TWI751314B - Composition for solid-state imaging element and method for forming infrared shielding film for solid-state imaging element - Google Patents

Abstract

The present invention is a composition for a solid-state imaging element, comprising 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, and the solvent includes a solubility parameter It is a specific solvent of 8.8 or more and 12.0 or less, and the content of the specific solvent is 40 mass % or more and 90 mass % or less with respect to the whole composition for a solid-state imaging element, in the solvent at 20° C. and 0.1 MPa The solubility of the organic dye is 2% by mass or more.

Description

Composition for solid-state imaging element and method for forming infrared shielding film for solid-state imaging element

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

A charge-coupled device (CCD) image sensor or a complementary metal oxide semiconductor (CMOS) image sensor, etc. is mounted in a video camera, a digital camera, a mobile phone with a camera function, etc. Solid-state imaging element. The sensitivity of the photodiodes included in these solid-state imaging elements spans the visible light region to the infrared region. Therefore, in the solid-state imaging element, a filter for blocking infrared rays is provided. With the infrared blocking filter, the sensitivity of the solid-state imaging element can be corrected so as to be close to human visual acuity.

The infrared blocking filter contains an organic dye or an inorganic compound as an infrared blocking agent (see Japanese Patent Laid-Open No. 2013-137337 and Japanese Patent Laid-Open No. 2013-151675). The infrared shielding filter can generally be formed by coating a composition containing an infrared shielding agent on a substrate. In the infrared shielding filter, the coating film of the composition functions as a film that shields infrared rays.

[Prior Art Literature]

[Patent Literature]

Patent Document 1: Japanese Patent Laid-Open No. 2013-137337

Patent Document 2: Japanese Patent Laid-Open No. 2013-151675

The composition for solid-state imaging elements is required to form an optical filter having both good visible light transmittance and infrared shielding properties. In addition, the composition for solid-state imaging elements is required to have high dispersion stability or stability over time. When these are insufficient, a defect of the optical filter (infrared shielding film) obtained, or the fall of productivity may arise. In addition, visible light transmittance and infrared shielding properties are also affected. Furthermore, a coating film may be exposed and developed to form a patterned infrared shielding film, but in this case, the composition for solid-state imaging elements to be used is required to have good patterning properties.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a composition for a solid-state imaging element and a method for forming a shielding film for a solid-state imaging element using the composition for a solid-state imaging element, the composition for a solid-state imaging element It is possible to form an optical filter for a solid-state imaging device that has high dispersion stability and stability over time, has few defects, and has both good visible light transmittance and infrared shielding properties.

The invention made in order to solve the above-mentioned problem is a composition for a solid-state imaging element, which comprises 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 content of the specific solvent with respect to the entire solid-state imaging element composition It is 40 mass % or more and 90 mass % or less, and the solubility of the said organic dye in the said solvent at 20 degreeC and 0.1 MPa is 2 mass % or more.

Another invention accomplished in order to solve the above-mentioned problem is a method for forming an infrared shielding film for a solid-state imaging element, which includes the step of forming a coating film on one surface side of a substrate, and which is formed from the composition for a solid-state imaging element. the coating film.

According to the present invention, it is possible to provide a composition for a solid-state imaging element, and a method for forming a shielding film for a solid-state imaging element using the composition for a solid-state imaging element, which is capable of forming dispersion stability and stability over time. An optical filter for solid-state imaging devices with high stability, few defects, and good visible light transmittance and infrared shielding properties.

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

<Composition for solid-state imaging element>

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

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

The composition preferably further contains [E] a polymerizable compound, and in addition to that, preferably contains [F] a polymerization initiator. The composition may further contain other ingredients. Hereinafter, each component will be described in detail.

([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 an absorption maximum wavelength in a range of wavelength 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 a semimetal (silicon or the like). As the [A] inorganic compound, specifically, cesium tungsten oxide, quartz, Magnetite, alumina, titania, zirconia, spinel or combinations of these. These inorganic compounds may be used alone or in combination of two or more.

As the [A] inorganic compound, among these, cesium tungsten oxide is preferable. Cesium tungsten oxide is an infrared shielding agent having high absorption of infrared rays (especially infrared rays having a wavelength of about 800 nm or more and 1,200 nm or less) (that is, high infrared shielding properties) and low visible light absorption. Therefore, by using cesium tungsten oxide, the optical filter obtained can maintain good visible light transmittance and improve infrared shielding properties.

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, the generation of the impurity phase in the tungsten cesium oxide can be more reliably avoided. The upper limit of x is preferably 1, more preferably 0.5.

When y in the above 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.

As a specific example of the tungsten cesium oxide represented by the said formula (a), Cs _0.33 WO ₃ etc. are mentioned.

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

[A] The inorganic compound can also be synthesized by a known method, and can be obtained as a commercial item. For example, cesium tungsten oxide can also be obtained 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 [A] the inorganic compound in the total solid content of the composition is preferably 1% by mass, more preferably 10% by mass, still more preferably 20% by mass, still more preferably 30% by mass %. On the other hand, as an upper limit of the said content, 70 mass % is preferable, and 60 mass % is more preferable. By making content of [A] an inorganic compound into the said range, the visible light transmittance and infrared shielding property of the optical filter obtained are more favorable balance. In addition, the dispersion stability or the stability over time of the composition can be further improved. In addition, the whole solid content means [D] all components other than a solvent.

([B]polymer)

The [B] polymer is a component that improves the dispersibility of the [A] inorganic compound and the like. [B] The polymer may include one kind of polymer, or may be a mixture of two or more kinds of polymers having the same or different amine valences. The polymer whose amine value is 0 mgKOH/g is not included in the [B] polymer which is a mixture of a plurality 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 the amine value is 200 mgKOH/g. By using the polymer which has the said amine value, the dispersibility of [A] an inorganic compound improves, and the visible light transmittance and infrared shielding property of the obtained optical filter can be improved further. In addition, the "amine value" is the number of mg of KOH equivalent to the HCl equivalent required to neutralize 1 g of the polymer solid content. As the [B] polymer, when a plurality of polymers having different amine values are used in combination, the amine value of the [B] polymer is set as a weighted average value.

[B] The polymer is preferably a block copolymer. The block copolymer is preferably a block copolymer having an A block containing a functional group containing a nitrogen atom and a B block having solvophilicity. The nitrogen atom-containing functional group of the A block exhibits good adsorption to the [A] inorganic compound. Therefore, the dispersibility of [A] inorganic compound can be improved further by using the block copolymer which has an A block and a B block.

The A block preferably has, for example, a structural unit represented 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 and form a ring structure together with the bonded nitrogen atoms.

Examples of the X include a methylene group, an alkylene group having 2 to 10 carbon atoms, an arylidene group, ^{a group represented by -CONH-R 7} -(*), a group represented by -COO-R ⁸ -(*) Represented base etc. 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. (*) represents a bonding 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.

