Black film compound, black film, and method of manufacturing black film

Abstract

To provide a black film composition which suppresses polymer granulation and enables production of a black film with superior adhesion and temporal stability, and to provide a black film formed using the same, and a method of manufacturing the black film.SOLUTION: A black film composition is provided, comprising a solvent, a compound having an aromatic ring with a hydroxy group, and an amine compound.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a composition for a black film, a black film, and a method for producing a black film. [Background technology]

[0002] Carbon black has traditionally been the most commonly used black material, with other materials such as iron oxide black (iron tetroxide) also being used. These materials are black and absorb light with wavelengths ranging from the visible light region to the far-infrared region, so articles such as coatings colored with these black materials are prone to becoming hot due to the absorption of sunlight. In addition, because carbon black is electrically conductive, articles colored with carbon black have the property of having poor electrical insulation. On the other hand, in recent years, with the use of infrared laser radiation and the development of corresponding sensors in the fields of electronic devices and optical devices, there are an increasing number of fields that require black materials with properties that are not found in black materials such as carbon black that have been commonly used in the past. For example, in infrared communications, infrared camouflage, optical filters, etc., oil-soluble dyes have been used as coloring materials for infrared-transmitting filters, but these oil-soluble dyes have problems with durability such as heat resistance, solvent resistance, and light resistance, and therefore dark-colored materials that have excellent durability and excellent infrared transmittance are required. Also, from the viewpoint of energy conservation, heat-shielding coatings that reflect sunlight are desired, and heat-reflecting materials for this purpose are required for use in coatings for roofs and walls of structures, road paving, the exterior and interior of automobiles, and for heat-rising materials such as paints for electronic components, as well as for agricultural use as heat-shielding materials.

[0003] In particular, black materials having sufficient transmittance to light rays having wavelengths from near infrared to infrared have been put to practical use. For example, Patent Document 1 describes a dark azo pigment obtained by a coupling reaction between 2-hydroxy-11H-benzo[a]carbazole-3-carboxy-N-benzimidazolone-5-amide as a coupling component and a known diazo compound as a diazo component. Patent Document 2 also describes a black film having a volume fraction of 2% by volume or more and 30% by volume or less, an average dispersed particle diameter in the film of 1 nm or more and 200 nm or less, an optical density per 1 μm of thickness of 1 or more, and a volume resistivity of 10 11 Black films with a resistivity of Ω·cm or more have been described. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2010 / 044393 [Patent Document 2] International Publication No. 2012 / 026577 Summary of the Invention [Problem to be solved by the invention]

[0005] However, the black films obtained in Patent Documents 1 and 2 are formed from black particles, making it difficult to uniformly arrange the particles. This results in uneven color, making it difficult to stabilize the amount of light transmitted and the transmitted wavelength over a wide area. Furthermore, the inclusion of black particles leads to the problem of insufficient adhesion to the substrate. Furthermore, there is a problem of poor stability over time, such as the black particles detaching from the coating film, resulting in insufficient light-blocking properties.

[0006] In view of the above-described current situation, an object of the present invention is to provide a composition for a black film that can suppress polymer particulation and produce a black film that is excellent in adhesion and stability over time. Another object of the present invention is to provide a black film formed using the composition for a black film and a method for producing the black film. [Means for solving the problem]

[0007] The present disclosure (1) is a composition for a black film, which comprises a solvent, a compound having an aromatic ring containing a hydroxy group, and an amine compound. Disclosure (2) is the composition for black films of Disclosure (1), wherein the compound having an aromatic ring containing a hydroxy group is a compound having a naphthalene ring containing two or more hydroxy groups, and the compound having a naphthalene ring has hydroxy groups at the 1st and 2nd positions, the 1st and 3rd positions, the 1st and 5th positions, the 1st and 6th positions, the 1st and 7th positions, the 2nd and 3rd positions, the 2nd and 6th positions, or the 2nd and 7th positions. The present disclosure (3) is the composition for black films according to the present disclosure (1) or (2), further comprising polymethyl methacrylate. The present disclosure (4) is a black film formed using the black film composition of the present disclosure (1), (2), or (3). The present disclosure (5) is a method for producing a black film, comprising step 1 of preparing a composition for a black film by adding a compound having an aromatic ring containing a hydroxyl group and an amine compound to a solvent and stirring the mixture; step 2 of curing the composition for a black film at a constant temperature; step 3 of maintaining the composition for a black film in a film form; and step 4 of curing the composition for a black film maintained in a film form. The present disclosure (6) is the method for producing a black film according to the present disclosure (5), wherein the compound having an aromatic ring containing a hydroxy group is a compound having a naphthalene ring containing two or more hydroxy groups, and the compound having a naphthalene ring has hydroxy groups at the 1st and 2nd positions, the 1st and 3rd positions, the 1st and 5th positions, the 1st and 6th positions, the 1st and 7th positions, the 2nd and 3rd positions, the 2nd and 6th positions, or the 2nd and 7th positions. The present disclosure (7) is the method for producing a black film according to the present disclosure (5) or (6), further comprising adding polymethyl methacrylate in step 1. The present invention will be described in detail below.

