JP6629508B2 - Infrared absorption filter - Google Patents

Description

  The present invention relates to an infrared absorption filter, and more particularly to an infrared absorption filter that can cut off infrared rays in the near infrared region.

  2. Description of the Related Art In recent years, in various fields such as optical devices such as display devices and image pickup devices, materials having a laminated structure in which various layers are formed on a substrate made of glass or the like have been widely used in order to achieve multifunction. As a layer formed on the substrate, for example, an ITO (tin-doped indium oxide) transparent conductive layer used for a touch panel or the like, an antireflection layer for reducing reflection of light on the substrate surface, and reducing optical noise in an imaging device (near ) Infrared absorbing layer and the like.

  The imaging device is also called a solid-state imaging device or an image sensor chip, and is an electronic component that converts light of a subject into an electric signal and outputs the electric signal. The imaging device is used, for example, for a mobile phone camera, a digital camera, a vehicle-mounted camera, a surveillance camera, a display device (eg, an LED), and the like. Such an image sensor usually has a configuration including a detection element (sensor) such as a charge coupled device (CCD) or a complementary metal-oxide semiconductor (CMOS) and a lens. It is required to reduce optical noise (especially noise in the near-infrared region) that hinders the operation.

  Various types of infrared absorption filters for reducing noise in the near infrared region are known. For example, Patent Document 1 discloses an infrared absorption filter in which a layer formed from a resin composition containing an oxirane compound having a hydroxyl group and / or an ester group and a phthalocyanine-based compound is provided on a glass substrate, Patent Document 2 discloses an infrared absorption filter having a glass substrate, a base layer mainly composed of silicon oxide, and a near infrared absorption layer containing a transparent resin and a near infrared absorption dye in this order.

JP 2014-149514 A JP 2014-052431 A

  In an infrared absorption filter having an infrared absorption layer formed on a glass substrate, it is important to ensure adhesion between the infrared absorption layer and the glass substrate. This is because if a gap is formed between the infrared absorbing layer and the glass substrate, the refractive index changes and desired optical performance cannot be obtained. In this case, it is preferable that the adhesion between the infrared absorbing layer and the glass substrate be maintained even in hot summer or in a high humidity environment.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an infrared absorption filter in which an infrared absorption layer is provided on a glass substrate. An object of the present invention is to provide an infrared absorption filter that is hardly peeled off from a glass substrate and that ensures adhesion between the infrared absorption layer and the glass substrate.

  The infrared absorption filter of the present invention that can solve the above problems is a glass substrate, an infrared absorption filter having an infrared absorption layer provided on the glass substrate, wherein the infrared absorption layer is a cycloolefin-based It is characterized by being formed from a resin composition containing a resin, a phthalocyanine-based compound having less than 8 ester bonds in a molecule or having no ester bond, and a silane coupling agent having an amino group. . The infrared absorption filter of the present invention is an infrared absorption filter having a glass substrate and an infrared absorption layer provided on the glass substrate, wherein the infrared absorption layer has a cycloolefin resin and an ester bond in one molecule. A binder layer formed from a resin composition containing less than 8 or a phthalocyanine compound having no ester bond is provided between the infrared absorbing layer and the glass substrate, and a binder layer formed from a silane coupling agent having an amino group is provided. May be used.

  The infrared absorbing layer containing a cycloolefin-based resin and a phthalocyanine-based compound, as it is, has insufficient adhesion to a glass substrate as it is, and is particularly easy to peel off from the glass substrate under high temperature and high humidity conditions. In the infrared absorption filter, the silane coupling agent having an amino group was contained in the infrared absorption layer or formed from a silane coupling agent having an amino group in order to enhance the adhesion between the infrared absorption layer and the glass substrate. After the binder layer is provided between the infrared absorbing layer and the glass substrate, a phthalocyanine compound having less than eight ester bonds in one molecule or having no ester bond is used as the phthalocyanine compound. With the infrared absorption filter of the present invention configured as described above, the infrared absorption layer is less likely to peel off from the glass substrate even under severe conditions of high temperature and high humidity, and the adhesion to the glass substrate can be improved.

  The phthalocyanine-based compound preferably has no ester bond, and is preferably a compound represented by the following formula (3). Further, the phthalocyanine-based compound preferably has an absorption maximum wavelength in a wavelength range of 600 nm to 900 nm.

[In the formula (3), M represents a metal atom, a metal oxide or a metal halide, and R ^{1a to} R ^1d , R ^{2a to} R ^2d , R ^{3a to} R ^3d and R ^{4a to} R ^4d are the same or different. Differently, it represents a hydrogen atom, a halogen atom, an optionally substituted alkoxy group, or an optionally substituted aryloxy group. ]

  The cycloolefin-based resin preferably has a repeating unit represented by the following formula (1) or the following formula (2).

[In the formula (1), m represents an integer of 0 to 3, and R ^{11 to} R ¹⁴ are the same or different and are each a hydrogen atom, a halogen atom, an alkyl group, a cycloalkyl group, an alkenyl group, an alkynyl group, an alkoxy group. , An alkoxyalkyl group, an alkoxycarbonyl group, or an alkoxycarbonylalkyl group. ]

[In the formula (2), n represents an integer of 0 to 3, and R ^{21 to} R ²⁴ are the same or different and each represent a hydrogen atom, a halogen atom, an alkyl group, a cycloalkyl group, an alkenyl group, an alkynyl group, an alkoxy group. , An alkoxyalkyl group, an alkoxycarbonyl group, or an alkoxycarbonylalkyl group. ]

  The silane coupling agent having an amino group is preferably a silane coupling agent having a primary amino group, whereby the adhesion between the infrared absorbing layer and the glass substrate is easily increased.

  The present invention also provides a cycloolefin-based resin, a phthalocyanine-based compound having less than 8 ester bonds or no ester bond in one molecule, and a silane cup having an amino group. A resin composition containing a ring agent, or a cycloolefin-based resin used to form an infrared absorbing layer, and a phthalocyanine-based compound having less than 8 ester bonds or having no ester bond in one molecule; And a resin composition containing the same. By using such a resin composition, an infrared absorbing layer containing a cycloolefin-based resin and a phthalocyanine-based compound can be formed on a glass substrate with good adhesion. The present invention also provides an imaging device having the infrared absorption filter of the present invention.

  In the infrared absorbing filter of the present invention, the infrared absorbing layer hardly peels off from the glass substrate even under conditions of high temperature and high humidity, and has excellent adhesion between the infrared absorbing layer and the glass substrate.

  The infrared absorption filter of the present invention has a glass substrate and an infrared absorption layer provided on the glass substrate. In the infrared absorbing layer, a cycloolefin-based resin known as a highly transparent resin is used, and a phthalocyanine-based compound capable of absorbing a wavelength in an infrared region is blended in the resin. The infrared absorbing filter of the present invention, even under conditions of high temperature and high humidity, in order to make the infrared absorbing layer difficult to peel off from the glass substrate, using a specific phthalocyanine-based compound, further as a binder between the infrared absorbing layer and the glass substrate, A specific silane coupling agent is used. Specifically, a phthalocyanine compound having less than 8 ester bonds in one molecule or having no ester bond is used as the phthalocyanine compound, and a silane coupling agent having an amino group is used as a binder. The infrared absorbing filter of the present invention having such a configuration can enhance the adhesion between the infrared absorbing layer and the glass substrate, and can increase the durability. Hereinafter, the infrared absorption filter of the present invention will be described in detail.

  The glass substrate is used as a support for the infrared absorption layer, and may be used without any particular limitation as long as it is a transparent (ie, light-transmitting) plate-like glass. The glass used for the glass substrate is preferably one containing silicon dioxide as a main component, and is preferably one in which silicon atoms and oxygen atoms form a network structure. Glass may contain atoms or ions other than silicon and oxygen, for example, sodium, potassium, calcium, magnesium, barium, boron, aluminum, iron, silver, copper, cobalt, nickel, lead, zinc, etc. May be included.

  By using a glass substrate, an infrared absorption filter having excellent heat resistance can be obtained. The infrared absorption filter thus obtained can be mounted on an electronic component by, for example, solder reflow. Further, even if the glass substrate is exposed to a high temperature, it is difficult for the glass substrate to crack or warp. Therefore, it is easy to secure the adhesion to the infrared absorbing layer.

  By using a glass substrate, a thin and high-intensity infrared absorption filter can be obtained. Therefore, when the infrared absorption filter is applied to an electronic component such as an optical device, the size of the electronic component can be reduced. The thickness of the glass substrate is, for example, preferably 0.05 mm or more, more preferably 0.1 mm or more, from the viewpoint of securing strength, and preferably 0.4 mm or less, more preferably 0.3 mm or less, from the viewpoint of thinning. preferable.

  The infrared absorption layer is provided on a glass substrate and contains at least a cycloolefin-based resin and a phthalocyanine-based compound. It is preferable that the phthalocyanine-based compound is dispersed or dissolved in the cycloolefin-based resin, and is substantially uniformly mixed with the cycloolefin-based resin in the infrared absorption layer.

