is, in a chamber maintained at a required vacuum pressure, an electromagnetic wave or the like is applied to the etching gas to turn the gas into plasma. At the same time, a high frequency voltage is applied to the cathode on which the sample substrate is placed in the chamber. As a result, ion species and radical species in the plasma are accelerated toward and collide with the sample, causing sputtering by the ions and chemical reaction of the etching gas at the same time, thereby performing microfabrication of the sample.

In this embodiment, after the pattern is formed by the above-described steps, the pattern can be etched directly as it is. Moreover, after forming a resist pattern serving as a mask on the colored pattern using a photolithographic technique, the colored pattern portion exposed therefrom may be subjected to an etching treatment. According to this method, it is possible to select a colored pattern of a desired color from among a plurality of colored patterns to provide unevenness, and furthermore, it is possible to provide unevenness to a desired degree at a desired location. be.

At the time of development, an aqueous solution such as sodium carbonate or sodium hydroxide is used as an alkaline developer, and an organic alkali such as dimethylbenzylamine or triethanolamine can also be used. Moreover, an antifoaming agent or a surfactant can be added to the developer. In order to increase the UV exposure sensitivity, after coating and drying the resist, a water-soluble or alkaline water-soluble resin such as polyvinyl alcohol or water-soluble acrylic resin is coated and dried to form a film that prevents polymerization inhibition by oxygen. , UV exposure can also be performed.

The near-infrared cut filter of the present specification can be manufactured by an electrodeposition method, a transfer method, an inkjet method, or the like, in addition to the above methods. The electrodeposition method is a method of manufacturing a color filter by using a transparent conductive film formed on a substrate to electrodeposit each color filter segment on the transparent conductive film by electrophoresis of colloidal particles. The transfer method is a method in which filter segments are formed in advance on the surface of a removable transfer base sheet, and the filter segments are transferred to a desired substrate.

The near-infrared cut filter of the present specification has a wide viewing angle and excellent near-infrared cut ability. In addition, it has little absorption in the visible region (400 nm to 750 nm), excellent near-infrared absorptivity, and excellent durability such as heat resistance and light resistance. Therefore, it is useful for visibility correction of a solid-state imaging device such as a CCD of a camera module or a CMOS image sensor. In particular, digital still cameras, mobile phone cameras, digital video cameras, PC cameras, surveillance cameras, night vision cameras, automobile cameras, televisions, car navigation systems, personal digital assistants, personal computers, video games, portable game machines, fingerprint authentication systems, Useful for digital music players and the like. Moreover, depending on other materials and filters to be combined, it can be used not only as a near-infrared cut filter, but also as an IR pass filter, a band pass filter, and the like. Among others, it can be suitably used as a filter that transmits near-infrared light having a specific wavelength or later.

<Filter that transmits near-infrared light after a specific wavelength>
As an embodiment of the near-infrared cut filter, a filter that transmits near-infrared light having a specific wavelength or later will be described.
The filter that transmits near-infrared light above a certain wavelength absorbs and cuts only near-infrared light with a short wavelength around 700 to 900nm, which is possessed by the squarylium pigment, and transmits almost all of the region above 920nm. Utilizing the characteristics, it also contains a visible light absorbing dye. As a result, the filter absorbs the entire region of 400 to 900 nm and transmits near-infrared light of 920 nm and beyond. The transmitted wavelength in the near-infrared region can be adjusted to about 880 nm to 960 nm by changing the type of visible light absorbing dye.

The transmittance of the filter over the entire region of 400 nm to 850 nm is preferably 20% or less. 10% or less is more preferable, and 5% or less is even more preferable.

The near-infrared transmittance of the filter at 940 nm is preferably 65% or more, more preferably 75% or more, and even more preferably 90% or more.

An example of an embodiment of the filter is a filter that absorbs the entire region from 400 nm to a specific wavelength (specifically, 900 nm, etc.) by containing both a near-infrared absorbing dye and a visible light absorbing dye in one layer. is. Another example of the embodiment is, for example, two or more layers of a near-infrared absorbing filter containing a near-infrared absorbing dye and a visible light absorbing filter containing a visible light absorbing dye, from 400 nm to a specific wavelength (specifically is a filter that absorbs the entire region, such as 900 nm. Among these, when one dispersion contains both a near-infrared absorbing dye and a visible light absorbing dye, it is preferable from the viewpoint of avoiding the occurrence of aggregation, thickening, and the like. In the other example, for example, the solid-state imaging device can be configured such that only the second filter acts on a certain pixel, and only the first and second filters act on a certain pixel. There is an advantage that a solid-state imaging device can be formed that can recognize images in a plurality of wavelength regions at once, such as pixels that detect all external light and pixels that detect only near-infrared light after a specific wavelength.

The filter can be mixed with known near-infrared light absorbing dyes in addition to the squarylium dyes of this specification. As the near-infrared light absorbing dye, squarylium dyes described in JP-A-2010-180308 and JP-A-2018-87939 are preferable because they can improve the transmittance around 940 nm.

The visible light absorbing colorant is preferably a pigment or dye, more preferably a pigment. The visible light-absorbing dye is preferably adjusted to black, gray, or a color close thereto by combining a single colorant or a plurality of colorants.

The pigment is preferably an organic pigment. Pigments are, for example, Color Index (C.I.) PigmentYellow 1, 2, 3, 4, 5, 6, 10, 11, 12, 13, 14, 15, 16, 17, 18, 20, 24, 31, 32 , 34, 35, 35: 1, 36, 36: 1, 37, 37: 1, 40, 42, 43, 53, 55, 60, 61, 62, 63, 65, 73, 74, 77, 81, 83 , 86, 93, 94, 95, 97, 98, 100, 101, 104, 106, 108, 109, 110, 113, 114, 115, 116, 117, 118, 119, 120, 123, 125, 126, 127 , 128, 129, 137, 138, 139, 147, 148, 150, 151, 152, 153, 154, 155, 156, 161, 162, 164, 166, 167, 168, 169, 170, 171, 172, 173 , 174, 175, 176, 177, 179, 180, 181, 182, 185, 187, 188, 193, 194, 199, 213, 214, etc. (above, yellow pigment),
C. I. Pigment Orange 2, 5, 13, 16, 17: 1, 31, 34, 36, 38, 43, 46, 48, 49, 51, 52, 55, 59, 60, 61, 62, 64, 71, 73, etc. (above , orange pigment),
C. I. Pigment Red 1, 2, 3, 4, 5, 6, 7, 9, 10, 14, 17, 22, 23, 31, 38, 41, 48: 1, 48: 2, 48: 3, 48: 4, 49, 49:1, 49:2, 52:1, 52:2, 53:1, 57:1, 60:1, 63:1, 66, 67, 81:1, 81:2, 81:3, 83, 88, 90, 105, 112, 119, 122, 123, 144, 146, 149, 150, 155, 166, 168, 169, 170, 171, 172, 175, 176, 177, 178, 179, 184, 185, 187, 188, 190, 200, 202, 206, 207, 208, 209, 210, 216, 220, 224, 226, 242, 246, 254, 255, 264, 270, 272, 279, 291, etc. pigment),
C. I. Pigment Green 7, 10, 36, 37, 58, 59, 62, 63, etc. (above, green pigment),
C. I. Pigment Violet 1, 19, 23, 27, 32, 37, 42, etc. (above, purple pigment),
C. I. Pigment Blue 1, 2, 15, 15: 1, 15: 2, 15: 3, 15: 4, 15: 6, 16, 22, 60, 64, 66, 79, 80 etc. (above, blue pigment),

The dye is not particularly limited, and known dyes for color filters can be used. Chemical structures include pyrazole azo, anilinoazo, triphenylmethane, anthraquinone, anthrapyridone, benzylidene, oxonol, pyrazolotriazole azo, pyridone azo, cyanine, phenothiazine, pyrrolopyrazole azomethine, Dyes such as xathane-based, phthalocyanine-based, benzopyran-based, indigo-based, and pyrromethene-based dyes can be used.

Dyes include, for example, acid dyes, direct dyes, basic dyes, mordant dyes, acid mordant dyes, azoic dyes, disperse dyes, oil-soluble dyes, and food dyes, and derivatives thereof. Among these, acid dyes and derivatives thereof are preferred.

Acid dyes are, for example, acidalizarinvioletN, acidblue 1, 7, 9, 15, 18, 23, 25, 27, 29, 40 to 45, 62, 70, 74, 80, 83, 86, 87, 90, 92, 103, 112,113,120,129,138,147,158,171,182,192,243,324:1, acidchromevioletK, acidFuchsin; acidgreen1,3,5,9,16,25,27,50, acidrange6,7, 8, 10, 12, 50, 51, 52, 56, 63, 74, 95, acid red 1, 4, 8, 14, 17, 18, 26, 27, 29, 31, 34, 35, 37, 42, 44, 50,51,52,57,66,73,80,87,88,91,92,94,97,103,111,114,129,133,134,138,143,145,150,151,158, 176, 183, 198, 211, 215, 216, 217, 249, 252, 257, 260, 266, 274, acid violet 6B, 7, 9, 17, 19, acid yellow 1, 3, 7, 9, 11, 17, 23, 25, 29, 34, 36, 42, 54, 72, 73, 76, 79, 98, 99, 111, 112, 114, 116, 184, 243, FoodYellow3, etc.

In addition, azo, xanthene and phthalocyanine acid dyes, C.I. I. Solvent Blue 44, 38; C.I. I. Acid dyes such as Solventorange 45; Rhodamine B and Rhodamine 110, and derivatives thereof.

Acid dyes are triarylmethane, anthraquinone, azomethine, benzylidene, oxonol, cyanine, phenothiazine, pyrrolopyrazole, azomethine, xanthene, phthalocyanine, benzopyran, indigo, and pyrazole dyes. Examples include azo, anilinoazo, pyrazolotriazole azo, pyridone azo, and anthrapyridone pyrromethene. Pigments and dyes can be used in combination.

The visible light absorbing pigment preferably contains two or more selected from red colorants, yellow colorants, blue colorants, and violet colorants. Moreover, it is more preferable that the blue colorant is essential and the other one is selected from a red colorant, a yellow colorant and a purple colorant.
Preferred embodiments (1) to (3) are described below.
(1) A mode containing a red colorant, a yellow colorant, a blue colorant, and a purple colorant.
(2) Embodiment containing red, yellow and blue colorants (3) Embodiment containing yellow, blue and purple colorants.