[0008] As a result of extensive research, the present inventors have found that by preparing a composition containing a compound having an aromatic ring containing a hydroxyl group, an amine compound, and a solvent, it is possible to form a film while suppressing particulate formation of the reaction product, and to obtain a black film with excellent stability over time with minimal particle detachment from the film.Furthermore, they have found that such a film has excellent adhesion to a substrate, which has led to the completion of the present invention.

[0009] The composition for a black film contains a solvent, a compound having an aromatic ring containing a hydroxy group, and an amine compound. The solvent may be a protic solvent or an aprotic solvent.

[0010] Examples of the aprotic solvent include amide solvents such as N,N-dimethylformamide, N,N-dimethylacetamide, N-methyl-2-pyrrolidone, N-methylcaprolactam, 1,3-dimethylimidazolidinone, and tetramethylurea; lactone solvents such as γ-butyrolactone and γ-valerolactone; phosphorus-containing amide solvents such as hexamethylphosphoric amide and hexamethylphomphinetriamide; sulfur-containing solvents such as dimethyl sulfone, dimethyl sulfoxide, and sulfolane; ketone solvents such as acetone, cyclohexanone, and methylcyclohexanone; amine solvents such as picoline and pyridine; ester solvents such as 2-methoxy-1-methylethyl acetate; and ether solvents such as diethyl ether and tetrahydrofuran. Among these, amide solvents and ether solvents are preferred, and N,N-dimethylformamide and tetrahydrofuran are more preferred.

[0011] Examples of the protic solvent include alcohol solvents such as methanol, ethanol, propanol, isopropanol, and butanol.

[0012] The composition for a black film contains a compound having an aromatic ring containing a hydroxy group. By reacting the above compound with an amine compound, a copolymer having low transmittance in the visible light region can be obtained. Examples of the aromatic ring include a benzene ring, a naphthalene ring, an anthracene ring, a pyrene ring, a phenanthrene ring, a triphenylene ring, etc. Of these, a benzene ring and a naphthalene ring are preferred.

[0013] The compound having a naphthalene ring containing a hydroxy group may be a compound having a naphthalene ring containing one hydroxy group, or may be a compound having a naphthalene ring containing two or more hydroxy groups. Among these, a compound having a naphthalene ring containing two or more hydroxy groups is preferred, and a compound having a naphthalene ring containing two hydroxy groups is more preferred. Furthermore, the compound having a naphthalene ring containing two or more hydroxy groups is preferably one having hydroxy groups at the 1st and 2nd positions, 1st and 3rd positions, 1st and 5th positions, 1st and 6th positions, 1st and 7th positions, 2nd and 3rd positions, 2nd and 6th positions, or 2nd and 7th positions, more preferably one having hydroxy groups at the 1st and 3rd positions, 1st and 5th positions, or 1st and 6th positions, and even more preferably one having hydroxy groups at the 1st and 5th positions. Examples of the compound having a naphthalene ring containing a hydroxy group include 1-naphthol, 2-naphthol, dihydroxynaphthalene, trihydroxynaphthalene, tetrahydroxynaphthalene, pentahydroxynaphthalene, etc. Among these, dihydroxynaphthalene and 1-naphthol are preferred, and as dihydroxynaphthalene, 1,2-dihydroxynaphthalene, 1,3-dihydroxynaphthalene, 1,5-dihydroxynaphthalene, 1,6-dihydroxynaphthalene, 1,7-dihydroxynaphthalene, 2,3-dihydroxynaphthalene, 2,6-dihydroxynaphthalene, and 2,7-dihydroxynaphthalene are preferred, 1,3-dihydroxynaphthalene, 1,5-dihydroxynaphthalene, and 1,6-dihydroxynaphthalene are more preferred, and 1,5-dihydroxynaphthalene is even more preferred.

