JP2018040932A - Optical filter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical filter that uses a glass substrate of 250 μm or less as a support, wherein the optical filter has excellent light selective transmitting properties, and excellent drop impact resistance.SOLUTION: An optical filter has a resin film containing a light selective absorbent to absorb light of a specific wavelength, the resin film put on a glass substrate. The glass substrate has a thickness of less than 0.25 mm and a breaking energy of 0.3 kgf mm or more. Preferably, the glass substrate has an elastic modulus of 65 GPa or less.SELECTED DRAWING: None

Description

  The present invention relates to a laminated type optical filter in which a light selective absorption resin film is laminated on a glass substrate, and more particularly to an optical filter having excellent drop impact resistance.

  For image sensor chips or solid-state image sensors built into video cameras, digital cameras, camera phones, tablet terminals with cameras, in-vehicle cameras, surveillance cameras, etc. An optical filter for reflecting the light is used.

Examples of the optical filter include a glass substrate type and a resin film type containing a compound capable of absorbing or reflecting light of a specific wavelength.
The resin film type is flexible and has the advantage of being strong against impact and bending, but it is easy to deform and color at high temperatures, so it is light-selective when used in in-vehicle cameras and surveillance cameras that are left in hot weather. There is a problem that the permeability is lowered and the durability as an optical filter is poor.
On the other hand, the glass substrate type is excellent in heat resistance, but has a problem relating to mechanical strength such that cracking or chipping easily occurs due to impact such as dropping. Under such circumstances, various studies have been made on optical filters that can satisfy both heat resistance and mechanical strength.

  For example, Japanese Patent Application Laid-Open No. 2008-181121 (Patent Document 1) discloses that flexibility can be imparted without impairing heat resistance by using a laminated type in which a resin film is laminated on a glass substrate. . In an example of Patent Document 1, a laminated film of a glass substrate and a resin film is used as a base material, and an optical filter in which a multilayer deposited film in which a silica film and a titania film are alternately deposited is formed on the base material, and It is disclosed that the optical filter has a heat resistance of 260 ° C. and the bending characteristics are superior to those when a glass substrate is used as the substrate.

  JP-A-2014-2414 (Patent Document 2) describes a resin film (norbornene-based resin film or polyimide-based resin) having a glass transition point of 70 ° C. or higher and a bending elastic modulus of 2400 MPa or higher instead of a glass substrate as a support. There has been proposed an optical filter in which a plurality of titania layers and silica layers are alternately laminated on both surfaces thereof.

Japanese Patent Laid-Open No. 2006-61792 (Patent Document 3) proposes a lens filter using a tempered glass plate (thickness 2 mm) as a substrate. Here, the tempered glass plate showed excellent strength in an impact resistance test for dropping a hard sphere, and as an antireflection film, the MgF ₂ layer stopped tensile stress and caused a decrease in impact resistance. It teaches that a decrease in impact resistance due to the MgF ₂ layer can be suppressed by laminating the ₂ O ₅ layer and the silica layer together.

JP 2008-181121 A JP 2014-2414 A JP, 2006-61792, A

  In the case of a glass substrate type optical filter, it can be considered that the problem of cracks and cracks, which are weak points of the glass substrate, can be solved by devising the laminated structure. In recent years, research on a laminated type optical filter in which a glass substrate is used as a support and a light selective transmission resin layer having a light absorption function and / or a light reflection function is laminated has been advanced.

  By the way, with recent reduction in size and weight of equipment, there is a high demand for thinning optical filters. With a thin film optical filter of 500 μm or less, there is a new problem that it is damaged after being incorporated into a product when it is mounted on a product even though cracks cannot be visually confirmed due to impact received during transportation or molding. found.

  An optical filter used in an image sensor chip incorporated in a camera-equipped mobile phone, a camera-equipped tablet terminal, or the like is cut into a size to be incorporated into a final product after a light selective absorption film or a vapor deposition film is laminated on a glass substrate. For this reason, even if it uses the tempered glass known as a glass which is strong against impact resistance and is hard to break, it is considered that the compressive force of the surface is released by the cut and the strengthening effect is lost. As a result, the optical filter that is the final product often has no impact resistance.

  The present invention has been made in view of the circumstances as described above, and an object thereof is to provide an optical filter using a glass substrate of 250 μm or less as a support, which has excellent light selective transmission characteristics and shock resistance. The object is to provide an optical filter having excellent properties.

  The inventor conducted various studies on the glass substrate, and in the case of a thin glass substrate having a thickness of 250 μm or less, further 150 μm or less, particularly 100 μm or less, not only the composition but also the impact and post-processing received during the transportation process, It was found that impact resistance as an optical filter finally formed is different. As a result of further studies, the present inventor has found that the breaking energy of the glass substrate used as the support is related to the cracks and cracks of the laminated optical filter, and thus completed the present invention.

  That is, the optical filter of the present invention is an optical filter in which a resin film containing a light selective absorbent that absorbs light of a specific wavelength is laminated on a glass substrate, and the glass substrate has a thickness of less than 0.25 mm. Thus, the glass substrate has a breaking energy of 0.3 kgf · mm or more. The glass substrate preferably has an elastic modulus of 65 GPa or less.

  The resin film containing the light selective absorbent is preferably a thermosetting resin film containing a light selective absorbent having a maximum absorption wavelength of light having a wavelength of 600 to 900 nm, and the film thickness of the resin film. Is preferably 0.5 to 15 μm. The resin film preferably further contains a silane coupling agent.

  A high refractive index material layer having a refractive index of 1.7 or more and a low refractive index material layer having a refractive index of 1.6 or less on the surface of the glass substrate on which the resin film is not laminated or on the resin film. It is preferable that light reflection films or antireflection films in which and are alternately laminated are further laminated.

  The optical filter of the present invention may be a near infrared ray or infrared cut filter using an oxocarbon compound as the light selective absorber.

  Since the optical filter of the present invention is a laminated type optical filter in which a light selective absorption resin film is laminated on a flexible and flexible glass substrate, it has excellent heat resistance and drop impact resistance.

FIG. 1 is a diagram for explaining a bending strength measurement test employed in the examples. FIG. 2 is a diagram for explaining a drop impact test employed in the examples.

  The optical filter of the present invention is an optical filter in which a light selective absorption resin film is laminated on a glass substrate, and the glass substrate has a thickness of less than 0.25 mm and a breaking energy of 0.3 kgf · mm or more. is there.

[Glass substrate]
The glass substrate used as the support of the optical filter of the present invention preferably has a thickness of less than 0.25 mm, more preferably less than 0.15 mm, and even more preferably less than 0.11 mm, in order to reduce the thickness of the product. . The thickness is preferably 0.1 mm or more, more preferably 0.3 mm or more, and even more preferably 0.7 mm or more, from the problem of warpage during product handling or vapor deposition.
The shape may be round or square.

Further, the breaking energy is 0.3 kgf · mm or more, preferably 0.5 kgf · mm or more, more preferably 0.7 kgf · mm or more.
The “breaking energy” referred to in the present specification is energy required for breaking as measured by a bending test.

