JP7845020B2 - Composition for optical sensors, optical sensors, and solid-state imaging devices and camera modules using the optical filters. - Google Patents

Description

This invention relates to a composition for optical sensors and an optical sensor.

Video cameras, digital cameras, and mobile phones with camera functions are equipped with solid-state image sensors, which are optical sensors. Specifically, known solid-state image sensors include CCD (Charge-Coupled Device) image sensors and CMOS (Complementary MOS) image sensors. The sensitivity of the photodiodes in these solid-state image sensors extends from the visible light region to the infrared region. Therefore, solid-state image sensors are equipped with filters to block infrared light. These optical filters (infrared blocking filters) allow the sensitivity of the solid-state image sensor to be adjusted to approximate human visual sensitivity. Similarly, optical sensors other than solid-state image sensors may also be equipped with filters to block infrared light.

The optical filter described above contains dyes or pigments as infrared shielding agents. These infrared shielding agents are required to have the property of absorbing infrared rays while sufficiently transmitting visible light. As one such infrared shielding agent, the use of phthalocyanine compounds has been investigated, particularly as a good shielding agent for near-infrared rays (see Japanese Patent Publication No. 2008-201952).
Furthermore, a pattern-forming composition containing a squarylium compound along with an acrylic polymer is disclosed for the purpose of suppressing developing residue, improving pattern shape, and heat resistance (Japanese Patent No. 6903143).

Japanese Patent Publication No. 2008-201952 Patent No. 6903143

However, with the increasing demand for high-performance optical characteristics in recent years, obtaining sufficient performance has become difficult, and further improvements are desired. Furthermore, with the diversification of applications for optical sensors, there is a need for optical filters that can withstand more severe environments. On the other hand, from the perspective of production process margins, there is also a desire for infrared shielding films that have few defects such as foreign matter, even after curing after being left to stand for a period of time after coating in the production process. Considering these circumstances, there has been a need for optical sensor compositions that balance optical properties with heat resistance and storage stability.

The present invention has been made based on the circumstances described above, and its objective is to provide an optical sensor composition that can form an optical filter for an optical sensor having excellent properties with respect to the visible light transmission window range, infrared shielding range, heat resistance, chemical resistance, suppression of coating defects after low-temperature storage, and suppression of coating defects after long-term low-temperature storage.

The invention made to solve the above problems is an optical sensor composition containing (a1) at least one selected from the group consisting of unsaturated carboxylic acids and unsaturated carboxylic acid anhydrides, (a2) a copolymer (P) of an unsaturated mixture containing at least one selected from the group consisting of oxiranyl group-containing unsaturated compounds and oxetanyl group-containing unsaturated compounds, and a dye [Q] which is a polymethine compound.

According to the present invention, it is possible to provide an optical sensor composition that can form an optical filter for an optical sensor having excellent properties with respect to the visible light transmission window range, infrared shielding range, heat resistance, chemical resistance, suppression of coating defects after low-temperature storage, and suppression of coating defects after long-term low-temperature storage.

The following describes in detail an optical sensor composition according to one embodiment of the present invention.
<Composition for optical sensors>
The optical sensor composition of the present invention contains a copolymer (P) of an unsaturated mixture comprising (a1) at least one selected from the group consisting of unsaturated carboxylic acids and unsaturated carboxylic acid anhydrides, and (a2) at least one selected from the group consisting of oxiranyl group-containing unsaturated compounds and oxetanyl group-containing unsaturated compounds, and a dye [Q] containing at least one polymethine compound.

(Pigment [Q])
(Polymethine compounds)
The polymethine-based compounds used in the present invention are polymethine dyes other than squarylium-based compounds, crokonium-based compounds, and cyanine-based compounds, and are not particularly limited as long as they do not impair the effects of the present invention. For example, the compounds described in Japanese Patent Application Publication No. 2019-164269 can be used, and they can be synthesized by generally known methods.

• Polymethine compounds (iii)
As the aforementioned polymethine-based compound, a compound represented by the following formula (III) is preferred, in that it allows for easy acquisition of optical filters that exhibit the aforementioned effects more effectively.

Cn ⁺ An ^- (III)
[In formula (III), Cn ⁺ is a monovalent cation represented by formula (IV) or formula (VI) below, and ^An- is a monovalent anion.

In formulas (IV) and (VI),
Unit A is one of the following equations (A-I) to (A-III):
Unit B is one of the following equations (B-I) to (B-III):
Z _A to Z _C and Y _A to Y _I are each independently a hydrogen atom, a halogen atom, a hydroxyl group, a carboxyl group, a nitro group, a -NR ^g R ^h group, an amide group, an imide group, a cyano group, a silyl group, -Q ¹ , -N=N-Q ¹ , -S-Q ² , -SSQ ² , or -SO ₂ Q ³ .
Among Z _A to Z _C and Y _A to Y _I , two adjacent elements may be linked to each other to form a ring.
Some groups in unit A may be bonded to Y _A or Y _F to form a cyclic hydrocarbon group having 5 or 6 carbon atoms, and some groups in unit B may be bonded to Y _E or Y _I to form a cyclic hydrocarbon group having 5 or 6 carbon atoms.
R ^g and R ^h are independently a hydrogen atom, a -C(O)R ⁱ group, or one of the following L ^a to L ^h ; Q ¹ is independently one of the following L ^a to L ^h ; Q ² is independently a hydrogen atom or one of the following L ^a to L ^h ; Q ³ is a hydroxyl group or one of the following L ^a to L ^h ; and ^Ri is one of the following L ^a to L ^h .

In formulas (A-I) to (A-III), the -* indicates that Y _A or Y _F in formula (IV) forms a single bond with the carbon atom to which it is bonded.
In formulas (B-I) to (B-III), the =** indicates that Y _E or Y _I in formula (IV) is double-bonded to the carbon atom to which it is bonded.
In formulas (AI) to (B-III),
X is independently an oxygen atom, a sulfur atom, a selenium atom, a tellurium atom, or ^-NR8- .
^R1 to ^R6 are each independently a hydrogen atom, a halogen atom, a sulfo group, a hydroxyl group, a cyano group, a nitro group, a carboxyl group, a phosphoric acid group, an -NR ^g R ^h group, an -SR ⁱ group, an -SO ₂ ^Ri group, an -OSO ₂ ^Ri group, an -C(O) ^Ri group, or one of the following L ^a to L ^h .
Adjacent ^R1 to ^R6 may bond to each other to form a 4-7 membered alicyclic group containing at least one C6-C14 aromatic hydrocarbon group, a nitrogen atom, an oxygen atom, or a sulfur atom, or a C3-C14 heteroaromatic group containing at least one nitrogen atom, an oxygen atom, or a sulfur atom. These aromatic hydrocarbon groups, alicyclic groups, and heteroaromatic groups may also have a hydroxyl group, a C1-C9 aliphatic hydrocarbon group, or a halogen atom, and the alicyclic group may also have =O.
^R8 is independently a hydrogen atom, a halogen atom, a -C(O) ^Ri group, or one of the following L ^a to L ^h .
^Ri is independently one of the following L ^a to L ^h :
(L ^a ): Aliphatic hydrocarbon group having 1 to 15 carbon atoms (L ^b ): Halogen-substituted alkyl group having 1 to 15 carbon atoms (L ^c ): Alicyclic hydrocarbon group having 3 to 14 carbon atoms, which may have substituent K (L ^d ): Aromatic hydrocarbon group having 6 to 14 carbon atoms, which may have substituent K (L ^e ): Heterocyclic group having 3 to 14 carbon atoms, which may have substituent K (L ^f ): -OR (R is a hydrocarbon group having 1 to 12 carbon atoms, which may have substituent L)
(L ^g ): A carbon 1 to 9 acyl group which may have substituent L. (L ^h ): A carbon 1 to 9 alkoxycarbonyl group which may have substituent L. The substituent K is at least one selected from L ^a to L ^b , and the substituent L is at least one selected from L ^a to L ^f .

Furthermore, the ^-NR8- group is represented by the following formula (a), ^{the -NRgRh} group is represented by the following formula (b), the ^-SRi group is represented by the following formula (c), the _-SO2Ri group is represented by the following formula (d), _the ^{-OSO2Ri group} is represented by the following formula (e), and the -C(O)Ri group is represented by the following formula (f ⁾ .

Furthermore, ^-SSQ2 is a group represented as -S-S- ^Q2 , and _-SO2Q3 is a group in ^{which Ri} is replaced with ^Q3 in the group represented by the following formula (d).

Furthermore, if unit A is formula (A-I) and unit B is formula (B-I), then Cn ⁺ is represented by the following formula (IV-1) or formula (VI-1). In other words, the single bond (-) of "*-" in formulas (A-I) to (A-III) corresponds to the single bond between unit A and the carbon atom to which Y _A in formula (IV) or Y _F in formula (VI) below is bonded, and the double bond (=) of "**=" in formulas (B-I) to (B-III) corresponds to the double bond between unit B and the carbon atom to which Y _E in formula (IV) or Y _I in formula (VI) below is bonded.

The _YB and _YD , _YG and _YH are each independently, more preferably, a hydrogen atom, a chlorine atom, a fluorine atom, a methyl group, an ethyl group, and a 4-6 membered alicyclic hydrocarbon group formed by the bonding of _YB and _YD to each other (the alicyclic hydrocarbon group may have a hydrogen atom, an aliphatic hydrocarbon group having 1 to 9 carbon atoms, a hydroxyl group, a halogen atom, and a substituent ^R9 selected from =O).

Furthermore, if _YB and _YD are 4- to 6-membered alicyclic hydrocarbon groups formed by bonding with each other, formula (IV) can preferably be represented by the following formulas (IV-A) to (IV-C), and if _YG and _YH are 4- to 6-membered alicyclic hydrocarbon groups formed by bonding with each other, formula (VI) can preferably be represented by the following formulas (VI-A) to (VI-B).

Preferred substituents ^R9 include a hydrogen atom, a hydroxyl group, an O molecule, a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, a tert-butyl group, and a cyclohexyl group, with hydrogen atoms, hydroxyl groups, an O molecule, a methyl group, an ethyl group, and a tert-butyl group being more preferred.