[0014] Furthermore, examples of compounds having a benzene ring containing a hydroxy group include phenol and its derivatives, catechol, resorcinol, hydroquinone and its derivatives, hydroxyquinol, phloroglucinol, pyrogallol and its derivatives, and tetrahydroxybenzene and its derivatives.

[0015] Other compounds that can be used include 1-hydroxypyrene, 9-phenanthrol, and 2,3,6,7,10,11-hexahydroxytriphenylene, as the compounds having an aromatic ring containing a hydroxy group.

[0016] It is preferable to use a combination of multiple types of compounds having aromatic rings containing hydroxyl groups.In this case, it is preferable to use a combination of compounds having aromatic rings containing different hydroxyl groups, and it is more preferable to use a combination of a compound having a naphthalene ring containing hydroxyl groups and a compound having a benzene ring containing hydroxyl groups.This makes it possible to exhibit the properties of visible light blocking by the naphthalene ring and near-infrared light transmission by the benzene ring, which are difficult to coexist.Furthermore, it is also possible to use a combination of multiple types of compounds having a naphthalene ring containing hydroxyl groups. A hydroxy group bonded to an aromatic ring expresses the nucleophilicity of the aromatic ring (becoming the starting point for nucleophilic attack on the aromatic ring), so it is preferable for the compound to have a hydrogen atom at the ortho- and / or para-position of the hydroxy group (in the case of a compound having a naphthalene ring containing a hydroxy group, at the ortho- and / or para-position of the hydroxy group on the benzene ring on which the hydroxy group is substituted). This allows for thorough attack. Specifically, in the case where the naphthalene ring containing a hydroxy group has one hydroxy group, when the hydroxy group is substituted at the 1-position, it is preferable that there be only unsubstituted hydrogen atoms at the 2- and / or 4-positions, and when the hydroxy group is substituted at the 2-position, it is preferable that there be only unsubstituted hydrogen atoms at the 1- and / or 3-positions. In the case where there are two hydroxy groups, when one hydroxy group is substituted at the 1-position, it is preferable that there be only unsubstituted hydrogen atoms at the 2- and 4-positions, and the second hydroxy group is substituted at the 5-, 6-, 7-, and 8-positions, and when one hydroxy group is substituted at the 2-position, it is preferable that there be only unsubstituted hydrogen atoms at the 1- and 3-positions, and the second hydroxy group is substituted at the 5-, 6-, 7-, and 8-positions.

[0017] Furthermore, the compound having a benzene ring containing a hydroxy group preferably has 1 to 3 hydroxy groups, and the compound having a naphthalene ring containing a hydroxy group preferably has 1 to 4 hydroxy groups, more preferably 2 to 3, and even more preferably 2. This makes it possible to maintain general nucleophilic attacking properties.

[0018] The composition for black films contains an amine compound. The amine compound functions as an auxochrome that donates electrons to a compound having an aromatic ring containing a hydroxyl group as a chromophore, and therefore, the visible light transmittance of the resulting black film can be sufficiently reduced. Examples of the amine compound include compounds containing an amino group, cyclic amine compounds, and heterocyclic compounds containing a nitrogen atom. The amino group-containing compound may have an ether group, a hydroxy group, or the like in addition to the amino group. Furthermore, the above-mentioned compound containing an amino group is not particularly limited as long as it contains an amino group, and examples thereof include those containing a primary amino group, a secondary amino group, and a tertiary amino group, but those containing a primary amino group are preferred.

[0019] As the compound containing an amino group, in addition to ammonia and hydrazine, chain aliphatic amines, alicyclic amines, aromatic amines, alkanolamines, etc. can be used. Of these, aromatic amines are preferred.

[0020] Examples of the aromatic amine include aromatic monoamines and aromatic polyamines. Examples of the aromatic monoamine include aniline, p-toluidine, p-ethylaniline, p-anisidine, α-naphthylamine, p-butylaniline, p-phenetidine, 4-aminophenol, etc. Of these, aniline and p-anisidine are preferred. Examples of the aromatic polyamine include N,N-dimethyl-1,4-phenylenediamine, tolylenediamine, and 4,4'-diaminodiphenylmethane. In particular, in the aromatic polyamine, the first amino group is preferably a primary amino group without a substituent, and preferably has an electron-donating alkyl group, amino group, or alkoxy group at the ortho- or para-position of the amino group, more preferably at the para-position. The second or subsequent amino group or alkoxy group substituted at the para-position is preferably substituted with an alkyl group and free of active hydrogen.