  By the way, simply applying a cycloolefin-based resin on a glass substrate makes it difficult to obtain sufficient adhesion enough to withstand practical use. In particular, under severe conditions of high temperature and high humidity, the cycloolefin-based resin easily peels off from the glass substrate. Therefore, the present inventors have conducted various studies on a method for improving the adhesion of a infrared absorbing layer containing a cycloolefin resin and a phthalocyanine compound to a glass substrate, and as a phthalocyanine compound, an ester bond was formed in one molecule. By using a phthalocyanine-based compound having less than 8 or having no ester bond and further using a silane coupling agent having an amino group as a binder, even under conditions of high temperature and high humidity, the infrared absorbing layer is difficult to peel off from the glass substrate. It turned out to be. The silane coupling agent having an amino group may be present in the infrared absorbing layer, and the silane coupling agent having an amino group may be used to separate a binder layer different from the infrared absorbing layer into the infrared absorbing layer and the glass substrate. It may be formed between. The infrared absorbing layer containing the cycloolefin-based resin and the phthalocyanine-based compound can be suitably fixed to the glass substrate by the silane coupling agent having an amino group.

  That is, the infrared absorption filter of the present invention has a glass substrate and an infrared absorption layer provided on the glass substrate, and the infrared absorption layer has a cycloolefin resin and eight ester bonds in one molecule. And a phthalocyanine compound having less than or no ester bond, and fixed to the glass substrate by a silane coupling agent having an amino group. Specifically, the infrared absorption filter has a glass substrate and an infrared absorption layer provided on the glass substrate, and the infrared absorption layer has a cycloolefin-based resin and less than eight ester bonds in one molecule. Or is formed from a resin composition containing a phthalocyanine-based compound having no ester bond, the resin composition further contains a silane coupling agent having an amino group, or from a silane coupling agent having an amino group The formed binder layer is provided between the infrared absorbing layer and the glass substrate. ADVANTAGE OF THE INVENTION According to the infrared absorption filter of this invention, an infrared absorption layer is suitably fixed to a glass substrate, and it can make it hard to peel off an infrared absorption layer from a glass substrate.

  The cycloolefin-based resin is a (co) polymer obtained by using cycloolefin as at least a part of a monomer component and polymerizing the same, and has an alicyclic structure in a part of a main chain. Since the cycloolefin resin has a bulky alicyclic structure in the molecular skeleton of the main chain, the steric hindrance is large and the polymer chains are difficult to arrange. Therefore, the cycloolefin-based resin is hardly crystallized and has excellent transparency. Further, the cycloolefin-based resin has excellent weather resistance. Therefore, by forming the infrared absorbing layer from a cycloolefin resin, an infrared absorbing filter having high light transmittance and excellent weather resistance can be obtained.

  The cycloolefin-based resin may be a (co) polymer in which a monomer component is composed of one or more cycloolefins, or a copolymer containing a cycloolefin and another monomer as monomer components. You may. When the cycloolefin-based resin is a copolymer, the copolymer may be a random copolymer, a block copolymer, or an alternating copolymer.

  The cycloolefin-based resin preferably has a repeating unit represented by the following formula (1) or the following formula (2). Since the cycloolefin-based resin having the repeating unit represented by the formula (1) or (2) uses norbornenes having high reactivity as a cycloolefin as a monomer component, the production of the cycloolefin-based resin is facilitated. As the polymerization reaction of norbornenes, addition polymerization (including addition copolymerization with other olefins) and ring-opening metathesis polymerization are known, and the repeating unit represented by the formula (1) is prepared by the former polymerization method. Is obtained, and a cycloolefin resin having a repeating unit represented by the formula (2) is obtained by the latter polymerization method.

  The norbornenes can be synthesized by a Diels-Alder reaction between olefins and cyclopentadiene, and various types of norbornenes can be synthesized by changing the substituent of the double bond carbon of the olefins. .

[In the formula (1), m represents an integer of 0 to 3, and R ^{11 to} R ¹⁴ are the same or different and are each a hydrogen atom, a halogen atom, an alkyl group, a cycloalkyl group, an alkenyl group, an alkynyl group, an alkoxy group. , An alkoxyalkyl group, an alkoxycarbonyl group, or an alkoxycarbonylalkyl group. ]

[In the formula (2), n represents an integer of 0 to 3, and R ^{21 to} R ²⁴ are the same or different and each represent a hydrogen atom, a halogen atom, an alkyl group, a cycloalkyl group, an alkenyl group, an alkynyl group, an alkoxy group. , An alkoxyalkyl group, an alkoxycarbonyl group, or an alkoxycarbonylalkyl group. ]

  The cycloolefin-based resin preferably has a norbornane skeleton in the repeating unit. Therefore, in the formulas (1) and (2), m is preferably an integer of 0 to 3, and n is preferably an integer of 1 to 3. If the repeating unit of the cycloolefin-based resin has a norbornane skeleton, the steric hindrance of the cycloolefin-based resin is increased, and the cycloolefin-based resin is hardly crystallized, and the transparency is easily enhanced. Further, by having a norbornane skeleton, the molecular weight increases, the glass transition temperature can be increased, and the heat resistance of the cycloolefin-based resin can be increased. In addition, m is more preferably 0 to 2, more preferably 0 or 1, and n is more preferably 1 or 2, and still more preferably 1, from the viewpoint of easiness of production of norbornenes which are monomer components.

In the formulas (1) and (2), examples of the halogen atoms of R ^{11 to} R ¹⁴ and R ^{21 to} R ²⁴ include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

The alkyl group and the alkoxy group represented by R ^{11 to} R ¹⁴ and R ^{21 to} R ²⁴ preferably have 1 to 10 carbon atoms, more preferably 1 to 6, and still more preferably 1 to 3. Examples of the alkyl group include a methyl group, an ethyl group, an n-propyl group, and an isopropyl group. Examples of the alkoxy group include a methoxy group, an ethoxy group, an n-propoxy group, and an isopropoxy group.

Cycloalkyl groups R ¹¹ to R ¹⁴ and R ²¹ to R ²⁴ is preferably a carbon number of 5-10, 6-8 is more preferable. Examples of the cycloalkyl group include a cyclopentyl group and a cyclohexyl group.

The alkenyl group and alkynyl group of R ^{11 to} R ¹⁴ and R ^{21 to} R ²⁴ preferably have 2 to 10 carbon atoms, more preferably 2 to 6, and even more preferably 2 to 4. Examples of the alkenyl group include an ethenyl group and a 2-propenyl group. Examples of the alkynyl group include an ethynyl group and a 2-propynyl group.

The alkoxycarbonyl group of R ^{11 to} R ¹⁴ and R ^{21 to} R ²⁴ preferably has 2 to 10 carbon atoms, more preferably 2 to 6, and further preferably 2 to 4. Examples of the alkoxycarbonyl group include a methoxycarbonyl group, an ethoxycarbonyl group, a propoxycarbonyl group, an isopropoxycarbonyl group, and the like.

Alkoxyalkyl groups R ¹¹ to R ¹⁴ and R ²¹ to R ²⁴ is preferably a carbon number of 2-10, more preferably 2-7, 2-5 is more preferable. As the alkoxyalkyl group, methoxymethyl group (CH ₃ OCH ₂ -), ethoxymethyl group _{(C 2 H 5 OCH 2 -} ), methoxy ethyl group _{(CH 3 OC 2 H 4 -} ) , and the like.

Alkoxycarbonylalkyl groups R ¹¹ to R ¹⁴ and R ²¹ to R ²⁴ is preferably has 3 to 10 carbon atoms, more preferably 3 to 8, 3 to 6 is more preferred. The alkoxycarbonyl group, methoxycarbonylmethyl group (CH ₃ OCOCH ₂ -), ethoxycarbonylmethyl group _{(C 2 H 5 OCOCH 2 -} ) - and the like is, methoxycarbonyl ethyl group (CH ₃ OCOC ₂ H ₄₎ .

R ^{11 to} R ¹⁴ and R ^{21 to} R ^{24 each} represent a hydrogen atom, an alkyl group, a cycloalkyl group, an alkoxy group or the like in view of the ease of production of a cycloolefin resin (easiness of synthesis of norbornenes and control of polymerization of norbornenes). It is preferably a group, an alkoxyalkyl group, an alkoxycarbonyl group, or an alkoxycarbonylalkyl group. Preferably, two or more of R ^{11 to} R ¹⁴ are hydrogen atoms, and two or more of R ^{21 to} R ²⁴ are hydrogen atoms.

In the formulas (1) and (2), for example, R ^{11 to} R ¹⁴ may be all hydrogen atoms, and R ^{21 to} R ²⁴ may be all hydrogen atoms. In this case, the heat resistance of the infrared absorbing layer can be easily increased, and the moisture resistance and the chemical resistance to acids and alkalis can also be increased.

In the formulas (1) and (2), at least one of R ^{11 to} R ¹⁴ and at least one of R ^{21 to} R ²⁴ represent an alkoxy group, an alkoxyalkyl group, an alkoxycarbonyl group, or an alkoxy group. It may be a carbonylalkyl group. When the cycloolefin-based resin has such a functional group, the cycloolefin-based resin easily interacts with the silane coupling agent having an amino group, and easily enhances the adhesion between the infrared absorbing layer and the glass substrate. In addition, it is preferable that these functional groups are not provided so much from the viewpoint of chemical resistance. Therefore, an alkoxy group, an alkoxyalkyl group, an alkoxycarbonyl group, and an alkoxycarbonyl group may be used as R ^{11 to} R ¹⁴ or R ^{21 to} R ^24. When a polar functional group selected from an alkyl group is included, one of R ^{11 to} R ¹⁴ or one of R ^{21 to} R ²⁴ is preferably the polar functional group.