Each of the aforementioned Y _A , Y _C , Y _E , and Z _A to Z _C may independently preferably contain a hydrogen atom, a halogen atom, a hydroxyl group, a carboxyl group, a nitro group, an -NR ^g R ^h group, an amide group, an imide group, a cyano group, a silyl group, -Q ¹ , -N=N-Q ¹ , -S-Q ² , -SSQ ² , -SO ₂ Q ³ , or two adjacent members from the aforementioned Y _A , Y _C , Y _E , and Z _A to Z _C may bond to each other to form a C6 to C14 aromatic hydrocarbon group: a 5 to 6 membered alicyclic group which may contain at least one nitrogen atom, an oxygen atom, or a sulfur atom; or a C3 to C14 heteroaromatic group which contains at least one nitrogen atom, an oxygen atom, or a sulfur atom; and these alicyclic groups, aromatic hydrocarbon groups, and heteroaromatic groups may also contain a C1 to C9 aliphatic hydrocarbon group or a halogen atom.

The aforementioned L ^a is preferably a methyl group (Me), an ethyl group (Et), an n-propyl group, an isopropyl group (i-Pr), an n-butyl group, a sec-butyl group, a tert-butyl group (tert-Bu), a pentyl group, a hexyl group, an octyl group, a nonyl group, a decyl group, or a dodecyl group, and more preferably a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, or a tert-butyl group.

The aforementioned L ^a may be an alkenyl group such as a vinyl group, a 1-propenyl group, a 2-propenyl group, a butenyl group, a 1,3-butadienyl group, a 2-methyl-1-propenyl group, a 2-pentenyl group, or a hexenyl group; or an alkynyl group such as an ethynyl group, a propynyl group, a butynyl group, a 2-methyl-1-propynyl group, or a hexynyl group.

Examples of halogen-substituted alkyl groups having 1 to 15 carbon atoms in ^Lb include groups in which at least one hydrogen atom of the alkyl group having 1 to 15 carbon atoms is substituted with a halogen atom, and are preferably trichloromethyl, trifluoromethyl, 1,1-dichloroethyl, pentachloroethyl, pentafluoroethyl, heptachloropropyl, and heptafluoropropyl groups.

Examples of alicyclic hydrocarbon groups having 3 to 14 carbon atoms that may have a substituent K in ^Lc include, preferably, cycloalkyl groups such as cyclopropyl group, cyclopropylmethyl group, methylcyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, methylcyclohexyl group, cycloheptyl group, and cyclooctyl group; and polycyclic alicyclic groups such as norbornane group and adamantyl group.

The C6-C14 aromatic hydrocarbon group that may have substituent K in ^Ld is preferably a phenyl group, a tolyl group, a xylyl group, a mesityl group (trimethylphenyl group), a cumenyl group, a bis(trifluoromethyl)phenyl group, a 1-naphthyl group, a 2-naphthyl group, anthracenyl group, a phenanthryl group, or a benzyl group ( _CH2Ph ).

The heterocyclic group having 3 to 14 carbon atoms in ^Le may preferably be furan, thiophene, pyrrole, indole, indoline, indorenine, benzofuran, benzothiophene, morpholine, or pyridine.

The -OR in ^Lf is preferably a methoxy group, ethoxy group, propoxy group, isopropoxy group, butoxy group, methoxymethyl group, methoxyethyl group, pentyloxy group, hexyloxy group, octyloxy group, phenoxy group (OPh), 4-methylphenoxy group, or cyclohexyloxy group.

The carbon-1 to carbon-9 acyl group in L ^g that may have substituent L is preferably an acetyl group, a propionyl group, a butyryl group, an isobutyryl group, a benzoyl group, a 4-propylbenzoyl group, or a trifluoromethylcarbonyl group.

The C1-C9 alkoxycarbonyl group that may have substituent L in ^Lh is preferably a methoxycarbonyl group, an ethoxycarbonyl group, a propoxycarbonyl group, an isopropoxycarbonyl group, a butoxycarbonyl group, a 2-trifluoromethylethoxycarbonyl group, or a 2-phenylethoxycarbonyl group.

The aforementioned X is preferably an oxygen atom, a sulfur atom, or ^-NR8- , and is particularly preferably an oxygen atom.

In formulas (IV) and (VI), the left and right units A and B may be identical or different, but it is preferable that they be identical because it is easier to combine them.

Note that the combinations in which units A and B are identical are equations (A-I) and (B-I), equations (A-II) and (B-II), and equations (A-III) and (B-III).

Each of the ^R1 to ^R6 is preferably independently a hydrogen atom, a chlorine atom, a fluorine atom, a bromine atom, a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, a tert-butyl group, a 1,1-dimethylbutyl group, a cyclopropyl group, a cyclopropylmethyl group, a cyclohexyl group, an adamantyl group, a phenyl group, a 2,4,6-trimethylphenyl group, a 3,5-bis(trifluoromethyl)phenyl group, a hydroxyl group, an amino group, a dimethylamino group ( _NMe2 ), a diethylamino group ( _NET2 ), or a dibutylamino group (N(n-Bu) ₂ ). ), cyano group, nitro group, acetylamino group, propionylamino group, N-methylacetylamino group, trifluoromethanoylamino group, pentafluoroethanolamino group, tert-butanoylamino group, cyclohexinoylamino group, n-butylsulfonyl group, benzyl group, diphenylmethyl group, trifluoromethyl group, difluoromethyl group, methoxy group, more preferably hydrogen atom, chlorine atom, fluorine atom, bromine atom, methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, cyclohexyl group, phenyl group, amino group, benzyl group, diphenylmethyl group, trifluoromethyl group, difluoromethyl group, methoxy group.

It is preferable that at least one of ^R1 to ^R6 is La, Lc, or Ld, as ^this allows for easy acquisition of compounds that have high near-infrared cutting performance and high visible light transmission performance at absorption maximums around wavelengths of 700 to 750 nm or 720 to 900 nm, excellent optical properties, and sufficient resistance to heat and light. When unit A is formula (A-III) and unit B is formula (B-III), "at least one of ^R1 to ^R6 is ^La , ^Lc , ^{or Ld} " means "at least one of ^R1 , ^R2 , ^R4 , and ^R5 is ^La , ^{Lc ,} or ^Ld ."

The ^R8 is preferably a hydrogen atom, a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a benzyl group, an n-pentyl group, an n-hexyl group, or a tert-butyl group, and more preferably a hydrogen atom, a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, or a benzyl group.

The aforementioned ^An- is not particularly limited as long as it is a monovalent anion, but preferably includes chloride ions, bromide ions, iodide ions, _PF4- ^, perchlorate anions, tristrifluoromethanesulfonylmethide anions, tetrafluoroborate anions, hexafluorophosphate anions, bis(trifluoromethanesulfonyl)imide anions, trifluoromethanesulfonic acid anions, tetrakis(pentafluorophenyl)borate anions, tetrakis(3,5-bis(trifluoromethyl)phenyl)borate anions, and more preferably bis(trifluoromethanesulfonyl)imide anions, trifluoromethanesulfonic acid anions, tristrifluoromethanesulfonylmethide anions, The tetrakis(pentafluorophenyl)borate anion and the tetrakis(3,5-bis(trifluoromethyl)phenyl)borate anion are preferred, and more preferably, the bis(trifluoromethanesulfonyl)imide anion, tritrifluoromethanesulfonylmethide anion, tetrakis(pentafluorophenyl)borate anion, and tetrakis(3,5-bis(trifluoromethyl)phenyl)borate anion are preferred, particularly the tetrakis(pentafluorophenyl)borate anion, as these allow for easy acquisition of compounds with superior heat resistance.

Specific examples of compounds (III) having a monovalent cation represented by formula (IV) include the following compounds (III-1) to (III-3).

Specific examples of compounds (III) having a monovalent cation represented by formula (VI) include the following compounds (III-4) to (III-6).

In this invention, the above-mentioned polymethine compound is included as an essential component as the dye [Q].
The polymethine compound is present in an amount of 20% by mass or more, preferably 30% by mass or more, and more preferably 40% by mass or more, of the total dye [Q]. By including a predetermined amount of the polymethine compound in this way, an optical sensor composition with excellent properties such as long-term low-temperature storage, heat resistance, and chemical resistance can be obtained.
The dye [Q] may further contain a squarylium-based compound.

(Squallium compounds)
The squarylium-based compound used in the present invention is preferably a compound represented by the following formula (I) or a compound represented by the following formula (II) (hereinafter also referred to as "compound (I)" and "compound (II)," respectively).
・Compound (I)

In equation (I), ^Ra , ^Rb , and Y satisfy either condition (i) or (ii) below.

(i) Each of the multiple R ^{a groups} independently represents a hydrogen atom, a halogen atom, a sulfo group, a hydroxyl group, a cyano group, a nitro group, a carboxyl group, a phosphoric acid group, or an -L ¹ or -NR ^e R ^f group (where R ^e and R ^f independently represent a hydrogen atom, -L ^a , -L ^b , -L ^c , -L ^d , or -L ^e , respectively).
The multiple R ^b groups independently represent a hydrogen atom, a halogen atom, a sulfo group, a hydroxyl group, a cyano group, a nitro group, a carboxyl group, a phosphoric acid group, an -L ¹ or -NR ^g R ^h group (R ^g and R ^h independently represent a hydrogen atom, ^-La , -L ^b , -L ^c , -L ^d , ^-Le , -SO ₂ ^Ri group, or -C(O)R ⁱ group (R ⁱ represents -La, -L ^b , -L ^c , -L ^{d ,} or ^-Le ; however, multiple ^Ri in R ^g and R ^h bonded to the same N atom may bond to each other to form a ring)).
The multiple Ys independently represent ^{-NRj Rk} groups (where ^Rj and ^Rk independently represent a hydrogen atom, ^-La , ^-Lb , ^-Lc , ^-Ld , or ^-Le , respectively).
^L1 is,
(L ^a ) A C1 to C20 aliphatic hydrocarbon group which may have a substituent L,
(L ^b ) A halogen-substituted alkyl group with 1 to 20 carbon atoms which may have substituent L,
(L ^c ) A cycloaliphatic hydrocarbon group having 3 to 20 carbon atoms, which may have a substituent L.
(L ^d ) A C6-C20 aromatic hydrocarbon group which may have substituent L,
A heterocyclic group having 3 to 20 carbon atoms, which may have a substituent L (L ^e ),
(L ^f ) A carbon-1 to carbon-20 alkoxy group which may have a substituent L,
(L ^g ) represents a carbon 1 to carbon 20 acyl group which may have substituent L, or (L ^h ) represents a carbon 1 to carbon 20 alkoxycarbonyl group which may have substituent L, wherein substituent L is at least one selected from the group consisting of carbon 1 to carbon 20 aliphatic hydrocarbon groups, carbon 1 to carbon 20 halogen-substituted alkyl groups, carbon 3 to carbon 20 alicyclic hydrocarbon groups, carbon 6 to carbon 20 aromatic hydrocarbon groups, and carbon 3 to carbon 20 heterocyclic groups, and L ^a to L ^h may further have at least one atom or group selected from the group consisting of halogen atoms, sulfo groups, hydroxyl groups, cyano groups, nitro groups, carboxyl groups, phosphoric acid groups, and amino groups. Preferably, the total number of carbon atoms including substituents in L ^a to L ^h is 50 or less, more preferably 40 or less, and particularly preferably 30 or less. If the number of carbon atoms is greater than this range, it may become difficult to synthesize the dye, and the absorption intensity per unit mass tends to decrease.