  As the breaking energy of the glass substrate is larger, it is possible to provide an optical filter that is less susceptible to cracking due to impact, less likely to cause cracking, and thus less susceptible to cracking due to impact such as dropping.

  The glass substrate used in the present invention preferably has a flexural modulus of 65 GPa or less, more preferably 63 GPa or less, and still more preferably 62 GPa or less. Compared with a normal glass substrate, it is characterized by its flexibility.

  The kind of glass which comprises a glass substrate should just satisfy the said physical property, Soda lime glass, borosilicate glass, an alkali free glass, quartz glass, aluminosilicate glass, etc. can be used. Absorption type glass having absorption characteristics with respect to wavelength in the ultraviolet region and / or the (near) infrared region, for example, CuO added to fluorophosphate glass or phosphate glass may be used.

  In order to increase the glass strength, alkali metal ions (typically Li ions, Na ions) having a small ionic radius on the surface of the glass plate are exchanged by ion exchange at a temperature below the glass transition point. In the glass subjected to the chemical strengthening method for exchanging with (K ions), the glass surface layer has a compressive stress layer and the inside has a tensile stress layer. In this way, the tempering method that hardens the surface of the tempered glass (for example, about 9H in the pencil hardness test) makes it difficult to break, because the compressive stress is released by post-processing such as vapor deposition and cutting. The contribution of the strengthening effect to the filter is not high.

  The mechanical strength such as breaking energy and bending elastic modulus of the glass substrate can be changed by a cutting process for cutting out a predetermined size. Examples of the cutting method include dicing cut, laser cut, punching, and etching. If there are minute chips on the edge that cannot be visually identified, the breaking energy will be reduced and cracking will occur not only during user use but also during post-processing such as mounting to a mobile device or cutting to a specified size. Therefore, laser cutting and etching that are unlikely to cause minute chipping at the cut edge are preferable. However, since the glass substrate used in the present invention is relatively unaffected by the cutting method, cutting methods other than laser cutting and etching can be applied.

(Light selective absorption resin film)
The light selective absorption resin film of the optical filter of the present invention is a solidified (cured) body of a resin composition containing a light selective absorbent. Hereinafter, the resin composition used as the material of the light selective absorption resin film will be described.

(1) Resin composition (1-1) Base resin The base resin used in the resin fat composition forming the light selective absorption resin film can provide a highly transparent light selective absorption resin film for optical use. It is a resin that can uniformly dissolve or disperse the light selective absorbent.

  From this point of view, it is possible to use a composition of a thermoplastic resin having a glass transition point of 120 ° C. or higher, a heat or photocurable resin, but from the viewpoint of heat resistance, it is necessary to use a heat or photocurable resin. preferable.

Resins that are cured (polymerized) by heat or light include compounds having a curable functional group, such as oxirane groups (oxirane rings), oxetane groups (oxetane rings), ethylene sulfide groups, dioxolane groups, trioxolane groups, vinyl ether groups. A cation curable group such as a styryl group; a radical curable group such as an acryl group, a methacryl group or a vinyl group; a compound having a curable functional group such as
Here, a group containing an oxirane ring which is a three-membered ether is also referred to as an “epoxy group”. In the “epoxy group”, in addition to an epoxy group in a narrow sense, a group in which an oxirane ring is bonded to carbon such as a glycidyl group, a group including an ether bond or an ester bond such as a glycidyl ether group and a glycidyl ester group, An epoxy cyclohexane ring and the like are included.

  Of the curable resins that are cured by heat or light, a cation curable resin that generates a cationic species from the catalyst by heat or light and is cured by a cation curing reaction thereby is preferable. Cationic curing (polymerization) is advantageous in that it is less susceptible to curing inhibition by oxygen and has less shrinkage during curing than radical polymerization.

As the thermosetting resin, a polycyclic aromatic polymer, a polyimide resin, an epoxy resin, or the like can be used.
As the cationic curable thermosetting resin, an epoxy resin is particularly preferably used. Preferred examples of the epoxy compound that is a constituent monomer of the epoxy resin include alicyclic epoxy compounds, hydrogenated epoxy compounds, aromatic epoxy compounds, and aliphatic epoxy compounds. From the viewpoint of heat resistance and strength, (hydrogenated) aromatic epoxy resins and alicyclic epoxy resins are preferably used.

  Examples of the alicyclic epoxy group include an epoxycyclohexane group (epoxycyclohexane skeleton), an epoxy group added to a cyclic aliphatic hydrocarbon directly or via a hydrocarbon (particularly an oxirane ring), and the like. Moreover, the polyfunctional alicyclic epoxy compound which has two or more alicyclic epoxy groups in a molecule | numerator at the point which can raise a hardening rate more may be sufficient.

  Specifically, for example, YED-216D manufactured by Japan Epoxy Resin Co., Ltd., YL-7217 manufactured by Japan Epoxy Resin Co., Ltd. (epoxy equivalent 437, oxyalkylene chain is oxybutylene, liquid epoxy resin (10 ° C. or higher); high molecular weight Epoxy resin (for example, hydrogenated bisphenol (manufactured by Japan Epoxy Resin, YL-7170, epoxy equivalent 1000, solid hydrogenated epoxy resin); alicyclic solid epoxy resin (manufactured by Daicel Industries, EHPE-3150); alicyclic Examples thereof include liquid epoxy resins (Delcel Kogyo Co., Celoxide 2081), or mixtures thereof, of which, since they can be dissolved in a solvent and easily solidify by evaporation of the solvent, they are solid epoxy at room temperature. A resin is preferably used, and the coating film is easily solidified at room temperature. Sea urchin, a weight average molecular weight of 1,000 or more, more preferably 2000 or more. In order to improve the compatibility with a solvent, 1,000,000 preferably less weight-average molecular weight, more preferably 10,000 or less.

(1-2) Photoselective Absorber As the photoselective absorber, a dye having a π electron bond in the molecule is preferable. The dye having a π electron bond in the molecule is preferably a compound containing an aromatic ring. More preferred are compounds containing two or more aromatic rings in one molecule. In addition, as an optical filter, it is preferable that the pigment | dye which has (pi) electron bond in the said molecule | numerator has an absorption maximum in the wavelength range of 600-900 nm, ie, a specific pigment | dye. In the case of an infrared or near-infrared cut filter, it is preferable to have an absorption maximum in the wavelength region of 600 to 900 nm.

  Examples of the dye having a π bond in the molecule include phthalocyanine dyes, porphyrin dyes, cyanine dyes, nickel complex dyes, copper ion dyes, and the like, and one or more of these are used. can do. From the viewpoint of heat resistance and weather resistance, a dye having neither a zwitterionic structure nor a cationic structure is preferable, and phthalocyanine dyes and porphyrin dyes are particularly preferable, and phthalocyanine dyes are more preferable. Further, from the viewpoint of high transparency in the visible light region of 400 to 600 nm, high absorption coefficient of 600 to 1100 nm, and high weather resistance after vapor deposition, oxocarbon compounds such as squarylium dyes and croconium dyes are preferable. .

