JP7326152B2 - Composition for solid-state imaging device and method for forming infrared shielding film for solid-state imaging device - Google Patents

Description

TECHNICAL FIELD The present invention relates to a composition for a solid-state imaging device and a method for forming an infrared shielding film for a solid-state imaging device.

2. Description of the Related Art Solid-state imaging devices such as CCD (Charge-Coupled Device) image sensors and CMOS (Complementary MOS) image sensors are mounted on video cameras, digital cameras, mobile phones with camera functions, and the like. The sensitivity of photodiodes provided in these solid-state imaging devices ranges from the visible light region to the infrared region. Therefore, the solid-state imaging device is provided with a filter for blocking infrared rays. This infrared cutoff filter can correct the sensitivity of the solid-state imaging device so as to approach human visual sensitivity.

The infrared blocking filter contains an organic dye or an inorganic compound as an infrared blocking agent (see JP-A-2013-137337 and JP-A-2013-151675). An infrared blocking filter is usually formed by coating a composition containing an infrared blocking agent on a substrate. In such an infrared blocking filter, the coating film of the above composition functions as a film that blocks infrared rays.

JP 2013-137337 A JP 2013-151675 A

Compositions for solid-state imaging devices are required to be capable of forming an optical filter having both good visible light transmittance and infrared shielding properties. Further, the composition for a solid-state imaging device is required to have high dispersion stability and long-term stability. If these are insufficient, the resulting optical filter (infrared shielding film) will have defects and productivity will be reduced. It also affects visible light transmittance and infrared shielding properties. Furthermore, the coating film may be exposed and developed to form a patterned infrared shielding film. In this case, the solid-state imaging device composition used is required to have good patterning properties. .

The present invention has been made based on the above circumstances, and an object of the present invention is to provide a solid-state imaging device having high dispersion stability and long-term stability, few defects, and good visible light transmission and infrared shielding properties. An object of the present invention is to provide a composition for a solid-state imaging device capable of forming an optical filter for the device, and a method for forming a shielding film for a solid-state imaging device using this composition for a solid-state imaging device.

An invention made to solve the above problems is a composition for a solid-state imaging device containing an inorganic compound, a polymer, an organic dye and a solvent, wherein the amine value of the polymer is 90 mgKOH/g or more and 200 mgKOH/g or less. , the solvent contains a specific solvent having a solubility parameter of 8.8 (cal/cm ³ ) ^1/2 or more and 12.0 (cal/cm ³ ) ^{1/2 or} less, and the composition for a solid-state imaging device of the specific solvent A composition for a solid-state imaging device, wherein the content of the organic dye in the entire product is 40% by mass or more and 90% by mass or less, and the solubility of the organic dye in the solvent at 20°C and 0.1 MPa is 2% by mass or more. .

Another invention made to solve the above problems is an infrared shielding device for a solid-state imaging device, comprising the step of forming a coating film on one surface side of a substrate, wherein the coating film is formed from the composition for a solid-state imaging device. It is a method of forming a film.

INDUSTRIAL APPLICABILITY According to the present invention, a composition for a solid-state imaging device is capable of forming an optical filter for a solid-state imaging device that has high dispersion stability and long-term stability, has few defects, and has both good visible light transmittance and infrared shielding properties. and a method for forming a shielding film for a solid-state imaging device using this composition for a solid-state imaging device.

Hereinafter, a composition for a solid-state imaging device and a method for forming an infrared shielding film for a solid-state imaging device according to one embodiment of the present invention will be described in detail.

<Composition for solid-state imaging device>
A composition for a solid-state imaging device according to one embodiment of the present invention (hereinafter also simply referred to as "composition") comprises [A] an inorganic compound, [B] a polymer, [C] an organic dye and [D] a solvent including. The [B] polymer is a polymer having an amine value of 90 mgKOH/g or more and 200 mgKOH/g or less. [D] The solvent is a specific solvent having a solubility parameter (hereinafter also referred to as "SP value") of 8.8 (cal/cm ³ ) ^1/2 or more and 12.0 (cal/cm ³ ) ^1/2 or less ( hereinafter also referred to as "[D1] solvent"). [D1] The content of the solvent in the solid-state imaging device composition is 40% by mass or more and 90% by mass or less. Further, the solubility of the [C] organic dye in the [D] solvent at 20° C. and 0.1 MPa is 2% by mass or more.

In the composition, the dispersibility of the [A] inorganic compound is improved by using the [B] polymer having a specific amine value. Furthermore, the dispersibility of the [A] inorganic compound can be enhanced by containing a predetermined amount of the [D1] solvent having a specific solubility parameter. [A] When the dispersibility of the compound is high, the optical filter to be obtained has good visible light transmittance and infrared shielding properties. In addition, by combining the highly soluble [C] organic dye and the [D] solvent, the above visible light transmittance, infrared shielding and the like are further improved. Therefore, according to the composition, it is possible to form an optical filter for a solid-state imaging device that has high dispersion stability and long-term stability, has few defects, and has both good visible light transmittance and infrared shielding properties.

Preferably, the composition further contains [E] a polymerizable compound, and additionally contains [F] a polymerization initiator. The composition may further contain other ingredients. Each component will be described in detail below.

([A] inorganic compound)
[A] The inorganic compound is a component that functions as an infrared shielding agent. [A] The inorganic compound may be a so-called pigment. [A] The inorganic compound preferably has a maximum absorption wavelength in the wavelength range of 800 nm or more and 2,000 nm or less. [A] The inorganic compound is in the form of particles and is dispersed in the composition.

[A] The inorganic compound is preferably an oxide of a metal or semimetal (such as silicon). [A] The inorganic oxide is preferably cesium tungsten oxide, quartz, magnetite, alumina, titania, zirconia, spinel, or a combination thereof. These inorganic compounds can be used individually by 1 type or in mixture of 2 or more types.

[A] As the inorganic compound, among these, cesium tungsten oxide is preferable. Cesium tungsten oxide has a high absorption of infrared rays (especially infrared rays with a wavelength of about 800 nm or more and 1,200 nm or less) (i.e., has a high shielding property against infrared rays), and an infrared shielding agent with low absorption of visible light. is. Therefore, by using cesium tungsten oxide, it is possible to improve the infrared shielding property while maintaining good visible light transmittance of the obtained optical filter.

Cesium tungsten oxide can be represented, for example, by the following formula (a): Cs _x WO _y (a)
In formula (A), 0.001≤x≤1.1. 2.2≤y≤3.0.

When x in the above formula (a) is 0.001 or more, infrared rays can be sufficiently shielded. The lower limit of x is preferably 0.01, more preferably 0.1. On the other hand, when x is 1.1 or less, it is possible to more reliably avoid the formation of an impurity phase in cesium tungsten oxide. The upper limit of x is preferably 1, more preferably 0.5.

When y in the formula (a) is 2.2 or more, the chemical stability of the material can be further improved. The lower limit of y is preferably 2.5. On the other hand, when y is 3.0 or less, infrared rays can be sufficiently shielded.

Specific examples of the cesium tungsten oxide represented by the formula (a) include Cs _0.33 WO ₃ and the like.

[A] The inorganic compound is preferably fine particles. [A] The upper limit of the average particle size (D50) of the inorganic compound is preferably 500 nm, more preferably 200 nm, even more preferably 50 nm, even more preferably 30 nm, and even more preferably 20 nm. When the average particle size is equal to or less than the above upper limit, the visible light transmittance can be further enhanced. On the other hand, the average particle size of the [A] inorganic compound is usually 1 nm or more, and may be 10 nm or more, for reasons such as ease of handling during production. The average particle size (D50) is the secondary particle size in the composition.