(ii) At least one of the two Ra ^atoms on one benzene ring is bonded to Y on the same benzene ring to form a heterocycle with 5 or 6 constituent atoms, which contains at least one nitrogen atom, and the heterocycle may have substituents.
R ^b and R ^a , which are not involved in the formation of the hetero ring, are independently synonymous with R ^b and R ^a in condition (i).

• Compound (II)

In formula (II), the multiple R ^cs independently represent a hydrogen atom, -L ^a , -L ^b , -L ^c , -L ^d , or -L ^e ,
The multiple R ^d groups independently represent a hydrogen atom, a halogen atom, a sulfo group, a hydroxyl group, a cyano group, a nitro group, a carboxyl group, a phosphoric acid group, or a -L ¹ or -NR ^e R ^f group, and adjacent R ^d groups may be linked to form a ring which may have substituents.
X represents O, S, Se, N-R ^c or C-R ^d R ^d ,
L ^a to L ^e , L ¹ , Re ^e , and R ^f are synonymous with L ^a to L ^e , L ¹ , Re ^e , and R ^f as defined in formula (I) above.

In formula (II), R ^c is preferably a hydrogen atom, a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, an n-hexyl group, a cyclohexyl group, a phenyl group, a tolfluoromethyl group, or a pentafluoroethyl group, and more preferably a hydrogen atom, a methyl group, an ethyl group, an n-propyl group, or an isopropyl group.

In formula (II), R ^d is preferably a hydrogen atom, a chlorine atom, a fluorine atom, a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, an n-hexyl group, a cyclohexyl group, a phenyl group, a methoxy group, a trifluoromethyl group, a pentafluoroethyl group, or a 4-aminocyclohexyl group, and more preferably a hydrogen atom, a chlorine atom, a fluorine atom, a methyl group, an ethyl group, an n-propyl group, an isopropyl group, a trifluoromethyl group, or a pentafluoroethyl group.

The aforementioned X is preferably O, S, Se, N-Me, N-Et, _CH2 , C- _Me2 , C- _Et2 , and more preferably S, C- _Me2 , C- _Et2 .

In formula (II) above, adjacent R ^d elements may be linked together to form a ring. Examples of such rings include a benzoindorenine ring, an α-naphthoimidazole ring, a β-naphthoimidazole ring, an α-naphthoxazole ring, a β-naphthoxazole ring, an α-naphthothiazole ring, a β-naphthothiadazole ring, an α-naphthoserenazole ring, and a β-naphthoserenazole ring.

Compounds (I) and (II) may adopt resonance structures as described in International Patent Publication WO2013/054864.
Specific examples of compound (I) and compound (II) include the following compounds (I-D-1) to (I-D-4).

(Other organic pigments)
The composition may contain other known organic dyes in addition to polymethine compounds and squarylium compounds. Examples of other organic dyes include phthalocyanine compounds, diiminium compounds, cyanine compounds, naphthalocyanine compounds, quaterylene compounds, aminium compounds, iminium compounds, azo compounds, anthraquinone compounds, porphyrin compounds, pyrrolopyrrole compounds, oxonol compounds, crokonium compounds, hexaphylline compounds, etc. (excluding those containing copper atoms).

(Copolymer (P))
The copolymer (P) used in the present invention is a copolymer of (a1) at least one selected from the group consisting of unsaturated carboxylic acids and unsaturated carboxylic acid anhydrides (hereinafter sometimes referred to as "compound (a1)") and (a2) at least one selected from the group consisting of oxiranyl group-containing unsaturated compounds and oxetanyl group-containing unsaturated compounds (hereinafter sometimes referred to as "compound (a2)"). Such copolymers can be produced by radical copolymerization of an unsaturated mixture containing compounds (a1) and (a2) in a solvent in the presence of a polymerization initiator.

Compound (a1) is a radically polymerizable unsaturated carboxylic acid and/or unsaturated carboxylic acid anhydride, and examples include monocarboxylic acids, dicarboxylic acids, anhydrides of dicarboxylic acids, mono[(meth)acryloyloxyalkyl] esters of polycarboxylic acids, mono(meth)acrylates of polymers having carboxyl groups and hydroxyl groups at both ends, polycyclic compounds having carboxyl groups and their anhydrides.

Specific examples of these include monocarboxylic acids such as acrylic acid, methacrylic acid, and crotonic acid;
Examples of dicarboxylic acids include maleic acid, fumaric acid, citraconic acid, mesaconic acid, and itaconic acid;
Examples of dicarboxylic acid anhydrides include the anhydrides of the compounds exemplified above as dicarboxylic acids;
Examples of mono[(meth)acryloyloxyalkyl] esters of polycarboxylic acids include mono[2-(meth)acryloyloxyethyl] succinate and mono[2-(meth)acryloyloxyethyl] phthalate;
As a mono(meth)acrylate of a polymer having a carboxyl group and a hydroxyl group at both ends, for example, ω-carboxypolycaprolactone mono(meth)acrylate;
Examples of polycyclic compounds having a carboxyl group and their anhydrides include 5-carboxybicyclo[2.2.1]hept-2-ene, 5,6-dicarboxybicyclo[2.2.1]hept-2-ene, 5-carboxy-5-methylbicyclo[2.2.1]hept-2-ene, 5-carboxy-5-ethylbicyclo[2.2.1]hept-2-ene, 5-carboxy-6-methylbicyclo[2.2.1]hept-2-ene, 5-carboxy-6-ethylbicyclo[2.2.1]hept-2-ene, and 5,6-dicarboxybicyclo[2.2.1]hept-2-ene anhydride.

Of these, monocarboxylic acids and dicarboxylic acid anhydrides are preferably used, and in particular, acrylic acid, methacrylic acid, and maleic anhydride are preferred due to their ability to enhance copolymerization reactivity, heat resistance, and chemical resistance of the film, as well as their easy availability. These compounds (a1) can be used individually or in combination of two or more.

Compound (a2) is an unsaturated compound having an oxiranil group and/or an unsaturated compound having an oxetanyl group. Examples of unsaturated compounds having an oxiranil group include glycidyl acrylate, glycidyl methacrylate, α-ethyl glycidyl acrylate, α-n-propyl glycidyl acrylate, α-n-butyl glycidyl acrylate, 3,4-epoxybutyl acrylate, 3,4-epoxybutyl methacrylate, 6,7-epoxyheptyl acrylate, 6,7-epoxyheptyl methacrylate, α-ethyl acrylate, 3,4-epoxycyclohexyl acrylate, 3,4-epoxycyclohexyl methacrylate, 3,4-epoxycyclohexylmethyl acrylate, 3,4-epoxycyclohexylmethyl methacrylate, o-vinylbenzylglycidyl ether, m-vinylbenzylglycidyl ether, and p-vinylbenzylglycidyl ether. Of these, glycidyl methacrylate, 6,7-epoxyheptyl methacrylate, o-vinylbenzylglycidyl ether, m-vinylbenzylglycidyl ether, p-vinylbenzylglycidyl ether, 3,4-epoxycyclohexyl methacrylate, and 3,4-epoxycyclohexylmethyl methacrylate are preferred for their copolymerization reactivity and for improving the heat resistance and chemical resistance of the resulting film.

Examples of unsaturated compounds having an oxetanyl group include 3-(acryloyloxymethyl)oxetane, 3-(acryloyloxymethyl)-2-methyloxetane, 3-(acryloyloxymethyl)-3-ethyloxetane, 3-(acryloyloxymethyl)-2-trifluoromethyloxetane, 3-(acryloyloxymethyl)-2-pentafluoroethyloxetane, 3-(acryloyloxymethyl)-2-phenyloxetane, 3-(acryloyloxymethyl)-2,2-difluorooxetane, 3-(acryloyloxymethyl)-2,2,4-trifluorooxetane, 3-(acryloyloxymethyl)-2,2,4,4-tetrafluorooxetane, 3- Acrylic acid esters such as (2-acryloyloxyethyl)oxetane, 3-(2-acryloyloxyethyl)-2-ethyloxetane, 3-(2-acryloyloxyethyl)-3-ethyloxetane, 3-(2-acryloyloxyethyl)-2-trifluoromethyloxetane, 3-(2-acryloyloxyethyl)-2-pentafluoroethyloxetane, 3-(2-acryloyloxyethyl)-2-phenyloxetane, 3-(2-acryloyloxyethyl)-2,2-difluorooxetane, 3-(2-acryloyloxyethyl)-2,2,4-trifluorooxetane, 3-(2-acryloyloxyethyl)-2,2,4,4-tetrafluorooxetane, etc.
3-(methacryloyloxymethyl)oxetane, 3-(methacryloyloxymethyl)-2-methyloxetane, 3-(methacryloyloxymethyl)-3-ethyloxetane, 3-(methacryloyloxymethyl)-2-trifluoromethyloxetane, 3-(methacryloyloxymethyl)-2-pentafluoroethyloxetane, 3-(methacryloyloxymethyl)-2-phenyloxetane, 3-(methacryloyloxymethyl)-2,2-difluorooxetane, 3-(methacryloyloxymethyl)-2,2,4-trifluorooxetane, 3-(methacryloyloxymethyl)-2,2,4,4-tetrafluorooxetane, 3-(2-methacryloyloxyethyl)oxetane Examples of methacrylic acid esters such as tan, 3-(2-methacryloyloxyethyl)-2-ethyloxetane, 3-(2-methacryloyloxyethyl)-3-ethyloxetane, 3-(2-methacryloyloxyethyl)-2-tolylololomethyloxetane, 3-(2-methacryloyloxyethyl)-2-pentafluoroethyloxetane, 3-(2-methacryloyloxyethyl)-2-phenyloxetane, 3-(2-methacryloyloxyethyl)-2,2-difluorooxetane, 3-(2-methacryloyloxyethyl)-2,2,4-trifluorooxetane, and 3-(2-methacryloyloxyethyl)-2,2,4,4-tetrafluorooxetane can be listed.