  The oxocarbon compound is a compound having an oxocarbon skeleton in the chemical structure. Specifically, a squarylium compound represented by the following formula (1) or a croconium compound represented by the following formula (2) is used. Used.

R ^S1 and R ^S2 in the formula (1), R ^C1 and R ^C2 in the formula (2) may be the same or different, and each independently represents a structure represented by the following (1a) or (2a) Unit.

  In formula (1a), ring A is a 4- to 9-membered, preferably 6- to 8-membered unsaturated hydrocarbon ring. X and Y are each independently an organic group or a polar functional group. n is an integer of 0 to 6, and when n is 2 or more, the plurality of Y may be the same or different. Ring B is an optionally substituted alicyclic heterocycle, aromatic heterocycle or a condensed ring containing these ring structures. In addition, * represents the coupling | bond part with the 4-membered ring in Formula (1) or the 5-membered ring in Formula (2).

  Examples of the structure of ring A include cyclobutene, cyclopentene, cyclopentadiene, cyclohexene, cyclohexadiene, cycloheptene, cycloheptadiene, cycloheptatriene, cyclooctene, cyclooctadiene, cyclooctatriene, cyclononene, cyclononadiene, cyclononatriene, Examples include cycloalkene structures such as cyclononatetraene. Of these, cycloalkane monoenes such as cyclopentene, cyclohexene, cycloheptene, and cyclooctene are preferable.

  Examples of the aromatic heterocyclic ring constituting the ring B include a 5- or 6-membered monocyclic aromatic heterocyclic ring containing at least one atom selected from a nitrogen atom, an oxygen atom and a sulfur atom, Examples thereof include condensed bicyclic or tricyclic condensed rings containing at least one atom selected from a nitrogen atom, an oxygen atom and a sulfur atom, and more specifically, a pyridine ring, a pyrazine Ring, pyrimidine ring, pyridazine ring, quinoline ring, isoquinoline ring, phthalazine ring, quinazoline ring, quinoxaline ring, naphthyridine ring, cinnoline ring, pyrrole ring, pyrazole ring, imidazole ring, triazole ring, tetrazole ring, thiophene ring, furan ring, Thiazole ring, oxazole ring, indole ring, isoindole ring, indazole ring, benzimidazole ring, benztri Tetrazole ring, benzothiazole ring, benzoxazole ring, purine ring, carbazole ring.

  As the alicyclic heterocycle, for example, a 5- or 6-membered monocyclic alicyclic heterocycle containing at least one atom selected from a nitrogen atom, an oxygen atom and a sulfur atom, and a 3- to 8-membered ring are condensed. A bicyclic or tricyclic condensed alicyclic heterocyclic ring containing at least one atom selected from a nitrogen atom, an oxygen atom and a sulfur atom, and more specifically, a pyrrolidine ring, a piperidine ring, Examples include piperazine ring, morpholine ring, thiomorpholine ring, homopiperidine ring, homopiperazine ring, tetrahydropyridine ring, tetrahydroquinoline ring, tetrahydroisoquinoline ring, tetrahydrofuran ring, tetrahydropyran ring, dihydrobenzofuran ring, tetrahydrocarbazole ring and the like.

  Examples of the aromatic ring or condensed ring constituting ring B include those having 6 to 14 carbon atoms, such as a benzene ring, a naphthalene ring, and an anthracene ring.

  The substituent of the heterocyclic ring or aromatic ring may be the same or different and may be 1 to 5 substituents such as hydroxyl group, carboxyl group, nitro group, alkoxy group, alkyloxycarbonyl group, amide group, sulfonamide group, alkyl Group, aralkyl group, cyano group, halogen atom, -R '= R "-Ar (R' and R" are the same and represent N or CH, Ar represents a hydroxyl group, a carboxyl group, a nitro group, an alkoxy group And an aryl group which may be substituted with a substituent selected from the group consisting of an alkyl group optionally substituted with a halogen group, a cyano group and a halogen atom). Examples of the substituent of the alkyl group or the alkoxy group include the same or different 1 to 3 substituents such as a hydroxyl group, a carboxyl group, a nitro group, an alkoxy group, an aryl group, and a halogen atom. Among them, a 5-membered or 6-membered heterocyclic ring which may have a substituent or a 5-membered or 6-membered aromatic ring which may have a substituent is preferable.

  (1a) In formula, n is an integer of 0-6, Preferably it is an integer of 0-5, More preferably, it is an integer of 0-3, More preferably, it is an integer of 0-2. When n is 1 or more, the hydrogen atom bonded to the carbon atom constituting the ring A is substituted with Y.

Examples of the organic group as X and Y include, for example, alkyl group, alkoxy group, alkylthiooxy group (alkylthio group), alkyloxycarbonyl group, alkylsulfonyl group, aryl group, aralkyl group, aryloxy group, arylthiooxy group (an arylthio group), an aryloxycarbonyl group, an arylsulfonyl group, an arylsulfinyl group, an amide group (-NHCOR), a sulfonamido group (-NHSO ₂ R), a carboxy group (carboxylic acid group), benzothiazole group, halogenoalkyl Group, cyano group and the like. Examples of the polar functional group include a halogeno group, a hydroxyl group, a nitro group, an amino group, and a sulfo group (sulfonic acid group).

  As the organic group or polar functional group as an example of X, among the above, an alkyl group, an alkyloxycarbonyl group, and an aryl group are preferable, and an alkyl group or an aryl group is more preferable. In this case, the number of carbon atoms of the alkyl group is preferably 1 to 6 if it is a linear or branched alkyl group, more preferably 1 to 4, and 4 to 7 if it is an alicyclic alkyl group. Preferably, it is 5-6. 6-10 are preferable and, as for carbon number of an aryl group, More preferably, it is 6-8. Specific examples include a methyl group, an ethyl group, an isopropyl group, an isobutyl group, a t-butyl group, a cyclopentyl group, a cyclohexyl group, and a phenyl group.

  As the organic group or polar functional group as an example of Y, among the above, an alkyl group, an alkoxy group, a halogeno group, a phenyl group, an alkoxycarbonyl group (ester group), an amide group, a sulfonamide group, and a hydroxyl group are preferable. An alkyl group or a hydroxyl group is preferable. In this case, 1-5 are preferable, as for carbon number of an alkyl group, More preferably, it is 1-3, More preferably, it is 1-2. Specifically, preferred examples of the organic group or polar functional group as Y include a methyl group, an ethyl group, and a hydroxyl group. When n is 2 or more, each Y may be the same or different.

In the formula (2a), R ¹ , R ² , R ⁴ and R ⁵ are each independently an organic group, a polar functional group or a hydrogen atom, and R ³ is an organic group or a polar functional group containing a nitrogen atom. , R ¹ and R ⁵ are at least one of an organic group or a polar functional group containing a nitrogen atom or an oxygen atom. In addition, * represents the coupling | bond part with the 4-membered ring in (1) Formula or the 5-membered ring in (2) Formula.