[A] The inorganic compound can be synthesized by a known method, and is available as a commercial product. For example, tungsten cesium oxide is also available as a dispersion of cesium tungsten oxide fine particles such as “YMF-02” from Sumitomo Metal Mining Co., Ltd.

The lower limit of the content of the [A] inorganic compound in the total solid content of the composition is preferably 1% by mass, more preferably 10% by mass, even more preferably 20% by mass, and even more preferably 30% by mass. On the other hand, the upper limit of this content is preferably 70% by mass, more preferably 60% by mass. [A] By setting the content of the inorganic compound within the above range, the visible light transmittance and infrared shielding properties of the resulting optical filter are well balanced. Moreover, the dispersion stability and aging stability of the composition can be improved. In addition, the total solid content refers to all components other than the [D] solvent.

([B] polymer)
The [B] polymer is a component that enhances the dispersibility of the [A] inorganic compound and the like. The [B] polymer may consist of one type of polymer, or may be a mixture of two or more types of polymers having the same or different amine values. A polymer having an amine value of 0 mgKOH/g is not included in the [B] polymer as a mixture of a plurality of types of polymers.

[B] The lower limit of the amine value of the polymer is 90 mgKOH/g, preferably 110 mgKOH/g, more preferably 130 mgKOH/g. On the other hand, the upper limit of this amine value is 200 mgKOH/g. By using a polymer having such an amine value, the dispersibility of the [A] inorganic compound can be improved, and the visible light transmittance and infrared shielding properties of the resulting optical filter can be further enhanced. The "amine value" is the number of mg of KOH equivalent to HCl required to neutralize 1 g of polymer solid content. When a mixture of a plurality of polymers having different amine values is used as the [B] polymer, the amine value of the [B] polymer is a weighted average value.

The [B] polymer is preferably a block copolymer. As the block copolymer, a block copolymer having an A block having a functional group containing a nitrogen atom and a B block having solvent affinity is preferable. A functional group containing a nitrogen atom in the A block exhibits good adsorptivity to the [A] inorganic compound. Therefore, by using a block copolymer having an A block and a B block, the dispersibility of the [A] inorganic compound can be further enhanced.

The A block preferably has a structural unit represented, for example, by the following formula (1).

In Formula (1), X is a divalent linking group. R ¹ is a hydrogen atom or a methyl group. R ² and R ³ are each independently a hydrogen atom, or a chain or cyclic hydrocarbon group which may have a substituent, or R ² and R ³ are bonded to each other, They form a ring structure together with the nitrogen atom to which they are attached.

Examples of X include a methylene group, an alkylene group having 2 to 10 carbon atoms, an arylene group, a group represented by -CONH-R ⁷ -(*), a group represented by -COO-R ⁸ -(*), and the like. can be mentioned. R ⁷ and R ⁸ are each independently a methylene group, an alkylene group having 2 to 10 carbon atoms, or an alkyleneoxyalkylene group having 2 to 10 carbon atoms. (*) indicates the binding site with N. X is preferably a group represented by —COO—R ⁸ —, and R ⁸ is preferably an alkylene group having 2 to 6 carbon atoms.

R ² and R ³ are preferably chain hydrocarbon groups, more preferably chain hydrocarbon groups having 1 to 5 carbon atoms, and even more preferably methyl, ethyl and propyl groups.

Examples of the monomer that provides the structural unit represented by the above formula (1) include dimethylaminoethyl (meth)acrylate, diethylaminoethyl (meth)acrylate, dimethylaminopropyl (meth)acrylate, diethylaminopropyl (meth)acrylate, and the like. can be mentioned.

The A block may contain structural units other than the structural unit represented by the above formula (1). The content of the A block in the block copolymer is preferably, for example, 30% by mass or more and 70% by mass or less.

The B block preferably has a structural unit represented, for example, by the following formula (2).

In formula (2), each R ⁴ is independently an alkylene group having 2 to 4 carbon atoms. R ⁵ is a hydrogen atom or an alkyl group having 1 to 6 carbon atoms. ^R6 is a hydrogen atom or a methyl group. n is an integer from 1 to 150;

R ⁴ is preferably an ethylene group and a methylethylene group. ^R5 is preferably a methyl group, an ethyl group, a propyl group or a butyl group. The upper limit of n is preferably 20, more preferably 10, and even more preferably 5.

Examples of the monomer that provides the structural unit represented by the above formula (2) include polyethylene glycol (n=1 to 5) methyl ether (meth) acrylate, polyethylene glycol (n=1 to 5) ethyl ether (meth) acrylate. , polyethylene glycol (n = 1 to 5) propyl ether (meth) acrylate, polypropylene glycol (n = 1 to 5) methyl ether (meth) acrylate, polypropylene glycol (n = 1 to 5) ethyl ether (meth) acrylate, polypropylene Glycol (n=1 to 5) propyl ether (meth)acrylate and the like can be mentioned.

The B block may contain a structural unit other than the structural unit represented by formula (2) above. Other structural units that the B block may contain include structural units derived from (meth)acrylic acid esters. Specific monomers that give other structural units include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, isopropyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) ) acrylate, phenyl (meth)acrylate, cyclohexyl (meth)acrylate and the like.

The content of the B block in the block copolymer is preferably, for example, 30% by mass or more and 70% by mass or less.

[B] The lower limit of the average molecular weight of the polymer is, for example, 3,000, preferably 6,000. On the other hand, the upper limit is, for example, 30,000, preferably 20,000.

A block copolymer can be synthesized by a conventionally known method. Moreover, a commercial item can also be used for a block copolymer and another [B] polymer. [B] The polymer may be a dispersant that coats at least part of the surface of the [A] inorganic compound in the composition.

[B] The lower limit of the content of the polymer is preferably 5 parts by mass, more preferably 10 parts by mass, and even more preferably 20 parts by mass with respect to 100 parts by mass of the [A] inorganic compound. On the other hand, the upper limit of this content is preferably 200 parts by mass, more preferably 100 parts by mass, and even more preferably 60 parts by mass.

([C] organic dye)
[C] The organic dye is a component that functions as an infrared shielding agent together with the [A] inorganic compound. By using [A] an inorganic compound and [C] an organic dye in combination, good visible light transmittance and infrared shielding properties can be exhibited. [C] The organic dye is dissolved in the [D] solvent.

[C] Organic dyes include organic dyes and organic pigments, and organic dyes are preferred. By using an organic dye, [D] the solubility in the solvent is increased, and the generation of agglomerated foreign matter can be further suppressed.

The solubility of the [C] organic dye in the [D] solvent at 20° C. and 0.1 MPa is 2% by mass or more. For this reason, the composition has high solubility of the [C] organic dye, improves dispersion stability and stability over time, and can provide an optical filter having good properties with few defects. The above-mentioned solubility refers to the concentration (% by mass) of the [C] organic dye in a solution in which the maximum amount of the [C] organic dye is dissolved in the [D] solvent, that is, in a saturated solution. When the [D] solvent is a mixed solvent, it is the concentration of the [C] organic dye in the saturated solution using the mixed solvent as a solvent. The solubility of the [C] organic dye can be achieved by combining the [C] organic dye and the [D] solvent. Although the upper limit of the solubility is not particularly limited, it may be, for example, 50% by mass.