Of these, 3-(acryloyloxymethyl)-2-methyloxetane, 3-(acryloyloxymethyl)-3-ethyloxetane, 3-(methacryloyloxymethyl)-2-methyloxetane, and 3-(methacryloyloxymethyl)-3-ethyloxetane are preferred from the viewpoint of copolymerization reactivity.

These compounds (a2) can be used individually or in combination.

The copolymer (P) has a mass ratio (a2)/(a1) of repeating units derived from compound (a1) to repeating units derived from compound (a2) of 1 or more, preferably 1.1 or more, and more preferably 1.2 or more. This ratio provides high low-temperature storage stability, allows for long-term storage, and yields a composition with excellent heat resistance, chemical resistance, and other properties.
It is preferable that the constituent unit (a2) derived from (a2) is present in an amount of 10% by mass or more, preferably 15% by mass or more, and more preferably 20% by mass or more, relative to the total constituent units of the copolymer. Within this range, a composition can be obtained that has high low-temperature storage stability, can be stored for a long period of time, and has excellent heat resistance, chemical resistance, etc.

The copolymer (P) used in the present invention is a copolymer of the above compounds (a1) and (a2). Furthermore, it may be a copolymer of these with other unsaturated compounds (hereinafter sometimes referred to as "compound (a3)").
Such compounds (a3) are not particularly limited as long as they are unsaturated compounds having radical polymerizability, but examples include alkyl methacrylates, cyclic alkyl methacrylates, alkyl acrylates, cyclic alkyl acrylates, aryl methacrylates, aryl acrylates, unsaturated dicarboxylic acid diesters, methacrylate esters having hydroxyl groups, bicyclounsaturated compounds, maleimide compounds, unsaturated aromatic compounds, conjugated dienes, unsaturated compounds having a tetrahydrofuran skeleton, a furan skeleton, a tetrahydropyran skeleton, a pyran skeleton, or a (poly)alkylene glycol skeleton, unsaturated compounds having phenolic hydroxyl groups, and other unsaturated compounds.

Specific examples of these include alkyl methacrylates such as methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, sec-butyl methacrylate, t-butyl methacrylate, 2-ethylhexyl methacrylate, isodecyl methacrylate, n-lauryl methacrylate, tridecyl methacrylate, and n-stearyl methacrylate; and cyclic methacrylates such as cyclohexyl methacrylate, 2-methylcyclohexyl methacrylate, tricyclo[5.2.1.0 ^2,6 ]decane-8-yl methacrylate (hereinafter referred to as "dicyclopentanyl methacrylate"), and tricyclo[5.2.1.0 ^2,6 ] ] Decane-8-yloxyethyl methacrylate, isobolonyl methacrylate, adamantane-1-yl methacrylate, etc.; as alkyl acrylates, for example, methyl acrylate, ethyl acrylate, n-propyl acrylate, i-propyl acrylate, n-butyl acrylate, sec-butyl acrylate, t-butyl acrylate, etc.; as cyclic acrylates, for example, cyclohexyl acrylate, 2-methylcyclohexyl acrylate, tricyclo[5.2.1.0 ^2,6 ]decane-8-yl acrylate (hereinafter referred to as "dicyclopentanyl acrylate"), tricyclo[5.2.1.0 ^2,6 ] Decane-8-yloxyethyl acrylate, isoboronyl acrylate, adamantane-1-yl acrylate, etc.; aryl acrylates, for example, phenyl acrylate, benzyl acrylate, etc.; aryl methacrylates, for example, phenyl methacrylate, benzyl methacrylate, etc.; unsaturated dicarboxylic acid diesters, for example, diethyl maleate, diethyl fumarate, diethyl itaconate, etc.; methacrylic acid esters having a hydroxyl group, for example, hydroxymethyl methacrylate, 2-hydroxyethyl methacrylate, 3-hydroxypropyl methacrylate, 4-hydroxybutyl methacrylate, diethylene glycol monomethacrylate, 2,3-dihydroxypropyl methacrylate, 2-methacryloxyethyl glycoside, etc.
Examples of bicyclounsaturated compounds include: bicyclo[2.2.1]hept-2-ene,5-methylbicyclo[2.2.1]hept-2-ene,5-ethylbicyclo[2.2.1]hept-2-ene,5-hydroxybicyclo[2.2.1]hept-2-ene,5-carboxybicyclo[2.2.1]hept-2-ene,5-hydroxymethylbicyclo[2.2.1]hept-2-ene,5-(2-hydroxyethyl)bicyclo[2.2.1]hept-2-ene,5-methoxybicyclo[2.2.1]hept-2-ene,5-ethoxybicyclo[2.2.1]hept-2-ene,5,6-dihydroxybicyclo[2.2.1]hept-2-ene,5,6-dicarboxybicyclo[2.2.1] Hept-2-ene, 5,6-di(hydroxymethyl)bicyclo [2.2.1] Hept-2-ene, 5,6-di(2-hydroxyethyl)bicyclo [2.2.1] Hept-2-ene, 5,6-dimethoxybicyclo [2.2.1] Hept-2-ene, 5,6-diethoxybicyclo [2.2.1] Hept-2-ene, 5-hydroxy-5-methylbicyclo [2.2.1] Hept-2-ene, 5-hydroxy-5-ethylbicyclo [2.2.1] Hept-2-ene, 5-carboxy-5-methylbicyclo [2.2.1] Hept-2-ene, 5-hydroxymethyl-5-methylbicyclo [2.2.1] Hept-2-ene, 5-carboxy-6-methylbicyclo [2.2.1] Hept-2-ene, 5-carboxy-6-ethylbicyclo [2.2.1] Hept-2-ene, 5,6-dicarboxybicyclo [2.2.1] Hept-2-ene anhydride (Hymic acid anhydride), 5-t-butoxycarbonylbicyclo [2.2.1] Hept-2-ene, 5-cyclohexyloxycarbonylbicyclo [2.2.1] Hept-2-ene, 5-phenoxycarbonylbicyclo [2.2.1] Hept-2-ene, 5,6-di(t-butoxycarbonyl)bicyclo [2.2.1] Hept-2-ene, 5,6-di(cyclohexyloxycarbonyl)bicyclo [2.2.1] Hept-2-ene, etc.
Examples of maleimide compounds include N-phenylmaleimide, N-cyclohexylmaleimide, N-benzylmaleimide, N-(4-hydroxyphenyl)maleimide, N-(4-hydroxybenzyl)maleimide, N-succinimidyl-3-maleimide benzoate, N-succinimidyl-4-maleimide butyrate, N-succinimidyl-6-maleimide caproate, N-succinimidyl-3-maleimide propionate, N-(9-acridinyl)maleimide, etc.
Examples of unsaturated aromatic compounds include styrene, α-methylstyrene, m-methylstyrene, p-methylstyrene, vinyltoluene, p-methoxystyrene, etc.; examples of conjugated dienes include 1,3-butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, etc.; examples of unsaturated compounds containing a tetrahydrofuran skeleton include tetrahydrofurfuryl (meth)acrylate, 2-methacryloyloxypropionic acid tetrahydrofurfuryl ester, 3-(meth)acryloyloxytetrahydrofuran-2-one, etc.; examples of unsaturated compounds containing a furan skeleton include 2-methyl-5-(3-furyl)-1-penten-3-one, furfuryl (meth)acrylate, 1-furan-2-butyl-3-en-2-one, 1-furan-2-butyl-3-methoxy-3-en-2-one, 6-(2-furyl)- Examples include 2-methyl-1-hexen-3-one, 6-furan-2-yl-hexy-1-en-3-one, 2-furan-2-yl-1-methyl-ethyl acrylate, 6-(2-furyl)-6-methyl-1-hepten-3-one, etc.; and unsaturated compounds containing a tetrahydropyran skeleton, such as (tetrahydropyran-2-yl)methyl methacrylate and 2,6-dimethyl-8-(tetrahydropyran-2-yl) Examples of unsaturated compounds containing a pyran skeleton include 4-(1,4-dioxa-5-oxo-6-heptenyl)-6-methyl-2-pyrone, 4-(1,5-dioxa-6-oxo-7-octenyl)-6-methyl-2-pyrone, etc.
Examples of unsaturated compounds having a (poly)alkylene glycol skeleton include polyethylene glycol (n=2-10) mono(meth)acrylate and polypropylene glycol (n=2-10) mono(meth)acrylate;
Examples of unsaturated compounds having phenolic hydroxyl groups include 4-hydroxybenzyl(meth)acrylate, 4-hydroxyphenyl(meth)acrylate, o-hydroxystyrene, p-hydroxystyrene, α-methyl-p-hydroxystyrene, N-(4-hydroxybenzyl)(meth)acrylamide, N-(3,5-dimethyl-4-hydroxybenzyl)(meth)acrylamide, and N-(4-hydroxyphenyl)(meth)acrylamide;
Other unsaturated compounds include, for example, acrylonitrile, methacrylonitrile, vinyl chloride, vinylidene chloride, acrylamide, methacrylamide, and vinyl acetate.

Of these, alkyl methacrylates, cyclic alkyl methacrylates, cyclic alkyl acrylates, maleimide compounds, unsaturated aromatic compounds, conjugated dienes, tetrahydrofuran skeletons, furan skeletons, tetrahydropyran skeletons, pyran skeletons, unsaturated compounds having (poly)alkylene glycol skeletons, and unsaturated compounds having phenolic hydroxyl groups are preferably used.
In particular, the inclusion of an unsaturated compound having an alicyclic structure is preferred from the viewpoint of heat resistance. Examples of unsaturated compounds having an alicyclic structure include cyclic alkyl methacrylates and cyclic alkyl acrylates.

These compounds (a3) can be used individually or in combination of two or more.

The copolymer (P) used in this invention contains repeating units derived from compound (a1) in an amount preferably 5 to 40% by mass, and particularly preferably 5 to 25% by mass, based on the total amount of repeating units derived from compounds (a1), (a2), and (a3). This range tends to enhance the heat resistance and chemical resistance of the film.

Furthermore, the copolymer (P) used in this invention contains repeating units derived from compound (a2) in an amount of preferably 10 to 80% by mass, and particularly preferably 20 to 60% by mass, based on the total amount of repeating units derived from compounds (a1), (a2), and (a3). This range tends to enhance the heat resistance and chemical resistance of the film.

Furthermore, in the copolymer (P) used in the present invention, when an unsaturated compound having an alicyclic structure is used as compound (a3), the repeating units derived therefrom may be preferably 10 to 80% by mass, and particularly preferably 20 to 60% by mass, based on the total of the repeating units derived from compounds (a1), (a2), and (a3), in order to further enhance the heat resistance of the film.