[0021] Examples of the chain aliphatic amine include ethylamine, 1-propylamine, 2-propylamine, 1-butylamine, 1-pentylamine, 1-hexylamine, 1-heptylamine, 1-octylamine, 1-laurylamine, 1,2-ethanediamine, 1,3-propanediamine, 1,4-butanediamine, 1,5-pentanediamine, 1,6-hexanediamine, ethylenetriamine, diethylenetriamine, ethylhydrazine, 1-propylhydrazine, 1-butylhydrazine, 1-pentylhydrazine, 1-hexylhydrazine, 1-heptylhydrazine, 1-octylhydrazine, succinic acid dihydrazide, terephthalic acid dihydrazide, guanidine, 1-butylguanidine, 1-cyanoguanidine, and dicyandiamide.

[0022] Examples of the alicyclic amine include cyclopropylamine, cyclobutylamine, cyclopentylamine, cyclohexylamine, cyclopropanediamine, isophoronediamine, cyclobutanediamine, cyclopentanediamine, cyclohexanediamine, bis(4-aminocyclohexyl)methane, piperazine, and N-aminoethylpiperazine. Examples of the alkanolamine include monoethanolamine, diethanolamine, and triethanolamine.

[0023] Examples of the cyclic amine compound include cyclic monoamines and cyclic polyamines. Examples of the cyclic monoamine include secondary cyclic monoamines, tertiary cyclic monoamines, and quaternary cyclic monoamines. Examples of secondary cyclic monoamines include piperidines, which are secondary cyclic amines such as piperidine, 2-pipecoline, 3-pipecoline, 4-pipecoline, 2,6-dimethylpiperidine, and 3,5-dimethylpiperidine; pyrrolidines such as pyrrolidine, 2-methylpyrrolidine, and 3-methylpyrrolidine; and morpholines such as morpholine, 2-methylmorpholine, and 3-methylmorpholine. Examples of tertiary cyclic monoamines include piperidines such as N-methylpiperidine, pyrrolidines such as N-methylpyrrolidine, and morpholines such as N-methylmorpholine. Examples of the quaternary cyclic monoamines include fluorides, chlorides, bromides, iodides, sulfates, hydrogen sulfates, acetates, etc. of piperidines, pyrrolidines, morpholines, etc.

[0024] Examples of cyclic polyamines include aliphatic cyclic polyamines such as 1,3,5-trimethyl-1,3,5-triazinane (hexahydro-1,3,5-trimethyl-1,3,5-triazine), hexamethylenetetramine, and cyclene.

[0025] Examples of the heterocyclic compound containing a nitrogen atom include pyridine, 1,2,3-triazine, 1,2,4-triazine, 1,3,5-triazine, and melamine.

[0026] The amine compound is preferably a cyclic amine compound, more preferably an aliphatic cyclic polyamine, and even more preferably 1,3,5-trimethyl-1,3,5-triazinane.

[0027] The mass ratio of the amine compound to the compound having an aromatic ring containing a hydroxyl group in the composition for black films (amine compound / compound having an aromatic ring containing a hydroxyl group) is preferably 0.1 or more and 50 or less, more preferably 0.5 or more and 30 or less, and even more preferably 0.8 or more and 10 or less. When the mass ratio is 0.1 or more, the visible light blocking property can be improved, and when the mass ratio is 50 or less, the infrared transmittance can be improved. The compound having an aromatic ring containing a hydroxy group is preferably a combination of a compound having a naphthalene ring containing a hydroxy group and a compound having a benzene ring containing a hydroxy group. In this case, the mass ratio of the compound having a benzene ring containing a hydroxy group to the compound having a naphthalene ring containing a hydroxy group (compound having a benzene ring containing a hydroxy group / compound having a naphthalene ring containing a hydroxy group) is preferably 0.1 or more and 50 or less, more preferably 0.5 or more and 30 or less, and even more preferably 1 or more and 10 or less.