As R ² and R ³ , a chain hydrocarbon group is preferable, a chain hydrocarbon group having 1 to 5 carbon atoms is more preferable, and a methyl group, an ethyl group, and a propyl group are still more preferable.

Examples of monomers that provide the structural unit represented by the formula (1) include dimethylaminoethyl (meth)acrylate, diethylaminoethyl (meth)acrylate, (methyl) ) dimethylaminopropyl acrylate, diethylaminopropyl (meth)acrylate, and the like.

The A block may contain structural units other than the structural unit represented by the above formula (1). The content ratio 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, for example, a structural unit represented by the following formula (2).

In formula (2), R ^{4 is} each 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. R ⁶ is a hydrogen atom or a methyl group. n is an integer from 1 to 150.

As R ⁴ , ethylidene and methylethylidene are preferable. As R ⁵ , a methyl group, an ethyl group, a propyl group and a butyl group are preferable. The upper limit of n is preferably 20, more preferably 10, still more preferably 5.

Examples of monomers that provide the structural unit represented by the formula (2) include polyethylene glycol (n=1 to 5) methyl ether (meth)acrylate, polyethylene glycol (n=1 to 5) Diethyl ether (meth)acrylate, polyethylene glycol (n=1~5) propyl ether (meth)acrylate, polypropylene glycol (n=1~5) methyl ether (meth)acrylate, polypropylene glycol (n=1~5) diethyl ether (meth)acrylate, polypropylene glycol (n=1~5) propyl ether (meth)acrylate, etc.

The B block may contain structural units other than the structural unit represented by the above formula (2). As another structural unit which the B block can contain, the structural unit derived from (meth)acrylate is mentioned. Specifically, examples of monomers that provide 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 ratio of the B block in the block copolymer is preferably, for example, 30% by mass or more and 70% by mass or less.

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

Block copolymers can be synthesized by previously known methods. In addition, block co- A commercial item can also be used for the polymer and other [B] polymers. The [B] polymer may be a dispersant which coats at least a 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 still 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 the content is preferably 200 parts by mass, more preferably 100 parts by mass, and still more preferably 60 parts by mass.

([C]Organic pigment)

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

As [C] an organic dye, an organic dye or an organic pigment is mentioned, Preferably it is an organic dye. By using an organic dye, the solubility with respect to [D] a solvent improves, and the generation|occurence|production of agglomeration foreign matter can be suppressed further.

The solubility of the [C] organic dye in the [D] solvent at 20° C. and 0.1 MPa is 2 mass % or more. Therefore, the composition can obtain an optical filter having high solubility of the organic dye [C], improvement in dispersion stability or stability over time, and also with few defects. The solubility refers to the concentration (mass %) of the [C] organic dye in a solution in which the largest amount of the [C] organic dye is dissolved in the [D] solvent, that is, in a saturated solution. When [D] a solvent is a mixed solvent, it is the concentration of [C] organic dye in the saturated solution which uses a mixed solvent as a solvent. The solubility of the [C] organic dye can be achieved by the combination of the [C] organic dye and the [D] solvent. Furthermore, as the solubility of The lower limit is not particularly limited, but may be, for example, 50% by mass.

[C] The organic dye preferably has a maximum absorption wavelength in the range of wavelength 600 nm or more and 1,000 nm or less. The lower limit of the absorption maximum wavelength is more preferably 650 nm. On the other hand, the upper limit is preferably 900 nm, more preferably 850 nm. By using the [C] organic dye having the above-mentioned maximum absorption wavelength, the visible light transmittance or infrared shielding properties of the obtained optical filter can be made more favorable.

As the organic dye [C], a conventionally known organic dye can be appropriately selected and used within the range satisfying the above-mentioned solubility. As the organic dye [C], a diimine compound, a squaraine compound, a cyanine compound, a phthalocyanine compound, a naphthalocyanine compound, a quartene compound, an ammonium compound, an imine compound, and an azo compound can be used. , anthraquinone compounds, porphyrin compounds, pyrrolopyrrole compounds, oxonol compounds, ketonium compounds, hexavalent porphyrin compounds, or a combination of these. As [C] an organic dye, it is preferable to contain a phthalocyanine compound. The phthalocyanine compound is excellent in color, heat resistance, light resistance, and the like.

[C] An organic dye may be used alone or in combination of two or more. The composition preferably contains two or more kinds of [C] organic dyes. Furthermore, it may be more preferable to contain three or more kinds of [C] organic dyes. By using a plurality of [C] organic dyes in combination, the visible light transmittance or infrared shielding properties of the optical filter obtained can be made more favorable. On the other hand, in the case of using a plurality of organic dyes, dispersion stability, stability over time, and the like may be deteriorated. However, according to this composition, even if a plurality of organic dyes are used, good dispersion stability or 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, but may be 10 or 5, for example. species, or 3 species.

The lower limit of the content of [C] the organic dye in the total solid content of the composition is preferably 0.1% by mass, more preferably 0.5% by mass, and still more preferably 1% by mass. On the other hand, as an upper limit of the said content, 30 mass % is preferable, 15 mass % is more preferable, and 10 mass % is still more preferable. By making content of [C] an organic dye into the said range, the visible light transmittance and infrared shielding property of the optical filter obtained are more favorable balance.

([D]solvent)

[D] The solvent is a component that functions as a dispersion medium of the [A] inorganic compound and dissolves the [C] organic dye and the like.

[D] vehicle contains [D1] vehicle. [D1] The solvent is a solvent whose SP value is 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, as the upper limit, 11.0 (cal/cm ³ ) ^{1/2 is} preferable, and 10.5 (cal/cm ³ ) ^{1/2 is more} preferable. By using the [D1] solvent which has the SP value of the said specific range, the dispersibility of [A] inorganic compound and the solubility of [C] organic dye can be improved. Here, the SP value is a value obtained by the following Feder's formula described in RF Fedors, Polymer Engineering and Science (RF Fedors, Polym. Eng. Sci., ) 14, 147 (1974).

Feder's formula: SP value (δ)=(E _v /v) _1/2 =(ΣΔe _i /ΣΔv _i ) _1/2

E _v : evaporation energy

v: Molar volume

△e _i : Evaporation energy of atoms or groups of atoms of each component

△ v _i: molar volume of each atom or group of atoms

Examples of the solvent [D1] include n-propanol (SP value: 11.8), 1,2,5,6-tetrahydrobenzyl alcohol (SP value: 11.3), and diethylene glycol 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 acetate lactate (SP value: 9.6), ε-caprolactone (SP value: 9.6), 1,3-butanediol diacetate (SP value: 9.5), dipropylene glycol-n-propylene 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 ethyl ether acid ester (SP value: 8.8) and the like. In addition, the unit ((cal/cm ³ ) ^1/2 ) of the SP value is appropriately omitted. [D1] The solvent may be used alone or in combination of two or more.