The polystyrene-based mass-average molecular weight (hereinafter referred to as "Mw") of the copolymer (P) used in the present invention is preferably 2 × ^10³ to 1 × ^10⁵ , more preferably 5 × ^10³ to 5 × ^10⁴ . Furthermore, the molecular weight distribution (hereinafter referred to as "Mw/Mn") is preferably 5.0 or less, more preferably 3.0 or less.

Copolymer (P) can be synthesized, for example, by polymerizing compound (a1), compound (a2), and compound (a3) in a suitable solvent in the presence of a radical polymerization initiator.

Examples of solvents used in the production of copolymer [A] include alcohols, ethers, glycol ethers, ethylene glycol alkyl ether acetate, diethylene glycol, propylene glycol monoalkyl ether, propylene glycol alkyl ether acetate, propylene glycol alkyl ether propionate, aromatic hydrocarbons, ketones, and esters.

Specific examples of these include, as alcohols, methanol, ethanol, benzyl alcohol, 2-phenylethyl alcohol, 3-phenyl-1-propanol, etc.; as ethers, tetrahydrofuran, etc.
Examples of glycol ethers include ethylene glycol monomethyl ether and ethylene glycol monoethyl ether;
Examples of ethylene glycol alkyl ether acetates include methyl cellosolve acetate, ethyl cellosolve acetate, ethylene glycol monobutyl ether acetate, and ethylene glycol monoethyl ether acetate;
Examples of diethylene glycols include diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, and diethylene glycol ethyl methyl ether;
Examples of propylene glycol monoalkyl ethers include propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, and propylene glycol monobutyl ether;
Examples of propylene glycol alkyl ether propionates include propylene glycol methyl ether propionate, propylene glycol ethyl ether propionate, propylene glycol propyl ether propionate, and propylene glycol butyl ether propionate;
Examples of propylene glycol alkyl ether acetates include propylene glycol methyl ether acetate, propylene glycol ethyl ether acetate, propylene glycol propyl ether acetate, and propylene glycol butyl ether acetate;
Examples of aromatic hydrocarbons include toluene and xylene;
Examples of ketones include methyl ethyl ketone, cyclohexanone, and 4-hydroxy-4-methyl-2-pentanone;
As esters, for example, methyl acetate, ethyl acetate, propyl acetate, butyl acetate, ethyl 2-hydroxypropionate, methyl 2-hydroxy-2-methylpropionate, ethyl 2-hydroxy-2-methylpropionate, methyl hydroxyacetate, ethyl hydroxyacetate, butyl hydroxyacetate, methyl lactate, ethyl lactate, propyl lactate, butyl lactate, methyl 3-hydroxypropionate, ethyl 3-hydroxypropionate, propyl 3-hydroxypropionate, butyl 3-hydroxypropionate, methyl 2-hydroxy-3-methylbutanoate, methyl methoxyacetate, ethyl methoxyacetate, propyl methoxyacetate, butyl methoxyacetate, methyl ethoxyacetate, ethyl ethoxyacetate, propyl ethoxyacetate, butyl ethoxyacetate, methyl propoxyacetate, ethyl propoxyacetate, propyl propoxyacetate, butyl propoxyacetate, methyl butoxyacetate, ethyl butoxyacetate, propyl butoxyacetate, butyl butoxyacetate, methyl 2-methoxypropionate, ethyl 2-methoxypropionate, 2-Propyl methoxypropionate, 2-butyl methoxypropionate, 2-methyl ethoxypropionate, 2-ethyl ethoxypropionate, 2-propyl ethoxypropionate, 2-butyl ethoxypropionate, 2-methyl ethoxypropionate, 2-ethyl ethoxypropionate, 2-propyl ethoxypropionate, 2-butyl ethoxypropionate, 3-methyl methoxypropionate, 3-ethyl methoxypropionate, 3-propyl methoxypropionate, 3-methoxypropionic acid Examples of esters include butyl, methyl 3-ethoxypropionate, ethyl 3-ethoxypropionate, propyl 3-ethoxypropionate, butyl 3-ethoxypropionate, methyl 3-propoxypropionate, ethyl 3-propoxypropionate, propyl 3-propoxypropionate, butyl 3-propoxypropionate, methyl 3-butoxypropionate, ethyl 3-butoxypropionate, propyl 3-butoxypropionate, and butyl 3-butoxypropionate.

Of these, ethylene glycol alkyl ether acetate, diethylene glycol, propylene glycol monoalkyl ether, and propylene glycol alkyl ether acetate are preferred, and in particular, diethylene glycol dimethyl ether, diethylene glycol ethyl methyl ether, propylene glycol methyl ether, propylene glycol ethyl ether, propylene glycol methyl ether acetate, and methyl 3-methoxypropionate are preferred.

For the production of copolymers (P), polymerization initiators known as radical polymerization initiators can be used. Examples include azo compounds such as 2,2'-azobisisobutyronitrile, 2,2'-azobis-(2,4-dimethylvaleronitrile), and 2,2'-azobis-(4-methoxy-2,4-dimethylvaleronitrile); organic peroxides such as benzoyl peroxide, lauroyl peroxide, t-butylperoxypivalate, and 1,1'-bis-(t-butylperoxy)cyclohexane; and hydrogen peroxide. When using peroxides as radical polymerization initiators, they may also be used together with a reducing agent to act as redox initiators.

In the production of copolymers (P), molecular weight modifiers can be used to adjust the molecular weight. Specific examples include halogenated hydrocarbons such as chloroform and carbon tetrabromide; mercaptans such as n-hexyl mercaptan, n-octyl mercaptan, n-dodecyl mercaptan, tert-dodecyl mercaptan, and thioglycolic acid; xanthogens such as dimethyl xanthogen sulfide and diisopropyl xanthogen disulfide; and terpinolene and α-methylstyrene dimer.

The lower limit of the copolymer (P) content in the total solids of the composition is preferably 60% by mass, more preferably 70% by mass, and even more preferably 80% by mass. By setting the copolymer (P) content within the above range, the heat resistance and other properties can be enhanced while fully exhibiting the visible light transmittance and infrared shielding properties of the resulting optical filter. Furthermore, other polymers besides copolymer (P) may be used in combination with the composition, provided they do not impair the physical properties.

([C] Other infrared shielding agents)
The composition may further contain [C] other infrared shielding agents. The other infrared shielding agents are infrared shielding agents other than the aforementioned squarylium, polymethine, and other organic dyes, and are preferably metal oxides, copper compounds, or combinations thereof. The [C] other infrared shielding agents are preferably compounds having a maximum absorption wavelength in the range of 800 nm to 2000 nm. The [C] other infrared shielding agents may be used individually or in combination of two or more.

[C] Other examples of metal oxides used as infrared shielding agents include tungsten oxide compounds, quartz ( _SiO₂ ), magnetite ( _Fe₃O₄ ), alumina ( _{Al₂O₃ )} , titania ( _TiO₂ ), _zirconia ( _ZrO₂ ), and spinel ( _{MgAl₂O₄ )} .

[C] Other infrared shielding agents include metal oxides, and more preferably tungsten oxide compounds. Tungsten oxide compounds are infrared shielding agents that have high absorption (i.e., high shielding against infrared light) for infrared light (especially infrared light with wavelengths of approximately 800 nm to 1200 nm) and low absorption for visible light.

The tungsten oxide compound is more preferably a tungsten oxide compound represented by the following formula (3).

A _x WO _y ...(3)
In equation (3), A is a metallic element. 0.001 ≤ x ≤ 1.1. 2.2 ≤ y ≤ 3.0.

Examples of metal elements represented by A in formula (3) above include alkali metals, alkaline earth metals, Mg, Zr, Cr, Mn, Fe, Ru, Co, Rh, Ir, Ni, Pd, Pt, Cu, Ag, Au, Zn, Cd, Al, Ga, In, Tl, Sn, Pb, Ti, Nb, V, Mo, Ta, Re, Be, Hf, Os, Bi, etc. The metal element represented by A may be one or more.

As for A above, alkali metals are preferred, Rb and Cs are more preferred, and Cs is even more preferred. That is, the metal oxide is more preferably tungsten cesium oxide.

When x in formula (3) above is 0.001 or greater, infrared radiation can be sufficiently shielded. The lower limit of x is preferably 0.01, and more preferably 0.1. On the other hand, when x is 1.1 or less, the formation of impurity phases in the tungsten oxide-based compound can be more reliably avoided. The upper limit of x is preferably 1, and more preferably 0.5.

By setting y in formula (3) above to 2.2 or higher, the chemical stability of the material can be further improved. A lower limit of y is preferably 2.5. On the other hand, by setting y to 3.0 or lower, infrared radiation can be sufficiently shielded.

Specific examples of tungsten oxide compounds represented by the above formula (3) include Cs _{0.33 WO3} , Rb _{0.33 WO3} , K _{0.33 WO3} , Ba _{0.33 WO3,} etc., with Cs _{0.33 WO3} and Rb _{0.33 WO3} being preferred, and Cs _{0.33 WO3} being even more preferred.

[C] As other copper compounds used as infrared shielding agents, copper complexes are preferred. Preferred copper complexes are those composed of copper and a compound (ligand) having a coordination site for copper. Examples of coordination sites for copper include anionic coordination sites and lone pairs of electrons. A copper complex may have two or more ligands. If it has two or more ligands, they may be identical or different. Examples of copper complexes include 4-coordination, 5-coordination, and 6-coordination, with 4-coordination and 5-coordination being more preferred, and 5-coordination being even more preferred.

Copper complexes can be obtained, for example, by mixing or reacting a copper component (copper or a copper-containing compound) with a compound (ligand) that has a coordination site for copper. The compound (ligand) with a coordination site for copper may be a low-molecular-weight compound or a polymer. Both can also be used in combination.

The copper component is preferably a compound containing divalent copper. One type of copper component may be used, or two or more types may be used. Examples of copper components include copper oxide and copper salts. Examples of copper salts include copper carboxylates (e.g., copper acetate, copper ethylacetoacetate, copper formate, copper benzoate, copper stearate, copper naphthenate, copper citrate, copper 2-ethylhexanoate, etc.), copper sulfonates (e.g., copper methanesulfonate, etc.), copper phosphate, copper phosphate esters, copper phosphonates, copper phosphonate esters, copper phosphinate, copper amide, copper sulfonamide, copper imide, copper acylsulfonimide, copper bissulfonimide, copper methide, copper alkoxy, copper phenoxy, copper hydroxide, and carbonic acid. Copper, copper sulfate, copper nitrate, copper perchlorate, copper fluoride, copper chloride, and copper bromide are preferred; copper carboxylate, copper sulfonate, copper sulfonamide, copper imide, copper acylsulfonimide, copper bissulfonimide, copper alkoxy, copper phenoxy, copper hydroxide, copper carbonate, copper fluoride, copper chloride, copper sulfate, and copper nitrate are more preferred; copper carboxylate, copper acylsulfonimide, copper phenoxy, copper chloride, copper sulfate, and copper nitrate are even more preferred; and copper carboxylate, copper acylsulfonimide, copper chloride, and copper sulfate are particularly preferred.