  The cycloolefin-based resin preferably has a repeating unit represented by the formula (1) or (2) in a proportion of 50% by mass or more, more preferably 70% by mass or more, and preferably 80% by mass or more. More preferred. The cycloolefin-based resin may be substantially composed of only the repeating unit represented by the formula (1) or (2). Further, it may have a plurality of repeating units represented by the formula (1), and may have a plurality of repeating units represented by the formula (2).

  The cycloolefin-based resin may have both the repeating unit represented by the formula (1) and the repeating unit represented by the formula (2). In this case, the cycloolefin-based resin preferably has a repeating unit represented by the formula (1) and a repeating unit represented by the formula (2) in a proportion of 50% by mass or more, and 70% by mass. % Or more, more preferably 80% by mass or more.

  The cycloolefin-based resin may have a repeating unit other than the repeating unit represented by the formula (1) or (2). In this case, the monomer components other than norbornenes include, for example, chain olefins such as ethylene and propylene; methyl (meth) acrylate, ethyl (meth) acrylate, cyclohexyl (meth) acrylate, and cyclohexylmethyl (meth) acrylate. (Meth) acrylic acid esters; vinyl ethers such as methyl vinyl ether, ethyl vinyl ether, 2-ethylhexyl vinyl ether, and cyclohexyl vinyl ether; vinyls such as styrene, α-methylstyrene, and vinyl acetate; hexanediol divinyl ether, trimethylolpropane trivinyl ether And the like. Further, the cycloolefin-based resin has an alicyclic structure such as 2,4-dimethylene-bicyclo [3.3.0] octane other than the alicyclic structure represented by the formula (1) or (2). It may have a repeating unit. Among these, the other repeating unit is preferably a repeating unit composed of a chain or cyclic hydrocarbon, whereby the repeating unit represented by the formula (1) or (2) is added to the cycloolefin resin. It is easy to impart properties derived from

  As the cycloolefin-based resin, commercially available products may be used. For example, TOPAS (registered trademark) manufactured by Polyplastics Corporation, APEL (registered trademark) manufactured by Mitsui Chemicals, ZEONEX (registered trademark) manufactured by Zeon Corporation, and ZEONOR ( (Registered trademark), ARTON (registered trademark) manufactured by JSR Corporation, or the like can be used.

  The content of the cycloolefin-based resin in the infrared absorption layer may be appropriately adjusted in consideration of the adhesion to the glass substrate, the moldability of the cycloolefin-based resin, and the like. % By mass or more, more preferably 85% by mass or more, further preferably 99.5% by mass or less, more preferably 99% by mass or less, and even more preferably 98% by mass or less.

  The phthalocyanine-based compound will be described. A phthalocyanine-based compound has a phthalocyanine skeleton (that is, a structure in which four phthalimides are cross-linked by nitrogen atoms), and is generally known to absorb a wavelength in an infrared region (particularly, a near infrared region). When the phthalocyanine-based compound is contained in the infrared absorbing layer, infrared light can be cut from light transmitted through the infrared absorbing filter. Further, since the phthalocyanine-based compound has a high decomposition temperature, even if the infrared absorption filter is subjected to a high temperature, the infrared absorption ability is not easily damaged.

  In the infrared absorption filter of the present invention, a phthalocyanine compound having less than 8 ester bonds in one molecule or having no ester bond is used as the phthalocyanine compound contained in the infrared absorption layer. By using such a phthalocyanine-based compound, the silane coupling agent having an amino group used as a binder easily acts on the cycloolefin-based resin, and the adhesion (adhesion) between the infrared absorbing layer and the glass substrate is secured. It is thought to be done. In the following, a phthalocyanine-based compound having less than eight ester bonds or having no ester bond in one molecule may be referred to as a “specific phthalocyanine-based compound”.

  The specific phthalocyanine-based compound preferably has no ester bond as much as possible from the viewpoint of increasing the adhesion (adhesion) between the infrared absorbing layer and the glass substrate. Therefore, the specific phthalocyanine-based compound preferably has four or less ester bonds in one molecule or has no ester bond, and preferably has two or less ester bonds in one molecule or has no ester bond. It is more preferred that it has no ester bond.

  The specific phthalocyanine-based compound is preferably a compound represented by the following formula (3).

In the formula (3), M represents a metal atom, a metal oxide or a metal halide, and R ^{1a to} R ^1d , R ^{2a to} R ^2d , R ^{3a to} R ^3d and R ^{4a to} R ^4d are the same or different. Represents a hydrogen atom, a halogen atom, an alkoxy group which may have a substituent, or an aryloxy group which may have a substituent. The metal element constituting M may be bonded to or coordinated with another element such as oxygen or halogen.

  In the formula (3), examples of the metal element constituting M include copper, zinc, indium, cobalt, vanadium, iron, nickel, tin, silver, magnesium, sodium, lithium, lead, and the like. Among these metal elements, copper, vanadium, and zinc are preferred, and copper and zinc are more preferred, from the viewpoint of visible light transmission and light resistance. Copper phthalocyanine (copper complex of phthalocyanine) is less deteriorated by light and has excellent light resistance. Zinc phthalocyanine (a zinc complex of phthalocyanine) is particularly useful for obtaining an infrared absorption filter having high light selective transmission. Both copper phthalocyanine and zinc phthalocyanine are excellent in solubility in cycloolefin-based resins.

In the formula (3), examples of the halogen atom of R ^{1a to} R ^1d , R ^{2a to} R ^2d , R ^{3a to} R ^3d, and R ^{4a to} R ^4d include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. .

The optionally substituted alkoxy group of R ^{1a to} R ^1d , R ^{2a to} R ^2d , R ^{3a to} R ^3d and R ^{4a to} R ^4d preferably has 1 to 10 carbon atoms. To 6 are more preferable, and 1 to 3 are still more preferable. Examples of the alkoxy group include a methoxy group, an ethoxy group, an n-propoxy group, and an isopropoxy group. Examples of the substituent that may be bonded to the alkoxy group include a halogen atom, an aryl group, and an aryloxy group. A substituent having an ester bond (for example, an alkoxycarbonyl group, an alkoxyalkoxycarbonyl group, an alkoxycarbonylalkyl group, an aryloxycarbonyl group, or the like) may be bonded to the alkoxy group. ), The number of ester bonds contained in the compound is less than 8. In addition, the substituent which may be bonded to the alkoxy group preferably has no ester bond.

The aryloxy group which may have a substituent represented by R ^{1a to} R ^1d , R ^{2a to} R ^2d , R ^{3a to} R ^3d and R ^{4a to} R ^4d preferably has 6 to 15 carbon atoms, 6-12 are more preferred, and 6-10 are even more preferred. Examples of the aryloxy group include a phenoxy group and a naphthoxy group. Examples of the substituent that may be bonded to the aryloxy group include a halogen atom, an alkyl group optionally substituted with a halogen atom, an alkoxy group, a nitro group, a cyano group, and the like. A substituent having an ester bond (for example, an alkoxycarbonyl group, an alkoxyalkoxycarbonyl group, an alkoxycarbonylalkyl group, an aryloxycarbonyl group, or the like) may be bonded to the aryloxy group. The number of ester bonds contained in the compound of 3) is set to be less than 8. The substituent that may be bonded to the aryloxy group preferably has no ester bond.

The compound represented by the formula (3) preferably has a halogen atom or an electron donating group bonded to the phthalocyanine skeleton. Accordingly, at least one of R ^{1a to} R ^1d , R ^{2a to} R ^2d , R ^{3a to} R ^3d and R ^{4a to} R ^4d is a halogen atom, an alkoxy group which may have a substituent, or It is preferably an aryloxy group which may have a substituent. In consideration of the actual method of synthesizing the phthalocyanine compound, one or more of R ^{1a to} R ^1d , one or more of R ^{2a to} R ^2d , and one or more of R ^{3a to} R ^3d And at least one of R ^{4a to} R ^4d is preferably a halogen atom, an alkoxy group which may have a substituent, or an aryloxy group which may have a substituent. Since a halogen atom, an alkoxy group, and an aryloxy group are electron donating groups, if these substituents are bonded to the phthalocyanine skeleton, the absorption wavelength of the phthalocyanine-based compound shifts to a longer wavelength side, and in the infrared region. Can increase the absorption capacity. Further, when a substituent is bonded to an alkoxy group or an aryloxy group, if the substituent is electron-donating, it preferably contributes to a long-wavelength shift of the absorption wavelength in the phthalocyanine-based compound, and is preferably electron-withdrawing. A phthalocyanine compound is preferable because it contributes to improving the durability of the phthalocyanine compound.

From the viewpoint of increasing the solubility of the phthalocyanine compound, a halogen atom that can be bonded to the phthalocyanine skeleton, or a halogen atom that can be bonded to an alkoxy group or an aryloxy group that can be bonded to the phthalocyanine skeleton is a fluorine atom or a chlorine atom. Is preferred. In addition, one or more of R ^{1a to} R ^1d , one or more of R ^{2a to} R ^2d , one or more of R ^{3a to} R ^3d , and one or more of R ^{4a to} R ^4d Is preferably an aryloxy group which may have a substituent. From the viewpoint of improving the solubility, the aryloxy group which may have a substituent is preferably bonded to both R ^ka and R ^kd (k is an integer of 1 to 4). . This is because the aryloxy group which may have a substituent is bonded to both R ^ka and R ^kd (k represents an integer of 1 to 4), so that the phthalocyanine molecule is distorted due to a steric effect, and Is to improve. From the viewpoint of improving durability, the aryloxy group which may have a substituent is bonded to one or both of R ^kb and R ^kc (k represents an integer of 1 to 4). Is preferred. This is because the aryloxy group which may have a substituent is bonded to one or both of R ^kb and R ^kc (k represents an integer of 1 to 4), and the planarity of the phthalocyanine molecule is reduced. This is because the association between molecules is further promoted, and the effect of heat and light is less than that of a single molecule.