[0028] The molar ratio of the amine compound to the compound having an aromatic ring containing a hydroxyl group in the composition for black films (amine compound / compound having an aromatic ring containing a hydroxyl group) is preferably 0.5 or more and 50 or less, and more preferably 0.8 or more and 10 or less. When the ratio is 0.5 or more, the visible light blocking property can be improved, and when the ratio is 50 or less, the infrared transmittance can be improved. In addition, the molar ratio of the compound having a benzene ring containing a hydroxy group to the compound having a naphthalene ring containing a hydroxy group in the composition for black films (compound having a benzene ring containing a hydroxy group / compound having a naphthalene ring containing a hydroxy group) is preferably 0.5 or more and 50 or less, and more preferably 1 or more and 10 or less.

[0029] The black film composition may contain a thermoplastic resin, which can impart elasticity to the resulting black film and suppress the occurrence of cracks or fractures in the film. Examples of the thermoplastic resin include polyethylene, polypropylene, polystyrene, polyvinyl chloride, polyacrylamide resins, poly(meth)acrylic resins, and ethylene-vinyl acetate copolymers. Of these, poly(meth)acrylic resins are preferred, and polymethyl methacrylate is more preferred.

[0030] The black film composition may contain a crosslinking agent. By including the crosslinking agent, the copolymer obtained by reacting the compound having an aromatic ring containing a hydroxyl group with the amine compound is crosslinked, and the constituent elements are resinified to form a black film with excellent handleability. In this case, the copolymer has a structure having a constitutional unit derived from the compound having an aromatic ring containing a hydroxyl group, a constitutional unit derived from the amine compound, and a constitutional unit derived from the crosslinking agent. The crosslinking agent is different from the compound having an aromatic ring containing a hydroxy group and the amine compound.

[0031] The crosslinking agent is preferably an electrophilic reactant that is susceptible to phenolic nucleophilic attack. Examples of the crosslinking agent include polyamine-based crosslinking agents, thiourea-based crosslinking agents, thiadiazole-based crosslinking agents, triazine-based crosslinking agents, quinoxaline-based crosslinking agents, bisphenol-based crosslinking agents, organic peroxide-based crosslinking agents, aldehyde-based crosslinking agents, silane-based crosslinking agents, etc. Phenol-based crosslinking agents such as resol phenolic resins can also be used.

[0032] Examples of the polyamine crosslinking agent include ethylenediamine, hexamethylenediamine, diethylenetriamine, triethylenetetramine, hexamethylenetetramine, p-phenylenediamine, cumenediamine, N,N'-dicinnamylidene-1,6-hexanediamine, ethylenediamine carbamate, and hexamethylenediamine carbamate. Examples of the thiourea-based crosslinking agent include 2-mercaptoimidazoline (ethylene thiourea), 1,3-diethyl thiourea, 1,3-dibutyl thiourea, and trimethyl thiourea. Examples of the thiadiazole crosslinking agent include 2,5-dimercapto-1,3,4-thiadiazole, and 2-mercapto-1,3,4-thiadiazole-5-thiobenzoate. Examples of the triazine crosslinking agent include 2,4,6-trimercapto-1,3,5-triazine, 2-hexylamino-4,6-dimercaptotriazine, 2-diethylamino-4,6-dimercaptotriazine, 2-cyclohexylamino-4,6-dimercaptotriazine, 2-dibutylamino-4,6-dimercaptotriazine, 2-anilino-4,6-dimercaptotriazine, and 2-phenylamino-4,6-dimercaptotriazine. Examples of the quinoxaline-based crosslinking agent include 2,3-dimercaptoquinoxaline, quinoxaline-2,3-dithiocarbonate, 6-methylquinoxaline-2,3-dithiocarbonate, and 5,8-dimethylquinoxaline-2,3-dithiocarbonate. Examples of the bisphenol-based crosslinking agent include bisphenol AF and bisphenol S. Examples of the organic peroxide crosslinking agent include tert-butyl hydroperoxide, p-menthane hydroperoxide, dicumyl peroxide, tert-butyl peroxide, 1,3-bis(tert-butylperoxyisopropyl)benzene, 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane, benzoyl peroxide, and tert-butyl peroxybenzoate. Examples of the aldehyde crosslinking agent include glyoxal, malondialdehyde, succindialdehyde, maleic dialdehyde, glutaric dialdehyde, formaldehyde, acetaldehyde, benzaldehyde, 1,4-dioxane, and 1,3,5-trioxane. Examples of the silane-based crosslinking agent include alkoxysilanes such as methyltrimethoxysilane, dimethyldimethoxysilane, vinyltrimethoxysilane, phenyltrimethoxysilane, and methyltriethoxysilane. Of these, polyamine-based crosslinking agents and aldehyde-based crosslinking agents are preferred because of their ease of addition (solvent solubility) and high reactivity (the carbon atom adjacent to the electron-withdrawing atom is located in a relatively large space (less steric hindrance)).