[C] Other infrared shielding agents are preferably fine particles. The upper limit for the average particle size (D50) of [C] other infrared shielding agents is preferably 500 nm, more preferably 200 nm, even more preferably 50 nm, and even more preferably 30 nm. By keeping the average particle size below the above upper limit, visible light transmittance can be further enhanced. On the other hand, for reasons such as ease of handling during manufacturing, the average particle size of [C] other infrared shielding agents is usually 1 nm or more, and may also be 10 nm or more.

[C] Other infrared shielding agents can be synthesized by known methods, but they are also available commercially. When the metal oxide is, for example, a tungsten oxide compound, the tungsten oxide compound can be obtained, for example, by heat-treating a tungsten compound in an inert gas atmosphere or a reducing gas atmosphere. Furthermore, tungsten oxide compounds are also available as dispersions of tungsten fine particles, such as Sumitomo Metal Mining's "YMF-02".

The lower limit of the total infrared shielding agent content in the composition is preferably 0.1% by mass, more preferably 0.5% by mass, even more preferably 1% by mass, and still more preferably 2% by mass. On the other hand, the upper limit of this content is preferably 50% by mass, more preferably 40% by mass, even more preferably 30% by mass, and still more preferably 20% by mass. Here, the total infrared shielding agent includes the dye [Q], other organic dyes, [C], and other infrared shielding agents. By setting the infrared shielding agent content within the above range, the visible light transmittance and infrared shielding properties of the resulting optical filter are improved.

([D] Dispersant)
The composition may further contain a [D] dispersant. The [D] dispersant enhances the uniform dispersibility of [C] other infrared shielding agents (especially metal oxides), resulting in better visible light transmittance and infrared shielding properties of the resulting optical filter.

[D] Examples of dispersants include urethane-based dispersants, polyethyleneimine-based dispersants, polyoxyethylene alkyl ether-based dispersants, polyoxyethylene alkylphenyl ether-based dispersants, polyethylene glycol diester-based dispersants, sorbitan fatty acid ester-based dispersants, polyester-based dispersants, and (meth)acrylic-based dispersants. Among these, (meth)acrylic-based dispersants are preferred. [D] The dispersant is preferably a block copolymer.

([E] Polymerizable compound)
The composition may further contain an [E]polymerizable compound. When the composition contains an [E]polymerizable compound, it can exhibit good curability and good heat resistance of the resulting optical filter. An [E]polymerizable compound is a compound having two or more polymerizable groups. Examples of polymerizable groups include ethylenically unsaturated groups, oxyranyl groups, oxetanyl groups, and N-alkoxymethylamino groups. Preferred [E]polymerizable compounds are compounds having two or more (meth)acryloyl groups, two or more oxyranyl groups, and two or more N-alkoxymethylamino groups, and more preferably compounds having two or more (meth)acryloyl groups and two or more oxyranyl groups. One or more [E]polymerizable compounds can be used in combination.

Examples of compounds having two or more (meth)acryloyl groups include ethylene glycol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, polypropylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, bisphenoxyethanol full orange (meth)acrylate, bisphenoxyethanol full orange (meth)acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, tri((meth)acryloyloxyethyl) phosphate, pentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, and dipentaerythritol hexa(meth)acrylate.

Examples of compounds having two or more oxiranil groups include aliphatic epoxy compounds.
These are available commercially. For example, Denacol EX-611, EX-612, EX-614, EX-614B, EX-622, EX-512, EX-521, EX-411, EX-421, EX-313, EX-314, EX-321, EX-211, EX-212, EX-810, EX-811, EX-850, EX-851, EX-821, EX-830, EX-832, EX-841, EX-911, EX-941, EX-920, EX-931, Examples include EX-212L, EX-214L, EX-216L, EX-321L, EX-850L, DLC-201, DLC-203, DLC-204, DLC-205, DLC-206, DLC-301, DLC-402 (all manufactured by Nagase ChemteX Corporation), Celoxide 2021P, 2081, 3000, EHPE3150, Epolide GT401, Cellvinace B0134, B0177 (manufactured by Daicel Corporation), and others.
[E] The content of polymerizable compounds is preferably 20% by mass or more and 120% by mass or less, based on 100% by mass of the total amount of copolymer (P) components.

([F] Polymerization initiator)
The composition may contain a [F] polymerization initiator. Examples of [F] polymerization initiators include photopolymerization initiators and thermal polymerization initiators, but photopolymerization initiators are preferred. This allows the composition to be imparted with photosensitivity (radiation sensitivity). A photopolymerization initiator is a compound that generates active species capable of initiating polymerization of [E] polymerizable compounds, etc., upon exposure to radiation such as visible light, ultraviolet light, far ultraviolet light, electron beams, and X-rays. One or more [F] polymerization initiators can be used.

([G] Acid Generator)
The composition may contain a [G] acid generator. The [G] acid generator is a compound that generates acid upon irradiation with radiation. By containing the [G] acid generator, the composition can exhibit positive-type radiation sensitivity to, for example, alkaline developers. The [G] acid generator is not particularly limited as long as it is a compound that generates acid (e.g., carboxylic acid, sulfonic acid, etc.) upon irradiation with radiation. Examples of [G] acid generators include oxime sulfonate compounds, onium salts, sulfonimide compounds, halogen-containing compounds, diazomethane compounds, sulfone compounds, sulfonic acid ester compounds, carboxylic acid ester compounds, quinone diazide compounds, etc. Of these, quinone diazide compounds are preferred.

(Additives)
In addition to the components described above, the composition may also contain various additives as needed.

Examples of additives include surfactants, adhesion promoters, antioxidants, UV absorbers, anti-flocculation agents, residue improvers, developability improvers, and reaction modifiers.

Examples of surfactants include fluorinated surfactants and silicone surfactants.

Examples of adhesion promoters include vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris(2-methoxyethoxy)silane, N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-chloropropylmethyldimethoxysilane, 3-chloropropyltrimethoxysilane, 3-methacryloyloxypropyltrimethoxysilane, and 3-mercaptopropyltrimethoxysilane.

Examples of antioxidants include 2,2-thiobis(4-methyl-6-t-butylphenol), 2,6-di-t-butylphenol, pentaerythritol tetrakis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate], 3,9-bis[2-[3-(3-t-butyl-4-hydroxy-5-methylphenyl)-propionyloxy]-1,1-dimethylethyl]-2,4,8,10-tetraoxaspiro[5.5]undecane, and thiodiethylenebis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate].

Any conventionally known UV absorber capable of exhibiting UV absorption can be used. Among such UV absorbers, it is preferable to use benzotriazole-based or hydroxyphenyltriazine-based UV absorbers from the viewpoint of obtaining UV absorption capacity (UV blocking capacity). Furthermore, to broaden the UV absorption range, two or more UV absorbers with different maximum absorption wavelengths can be used in combination. Specific examples of UV absorbers include, for example, the compounds described in paragraphs [0258] to [0259] of Japanese Patent Application Publication No. 2012-18395, and the compounds described in paragraphs [0055] to [0105] of Japanese Patent Application Publication No. 2007-72163. Commercially available products such as Tinuvin 400, Tinuvin 405, Tinuvin 460, Tinuvin 477, Tinuvin 479, and Tinuvin 1577 (all manufactured by BASF) can also be used.

Examples of anti-flocculating agents include sodium polyacrylate.

Examples of residue-improving agents include malonic acid, adipic acid, itaconic acid, citraconic acid, fumaric acid, mesaconic acid, 2-aminoethanol, 3-amino-1-propanol, 5-amino-1-pentanol, 3-amino-1,2-propanediol, 2-amino-1,3-propanediol, and 4-amino-1,2-butanediol.

Examples of developing agents include mono[2-(meth)acryloyloxyethyl] succinate, mono[2-(meth)acryloyloxyethyl] phthalate, ω-carboxypolycaprolactone mono(meth)acrylate, and others.

Examples of reaction modifiers include polyfunctional thiols.

(solvent)
The composition (I) is usually prepared as a liquid composition containing a solvent (dispersion medium). Any solvent can be appropriately selected and used, as long as it disperses or dissolves other components, does not react with these components, and has appropriate volatility.

Examples of such solvents include (poly)alkylene glycol monoalkyl ethers such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol mono-n-propyl ether, ethylene glycol mono-n-butyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol mono-n-propyl ether, diethylene glycol mono-n-butyl ether, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol mono-n-butyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol mono-n-propyl ether, dipropylene glycol mono-n-butyl ether, tripropylene glycol monomethyl ether, and tripropylene glycol monoethyl ether.
Alkyl lactate esters such as methyl lactate and ethyl lactate,
(Cyclo)alkyl alcohols such as methanol, ethanol, propanol, butanol, isopropanol, isobutanol, t-butanol, octanol, 2-ethylhexanol, and cyclohexanol,
Keto alcohols such as diacetone alcohol,
(Poly)alkylene glycol monoalkyl ether acetates such as ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, propylene glycol monomethyl ether acetate, dipropylene glycol monomethyl ether acetate, 3-methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate, etc.
Other ethers such as diethylene glycol dimethyl ether, diethylene glycol methyl ethyl ether, diethylene glycol diethyl ether, and tetrahydrofuran,
Ketones such as methyl ethyl ketone, 2-heptanone, 3-heptanone and other linear ketones, and cyclopentanone and cyclohexanone and other cyclic ketones.
Diacetates such as propylene glycol diacetate, 1,3-butylene glycol diacetate, and 1,6-hexanediol diacetate,
Alkoxycarboxylic acid esters such as methyl 3-methoxypropionate, ethyl 3-methoxypropionate, methyl 3-ethoxypropionate, ethyl 3-ethoxypropionate, ethyl ethoxyacetate, and methyl-3-methoxybutylpropionate,
Ethyl acetate, n-propyl acetate, i-propyl acetate, n-butyl acetate, i-butyl acetate, n-amyl formate, i-amyl acetate, n-butyl propionate, ethyl butyrate, n-propyl butyrate, i-propyl butyrate, n-butyl butyrate, methyl pyruvate, ethyl pyruvate, n-propyl pyruvate, methyl acetoacetate, ethyl acetoacetate, ethyl 2-oxobutanoate, and other esters,
Aromatic hydrocarbons such as toluene and xylene,
Examples include amides or lactams such as N,N-dimethylformamide, N,N-dimethylacetamide, and N-methylpyrrolidone.