  The specific phthalocyanine compound preferably has an absorption maximum wavelength in a wavelength range of 600 nm to 900 nm. If the specific phthalocyanine-based compound has an absorption maximum wavelength in such a wavelength range, light (electromagnetic waves) particularly in the range of 600 nm to 1000 nm is easily absorbed, and optical noise due to near infrared rays is reduced or eliminated. It becomes possible. Therefore, it becomes possible to obtain an infrared absorption filter having a high visible light transmittance and an excellent blocking performance of wavelengths in the near infrared region. Further, such an infrared absorption filter is excellent in optical noise reduction performance. For example, when the specific phthalocyanine-based compound represented by the above formula (3) is used, it is easy to have an absorption maximum in such a wavelength range.

  The specific phthalocyanine-based compound more preferably has an absorption maximum wavelength in a wavelength range of 600 nm to 800 nm, and further preferably has an absorption maximum wavelength in a wavelength range of 650 nm to 750 nm. The specific phthalocyanine-based compound preferably does not substantially have an absorption maximum wavelength in a wavelength range of 400 nm or more and less than 600 nm. The specific phthalocyanine-based compound preferably has a maximum absorption peak wavelength in a wavelength range of 600 nm to 900 nm in a wavelength range of 350 nm to 1000 nm. The "maximum absorption wavelength" is the point at which the absorbance changes from increasing to decreasing when the relationship between the wavelength and the absorbance is represented by a two-dimensional graph on the XY plane with the X axis as the wavelength and the Y axis as the absorbance. Means wavelength. Further, the "maximum absorption peak wavelength" means the one having the maximum absorbance among the maximum absorption wavelengths.

  The infrared absorbing layer may contain two or more specific phthalocyanine compounds, or may contain a phthalocyanine compound other than the specific phthalocyanine compound. For example, if the infrared absorbing layer contains two or more phthalocyanine-based compounds having an absorption maximum wavelength in a wavelength range of 600 nm to 900 nm, it is possible to absorb infrared rays in a wide wavelength range. The specific phthalocyanine-based compound preferably accounts for 75% by mole or more of all the phthalocyanine-based compounds contained in the infrared absorbing layer, more preferably 85% by mole or more, even more preferably 95% by mole or more. It is particularly preferable that the absorption layer contains substantially only the specific phthalocyanine compound as the phthalocyanine compound.

  The content of the phthalocyanine-based compound in the infrared-absorbing layer may be appropriately adjusted in consideration of the balance between the ability to absorb infrared light and the transmittance of visible light, adhesion to a glass substrate, moldability of a cycloolefin-based resin, and the like. However, for example, 0.05% by mass or more is preferable, 0.1% by mass or more is more preferable, 0.5% by mass or more is more preferable, 30% by mass or less is preferable, 20% by mass or less is more preferable, % By mass or less is more preferable.

  The phthalocyanine-based compound may be synthesized using a known method, and can generally be obtained by heating a phthalonitrile derivative without a solvent or in the presence of an organic solvent. The synthesis of the phthalocyanine compound can be referred to, for example, Japanese Patent Publication No. 06-031239, Japanese Patent No. 372298, Japanese Patent No. 3226504, Japanese Patent Application Laid-Open No. 2010-077408, and the like.

  The silane coupling agent having an amino group will be described. The silane coupling agent having an amino group can be used without any particular limitation as long as a hydrolyzable group such as an alkoxy group and a substituent having an amino group are bonded to a silicon atom. In the silane coupling agent, a substituent other than an amino group-containing substituent and an alkoxy group may be bonded to a silicon atom. The silane coupling agent having an amino group functions as a binder between the glass substrate and the infrared absorbing layer, binds to the glass substrate by a hydrolyzable group, and interacts with the cycloolefin resin of the infrared absorbing layer by the amino group, It is considered that the adhesion (adhesion) of the infrared absorbing layer to the glass substrate is increased.

  Cycloolefin-based resins containing phthalocyanine-based compounds cannot be sufficiently adhered to a glass substrate simply by coating on a glass substrate, and peel off from the glass substrate especially under severe conditions of high temperature and high humidity. Easier to do. In the present invention, in order to ensure the adhesion between the cycloolefin-based resin (infrared absorbing layer) and the glass substrate, in particular, in order to show sufficient adhesion even under high temperature and high humidity conditions, a silane having an amino group is used. A coupling agent is used. Although it is unknown what kind of interaction the amino group contained in the silane coupling agent enhances the adhesion with the cycloolefin resin, the present inventors have proposed various kinds of silane coupling agents. Investigations have revealed that a silane coupling agent having an amino group is particularly effective for enhancing the adhesion between a cycloolefin-based resin and a glass substrate. For example, not only when using a cycloolefin resin having a polar functional group in the repeating unit, but also when using a cycloolefin resin having only an alicyclic structure without a polar functional group in the repeating unit, It has been found that the use of a silane coupling agent having an amino group can enhance the adhesion to a glass substrate.

  In the silane coupling agent having an amino group, a silicon atom is bonded to a substituent having an amino group and two or three identical or different alkoxy groups (for example, a methoxy group, an ethoxy group, a propoxy group, and an isopropoxy group). It is preferable that they are obtained. If two or three alkoxy groups are bonded to the silicon atom, the silane coupling agent can bond to the glass substrate, and the silane coupling agent can form a siloxane bond between the silicon atoms. It becomes easy to be fixed firmly. Preferably, the silane coupling agent has three alkoxy groups bonded to a silicon atom.

  Preferably, one or two amino group-containing substituents are bonded to the silicon atom, and more preferably, only one is bonded. The substituent having an amino group may have only one amino group or may have two or more amino groups in the substituent. The amino group is preferably a primary amino group or a secondary amino group, and may have both a primary amino group and a secondary amino group. Preferably, the silane coupling agent has at least a primary amino group, whereby the adhesion between the cycloolefin-based resin (infrared absorbing layer) and the glass substrate is easily increased.

  Examples of the silane coupling agent having an amino group include 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-aminopropyltriisopropoxysilane, 3-aminopropylmethyldimethoxysilane, and 3-aminopropylmethyldimethoxysilane. Ethoxysilane, 3- (2-aminoethyl) aminopropyltrimethoxysilane, 3- (2-aminoethyl) aminopropylmethyldimethoxysilane, 3- (2-aminoethyl) aminopropyltriethoxysilane, 3- (2- (Aminoethyl) aminopropylmethyldiethoxysilane, 3- (2-aminoethyl) aminopropyltriisopropoxysilane, 3- (6-aminohexyl) aminopropyltrimethoxysilane, 3-ureidopropyltrimethoxysilane, 3-ureido Propyl triethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, N-benzyl-3-aminopropyltrimethoxysilane, N-vinylbenzyl-3-aminopropyltriethoxysilane, N-cyclohexylaminomethyltriethoxy Silane, N-cyclohexylaminomethyldiethoxymethylsilane, N-phenylaminomethyltrimethoxysilane, (2-aminoethyl) aminomethyltrimethoxysilane, bis (3-trimethoxysilylpropyl) amine, N, N'-bis [3- (trimethoxysilyl) propyl] ethylenediamine and the like. These silane coupling agents may be used alone or in combination of two or more. Examples of the silane coupling agent having an amino group include 3-aminopropyl trialkoxysilane and 3-aminopropyltrialkoxysilane, which can easily secure adhesion between the cycloolefin-based resin (infrared absorbing layer) and the glass substrate and are easily available. It is preferable to use (2-aminoethyl) aminopropyl trialkoxysilane.

  As for the silane coupling agent having an amino group, 3-aminopropyltrimethoxysilane can be obtained as KBM-903 manufactured by Shin-Etsu Silicones, and 3-aminopropyltriethoxysilane can be obtained as Z-6011 manufactured by Dow Corning Toray Co., Ltd. 3- (2-aminoethyl) aminopropyltrimethoxysilane is available as Z-6020 manufactured by Dow Corning Toray.

  The silane coupling agent having an amino group may be mixed with a cycloolefin-based resin, and the structure derived from the silane coupling agent may be present in the infrared absorbing layer. A binder layer different from the infrared absorbing layer may be formed between the infrared absorbing layer and the glass substrate. In the former case, the infrared absorption filter of the present invention has a glass substrate and an infrared absorption layer provided on the glass substrate, and the infrared absorption layer has a cycloolefin resin, a specific phthalocyanine compound, and an amino group. (Hereinafter, referred to as an infrared absorption filter according to the first embodiment). In the latter case, the infrared absorption filter of the present invention has a glass substrate and an infrared absorption layer provided on the glass substrate, and the infrared absorption layer is a resin containing a cycloolefin-based resin and a specific phthalocyanine-based compound. A binder layer formed of a silane coupling agent having an amino group is provided between the infrared absorbing layer and the glass substrate formed of the composition (hereinafter, referred to as an infrared absorbing filter according to the second embodiment). ). In any case, by using a silane coupling agent having an amino group, the infrared absorbing layer is less likely to be separated from the glass substrate, and the adhesion of the infrared absorbing layer to the glass substrate can be increased. Therefore, the infrared absorption filter of the present invention has excellent heat resistance and weather resistance, and the infrared absorption filter can be mounted on an electronic component by solder reflow. In addition, the infrared absorbing layer is less likely to be peeled off even in a hot summer environment or a high humidity environment.