[D1] The lower limit of the content of the solvent with respect to the entire composition is 40% by mass, preferably 50% by mass, more preferably 60% by mass, still more preferably 65% by mass. borrow By making content of [D1] solvent more than the said lower limit, the dispersibility of [A] inorganic compound or the solubility of [C] organic dye improves further. On the other hand, the upper limit of the content of the solvent [D1] is 90 mass %, preferably 80 mass %, and more preferably 75 mass %. By setting the content of the solvent [D1] to be equal to or less than the upper limit, a sufficient amount of other components can be blended, that is, by setting the content of the solvent [D1] to the range described above, the dispersion stability of the composition can be improved. In addition to the stability over time, the composition can 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.

[D] solvent may contain [D2] solvent other than [D1] solvent. [D2] The solvent is a solvent whose SP value is less than 8.8 (cal/cm ³ ) ^1/2 or more than 12.0 (cal/cm ³ ) ^1/2 . [D2] Solvents include (poly)alkanediol monoalkyl ethers, (cyclo)alkanes with SP values less than 8.8 (cal/cm ³ ) ^1/2 or more than 12.0 (cal/cm ³ ) ^1/2 base alcohol, ketone alcohol (poly) alkanediol monoalkyl ether acetate, ketone, diacetate, carboxylate, lactam, aromatic hydrocarbon, etc. For example, propylene glycol monomethyl ether acetate (SP value: 8.7) etc. are mentioned as a (poly) alkanediol monoalkyl ether whose SP value is less than 8.8 (cal/cm<^3> ) ^1/2.

The SP value of the solvent [D2] is preferably less than 8.8 (cal/cm ³ ) ^1/2 . In addition, as the lower limit of the SP value of the solvent [D2], 7 (cal/cm ³ ) ^{1/20 is} preferable, 8 (cal/cm ^{3 ) 1/2 is more} preferable, and 8.5 (cal/cm ³ ) is still more preferable. ) ^1/2 .

The lower limit of the content of the [D1] solvent in the [D] solvent is preferably 50% by mass, more preferably 70% by mass, still more preferably 80% by mass, and still more preferably 90% by mass. The [D] vehicle may contain substantially only the [D1] vehicle. [A] Dispersibility of inorganic compounds or [C] Organic The solubility of the dye is further improved, and the effects of the present invention are more fully exhibited.

[D] The vehicle preferably contains a vehicle having a cyclic structure. By using a solvent having a cyclic structure, the solubility or dispersibility becomes better. The solvent having a cyclic structure may be [D1] solvent or [D2] solvent, but is preferably [D1] solvent. The cyclic structure may be a carbocyclic ring or a heterocyclic ring. In addition, the cyclic structure may be polycyclic or monocyclic. In addition, the cyclic structure may be an aromatic ring or an aliphatic ring.

As the solvent having a cyclic structure, preferred are cyclic ketones, cyclic ethers, lactones (γ-butyrolactone, ε-caprolactone, etc.), lactamides, aromatic hydrocarbons (toluene, etc.), and these The combination. Among these, cyclic ketones, lactones, and aromatic hydrocarbons are preferable, and cyclic ketones and lactones are more preferable.

As a cyclic ketone, cyclobutanone, cyclopentanone, cyclohexanone, cycloheptanone, cyclooctanone, etc. are mentioned. Among these, cyclopentanone, cyclohexanone, and cycloheptanone are preferable, and cyclopentanone and cyclohexanone are more preferable.

As a cyclic ether, tetrahydrofuran, tetrahydropyran, etc. are mentioned.

As the lactone, γ-butyrolactone, ε-caprolactone, etc. are mentioned, and γ-butyrolactone is preferable.

As lactamide, pentane-4-lactam, 5-methyl-2-pyrrolidone, hexyl-6-lactam, 6-caprolactam, etc. are mentioned.

The lower limit of the content of the solvent having a cyclic structure in the solvent [D] is preferably 50% by mass, more preferably 70% by mass, still more preferably 80% by mass, still more preferably 90% by mass. [D] The vehicle may contain substantially only vehicles having a cyclic structure. By setting the content of the solvent having a cyclic structure in the solvent [D] to the lower limit, On the other hand, the dispersibility of [A] an inorganic compound or the solubility of [C] an organic dye is further improved, and the effect of this invention is exhibited more fully.

The lower limit of the solid content concentration (the total concentration of the components other than the [D] solvent) in the composition is preferably 5% by mass, more preferably 10% by mass. On the other hand, as an upper limit of the said solid content concentration, 50 mass % is preferable, and 40 mass % is more preferable. By setting the solid content concentration to be within the above-mentioned range, dispersibility, stability, applicability, and the like become more favorable.

([E] Polymerizable compound)

When this composition contains [E] a polymerizable compound, favorable curability, favorable heat resistance of the optical filter obtained, etc. can be exhibited. The [E] polymerizable compound refers to a compound having two or more polymerizable groups. As a polymerizable group, an ethylenically unsaturated group, an oxirane group, an oxetanyl group, an N-alkoxymethylamine group etc. are mentioned, for example. [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-alkoxymethylamine groups, more preferably two or more (meth)acryloyl compounds. [E] The polymerizable compound may be used alone or in combination of two or more.

Examples of 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 Substantial polyfunctional (meth)acrylates, alkylene oxide-modified polyfunctional (meth)acrylates, polyfunctional amine groups that are reactants of hydroxyl-containing (meth)acrylates and polyfunctional isocyanates, etc. Formate (meth)acrylic acid Esters, polyfunctional (meth)acrylates having carboxyl groups, etc., which are reaction products of (meth)acrylates having hydroxyl groups and acid anhydrides, and the like.

Here, as the aliphatic polyhydroxy compound, for example, divalent aliphatic polyhydroxy compounds such as ethylene glycol, propylene glycol, polyethylene glycol, and polypropylene glycol, or glycerin, trimethylolpropane, pentaerythritol, divalent Trivalent or higher aliphatic polyhydroxy compounds such as pentaerythritol. Examples of the (meth)acrylate having the hydroxyl group include 2-hydroxyethyl (meth)acrylate, trimethylolpropane di(meth)acrylate, pentaerythritol tri(meth)acrylate, di(meth)acrylate Pentaerythritol penta(meth)acrylate, glycerol dimethacrylate, etc. As said polyfunctional isocyanate, tolylene diisocyanate, hexamethylene diisocyanate, diphenylmethylene diisocyanate, isophorone diisocyanate, etc. are mentioned, for example. Examples of the acid anhydride include dibasic acid anhydrides such as succinic anhydride, maleic anhydride, glutaric anhydride, itaconic anhydride, phthalic anhydride, and hexahydrophthalic anhydride, or pyromellitic dianhydride, Tetrabasic acid dianhydrides such as biphenyl tetracarboxylic dianhydride and benzophenone tetracarboxylic dianhydride.