In the embodiment (1) above, C.I. I. Pigment Red 254, C.I. I. Pigment Yellow 139, C.I. I. Pigment Blue 15:6 and C.I. I. Pigment Violet 23 is preferred.
In the above aspect (2), C.I. is used as the red pigment. I. Pigment Red 254, C.I. I. Pigment Yellow 139, C.I. I. Pigment Blue 15:6 is preferred.
In the above embodiment (3), C.I. is used as the yellow pigment. I. Pigment Yellow 139, C.I. I. Pigment Blue 15:6, C.I. I. Pigment Violet 23 can be mentioned. The ratio of the pigment is preferably the ratio disclosed in JP-A-2017-142372.

A black colorant can be used as the visible light absorbing colorant. The black colorant is preferably an organic pigment. Examples of black colorants include bisbenzofuranone compounds, azomethine compounds, perylene compounds, azo compounds and the like.

The bisbenzofuranone compound may be either a pigment or a dye, preferably a pigment. Bisbenzofuranone compounds are described, for example, in Japanese Patent Publication No. 2010-534726, Japanese Patent Publication No. 2012-515233, Japanese Patent Publication No. 2012-515234, and the like. Examples of commercially available products include "IRGAPHORBK" manufactured by BASF.

Azomethine pigments are described in JP-A-1-170601, JP-A-2-34664, etc. Commercially available products include, for example, "Chromofine Black A1103" manufactured by Dainichiseika Co., Ltd.

The visible light absorbing colorant can be appropriately selected from black colorants and non-black colorants.

The addition amount of the near-infrared light absorbing dye and the visible light absorbing dye for realizing a filter that transmits near-infrared light of a specific wavelength or later can be appropriately adjusted so as to achieve the above spectral target.

<Solid-state image sensor>
The solid-state imaging device of the present specification preferably has a near-infrared cut filter. A solid-state imaging device includes a plurality of photoelectric conversion elements that receive an optical image from an object and convert incident light into electrical signals. The types of photoelectric conversion elements are roughly classified into a CCD (charge coupled device) type and a CMOS (complementary metal oxide semiconductor) type. In addition, there are two types of photoelectric conversion element arrays: a linear sensor (line sensor) in which photoelectric conversion elements are arranged in a single row, and an area sensor (area sensor) in which photoelectric conversion elements are arranged two-dimensionally vertically and horizontally. It is divided into In any sensor, the greater the number of photoelectric conversion elements (the number of pixels), the more precise the captured image tends to be.

In addition, a color sensor that enables obtaining color information of an object by providing various color filters that transmit light of a specific wavelength on the path of light incident on the photoelectric conversion element is also widely used. The color of the color filter is a three primary color system composed of three hues of red (R), blue (B), and green (G), or cyan (C), magenta (M), and yellow. A complementary color system composed of three (Y) hues is generally used.

EXAMPLES The present invention will be described in more detail with reference to examples below, but the present invention is not limited to the following examples. In the examples and comparative examples, "part" means "mass part" and "%" means "mass%". Also, "PGMAc" is propylene glycol monomethyl ether acetate.

(Method for identifying squarylium dye)
Elemental analysis and MALDI TOF-MS spectra were used to identify the squarylium dyes. A 2400 CHN Element Analyzer manufactured by Perkin-Elmer was used for elemental analysis. The MALDI TOF-MS spectrum was obtained using a MALDI mass spectrometer autoflex III manufactured by Bruker Daltonics, and the obtained dye was identified by matching the molecular ion peak of the obtained mass spectrum with the mass number obtained by calculation. rice field.

(Powder X-ray diffraction measurement method for squarylium dye)
The powder X-ray diffraction measurement was carried out in accordance with Japanese Industrial Standards JIS K0131 (general rules for X-ray diffraction analysis) with a diffraction angle (2θ) in the range of 3° to 35°.

The measurement conditions were as follows.
X-ray diffractometer: RINT2100 manufactured by Rigaku
Sampling width: 0.02°
Scan speed: 2.0°/min
Divergence slit: 1°
Divergence longitudinal limiting slit: 10 mm
Scattering slit: 2°
Light receiving slit: 0.3mm
Tube: Cu
Tube voltage: 40kV
Tube current: 40mA

(Weight average molecular weight (Mw) of resin [A] and dispersant [B])
The weight average molecular weight (Mw) of the resin [A] and the dispersant [B] was determined by GPC (HLC-8120GPC, manufactured by Tosoh Corporation) equipped with a TSKgel column (manufactured by Tosoh Corporation) and equipped with a developing solvent. is a polystyrene equivalent weight average molecular weight (Mw) measured using THF.

(Quaternary ammonium salt value of dispersant [B])
The quaternary ammonium salt value of the dispersing agent [B] was determined by titration with a 0.1N silver nitrate aqueous solution using a 5% aqueous potassium chromate solution as an indicator, and then converted to the equivalent of potassium hydroxide. The quaternary ammonium salt value indicates the quaternary ammonium salt value of the non-volatile matter.

(Acid value of resin [A] and dispersant [B])
The acid value was determined by potentiometric titration using a 0.1N potassium hydroxide/ethanol solution. The acid value of resin [A] and dispersant [B] indicates the acid value of non-volatile matter.

(Amine value of dispersant [B])
The amine value of the dispersing agent [B] was obtained by potentiometric titration using a 0.1N hydrochloric acid aqueous solution, and then converted to the equivalent of potassium hydroxide. The amine value of the dispersant [B] indicates the amine value of the non-volatile matter.

<Preparation of squarylium dye>
[Example 1]
(Production of squarylium dye [1])
40.0 parts of 1,8-diaminonaphthalene, 38.4 parts of 2-adamantanone, and 0.087 parts of p-toluenesulfonic acid monohydrate are mixed with 400 parts of toluene, and the mixture is heated and stirred in a nitrogen gas atmosphere. and refluxed for 3 hours. Water generated during the reaction was removed from the system by azeotropic distillation. After completion of the reaction, a dark brown solid obtained by distilling toluene was extracted with acetone and purified by recrystallization from a mixed solvent of acetone and ethanol. The resulting brown solid was dissolved in a mixed solvent of 240 parts of toluene and 160 parts of n-butanol, 13.8 parts of 3,4-dihydroxy-3-cyclobutene-1,2-dione was added, and the solution was stirred in a nitrogen gas atmosphere. The mixture was heated and stirred in the medium, and the reaction was carried out under reflux for 8 hours. Water generated during the reaction was removed from the system by azeotropic distillation. After completion of the reaction, the solvent was distilled off, and 200 parts of hexane was added while stirring the resulting reaction mixture. The obtained black-brown precipitate was separated by filtration, washed with hexane, ethanol and acetone in that order, and dried under reduced pressure.
The obtained black solid was added to 550 parts of N-methylpyrrolidone and stirred at 25° C. for 3 hours. Further, 295 parts of methanol is added and stirred for 10 minutes, and the resulting black-brown precipitate is filtered off, washed with methanol, dried under reduced pressure, and 69.8 parts of squarylium dye [1] (yield : 87%). Mass spectrometry and elemental analysis by TOF-MS identified it as a squarylium dye [1]. Further, when the X-ray diffraction pattern with CuKα rays was measured, as shown in FIG. It had peaks at 0.6°, 22.4° and 26.6°.

squarylium dyes [2006.01]

[Example 2]
(Production of squarylium dye [2])
Same as the production of squarylium dye [1], except that 41.9 parts of 1-methyl-2-adamantanone was used instead of 38.4 parts of 2-adamantanone used in the production of squarylium dye [1]. operation, 69.3 parts of squarylium dye [2] (yield:
83%) was obtained. Mass spectrometry and elemental analysis by TOF-MS identified it as a squarylium dye [2]. Further, when the X-ray diffraction pattern by CuKα rays was measured, Black angles 2θ = 8.5°, 12.7°, 15.3°, 16.0°, 17.5°, 19.6°, 22. It had peaks at 4° and 26.6°.

squarylium dyes [2006.01]

[Example 3]
(Production of squarylium dye [3])
Production of squarylium dye [1] except that 55.7 parts of 1-trifluoromethyl-2-adamantanone was used instead of 38.4 parts of 2-adamantanone used in the production of squarylium dye [1]. Perform the same operation, 77.2 parts of squarylium dye [3] (
Yield: 80%). Mass spectrometry and elemental analysis by TOF-MS identified it as a squarylium dye [3]. Further, when the X-ray diffraction pattern by CuKα rays was measured, Black angles 2θ = 8.5°, 12.7°, 15.3°, 16.0°, 17.5°, 19.6°, 22. It had peaks at 4° and 26.6°.

squarylium dyes [2006.01]

[Example 4]
(Production of squarylium dye [4])
Same as the production of squarylium dye [1], except that 41.9 parts of 5-methyl-2-adamantanone was used instead of 38.4 parts of 2-adamantanone used in the production of squarylium dye [1]. The operation was carried out to obtain 68.8 parts of squarylium dye [4] (yield: 83%). Mass spectrometry and elemental analysis by TOF-MS identified it as a squarylium dye [4]. Further, when the X-ray diffraction pattern by CuKα rays was measured, Black angles 2θ = 8.5°, 12.7°, 15.3°, 16.0°, 17.5°, 19.6°, 22. It had peaks at 4° and 26.6°.

squarylium dyes [2006.01]

[Example 5]
(Production of squarylium dye [5])
Same as the production of squarylium dye [1] except that 47.2 parts of 5-chloro-2-adamantanone was used instead of 38.4 parts of 2-adamantanone used in the production of squarylium dye [1]. Operation was carried out to obtain 70.4 parts of squarylium dye [5] (yield: 80%). Mass spectrometry and elemental analysis by TOF-MS identified it as a squarylium dye [5]. Further, when the X-ray diffraction pattern by CuKα rays was measured, Black angles 2θ = 8.5°, 12.7°, 15.3°, 16.0°, 17.5°, 19.6°, 22. It had peaks at 4° and 26.6°.

squarylium dyes [2006.01]

[Example 6]
(Production of squarylium dye [6])
Same as the production of squarylium dye [1], except that 58.5 parts of 5-bromo-2-adamantanone was used instead of 38.4 parts of 2-adamantanone used in the production of squarylium dye [1]. The operation was carried out to obtain 77.8 parts of squarylium dye [6] (yield: 79%). Mass spectrometry and elemental analysis by TOF-MS identified it as a squarylium dye [6]. Further, when the X-ray diffraction pattern by CuKα rays was measured, Black angles 2θ = 8.5°, 12.7°, 15.3°, 16.0°, 17.5°, 19.6°, 22. It had peaks at 4° and 26.6°.

squarylium dyes [2006.01]