[0033] The mass ratio of the crosslinking agent to the compound having an aromatic ring containing a hydroxyl group in the composition for black film (crosslinking agent / compound having an aromatic ring containing a hydroxyl group) is preferably 0.3 or more and 10 or less, more preferably 0.5 or more and 5 or less, and even more preferably 0.5 or more and 2 or less.

[0034] The molar ratio of the crosslinking agent to the compound having an aromatic ring containing a hydroxyl group in the composition for black film (crosslinking agent / compound having an aromatic ring containing a hydroxyl group) is preferably 0.5 or more and 10 or less, and more preferably 0.5 or more and 2 or less.

[0035] The black film composition may further contain an additive. Examples of the additives include halogen compounds such as iodine, bromine, and chlorine; protonic acids such as sulfuric acid, hydrochloric acid, nitric acid, perchloric acid, fluoroboric acid, and phosphinic acid; various salts of these protonic acids; Lewis acids such as aluminum trichloride, iron trichloride, molybdenum chloride, antimony chloride, arsenic pentafluoride, and antimony pentafluoride; organic carboxylic acids such as acetic acid, trifluoroacetic acid, polyethylenecarboxylic acid, formic acid, benzoic acid, and citric acid; various salts of these organic carboxylic acids; phenols such as phenol, nitrophenol, and cyanophenol; various salts of these phenols; di-2-ethylhexyl sulfosuccinic acid, sulfosuccinic acid, and the like. salts of sulfosuccinic acids; polymeric acids such as polyacrylic acid; alkyl phosphates such as propyl phosphate, butyl phosphate, and hexyl phosphate; polyalkylene oxide phosphates such as polyethylene oxide dodecyl ether phosphate and polyethylene oxide alkyl ether phosphate; various salts of alkyl phosphates and polyalkylene oxide phosphates; sulfates such as lauryl sulfate, cetyl sulfate, stearyl sulfate, and lauryl ether sulfate; and various salts of these sulfates.

[0036] The black film composition can be prepared, for example, by adding predetermined amounts of the compound having an aromatic ring containing a hydroxyl group and the amine compound to the solvent and stirring the mixture.

[0037] A black film can be formed by using the black film composition. Specifically, the black film composition is cured at a constant temperature, and then the black film composition is maintained in a film form by coating it on a substrate, and the film-like black film composition is further cured, thereby producing a black film with an excellent adhesion layer and stability over time. The present invention also includes a black film formed using the above black film composition.

[0038] The present invention also provides a method for producing a black film, which includes step 1 of adding a compound having an aromatic ring containing a hydroxyl group and an amine compound to a solvent and stirring the mixture to prepare a composition for a black film, step 2 of curing the composition for a black film at a constant temperature, step 3 of maintaining the composition for a black film in a film form, and step 4 of curing the composition for a black film maintained in a film form.

[0039] In the method for producing the black film, the composition for the black film in step 1 may have the same structure as the composition for the black film described above. The resulting black film may have the same structure as the black film described above.

[0040] In the above step 1, the stirring method may be a method using a general-purpose stirring device, such as a Nanomizer, an ultrasonic irradiation device, a ball mill, a sand mill, a basket mill, a three-roll mill, a planetary mixer, a bead mill, or a homogenizer.

[0041] In the method for producing the black film, step 2 is carried out in which the composition for the black film obtained in step 1 is cured at a constant temperature. In this specification, "curing" means leaving the material to stand in a constant temperature and humidity chamber or the like.

[0042] In the above step 2, the temperature during curing is preferably 30°C or higher, more preferably 45°C or higher, and is preferably 60°C or lower, more preferably 55°C or lower. By setting the content within the above range, the reaction between the compound having an aromatic ring containing a hydroxyl group and the amine compound in the black film composition proceeds gradually during aging, forming a composition with reduced visible light transmittance, and sufficient coatability can be achieved in Step 3 described below.

[0043] In the above step 2, the curing time is preferably 72 hours or more, more preferably 120 hours or more, and is preferably 216 hours or less, more preferably 168 hours or less. By setting the content within the above range, the reaction between the compound having an aromatic ring containing a hydroxyl group and the amine compound can be sufficiently promoted in the composition for black films during curing, thereby forming a composition with reduced visible light transmittance.Furthermore, sufficient coatability can be exhibited in Step 3 described below.