  A particularly preferred squarylium-based compound is that in the structural unit of formula (1), ring A is cyclohexene, cycloheptene, or cyclooctene, X is an alkyl group having 1 to 4 carbon atoms, and ring B is a benzene ring or naphthalene ring. It is a compound which is. In the particularly preferred squarylium compound, when ring B has a substituent, the substituent is preferably an alkyl group, a trihalogenomethyl group, a phenyl group, an alkoxy group, a cyano group, a carboxyl group, or a halogeno group.

The oxocarbon-based compound having the above-described configuration can be synthesized, for example, by the synthesis method described in the following paper.
SAJJADIFAR ET AL: 'New 3H-Indole Synthesis by Fischer's Method. Part I.' Molecules 2010, No. 15, April 2010, pages 2491-2498
Serguei Miltsov ET AL; 'New Cyanine Dyes: Norindosquarocyanines', Tetrahedron Letters, Volume 40, Issue 21, May 1999, pages 4067-4068

  In addition to the above paper, examples of the synthesis method for reacting a pyrrole ring-containing compound with croconic acid include, for example, JP-A No. 2002-286931, JP-A No. 2007-31644, JP-A No. 2007-31645, and JP-A No. 2007. Reference may be made to the method described in JP-A 169315.

  In addition to the above oxirane ring-containing compounds, as the light selective absorber, phthalocyanine dyes, cyanine dyes, porphyrin dyes, pyromethene dyes, azo dyes, quinone dyes, squarylium dyes, triarylmethane dyes Further, near-infrared absorbing compounds such as indigo dyes, copper ion dyes, and diimonium dyes may be used in combination.

  Such a light selective absorbent is preferably 50 parts by mass or less, and more preferably 20 parts by mass or less, from the viewpoint of solubility in a solvent per 100 parts by mass of the base resin. From the viewpoint of the amount of dye absorbed, it is preferably 1 part by mass or more, and more preferably 3 parts by mass or more.

(1-3) Curing Agent When the resin composition used in the present invention is a curable resin composition, it preferably contains a curing agent that accelerates the curing reaction of the curable resin. The curing agent is appropriately selected depending on the type of curable resin.

  When an acrylic resin is contained as the curable resin, radicals are generated by heating or light irradiation, and polymerization of a vinyl group such as a (meth) acryloyl group in the curable (meth) acrylic resin can be started. A radical polymerization initiator can be used.

  When an epoxy resin is used as the curable resin, an acid anhydride, an amine, a phosphine phenol (including a phenol resin), or a thiol can be used as the curing agent.

  The acid anhydride is preferably an alicyclic carboxylic acid anhydride, more preferably methyltetrahydrophthalic anhydride, tetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, hexahydrophthalic anhydride, more preferably Methylhexahydrophthalic anhydride and hexahydrophthalic anhydride.

  In the case of a cationic curable resin, it is preferable to use a combination of Lewis acid and Lewis base as the cationic curing catalyst.

  Specific examples of the Lewis acid include tris (pentafluorophenyl) borane (TPB), bis (pentafluorophenyl) phenylborane, pentafluorophenyl-diphenylborane, and tris (4-fluorophenyl) borane. TPB is more preferable because it can improve the heat resistance, moisture heat resistance, low water absorption, UV irradiation resistance and the like of the molded body.

The Lewis base is not particularly limited as long as it can be coordinated to the Lewis acid, that is, can form a coordinate bond with the boron atom of the Lewis acid. A compound having a sulfur atom can be used.
Preferred examples of the compound having a nitrogen atom include amines (monoamines and polyamines) and ammonia. More preferred are amines having a hindered amine structure, low boiling point amines, and ammonia. The compound having the phosphorus atom is preferably a phosphine. Specific examples include triphenylphosphine, trimethylphosphine, tritoluylphosphine, methyldiphenylphosphine, 1,2-bis (diphenylphosphino) ethane, and diphenylphosphine.
Preferred examples of the compound having a sulfur atom include thiols and sulfides. Specific examples of thiols include methyl thiol, ethyl thiol, propyl thiol, hexyl thiol, decane thiol, and phenyl thiol. Specific examples of the sulfides include diphenyl sulfide, dimethyl sulfide, diethyl sulfide, methylphenyl sulfide, methoxymethylphenyl sulfide and the like.

  The content of the curing agent is appropriately selected according to the type of base resin and the type of curing agent. When the base resin is an epoxy resin and a combination of Lewis acid and Lewis base is used as the cationic curing agent, the cationic curing agent is preferably contained in an amount of 0.1 to 10 parts by mass, more preferably 100 parts by mass of the base resin. It is 0.5-8 mass parts, More preferably, it is 1-5 mass parts.

(1-4) Silane coupling agent It is preferable that the resin composition used as the material of the light selective absorption resin film contains a silane coupling agent. When a resin composition in which an oxirane ring-containing compound is combined with an oxocarbon-based compound is used, it is difficult to produce a cured product excellent in both photoselective permeability and heat-and-moisture resistance of the resin composition, but a silane coupling agent By containing, it can be set as the hardened | cured material which was excellent in both selective permeability and heat-and-moisture resistance, and also can improve the adhesiveness with respect to a glass substrate.

  Examples of the silane coupling agent include mercapto group-containing silane coupling agents such as 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, and 3-mercaptopropylmethyldimethoxysilane; 3-aminopropyltrimethoxysilane, Amino group-containing silane coupling agents such as 3-aminopropyltriethoxysilane and 3-aminopropyltriisopropoxysilane; γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldimethoxysilane, γ- Epoxy ring-containing silane coupling agents such as (2,3-epoxycyclohexyl) propyltrimethoxysilane and γ-glycidoxypropyltrimethoxysilane; γ-methacryloxypropyltrimethoxysilane, γ-methacryloxy And unsaturated hydrocarbon group-containing silane coupling agents such as methyl dimethoxy silane can be used. Of these, an epoxy ring-containing silane coupling agent is particularly preferably used.

  The content of the silane coupling agent in the resin composition is preferably 0.01 parts by mass or more, more preferably 0.1 parts by mass or more, and still more preferably 0 per 100 parts by mass of the base resin from the viewpoint of imparting adhesion. .1 part by mass or more. Moreover, from a compatible viewpoint of resin, 50 mass parts or less are preferable, More preferably, it is 20 mass parts or less, More preferably, it is 10 mass parts or less.

(1-5) Mercapto group-containing compound The resin composition used in the present invention preferably further contains a mercapto group-containing compound. When using a resin composition that combines an oxocarbon-based compound and a curing catalyst, it is difficult to produce a cured product with sufficiently excellent selective permeability of the resin composition, but a combination of an oxocarbon-based compound and a curing catalyst. By including a mercapto group-containing compound in the resin composition, it is possible to obtain a cured product having sufficiently excellent selective permeability, and to further improve adhesiveness (particularly adhesion to a glass substrate). . That is, it can be used as a visible light transmittance improver. Moreover, it is thought that the production | generation of the coloring component which has absorption in a visible region is suppressed by containing a mercapto group containing compound in a resin composition.