[Example 7]
(Production of squarylium dye [7])
Same as the production of squarylium dye [1] except that 42.2 parts of 5-amino-2-adamantanone was used instead of 38.4 parts of 2-adamantanone used in the production of squarylium dye [1]. The operation was carried out to obtain 71.0 parts of squarylium dye [7] (yield: 85%). Mass spectrometry and elemental analysis by TOF-MS identified it as a squarylium dye [7]. Further, when the X-ray diffraction pattern by CuKα rays was measured, Black angles 2θ = 8.5°, 12.7°, 15.3°, 16.0°, 17.5°, 19.6°, 22. It had peaks at 4° and 26.6°.

squarylium dyes [2006.01]

[Example 8]
(Production of squarylium dye [8])
Same as the production of squarylium dye [1] except that 42.4 parts of 5-hydroxy-2-adamantanone was used instead of 38.4 parts of 2-adamantanone used in the production of squarylium dye [1]. The operation was carried out to obtain 67.8 parts of squarylium dye [8] (yield: 81%). Mass spectrometry and elemental analysis by TOF-MS identified it as a squarylium dye [8]. Further, when the X-ray diffraction pattern by CuKα rays was measured, Black angles 2θ = 8.5°, 12.7°, 15.3°, 16.0°, 17.5°, 19.6°, 22. It had peaks at 4° and 26.6°.

squarylium dyes [2006.01]

[Example 9]
(Production of squarylium dye [9])
Same as the production of squarylium dye [1], except that 44.7 parts of 5-cyano-2-adamantanone was used instead of 38.4 parts of 2-adamantanone used in the production of squarylium dye [1]. The operation was carried out to obtain 68.2 parts of squarylium dye [9] (yield: 79%). Mass spectrometry and elemental analysis by TOF-MS identified it as a squarylium dye [9]. Further, when the X-ray diffraction pattern by CuKα rays was measured, Black angles 2θ = 8.5°, 12.7°, 15.3°, 16.0°, 17.5°, 19.6°, 22. It had peaks at 4° and 26.6°.

squarylium dyes [2006.01]

[Example 10]
(Production of squarylium dye [10])
Same as the production of squarylium dye [1] except that 58.8 parts of 5-sulfo-2-adamantanone was used instead of 38.4 parts of 2-adamantanone used in the production of squarylium dye [1]. The operation was carried out to obtain 80.0 parts of squarylium dye [10] (yield: 80%). Mass spectrometry and elemental analysis by TOF-MS identified it as a squarylium dye [10]. Further, when the X-ray diffraction pattern by CuKα rays was measured, Black angles 2θ = 8.5°, 12.7°, 15.3°, 16.0°, 17.5°, 19.6°, 22. It had peaks at 4° and 26.6°.

squarylium dyes [2006.01]

[Example 11]
(Production of squarylium dye [11])
Same as the production of squarylium dye [1] except that 49.9 parts of 5-nitro-2-adamantanone was used instead of 38.4 parts of 2-adamantanone used in the production of squarylium dye [1]. The operation was carried out to obtain 74.9 parts of squarylium dye [11] (yield: 82%). Mass spectrometry and elemental analysis by TOF-MS identified it as a squarylium dye [11]. Further, when the X-ray diffraction pattern by CuKα rays was measured, Black angles 2θ = 8.5°, 12.7°, 15.3°, 16.0°, 17.5°, 19.6°, 22. It had peaks at 4° and 26.6°.

squarylium dyes [2006.01]

[Example 12]
(Production of squarylium dye [12])
Production of squarylium dye [1] except that 56.0 parts of 1,3-dichloro-2-adamantanone was used instead of 38.4 parts of 2-adamantanone used in the production of squarylium dye [1]. A similar operation was performed to obtain 81.0 parts of squarylium dye [12] (yield: 84%). Mass spectrometry and elemental analysis by TOF-MS identified it as a squarylium dye [12]. Further, when the X-ray diffraction pattern by CuKα rays was measured, Black angles 2θ = 8.5°, 12.7°, 15.3°, 16.0°, 17.5°, 19.6°, 22. It had peaks at 4° and 26.6°.

squarylium dyes [2006.01]

[Example 13]
(Production of squarylium dye [13])
5-bromo-7-methyl-tricyclo[3.3.1.13,7]decan-2-one 62.1 instead of 38.4 parts of 2-adamantanone used in the preparation of squarylium dye [1] 84.9 parts of squarylium dye [13] was obtained (yield: 83%) by performing the same operation as in the production of squarylium dye [1], except that 84.9 parts of squarylium dye [13] was used. Mass spectrometry and elemental analysis by TOF-MS identified it as a squarylium dye [13]. Further, when the X-ray diffraction pattern by CuKα rays was measured, Black angles 2θ = 8.5°, 12.7°, 15.3°, 16.0°, 17.5°, 19.6°, 22. It had peaks at 4° and 26.6°.

squarylium dyes [2006.01]

[Example 14]
(Production of squarylium dye [14])
The 1,8-diaminonaphthalene used in the production of the squarylium dye [5] was changed to 4,5-diaminonaphthalene-1-sulfonic acid, and the amount of 5-chloro-2-adamantanone used was changed to 31.3 parts. 58.2 parts of squarylium dye [14] was obtained (yield: 81%) by performing the same operation as in the production of squarylium dye [5] except that Mass spectrometry and elemental analysis by TOF-MS identified it as a squarylium dye [14]. Further, when the X-ray diffraction pattern by CuKα rays was measured, Black angles 2θ = 8.5°, 12.7°, 15.3°, 16.0°, 17.5°, 19.6°, 22. It had peaks at 4° and 26.6°.

squarylium dyes [2006.01]

[Example 15]
(Production of squarylium dye [15])
The 1,8-diaminonaphthalene used in the production of the squarylium dye [5] was changed to 4,5-diaminonaphthalene-1,8-disulfonic acid, and the amount of 5-chloro-2-adamantanone used was 23.4 parts. 50.1 parts of squarylium dye [15] (yield: 79%) was obtained in the same manner as in the production of squarylium dye [5], except for changing to . Mass spectrometry and elemental analysis by TOF-MS identified it as a squarylium dye [15]. Further, when the X-ray diffraction pattern by CuKα rays was measured, Black angles 2θ = 8.5°, 12.7°, 15.3°, 16.0°, 17.5°, 19.6°, 22. It had peaks at 4° and 26.6°.

squarylium dyes [2006.01]

[Example 16]
(Production of squarylium dye [16])
The 1,8-diaminonaphthalene used in the production of the squarylium dye [5] was changed to 1,8-diamino-2,4-difluoronaphthalene, and the amount of 5-chloro-2-adamantanone used was changed to 38.4 parts. 62.0 parts of squarylium dye [16] was obtained (yield: 78%) in the same manner as in the production of squarylium dye [5], except for the changes. Mass spectrometry and elemental analysis by TOF-MS identified it as a squarylium dye [16]. Further, when the X-ray diffraction pattern by CuKα rays was measured, Black angles 2θ = 8.5°, 12.7°, 15.3°, 16.0°, 17.5°, 19.6°, 22. It had peaks at 4° and 26.6°.

squarylium dyes [2006.01]

[Example 17]
(Production of squarylium dye [17])
The 1,8-diaminonaphthalene used in the production of the squarylium dye [5] was changed to 1,8-diamino-3,6-dichloronaphthalene, and the amount of 5-chloro-2-adamantanone used was changed to 32.9 parts. 63.0 parts of squarylium dye [17] was obtained (yield: 86%) in the same manner as in the production of squarylium dye [5] except for the changes. Mass spectrometry and elemental analysis by TOF-MS identified it as a squarylium dye [17]. Further, when the X-ray diffraction pattern by CuKα rays was measured, Black angles 2θ = 8.5°, 12.7°, 15.3°, 16.0°, 17.5°, 19.6°, 22. It had peaks at 4° and 26.6°.

squarylium dyes [2006.01]

[Example 18]
(Production of squarylium dye [18])
The 1,8-diaminonaphthalene used in the production of the squarylium dye [5] was changed to 1,8-diamino-4-bromonaphthalene, and the amount of 5-chloro-2-adamantanone used was changed to 31.5 parts. Except for this, the same procedure as in the production of squarylium dye [5] was carried out to obtain 58.9 parts of squarylium dye [18] (yield: 82%). Mass spectrometry and elemental analysis by TOF-MS identified it as a squarylium dye [18]. Further, when the X-ray diffraction pattern by CuKα rays was measured, Black angles 2θ = 8.5°, 12.7°, 15.3°, 16.0°, 17.5°, 19.6°, 22. It had peaks at 4° and 26.6°.

squarylium dyes [2006.01]

Tables 1 and 2 show the results of mass spectrometry and elemental analysis of the squarylium dyes synthesized in Examples 1 to 18.

[Comparative Example 1]
(Production of squarylium dye [C-1])
The following squarylium dye [C-1] was synthesized according to JP-A-2009-91517.

Squarylium dye [C-1]

[Comparative Example 2]
(Production of squarylium dye [C-2])
The following squarylium dye [C-2] was synthesized according to JP-A-2010-106153.

Squarylium dye [C-2]

[Comparative Example 3]
(Production of squarylium dye [C-3])
The following squarylium [C-3] was synthesized according to JP-A-2009-209297.

Squarylium dye [C-3]

<Production and Evaluation of Image Forming Material>
Toners and inkjet inks are prepared as image forming materials.

<Toner production>
[Example 19] (Production of toner T1)
Using the squarylium dye [1] produced in Example 1, Toner T1 was obtained by the following method.
(1) Preparation of dispersion To 20 parts of squarylium dye [1], 70 parts of ion-exchanged water and 3 parts of sodium dodecylbenzenesulfonate (Neopelex G-15, manufactured by Kao Corporation) are added, and dispersed for 4 hours with an Eiger mill. to obtain a pigment dispersion.
(2) Preparation of polymer emulsion 320 parts of ester wax emulsion as non-volatile matter (SELOSOL R-586, manufactured by Chukyo Yushi Co., Ltd.) and 14,000 parts of ion-exchanged water are placed in a reactor, heated to 90° C., and dodecylbenzene 3 parts of sodium sulfonate, 2500 parts of styrene, 650 parts of n-butyl acrylate, 170 parts of methacrylic acid, 330 parts of 8% aqueous hydrogen peroxide solution and 330 parts of 8% aqueous ascorbic acid solution were added. The reaction was continued at 90° C. for 7 hours to obtain a polymer emulsion.
(3) Production of Toner To 150 parts of the polymer emulsion, 9.5 parts of the dispersion liquid was poured and mixed with stirring. 40 parts of a 0.5% aluminum sulfate solution was poured into this while stirring. The mixture was heated to 60° C., stirred for 2 hours, filtered, washed and dried to obtain Toner T1 of the present specification.