[C] The organic dye preferably has a maximum absorption wavelength in the wavelength range of 600 nm or more and 1,000 nm or less. The lower limit of this maximum absorption wavelength is more preferably 650 nm. On the other hand, this upper limit is more preferably 900 nm, still more preferably 850 nm. By using the [C] organic dye having such a maximum absorption wavelength, it is possible to improve the visible light transmittance and infrared shielding properties of the resulting optical filter.

[C] As the organic dye, conventionally known organic dyes can be appropriately selected and used within a range that satisfies the above solubility. [C] Organic dyes include diiminium compounds, squarylium compounds, cyanine compounds, phthalocyanine compounds, naphthalocyanine compounds, quaterrylene compounds, aminium compounds, iminium compounds, azo compounds, anthraquinone compounds, porphyrin compounds, pyrrolopyrrole compounds, oxonol compounds, croconium A compound, a hexaphyrin compound, or a combination thereof can be used. [C] The organic dye preferably contains a phthalocyanine compound. Phthalocyanine compounds are excellent in color, heat resistance, light resistance, and the like.

[C] Organic dyes can be used singly or in combination of two or more. The composition preferably contains two or more [C] organic dyes. Furthermore, it may be more preferable to contain three or more [C] organic dyes. By using a combination of a plurality of [C] organic dyes, the obtained optical filter can have better visible light transmittance and infrared shielding properties. On the other hand, conventionally, when a plurality of types of organic dyes are used, the dispersion stability, the stability over time, and the like may deteriorate. However, according to the composition, even if a plurality of types of organic dyes are used, good dispersion stability and stability over time can be exhibited. The upper limit of the number of types of [C] organic dyes to be used is not particularly limited, and may be, for example, 10 types, 5 types, or 3 types.

The lower limit of the content of the [C] organic dye in the total solid content of the composition is preferably 0.1% by mass, more preferably 0.5% by mass, and even more preferably 1% by mass. On the other hand, the upper limit of this content is preferably 30% by mass, more preferably 15% by mass, and even more preferably 10% by mass. [C] By setting the content of the organic dye within the above range, the visible light transmittance and infrared shielding properties of the obtained optical filter are well balanced.

([D] solvent)
[D] The solvent is a component that functions as a dispersion medium for [A] the inorganic compound and dissolves [C] the organic pigment and the like.

The [D] solvent includes the [D1] solvent. [D1] The solvent has an SP value of 8.8 (cal/cm ³ ) ^1/2 or more and 12.0 (cal/cm ³ ) ^1/2 or less. The lower limit of the SP value is preferably 9.5 (cal/cm ³ ) ^1/2 . On the other hand, the upper limit is preferably 11.0 (cal/cm ³ ) ^1/2 , more preferably 10.5 (cal/cm ³ ) ^1/2 . By using the [D1] solvent having an SP value within such a specific range, the dispersibility of the [A] inorganic compound and the solubility of the [C] organic dye can be enhanced. Here, the SP value is the R.O. F. Fedors, Polym. Eng. Sci. , 14, 147 (1974).
Fedors formula:
SP value (δ)=(E _v /v) _1/2 =(ΣΔe _i /ΣΔv _i ) _1/2
E _v : Evaporation energy v: Molar volume Δe _i : Evaporation energy of atoms or atomic groups of each component Δv _i : Molar volume of each atom or atomic group

[D1] Examples of solvents include n-propanol (SP value: 11.8), 1,2,5,6-tetrahydrobenzyl alcohol (SP value: 11.3), diethylene glycol ethyl ether (SP value: 10.9 ), 3-methoxybutanol (SP value: 10.9), triacetin (SP value: 10.2), propylene glycol monomethyl ether (SP value: 10.2), cyclopentanone (SP value: 10.0), γ-butyrolactone (SP value: 9.9), cyclohexanone (SP value: 9.9), propylene glycol-n-propyl ether (SP value: 9.8), propylene glycol-n-butyl ether (SP value: 9. 7), dipropylene glycol methyl ether (SP value: 9.7), 1,4-butanediol diacetate (SP value: 9.6), 3-methoxybutyl acetate (SP value: 8.7), propylene glycol Diacetate (SP value: 9.6), ethyl lactate acetate (SP value: 9.6), ε-caprolactone (SP value: 9.6), 1,3-butylene glycol diacetate (SP value: 9.5 ), dipropylene glycol-n-propyl ether (SP value: 9.5), 1,6-hexanediol diacetate (SP value: 9.5), dipropylene glycol-n-butyl ether (SP value: 9.4 ), tripropylene glycol methyl ether (SP value: 9.4), tripropylene glycol-n-butyl ether (SP value: 9.3), cyclohexanol acetate (SP value: 9.2), diethylene glycol ethyl ether acetate (SP value: 9.0), ethylene glycol methyl ether acetate (SP value: 9.0), diethylene glycol monobutyl ether acetate (SP value: 8.9), ethylene glycol monobutyl ether acetate (SP value: 8.9), toluene ( SP value: 8.9), methyl acetate (SP value: 8.8), and the like. Note that the unit of the SP value ((cal/cm ³ ) ^1/2 ) is omitted as appropriate. [D1] Solvents can be used singly or in combination of two or more.

The lower limit of the content of the [D1] solvent relative to the entire composition is 40% by mass, preferably 50% by mass, more preferably 60% by mass, and even more preferably 65% by mass. By setting the content of the [D1] solvent to the above lower limit or more, the dispersibility of the [A] inorganic compound and the solubility of the [C] organic colorant are further enhanced. On the other hand, the upper limit of the content of the [D1] solvent is 90% by mass, preferably 80% by mass, more preferably 75% by mass. By setting the content of [D1] solvent to the above upper limit or less, a sufficient amount of other components can be blended, that is, by setting the content of [D1] solvent to the above range, the composition The dispersion stability and aging stability of the composition can be improved, and the composition can form an optical filter for a solid-state imaging device that has both good visible light transmission and infrared shielding properties with few defects.

The [D] solvent may contain a [D2] solvent other than the [D1] solvent. [D2] Solvents are solvents with an SP value of less than 8.8 (cal/cm ³ ) ^1/2 or greater than 12.0 (cal/cm ³ ) ^1/2 . [D2] Solvents include ( ^poly )alkylene glycol ^monoalkyl ether ^{, (} cyclo) Alkyl alcohols, keto alcohol (poly)alkylene glycol monoalkyl ether acetates, ketones, diacetates, carboxylic acid esters, lactams, aromatic hydrocarbons and the like can be mentioned. For example, the (poly)alkylene glycol monoalkyl ether having an SP value of less than 8.8 (cal/cm ³ ) ^1/2 includes propylene glycol monomethyl ether acetate (SP value: 8.7).

[D2] The SP value of the solvent is preferably less than 8.8 (cal/cm ³ ) ^1/2 . The lower limit of the SP value of the [D2] solvent is preferably 7 (cal/cm ³ ) ^1/2 , more preferably 8 (cal/cm ³ ) ^1/2 , and 8.5 (cal/cm ³ ). ^1/2 is more preferred.

The lower limit of the content of the [D1] solvent in the [D] solvent is preferably 50% by mass, more preferably 70% by mass, even more preferably 80% by mass, and even more preferably 90% by mass. The [D] solvent may consist essentially of the [D1] solvent. By setting the content of the [D1] solvent in the [D] solvent to the above lower limit or more, the dispersibility of the [A] inorganic compound and the solubility of the [C] organic dye are further increased, and the effect of the present invention is more sufficient. played in

[D] The solvent preferably contains a solvent having a cyclic structure. Solubility and dispersibility become better by using a solvent having a cyclic structure. The solvent having a cyclic structure may be the [D1] solvent or the [D2] solvent, but is preferably the [D1] solvent. The cyclic structure may be a carbocyclic ring or a heterocyclic ring. Moreover, the cyclic structure may be polycyclic or monocyclic. Moreover, the cyclic structure may be an aromatic ring or an alicyclic ring.