  In the infrared absorption filter according to the first embodiment, the infrared absorption layer has a resin composition containing a cycloolefin-based resin, a specific phthalocyanine-based compound, and a silane coupling agent having an amino group (hereinafter, referred to as a “resin composition”). A "). The resin composition A contains a cycloolefin-based resin, a specific phthalocyanine-based compound, and a silane coupling agent having an amino group, and is suitably used for forming an infrared absorption layer on a glass substrate. That is, the resin composition A is for forming an infrared absorbing layer on a glass substrate, and a cycloolefin-based resin and a phthalocyanine-based compound having less than 8 ester bonds or having no ester bond in one molecule, And a silane coupling agent having an amino group.

  In the resin composition A, the cycloolefin resin is preferably dissolved in an organic solvent. That is, the resin composition A preferably contains an organic solvent. In this case, since the resin composition A can be formed on a glass substrate by a solvent casting method, a spin coating method, or the like, a resin layer can be formed on the glass substrate at a relatively low temperature, and It becomes easy to form the infrared absorption layer uniformly on the glass substrate. Further, the infrared absorbing layer can be made thinner, and a smaller optical device or the like can be obtained.

  As the organic solvent, aromatic hydrocarbons such as benzene, toluene and xylene; aliphatic hydrocarbons such as pentane, hexane, cyclohexane and heptane; chloroform, methylene chloride and dichloroethane in view of solubility of the cycloolefin resin; , Halogenated hydrocarbons such as chlorobenzene and dichlorobenzene are preferably used.

  When the resin composition A contains an organic solvent, the cycloolefin-based resin is preferably contained in an amount of 1 part by mass or more, more preferably 3 parts by mass or more, still more preferably 5 parts by mass or more, based on 100 parts by mass of the organic solvent. Also, it is preferably 30 parts by mass or less, more preferably 20 parts by mass or less, and even more preferably 15 parts by mass or less. By adjusting the concentration of the cycloolefin-based resin in this manner, the cycloolefin-based resin is easily dissolved uniformly in an organic solvent, and a film is easily formed on a glass substrate by a solvent casting method, a spin coating method, or the like.

  In the resin composition A, the phthalocyanine-based compound is preferably contained in an amount of 0.1 part by mass or more, more preferably 0.5 part by mass or more, and still more preferably 1 part by mass or more, based on 100 parts by mass of the cycloolefin-based resin. It is preferably 30 parts by mass or less, more preferably 20 parts by mass or less, and even more preferably 10 parts by mass or less. The silane coupling agent having an amino group is preferably contained in the resin composition A in an amount of 0.5 parts by mass or more, more preferably 1 part by mass or more, and 8 parts by mass with respect to 100 parts by mass of the cycloolefin-based resin. Or less, more preferably 5 parts by mass or less. By adjusting the content of each component as described above, it becomes easy to form an infrared absorbing layer having excellent adhesion to a glass substrate.

  Examples of the method for applying the resin composition A containing a solvent include spin coating, solvent casting, roll coating, spray coating, bar coating, dip coating, screen printing, flexographic printing, and inkjet printing. It is preferably used. Among them, the spin coating method is preferably used because an infrared absorbing layer having a thin and uniform thickness is easily obtained. In the spin coating method, for example, after the resin composition A is placed on a glass substrate, the resin composition A is rotated at a rotation speed of 500 rpm to 4000 rpm for about 10 seconds to 60 seconds at around room temperature (25 ° C.) so that the resin composition A becomes thin on the glass substrate. Thus, a coating film having a uniform thickness can be formed. Thereafter, by performing a heat treatment, the solvent is removed and the cycloolefin-based resin is cured or dried, and the cycloolefin-based resin, the specific phthalocyanine-based compound, and the silane coupling agent having an amino group are formed on a glass substrate. An infrared absorbing layer containing the same can be formed. At this time, it is considered that the silane coupling agent having an amino group binds to the glass substrate and interacts with the cycloolefin resin, whereby the infrared absorbing layer is fixed to the glass substrate. The heat treatment is preferably performed at 80 ° C to 250 ° C (preferably 100 ° C to 220 ° C) for 5 minutes to 60 minutes. The heat treatment may be performed in two stages by changing the temperature conditions. For example, it is preferable that the second heat treatment be performed at a higher temperature than the first heat treatment. Further, it is preferable to perform the treatment under a nitrogen atmosphere.

  In the infrared absorption filter according to the second embodiment, the infrared absorption layer is formed from a resin composition containing a cycloolefin-based resin and a specific phthalocyanine-based compound (hereinafter, referred to as “resin composition B”). Then, a binder layer formed from a silane coupling agent having an amino group is provided between the infrared absorbing layer and the glass substrate.

  Although the binder layer is formed from a silane coupling agent having an amino group, the binder layer is formed of a silane coupling agent having an amino group and a solvent in order to form the binder layer on the glass substrate as uniformly as possible. And is preferably formed from a binder composition containing At this time, it is preferable to use water and / or an alcohol (for example, methanol, ethanol, propanol, etc.) as the solvent from the viewpoint of promoting the hydrolysis of the silane coupling agent and strengthening the bond with the glass substrate. By using water and / or an alcohol as a solvent, the alkoxy group of the silane coupling agent is hydrolyzed to generate a silanol group, and the silanol group is dehydrated and condensed with a hydroxyl group on the surface of the glass substrate to form a dehydration condensate. Can be firmly bonded. As a result, the adhesion between the glass substrate and the binder layer can be improved.

  The content of the solvent in the composition for a binder is preferably 92% by mass or more, more preferably 95% by mass or more, still more preferably 98% by mass or more, and 99.9% by mass or less in 100% by mass of the composition for a binder. Is preferable, and 99.5 mass% or less is more preferable. Further, the content of the silane coupling agent having an amino group in the binder composition is preferably 0.05% by mass or more, more preferably 0.1% by mass or more, based on 100% by mass of the binder composition. 0.2 mass% or more is more preferable, 5 mass% or less is preferable, and 3 mass% or less is more preferable.

  Preferably, the composition for a binder contains a hydrolysis catalyst. When the hydrolysis catalyst is contained in the composition for a binder, the hydrolysis reaction of the alkoxy group of the silane coupling agent is promoted. As the hydrolysis catalyst, bases such as ammonia, urea, ethanolamine and tetramethylammonium hydroxide; inorganic acids such as sulfuric acid, phosphoric acid, nitric acid and hydrochloric acid; formic acid, acetic acid, propionic acid, butyric acid, oxalic acid, fumaric acid, Organic acids such as maleic acid and sulfonic acid are exemplified. Among these, it is preferable to use an organic acid.

  The content of the catalyst in the binder composition is preferably 0.0001% by mass or more, more preferably 0.01% by mass or more, and further preferably 3% by mass or less, preferably 1% by mass, in 100% by mass of the binder composition. The following is more preferred.

  The binder layer is preferably formed on a glass substrate by applying a composition for a binder on a glass substrate and then performing a heat treatment. As a result, the solvent contained in the binder composition is volatilized, and the silanol group generated by hydrolysis of the alkoxy group of the silane coupling agent is dehydrated and condensed with the hydroxyl group on the surface of the glass substrate to form a bond. The binder layer is firmly fixed thereon.

  As a coating method of the composition for the binder, a spin coating method, a solvent casting method, a roll coating method, a spray coating method, a bar coating method, a dip coating method, a screen printing method, a flexographic printing method, an inkjet method, etc. are preferably used. Can be Among them, the spin coating method is preferably used because it is easy to obtain a binder layer having a thin and uniform thickness. In the spin coating method, for example, after a composition for a binder is placed on a glass substrate, the composition is rotated on a glass substrate at a rotation speed of about 500 rpm to 4000 rpm for about 10 seconds to 60 seconds at around room temperature (25 ° C.), so that a thin layer is formed on the glass substrate. Thus, a coating film having a uniform thickness can be formed. Thereafter, a heat treatment is performed at, for example, 60 ° C. to 150 ° C. (preferably 80 ° C. to 120 ° C.) for 5 minutes to 30 minutes, so that the silane coupling agent having an amino group is fixed on the glass substrate. A binder layer can be formed thereon.

  Resin composition B can be prepared in the same manner as resin composition A, except that it does not contain a silane coupling agent having an amino group. The resin composition B contains a cycloolefin-based resin and a specific phthalocyanine-based compound, and forms an infrared absorption layer on a glass substrate via a binder layer formed from a silane coupling agent having an amino group. It is preferably used. That is, the resin composition B is for forming an infrared absorbing layer on a binder layer formed from a silane coupling agent having an amino group, and has less than eight ester bonds in one molecule with a cycloolefin resin. Or a phthalocyanine compound having no ester bond.

  It is preferable that the resin composition B also contains an organic solvent, and it is preferable that the resin composition B is coated on the binder layer and heated as in the case of the resin composition A. Thereby, the infrared absorption layer is formed on the binder layer, and the amino group contained in the binder layer interacts with the cycloolefin resin of the infrared absorption layer, so that the infrared absorption layer is formed on the glass substrate via the binder layer. And the adhesion between the infrared absorbing layer and the glass substrate is enhanced.