The solvent content in the composition is not particularly limited. The lower limit of the solid content concentration (total concentration of each component excluding the solvent) in the composition is preferably 5% by mass, and more preferably 10% by mass. On the other hand, the upper limit of this solid content concentration is preferably 50% by mass, and more preferably 40% by mass. By setting the solid content concentration within the above range, dispersibility, stability, and coatability are improved.

(Preparation method)
The method for preparing the composition is not particularly limited and can be prepared by mixing the components. The composition can be filtered as needed to remove aggregates.

<Infrared shielding film>
An infrared shielding film for optical filters can be formed from the composition of the present invention. This infrared shielding film has good properties in terms of visible light transmission window range, infrared shielding range, heat resistance, and chemical resistance.

The infrared shielding film can be formed, for example, by the following method. First, the composition is applied to a support, and then pre-baking is performed to evaporate the solvent and form a coating film. Afterward, post-baking is performed to obtain the infrared shielding film. If development is required, after the coating film is formed, it is exposed to light, and then developed using a developer to dissolve and remove the unexposed areas of the coating film. Afterward, post-baking is performed to obtain an infrared shielding film patterned into a predetermined shape.

The support to which the composition is applied includes the transparent substrate, microlens, color filter, etc. The application can be carried out using an appropriate method such as spray coating, roll coating, rotary coating (spin coating), slit die coating (slit coating), or bar coating.

The heating and drying conditions in the above pre-bake process are, for example, 70°C to 110°C, for 1 minute to 10 minutes.

When developing a coating, suitable light sources for exposure include lamps such as xenon lamps, halogen lamps, tungsten lamps, high-pressure mercury lamps, ultra-high-pressure mercury lamps, metal halide lamps, medium-pressure mercury lamps, and low-pressure mercury lamps, as well as lasers such as argon ion lasers, YAG lasers, XeCl excimer lasers, and nitrogen lasers. Ultraviolet LEDs can also be used as exposure light sources. The wavelength of the radiation is preferably in the range of 190 nm to 450 nm. The radiation exposure dose is generally between 10 J/ ^m² and 50,000 J/ ^m² .

The developer used is generally an alkaline developer. Preferred alkaline developers include aqueous solutions of sodium carbonate, sodium bicarbonate, sodium hydroxide, potassium hydroxide, tetramethylammonium hydroxide, choline, 1,8-diazabicyclo-[5.4.0]-7-undecene, and 1,5-diazabicyclo-[4.3.0]-5-nonene. Appropriate amounts of water-soluble organic solvents such as methanol and ethanol, or surfactants, can also be added to the alkaline developer. After development, the image is usually washed with water.

For development, shower development, spray development, dip development, and paddle development can be applied. Development conditions are approximately 5 to 300 seconds at room temperature.

The typical post-bake conditions are between 180°C and 280°C, and for between 1 minute and 60 minutes.

The lower limit of the average thickness of the infrared shielding film formed in this manner is typically 0.5 μm, with 1 μm being preferred. On the other hand, the upper limit of this average thickness is typically 20 μm, with 10 μm being preferred. Having the average thickness of the infrared shielding film within the above range provides a better balance between visible light transmittance and infrared shielding properties.

<Optical filters>
An infrared shielding film formed from a composition according to one embodiment of the present invention can be used in an optical filter. An optical filter having the above infrared shielding film has few defects such as foreign matter and has good characteristics regarding visible light transmittance and infrared shielding. This optical filter can be used as an optical filter for optical sensors such as solid-state image sensors.

The optical filter may consist solely of the infrared shielding film, or it may consist of the infrared shielding film and other components. For example, the optical filter may be a laminate having the infrared shielding film and other layers.

The infrared shielding film is preferably incorporated as a component into an optical sensor such as a solid-state image sensor. In this case, the infrared shielding film functions as an optical filter (infrared cut filter) on its own. Incorporating the infrared shielding film into the optical sensor is preferable because it allows for the acquisition of a large process margin. When the infrared shielding film is incorporated into a solid-state image sensor, it can be placed, for example, on the outer surface of the microlenses of the solid-state image sensor, between the microlenses and the color filter, or between the color filter and the photodiode. It is preferable that the infrared shielding film is laminated between the microlenses and the color filter, or between the color filter and the photodiode.

The above-mentioned optical filter may consist of an infrared shielding film laminated on the surface of a transparent substrate. The transparent substrate may be glass, transparent resin, or the like. Examples of transparent resins include polycarbonate, polyester, aromatic polyamide, polyamide-imide, and polyimide. To shield a wider range of light from the near-infrared to the infrared region, the optical filter may have a dielectric multilayer film on the infrared shielding film or on the transparent substrate. Examples of the dielectric multilayer film include a laminate in which high-refractive-index material layers and low-refractive-index material layers are alternately laminated. Alternatively, instead of providing the dielectric multilayer film directly on the infrared shielding film laminate, another transparent substrate having a dielectric multilayer film may be separately disposed within the element. Such optical filters are also suitably used as infrared cut filters in solid-state image sensors.

Optical sensors, such as solid-state image sensors equipped with the above-mentioned optical filters, are useful in digital still cameras, mobile phone cameras, digital video cameras, PC cameras, surveillance cameras, automotive cameras, personal digital assistants (PDAs), personal computers, video games, medical devices, and the like.

<Optical Sensor>
The above-mentioned optical filter is used in optical sensors such as solid-state image sensors. Because the above-mentioned optical filter has few defects such as foreign matter and possesses good characteristics regarding visible light transmission and infrared shielding, optical sensors such as solid-state image sensors equipped with this optical filter have high sensitivity, color reproduction, etc., and are highly practical.

The following describes a solid-state image sensor as an example of an optical sensor. Generally, this solid-state image sensor has a structure in which layers of multiple photodiodes, color filters, and microlenses are stacked in that order. Planarization layers may also be provided between these layers. In this solid-state image sensor, light enters from the microlens side. The incident light passes through the microlenses and color filters and reaches the photodiodes. Regarding the color filters, for example, R (red), G (green), and B (blue) filters are configured to transmit only light within a specific wavelength range.

In the solid-state image sensor, the optical filter (infrared shielding film) can be provided on the outer surface of the microlens, between the microlens and the color filter, or between the color filter and the layer on which the multiple photodiodes are arranged. It is preferable that the optical filter is laminated between the microlens and the color filter, or between the color filter and the photodiodes. Furthermore, another layer (such as a planarization layer) may be provided between the optical filter and the microlens, color filter, photodiodes, etc.

Specific examples of such solid-state image sensors include CCDs and CMOS sensors used in camera modules. These solid-state image sensors are useful in digital still cameras, mobile phone cameras, digital video cameras, PC cameras, surveillance cameras, automotive cameras, personal digital assistants (PDAs), personal computers, video games, medical equipment, and the like.

The present invention will be described in detail below based on examples, but the present invention is not limited to these examples.

The abbreviations for the compounds are as follows. Note that, in the following, the compound represented by formula (X) may simply be referred to as "compound (X)".

M1: Methacrylic acid M2: Acrylic acid M3: Mono[2-(meth)acryloyloxyethyl] succinate
M4: Glycidyl methacrylate M5: 3,4-epoxycyclohexyl methacrylate M6: 3-(methacryloyloxymethyl)-2-methyloxetane M7: Styrene M8: Tricyclo[5.2.1.0 ^2,6 ]decane-8-yl methacrylate M9: Methyl methacrylate M10: Benzyl methacrylate M11: Cyclohexyl methacrylate M12: 1-adamantyl methacrylate Squallium 1: Compound represented by the above formula (I-D-1) Squallium 2: Compound represented by the above formula (I-D-2) Squallium 3: Compound represented by the above formula (I-D-4) Polymethine 1: Compound represented by the above formula (III-6) Polymethine 2: Compound represented by the above formula (III-2) Polymethine 3: Compound represented by the above formula (III-3) Polymerizable compound 1: Celoxide 2021P, manufactured by Daicel Corporation.
Other organic dyes 1: Daito Chemix 1371F (manufactured by Daito Chemix Co., Ltd.)
Other organic pigments 2: Compounds represented by the following formula (color-2)

UV absorber 1: Compound represented by the following formula (UVA-1)

UV absorber 2: Compound represented by the following formula (UVA-2)

Surfactant 1: KF-643 (silicone-based) manufactured by Shin-Etsu Chemical Co., Ltd.
Surfactant 2: Megafac F-474 (fluorine-based) manufactured by DIC Corporation
Adhesion promoter 1: γ-glycidoxypropyltrimethoxysilane Adhesion promoter 2: 3-aminopropyltriethoxysilane Antioxidant 1: Irganox 1010 (BASF)
Solvent 1: Cyclopentanone

(Synthesis Example 1)
In a flask equipped with a condenser and a stirrer, the unsaturated mixture was pre-charged to a total mass of 7% by mass of 2,2'-azobis(2,4-dimethylvaleronitrile) and 200% by mass of diethylene glycol ethyl methyl ether, with the unsaturated mixture being 100% by mass. An unsaturated mixture containing 20% by mass of methacrylic acid, 30% by mass of glycidyl methacrylate, and 50% by mass of methyl methacrylate, totaling 100% by mass, was added, and after purging with nitrogen, gentle stirring was started. The temperature of the solution was raised to 70°C and maintained at this temperature for 4 hours to terminate the polymerization. Subsequently, the reaction product solution was added dropwise to a large amount of methanol to solidify the reaction product. After washing this solidified material with water, it was redissolved in tetrahydrofuran and solidified again with a large amount of methanol. After repeating this redissolution-solidification operation a total of three times, the obtained solidified material was vacuum-dried at 60°C for 48 hours to obtain the target polymer [polymer 1].

In Synthesis Example 1, polymers [2] to [8] were obtained in the same manner as in Synthesis Example 1, except that the types and amounts of monomer components listed in Table 1 were used.

[Example 1]
When the above polymer 1 is considered to be 100% by mass, the following components were weighed into a container and mixed with a stirrer: 0.7% by mass of squarylium 1, 1.5% by mass of polymethine 1, 0.7% by mass of ultraviolet absorber 1, 1.8% by mass of adhesion promoter 1, 1.1% by mass of antioxidant 1, and 354% by mass of cyclopentanone as a solvent. This mixture was then filtered under constant pressure of 0.05 MPa using a 0.5 μm PTFE filter to obtain the composition of Example 1.