[0044] In the method for producing the black film, a step 3 is carried out in which the black film composition cured in the step 2 is maintained in a film form. In the above step 3, an example of a method for maintaining the black film composition in a film form is to coat the black film composition on a substrate. Examples of the coating method include methods using a roll coater, a die coater, a squeeze coater, a curtain coater, and drop casting.

[0045] The substrate may be a glass substrate, a resin substrate, etc. Examples of the resin substrate include those formed from fluorine-containing resins such as polyethylene terephthalate, polyester, polyethylene, polypropylene, polystyrene, polyimide, polyvinyl alcohol, polyvinyl chloride, and polyfluoroethylene, as well as nylon and cellulose.

[0046] In the method for producing the black film, a step 4 is carried out in which the black film composition maintained in a film form in the step 3 is cured. By carrying out the above step 4, the solvent contained in the black film composition can be sufficiently removed, and a black film having a sufficiently reduced visible light transmittance and excellent adhesion and stability over time can be produced. Furthermore, the reaction between the compound having an aromatic ring containing a hydroxyl group and the amine compound proceeds even during curing, further reducing the visible light transmittance and providing a black film having excellent stability over time.

[0047] In the above step 4, the temperature during curing is preferably 40°C or higher, more preferably 50°C or higher, and is preferably 70°C or lower, more preferably 60°C or lower. In addition, in the above step 4, the humidity during curing is preferably 10% or more, more preferably 20% or more, and is preferably 90% or less, more preferably 80% or less. By setting the temperature within the above range, the solvent can be sufficiently removed while the reaction between the compound having an aromatic ring containing a hydroxy group and the amine compound proceeds.

[0048] In the above step 4, the curing time is preferably 0.5 hours or more, more preferably 1 hour or more, and is preferably 3 hours or less, more preferably 2 hours or less. By setting the temperature within the above range, the solvent can be sufficiently removed while the reaction between the compound having an aromatic ring containing a hydroxy group and the amine compound proceeds.

[0049] The black film can be used in various applications requiring light-blocking properties, such as electronic device parts for mobile phones and personal computers, architectural parts for doors and glass, infrared filters, infrared laser filters, infrared detection security systems, infrared cameras, infrared sensors, fingerprint authentication, and ToF sensors. [Effects of the Invention]

[0050] According to the present invention, a composition for a black film can be provided that can suppress particulation of a polymer and produce a black film that is excellent in adhesion and stability over time. The present invention also provides a black film formed using the composition for a black film and a method for producing a black film. DETAILED DESCRIPTION OF THE INVENTION

[0051] The following examples will further illustrate the present invention, but the present invention is not limited to these examples.

[0052] Example 1 A 4 mL solution of 1,5-dihydroxynaphthalene (1,5-DHN, manufactured by Tokyo Chemical Industry Co., Ltd.) in tetrahydrofuran (THF) (243.5 mM DHN solution, 156 mg (0.97 mmol) of DHN) was prepared. A 4 mL solution of 1,3,5-trimethyl-1,3,5-triazinane (TMTA, manufactured by Tokyo Chemical Industry Co., Ltd.) in tetrahydrofuran (238.0 mM TMTA solution, 123 mg (0.95 mmol) of TMTA) was also prepared. A black film composition (DHN-TMTA solution) was prepared by mixing 3 mL of DHN solution (117.0 mg (0.73 mmol) of DHN) with 3 mL of TMTA solution (92.3 mg (0.71 mmol) of TMTA). The resulting DHN-TMTA solution was then left undisturbed in a thermo-humidistat chamber at 50°C and 20% RH for 9 days. Then, 0.4 mL of the solution that had been left standing for 9 days was drop-cast onto a 2 cm x 2 cm glass slide that had been hydrophilized by immersing it in an alkaline aqueous solution of pH 10-12 for at least one day, and heated in air at 50°C for 1 hour to remove the solvent, yielding a black film.

[0053] Example 2 A composition for a black film and a black film were prepared in the same manner as in Example 1, except that N,N-dimethylformamide (DMF) was used instead of THF.