Preferred solvents having a cyclic structure include cyclic ketones, cyclic ethers, lactones (γ-butyrolactone, ε-caprolactone, etc.), lactams, aromatic hydrocarbons (toluene, etc.), and combinations thereof. Among these, cyclic ketones, lactones and aromatic hydrocarbons are preferred, and cyclic ketones and lactones are more preferred.

Examples of cyclic ketones include cyclobutanone, cyclopentanone, cyclohexanone, cycloheptanone, cyclooctanone and the like. Among these, cyclopentanone, cyclohexanone and cycloheptanone are preferred, and cyclopentanone and cyclohexanone are more preferred.

Examples of cyclic ethers include tetrahydrofuran and tetrahydropyran.

As the lactone, γ-butyrolactone, ε-caprolactone and the like can be mentioned, and γ-butyrolactone is preferred.

Examples of lactams include pentano-4-lactam, 5-methyl-2-pyrrolidinone, hexano-6-lactam, 6-hexanelactam and the like.

[D] The lower limit of the content of the solvent having a cyclic structure in the solvent is preferably 50% by mass, more preferably 70% by mass, still more preferably 80% by mass, and even more preferably 90% by mass. [D] The solvent may consist essentially of a solvent having a cyclic structure. [D] By setting the content of the solvent having a cyclic structure in the solvent to the above lower limit or more, the dispersibility of the [A] inorganic compound and the solubility of the [C] organic dye are further increased, and the effects of the present invention are further enhanced. played well.

The lower limit of the solid content concentration ([D] the total concentration of each component excluding the solvent) in the composition is preferably 5% by mass, more preferably 10% by mass. On the other hand, the upper limit of the solid content concentration is preferably 50% by mass, more preferably 40% by mass. By setting the solid content concentration within the above range, better dispersibility, stability, coatability and the like can be obtained.

([E] polymerizable compound)
When the composition contains [E] the polymerizable compound, it is possible to exhibit good curability and good heat resistance of the resulting optical filter. [E] A polymerizable compound refers to a compound having two or more polymerizable groups. Examples of polymerizable groups include ethylenically unsaturated groups, oxiranyl groups, oxetanyl groups, N-alkoxymethylamino groups and the like. [E] The polymerizable compound may be a polymer or a monomer, but is preferably a monomer. [E] The polymerizable compound is preferably a compound having two or more (meth)acryloyl groups, and a compound having two or more N-alkoxymethylamino groups, and has two or more (meth)acryloyl groups. Compounds are more preferred. [E] Polymerizable compounds can be used singly or in combination of two or more.

Compounds having two or more (meth)acryloyl groups include polyfunctional (meth)acrylates such as reaction products of aliphatic polyhydroxy compounds and (meth)acrylic acid, caprolactone-modified polyfunctional (meth)acrylates , alkylene oxide-modified polyfunctional (meth)acrylates, polyfunctional urethane (meth)acrylates such as reaction products of hydroxyl-containing (meth)acrylates and polyfunctional isocyanates, hydroxyl-containing (meth)acrylates and acid anhydrides and a polyfunctional (meth)acrylate having a carboxyl group, which is a reaction product with.

Examples of the aliphatic polyhydroxy compound include divalent aliphatic polyhydroxy compounds such as ethylene glycol, propylene glycol, polyethylene glycol, and polypropylene glycol; and glycerin, trimethylolpropane, pentaerythritol, dipentaerythritol, and the like. Trivalent or higher aliphatic polyhydroxy compounds can be mentioned. Examples of (meth)acrylates having a hydroxyl group include 2-hydroxyethyl (meth)acrylate, trimethylolpropane di(meth)acrylate, pentaerythritol tri(meth)acrylate, dipentaerythritol penta(meth)acrylate, and glycerol dimethacrylate. etc. can be mentioned. Examples of the polyfunctional isocyanate include tolylene diisocyanate, hexamethylene diisocyanate, diphenylmethylene diisocyanate, and isophorone diisocyanate. Examples of the acid anhydride include anhydrides of dibasic acids such as succinic anhydride, maleic anhydride, glutaric anhydride, itaconic anhydride, phthalic anhydride, hexahydrophthalic anhydride, pyromellitic anhydride, and biphenyltetracarboxylic acid. Tetrabasic acid dianhydrides such as acid dianhydrides and benzophenonetetracarboxylic acid dianhydrides can be mentioned.

Specific examples of compounds having two or more (meth)acryloyl groups include ω-carboxypolycaprolactone mono(meth)acrylate, ethylene glycol (meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1 , 9-nonanediol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, bisphenoxyethanol fluorene di(meth)acrylate, dimethyloltricyclode Kandi (meth)acrylate, 2-hydroxy-3-(meth)acryloyloxypropyl methacrylate, 2-(2'-vinyloxyethoxy)ethyl (meth)acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol tri( meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, tri(2-(meth)acryloyloxyethyl)phosphate, ethylene oxide-modified dipenta Erythritol hexaacrylate, succinic acid-modified pentaerythritol triacrylate, urethane (meth)acrylate compounds and the like can be mentioned.

Among compounds having two or more (meth)acryloyl groups, polyfunctional (meth)acrylates are preferred, and polyfunctional (meth)acrylates having 3 or more and 10 or less (meth)acryloyl groups are more preferred. Specifically, trimethylolpropane triacrylate, pentaerythritol triacrylate, dipentaerythritol pentaacrylate, and dipentaerythritol hexaacrylate are preferred.

Examples of compounds having two or more N-alkoxymethylamino groups include compounds having a melamine structure, benzoguanamine structure, and urea structure. Specific examples of compounds having two or more N-alkoxymethylamino groups include N,N,N',N',N'',N''-hexa(alkoxymethyl)melamine, N,N,N' , N′-tetra(alkoxymethyl)benzoguanamine, N,N,N′,N′-tetra(alkoxymethyl)glycoluril and the like.

The lower limit of the content of the [E] polymerizable compound in the total solid content of the composition is preferably 5 parts by mass, more preferably 10 parts by mass, and even more preferably 20 parts by mass. On the other hand, the upper limit of this content is preferably 60% by mass, more preferably 50% by mass.

([F] polymerization initiator)
[F] The polymerization initiator is a component that initiates the polymerization reaction of the [E] polymerizable compound. [F] Polymerization initiators include photopolymerization initiators, thermal polymerization initiators, and the like, but photopolymerization initiators are preferred. Thereby, photosensitivity (radiation sensitivity) can be imparted to the composition. The photopolymerization initiator is a compound that generates active species capable of initiating polymerization of the [E] polymerizable compound upon exposure to radiation such as visible light, ultraviolet light, deep ultraviolet light, electron beams, and X-rays. [F] The polymerization initiator can be used singly or in combination of two or more.

[F] Examples of polymerization initiators include thioxanthone-based compounds, acetophenone-based compounds, biimidazole-based compounds, triazine-based compounds, O-acyloxime-based compounds, onium salt-based compounds, benzoin-based compounds, benzophenone-based compounds, and α-diketones. compounds, polynuclear quinone-based compounds, diazo-based compounds, imidosulfonate-based compounds, onium salt-based compounds, and the like. Among these, thioxanthone-based compounds, acetophenone-based compounds, biimidazole-based compounds, triazine-based compounds and O-acyloxime-based compounds are preferred, and O-acyloxime-based compounds are more preferred.