Specific examples of the compound having two or more (meth)acryloyl groups include, for example, 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)acrylic acid ester, polypropylene glycol di(meth)acrylate, bisphenoxyethanol, bis(meth)acrylate, dimethyloltricyclodecane di(meth)acrylate, 2-hydroxy-3-(meth)acrylate (meth)acrylate, 2-(2'-vinyloxyethoxy)ethyl (meth)acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol tris(meth)acrylate Methacrylate ester, pentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, tris(2-(meth)acryloyloxyethyl)phosphate, cyclic Ethane-modified dipentaerythritol hexaacrylate, succinic acid-modified pentaerythritol triacrylate, urethane (meth)acrylate compounds, and the like.

Among the compounds having two or more (meth)acryloyl groups, polyfunctional (meth)acrylates are preferred, and polyfunctional ones having three or more and 10 or less (meth)acryloyl groups are more preferred. (Meth)acrylate. Specifically, trimethylolpropane triacrylate, pentaerythritol triacrylate, dipentaerythritol pentaacrylate, and dipentaerythritol hexaacrylate are preferable.

As a compound which has two or more N-alkoxymethylamine groups, the compound which has a melamine structure, a benzoguanamine structure, a urea structure, etc. are mentioned, for example. Specific examples of the compound having two or more N-alkoxymethylamine groups include N,N,N',N',N",N"-hexa(alkoxymethyl)melamine, N,N,N',N'-tetra(alkoxymethyl)benzoguanamine, N,N,N',N'-tetrakis(alkoxymethyl)acetylene carbamide, etc.

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

([F] Polymerization initiator)

[F] The polymerization initiator is a component that starts the polymerization reaction of the [E] polymerizable compound. As [F] a polymerization initiator, a photoinitiator, a thermal polymerization initiator, etc. are mentioned, Preferably it is a photoinitiator. As a result, photosensitivity (radiosensitivity) can be imparted to the composition. linear). The photopolymerization initiator refers to a compound that generates an active species that initiates polymerization of the polymerizable compound [E] by exposure to radiation such as visible rays, ultraviolet rays, extreme ultraviolet rays, electron beams, and X rays. [F] The polymerization initiator may be used alone or in combination of two or more.

Examples of the polymerization initiator [F] include thioxanthone-based compounds, acetophenone-based compounds, biimidazole-based compounds, triazine-based compounds, O-acyl oxime-based compounds, onium salt-based compounds, and benzoin-based compounds. Compounds, benzophenone-based compounds, α-diketone-based compounds, polynuclear quinone-based compounds, bisazo-based compounds, imidate-based compounds, and the like. Among these, a thioxanthone-based compound, an acetophenone-based compound, a biimidazole-based compound, a triazine-based compound, or an O-acyl oxime-based compound is preferred, and an O-acyl oxime-based compound is more preferred.

Examples of the thioxanthone-based compound include thioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone, 2-isopropylthioxanthone, 4-isopropylthioxanthone, 2,4 -Dichlorothioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, 2,4-diisopropylthioxanthone, etc.

Examples of the acetophenone-based compound include 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one, 2-benzyl-2-dimethylene Amino-1-(4-morpholinylphenyl)butan-1-one, 2-(4-methylbenzyl)-2-(dimethylamino)-1-(4-morpholine phenyl) butan-1-one and the like.

As the biimidazole-based compound, for example, 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-trichloro phenyl)-4,4',5,5'-tetraphenyl-1,2'- Biimidazole etc.

Furthermore, in the case of using a biimidazole-based compound, it is preferable to use a hydrogen donor in combination from the viewpoint that the sensitivity can be improved. The "hydrogen donor" as used herein refers to a compound that can donate a hydrogen atom to a radical generated from a biimidazole-based compound by exposure to light. Examples of the hydrogen donor include thiol-based hydrogen donors such as 2-mercaptobenzothiazole and 2-mercaptobenzoxazole; 4,4'-bis(dimethylamino)benzophenone, 4,4'-bis(dimethylamino)benzophenone, Amine-based hydrogen donors such as 4'-bis(diethylamino)benzophenone.

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

As the O-acyl oxime-based compound, 1,2-octanedione-1-[4-(phenylthio)phenyl]-2-(O-benzyl oxime), ethanone-1 -[9-ethyl-6-(2-methylbenzyl)-9H-carbazol-3-yl]-1-(O-acetyloxime), ethanone-1-[9-ethyl] Alkyl-6-(2-methyl-4-tetrahydrofurylmethoxybenzyl)-9H-carbazol-3-yl]-1-(O-acetyloxime), ethanone-1-[ 9-ethyl-6-{2-methyl-4-(2,2-dimethyl-1,3-dioxolane)methoxybenzyl}-9H-carbazole-3 -Base]-1-(O-acetyl oxime) and so on. As commercially available O-acyl oxime compounds, NCI-831, NCI-930 (the above are manufactured by ADEKA Co., Ltd.), OXE-03, and OXE-04 (the above are BASF ( BASF) company) and so on.

When a photopolymerization initiator is used, a sensitizer may be used together. As the sensitizer, for example, 4,4'-bis(dimethylamino)benzophenone, 4,4'-bis(diethylamino)benzophenone, 4-bis(diethylamino)benzophenone, Ethylaminoacetophenone, 4-dimethylaminophenacetate Ketone, Ethyl 4-dimethylaminobenzoate, 2-ethylhexyl 4-dimethylaminobenzoate, 2,5-bis(4-diethylaminobenzylidene)cyclohexanone , 7-diethylamino-3-(4-diethylaminobenzyl)coumarin, 4-(diethylamino)chalcone, etc.

[F] The lower limit of the content of the polymerization initiator is preferably 1 part by mass, more preferably 5 parts by mass, with respect to 100 parts by mass of the [E] polymerizable compound. On the other hand, as the upper limit of the content, 100 parts by mass is preferable, and 40 parts by mass is more preferable.

(binder resin)

A binder resin may be further contained in this composition. Furthermore, the [B] polymer is not contained in the binder resin. Although it does not specifically limit as a binder resin, Resin which has an acidic functional group, such as a carboxyl group and a phenolic hydroxyl group, is preferable. Among them, a polymer having a carboxyl group (hereinafter, also referred to as a "carboxyl group-containing polymer") is preferable. Examples of the carboxyl group-containing polymer include an ethylenically unsaturated monomer having one or more carboxyl groups (hereinafter, also referred to as "unsaturated monomer (1)") and other copolymerizable ethylenically unsaturated monomers. A copolymer of a monomer (hereinafter, also referred to as "unsaturated monomer (2)).