[Examples 20 to 36, Comparative Examples 4 to 6] (Production of toners T2 to T21)
Aggregation toners T2 to T21 were obtained in the same manner as toner T1, except that squarylium dye [1] was changed to the squarylium dye shown in Table 3.

<Evaluation of image forming material>
[Evaluation of Toner]
The following evaluations were performed using the obtained toners T1 to T21. Table 3 shows the results.
(dispersibility)
The obtained toner was sliced with a microtome to a thickness of 0.9 μm to prepare a sample. An enlarged image of the sample was observed using a transmission electron microscope to observe the dispersed state of the squarylium dye. Evaluation criteria are as follows. In addition, ⊚ to ∘ are practical levels for toner applications.
◎: Pigment aggregates are not present and the squarylium dye is extremely uniformly dispersed ○: Pigment aggregates are almost absent and the squarylium dye is uniformly dispersed △: Pigment aggregates are present , The squarylium pigment is not uniformly dispersed ×: Many pigment aggregates are present, and the squarylium pigment is not uniformly dispersed

(Invisibility and near-infrared absorption ability)
To 50 parts of the obtained toner, 0.3 part of hydrophobic silica (HDK H18, manufactured by Asahi Kasei Wacker Silicone Co., Ltd.) was added, and the entire surface was printed on high-quality paper with a size of 10 cm long x 10 cm wide by an electrophotographic printer. , to make print samples. The solid image of the print sample was measured using a reflection spectral densitometer (x-rite 939, manufactured by X-Rite Co., Ltd.). Regarding the measurement results, ΔE in the formula (I) and R in the formula (II) were obtained. Evaluation criteria are as follows. In addition, ⊚ indicates a very good level, ◯ indicates a good level, and x indicates a level not suitable for practical use.
〈Invisibility〉
◎: ΔE less than 10 ○: ΔE 10 or more, 15 or less ×: ΔE more than 15 <near infrared absorption>
◎: (100-R) 80 or more ○: (100-R) 75 or more and less than 80 ×: (100-R) less than 75

(Lightfastness (1))
A sample prepared in the same manner as the printed sample was placed in a light resistance tester ("SUNTEST CPS+" manufactured by TOYOSEIKI) and left for 24 hours under the conditions of irradiance of 47 mW/cm ² and broadband light of 300 to 800 nm. . After the end of the test, the images before and after the lightfastness test were measured using a reflection spectrodensitometer (x-rite 939, manufactured by X-Rite Co., Ltd.) to obtain R in formula (II). The residual rate for (100-R) before light irradiation was determined, and the light resistance was evaluated according to the following criteria. In addition, calculation of the survival rate was calculated using the following formula. ⊚ to ◯ are practical levels for toner applications.
Residual rate = <(100-R) after irradiation> / <(100-R) before irradiation> x 100
◎: Residual rate is 95% or more ○: Residual rate is 92.5% or more and less than 95% △: Residual rate is 90% or more and less than 92.5% ×: Residual rate is less than 90%

(Lightfastness (2))
Except for extending the standing time in the light resistance tester to 48 hours (light resistance (1)), the same procedure as (light resistance (1)) was carried out, and the evaluation was conducted in the same manner.

From the results in Table 3, the toner containing the squarylium dye of the present specification has very high dispersibility, invisibility, near-infrared absorption ability, and lightfastness. In particular, toners containing [1][5][6][12], in which X ₁ to X ₄ of the squarylium dye are hydrogen atoms or halogen atoms and R ₁ to R ₅ are hydrogen atoms, gave good results. rice field.
On the other hand, Comparative Examples 4 and 5 had particularly poor light resistance. Comparative Example 6 has good invisibility, near-infrared absorptivity, and light resistance, but is not suitable for practical use because its dispersibility is remarkably deteriorated.

<<Preparation of inkjet ink (IJ ink)>>
A dispersant and a binder were prepared for the production of the IJ ink.

(Preparation of dispersant [B-1] solution)
A reaction vessel equipped with a gas inlet tube, a thermometer, a condenser and a stirrer was charged with 93.4 parts of triethylene glycol monomethyl ether and purged with nitrogen gas. The inside of the reaction vessel is heated to 110 ° C., 35.0 parts of lauryl methacrylate, 35.0 parts of styrene, 30.0 parts of acrylic acid, and V-601 (Dimethyl 2,2'-azobis (2 -methylpropionate) (manufactured by Wako Pure Chemical Industries) 6.0 parts of the mixture was added dropwise over 2 hours to carry out a polymerization reaction. After completion of dropping, further reaction at 110° C. for 3 hours, 0.6 part of V-601 (manufactured by Wako Pure Chemical Industries, Ltd.) was added, reaction was further continued at 110° C. for 1 hour, and dispersant [B-1] was added. A solution of The weight average molecular weight (Mw) of the dispersant [B-1] was about 16,000. Furthermore, after cooling to room temperature, 37.1 parts of dimethylaminoethanol was added for neutralization. This is the amount for 100% neutralization of acrylic acid. Further, 200 parts of ion-exchanged water was added to make it aqueous. 1 g of this was sampled and dried by heating at 180° C. for 20 minutes to measure the non-volatile content, and ion-exchanged water was added so that the non-volatile content of the previously aqueous resin solution was 20%. Thus, an aqueous solution of dispersant [B-1] having a non-volatile content of 20% was obtained.

(Preparation of resin [A-1] solution)
A reaction vessel equipped with a stirrer, a thermometer, a dropping funnel, and a reflux vessel was charged with 40 parts of ion-exchanged water and 0.2 parts of Aqualon KH-10 (manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) as an anionic surfactant, Separately, 40 parts of 2-ethylhexyl acrylate, 50 parts of methyl methacrylate, 7 parts of styrene, 2 parts of dimethylacrylamide, 1 part of methacrylic acid, 53 parts of deionized water and Aqualon KH-10 as a surfactant (Daiichi Kogyo Seiyaku Co., Ltd.) An additional 1% of the pre-mixed pre-emulsion of 1.8 parts was added. After raising the internal temperature to 60° C. and sufficiently replacing with nitrogen, 10 parts of a 5% aqueous solution of potassium persulfate and 20 parts of a 1% aqueous solution of anhydrous sodium bisulfite were added to initiate polymerization. After maintaining the inside of the reaction system at 60°C for 5 minutes, the remainder of the pre-emulsion, the 5% aqueous solution of potassium persulfate, and the remainder of the 1% aqueous solution of anhydrous sodium bisulfite were added for 1.5 hours while maintaining the internal temperature at 60°C. The mixture was added dropwise over a period of time, and the stirring was continued for an additional 2 hours. After confirming that the conversion rate exceeded 98% by non-volatile measurement, the temperature was cooled to 30°C. Diethylaminoethanol was added to adjust the pH to 8.5, and ion-exchanged water was added to adjust the non-volatile content to 40% to obtain an aqueous dispersion of fine resin particles. The non-volatile content was obtained from the residue after baking at 150° C. for 20 minutes. The obtained resin fine particle aqueous dispersion was used as a resin [A-1] solution.

<Production of inkjet ink>
[Example 37] (Ink jet ink J1)
Using the squarylium compound [1] produced in Example 1, inkjet ink J1 was obtained by the following method.
(1) Preparation of Dispersion Monomers and oligomers of Example 1: 20 parts of ion-exchanged water, sodium salt of special aromatic sulfonic acid formalin condensate as a dispersant (Demol SN-B, manufactured by Kao Corporation) 2 parts were added and dispersed for 3 hours with an Eiger mill to obtain a pigment dispersion.
(2) Production of ink To 40.3 parts of each of the above dispersions, 10 parts of glycerin, 10 parts of triethylene glycol, 10 parts of triethylene glycol monobutyl ether, 0.2 parts of triethanolamine, an acetylene glycol surfactant (Olfine E1010, manufactured by Nissin Chemical Co., Ltd.) was mixed and stirred at 35° C. for 1 hour. To the remainder, ultrapure water (specific resistance of 18 MΩ·cm or more) was added to adjust the total amount to 100 parts. After that, it was filtered through a 1.0 μm filter to obtain ink J1 for inkjet of the present specification.

[Examples 38 to 54, Comparative Examples 7 to 9] (inkjet inks J2 to J21)
Inkjet inks J2 to J21 were obtained in the same manner as for inkjet ink J1, except that squarylium dye [1] was changed to the squarylium dye shown in Table 4.

[Example 55]
(Production of inkjet ink J22)
20 parts of the squarylium dye [1], 42.9 parts of the dispersant [B-1] solution, and 37.1 parts of ion-exchanged water prepared in Example 1 were pre-dispersed with a disper, and then dispersed into particles having a diameter of 0.5 mm. Using a Dyno mill with a volume of 0.6 L filled with 1800 parts of zirconia beads, main dispersion was carried out for 2 hours to obtain a dispersion.
Furthermore, 20 parts of the dispersion obtained above, 40 parts of triethylene glycol monomethyl ether, 27.5 parts of ion-exchanged water, and 12.5 parts of the resin [A-1] solution were mixed to form an ink jet ink J22. got

[Examples 56-72, Comparative Examples 10-12]
(Production of inkjet inks J23 to J42)
Inkjet inks J23 to J42 were obtained in the same manner as for inkjet ink J22, except that squarylium dye [1] was changed to the squarylium dye shown in Table 5.

[Evaluation of inkjet ink]
The following evaluations were performed using the obtained inkjet inks J1 to J42. The results are shown in Tables 4 and 5.