  The infrared absorbing layer may appropriately contain additives in addition to the cycloolefin-based resin, the specific phthalocyanine-based compound, and the silane coupling agent having an amino group according to the purpose. Additives include curing agents, leveling agents, pigments, pigment dispersants, ultraviolet absorbers, antioxidants, viscosity modifiers, light stabilizers, metal deactivators, peroxide decomposers, fillers, and reinforcements Materials, plasticizers, lubricants, anticorrosives, rust inhibitors, emulsifiers, mold release agents, fluorescent brighteners, organic flame retardants, inorganic flame retardants, dripping inhibitors, melt flow modifiers, electrostatics Inhibitors, slippers, adhesion promoters, antifouling agents, surfactants, defoamers, polymerization inhibitors, photosensitizers, surface improvers, adhesion improvers, heat stabilizers, antibacterial and antifungal agents Agents, flame retardants and the like.

  The infrared absorbing layer may contain any organic or inorganic fine particles. The organic fine particles or the inorganic fine particles are used, for example, for imparting a function relating to a refractive index, conductivity, or the like to the infrared absorbing layer. Specific examples of fine particles useful for increasing the refractive index of the infrared absorbing layer and imparting conductivity include zinc oxide, titanium oxide, zirconium oxide, aluminum oxide, tin oxide, tin-doped indium oxide, antimony-doped tin oxide, indium-doped zinc oxide, Examples include indium oxide and antimony oxide. On the other hand, specific examples of fine particles useful for lowering the refractive index of the infrared absorption layer include magnesium fluoride, silica, hollow silica, and the like. Specific examples of fine particles useful for imparting anti-glare properties include, in addition to the above fine particles, inorganic fine particles such as calcium carbonate, barium sulfate, talc, and kaolin: silicone resins, melamine resins, benzogamine resins, acrylic resins, polystyrene resins, and the like. And organic fine particles such as a copolymerized resin. The infrared absorbing layer may contain only one type of these fine particles, or may contain two or more types of these fine particles.

  The infrared absorbing layer may be provided on only one side of the glass substrate, or may be provided on both sides. The thickness of the infrared absorbing layer may be appropriately set according to the purpose of use and the use environment of the infrared absorbing filter, but from the viewpoint of securing desired infrared cut performance and realizing a thinner, for example, 0.5 μm or more Is preferably 1 μm or more, more preferably 100 μm or less, more preferably 50 μm or less, and still more preferably 10 μm or less.

  The infrared absorbing filter of the present invention may have other layers in addition to the above-described glass substrate, infrared absorbing layer, and binder layer. Note that another layer is not provided between the glass substrate and the infrared absorption layer. Examples of the other layer include a layer having an antireflection property and an antiglare property for reducing reflection of a fluorescent lamp or the like on the outside air side, a layer having an anti-scratch property, a transparent substrate having other functions, and the like.

  It is preferable that the infrared absorption filter has an infrared reflection film (particularly, a near infrared reflection film) provided on the infrared absorption layer. For example, the infrared reflection film is preferably provided on a surface of the infrared absorption layer opposite to the glass substrate. The infrared reflection film is a film having the ability to reflect infrared light. As the infrared reflection film, an aluminum deposition film, a noble metal thin film, a resin film in which metal oxide fine particles containing indium oxide as a main component and containing a small amount of tin oxide are dispersed, a high refractive index material layer and a low refractive index material layer, A dielectric multilayer film or the like stacked alternately can be used. If an infrared reflection film is provided on the infrared absorption filter, infrared light can be further cut off from the transmitted light of the infrared absorption filter. In addition, the infrared reflective film may include the ultraviolet reflective function at the same time (the same film).

  Among the infrared reflective films, 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 the 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 usually 1.7 to 2.5 is 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 the above; mixtures of the above oxides and the above nitrides; and those obtained by doping them with a metal such as aluminum or copper or carbon (eg, tin-doped indium oxide (ITO), antimony-doped tin oxide (ATO)) and the like. No. 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 usually 1.2 to 1.6 is selected. Examples of a material constituting the low refractive index material layer include silicon dioxide (silica), alumina, lanthanum fluoride, magnesium fluoride, and sodium aluminum hexafluoride.

  The infrared absorption filter of the present invention has excellent adhesion between the infrared absorption layer and the glass substrate, and exhibits sufficient adhesion even under high-temperature and high-humidity conditions, and thus has excellent weather resistance. For this reason, for example, it is used as a light selective transmission filter for blocking optical noise in a camera module (solid-state imaging device) application and correcting visibility, and is also mounted on glass or the like of automobiles and buildings exposed to various environments. It can also be used as a heat ray cut filter.

  The infrared absorption filter of the present invention is particularly suitable for use in an imaging device. The present invention also includes an imaging device having an infrared absorption filter. The imaging device is also called a solid-state imaging device or an image sensor chip, and is an electronic component that converts light of a subject into an electric signal and outputs the electric signal. The imaging device usually has a detection device (sensor) such as a charge coupled device (CCD) or a complementary metal-oxide semiconductor (CMOS), and may have a lens. The imaging device is used for, for example, a camera for a mobile phone, a digital camera, a camera for a vehicle, a monitoring camera, a display device (eg, an LED), and the like. The imaging device includes one or more infrared absorption filters of the present invention, and may further include other members as necessary.

  Hereinafter, the present invention will be described in more detail by way of examples, but the scope of the present invention is not limited thereto.

(1) Synthesis of phthalocyanine-based compound (1-1) Synthesis Example 1 (Synthesis of phthalocyanine A)
In a 100 ml four-necked flask, 12.73 g (26.2 mmol) of 3,6-difluoro-4,5-bis (2,5-dichlorophenoxy) phthalonitrile, 0.64 g (7.9 mmol) of zinc oxide, p -0.095 g (0.6 mmol) of toluenesulfonic acid and 50 ml of benzonitrile were charged and maintained at reflux temperature for about 5 hours with stirring. Thereafter, the cooled reaction solution was poured into 500 ml of isopropyl alcohol, and the obtained solid was filtered and washed with 200 ml of isopropyl alcohol to obtain 1.36 g of phthalocyanine A (yield 10.3%). The reaction of phthalocyanine A is shown below in a simplified manner. Phthalocyanine A had an absorption maximum at 667 nm, and the wavelength at which the absorbance was greatest (the maximum absorption peak wavelength) was 667 nm.

(1-2) Synthesis Example 2 (Synthesis of Phthalocyanine B)
In a 1000 ml three-necked flask, 100 g (0.58 mol) of 3-nitrophthalonitrile, 159.7 g (1.16 mol) of potassium carbonate, 104.6 g (0.64 mol) of 2,6-dichlorophenol, and 400 g of acetonitrile were charged. It is. After stirring and reacting at 60 ° C. overnight, the reaction solution was filtered, acetonitrile was distilled off from the filtrate by a rotary evaporator, and methanol was added to perform recrystallization. The obtained crystals were filtered and dried under vacuum to obtain 100.9 g (yield 60.4%) of Intermediate B.

Next, 60.0 g (0.21 mol) of the intermediate B, 5.65 g (0.057 mol) of copper chloride (I), and 140.0 g of diethylene glycol monomethyl ether were charged into a 300 ml four-necked flask, and stirred at 160 ° C. After reacting for 24 hours, 100.0 g of methyl cellosolve was added to prepare a reaction solution. The reaction solution was added dropwise to a mixed solution of methanol and water to precipitate crystals, and after suction filtration, a wet cake was obtained. The obtained cake is again washed with stirring with a mixed solution of methanol and water, filtered by suction, and then dried at 90 ° C. for 24 hours using a vacuum drier to obtain 51.48 g of phthalocyanine B (yield 81. 3%). The reaction of phthalocyanine B from intermediate B is shown below in a simplified manner. In the following, a 2,5-dichlorophenoxy group is bonded to one of R ^ka and R ^kd (k is an integer of 1 to 4). And a hydrogen atom is bonded to the other. Phthalocyanine B had absorption maxima at 630 nm and 701 nm, and the wavelength at which the absorbance was greatest (maximum absorption peak wavelength) was 701 nm.

(1-3) Synthesis Example 3 (Synthesis of phthalocyanine C)
In a 50 ml three-necked flask, 10 g (0.017 mol) of 4,5-bis (2,5-dichlorophenoxy) -3-dimethylphenoxy-6-fluorophthalonitrile and 1.49 g of zinc (II) iodide (0 0.047 mol) and 20 g of benzonitrile, and the mixture was heated to 165 ° C. while stirring under a nitrogen stream, and reacted at the same temperature for about 16 hours. Thereafter, benzonitrile was distilled off, and the mixture was poured into 100 g of methanol, stirred for 1 hour, washed, suction-filtered, and dried in vacuum at 60 ° C. to obtain 8.01 g of phthalocyanine C (yield: 77.8%). Was. The synthesis reaction of phthalocyanine C is shown below in a simplified manner. In the following, a 2,5-dimethylphenoxy group is bonded to one of R ^ka and R ^kd (k is an integer of 1 to 4), and Has a fluorine atom bonded thereto. Phthalocyanine C had absorption maxima at 644 nm and 717 nm, and the wavelength at which the absorbance was greatest (maximum absorption peak wavelength) was 717 nm.