As the unsaturated monomer (1), for example, (meth)acrylic acid, maleic acid, maleic anhydride, mono[2-(meth)acryloyloxyethyl]succinate, ω -Carboxy polycaprolactone mono(meth)acrylate, p-vinyl benzoic acid, etc.

Examples of the unsaturated monomer (2) include N-substituted maleimides such as N-phenylmaleimide and N-cyclohexylmaleimide, styrene, α -Aromatic vinyl compounds such as methylstyrene, p-hydroxystyrene, p-hydroxy-α-methylstyrene, p-vinylbenzyl glycidyl ether, acenaphthene, methyl (meth)acrylate, (methyl) n-butyl 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 (polymerization degree 2~10) methyl ether (meth)acrylate, polyethylene glycol (polymerization degree 2~10) mono(meth)acrylic acid Esters, polypropylene glycol (polymerization degree 2~10) mono(meth)acrylate, cyclohexyl(meth)acrylate, isobornyl(meth)acrylate, tricyclo[5.2.1.0 ^2,6 ] decane- 8-yl(meth)acrylate, dicyclopentenyl(meth)acrylate, glycerol mono(meth)acrylate, 4-hydroxyphenyl(meth)acrylate, ethylene oxide of p-cumylphenol Modified (meth)acrylate, glycidyl (meth)acrylate, 3,4-epoxycyclohexylmethyl (meth)acrylate, 3-[(meth)acryloyloxymethyl]oxy Hetetane, (meth)acrylates such as 3-[(meth)acryloyloxymethyl]-3-ethyloxetane, cyclohexyl vinyl ether, isobornyl vinyl ether, Tricyclo[5.2.1.0 ^2,6 ]decan-8-yl vinyl ether, pentacyclopentadecyl vinyl ether, 3-(vinyloxymethyl)-3-ethyloxetane, etc. Vinyl ether, polystyrene, polymethyl (meth)acrylate, n-butyl (meth)acrylate, polysiloxane are equal to the giant single (meth)acryloyl group at the end of the polymer molecular chain body etc.

Moreover, as a binder resin, it can also be used for the carboxyl group-containing polymer which has a polymerizable unsaturated bond, such as a (meth)acryloyl group, in a side chain. Moreover, polysiloxane etc. can also be used as a binder resin.

(additive)

The composition may also contain various additives as required.

Examples of additives include surfactants, adhesion promoters, antioxidants, ultraviolet absorbers, anti-agglomeration agents, residue improvers, developability improvers, and the like.

As a surfactant, a fluorine surfactant, a silicone surfactant, etc. are mentioned. The content of the surfactant in the total solid content of the composition can be, for example, 0.01 mass % or more and 5 mass % or less.

Examples of the adhesion promoter include vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris(2-methoxyethoxy)silane, N-(2-aminoethyl)-3 -aminopropylmethyldimethoxysilane, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-glycidyl Glyceryloxypropyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-chloropropane Methyldimethoxysilane, 3-chloropropyltrimethoxysilane, 3-methacryloyloxypropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, etc.

Examples of antioxidants include: 2,2-thiobis(4-methyl-6-tert-butylphenol), 2,6-di-tert-butylphenol, pentaerythritol tetrakis[3-(3,5 -Di-tert-butyl-4-hydroxyphenyl)propionate], 3,9-bis[2-[3-(3-tert-butyl-4-hydroxy-5-methylphenyl)- Propionyloxy]-1,1-dimethylethyl]-2,4,8,10-tetraoxa-spiro[5.5]undecane, thiodiethylenebis[3-(3,5- Di-tert-butyl-4-hydroxyphenyl) propionate] and the like. The content of the antioxidant in the total solid content of the composition can be, for example, 0.01 mass % or more and 5 mass % or less.

As the ultraviolet absorber, 2-(3-tert-butyl-5-methyl-2-hydroxyl phenyl)-5-chlorobenzotriazole, alkoxybenzophenones, etc.

As an anti-agglomeration agent, sodium polyacrylate etc. are mentioned.

As the residue improving agent, 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, etc.

As the developability improver, mono[2-(meth)acryloyloxyethyl] succinate, mono[2-(meth)acrylooxyethyl] phthalate, ω -Carboxy polycaprolactone mono(meth)acrylate etc. agent etc.

(Preparation)

It does not specifically limit as a preparation method of this composition, It can prepare by mixing each component. For example, a method of first preparing a dispersion liquid containing [A] an inorganic compound, [B] a polymer, and [D] a solvent, adding [C] an organic dye or other components to the dispersion liquid, and mixing them. At this time, [D] a solvent may further be added. The dispersion or the composition can also be subjected to filtration treatment as necessary to remove aggregates.

<Method for forming infrared shielding film for solid-state imaging element>

The method for forming an infrared shielding film for a solid-state imaging device according to an embodiment of the present invention includes a step (step 1) of forming a coating film on one surface side of a substrate, and forming the coating film with the composition for a solid-state imaging device.

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

According to this formation method, by using a composition with high dispersion stability and stability over time, 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. In addition, when the formation method includes Step 2 and Step 3, it has good patterning properties.

(step 1)

In step 1, a coating film is formed on one surface side of a substrate (support) using this composition. As said board|substrate, a glass substrate, a synthetic resin board|substrate, etc. are mentioned. In addition, the shape of a board|substrate is not limited to a plate shape. In addition, when incorporating an infrared shielding film into a solid-state imaging element to be described later, the transparent substrate, microlenses, color filters, etc., which are constituent elements of the solid-state imaging element, correspond to the substrate.

The formation of the coating film can be usually performed by coating the composition. Suitable coating methods such as spray coating, roll coating, spin coating (spin coating), slot die coating (slot coating), and bar coating can be used for the coating.

After coating, prebaking is performed to evaporate the solvent, thereby forming a coating film. The conditions of the heating and drying of the prebaking are, for example, 70° C. or more and 110° C. or less, and about 1 minute or more and 10 minutes or less.

(step 2)

In step 2, at least a part of the coating film is irradiated with radiation. Examples of the light source of radiation used for exposure of the coating film include 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, and argon ion lasers. , yttrium aluminum garnet (yttrium aluminum garnet, YAG) laser, XeCl molecular laser, nitrogen laser and other laser light sources. As an exposure light source, an ultraviolet light emitting diode (LED) can also be used. The wavelength is preferably radiation in the range of 190 nm or more and 450 nm or less. The radiation exposure is generally 10J / m ² or more and 50,000J / or less about ² m.

(step 3)

In step 3, the coating film after irradiation with radiation is developed. The developer is usually an alkaline developer or an organic solvent developer. In addition, water washing is usually performed after image development.