(Storage stability)
The resulting inkjet ink was stored in a constant temperature machine at 70° C. for 1 week, accelerated over time, and then measured for change in viscosity of the ink before and after the lapse of time. The viscosity of the ink was measured using an E-type viscometer (“ELD type viscometer” manufactured by Toki Sangyo Co., Ltd.) at 25° C. and a rotation speed of 50 rpm. Evaluation criteria are as follows. In addition, ⊚ to ∘ are practical levels.
◎: Rate of change is less than ±3% ○: Rate of change is ±3% or more and less than ±5% △: Rate of change is ±5% or more and less than ±15% ×: Rate of change is ±15% or more

(Invisibility and near-infrared absorption ability)
The obtained ink for inkjet is packed in an ink cartridge for black ink for inkjet printer PM-A700 (trade name, manufactured by EPSON) and applied to photo glossy paper (PM photo paper <glossy> manufactured by EPSON (KA420PSK, EPSON). (trade name) was printed with a color setting of "black" to prepare a print sample with an adhesion amount of 4 g/ ^m2 . -rite 939) to obtain ΔE in formula (I) and R in formula (II).In addition, ◎ is a very good level, ○ is a good level, and × is practical This is an unsuitable level.The evaluation criteria are as follows.
〈Invisibility〉
◎: ΔE less than 10 ○: ΔE 10 or more, 15 or less ×: ΔE more than 15 <near infrared absorption>
◎: (100-R) 80 or more ○: (100-R) 75 or more and less than 80 ×: (100-R) less than 75

(Lightfastness (1))
A sample prepared in the same manner as the printed sample was placed in a light resistance tester ("SUNTEST CPS+" manufactured by TOYOSEIKI) and left for 24 hours under the conditions of an irradiance of 47 mW/cm ² and broadband light of 300 to 800 nm. After the end of the test, the images before and after the lightfastness test were measured using a reflection spectrodensitometer (x-rite 939, manufactured by X-Rite Co., Ltd.) to obtain R in formula (II). The residual rate was determined with respect to that before light irradiation, and the light resistance was evaluated according to the following criteria. In addition, calculation of the survival rate was calculated using the following formula.
Residual rate = <(100-R) after irradiation> / <(100-R) before irradiation> x 100
◎: Residual rate is 95% or more ○: Residual rate is 92.5% or more and less than 95% △: Residual rate is 90% or more and less than 92.5% ×: Residual rate is less than 90%

(Lightfastness (2))
Except for extending the standing time in the light resistance tester to 48 hours (light resistance (1)), the same procedure as (light resistance (1)) was carried out, and the evaluation was conducted in the same manner.

The results in Tables 4 and 5 show that the inkjet ink containing the squarylium dye [A] of the present specification has very high dispersibility, invisibility, near-infrared absorption ability, and lightfastness. In particular, ink-jet inks containing [1][5][6][12] in which X ₁ to X ₄ of the squarylium dye are hydrogen atoms or halogen atoms and R ₁ to R ₅ are hydrogen atoms give good results. there were.
On the other hand, Comparative Examples 7, 8, 10, and 11 had particularly poor light resistance. Moreover, Comparative Examples 9 and 12 are not suitable for practical use because they have excellent invisibility, near-infrared absorption ability, and light resistance, but their storage stability is remarkably deteriorated.

It can be said that the image-forming material thus prepared has very excellent spectral characteristics because it has little absorption in the visible region (400 nm to 750 nm) and has excellent near-infrared absorption ability. Furthermore, since it is excellent in light resistance and hardly aggregates, it is excellent in dispersibility as a toner and storage stability as an ink for ink jet. Therefore, it is excellent as an image forming material for recording invisible information.

≪Preparation of near-infrared absorption composition≫
<Preparation of resin [A] (binder resin) solution>
(Preparation of Binder Resin [A-2] Solution): Random Copolymer A separable four-necked flask was equipped with a thermometer, a cooling tube, a nitrogen gas inlet tube, and a stirring device. After raising the temperature to ° C. and replacing the inside of the reaction vessel with nitrogen, 12.4 parts of n-butyl methacrylate, 4.6 parts of 2-hydroxyethyl methacrylate, 4.3 parts of methacrylic acid, and paracumylphenol ethylene oxide modification were added from the dropping tube. Acrylate ("Aronix M110" manufactured by Toagosei Co., Ltd.) 7.3 parts (n-butyl methacrylate/2-hydroxyethyl methacrylate/methacrylic acid/paracumylphenol ethylene oxide-modified acrylate weight ratio 10.5/15.5/17. 1/25.0) and 0.7 parts of 2,2'-azobisisobutyronitrile was added dropwise over 2 hours. After the dropwise addition, the reaction was continued for 3 hours to obtain an acrylic resin solution having an acid value of 110 mgKOH/g and a weight average molecular weight (Mw) of 10,000. After cooling to room temperature, about 2 g of the resin solution was sampled and dried by heating at 180°C for 20 minutes to measure the nonvolatile content. A binder resin [A-2] solution was prepared by adding ether acetate.

<Preparation of dispersant [B]>
(Dispersant [B-2] solution): tertiary amino group-containing graft copolymer Propylene glycol monomethyl ether acetate (hereinafter also referred to as PGMAc) was added to a reaction vessel equipped with a gas inlet tube, a thermometer, a condenser, and a stirrer. 150 parts of n-butyl tacrylate and 100 parts of n-butyl tacrylate were charged, and the atmosphere was purged with nitrogen gas. The inside of the reaction vessel was heated to 80° C., and a solution of 0.5 parts of 2,2′-azobisisobutyronitrile dissolved in 4 parts of 2-mercaptoethanol was added and reacted for 10 hours. It was confirmed by measurement of the nonvolatile content that 95% of the reaction had occurred, and a reaction product (dispersant 1a) having a number average molecular weight of 3,900 and a weight average molecular weight of 7,900 was obtained.
7.9 parts of 2-methacryloyloxyethyl isocyanate, 0.05 parts of methyldibutyltin dilaurate, and 0.05 parts of methylhydroquinone were added to the above reaction product, and the reaction vessel was heated to 100° C. and reacted for 4 hours. . After that, it was cooled to 40° C. to obtain a reaction product (resin type dispersant 1b solution).
122 parts of PGMAc was charged into a reactor equipped with a gas inlet tube, a condenser, a stirring blade, and a thermometer, and the temperature was raised to 100° C. while purging with nitrogen. 150 parts of the above reaction product, pentamethylpiperidyl methacrylate (manufactured by ADEKA Co., Ltd., Adekastab LA-82), 10 parts of hydroxyethyl methacrylate, and 2,2′-azobis(2,4-dimethylbutyronitrile) were added to a dropping tank. After 4 parts were prepared and stirred until uniform, the mixture was added dropwise to the reactor over 2 hours, and the reaction was continued at the same temperature for 3 hours. In this way, the amine value per non-volatile content is 42 mgKOH / g, the non-volatile content of the weight average molecular weight (Mw) 23,500 is 40 mass% poly (meth) acrylate skeleton, dispersant having a tertiary amino group A [B-2] solution was obtained.

(Dispersant [B-3] solution): tertiary amino group-containing block copolymer Into a reaction apparatus equipped with a gas inlet tube, a condenser, a stirring blade, and a thermometer, 60 parts of methyl methacrylate and 20 parts of n-butyl methacrylate were added. and 13.2 parts of tetramethylethylenediamine were charged, and the mixture was stirred at 50° C. for 1 hour while nitrogen was passed through, and the inside of the system was replaced with nitrogen. Next, 9.3 parts of ethyl bromoisobutyrate, 5.6 parts of cuprous chloride, and 133 parts of PGMAc were charged, and the temperature was raised to 110° C. under a nitrogen stream to initiate polymerization of the first block. After polymerization for 4 hours, the polymerization solution was sampled and the non-volatile content was measured, and it was confirmed that the polymerization conversion rate was 98% or more in terms of the non-volatile content.
Next, 61 parts of PGMAc and 20 parts of dimethylaminoethyl methacrylate (hereinafter also referred to as DM) as a second block monomer were added to this reactor, and the reaction was continued by stirring while maintaining the temperature at 110°C under a nitrogen atmosphere. . Two hours after the addition of dimethylaminoethyl methacrylate, the polymerization solution was sampled and the nonvolatile content was measured to confirm that the polymerization conversion rate of the second block was 98% or more in terms of the nonvolatile content. Polymerization was stopped by cooling.
Propylene glycol monomethyl ether acetate was added to the previously synthesized block copolymer solution so that the non-volatile content was 40% by mass. In this way, the amine value per nonvolatile content is 71.4 mgKOH / g, the weight average molecular weight (Mw) is 9,900, and the nonvolatile content is a poly (meth) acrylate skeleton of 40% by mass, and has a tertiary amino group. A dispersant [B-3] solution was obtained.

(Dispersant [B-4] solution): quaternary ammonium base-containing block copolymer Gas introduction pipe, condenser, stirring blade, and a reactor equipped with a thermometer, 60 parts of methyl methacrylate, 20 parts of n-butyl methacrylate and 13.2 parts of tetramethylethylenediamine were charged, and the mixture was stirred at 50° C. for 1 hour while nitrogen was passed through, and the inside of the system was replaced with nitrogen. Next, 9.3 parts of ethyl bromoisobutyrate, 5.6 parts of cuprous chloride, and 133 parts of PGMAc were charged, and the temperature was raised to 110° C. under a nitrogen stream to initiate polymerization of the first block. After polymerization for 4 hours, the polymerization solution was sampled and the non-volatile content was measured, and it was confirmed that the polymerization conversion rate was 98% or more in terms of the non-volatile content.
Next, 61 parts of PGMAc and 25.6 parts of an aqueous solution of methacryloyloxyethyltrimethylammonium chloride (“Acryester DMC78” manufactured by Mitsubishi Rayon Co., Ltd.) as a second block monomer are added to the reactor, and the temperature is maintained at 110° C. under a nitrogen atmosphere. The reaction was continued while stirring. Two hours after the addition of methacryloyloxyethyltrimethylammonium chloride, the polymerization solution was sampled and the nonvolatile content was measured. Polymerization was terminated by cooling to room temperature.
Propylene glycol monomethyl ether acetate was added to the previously synthesized block copolymer solution so that the non-volatile content was 40% by mass. In this way, the quaternary ammonium salt value per non-volatile content is 29.4 mgKOH / g, the weight average molecular weight (Mw) is 9,800, and the non-volatile content is 40% by mass. A dispersant [B-4] solution with a base was obtained.

(Dispersant [B-5] solution) Acidic resin-type dispersant 50 parts of methyl methacrylate, 50 parts of n-butyl methacrylate, and 45.4 parts of PGMAc were charged into a reaction vessel equipped with a gas inlet tube, thermometer, condenser, and stirrer. , was replaced with nitrogen gas. The inside of the reaction vessel was heated to 70° C., 6 parts of 3-mercapto-1,2-propanediol was added, and 0.12 part of AIBN (azobisisobutyronitrile) was further added and reacted for 12 hours. It was confirmed by measuring the non-volatile content that 95% had reacted. Next, add 9.7 parts of pyromellitic anhydride, 70.3 parts of PGMAc, and 0.20 parts of DBU (1,8-diazabicyclo-[5.4.0]-7-undecene) as a catalyst, and heat at 120°C. was reacted for 7 hours. It was confirmed by acid value measurement that 98% or more of the acid anhydride was half-esterified, and the reaction was terminated. PGMAc was added to adjust the non-volatile content to 50%. Thus, a dispersant [B-5] solution having an acid value per non-volatile content of 43 mgKOH/g, a weight average molecular weight (Mw) of 9,000, a poly(meth)acrylate skeleton and an aromatic carboxyl group was obtained. rice field.