  The mercapto group-containing compound may be a compound containing one or more mercapto groups in the compound, but is preferably a compound containing 2 to 6, more preferably 3 to 5. For example, β-mercaptopropionic acid, 2-ethylhexyl-3-mercaptopropionate, n-octyl-3-mercaptopropionate, methoxybutyl-3-methcaptopropionate, stearyl-3-mercaptopropio , Trimethylolpropane tris (3-mercaptopropionate), tris-[(3-mercaptopropionyloxy) -ethyl] isocyanurate, pentaerythritol tetrakis (3-mercaptopropionate), tetraethylene glycol bis (3- Β-mercaptopropionic acids such as mercaptopropionate), tetraethylene glycol bis (3-mercaptopropionate), and dipentaerythritol hexakis (3-mercaptopropionate) can be used. Among these, tris-[(3-mercaptopropionyloxy) -ethyl] isocyanurate (TEMPIC), pentaerythritol tetrakis (3-mercaptoprepionate) (PEMP), dipentaerythritol hexakis (3-mercaptopropionate) ) (DPMP) is preferred, and pentaerythritol tetrakis (3-mercaptoprepionate) (PEMP) is more preferred.

Moreover, you may use the mercapto group containing silane coupling agent represented by a following formula as a mercapto group containing compound.
HS-R-Si (OR ') _n (R ") _3-n
R is an alkyl group, preferably an alkyl group having 1 to 3 carbon atoms. R ′ is an alkyl group, an acetyl group, or a methoxyalkyl group, preferably a methyl group or an ethyl group, and more preferably a methyl group. R ″ is an alkyl group, preferably an alkyl group having 1 to 3 carbon atoms, more preferably a methyl group. N is 1 or more and 3 or less, preferably 3. A mercapto group-containing silane cup Specific examples of the ring agent include mercapto group-containing silane coupling agents exemplified for the silane coupling agent.

  The content of the mercapto group-containing compound per 100 parts by mass of the base resin is preferably 0.1 to 20 parts by mass, and more preferably 0.5 to 10 parts by mass.

(1-6) Surface Conditioner The resin composition may further contain a surface conditioner. By containing the surface conditioner, defects such as dents and striations in the formed resin film can be suppressed, and the homogeneity of the resin film surface can be improved.

  The surface conditioner is not particularly limited, and examples thereof include a siloxane-based surfactant, an acetylene glycol-based surfactant, a fluorine-based surfactant, and an acrylic leveling agent. A siloxane surfactant or an acrylic leveling agent is preferable, and a siloxane surfactant is more preferable.

  A siloxane-based surfactant is a surfactant having a siloxane bond (—Si—O—Si—), such as polyether-modified polydimethylsiloxane, alkyl-modified polydimethylsiloxane, polyester-modified polydimethylsiloxane, Examples include aralkyl-modified polydimethylsiloxane, and from the viewpoint of dispersibility of the oxocarbon-based compound in the resin composition, it is preferable that polyether-modified polydimethylsiloxane is included. The polyether-modified polydimethylsiloxane is preferably a nonionic surfactant having a hydrophilic group composed of polyalkylene oxide (more preferably ethylene oxide or propylene oxide) and a hydrophobic group composed of dimethylsiloxane.

  A commercially available product can also be used as the polyether-modified polydimethylsiloxane. Examples of commercially available products include BYK-306, BYK-307, BYK-330, BYK-331, BYK-337, BYK-344 (above, manufactured by BYK Chemie), KF-618, KF-351, KF-352, Examples thereof include KF-353, KF-6011, KF-6015 (manufactured by Shin-Etsu Chemical Co., Ltd.).

  Examples of the acetylene glycol surfactant include 2,4,7,9-tetramethyl-5-decyne-4,7-diol, 3,6-dimethyl-4-octyne-3,6-diol, 3, 5-dimethyl-1-hexyn-3-ol and the like.

  Examples of the fluorosurfactant include perfluoroalkyl sulfonate, perfluoroalkyl carboxylate, perfluoroalkyl phosphate, perfluoroalkyl ethylene oxide adduct, perfluoroalkyl betaine, and perfluoroalkylamine oxide compounds. Etc.

  Examples of the acrylic leveling agent include methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, n-propyl acrylate, n-propyl methacrylate, isopropyl acrylate, isopropyl methacrylate, n-butyl acrylate, n-butyl methacrylate, sec-butyl. A polymer obtained by polymerizing acrylate, sec-butyl methacrylate, isobutyl acrylate, isobutyl methacrylate, tert-butyl acrylate, tert-butyl methacrylate, allyl acrylate, allyl methacrylate, benzyl acrylate, benzyl methacrylate, cyclohexyl acrylate, cyclohexyl metallate, etc. Or a copolymer obtained by copolymerizing two or more types Door can be.

  The content of the surface conditioning agent per 100 parts by mass of the base resin is preferably 0.001 to 10 parts by mass, and more preferably 0.01 to 5 parts by mass.

(1-7) Other components The resin composition used in the present invention is a curing catalyst / curing agent other than the cationic curing catalyst, a curing accelerator, a reaction, as long as the effects of the present invention are not impaired. Diluent, saturated compound without unsaturated bond, pigment, dye, antioxidant, ultraviolet absorber, light stabilizer, plasticizer, non-reactive compound, chain transfer agent, thermal polymerization initiator, anaerobic polymerization initiation Agents, polymerization inhibitors, inorganic fillers, organic fillers, adhesion improvers such as coupling agents other than silane coupling agents, heat stabilizers, antibacterial / antifungal agents, flame retardants, matting agents, antifoaming agents , Leveling agents, wetting / dispersing agents, anti-settling agents, thickeners / anti-sagging agents, anti-coloring agents, emulsifiers, anti-slip / scratch agents, anti-skinning agents, desiccants, antifouling agents, antistatic agents, You may contain a electrically conductive agent (electrostatic adjuvant) etc.

(2) Solvent The resin composition used as the material of the light selective absorption resin film is usually preferably used as a resin solution dissolved in a solvent from the viewpoint of simply performing a coating operation on a glass substrate.

  The amount of the solvent in the resin solution is preferably 10% by mass or more, more preferably 30% by mass or more, and further preferably 50% by mass or more from the viewpoint of dissolving the material and spreading a uniform coating film during spin coating. For the same reason, the resin solid content in the resin solution is preferably less than 90% by mass, more preferably less than 70% by mass, and still more preferably less than 50% by mass. The amount of the solvent in the resin solution is preferably less than 95% by mass, more preferably less than 90% by mass, and even more preferably less than 80% by mass from the viewpoint of ensuring film formation in a short time and the thickness of the coating film. For the same reason, the resin solid content in the resin solution is preferably 5% by mass or more, more preferably 10% by mass or more, and further preferably 20% by mass or more.

  The solvent used in the present invention may be any solvent that can dissolve the resin composition as described above, and may be one kind of organic solvent or a mixture of two or more kinds of organic solvents. Also good.