[Examples 2-6, Comparative Examples 1-9]
The compositions of Examples 2 to 6 and Comparative Examples 1 to 9 were obtained in the same manner as in Example 1, except that the types and blending ratios (mass%) of polymers, dyes, various additives, and solvents were as shown in Table 1.
[evaluation]
The following evaluations were performed using each of the obtained compositions. The evaluation results are shown in Table 1.

Each composition was applied to a glass substrate by spin coating to a predetermined thickness. The coating was then heated at 100°C for 120 seconds, followed by heating at 200°C for 300 seconds to create an infrared shielding film with an average thickness of 10 μm on the glass substrate. The film thickness was measured using a stylus-type step meter ("Alpha Step IQ" by Yamato Scientific Co., Ltd.). Next, the transmittance of the infrared shielding film fabricated on the glass substrate in each wavelength range was measured relative to the glass substrate using a spectrophotometer ("V-7300" by JASCO Corporation). The obtained spectra were evaluated according to the following criteria.

(Visible light transmission window range)
We determined the range in the 400-700 nm range where the transmittance is continuously 70% or higher. If the range with continuous transmittance of 70% or higher is 180 nm or longer, it is presumed to have high sensitivity when used as an infrared shielding film, thus indicating high practicality. Furthermore, the visible light transmission window range was evaluated according to the following criteria.
○: 180nm or higher △: 170nm or higher but less than 180nm ×: Less than 170nm

(Infrared shielding range)
We determined the range in the 600-1200 nm range where the transmittance is continuously 20% or less. If the range where the transmittance is continuously 20% or less is 70 nm or longer, it is presumed to have high practicality as an infrared shielding film because it has a high noise shielding function. Furthermore, the above infrared shielding range was evaluated according to the following criteria.
○: 70 nm or more ×: 40 nm or more but less than 70 nm ××: less than 40 nm

(heat resistance)
The infrared shielding film fabricated on the glass substrate described above was heated at 220°C for 30 minutes using a hot plate. The transmittance in each wavelength range before and after heating was measured relative to the glass substrate using a spectrophotometer (JASCO's "V-7300"). At this time, the absorbance at the wavelength in the 600-1200 nm range where the transmittance of the fabricated infrared shielding film was lowest was (A1), and the absorbance at the same wavelength after heating at 220°C was (A2). The heat resistance at 220°C was evaluated according to the following criteria, with the absorbance retention rate = 100 × (A2) / (A1). If the retention rate is 50% or higher, it is estimated that the film can maintain high heat resistance when used as an infrared shielding film, and is highly practical. Furthermore, the above retention rate was evaluated according to the following criteria.
◎: 80% or more ○: 50% or more but less than 80% △: 30% or more but less than 50% ×: Less than 30%

(Chemical resistance)
The infrared shielding film fabricated on the glass substrate described above was immersed in N-methyl-2-pyrrolidone in a petri dish for 10 minutes at room temperature. The transmittance in each wavelength range before and after immersion was measured relative to the glass substrate using a spectrophotometer (JASCO's "V-7300"). At this time, the absorbance at the wavelength in the 600-1200 nm range where the transmittance of the fabricated infrared shielding film was lowest was (A1), and the absorbance at the same wavelength after immersion in N-methyl-2-pyrrolidone was (A2). The absorbance retention rate was set to 100 × (A2) / (A1), and the chemical resistance was evaluated according to the following criteria. If the retention rate is 50% or higher, it is estimated that the film can maintain high chemical resistance when used as an infrared shielding film, and is highly practical. Furthermore, the above retention rate was evaluated according to the following criteria.
○: 50% or more △: 30% or more but less than 50% ×: Less than 30%

(Coating defects after low-temperature storage)
An infrared absorbing composition, left to stand at -15°C for one week, was applied to a silicon substrate using a spinner to form a coating with a thickness of 1 μm. The defect density of the coating was measured using a defect/foreign matter inspection device (KLA-Tencor's "KLA 2351"). A smaller defect density indicates higher foreign matter removal efficiency, i.e., that foreign matter has been sufficiently removed. Based on the above defect density, the foreign matter removal efficiency was evaluated according to the following criteria.
○: 10/ ^cm2 or less △: More than 10/ ^cm2 and less than 50/ ^cm2 ×: More than 50/ ^cm2

(Coating defects after long-term low-temperature storage)
An infrared-absorbing composition, left to stand at -15°C for two months, was applied to a silicon substrate using a spinner to form a coating with a thickness of 1 μm. The defect density of the coating was measured using a defect/foreign matter inspection device (KLA-Tencor's "KLA 2351"). A smaller defect density indicates higher foreign matter removal efficiency, i.e., that foreign matter has been sufficiently removed. Based on the above defect density, the foreign matter removal efficiency was evaluated according to the following criteria.
○: 10/ ^cm2 or less △: More than 10/ ^cm2 and less than 50/ ^cm2 ×: More than 50/ ^cm2

As shown in Table 1 above, all of Examples 1 to 6 showed good evaluations of visible light transmission window range, infrared shielding range, heat resistance, chemical resistance, and suppression of coating defects after low-temperature storage, and also exhibited high suppression of coating defects after long-term low-temperature storage.

The optical sensor composition of the present invention can be suitably used as a material for forming optical filters in optical sensors such as solid-state image sensors.

Claims (8)

(a1) A copolymer (P) of an unsaturated mixture containing at least one selected from the group consisting of unsaturated carboxylic acids and unsaturated carboxylic acid anhydrides, and (a2) at least one selected from the group consisting of oxiranyl group-containing unsaturated compounds and oxetanyl group-containing unsaturated compounds, and a dye [Q] containing at least one polymethine compound ,
A composition for optical sensors , wherein the polymethine compound comprises a compound represented by the following formula (III) .
Cn ⁺ An ^- (III)
[In formula (III), Cn ⁺ is a monovalent cation represented by formula (IV) or formula (VI) below, and An- ^is a monovalent anion.
In formulas (IV) and (VI),
Unit A is one of the following equations (A-I) to (A-III):
Unit B is one of the following equations (B-I) to (B-III):
Z _A to Z _C and Y _A to Y _I are each independently a hydrogen atom, a hydroxyl group, a carboxyl group, a nitro group, a -NR ^g R ^h group, an amide group, an imide group, a cyano group, a silyl group, -Q ¹ , -N=N-Q ¹ , -S-Q ² , -SSQ ² , or -SO ₂ Q ³ .
Among Z _A to Z _C and Y _A to Y _I , two adjacent elements may be linked to each other to form a ring.
Some groups in unit A may be bonded to Y _A or Y _F to form a cyclic hydrocarbon group having 5 or 6 carbon atoms, and some groups in unit B may be bonded to Y _E or Y _I to form a cyclic hydrocarbon group having 5 or 6 carbon atoms.
R ^g and R ^h are independently a hydrogen atom, a -C(O)R ⁱ group, or one of the following L ^a to L ^h ; Q ¹ is independently one of the following L ^a to L ^h ; Q ² is independently a hydrogen atom or one of the following L ^a to L ^h ; Q ³ is a hydroxyl group or one of the following L ^a to L ^h ; and ^Ri is one of the following L ^a to L ^h .
In formulas (A-I) to (A-III), the -* indicates that Y _A or Y _F in formula (IV) forms a single bond with the carbon atom to which it is bonded.
In formulas (B-I) to (B-III), the =** indicates that Y _E or Y _I in formula (IV) is double-bonded to the carbon atom to which it is bonded.
In formulas (AI) to (B-III),
X is independently an oxygen atom, a sulfur atom, a selenium atom, a tellurium atom, or ^-NR8- .
R1 ^to R6 are each independently a hydrogen atom, a halogen atom, a sulfo group, a hydroxyl group, a cyano group ^,
It is a nitro group, carboxyl group, phosphate group, -NR ^g R ^h group, -SR ⁱ group, -SO ₂ Ri group, -OSO ₂ Ri group, -C(O)R ⁱ group, or any of the following L ^a to ^L h ^groups .
Adjacent R1 ^to R6 ^may bond to each other to form a 4-7 membered alicyclic group containing at least one C6-C14 aromatic hydrocarbon group, a nitrogen atom, an oxygen atom, or a sulfur atom, or a C3-C14 heteroaromatic group containing at least one nitrogen atom, an oxygen atom, or a sulfur atom. These aromatic hydrocarbon groups, alicyclic groups, and heteroaromatic groups may also have a hydroxyl group, a C1-C9 aliphatic hydrocarbon group, or a halogen atom, and the alicyclic group may also have =O.
R8 ^is independently a hydrogen atom, a halogen atom, a -C(O)Ri ^group , or one of the following L ^a to L ^h .
Ri is independently one of the following ^{L a to} L ^h :
(L ^a ): Aliphatic hydrocarbon group having 1 to 15 carbon atoms
(L ^b ): Halogen-substituted alkyl group having 1 to 15 carbon atoms
(L ^c ): A cycloaliphatic hydrocarbon group having 3 to 14 carbon atoms, which may have a substituent K.
(L ^d ): A C6-C14 aromatic hydrocarbon group which may have a substituent K
(L ^e ): A heterocyclic group having 3 to 14 carbon atoms, which may have a substituent K.
(L ^f ): -OR (R is a C1-C12 hydrocarbon group which may have substituent L)
(L ^g ): Acyl group having 1 to 9 carbon atoms, which may have substituent L.
(L ^h ): A C1-C9 alkoxycarbonyl group which may have substituent L.
The substituent K is at least one selected from L ^a to L ^b , and the substituent L is at least one selected from L ^a to L ^f . The optical sensor composition according to claim 1, wherein a polymethine compound is contained in 20% by mass or more of the total dye [Q]. The optical sensor composition according to claim 1, wherein the mass ratio (a2)/(a1) of the constituent unit (a1) derived from (a1) in the copolymer (P) to the constituent unit (a2) derived from (a2) is 1 or more. The optical sensor composition according to claim 1, wherein the constituent unit (a2) derived from (a2) is present in an amount of 10% by mass or more relative to the total constituent units of the copolymer. The optical sensor composition according to claim 1, wherein the copolymer (P) is a copolymer of an unsaturated mixture further containing an unsaturated compound having an alicyclic structure. An optical sensor formed using the optical sensor composition described in claim 1. A solid-state image sensor characterized by comprising the optical sensor described in claim 6 . A camera module characterized by comprising the optical sensor described in claim 6 .