(Dispersant [B-6] solution) Acidic resin-type dispersant Into a reaction vessel equipped with a gas inlet tube, a thermometer, a condenser and a stirrer, 6 parts of 3-mercapto-1,2-propanediol and pyromellitic anhydride were added. 9.7 parts of monobutyltin oxide, 0.01 part of monobutyltin oxide and 88.9 parts of PGMAc were charged, and the mixture was purged with nitrogen gas. The inside of the reaction vessel was heated to 100° C. and reacted for 7 hours. After confirming that 98% or more of the acid anhydride is half-esterified by acid value measurement, the temperature in the system is cooled to 70 ° C., 50 parts of methyl methacrylate, 30 parts of n-butyl methacrylate, and hydroxymethyl 20 parts of methacrylate was charged, 0.12 parts of AIBN and 26.8 parts of PGMAc were added and reacted for 10 hours. After confirming that the polymerization had progressed by 95% by measuring the non-volatile content, the reaction was terminated. PGMAc was added to adjust the nonvolatile content to 50%, and the dispersant [ B-6] solution was obtained.

(Dispersant [B-7] solution)
Disperbyk-168 (manufactured by BYK-Chemie Japan: non-volatile content 30%)

(Dispersant [B-8] solution)
BYK-P104 (manufactured by BYK-Chemie Japan: non-volatile content 50%)

(Dispersant [B-9] solution)
Disperbyk-171 (manufactured by BYK-Chemie Japan: non-volatile content 39.5%)

[Preparation of tertiary amino group and quaternary ammonium base-containing dispersant]
(Preparation of Dispersant [B-10] Solution): Block Copolymer Into a reactor equipped with a gas inlet tube, a condenser, a stirring blade, and a thermometer, 44.7 parts of methyl methacrylate and 14.9 parts of n-butyl methacrylate were added. and 13.2 parts of tetramethylethylenediamine were charged, and the mixture was stirred at 50° C. for 1 hour while flowing nitrogen, and the inside of the system was replaced with nitrogen. Next, 2.6 parts of ethyl bromoisobutyrate, 5.6 parts of cuprous chloride, and 133 parts of propylene glycol monomethyl ether acetate (hereinafter referred to as PGMAc) are charged, and the temperature is raised to 110° C. under a nitrogen stream to form the first block. started to polymerize. After polymerization for 4 hours, the polymerization solution was sampled and the non-volatile content was measured, and it was confirmed that the polymerization conversion rate was 98% or more in terms of the non-volatile content.
Next, 61 parts of PGMAc and 33.6 parts of dimethylaminoethyl methacrylate (hereinafter referred to as DM) as a second block monomer were added to the reactor, and the reaction was continued by stirring while maintaining the temperature at 110°C under a nitrogen atmosphere. . Two hours after the addition of dimethylaminoethyl methacrylate, the polymerization solution was sampled and the nonvolatile content was measured, and it was confirmed that the polymerization conversion rate of the second block was 98% or more in terms of the nonvolatile content. Further, 6.8 parts of benzyl chloride was added to the reactor, stirred for 3 hours while maintaining the temperature at 110° C. under a nitrogen atmosphere, and then cooled.
PGMAc was added to the previously synthesized block copolymer solution so that the non-volatile content was 40% by mass. Thus, a dispersant [B-10] having an amine value per non-volatile content of 90 mg KOH / g, a quaternary ammonium salt value of 30 mg KOH / g, a weight average molecular weight (Mw) of 9,800, and a non-volatile content of 40% by mass A solution was obtained.

(Preparation of dispersant [B-11] solution): block copolymer In a reactor equipped with a gas inlet tube, a condenser, a stirring blade, and a thermometer, 47.8 parts of methyl methacrylate and 15.9 parts of n-butyl methacrylate were added. and 13.2 parts of tetramethylethylenediamine were charged, and the mixture was stirred at 50° C. for 1 hour while flowing nitrogen, and the inside of the system was replaced with nitrogen. Next, 2.6 parts of ethyl bromoisobutyrate, 5.6 parts of cuprous chloride, and 133 parts of PGMAc were charged, and the temperature was raised to 110° C. under a nitrogen stream to initiate polymerization of the first block. After polymerization for 4 hours, the polymerization solution was sampled and the non-volatile content was measured, and it was confirmed that the polymerization conversion rate was 98% or more in terms of the non-volatile content.
Next, 61 parts of PGMAc, 25.2 parts of DM as a second block monomer, and 13.8 parts of an aqueous solution of methacryloyloxyethyltrimethylammonium chloride ("Acryester DMC80" manufactured by Mitsubishi Rayon Co., Ltd., non-volatile content 80%) were added to the reactor. The mixture was stirred while maintaining the temperature at 110° C. under a nitrogen atmosphere, and the reaction was continued. After 2 hours, the polymerization solution was sampled and the non-volatile content was measured to confirm that the polymerization conversion rate of the second block was 98% or more in terms of the non-volatile content, and the reaction solution was cooled to room temperature to stop the polymerization. did.
PGMAc was added to the previously synthesized block copolymer solution so that the non-volatile content was 40% by mass. Thus, a dispersant [B-11] having an amine value per non-volatile content of 90 mg KOH / g, a quaternary ammonium salt value of 30 mg KOH / g, a weight average molecular weight (Mw) of 9,800, and a non-volatile content of 40% by mass A solution was obtained.

(Preparation of dispersant [B-12] solution): block copolymer In a reaction vessel equipped with a gas inlet pipe, a condenser, a stirring blade, and a thermometer, 39.4 parts of methyl methacrylate and 13.1 parts of n-butyl methacrylate were added. and 13.2 parts of tetramethylethylenediamine were charged, and the mixture was stirred at 50° C. for 1 hour while flowing nitrogen, and the inside of the system was replaced with nitrogen. Next, 2.6 parts of ethyl bromoisobutyrate, 5.6 parts of cuprous chloride, and 133 parts of PGMAc were charged, and the temperature was raised to 110° C. under a nitrogen stream to initiate polymerization of the first block. After polymerization for 4 hours, the polymerization solution was sampled and the non-volatile content was measured, and it was confirmed that the polymerization conversion rate was 98% or more in terms of the non-volatile content.
Next, 61 parts of PGMAc, 36.4 parts of DM as the second block monomer, and 13.8 parts of an aqueous solution of methacryloyloxyethyltrimethylammonium chloride (“Acryester DMC80” manufactured by Mitsubishi Rayon Co., Ltd., non-volatile content of 80%) were added to the reactor. The mixture was stirred while maintaining the temperature at 110° C. under a nitrogen atmosphere, and the reaction was continued. After 2 hours, the polymerization solution was sampled and the non-volatile content was measured to confirm that the polymerization conversion rate of the second block was 98% or more in terms of the non-volatile content, and the reaction solution was cooled to room temperature to stop the polymerization. did.
PGMAc was added to the previously synthesized block copolymer solution so that the non-volatile content was 40% by mass. Thus, a dispersant [B-12] having an amine value per non-volatile content of 130 mg KOH / g, a quaternary ammonium salt value of 30 mg KOH / g, a weight average molecular weight (Mw) of 9,800, and a non-volatile content of 40% by mass A solution was obtained.

(Preparation of dispersant [B-13] solution): block copolymer Into a reactor equipped with a gas inlet tube, a condenser, a stirring blade, and a thermometer, 40.2 parts of methyl methacrylate and 13.4 parts of n-butyl methacrylate were added. and 13.2 parts of tetramethylethylenediamine were charged, and the mixture was stirred at 50° C. for 1 hour while flowing nitrogen, and the inside of the system was replaced with nitrogen. Next, 2.6 parts of ethyl bromoisobutyrate, 5.6 parts of cuprous chloride, and 133 parts of propylene glycol monomethyl ether acetate (hereinafter referred to as PGMAc) are charged, and the temperature is raised to 110° C. under a nitrogen stream to form the first block. started to polymerize. After polymerization for 4 hours, the polymerization solution was sampled and the non-volatile content was measured, and it was confirmed that the polymerization conversion rate was 98% or more in terms of the non-volatile content.
Next, 61 parts of PGMAc and 39.6 parts of diethylaminoethyl methacrylate (hereinafter referred to as DE) as a second block monomer were added to the reactor, and the mixture was stirred while maintaining the temperature at 110° C. under a nitrogen atmosphere to continue the reaction. After 2 hours from the addition of diethylaminoethyl methacrylate, the polymerization solution was sampled and non-volatile content was measured, and it was confirmed that the polymerization conversion rate of the second block was 98% or more in terms of non-volatile content. Further, 6.8 parts of benzyl chloride was added to the reactor, stirred for 3 hours while maintaining the temperature at 110° C. under a nitrogen atmosphere, and then cooled.
PGMAc was added to the previously synthesized block copolymer solution so that the non-volatile content was 40% by mass. Thus, a dispersant [B-13] having an amine value per non-volatile content of 90 mg KOH / g, a quaternary ammonium salt value of 30 mg KOH / g, a weight average molecular weight (Mw) of 9,800, and a non-volatile content of 40% by mass A solution was obtained.

(Preparation of dispersant [B-14] solution): block copolymer Into a reactor equipped with a gas inlet pipe, a condenser, a stirring blade, and a thermometer, 42.6 parts of methyl methacrylate and 14.2 parts of n-butyl methacrylate were added. and 13.2 parts of tetramethylethylenediamine were charged, and the mixture was stirred at 50° C. for 1 hour while flowing nitrogen, and the inside of the system was replaced with nitrogen. Next, 2.6 parts of ethyl bromoisobutyrate, 5.6 parts of cuprous chloride, and 133 parts of propylene glycol monomethyl ether acetate (hereinafter referred to as PGMAc) are charged, and the temperature is raised to 110° C. under a nitrogen stream to form the first block. started to polymerize. After polymerization for 4 hours, the polymerization solution was sampled and the non-volatile content was measured, and it was confirmed that the polymerization conversion rate was 98% or more in terms of the non-volatile content.
Next, 61 parts of PGMAc and 36.4 parts of dimethylaminopropyl methacrylamide (hereinafter referred to as DMAPMA) as a second block monomer are added to the reactor, and the reaction is continued by stirring while maintaining the temperature at 110°C under a nitrogen atmosphere. did. Two hours after the addition of dimethylaminopropyl methacrylamide, the polymerization solution was sampled and the non-volatile content was measured, and it was confirmed that the polymerization conversion rate of the second block was 98% or more in terms of the non-volatile content. Further, 6.8 parts of benzyl chloride was added to the reactor, stirred for 3 hours while maintaining the temperature at 110° C. under a nitrogen atmosphere, and then cooled.
PGMAc was added to the previously synthesized block copolymer solution so that the non-volatile content was 40% by mass. Thus, a dispersant [B-14] having an amine value per nonvolatile content of 90 mgKOH/g, a quaternary ammonium salt value of 30 mgKOH/g, a weight average molecular weight (Mw) of 9,800, and a nonvolatile content of 40% by mass A solution was obtained.