Thioxanthone compounds include thioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone, 2-isopropylthioxanthone, 4-isopropylthioxanthone, 2,4-dichlorothioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, 2 , 4-diisopropylthioxanthone and the like.

Acetophenone compounds include 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)butane -1-one, 2-(4-methylbenzyl)-2-(dimethylamino)-1-(4-morpholinophenyl)butan-1-one and the like.

Biimidazole compounds include 2,2′-bis(2-chlorophenyl)-4,4′,5,5′-tetraphenyl-1,2′-biimidazole, 2,2′-bis(2,4 -dichlorophenyl)-4,4',5,5'-tetraphenyl-1,2'-biimidazole, 2,2'-bis(2,4,6-trichlorophenyl)-4,4',5,5 '-Tetraphenyl-1,2'-biimidazole and the like can be mentioned.

When a biimidazole-based compound is used, it is preferable to use a hydrogen donor in combination, because the sensitivity can be improved. The term "hydrogen donor" as used herein means a compound capable of donating a hydrogen atom to a radical generated from a biimidazole compound upon exposure. Examples of hydrogen donors include mercaptan hydrogen donors such as 2-mercaptobenzothiazole and 2-mercaptobenzoxazole; 4,4′-bis(dimethylamino)benzophenone and 4,4′-bis(diethylamino)benzophenone Amine-based hydrogen donors can be mentioned.

Examples of triazine-based compounds include compounds described in paragraphs [0063] to [0065] of JP-B-57-6096 and JP-A-2003-238898.

Examples of O-acyloxime compounds include 1,2-octanedione-1-[4-(phenylthio)phenyl]-2-(O-benzoyloxime), ethanone-1-[9-ethyl-6-(2- methylbenzoyl)-9H-carbazol-3-yl]-1-(O-acetyloxime), ethanone-1-[9-ethyl-6-(2-methyl-4-tetrahydrofuranylmethoxybenzoyl)-9H-carbazole- 3-yl]-1-(O-acetyloxime), ethanone-1-[9-ethyl-6-{2-methyl-4-(2,2-dimethyl-1,3-dioxolanyl)methoxybenzoyl}-9H -carbazol-3-yl]-1-(O-acetyloxime) and the like. Commercially available O-acyloxime compounds include NCI-831, NCI-930 (manufactured by ADEKA Corporation), OXE-03, OXE-04 (manufactured by BASF) and the like. can.

When using a photoinitiator, a sensitizer can also be used together. Examples of such sensitizers include 4,4'-bis(dimethylamino)benzophenone, 4,4'-bis(diethylamino)benzophenone, 4-diethylaminoacetophenone, 4-dimethylaminopropiophenone, 4-dimethylamino Ethyl benzoate, 2-ethylhexyl 4-dimethylaminobenzoate, 2,5-bis(4-diethylaminobenzal) cyclohexanone, 7-diethylamino-3-(4-diethylaminobenzoyl) coumarin, 4-(diethylamino) chalcone, etc. can be mentioned.

[F] The lower limit of the content of the polymerization initiator is preferably 1 part by mass, more preferably 5 parts by mass, per 100 parts by mass of the [E] polymerizable compound. On the other hand, the upper limit of this content is preferably 100 parts by mass, more preferably 40 parts by mass.

(binder resin)
The composition may further contain a binder resin. The [B] polymer is not included in the binder resin. Although the binder resin is not particularly limited, it is preferably a resin having an acidic functional group such as a carboxyl group or a phenolic hydroxyl group. Among them, a polymer having a carboxy group (hereinafter also referred to as a "carboxy group-containing polymer") is preferable. As the carboxy group-containing polymer, for example, an ethylenically unsaturated monomer having one or more carboxy groups (hereinafter also referred to as "unsaturated monomer (1)") and other copolymerizable ethylene and a copolymer with a polyunsaturated monomer (hereinafter also referred to as "unsaturated monomer (2)").

Examples of the unsaturated monomer (1) include (meth)acrylic acid, maleic acid, maleic anhydride, monosuccinic acid [2-(meth)acryloyloxyethyl], ω-carboxypolycaprolactone mono(meth) Acrylate, p-vinylbenzoic acid and the like can be mentioned.

Examples of the unsaturated monomer (2) include N-substituted maleimides such as N-phenylmaleimide and N-cyclohexylmaleimide;
aromatic vinyl compounds such as styrene, α-methylstyrene, p-hydroxystyrene, p-hydroxy-α-methylstyrene, p-vinylbenzyl glycidyl ether, acenaphthylene;
Methyl (meth) acrylate, n-butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, allyl (meth) acrylate, benzyl (meth) acrylate, polyethylene glycol (polymerization degree 2- 10) Methyl ether (meth) acrylate, polypropylene glycol (degree of polymerization 2-10) methyl ether (meth) acrylate, polyethylene glycol (degree of polymerization 2-10) mono (meth) acrylate, polypropylene glycol (degree of polymerization 2-10) mono (meth)acrylate, cyclohexyl (meth)acrylate, isobornyl (meth)acrylate, tricyclo[5.2.1.0 ^2,6 ]decan-8-yl (meth)acrylate, dicyclopentenyl (meth)acrylate, glycerol mono (meth) acrylate, 4-hydroxyphenyl (meth) acrylate, ethylene oxide-modified paracumylphenol (meth) acrylate, glycidyl (meth) acrylate, 3,4-epoxycyclohexylmethyl (meth) acrylate, 3-[(meth) (meth)acrylic acid esters such as acryloyloxymethyl]oxetane, 3-[(meth)acryloyloxymethyl]-3-ethyloxetane,
Vinyl ethers such as cyclohexyl vinyl ether, isobornyl vinyl ether, tricyclo[5.2.1.0 ^2,6 ]decan-8-yl vinyl ether, pentacyclopentadecanyl vinyl ether, 3-(vinyloxymethyl)-3-ethyloxetane ,
Examples include macromonomers having a mono(meth)acryloyl group at the end of a polymer molecular chain such as polystyrene, polymethyl(meth)acrylate, poly-n-butyl(meth)acrylate, and polysiloxane.

As the binder resin, a carboxyl group-containing polymer having a polymerizable unsaturated bond such as a (meth)acryloyl group in the side chain can also be used. Polysiloxane or the like can also be used as the binder resin.

(Additive)
The composition can also contain various additives as needed.

Examples of additives include surfactants, adhesion promoters, antioxidants, ultraviolet absorbers, aggregation inhibitors, residue improvers, and developability improvers.

Examples of surfactants include fluorine surfactants and silicone surfactants. The content of the surfactant in the total solid content of the composition can be, for example, 0.01% by mass or more and 5% by mass or less.

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

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-tetraoxa-spiro[5.5]undecane, thiodiethylenebis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate] and the like. The antioxidant content of the total solid content in the composition may be, for example, 0.01% by mass or more and 5% by mass or less.

Examples of UV absorbers include 2-(3-t-butyl-5-methyl-2-hydroxyphenyl)-5-chlorobenzotriazole and alkoxybenzophenones.

Examples of the aggregation inhibitor include sodium polyacrylate and the like.

Examples of residue improvers 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, 4-amino-1,2-butanediol and the like can be mentioned.

Developability improving agents include mono[2-(meth)acryloyloxyethyl] succinate, mono[2-(meth)acryloyloxyethyl] phthalate, ω-carboxypolycaprolactone mono(meth)acrylate, etc. can be mentioned.