(1-4) Synthesis example 4 (Synthesis of phthalocyanine D)
In a 1000 ml four-neck separable flask were charged 54 g (0.27 mol) of tetrafluorophthalonitrile, 34.5 g (0.59 mol) of potassium fluoride, and 126 g of acetone, and 3-chloro-4-hydroxybenzoate was added to the dropping funnel. 127 g (0.55 mol) of acid methoxyethyl ester and 216 g of acetone were charged. While stirring the reaction vessel under ice-cooling, a solution of 3-chloro-4-hydroxybenzoic acid methoxyethyl ester was added dropwise from the dropping funnel over about 2 hours, and the stirring was further continued for 2 hours. Thereafter, the mixture was stirred overnight while slowly raising the reaction temperature to room temperature. The reaction solution was filtered, acetone was distilled off from the filtrate with a rotary evaporator, and methanol was added to perform recrystallization. The obtained crystals were filtered and dried under vacuum to obtain 108.7 g of Intermediate D (yield: 64.8%).

  Next, 20.0 g (0.032 mol) of the intermediate D, 2.57 g (0.0081 mol) of zinc (II) iodide, and 30.0 g of benzonitrile were charged into a 200 ml four-necked flask, and stirred at 160 ° C. After reacting for 24 hours, 52.7 g of methyl cellosolve was added to prepare a reaction solution. The reaction solution was added dropwise to a mixed solution of methanol and water to precipitate crystals, and after suction filtration, a wet cake was obtained. The obtained cake is again washed with stirring with a mixed solution of methanol and water, suction-filtered, and then dried at 90 ° C. for 24 hours using a vacuum drier to obtain 17.78 g of phthalocyanine D (yield 86. 7%). The reaction of phthalocyanine D from intermediate D is shown below in a simplified manner. Phthalocyanine D had an absorption maximum at 667 nm, and the wavelength at which the absorbance was greatest (maximum absorption peak wavelength) was 667 nm.

(2) Production of infrared absorption filter (2-1) Production example 1
5 parts by mass of phthalocyanine A (phthalocyanine having no ester bond) and 3-aminopropyl were added to a mixture of 100 parts by mass of ARTON (registered trademark) resin, a cycloolefin resin, and 900 parts by mass of o-dichlorobenzene. 3 parts by mass of trimethoxysilane (KBM903 manufactured by Shin-Etsu Silicone Co., Ltd.) was dissolved to obtain a resin composition. After filtering the resin composition to remove insolubles and the like, 0.6 ml was placed on a glass substrate (D263Teco, 60 mm × 60 mm × 0.3 mm, manufactured by SCHOTT) and a spin coater (1H-D7, manufactured by Mikasa Corporation). , The rotation speed was increased to 1000 rpm for 0.2 seconds, the rotation speed was maintained for 10 seconds, then the rotation was stopped for 0.2 seconds, and the resin composition was formed on the glass substrate. . This was heated at 100 ° C. for 3 minutes using a precision thermostat (DH611 manufactured by Yamato Scientific Co., Ltd.), and then heated at 200 ° C. for 30 minutes to obtain an infrared absorption filter having an infrared absorption layer formed on a glass substrate. Got. The thickness of the infrared absorbing layer of the obtained infrared absorbing filter was 1 μm. The thickness of the infrared absorption layer was determined by measuring the thickness of the infrared absorption filter and the thickness of the glass substrate using a micrometer, and determining the difference between the two.

(2-2) Production Example 2
A mixed solution consisting of 1.52 parts by mass of 3-aminopropyltrimethoxysilane (KBM-903 manufactured by Shin-Etsu Silicone Co., Ltd.), 2 parts by mass of ethanol, 0.455 parts by mass of water, and 0.26 parts by mass of formic acid is diluted 100 times with ethanol. Was diluted (1 part by mass of the mixed solution was mixed with 99 parts by mass of ethanol) to prepare a composition P for a binder. 1 ml of the composition P for a binder was placed on a glass substrate (D263Teco, manufactured by SCHOTT, 60 mm × 60 mm × 0.3 mm), and the rotation speed was set to 2200 rpm for 3 seconds using a spin coater (1H-D7 manufactured by Mikasa Corporation). After that, the number of revolutions was maintained for 20 seconds, and then the rotation was stopped over 3 seconds to form a binder composition on a glass substrate. This was dried at 100 ° C. for 10 minutes using a precision thermostat (DH611 manufactured by Yamato Scientific Co., Ltd.), and a binder layer was formed on a glass substrate to obtain a binder-layer-formed glass substrate.

  Dissolve 5 parts by mass of phthalocyanine A (phthalocyanine having no ester bond) in a mixture of 100 parts by mass of ARTON (registered trademark) resin manufactured by JSR, which is a cycloolefin resin, and 900 parts by mass of o-dichlorobenzene. A resin composition was obtained. After filtering the resin composition to remove insolubles and the like, 0.6 ml of the resin composition was placed on a glass substrate on which a binder layer had been formed (on the binder layer), and the resin composition was dried with a spin coater (1H-D7 manufactured by Mikasa Corporation). After increasing the rotation speed to 1000 rpm for 2 seconds, the rotation speed was maintained for 10 seconds, and then stopped for 0.2 seconds, and the resin composition was formed on the glass substrate on which the binder layer was formed. This was heated at 100 ° C. for 3 minutes using a precision thermostat (DH611 manufactured by Yamato Scientific Co., Ltd.), and then heated at 200 ° C. for 30 minutes, whereby an infrared absorbing layer was formed on the binder-layer-formed glass substrate. An infrared absorption filter was obtained. The thickness of the infrared absorbing layer of the obtained infrared absorbing filter was 1 μm. The thickness of the infrared absorption layer was determined by measuring the thickness of the infrared absorption filter and the thickness of the glass substrate on which the binder layer was formed using a micrometer, and determining the difference between the two.

(2-3) Production Example 3
An infrared absorbing filter was produced in the same manner as in Production Example 1, except that phthalocyanine B (phthalocyanine having no ester bond) was used instead of phthalocyanine A.

(2-4) Production example 4
An infrared absorbing filter was produced in the same manner as in Production Example 2, except that phthalocyanine B (phthalocyanine having no ester bond) was used instead of phthalocyanine A.

(2-5) Production example 5
An infrared absorbing filter was produced in the same manner as in Production Example 1, except that phthalocyanine C (phthalocyanine having no ester bond) was used instead of phthalocyanine A.

(2-6) Production example 6
Instead of phthalocyanine A, phthalocyanine C (phthalocyanine having no ester bond) was used, and instead of the binder composition P, 3- (2-aminoethyl) aminopropyltrimethoxysilane (Z-6020 manufactured by Dow Corning Toray Co., Ltd.) ) A mixture of 1.88 parts by mass, 2 parts by mass of ethanol, 0.455 parts by mass of water and 0.26 parts by mass of formic acid was diluted 100 times with ethanol (99 parts by mass of ethanol was mixed with 1 part by mass of the mixture) )), Except that the composition Q for a binder obtained was used, to produce an infrared absorbing filter in the same manner as in Production Example 2.

(2-7) Production example 7
Infrared absorbing filter in the same manner as in Production Example 1, except that phthalocyanine B was used instead of phthalocyanine A, and 3-aminopropyltriethoxysilane (Z-6011 manufactured by Dow Corning Toray Co., Ltd.) was used as a silane coupling agent. Was prepared.

(2-8) Production Example 8
Production Example 1 was repeated except that phthalocyanine B was used in place of phthalocyanine A and 3- (2-aminoethyl) aminopropyltrimethoxysilane (Z-6020 manufactured by Dow Corning Toray) was used as a silane coupling agent. Similarly, an infrared absorption filter was produced.

(2-9) Production Example 9
Except that phthalocyanine B was used instead of phthalocyanine A, and binder composition Q (a binder composition containing 3- (2-aminoethyl) aminopropyltrimethoxysilane) was used instead of binder composition P. In the same manner as in Production Example 2, an infrared absorption filter was produced.

(2-10) Production Example 10
An infrared absorbing filter was produced in the same manner as in Production Example 1 except that APEL (registered trademark) made by Mitsui Chemicals, Inc. was used instead of ARTON (registered trademark) resin made by JSR as a cycloolefin resin.

(2-11) Production Example 11
An infrared absorbing filter was produced in the same manner as in Production Example 2, except that APEL (registered trademark) made by Mitsui Chemicals, Inc. was used instead of ARTON (registered trademark) resin made by JSR as a cycloolefin-based resin.

(2-12) Production Example 12
As a cycloolefin-based resin, APSR (registered trademark) manufactured by Mitsui Chemicals, Inc. was used in place of ARTON (registered trademark) resin manufactured by JSR, and 3- (3-aminopropyltrimethoxysilane was used instead of 3-aminopropyltrimethoxysilane as a silane coupling agent. An infrared-absorbing filter was produced in the same manner as in Production Example 1, except that 2-aminoethyl) aminopropyltrimethoxysilane (Z-6020 manufactured by Dow Corning Toray) was used.

(2-13) Production Example 13
An infrared absorbing filter was produced in the same manner as in Production Example 1, except that phthalocyanine B was used instead of phthalocyanine A, and no silane coupling agent was used.

(2-14) Production Example 14
An infrared absorbing filter was produced in the same manner as in Production Example 1, except that phthalocyanine D (a phthalocyanine having eight ester bonds) was used instead of phthalocyanine A.