  Usable organic solvents include, for example, toluene, xylene, benzene, ethylbenzene, tetralin, styrene, cyclohexane, dichloromethane, chloroform, ethyl chloride, 1,1,1-trichloroethane, 1-chlorobutane, cyclohexyl chloride, trans-dichloroethylene, Cyclohexanol, methyl cellosolve, n-propanol, n-butanol, 2-ethylbutanol, n-heptanol, 2-ethylhexanol, butoxyethanol, diacetone alcohol, benzaldehyde, γ-butyrolactone, acetone, methyl ethyl ketone, dibutyl ketone, methyl- i-butyl ketone, methyl-i-amyl ketone, cyclohexane, acetophenone, methylal, furan, β-β-dichloroethyl ether Dioxane, tetrahydrofuran, ethyl acetate, n-butyl acetate, amyl acetate, n-butyl acetate, cyclohexylamine, ethanolamine, dimethylformamide, acetonitrile, nitromethane, nitroethane, 2-nitropropane, nitrobenzene, dimethylsulfoxide, diethylene glycol dimethyl ether, diethylene glycol Examples thereof include monomethyl ether, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate (PGMEA), ethylene glycol monomethyl ether acetate, cyclohexanone, N-methylpyrrolidone and the like.

  Among these, for example, as a single organic solvent, toluene, xylene, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, cyclohexanone, as a mixed solvent combining two or more kinds, a combination of toluene and xylene, cyclohexane and xylene And the like.

(Preparation of resin solution)
Resin component as described above, light selective absorbent, curing agent as necessary, silane coupling agent added as necessary, surface conditioner, transmittance improver, other additives, predetermined ratio In this case, it may be dissolved in a solvent to form a liquid resin composition, or a solution in which a base resin and a light selective absorber are dissolved in a solvent are mixed, and various additives are added to the obtained mixture. May be.
In the case of a cationic curable resin composition, first, a base resin solution is prepared, and various additives such as a cationic curing catalyst, a photoselective absorber, and a surface conditioner may be added to and mixed with this solution. May be dissolved in a solvent to prepare each solution, and then the prepared solutions may be mixed.

  Each component is preferably used after being appropriately purified by known purification means such as filtration, silica gel column chromatography, alumina column chromatography, sublimation purification, recrystallization, and crystallization as necessary. For purification, it is preferable to use after removing foreign substances in the composition using a filter having a pore size of 0.1 μm or less.

  The amount of the solvent in the resin solution is preferably 10% by mass or more, more preferably 30% by mass or more, and further preferably 50% by mass or more from the viewpoint of dissolving the material and spreading a uniform coating film during spin coating. For the same reason, the resin solid content in the resin solution is preferably less than 90% by mass, more preferably less than 70% by mass, and even more preferably less than 50% by mass. The amount of the solvent in the resin solution is preferably less than 95% by mass, more preferably less than 90% by mass, and still more preferably less than 80% by mass from the viewpoint of film formation in a short time and securing of the coating film thickness. For the same reason, the resin solid content in the resin solution is preferably 5% by mass or more, more preferably 10% by mass or more, and further preferably 20% by mass or more.

[Manufacture of optical filters]
An optical filter can be manufactured by applying the resin composition (or resin solution) as described above on the glass substrate, drying and curing, and forming a light selective absorption resin film. The film forming method on the glass substrate is not particularly limited, and can be performed by a spin coating method, a bar coating method, or the like, but from the viewpoint that a thin film with high uniformity in film thickness can be efficiently created. A spin coating method is preferably employed.

  Spin coating conditions, that is, rotation speed, rotation time, time from the start of rotation until reaching the maximum rotation speed (acceleration time), time from the maximum rotation speed to rotation stop (deceleration time), spin coater, substrate size, It is appropriately selected depending on the shape of the substrate, the composition of the resin composition, and the like. Usually, in the case of a circular substrate, the maximum rotation speed is 500 to 4000 rpm, the rotation duration time at the maximum rotation speed is 0.5 to 30 seconds, the acceleration time to the maximum rotation speed is 0.01 to 3 seconds, and the rotation speed is from the maximum rotation speed to the rotation stop. The deceleration time is 0.01 to 3 seconds. In the case of a square substrate, when an open system is used, the maximum rotation speed is 500 to 4000 rpm, the rotation duration at the maximum rotation speed is 0.5 to 30 seconds, and the acceleration time to the maximum rotation speed is 0.01 to 3 seconds. The deceleration time from the maximum rotation speed to the rotation stop is 0.01 to 3 seconds.

Dry after coating. In the case of a curable resin, a curing step is performed.
As thermosetting, it is preferable to cure at about 30 to 400 ° C., and as photocuring, it is preferable to cure at 10 to 10,000 mJ / cm ² . From the viewpoint of increasing the curability of the resin, the curing temperature is preferably 100 ° C. or higher, more preferably 130 ° C. or higher, and further preferably 150 ° C. or higher. On the other hand, from the viewpoint of suppressing deterioration of the dye, the heat curing temperature is preferably less than 300 ° C, more preferably less than 250 ° C, and even more preferably less than 230 ° C. Moreover, it is preferable that it is 1 minute or more from a viewpoint of raising the sclerosis | hardenability of resin, More preferably, it is 10 minutes or more, More preferably, it is 30 minutes or more.

The heat curing conditions are appropriately set according to the composition of the resin composition to be used.
In the case of a combination of an epoxy resin and a curing agent, it is kept at 80 to 300 ° C., preferably 100 to 250 ° C. for about 30 minutes to 2 hours to completely cure and completely evaporate the solvent.

The heat curing step is performed by leaving it in a heating oven.
It is preferable from the viewpoint of production efficiency that a plurality of the produced resin film laminated substrates are collectively heat-cured. For example, it is preferable that the substrate is left standing in an oven with the substrate standing vertically. From the viewpoint of preventing impurities such as dust and dust and foreign matter from adhering to the formed coating film, it is preferable to carry out heat curing in a vertically standing state.
In view of performing the heat curing step in a vertically standing state, it is preferable that the resin film be in a state without fluidity before being put in the oven.

  The heat curing step is preferably performed in an inert gas atmosphere such as nitrogen, and more preferably, a nitrogen stream is introduced into the system or gas replacement in the oven is performed with an inert gas, followed by heat curing. It is preferable. Thereby, modification | denaturation of the light selective absorber in a heat-hardening process can be prevented.

The thickness of the light selective absorption resin film formed as described above is not particularly limited, but is preferably, for example, 0.5 μm or more and 15 μm or less, and more preferably 1 μm or more and 10 μm or less. Even with such a thin film, a drop impact resistance can be satisfied as an optical filter by using a glass substrate having a breaking energy of 0.3 kgf · mm or more. Further, by using a cured film of a cationic curable resin composition containing an oxocarbon-based compound and an oxirane ring-containing compound as a light selective absorption resin film, excellent selective transmittance in the near infrared wavelength region can be secured. .
For example, by using a cation curable resin as the base resin and using an oxocarbon compound as the light selective absorber, the spectral light transmittance at a wavelength of 500 nm is 89% or more (preferably 89.5% or more, more The transmittance of spectral light at a wavelength of 700 nm is preferably 25% or less (preferably 22% or less, more preferably 20% or less).