The developing solution is usually an alkaline developing solution. As an alkaline developer, for example, sodium carbonate, sodium bicarbonate, sodium hydroxide, potassium hydroxide, tetramethylammonium hydroxide, choline, 1,8-diazabicyclo-[5.4.0]- Aqueous solutions of 7-undecene, 1,5-diazabicyclo-[4.3.0]-5-nonene, etc. For example, an appropriate amount of water-soluble organic solvents such as methanol and ethanol, surfactants, etc. may be added to the alkaline developer.

As the organic solvent developer, acetone, methyl ethyl ketone, 2-octanone, 2-nonanone, 2-heptanone, 3-heptanone, 4-heptanone, 2-hexanone, 3-heptanone, - Ketones such as hexanone, diisobutyl ketone, methyl cyclohexanone, acetophenone, methyl acetophenone, 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, ethyl crotonate , methyl propionate, ethyl propionate, ethyl 3-ethoxypropionate, methyl lactate, ethyl lactate, propyl lactate, butyl lactate, isobutyl lactate, amyl lactate, isoamyl lactate , methyl 2-hydroxyisobutyrate, ethyl 2-hydroxyisobutyrate, methyl benzoate, ethyl benzoate, phenyl acetate, Benzyl acetate, methyl phenyl acetate, benzyl formate, phenyl ethyl formate, methyl 3-phenyl propionate, benzyl propionate, ethyl phenyl acetate, 2-phenyl ethyl acetate and other esters .

As a development treatment method, a shower development method, a spray development method, a dip development method, a puddle development method, etc. can be applied. The image development conditions are about 5 seconds or more and 300 seconds or less at normal temperature.

By the development, the non-exposed portion of the coating film is dissolved and removed. Then, by post-baking as needed, the infrared shielding film patterned into a predetermined shape can be obtained. The post-baking conditions are usually about 180° C. or more and 280° C. or less, and 1 minute or more and 60 minutes or less.

In addition, when this composition does not contain [E] a polymerizable compound and [F] a polymerization initiator, it is not necessary to perform hardening processing, such as exposure, unlike the said formation method. In addition, the development process may not be performed, and in this case, an unpatterned infrared shielding film can be formed.

The lower limit of the average film thickness of the infrared shielding film for solid-state imaging elements formed as described above is usually 0.5 μm, preferably 1 μm. On the other hand, as an upper limit of the said average film thickness, it is 5 micrometers normally, Preferably it is 3 micrometers. When the average film thickness of the infrared shielding film is within the above-mentioned range, the balance between the visible light transmittance and the infrared shielding property becomes more favorable.

The infrared shielding film is preferably incorporated into the solid-state imaging element as a constituent member. In this case, the infrared shielding film functions as an optical filter (infrared cut filter) alone. By incorporating an infrared shielding film into the solid-state imaging element, it is preferable to obtain a large process margin and the like. in infrared When the shielding film is incorporated into the solid-state imaging element, the infrared shielding film can be arranged, for example, on the outer surface side of the microlens of the solid-state imaging element, between the microlens and the color filter, and between the color filter and the photodiode. between the bodies, etc. The infrared shielding film is preferably laminated between the microlens and the color filter or between the color filter and the photodiode.

As the optical filter, what has an infrared shielding film on the surface layer of a transparent substrate may be sufficient. As the transparent substrate, glass, transparent resin, or the like can be used. As said transparent resin, polycarbonate, polyester, aromatic polyamide, polyamide imide, polyimide, etc. are mentioned. The optical filter can also be preferably used as an infrared cut filter in a solid-state imaging element.

Solid-state imaging devices with infrared shielding films (optical filters) are used in digital still cameras, mobile phone cameras, digital video cameras, personal computer (PC) cameras, surveillance cameras, automotive cameras, and portable information terminals , computers, video game consoles, medical equipment, etc.

[Example]

Hereinafter, the present invention will be specifically described based on Examples, but the present invention is not limited to these Examples. In addition, the characteristic of the polymer obtained by the synthesis example was measured by the following method.

[Weight average molecular weight (Mw), number average molecular weight (Mn) and degree of dispersion (Mw/Mn)]

The Mw and Mn of the polymer were determined by gel permeation chromatography (Gel Permeation Chromatography, GPC) columns (2 G2000HXL, 1 G3000HXL, and 1 G4000HXL) by Tosoh Corporation under the following analysis conditions by coagulation. glue Permeation chromatography (GPC) determination.

The degree of dispersion (Mw/Mn) was calculated from the measurement results of Mw and Mn.

(analysis conditions)

Dissolution medium: tetrahydrofuran

Flow: 1.0mL/min

Sample concentration: 1.0% by mass

Sample injection volume: 100 μL

Column temperature: 40℃

Detector: Differential Refractometer

Standard material: monodisperse polystyrene

<Synthesis Example 1> (Synthesis of Organic Dye (C-1))

Using the method described in paragraphs [0020] to [0025] (Example 1) of Japanese Patent Laid-Open No. 05-25177, an organic dye (C-1), which is a phthalocyanine compound represented by the following formula, was synthesized.

<Synthesis example 2> (Synthesis of organic dye (C-2))

Using the method described in paragraph [0075] (Example 4) of Japanese Patent Laid-Open No. 2016-204536, an organic color that is a phthalocyanine compound represented by the following formula was synthesized prime (C-2).

<Synthesis example 3> (Synthesis of organic dye (C-3))

Using the method described in Japanese Patent Laid-Open No. 1-228960, an organic dye (C-3), which is a squaraine ylide compound represented by the following formula, was synthesized.

<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 Japanese Patent Laid-Open No. 2-138382.

In addition to this, the organic dyes used are as follows.

. Organic dye (C-5): "FDN-002" (phthalocyanine compound) from Yamada Chemical Industry Co., Ltd.

. Organic dye (C-6): "FDR-004" (phthalocyanine compound) from Yamada Chemical Industry Co., Ltd.

. Organic dye (C-7): "FDN-001" (phthalocyanine compound) from Yamada Chemical Industry Co., Ltd.