(Preparation of dispersant [B-15] solution): block copolymer Into a reactor equipped with a gas inlet pipe, a condenser, a stirring blade, and a thermometer, 39.6 parts of methyl methacrylate and 13.2 parts of n-butyl methacrylate were added. and 13.2 parts of tetramethylethylenediamine were charged, and the mixture was stirred at 50° C. for 1 hour while flowing nitrogen, and the inside of the system was replaced with nitrogen. Next, 2.6 parts of ethyl bromoisobutyrate, 5.6 parts of cuprous chloride, and 133 parts of PGMAc were charged, and the temperature was raised to 110° C. under a nitrogen stream to initiate polymerization of the first block. After polymerization for 4 hours, the polymerization solution was sampled and the non-volatile content was measured, and it was confirmed that the polymerization conversion rate was 98% or more in terms of the non-volatile content.
Next, in this reactor, 61 parts of PGMAc, 36.1 parts of pentamethylpiperidyl methacrylate (manufactured by ADEKA Co., Ltd., Adekastab LA-82) as a second block monomer, 13.8 parts of methacryloyloxyethyltrimethylammonium chloride aqueous solution (Mitsubishi Rayon "Acryester DMC80" manufactured by Co., Ltd., non-volatile content 80%) was added, and the reaction was continued by stirring while maintaining the temperature at 110°C under a nitrogen atmosphere. After 2 hours, the polymerization solution was sampled and the non-volatile content was measured to confirm that the polymerization conversion rate of the second block was 98% or more in terms of the non-volatile content, and the reaction solution was cooled to room temperature to stop the polymerization. did.
PGMAc was added to the previously synthesized block copolymer solution so that the non-volatile content was 40% by mass. Thus, a dispersant [B-15] having an amine value per nonvolatile content of 90 mgKOH/g, a quaternary ammonium salt value of 30 mgKOH/g, a weight average molecular weight (Mw) of 9,800, and a nonvolatile content of 40% by mass A solution was obtained.

<Production and evaluation of near-infrared absorbing composition>
[Example 73]
(Near-infrared absorbing composition (IR-1))
After uniformly stirring and mixing the mixture of the following composition, using zirconia beads with a diameter of 0.5 mm, after dispersing with an Eiger mill for 3 hours, filtering with a 0.5 μm filter, a near-infrared absorbing composition (IR-1 ) was made.
Squarylium dye [1]: 10.0 parts Dispersant [B-2] solution: 7.5 parts Binder resin [A-2] solution: 35.0 parts Propylene glycol monomethyl ether acetate: 47.5 parts

[Examples 74-86, Comparative Examples 13-14]
(Near-infrared absorbing composition (IR-2 to 16))
Near-infrared absorbing composition (IR-1) was prepared in the same manner as the near-infrared absorbing composition (IR-1), except that the squarylium dye, resin [A-2], dispersant [C], and organic solvent were changed to the compositions and amounts shown in Table 6. Absorbing compositions (IR-2 to 16) were prepared.

<Evaluation of near-infrared absorbing composition>
The obtained near-infrared absorbing compositions (IR-1 to 16) were tested for viscosity, storage stability, near-infrared absorbing ability, invisibility, heat resistance and light resistance by the following methods. Table 7 shows the results. In the following evaluation results, ⊚ to ∘ are practical levels, and Δ to × are non-practical levels.

(Viscosity evaluation)
The obtained near-infrared absorbing composition was measured for viscosity at 25° C. and a rotation speed of 50 rpm using an E-type viscometer ("ELD type viscometer" manufactured by Toki Sangyo Co., Ltd.). Evaluation was made according to the following criteria.
◎: less than 5 mPa s ○: 5 mPa s or more and less than 10 mPa s △: 10 mPa s or more and less than 30 mPa s ×: 30 mPa s or more

(Storage stability)
The obtained near-infrared absorbing composition was stored in a constant temperature machine at 60° C. for 1 week and accelerated over time, and then the viscosity was measured in the same manner as the viscosity evaluation to determine the viscosity change rate of the ink before and after aging. Evaluation was made according to the following criteria.
◎: Rate of change less than ±3% ○: Rate of change ±3% or more, less than ±5% △: Rate of change ±5% or more, less than ±15% ×: Rate of change ±15% or more

(Near-infrared absorption capacity)
The obtained near-infrared absorbing composition was spin-coated on a glass substrate having a thickness of 1.1 mm using a spin coater to a film thickness of 1.0 μm, dried at 60° C. for 5 minutes, and coated at 230° C. for 5 minutes. It was heated for 1 minute to prepare a substrate. The absorption spectrum of the resulting substrate was measured using a spectrophotometer (U-4100, manufactured by Hitachi High-Technologies Corporation) in the wavelength range of 300 to 1000 nm. The maximum absorption of the squarylium dye [A] of the present specification is in the region of 750 to 950 nm, and the absorbance at the maximum absorption wavelength was used to evaluate the near-infrared absorption ability according to the following criteria.
◎: absorbance at the maximum absorption wavelength is 1.5 or more ○: absorbance at the maximum absorption wavelength is 1.0 or more and less than 1.5 △: absorbance at the maximum absorption wavelength is 0.5 or more and less than 1.0 ×: maximum absorption Absorbance at wavelength less than 0.5

(invisibility)
Using the absorption spectrum in the wavelength range of 300 to 1000 nm obtained by the above method, the absorbance at the maximum absorption wavelength is normalized to 1, and the "average absorbance at 400 to 700 nm" is used to measure the invisibility according to the following criteria. evaluated with
◎: less than 0.03 ○: 0.03 or more and less than 0.05 △: 0.05 or more and less than 0.1 ×: 0.1 or more

(Heat resistance test)
A test substrate was prepared in the same procedure as the evaluation of near-infrared absorption ability, and as a heat resistance test, it was heated at 250 ° C. for 2
Heated for 0 minutes. The absorbance at the maximum absorption wavelength of the substrate was measured, the residual ratio to that before the heat resistance test was determined, and the heat resistance was evaluated according to the following criteria. The residual ratio was calculated using the following formula.
Residual rate = (absorbance after heat resistance test) / (absorbance before heat resistance test) x 100
◎: Residual rate is 95% or more ○: Residual rate is 90% or more and less than 95% △: Residual rate is 85% or more and less than 90% ×: Residual rate is less than 85%

(Light resistance test)
A test substrate was prepared in the same procedure as the evaluation of near-infrared absorption ability, and a light resistance tester (TOYOSEI
It was placed in "SUNTEST CPS+" manufactured by KI Co., Ltd. and left for 24 hours. At this time, the test was performed with an irradiance of 47 mW/cm ² and broadband light of 300 to 800 nm. The absorbance at the maximum absorption wavelength of the substrate was measured, the residual ratio to that before light irradiation was determined, and the light resistance was evaluated according to the following criteria. The residual ratio was calculated using the following formula.
Residual rate = (absorbance after irradiation) / (absorbance before irradiation) x 100
◎: Residual rate is 95% or more ○: Residual rate is 90% or more and less than 95% △: Residual rate is 85% or more and less than 90% ×: Residual rate is less than 85%

The near-infrared absorbing compositions (IR-1 to 14) of the present invention exhibited very good performance as compositions in terms of stability, optical properties and resistance. On the other hand, the compositions of the comparative examples have serious problems in the optical properties of IR-15 and in the resistance of IR-16, and have not reached a practical level. It is speculated that this is due to "strong color development", "high fastness", and "appropriate crystallinity" derived from the structure that the squarylium dye of the present invention remarkably possesses among perimidine-type squarylium dyes.

In addition, since it has excellent stability as a composition, it is not limited to solid coating like this time, but it can be used for pattern forming coating such as photolithography and dry etching, printing coating such as UV offset and gravure. , and can be adapted to various coating processes. Furthermore, it is not limited to the coating substrate. In addition, it has very good optical properties (near-infrared absorption ability, invisibility) and resistance (heat resistance, light resistance). Therefore, in addition to the above image forming materials, it can be suitably used for applications such as near-infrared cut filter materials, heat ray cut materials, light-to-heat conversion materials including laser welding, and solid-state imaging device materials.

<Production of composition for solid-state imaging device>
[Example 87]
(Production of solid-state imaging device composition (CM-1))
After stirring and mixing the following mixture so that it becomes uniform, 1. After filtration through a 0 μm filter, a solid-state imaging device composition (CM-1) was obtained.
Near-infrared absorption composition (IR-11): 30.0 parts binder resin [A-2] solution: 13.9 parts photopolymerizable compound (manufactured by Toagosei Co., Ltd. "Aronix M-350"): 3.2 parts light Polymerization initiator (manufactured by BASF "OXE-01"): 0.2 parts PGMAc: 52.7 parts

[Example 88]
(Production of solid-state imaging device composition (CM-2))
After stirring and mixing the following mixture so that it becomes uniform, 1. After filtration through a 0 μm filter, a solid-state imaging device composition (CM-2) was obtained.
Near-infrared absorbing composition (IR-11): 30.0 parts Binder resin [A-2] solution: 13.3 parts Hindered phenolic antioxidant (manufactured by BASF "IRGANOX 1010")
: 0.2 parts Photopolymerizable compound (manufactured by Toagosei Co., Ltd. "Aronix M-350"): 3.2 parts Photopolymerization initiator (manufactured by BASF "OXE-01"): 0.2 parts PGMAc: 53.1 Department

[Example 89]
(Production of solid-state imaging device composition (CM-3))
Photopolymerizable compound ("Aronix M-350" manufactured by Toagosei Co., Ltd.) and photopolymerization initiator ("OXE-01" manufactured by BASF) were changed to epoxy resin ("EX-611" manufactured by Nagase Chemtex Co., Ltd.). A composition for a solid-state imaging device (CM-3) was obtained in the same manner as the composition for a solid-state imaging device (CM-2) except that

[Comparative Examples 15 to 20]
(Production of compositions for solid-state imaging devices (CM-4 to 9))
Hereinafter, solid-state imaging device compositions (CM-4 to 9) were prepared in the same manner as the solid-state imaging device compositions (CM-1) to (CM-3), except that the compositions and blending amounts were changed to those shown in Table 8. got

<Evaluation of composition for solid-state imaging device>
The obtained compositions for solid-state imaging devices (CM-1 to 9) were tested for near-infrared absorption ability, invisibility, heat resistance, light resistance, pattern peelability (1 or 2), and pattern formability by the following methods. I went with Table 9 shows the results.