An underlayer may be interposed between the glass substrate and the light selective absorption resin film.
The underlayer is preferably formed from an underlayer composition containing a silane coupling agent having an amino group, an epoxy group, or a mercapto group. When it is formed from the composition containing the silane coupling agent which has an amino group, it is preferable that it is a silane coupling agent which has a primary amino group. When using a composition for an underlayer containing a silane coupling agent having a primary amino group, the adhesiveness to the glass substrate is much higher than when containing a silane coupling agent having an amino group other than the primary amino group. It will be good. The liquid medium is preferably at least one selected from water, ethanol, and isopropyl alcohol. By adding a liquid medium to the silane coupling agent, an amino group, an epoxy group, or an alkoxy group in the silane coupling agent is hydrolyzed to form a silanol group, and this silanol group is dehydrated with a hydroxyl group on the glass substrate surface. Through the condensation reaction, a strong covalent bond can be generated with the glass substrate surface, whereby the adhesion between the glass substrate and the underlayer can be improved. The catalyst may be any one that acts as a catalyst during the hydrolysis reaction of an amino group, an epoxy group, or a silane coupling agent, and may be either an organic acid or an inorganic acid, but formic acid is used. preferable.

The optical filter of the present invention further comprises a layer having antireflection and / or antiglare properties, a layer having anti-scratch performance, and a layer other than the above on the light selective absorption resin film, which reduces reflection of a fluorescent lamp or the like. A layer having a function may be stacked.
Further, a reflection film that reflects light of a specific wavelength and / or an antireflection film that prevents reflection of specific light may be laminated.

  As the reflection film (or antireflection film), it is preferable to use a dielectric multilayer film in which high refractive index material layers and low refractive index material layers are alternately laminated. As a material constituting the high refractive index material layer, a material having a refractive index of 1.7 or more can be used, and a material having a refractive index range of 1.7 to 2.5 is usually selected. Examples of the material constituting the high refractive index material layer include oxides such as titanium oxide, zinc oxide, zirconium oxide, lanthanum oxide, yttrium oxide, indium oxide, niobium oxide, tantalum oxide, tin oxide, and bismuth oxide; silicon nitride Nitrides such as oxides, mixtures of the nitrides and the like, and those doped with metals or carbon such as aluminum or copper (for example, tin-doped indium oxide (ITO), antimony-doped tin oxide (ATO)), etc. Can be mentioned. As a material constituting the low refractive index material layer, a material having a refractive index of 1.6 or less can be used, and a material having a refractive index range of 1.2 to 1.6 is usually selected. Examples of the material constituting the low refractive index material layer include silicon dioxide (silica), alumina, lanthanum fluoride, magnesium fluoride, and aluminum hexafluoride sodium. By adjusting the kind, the number of layers, and the film thickness of these low-refractive materials and high-refractive materials, a light reflection film (or antireflection film) in a specific wavelength region can be obtained.

  In the optical filter of the present invention, a specific light reflection film, antireflection film, or other layer may be laminated on one side or both sides of the light selective absorption resin film laminated glass substrate as necessary. When laminating on one side, it may be laminated on the light selective absorption resin film or on the surface (on the glass substrate) on which the light selective absorption resin film is not laminated.

  The optical filters with the above configuration are visible light cut filter, infrared cut filter, near infrared cut filter, security filter, heat ray blocking / heat ray absorption filter, band pass filter, (day & night) surveillance camera filter, dark filter It can be suitably used as a filter for visual camera, a dual band filter, a filter for visible light image sensor / infrared sensor, and a light cut filter that causes problems with sensors such as neon light / fluorescence.

  The present invention will be described in more detail with reference to the following examples. However, the present invention is not limited to these examples. Note that “%” means “mass%” unless otherwise specified.

[Measurement and evaluation method]
(1) Elastic modulus, breaking energy Thickness x length x width 0.1 mm x 50 mm x 20 mm evaluation glass substrate is set in an Instron bending tester (Instron 1185 type) as shown in FIG. Then, a bending test was performed by loading a fulcrum plate made of polycarbonate with a diameter of 1 mm at a bending speed of 3 mm / min (the end surface was R-treated), the maximum bending deflection at break, the maximum bending strain, the bending elastic modulus ( Young's modulus) and breaking energy were measured.
In FIG. 1, reference numeral 1 denotes a glass substrate, and the glass substrate 1 is supported by polycarbonate plates 2 and 2 having a thickness of 1 mm whose end surfaces are R-treated. In this state, a load was applied in the direction of the arrow.

(2) Drop impact test The light selective absorption film laminated glass substrate was cut by dicing to obtain a 10 mm square test piece.
As shown in FIG. 2, four corners (1 mm square) of the test piece 6 were fixed with an adhesive 7 on a casing 5 having a length × width × height of 100 mm × 50 mm × 15 mm and 150 g. The casing 5 to which the test piece 6 was fixed was naturally dropped from a height of 1.5 m with the surface on which the test piece 6 was not placed being the ground side. This natural fall was repeated 10 times so that the test piece did not touch the ground directly, and the case where no crack occurred in the light selective absorption film laminated glass substrate was evaluated as “OK”, and the case where the crack occurred was evaluated as “NG”. did.

[Production of optical filter]
<Glass substrate>
By changing the composition and cutting method (laser cutting or dicing cut), as shown in Table 1, three types (A, B, C) of glass substrates having different bending characteristics were used. The size of the glass substrate is thickness × length × width = 0.1 mm × 76 mm × 76 mm.

<Preparation of resin solution>
(1) Cationic curing catalyst (1-1) TPB-containing powder (Lewis acid)
In accordance with a synthesis method described in WO1997 / 031924, 255 g of Isopar (registered trademark) E solution manufactured by Ando Parachemi with a TPB (tris (pentafluorophenyl) borane) content of 7% was prepared.
When water was dropped into the Isopar E solution at 60 ° C., white crystals were precipitated from the middle of dropping. After cooling the reaction solution to room temperature, the resulting slurry was filtered with suction and washed with n-heptane. The obtained cake was dried at 60 ° C. under reduced pressure, and 18.7 g of TPB / water complex (TPB-containing powder) as white crystals was obtained. This complex had a water content of 9.2% (Karl Fischer moisture meter) and a TPB content of 90.8%.
The complex after drying was subjected to ¹⁹ F-NMR analysis and GC analysis, but no peak was detected other than TPB. The results of ¹⁹ F-NMR analysis are as follows.

¹⁹ F-NMR (CDCl ₃ ) ppm (standard substance CFCCl ₃ 0 ppm)
δ = −135.6 (6F, m)
δ = -156.5 (3F, dd)
δ = −163.5 (6F, d)

(1-2) Preparation of Cationic Curing Catalyst A combination of the above TPB-containing powder (Lewis acid) and ammonia as a Lewis base was mixed as follows to prepare a cationic curing catalyst.
To 2 g of TPB-containing powder (TPB pure content: 1.816 g (3.547 mol) and water 0.184 g (10.211 mmol), 1.1 g of toluene was added and mixed at room temperature for 10 minutes.
To the obtained toluene solution of TPB, 2.6 g of a 2 mol / L ammonia / ethanol solution was added and mixed at room temperature for 60 minutes. The obtained homogeneous solution was used as a cationic curing catalyst.