(2-15) Production Example 15
An infrared absorbing filter was produced in the same manner as in Production Example 2, except that phthalocyanine D (phthalocyanine having eight ester bonds) was used instead of phthalocyanine A.

(2-16) Preparation Example 16
Phthalocyanine B is used in place of Phthalocyanine A, and 3-glycidoxypropyltrimethoxysilane which is an epoxysilane instead of 3-aminopropyltrimethoxysilane (Z-6040 manufactured by Dow Corning Toray) as a silane coupling agent. An infrared absorbing filter was produced in the same manner as in Production Example 1 except that was used. 3-glycidoxypropyltrimethoxysilane is a silane coupling agent having no amino group.

(2-17) Production Example 17
Phthalocyanine B was used in place of Phthalocyanine A, and 2 parts by mass of 3-glycidoxypropyltrimethoxysilane (Z-6040 manufactured by Dow Corning Toray Co., Ltd.) as an epoxy silane and 2 parts by mass of ethanol were used instead of the composition P for the binder. Composition obtained by diluting a mixed solution consisting of 1 part by mass of water, 0.455 parts by mass of water and 0.26 parts by mass of formic acid 100-fold with ethanol (99 parts by mass of ethanol is mixed with 1 part by mass of the mixed solution) Except for using R, an infrared absorbing filter was produced in the same manner as in Production Example 2. 3-glycidoxypropyltrimethoxysilane is a silane coupling agent having no amino group.

(2-18) Production Example 18
Production Example 1 was repeated except that phthalocyanine D was used in place of phthalocyanine A and that APEL (registered trademark) made by Mitsui Chemicals was used instead of ARTON (registered trademark) resin made by JSR as a cycloolefin resin. To produce an infrared absorption filter.

(2-19) Production Example 19
Production Example 2 was repeated except that phthalocyanine D was used in place of phthalocyanine A, instead of ARTON (registered trademark) resin manufactured by JSR and APEL (registered trademark) resin manufactured by Mitsui Chemicals, Inc. To produce an infrared absorption filter.

(2-20) Production Example 20
As a cycloolefin-based resin, APSR (registered trademark) manufactured by Mitsui Chemicals, Inc. is used instead of ARTON (registered trademark) resin manufactured by JSR, and epoxysilane is used as a silane coupling agent instead of 3-aminopropyltrimethoxysilane. An infrared absorption filter was produced in the same manner as in Production Example 1, except that certain 3-glycidoxypropyltrimethoxysilane (Z-6040 manufactured by Dow Corning Toray) was used.

(2-21) Production Example 21
As a cycloolefin-based resin, APEL (registered trademark) resin manufactured by Mitsui Chemicals, Inc. is used instead of ARTON (registered trademark) resin manufactured by JSR Corporation, and a composition R (3-glycidoxy) for binder is used instead of the composition P for binder. Infrared absorbing filter was produced in the same manner as in Production Example 2 except that a binder composition containing propyltrimethoxysilane was used.

The ARTON (registered trademark) resin is a cycloolefin resin having a repeating unit represented by the following formula (4), and the APEL (registered trademark) resin is a cycloolefin resin having a repeating unit represented by the following formula (5). estimates that a cycloolefin-based resin having a repeating unit of - [-CH ₂ -CH _2].

(3) Evaluation method by PCT (Pressure Cooker Test) test Regarding the infrared absorption filter produced above, a cut was made in the infrared absorption layer (resin layer) with a cutter (A-300 manufactured by NTT Co., Ltd.), and 2 mm each in a column and a row. By providing 10 cross-cut lines at intervals, 81 squares of 4 mm ² were produced, and an evaluation sample was produced. Next, this evaluation sample was placed in a high-pressure, high-temperature, high-humidity tank (manufactured by Hirayama Seisakusho Co., Ltd., Personal Pressure Cooker PC-242HS-E, operation mode 1) at 120 ° C., 2 atm, and 100% humidity for 15 hours or 50 hours. I put it. Subsequently, at room temperature, a tape (3M (3M) Scotch (registered trademark) transparent pressure-sensitive adhesive tape, transparent and beautiful color (registered trademark)) was stuck so as not to allow air to enter, and left for 5 seconds. Thereafter, the tape was peeled off from the evaluation sample within 1 second, and evaluated according to the following criteria. In addition, the tape was peeled so that the peeling force was constant in all the cells.
：: No peeling occurred in any of the 81 squares produced. Δ: Peeling occurred in 1 to 9 squares of the fabricated 81 squares. ×: Among the squares of the 81 fabricated squares. , 10 to 81 squares peeled off

(4) Results Tables 1 and 2 show the production conditions and PCT test results of the infrared absorption filters of Production Examples 1 to 21. In Tables 1 and 2, phthalocyanines A to C have no ester bond, and phthalocyanine D has eight ester bonds in one molecule. Aminosilanes 1 to 3 are silane coupling agents having an amino group, and epoxysilane is a silane coupling agent having no amino group.

  In Production Examples 1 to 12, since phthalocyanine A to C having no ester bond were used as the phthalocyanine-based compound and a silane coupling agent having an amino group was used, the infrared absorbing layer was used both before and after the PCT test. Peeling was hardly observed, and it was confirmed that the infrared absorbing layer was sufficiently adhered to the glass substrate even under high temperature and high humidity conditions. On the other hand, in Preparation Example 13 in which no silane coupling agent was used and in Preparation Examples 16, 17, 20, and 21 in which a silane coupling agent having an epoxy group without an amino group was used as the silane coupling agent, the PCT test was not performed. Although some of the adhesiveness of the infrared absorbing layer to the glass substrate was recognized, the adhesiveness was significantly reduced after the PCT test. In Preparation Examples 14, 15, 18, and 19 using phthalocyanine D having eight ester bonds in one molecule, the adhesiveness of the infrared absorbing layer to the glass substrate was insufficient before and after the PCT test. there were. In each of the production examples, the maximum peak wavelength of the infrared absorption filter coincided with the maximum peak wavelength of the contained phthalocyanine compound.

  The infrared absorption filter of the present invention can be used in various fields such as an optical device such as a display device or an imaging device. For example, it can be used for electronic parts such as a mobile phone camera, a digital camera, a vehicle-mounted camera, a surveillance camera, and a display element (eg, an LED).

Claims (8)

A glass substrate, an infrared absorption filter having an infrared absorption layer provided on the glass substrate,
The infrared-absorbing layer comprises a cycloolefin resin is represented by the following formula (3), it is formed and no phthalocyanine compound an ester bond, a resin composition containing a silane coupling agent having an amino group An infrared absorption filter characterized by the following.
[In the formula (3), M represents a metal atom, a metal oxide or a metal halide, and R ^{1a to} R ^1d , R ^{2a to} R ^2d , R ^{3a to} R ^3d and R ^{4a to} R ^4d are the same or different. Differently, it represents a hydrogen atom, a halogen atom, an optionally substituted alkoxy group, or an optionally substituted aryloxy group. ] A glass substrate, an infrared absorption filter having an infrared absorption layer provided on the glass substrate,
The infrared-absorbing layer comprises a cycloolefin resin is represented by the following formula (3), formed from a resin composition comprising a no phthalocyanine compound an ester bond,
An infrared absorption filter, wherein a binder layer formed of a silane coupling agent having an amino group is provided between the infrared absorption layer and the glass substrate.
[In the formula (3), M represents a metal atom, a metal oxide or a metal halide, and R ^{1a to} R ^1d , R ^{2a to} R ^2d , R ^{3a to} R ^3d and R ^{4a to} R ^4d are the same or different. Differently, it represents a hydrogen atom, a halogen atom, an optionally substituted alkoxy group, or an optionally substituted aryloxy group. ]   The infrared absorbing filter according to claim 2, wherein the binder layer is formed of a binder composition having a silane coupling agent having an amino group and a hydrolysis catalyst. The infrared absorption filter according to any one of claims 1 to 3 , wherein the phthalocyanine-based compound has an absorption maximum wavelength in a wavelength range of 600 nm to 900 nm. The infrared absorption filter according to any one of claims 1 to 4 , wherein the cycloolefin-based resin has a repeating unit represented by the following formula (1) or (2).
[In the formula (1), m represents an integer of 0 to 3, and R ^{11 to} R ¹⁴ are the same or different and are each a hydrogen atom, a halogen atom, an alkyl group, a cycloalkyl group, an alkenyl group, an alkynyl group, an alkoxy group. , An alkoxyalkyl group, an alkoxycarbonyl group, or an alkoxycarbonylalkyl group. ]
[In the formula (2), n represents an integer of 0 to 3, and R ^{21 to} R ²⁴ are the same or different and each represent a hydrogen atom, a halogen atom, an alkyl group, a cycloalkyl group, an alkenyl group, an alkynyl group, an alkoxy group. , An alkoxyalkyl group, an alkoxycarbonyl group, or an alkoxycarbonylalkyl group. ] The infrared absorbing filter according to any one of claims 1 to 5 , wherein the silane coupling agent having an amino group is a silane coupling agent having a primary amino group. It used to form the infrared absorption layer as claimed in claim 1, and a cycloolefin-based resin, wherein is represented by formula (3), and not having a phthalocyanine compound an ester bond, a silane coupling having an amino group And a resin composition. Imaging device characterized by having an infrared absorption filter according to any one of claims 1-6.