(Near-infrared absorption capacity)
The obtained composition for a solid-state imaging device was spin-coated on a glass substrate having a thickness of 1.1 mm using a spin coater so that the film thickness after drying was 1.0 μm, and dried at 60° C. for 5 minutes. , and heated at 230° C. for 5 minutes to fabricate a substrate. The absorption spectrum of the resulting substrate was measured using a spectrophotometer (U-4100, manufactured by Hitachi High-Technologies Corporation) in the wavelength range of 300 to 1000 nm. The maximum absorption of the squarylium dye of the present specification is in the region of 750 to 950 nm, and the absorbance at the maximum absorption wavelength was used to evaluate the near-infrared absorption ability according to the following criteria.
◎: absorbance at the maximum absorption wavelength is 1.0 or more ○: absorbance at the maximum absorption wavelength is 0.7 or more and less than 1.0 △: absorbance at the maximum absorption wavelength is 0.5 or more and less than 0.7 ×: maximum absorption Absorbance at wavelength less than 0.5

(invisibility)
Using the absorption spectrum in the wavelength range of 300 to 1000 nm obtained in the near-infrared absorption test, when the absorbance at the maximum absorption wavelength is normalized to 1, the "average absorbance of 400 to 700 nm" determines the invisibility. Evaluation was made according to the following criteria.
◎: less than 0.05 ○: 0.05 or more and less than 0.07 △: 0.07 or more and less than 0.1 ×: 0.1 or more

(Heat resistance test)
A substrate was prepared in the same manner as in the evaluation of near-infrared absorption ability. The substrate was heated at 250° C. for 20 minutes as a heat resistance test. Next, the absorbance at the maximum absorption wavelength of the substrate was measured, the residual ratio to the absorbance before the heat resistance test was determined, and the heat resistance was evaluated according to the following criteria. In addition, calculation of the survival rate was calculated using the following formula.
Residual rate = (absorbance after heat resistance test) / (absorbance before heat resistance test) x 100
◎: Residual rate is 95% or more ○: Residual rate is 90% or more and less than 95% △: Residual rate is 85% or more and less than 90% ×: Residual rate is less than 85%

(Light resistance test)
A substrate was prepared in the same manner as in the evaluation of near-infrared absorption ability. The substrate was placed in a light resistance tester ("SUNTEST CPS+" manufactured by TOYOSEIKI) and left for 24 hours under the conditions of an irradiance of 47 mW/cm ² and broadband light of 300 to 800 nm. The absorbance at the maximum absorption wavelength of the substrate was measured, the residual ratio to the absorbance before light irradiation was determined, and the light resistance was evaluated according to the following criteria. The residual ratio was calculated using the following formula.
Residual rate = (absorbance after irradiation) / (absorbance before irradiation) x 100
◎: Residual rate is 95% or more ○: Residual rate is 90% or more and less than 95% △: Residual rate is 85% or more and less than 90% ×: Residual rate is less than 85%

(Pattern peelability 1)
[Formation of infrared absorption pattern]
The composition for a solid-state imaging device (CM-1, 2, 4, 5, 7, 8) obtained by the above method was spin-coated onto an 8-inch silicon wafer so that the film thickness after drying was 1.0 μm. was applied to Then, the coating was dried by heat treatment with a hot plate at a surface temperature of 100° C. for 120 seconds.

Next, the film is passed through a mask pattern in which square pixels of 1.2 μm are arranged in dots in an area of 10 mm×10 mm on the substrate by an i-line stepper (FPA-3000i5+ manufactured by Canon Inc.). , and an exposure amount of 1000 mJ/cm ² .

After the pattern exposure, the film was puddle developed for 60 seconds at room temperature using an organic alkaline developer (PK-DEX4310 manufactured by Parker Corporation), and then rinsed with pure water using a spin shower for 20 seconds. did. After that, it was further washed with pure water. Thereafter, water droplets were blown off with high-pressure air, the substrate was naturally dried, and post-baked on a hot plate at 230° C. for 300 seconds to form a dot-shaped infrared absorption pattern.

For the obtained infrared absorption pattern, the number of occurrences of pattern peeling was inspected with a defect inspection apparatus "ComPLUS3" manufactured by Applied Materials Technology, Inc. to detect defective portions, and the number of defects due to peeling was extracted from these defective portions. . Evaluation was made according to the following evaluation criteria based on the number of peeling defects extracted. As for the inspection area, 200 areas each having a length of 10 mm and a width of 10 mm were prepared on an 8-inch wafer and evaluated.
・ : The number of peeling defects is 5 or less ◯ : The number of peeling defects is 6 or more and 10 or less △ : The number of peeling defects is 11 or more and 20 or less × : The number of peeling defects is 21 or more.

(Pattern peelability 2)
[Formation of infrared absorption pattern]
The compositions for solid-state imaging devices (CM-3, 6, 9) obtained by the above method were applied onto an 8-inch silicon wafer by spin coating, dried on a hot plate at 100° C. for 180 seconds, and dried. Further, heat treatment (post-baking) was performed for 480 seconds using a hot plate at 200° C. to form a layer.

Next, a positive photoresist "FHi622BC" (manufactured by Fuji Film Electronic Materials Co., Ltd.) was applied on the layer and prebaked to form a photoresist layer.

Subsequently, the photoresist layer is pattern-exposed at an exposure amount of 350 mJ/cm ² using an i-line stepper (manufactured by Canon Inc.), and heated for 1 minute at a temperature at which the temperature of the photoresist layer or the ambient temperature becomes 90°C. processed. After that, development processing was performed for 1 minute with a developer “FHD-5” (manufactured by Fuji Film Electronic Materials Co., Ltd.), and post-baking was performed at 110° C. for 1 minute to form a resist pattern. This resist pattern is a pattern in which 1.2 μm square resist films are arranged in a checkered pattern in consideration of an etching conversion difference (reduction of pattern width due to etching).

Next, using the resist pattern as an etching mask, dry etching was performed in the following procedure. With a dry etching device (U-621, manufactured by Hitachi High-Technologies Corporation), RF power: 800 W, antenna bias: 400 W, wafer bias: 200 W, chamber internal pressure: 4.0 Pa, substrate temperature: 50 ° C., mixed gas A first-stage etching process was performed for 80 seconds with gas species and flow rates of CF ₄ : 80 mL/min, O ₂ : 40 mL/min, and Ar: 800 mL/min.

Under these etching conditions, the amount of etching of the layer was 356 nm (89% etching amount), leaving a residual film of about 44 nm.

Next, in the same etching chamber, RF power: 600 W, antenna bias: 100 W, wafer bias: 250 W, chamber internal pressure: 2.0 Pa, substrate temperature: 50° C., gas type and flow rate of the mixed gas were changed to N ₂ : 500 mL/min, O ₂ : 50 mL/min, Ar: 500 mL/min (N ₂ /O ₂ /Ar = 10/1/10), the over-etching rate in the total etching is 20%, and the second stage etching process , an over-etching process was performed.

The etching rate of the infrared absorption pattern layer under the etching conditions of the second stage was 600 nm/min or more, and it took about 10 seconds to etch the remaining film of the layer. The etching time was calculated by adding the etching time of 80 seconds in the first stage and the etching time of 10 seconds in the second stage. As a result, the etching time was set to 80+10=90 seconds, the over-etching time was set to 90×0.2=18 seconds, and the total etching time was set to 90+18=108 seconds.

After performing dry etching under the above conditions, stripping treatment is performed for 120 seconds using a photoresist stripper "MS230C" (manufactured by Fujifilm Electronic Materials Co., Ltd.) to remove the resist pattern, and further cleaning with pure water. , spin drying was performed. After that, dehydration baking treatment was performed at 100° C. for 2 minutes.

Regarding the infrared absorption pattern prepared above, the number of occurrences of pattern peeling was evaluated in the same manner as in (Pattern peeling property 1).

(pattern formability)
The infrared absorption pattern prepared in the above pattern peeling evaluation was cut out with a glass cutter and observed at a magnification of 15,000 using a scanning electron microscope (S-4800, manufactured by Hitachi, Ltd.). was evaluated according to
○: A pattern with a line width of 1.2 μm is formed with good linearity. △: A slight rattle is confirmed in the pattern with a line width of 1.2 μm, but there is no practical problem. ×: A pattern with a line width of 1.2 μm. linearity is remarkably poor.

The compositions for solid-state imaging devices (CM-1 to 3) of the present specification have excellent near-infrared absorption ability, invisibility, heat resistance, and light resistance, as well as good pattern peelability and pattern formability. It can be suitably used for imaging device applications. It also exhibits high performance in both photolithography and dry etching, which are typical pattern forming processes.

From the above results, it was found that the squarylium dye of the present specification can be used in a wide range of applications. As described above, the reason for this is presumed to be that, among the perimidine-type squarylium dyes, the structure of the squarylium dye of the present specification has strong color development, strong fastness, and moderate crystallinity. , and extremely excellent optical properties, high various resistances, and stability as a composition for each application form.

Claims (5)

Represented by the following general formula (1), in the X-ray diffraction pattern with CuKα rays, at least Bragg angles 2θ (±0.2°) of 8.5°, 12.7°, 15.3°, and 16.0 A squarylium dye having diffraction peaks at 17.5°, 19.6°, 22.4° and 26.6° .
General formula (1)

[In general formula (1),
R ₁ to R ₅ each independently represent a hydrogen atom, a sulfo group or a halogen atom.
X ₁ to X ₄ each independently represent a hydrogen atom, an optionally substituted alkyl group, an amino group, a hydroxyl group, a cyano group, a sulfo group, a nitro group, or a halogen atom. ] A composition comprising the squarylium dye according to claim 1 and a resin [A]. A composition for a solid-state imaging device, comprising the squarylium dye according to claim 1, a resin [A], and a dispersant [B]. A near-infrared cut filter comprising a substrate and a layer formed from the composition for a solid-state imaging device according to claim 3 . A solid-state imaging device comprising the near-infrared cut filter according to claim 4 .

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