(Preparation method)
The method for preparing the composition is not particularly limited, and the composition can be prepared by mixing each component. For example, first, a dispersion containing [A] an inorganic compound, [B] a polymer and [D] a solvent is prepared, and [C] an organic dye and other components are added to this dispersion and mixed. can do. At this time, the [D] solvent may be added. The dispersion or the composition can be filtered to remove aggregates, if necessary.

<Method for Forming Infrared Shielding Film for Solid-State Image Sensor>
A method for forming an infrared shielding film for a solid-state imaging device according to an embodiment of the present invention comprises:
Step of forming a coating film on one side of the substrate (Step 1)
with
The coating film is formed from the composition for a solid-state imaging device.

The forming method is
A step of irradiating at least part of the coating film with radiation (step 2), and a step of developing the coating film after irradiation (step 3).
is preferably further provided.

According to this forming method, by using a composition having high dispersion stability and long-term stability, it is possible to form an optical filter for a solid-state imaging device that has few defects and has both good visible light transmittance and infrared shielding properties. can be done. Moreover, when the said formation method is provided with the process 2 and the process 3, it has favorable patterning property.

(Step 1)
In step 1, the composition is used to form a coating film on one side of a substrate (support). Examples of the substrate include glass substrates and synthetic resin substrates. Note that the shape of the substrate is not limited to a plate shape. When an infrared shielding film is incorporated into a solid-state imaging device, which will be described later, the transparent substrate, microlenses, color filters, and the like, which are components of the solid-state imaging device, correspond to the substrate.

Formation of the coating film can usually be carried out by applying the composition. Appropriate coating methods such as a spray method, a roll coating method, a spin coating method (spin coating method), a slit die coating method (slit coating method), and a bar coating method can be employed for the coating.

After coating, pre-baking is performed to evaporate the solvent, thereby forming a coating film. The conditions for heat drying in the prebaking are, for example, 70° C. or higher and 110° C. or lower and about 1 minute or longer and 10 minutes or shorter.

(Step 2)
In step 2, at least part of the coating film is irradiated with radiation. Examples of the radiation source used for exposing the coating film include lamp light sources 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, argon ion lasers, YAG lasers, Laser light sources such as XeCl excimer lasers and nitrogen lasers can be used. An ultraviolet LED can also be used as an exposure light source. Radiation having a wavelength in the range of 190 nm or more and 450 nm or less is preferable. The exposure dose of radiation is generally about 10 J/m ² or more and 50,000 J/m ² or less.

(Step 3)
In step 3, the coating film after irradiation is developed. As the developer, an alkali developer or an organic solvent developer is generally used. After development, the film is usually washed with water.

Examples of alkaline developers include sodium carbonate, sodium hydrogen carbonate, sodium hydroxide, potassium hydroxide, tetramethylammonium hydroxide (TMAH), choline, 1,8-diazabicyclo-[5.4.0]-7-undecene. , 1,5-diazabicyclo-[4.3.0]-5-nonene and the like are preferred. An appropriate amount of a water-soluble organic solvent such as methanol or ethanol, a surfactant, or the like can be added to the alkaline developer.

Examples of organic solvent developers include acetone, methyl ethyl ketone, 2-octanone, 2-nonanone, 2-heptanone, 3-heptanone, 4-heptanone, 2-hexanone, 3-hexanone, diisobutyl ketone, methylcyclohexanone, acetophenone, and methylacetophenone. Ketones, propyl acetate, butyl acetate, isobutyl acetate, amyl acetate, butenyl acetate, isoamyl acetate, propyl formate, butyl formate, isobutyl formate, amyl formate, isoamyl formate, methyl valerate, methyl pentenoate, methyl crotonate, crotonic acid Ethyl, methyl propionate, ethyl propionate, ethyl 3-ethoxypropionate, methyl lactate, ethyl lactate, propyl lactate, butyl lactate, isobutyl lactate, amyl lactate, isoamyl lactate, methyl 2-hydroxyisobutyrate, 2-hydroxyisobutyric acid Esters such as ethyl, methyl benzoate, ethyl benzoate, phenyl acetate, benzyl acetate, methyl phenylacetate, benzyl formate, phenylethyl formate, methyl 3-phenylpropionate, benzyl propionate, ethyl phenylacetate, 2-phenylethyl acetate, etc. can be preferably used.

As a development processing method, a shower development method, a spray development method, a dip (immersion) development method, a puddle (liquid puddle) development method, or the like can be applied. The developing conditions are normal temperature and about 5 seconds to 300 seconds.

By the above development, the non-exposed areas of the coating film are dissolved and removed. Thereafter, post-baking is performed as necessary to obtain an infrared shielding film patterned into a predetermined shape. The post-baking conditions are generally 180° C. or higher and 280° C. or lower and about 1 minute or longer and 60 minutes or shorter.

When the composition does not contain [E] a polymerizable compound and [F] a polymerization initiator, unlike the above-described forming method, curing treatment such as exposure may not be performed. In addition, development processing may not be performed, and in this case, an infrared shielding film that is not patterned can be formed.

The lower limit of the average film thickness of the infrared shielding film for a solid-state imaging device thus formed is usually 0.5 μm, preferably 1 μm. On the other hand, the upper limit of this average film thickness is usually 5 μm, preferably 3 μm. When the average film thickness of the infrared shielding film is within the above range, the balance between the visible light transmittance and the infrared shielding property becomes better.

The infrared shielding film is preferably incorporated in the solid-state imaging device as one component. In this case, the infrared shielding film alone functions as an optical filter (infrared cut filter). Incorporation of the infrared shielding film in the solid-state imaging device is preferable because a large process margin can be obtained. When the infrared shielding film is incorporated in the solid-state imaging device, the infrared shielding film is arranged, for example, on the outer surface side of the microlens of the solid-state imaging device, between the microlens and the color filter, between the color filter and the photodiode, and the like. can do. The infrared shielding film is preferably laminated between the microlens and the color filter or between the color filter and the photodiode.

The optical filter may be formed by laminating an infrared shielding film on the surface of a transparent substrate. As the transparent substrate, glass, transparent resin, or the like is adopted. Examples of the transparent resin include polycarbonate, polyester, aromatic polyamide, polyamideimide, and polyimide. Such an optical filter is also suitably used as an infrared cut filter in a solid-state imaging device.

Solid-state imaging devices equipped with an infrared shielding film (optical filter) are used in digital still cameras, mobile phone cameras, digital video cameras, PC cameras, surveillance cameras, automobile cameras, personal digital assistants, personal computers, video games, medical equipment, etc. Useful.

EXAMPLES The present invention will be specifically described below based on Examples, but the present invention is not limited to these Examples. The properties of the polymers obtained in Synthesis Examples were measured by the following methods.

[Weight average molecular weight (Mw), number average molecular weight (Mn) and dispersity (Mw/Mn)]
The Mw and Mn of the polymer were measured by gel permeation chromatography (GPC) using Tosoh GPC columns (2 G2000HXL, 1 G3000HXL, 1 G4000HXL) under the following analysis conditions.
The degree of dispersion (Mw/Mn) was calculated from the measurement results of Mw and Mn.
(Analysis conditions)
Elution solvent: Tetrahydrofuran Flow rate: 1.0 mL/min Sample concentration: 1.0% by mass
Sample injection volume: 100 μL
Column temperature: 40°C
Detector: Differential refractometer Standard substance: Monodisperse polystyrene

<Synthesis Example 1> (Synthesis of organic dye (C-1))
An organic dye (C-1), which is a phthalocyanine compound represented by the following formula, was synthesized using the method described in paragraphs [0020] to [0025] (Example 1) of JP-A-05-25177.