<Synthesis Example 5 to Synthesis Example 7> (Synthesis of Polymer (B-1) to Polymer (B-3))

Using the method described in the literature (Macromolecules 1992, 25, p5907-5913), polymer (B-1) to polymer (B) having the monomer composition ratio (mass ratio) described in Table 1 below were obtained -3) Synthesis. A polymer having a diblock structure containing a block of a monomer (DAMA) having an adsorption group for an inorganic compound as a pigment and a block of other components can be obtained. In addition, the solution after the reaction was quenched with methanol, and the obtained reaction solution was washed with a 7 mass % sodium hydrogencarbonate aqueous solution and then with water. Then, by carrying out solvent substitution to propylene glycol monomethyl ether acetate (Propylene Glycol Monomethyl Ether Acetate, PGMEA), the polymer solution described in the following Table 1 was obtained in all yields 80-82 mass %. Table 1 shows the amine value, Mw, Mw/Mn, and solid content of each polymer obtained. In addition, DAMA in the table represents dimethylaminoethyl methacrylate, EHMA represents 2-ethylhexyl methacrylate, nBMA represents n-butyl methacrylate, PME-200 (“No Oil Co., Ltd. product”) Blemmer") stands for methoxy polyethylene glycol monomethacrylate. Specifically, PME-200 is a polymer of a monomer 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))

The synthesis of polymer (B-8) having the monomer composition ratio (mass ratio) described in Table 1 below was carried out in the same manner as in the methods described in Synthesis Examples 5 to 7, except that all the monomers were polymerized together. . The polymer (B-8) is a random copolymer.

<Synthesis Example 9> (Synthesis of Cesium Tungsten Oxide Powder)

_{Tungsten cesium 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: Polymer (B-1) to Polymer (B-3) of Table 1 synthesized in Synthesis Example 5 to Synthesis Example 7

. B-4: "BYK-LPN6919" from BYK-Chemie (solid content concentration 61 mass %, amine value 120 mgKOH/g)

. B-5: "BYK-2001" from BYK-Chemie (solid content concentration 46 mass %, amine value 29 mgKOH/g)

. B-6: "BYK-2000" from BYK-Chemie (solid content concentration 40 mass %, amine value 4 mgKOH/g)

. B-7: "BYK-LPN22102" from BYK-Chemie (solid content concentration 38.5 mass %, amine value 23 mgKOH/g)

. B-8: Polymer (B-8) of Table 1 synthesized in Synthesis Example 8

(solvent)

CPN: cyclopentanone (SP value: 10.0)

CHN: cyclohexanone (SP value: 9.9)

GBL: γ-butyrolactone (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 Liquid (X-1))

25.00 parts by mass of the cesium tungsten oxide, 13.11 parts by mass of the 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 particles having a diameter of 0.1 mm, and dispersed with a paint shaker to obtain a dispersion liquid (X-1) having an average particle diameter (D50) of 19 nm. In addition, the average particle diameter was measured by the dynamic light scattering (dynamic light scattering, DLS) method using the light scattering measuring apparatus ("ALV-5000" of German ALV company).

[Preparation Example 2 to Preparation Example 15] (Preparation of Dispersion Liquid (X-2) to Dispersion Liquid (X-15))

Except having used each component shown in Table 2, it carried out similarly to Preparation Example 1, and obtained each Dispersion (X-2) ~ dispersion (X-15) were obtained. The average particle diameter (D50) of the particle|grains in the obtained dispersion liquid is shown together in Table 2. CsWO in Table 2 represents cesium tungsten oxide obtained in Synthesis Example 9.

[Example 1]

Measure 50.00 parts by mass of the dispersion liquid (X-1), the organic pigment (C-1) in a container 0.75 parts by mass, "KAYARAD DPHA" (a mixture of dipentaerythritol hexaacrylate and dipentaerythritol pentaacrylate) as a polymerizable compound, 6.26 parts by mass, moxa as a polymerization initiator 1.46 parts by mass of "NCI-930" (O-acetyloxime-based compound) from ADEKA, and "FTX-218D" (fluorine-based surfactant) from NEOS as a surfactant ) 0.02 parts by mass, 0.01 parts by mass of BASF's "Irganox 1010" (phenolic antioxidant) as an antioxidant, and 41.50 parts by mass of cyclopentanone (CPN) as an additional solvent, which were mixed with a mixer. mix. The composition (Z-1) of Example 1 was obtained by subjecting 200 mL of the mixture to pressure filtration at 0.5 MPa for 3 minutes using a 0.5 μm filter made of polytetrafluoroethylene (PTFE). The solubility of the organic dye (C-1) in the solvent (CPN) at 20° C. and 0.1 MPa is 2 mass % or more.

Here, the solubility is obtained by the following method. First, an organic dye is added to the solvent (the amount added at this time is an amount equivalent to 10% by mass relative to the entire solution), the obtained solution is heated to 50°C, and then left to stand at room temperature (20°C) for 12 hours . The solubility (20° C.) of each dye with respect to the solvent was calculated based on the amount of each organic dye remaining dissolved after being left to stand.

[Example 2 to Example 23, Comparative Example 1 to Comparative Example 13]

The compositions (Z-2) to the compositions of Examples 2 to 23 and Comparative Examples 1 to 13 were obtained in the same manner as in Example 1, except that the compositions of the respective components were shown in Tables 1 to 7. (Z-23), composition (Y-1) ~ composition (Y-13). In Tables 3 to 7, the organic pigments used are shown together with respect to the solvent used solubility. In addition, the solvent derived from the polymer solution is also contained in each composition. The values in the table are values that also take these into account.

[Evaluation]

Using each of the obtained compositions, the following evaluations were performed. The evaluation results are shown in Tables 3 to 7.

(dispersion stability)

Using a 0.5 μm polytetrafluoroethylene (PTFE) filter, 200 mL of each composition was subjected to pressure filtration at 0.5 MPa for 3 minutes. Based on the recovery rate of the filtrate at this time, dispersion stability (filterability, precipitation inhibition) was evaluated by the following criteria. In the case of A or B, it was evaluated that the dispersion stability was good, and in the case of A, it was evaluated to be particularly excellent. Furthermore, when the collection of aggregates and the like is large and the recovery rate is less than 90% (C), the filtration becomes insufficient, and the productivity is remarkably lowered.

A: More than 95%

B: More than 90% and less than 95%

C: less than 90%

The following evaluation was implemented using the said filtered composition.

Each composition was apply|coated by the spin coating method on a glass substrate so that it might become a predetermined film thickness. Then, the coating film was heated at 100° C. for 120 seconds, and was exposed ^{to 1000 mJ/cm 2 by an i-ray stepper.} Next, by heating at 220 degreeC for 300 second, the infrared shielding film with an average film thickness of 1.40 micrometers - 1.60 micrometers was produced on a glass substrate. The respective average film thicknesses are shown in Tables 3 to 7. In addition, the film thickness was measured using a stylus-type level difference meter (“α Step IQ” from Yamato Scientific Co., Ltd.). Next, using a spectrophotometer (“V-7300” from JASCO Corporation), the transmittance in each wavelength region of the infrared shielding film produced on the glass substrate was measured in comparison with the glass substrate. Based on the obtained spectrum, evaluation was performed according to the evaluation criteria described below.

(Visible light transmittance)

Calculate the average transmittance of visible light with wavelengths of 450nm-550nm. When the average transmittance is less than 70%, the sensitivity of the solid-state imaging element when used as an infrared shielding film decreases. In addition, about the said average transmittance, it evaluated based on the following criteria.