上記スクアリリウム化合物は、ピロール環含有化合物とスクアリン酸とを反応させる公知の合成方（例えば、すでに述べた論文に記載の方法）によって合成することができる。 (2) Near-infrared absorber As a near-infrared absorber, the squarylium compound which has a structure of following (3) Formula was used. The maximum absorption wavelength of this squarylium compound is 730 nm.

The squarylium compound can be synthesized by a known synthesis method in which a pyrrole ring-containing compound and squaric acid are reacted (for example, the method described in the paper already described).

(3) Silane coupling agent solution 4 parts of silane coupling agent (Tos Dow Corning ofs-6040 (3-glycidoxypropyltrimethoxysilane which is conventional Z-6040)), 2-propanol (Wako Pure) 5.2 parts of drug), 0.6 part of pure water (manufactured by Wako Pure Chemical Industries), and 0.2 part of formic acid were mixed at 25 ° C. for 90 minutes to obtain a uniform solution of the silane coupling agent.

(4) Preparation of spin coat resin solution As the base resin, an alicyclic epoxy resin (EHPE3150) manufactured by Daicel Corporation, which is an oxirane compound, was used. 100 parts of base resin was mixed with 150 parts of toluene (manufactured by Wako Pure Chemical Industries, Ltd.) and 75 parts of o-xylene at 80 ° C.
In this resin solution, 9 parts of the squarylium compound synthesized above, 0.4 part of BYK-306 (polyether-modified polydimethylsiloxane) manufactured by Big Chemie as a surface conditioner, and PEMP manufactured by SC Organic Chemical Co., Ltd. as a transmittance improver 10 parts (pentaerythritol tetrakis (3-mercaptopropionate), see formula below) were added and mixed at 25 ° C. for 5 minutes to obtain a uniform solution. To this solution, 2.5 parts of the cation curing catalyst prepared above was added and then filtered through a 0.1 μm pore size filter (Whatman 6784-2501, manufactured by GE Helthcare) to remove foreign substances.

  346.9 parts of the obtained filtrate and 10 parts of the silane coupling solution prepared above were mixed at 25 ° C. for 30 minutes. The obtained uniform solution was filtered through a 0.1 μm filter (Whatman 6784-2501, manufactured by GE Helthcare) to remove foreign matters, thereby obtaining a resin solution to be used for spin coating.

[Formation of light selective absorption resin film]
As a coating apparatus, a spin coater (MS-A200 manufactured by Mikasa Corporation) was used.
0.8 g of the coating resin solution prepared above was dropped onto each of three types of glass substrates A, B, and C having different bending characteristics, and spin-coated. The spin coating conditions were as follows: acceleration to 0.1800 rpm in 0.1 seconds, 1800 rpm was held for 1 second, and then rotation was stopped (0 rpm) in 0.1 seconds.

  The glass substrate on which the light selective absorption resin film is laminated is placed in an inert oven (CL0-9CH of Koyo Thermo Systems Co., Ltd.), and the inside of the oven is purged with nitrogen for 30 minutes at room temperature (oxygen concentration 100 ppm or less (volume basis)) The temperature was raised to 200 ° C. in 30 minutes, and the temperature was maintained. After holding at 200 ° C. for 30 hours, the temperature was lowered to 150 ° C. in 30 minutes, and the light selective absorption film laminated glass substrate (light selective absorption film laminate) was taken out. Thus, an optical filter was obtained. The optical filter (the thickness of the light selective absorption resin film laminated glass) is 0.1 mm (the thickness of the light selective absorption resin film: about 2 μm).

[Evaluation of optical filter]
The optical film no. The above-described drop impact test was performed on 1 to 3. The evaluation results are shown in Table 1.

From Table 1, optical filter No. using a glass substrate C having a breaking energy of 0.3 kgf · mm or more and an elastic modulus of 65 GPa or less. No. 3 did not generate a crack even when a drop test was performed, but optical filter No. 3 using a glass substrate having a breaking energy of 0.3 kgf · mm or less. 1 and 2 were cracked in the drop test.
From the above results, even when a thin optical filter with a thickness of 0.1 mm is used as a glass substrate with a breaking energy of 0.3 kgf · mm or more, the impact when it is incorporated into a product And has crack resistance.
In addition, for laminated optical filters using a glass substrate, a light selective absorption resin film was laminated as a technique to prevent cracks and cracks from being caused by impacts such as transportation, post-processing, and impact received when incorporated into products. Using the breaking energy of the glass substrate as an index, it is also possible to sort out defective glass substrates that could not be identified visually.

[Preparation of optical filter with deposited film]
No. above. 3. On the surface opposite to the side on which the resin film of the optical filter 3 is formed, an alternate vapor deposition film (infrared reflective film) of 25 layers of titanium oxide / 26 layers of silica is formed, and 2 layers of titanium oxide / An alternating vapor deposition film (visible light antireflection film) of three layers of silica was formed. Thereby, a good infrared reflection absorption type infrared cut filter for an imaging device was obtained.

  The optical filter of the present invention is a thin film having a glass substrate with excellent heat resistance as a support, excellent in drop impact resistance, and excellent in light selective transmission performance. It is useful as an optical filter used for an image sensor chip or a solid-state imaging device built in a mobile device such as a tablet terminal with a camera. In addition, since it uses a flexible glass substrate and is an optical filter excellent in impact resistance, it has high versatility for post-processing, and is excellent in productivity including mounting to a final product.

Claims (7)

An optical filter in which a resin film containing a light selective absorbent that absorbs light of a specific wavelength is laminated on a glass substrate,
An optical filter, wherein the glass substrate is a glass substrate having a thickness of less than 0.25 mm and a breaking energy of 0.3 kgf · mm or more.   The optical filter according to claim 1, wherein the glass substrate has an elastic modulus of 65 GPa or less.   The optical filter according to claim 1 or 2, wherein the resin film containing the light selective absorbent is a thermosetting resin layer containing a light selective absorbent having a maximum absorption wavelength of light having a wavelength of 600 to 900 nm.   The optical filter according to claim 1, wherein the resin film has a thickness of 0.5 to 15 μm.   The optical filter according to claim 1, wherein the resin film further contains a silane coupling agent.   A high refractive index material layer having a refractive index of 1.7 or more and a low refractive index material layer having a refractive index of 1.6 or less on the surface of the glass substrate on which the resin film is not laminated or on the resin film. The optical filter according to any one of claims 1 to 5, wherein a light reflection film or a light reflection prevention film in which and are alternately laminated is further laminated.   The optical filter according to any one of claims 1 to 6, wherein the light selective absorbent is an oxocarbon-based compound and is used for near infrared rays or infrared rays.

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