<Synthesis Example 2> (Synthesis of organic dye (C-2))
An organic dye (C-2), which is a phthalocyanine compound represented by the following formula, was synthesized using the method described in paragraph [0075] (Example 4) of JP-A-2016-204536.

<Synthesis Example 3> (Synthesis of organic dye (C-3))
An organic dye (C-3), which is a squarylium compound represented by the following formula, was synthesized using the method described in JP-A-1-228960.

<Synthesis Example 4> (Synthesis of organic dye (C-4))
An organic dye (C-4), which is a phthalocyanine compound represented by the following formula, was synthesized using the method described in JP-A-2-138382.

Other organic dyes used are as follows.
・ Organic dye (C-5): Yamada Chemical Industry Co., Ltd. "FDN-002" (phthalocyanine compound)
・ Organic dye (C-6): Yamada Chemical Industry Co., Ltd. "FDR-004" (phthalocyanine compound)
・ Organic dye (C-7): Yamada Chemical Industry Co., Ltd. "FDN-001" (phthalocyanine compound)

<Synthesis Examples 5-7> (Synthesis of Polymers (B-1) to (B-3))
Using the method described in the literature (Macromolecules 1992, 25, p5907-5913), the polymers (B-1) to (B-3) having the monomer composition ratios (mass ratios) described in Table 1 below were synthesized. Ta. A polymer having a diblock structure was obtained, which was composed of a block of a monomer (DAMA) having an adsorptive group for an inorganic compound as a pigment and blocks of other components. The solution after the reaction was quenched with methanol, and the obtained reaction solution was washed with a 7% by mass sodium hydrogen carbonate aqueous solution and then with water. Thereafter, propylene glycol monomethyl ether acetate (PGMEA) was subjected to solvent replacement to obtain polymer solutions shown in Table 1 below with a yield of 80 to 82% by mass. Table 1 shows the amine value, Mw, Mw/Mn and solid content of each polymer obtained. In the table, DAMA is dimethylaminoethyl methacrylate, EHMA is 2-ethylhexyl methacrylate, nBMA is normal butyl methacrylate, and PME-200 (“Blemmer” manufactured by NOF Corporation) is methoxypolyethylene glycol monomethacrylate. Specifically, PME-200 is a polymer of monomers represented by CH ₂ ═C(CH ₃ )COO(C ₂ H ₄ O) _n —CH ₃ (n≈4).

<Synthesis Example 8> (Synthesis of polymer (B-8))
A polymer (B-8) having a monomer composition ratio (mass ratio) shown in Table 1 below was synthesized in the same manner as in Synthesis Examples 5 to 7, except that all the monomers were polymerized at once. Ta. Polymer (B-8) is a random copolymer.

<Synthesis Example 9> (Synthesis of Cesium Tungsten Oxide Powder)
A cesium tungsten oxide (Cs _0.33 WO ₃ ) powder was synthesized using the method described in paragraph [0113] of Japanese Patent No. 4096205 .

The polymers and solvents used in Preparation Examples, Examples and Comparative Examples are shown below.
(Polymer)
· B-1 to B-3: Polymers (B-1) to (B-3) in Table 1 synthesized in Synthesis Examples 5 to 7 above
・ B-4: "BYK-LPN6919" from BYK Chemie (solid content concentration 61% by mass, amine value 120 mgKOH / g)
・ B-5: "BYK-2001" from BYK Chemie (solid content concentration 46% by mass, amine value 29 mgKOH / g)
・ B-6: “BYK-2000” from BYK Chemie (solid content concentration 40% by mass, amine value 4 mgKOH / g)
・ B-7: "BYK-LPN22102" from BYK Chemie (solid content concentration 38.5% by mass, amine value 23 mgKOH / g)
· B-8: Polymer (B-8) in Table 1 synthesized in Synthesis Example 8 above

(solvent)
CPN: cyclopentanone (SP value: 10.0)
CHN: cyclohexanone (SP value: 9.9)
GBL: γ-butyrolactam (SP value: 9.9)
Tol: toluene (SP value: 8.9)
PGMEA: propylene glycol monomethyl ether acetate (SP value: 8.7)

[Preparation Example 1] (Preparation of dispersion (X-1))
25.00 parts by mass of the above cesium tungsten oxide, 13.11 parts by mass of polymer (B-4), and 61.89 parts by mass of cyclopentanone (CPN) as a solvent (dispersion medium) were prepared. These were filled in a container together with 2000 parts by mass of zirconia beads having a diameter of 0.1 mm, and dispersed with a paint shaker to obtain dispersion liquid (X-1) having an average particle diameter (D50) of 19 nm. The average particle size was measured by the DLS method using a light scattering measurement device (“ALV-5000” manufactured by ALV, Germany).

[Preparation Examples 2 to 15] (Preparation of dispersions (X-2) to (X-15))
Dispersions (X-2) to (X-15) were obtained in the same manner as in Preparation Example 1 except that each component shown in Table 2 was used. Table 2 also shows the average particle size (D50) of the particles in the obtained dispersion. CsWO in Table 2 indicates the cesium tungsten oxide obtained in Synthesis Example 9.

[Example 1]
50.00 parts by mass of the dispersion liquid (X-1), 0.75 parts by mass of the organic dye (C-1), and "KAYARAD DPHA" (dipentaerythritol hexaacrylate and dipentaerythritol hexaacrylate from Nippon Kayaku Co., Ltd.) as a polymerizable compound Pentaacrylate mixture) 6.26 parts by mass, ADEKA's "NCI-930" (O-acyl oxime compound) 1.46 parts by mass as a polymerization initiator, Neos Co.'s "FTX-218D" as a surfactant ( Fluorinated surfactant) 0.02 parts by weight, BASF's "Irganox 1010" (phenolic antioxidant) 0.01 parts by weight as an antioxidant, and 41.50 parts by weight of cyclopentanone (CNP) as an additional solvent Parts were weighed into a container and mixed with a stirrer. 200 mL of this mixture was filtered under pressure at 0.5 MPa for 3 minutes using a 0.5 μm PTFE (polytetrafluoroethylene) filter to obtain the composition (Z-1) of Example 1. The solubility of the organic dye (C-1) in the solvent (CPN) at 20° C. and 0.1 MPa was 2% by mass or more.
Here, the solubility was obtained by the following method. First, an organic dye was added to the solvent (the amount added at this time was an amount corresponding to 10% by mass of the entire solution), the resulting solution was heated to 50°C, and then cooled to room temperature (20°C). and left for 12 hours. Based on the amount of each organic dye remaining undissolved after standing, the solubility (20° C.) of each dye in the solvent was calculated.

[Examples 2 to 23, Comparative Examples 1 to 13]
Each composition (Z-2) to (Z- 23), (Y-1) to (Y-13) were obtained. Tables 3 to 7 also show the solubility of the organic dyes used in the solvents used. Each composition also contains a solvent derived from the polymer solution. The values in the table are values in consideration of these factors.

[evaluation]
The following evaluation was performed using each obtained composition. The evaluation results are shown in Tables 3-7.

(dispersion stability)
200 mL of each composition was pressure filtered at 0.5 MPa for 3 minutes using a 0.5 μm polytetrafluoroethylene (PTFE) filter. Based on the recovery rate of the filtrate at this time, the dispersion stability (filtration property, precipitation suppressing property) was evaluated according to the following criteria. In the case of A or B, the dispersion stability was good, and in the case of A, it was evaluated as particularly excellent. If a large amount of agglomerate or the like is collected and the recovery rate is less than 90% (C), the filtration becomes insufficient, resulting in a significant drop in productivity.
A: 95% or more B: 90% or more and less than 95% C: less than 90%

The following evaluations were carried out using the composition after filtration.