A: More than 80%

B: More than 70% and less than 80%

C: less than 70%

(infrared shielding property 1)

The average transmittance of infrared rays with wavelengths of 700nm-900nm was calculated. When the average transmittance is 20% or more, the amount of noise of the solid-state imaging element increases when used as an infrared shielding film. In addition, about the said average transmittance, it evaluated based on the following criteria.

A: Less than 15%

B: More than 15% and less than 20%

C: 20% or more

(infrared shielding property 2)

Regarding the transmittance of infrared rays having a wavelength of 1200 nm, it can be said that the transmittance is less than 15%, and practically good infrared shielding properties are exhibited. About the transmission of wavelength 1200nm The over rate was evaluated using the following criteria.

A: Less than 10%

B: More than 10% 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 (450nm-550nm) and the average transmittance (N) in the infrared region (700nm-900nm) was obtained, and practical performance was estimated. The higher the numerical value of the S/N ratio, the better the performance, and when it is 5 or more, it is judged that it can be used at a practical level. Regarding the S/N ratio, the following criteria were used for evaluation.

A: 5 or more

B: less than 5

(defect inhibitory)

A cured film having a film thickness of 1 μm was formed by the same method as in paragraph [0139]. The defect density (Defect density) of the cured film was measured using a defect/foreign material inspection apparatus ("KLA 2351" of KLA-Tencor Corporation). It can be judged that the smaller the value of the defect density, the higher the defect suppression property. In addition, a defect means the detection point whose size is 1 micrometer or more. Based on the defect density, defect suppression was evaluated using the following criteria.

A: 10 / cm ² or less

B: More than 10/cm ² and 50/cm ² or less

C: more than 50/cm ²

(Stability over time: viscosity increase rate)

After storing the composition at 40° C. for 3 days, the viscosity before and after the storage was measured. In addition, the viscosity was measured using the E-type viscometer (E-type viscometer RE-80L by Toki Sangyo Co., Ltd.), in the state which kept the coating liquid at 20 degreeC. When the viscosity before storage is V1 and the viscosity after storage is V2, the value of (|V2-V1|/V1)×100 is defined as the viscosity increase rate (%). Based on the said viscosity increase rate, it evaluated by the following reference|standard. The lower the numerical value of the viscosity increase rate, the better, and it was judged that it was practical when it was less than 10%.

A: Less than 5%

B: 5% or more and less than 10%

C: 10% or more

(Stability over time: number of defects)

After the composition was stored at 40° C. for 3 days, the number of defects was measured using the composition after storage. The measurement method and criteria were the same as those for the evaluation of the "defect suppression" described above.

(pattern)

For composition Z-1 to composition Z-13, composition Z-17 to composition Z-18, composition Z-23, composition Y-1 to composition Y-8 and composition Y-10, use The spin coating method forms a coating film with a thickness of 1 μm on a silicon substrate. Next, after heating at 100° C. for 120 seconds, exposure ^{at 1000 mJ/cm 2} was performed with an i-ray stepper through a mask having an L/S pattern of 50 μm. The non-exposed part was removed by immersing the exposed board|substrate in acetone and developing it. Next, an infrared shielding film having an L/S pattern was produced by heating at 220° C. for 300 seconds. As a result of observation with an optical microscope, it was confirmed that an L/S pattern with a line width of 50 μm was formed.

About the composition Z-14 to the composition Z-16, the composition Z-19 to the composition Z-22 and the composition Y-9, except that the developer was changed to a 2.38% TMAH solution, infrared rays were produced by the same method. masking film. As a result of observation with an optical microscope, it was confirmed that an L/S pattern of 50 μm was formed.

[Table 4]

As shown in Tables 3 to 7, it can be seen that the compositions Z-1 to Z-23 of Examples 1 to 23 have high dispersion stability and stability over time, and also have good pattern properties. Moreover, it turns out that the infrared shielding film (optical filter) obtained from these compositions has few defects, and has both favorable visible light transmittance and infrared shielding property.

[Industrial Availability]

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

Claims (12)

A composition for a solid-state imaging element, comprising 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, and the solvent includes a solubility parameter of 8.8 (cal/g) cm ³ ) ^1/2 or more and 12.0 (cal/cm ³ ) ^1/2 or less, and a solvent having a cyclic structure, the content of the specific solvent with respect to the entire solid-state imaging element composition is 40 mass % or more and 90 mass % or less, the content of the specific solvent relative to the entire solvent is 50 mass % or more, and the solubility of the organic dye in the solvent at 20° C. and 0.1 MPa is 2 mass % above. The composition for a solid-state imaging device according to claim 1, comprising two or more of the organic dyes. The solid-state imaging element composition according to claim 1 or 2, wherein the solid content concentration in the solid-state imaging element composition is 5 mass % or more and 50 mass % or less. The composition for a solid-state imaging device according to claim 1, wherein the solvent having a cyclic structure is a cyclic ketone, a cyclic ether, a lactone, a lactamide, an aromatic hydrocarbon, or a combination thereof . The composition for a solid-state imaging element according to claim 1 or claim 2, wherein the organic dye has a wavelength of 600 nm or more and 1,000 nm or less. has a maximum absorption wavelength in the range. The composition for a solid-state imaging device according to claim 1 or claim 2, wherein the organic dye is a diimine compound, a squaraine compound, a cyanine compound, a phthalocyanine compound, or a naphthalocyanine compound Compounds, quartane compounds, ammonium compounds, imine compounds, azo compounds, anthraquinone compounds, porphyrin compounds, pyrrolopyrrole compounds, oxonol compounds, ketonium compounds, hexavalent porphyrin compounds or these The combination. The composition for a solid-state imaging device according to claim 1 or claim 2, wherein the polymer is a block copolymer having a block containing a functional group containing a nitrogen atom , and blocks with solvophilicity. The composition for a solid-state imaging device according to claim 1 or claim 2, wherein the inorganic compound is cesium tungsten oxide, quartz, magnetite, alumina, titania, zirconia, spinel, or the like some combination. The composition for a solid-state imaging element according to claim 1 or claim 2, further comprising a polymerizable compound. The composition for a solid-state imaging element according to claim 1 or 2, wherein the concentration of the inorganic compound relative to the total solid content in the composition for a solid-state imaging element is 1 mass % or more and 70% by mass mass % or less. A method for forming an infrared shielding film for a solid-state imaging device, comprising the step of forming a coating film on one surface side of a substrate, by the solid-state imaging device according to any one of the first to tenth claims in the scope of the application. composition to form the coating. The method for forming an infrared shielding film for a solid-state imaging device according to claim 11, further comprising: irradiating at least a part of the coating film with radiation, and developing the coating film after the radiation irradiation A step of.