[0054] Example 3 A PMMA solution was prepared by weighing out 100 mg of polymethyl methacrylate (PMMA, Fujifilm Wako Pure Chemical Industries, Ltd.), adding 1 mL of THF, and allowing the mixture to stand at room temperature for dissolution. 0.035 mL of the resulting PMMA solution was added to 0.4 mL of the solution obtained in Example 1 after standing for 9 days, and the mixture was mixed with external ultrasonic waves for 3 minutes. A black film was then obtained in the same manner as in Example 1.

[0055] Examples 4 to 12 A composition for a black film and a black film were prepared in the same manner as in Example 1, except that the compounds having an aromatic ring containing a hydroxy group and the solvents shown in Table 1 were used.

[0056] (evaluation) The black films obtained in the examples were evaluated as follows, and the results are shown in Table 1.

[0057] (1) Total light transmittance The light transmittance of the obtained black film in the wavelength range of 200 to 2600 nm was measured using a spectrophotometer with an integrating sphere (U-4100 model, manufactured by Hitachi, Ltd.) During the measurement, a reflector was attached to the side opposite to the light incident side, and the total light transmittance was measured. The measurement conditions were set as follows: [Measurement Mode: Wavelength Scan, Data Mode: %T, Start Wavelength: 2600.00 nm, End Wavelength: 200.00 nm, Scan Speed: 600 nm / min, Sampling Interval: 5.00 nm, Initial Wait Time: 0 s, Repeat Period: 0.0 min, Number of Measurements: 1, Auto-Zero Before Measurement: OFF, Slit: 8.00 nm, Photomultiplier Voltage: Auto 1, Light Source Switching Mode: Automatic Switching, Light Source Switching Wavelength: 340.00 nm, Baseline Setting: User 1, High Resolution Measurement: OFF, D2 Lamp: On, W1 Lamp: On, R / S Inversion: OFF, Light Attenuation Rate: Light Attenuation Plate Not Used], [Near Infrared; Scan Speed: 750 nm, Slit: Automatic Control, PbS Sensitivity: 2, Detector Switching Compensation: No Compensation, Detector Switching Wavelength: 850.0 nm, Light Intensity Control Mode: Fixed], [Peak Detection; Detection Method: Rectangular, Sensitivity: 1, Threshold: 0.01]

[0058] Next, the wavelength (T5) at which the transmittance first exceeded 5% and the wavelength (T80) at which the transmittance first exceeded 80% were determined using the transmittance measurements taken at 1 nm intervals. Furthermore, the average transmittance in the wavelength range of 370 nm or more and less than T5 and the average transmittance in the wavelength range of T80 or more and less than 2000 nm were calculated to determine the average transmittance.

[0059] [Table 1] [Industrial Applicability]

[0060] According to the present invention, a composition for a black film can be provided that can suppress particulation of a polymer and produce a black film that is excellent in adhesion and stability over time. The present invention also provides a black film formed using the composition for a black film and a method for producing a black film.

Claims

1. A composition for a black film comprising a solvent, a compound having an aromatic ring containing a hydroxy group, and an amine compound.

2. 2. The composition for black films according to claim 1, wherein the compound having an aromatic ring containing a hydroxy group is a compound having a naphthalene ring containing two or more hydroxy groups, and the compound having a naphthalene ring has hydroxy groups at the 1st and 2nd positions, the 1st and 3rd positions, the 1st and 5th positions, the 1st and 6th positions, the 1st and 7th positions, the 2nd and 3rd positions, the 2nd and 6th positions, or the 2nd and 7th positions.

3. The composition for a black film according to claim 1 or 2, further comprising polymethyl methacrylate.

4. A black film formed using the composition for black films according to claim 1 or 2.

5. Step 1: preparing a composition for a black film by adding a compound having an aromatic ring containing a hydroxyl group and an amine compound to a solvent and stirring the mixture; Step 2: curing the composition for black film at a constant temperature; Step 3: maintaining the black film composition in a film form; and step 4 of curing the black film composition maintained in a film form.

6. 6. The method for producing a black film according to claim 5, wherein the compound having an aromatic ring containing a hydroxy group is a compound having a naphthalene ring containing two or more hydroxy groups, and the compound having a naphthalene ring has hydroxy groups at the 1st and 2nd positions, the 1st and 3rd positions, the 1st and 5th positions, the 1st and 6th positions, the 1st and 7th positions, the 2nd and 3rd positions, the 2nd and 6th positions, or the 2nd and 7th positions.

7. The method for producing a black film according to claim 5 or 6, wherein polymethyl methacrylate is further added in step 1.

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