Each composition was applied on a glass substrate by a spin coating method so as to have a predetermined film thickness. After that, the coating film was heated at 100° C. for 120 seconds and exposed to 1000 mJ/cm ² with an i-line stepper. Then, by heating at 220° C. for 300 seconds, an infrared shielding film having an average film thickness of 1.40 to 1.60 μm was formed on the glass substrate. Each average film thickness is shown in Tables 3-7. The film thickness was measured with a stylus profilometer (“Alpha Step IQ” manufactured by Yamato Kagaku Co., Ltd.). Next, the transmittance in each wavelength region of the infrared shielding film produced on the glass substrate was measured in comparison with the glass substrate using a spectrophotometer (“V-7300” manufactured by JASCO Corporation). Based on the obtained spectrum, evaluation was performed according to the following evaluation criteria.

(visible light transmittance)
The average transmittance of visible light with a wavelength of 450-550 nm was calculated. When the average transmittance is less than 70%, the sensitivity of the solid-state imaging device when used as an infrared shielding film is lowered. Moreover, the average transmittance was evaluated according to the following criteria.
A: 80% or more B: 70% or more and less than 80% C: less than 70%

(Infrared shielding property 1)
The average transmittance of infrared rays with a wavelength of 700-900 nm was calculated. If the average transmittance is 20% or more, the amount of noise in the solid-state imaging device increases when used as an infrared shielding film. Moreover, the average transmittance was evaluated according to the following criteria.
A: Less than 15% B: 15% or more and less than 20% C: 20% or more

(Infrared shielding property 2)
With respect to the transmittance of infrared rays with a wavelength of 1200 nm, it can be said that the transmittance is less than 15% and exhibits practically good infrared shielding properties. The transmittance at a wavelength of 1200 nm was evaluated according to the following criteria.
A: Less than 10% B: 10% or more and less than 15% C: 15% or more

(S/N ratio)
The ratio (S/N ratio) of the average transmittance (S) in the visible light region (450-550 nm) and the average transmittance (N) in the infrared region (700-900 nm) was taken to estimate the practical performance. The higher the S/N ratio, the better the performance, and it was judged that a value of 5 or more was usable at a practical level. The S/N ratio was evaluated according to the following criteria.
A: 5 or more B: less than 5

(defect suppression)
A cured film having a thickness of 1 μm was formed by the same method as in paragraph [0139]. The defect density of the cured film was measured using a defect/foreign matter inspection device (KLA-Tencor "KLA 2351"). It can be judged that the smaller the value of this defect density, the higher the defect suppressing property. A defect means a detection point having a size of 1 μm or more. Based on the above defect density, the defect suppression property was evaluated according to the following criteria.
A: 10/cm ² or less B: More than 10/cm ² or less than 50/cm ² C: More than 50/cm ²

(Stability over time: Thickening rate)
The composition was stored at 40°C for 3 days, and the viscosity before and after storage was measured. The viscosity was measured using an E-type viscometer (E-type viscometer RE-80L manufactured by Toki Sangyo Co., Ltd.) while the coating solution was kept at 20°C. When the viscosity before storage was V1 and the viscosity after storage was V2, the value of (|V2−V1|/V1)×100 was defined as the viscosity increase rate (%). Based on this viscosity increase rate, evaluation was made according to the following criteria. The lower the numerical value of the viscosity increase rate, the better it was.
A: Less than 5% B: 5% or more and less than 10% C: 10% or more

(Stability over time: number of defects)
The composition was stored at 40° C. for 3 days, and the number of defects was measured using the stored composition. The measurement method and criteria were the same as those for the evaluation of "defect suppression".

(patternability)
For compositions Z-1 to Z-13, Z-17 to Z-18, Z-23, Y-1 to Y-8 and Y-10, a coating film having a thickness of 1 μm was coated with silicon using a spin coating method. formed on the substrate. After heating at 100° C. for 120 seconds, exposure was performed at 1000 mJ/cm ² with an i-line stepper through a mask having an L/S pattern of 50 μm. The exposed substrate was immersed in acetone and developed to remove the non-exposed area. Then, by heating at 220° C. for 300 seconds, an infrared shielding film having an L/S pattern was produced. Observation with an optical microscope confirmed that an L/S pattern with a line width of 50 μm was formed.

For compositions Z-14 to Z-16, Z-19 to Z-22 and Y-9, infrared shielding films were produced in the same manner except that the developer was changed to a 2.38% TMAH solution. Observation with an optical microscope confirmed that an L/S pattern of 50 μm was formed.

As shown in Tables 3 to 7, the compositions Z-1 to Z-23 of Examples 1 to 23 have high dispersion stability and long-term stability, and also have good patterning properties. In addition, it can be seen that the infrared shielding films (optical filters) obtained from these compositions have few defects and have both good visible light transmittance and infrared shielding properties.

The composition for a solid-state imaging device of the present invention can be suitably used as a material for forming an optical filter, more specifically an infrared filter, for a solid-state imaging device.

Claims (9)

In a composition for a solid-state imaging device containing an inorganic compound, a polymer, an organic dye and a solvent,
The amine value of the polymer is 130 mgKOH/g or more and 200 mgKOH/g or less,
The solvent contains a specific solvent having a solubility parameter of 8.8 (cal/cm ³ ) ^1/2 or more and 12.0 (cal/cm ³ ) ^1/2 or less,
The content of the specific solvent with respect to the entire composition for a solid-state imaging device is 40% by mass or more and 90% by mass or less,
The solubility of the organic dye in the solvent at 20° C. and 0.1 MPa is 2% by mass or more,
The solvent contains a solvent having a cyclic structure,
The content of the solvent having the cyclic structure in the solvent is 50% by mass or more,
The solvent having the cyclic structure is a cyclic ketone,
The polymer is a block copolymer having a block having a functional group containing a nitrogen atom and a block having solvent affinity,
A composition for a solid-state imaging device, wherein the inorganic compound is cesium tungsten oxide . 2. The composition for a solid-state imaging device according to claim 1, having a solid content concentration of 5% by mass or more and 50% by mass or less. 3. The composition for a solid-state imaging device according to claim 1, wherein the content of the inorganic compound in the total solid content is 1% by mass or more and 70% by mass or less. 4. The composition for a solid-state imaging device according to claim 1, comprising two or more of the above organic dyes. 5. The composition for a solid-state imaging device according to any one of claims 1 to 4 , wherein the organic dye has a maximum absorption wavelength in a wavelength range of 600 nm or more and 1,000 nm or less. The above organic dyes include diiminium compounds, squarylium compounds, cyanine compounds, phthalocyanine compounds, naphthalocyanine compounds, quaterrylene compounds, aminium compounds, iminium compounds, azo compounds, anthraquinone compounds, porphyrin compounds, pyrrolopyrrole compounds, oxonol compounds, croconium compounds, hexa 6. The composition for a solid-state imaging device according to any one of claims 1 to 5 , which is a filin compound or a combination thereof. 7. The composition for a solid-state imaging device according to claim 1 , further comprising a polymerizable compound. A step of forming a coating film on one surface side of the substrate,
A method for forming an infrared shielding film for a solid-state imaging device, wherein the coating film is formed from the composition for a solid-state imaging device according to any one of claims 1 to 7 . The method of forming an infrared shielding film for a solid-state imaging device according to claim 8 , further comprising: irradiating at least part of the coating film with radiation; and developing the coating film after the radiation irradiation.