JP2024090819A - Radiation-sensitive composition, cured product, lens manufacturing method, display device, solid-state imaging device, imaging device, and polymer - Google Patents

Abstract

[Problem] To provide a radiation-sensitive composition that has excellent patterning properties and patterning margins, has a high refractive index after curing, and reduces outgassing after curing. [Solution] A radiation-sensitive composition comprising [A] a polymer having a partial structure represented by formula (1), [B] a polymerization initiator, and [C] a polymerizable compound. TIFF2024090819000023.tif65170 [Selected Figure] None

Description

The present invention relates to a radiation-sensitive composition, a cured product, a lens manufacturing method, a display device, a solid-state imaging device, an imaging device, and a polymer.

Various image sensors, such as CCD (Charge-Coupled Device) image sensors and CMOS (Complementary Metal-Oxide-Semiconductor) image sensors, are used as solid-state imaging elements in imaging devices such as cameras. In solid-state imaging elements, tiny condensing lenses (hereinafter also referred to as "microlenses") are regularly arranged in order to collect light on a light receiving element (photodiode) and improve the sensor sensitivity. In addition, in various display elements such as organic electroluminescence (organic EL) elements and liquid crystal display elements, a structure in which a microlens is provided on the light output side of each pixel is also adopted in order to improve light extraction efficiency and adjust the viewing angle. In self-luminous displays such as organic EL display devices, attempts are being made to improve brightness and adjust the viewing angle by forming microlenses from a highly refractive material.

Thermal flow method is known as one method for forming microlenses (see, for example, Patent Document 1). The thermal flow method is a method in which a radiation-sensitive composition is used to form a pattern corresponding to the arrangement of microlenses on top of a light-receiving element or a light-emitting element, and then the pattern formed by the radiation-sensitive composition is subjected to a heat treatment to cause the pattern to flow, thereby forming a hemispherical microlens array.

In addition, in the past, in organic EL elements and liquid crystal display elements, a radiation-sensitive composition was applied onto a substrate, a pattern was formed by exposure and development, and then a heat treatment was performed to form a planarized film with a high refractive index (see, for example, Patent Document 2).

JP 2020-101659 A JP 2017-107024 A

The problem that the present invention aims to solve is to provide a radiation-sensitive composition that has excellent patterning characteristics and patterning margins, a high refractive index of the cured product, and reduced outgassing of the cured product.

The present invention provides the following [1] to [12].
[1] [A] a polymer having a partial structure represented by the following formula (1),
[B] a polymerization initiator,
[C] A radiation-sensitive composition comprising a polymerizable compound.
[2] The radiation-sensitive composition according to the above [1], wherein Ar ¹ is a benzene ring or a naphthalene ring.
[3] The radiation-sensitive composition according to the above [1], wherein Ar ² is a monocyclic aromatic hydrocarbon ring or a condensed polycyclic aromatic hydrocarbon ring.
[4] The radiation-sensitive composition according to [1] above, wherein R ³ is a hydroxyl group.
[5] A cured product obtained by curing the radiation-sensitive composition according to [1] above.
[6] A step of applying the radiation-sensitive composition according to [1] above onto a substrate to form a coating film;
exposing a portion of the coating to radiation;
and developing the irradiated coating to form a pattern on the substrate.
[7] The method for manufacturing a lens according to [6] above, further comprising a step of heating the pattern to form a lens.
[8] The method for manufacturing a lens according to [7] above, wherein the temperature at which the pattern is heated is 100° C. or less.
[9] A display device comprising the cured product according to [5] above.
[10] A solid-state imaging device comprising the cured product according to [5] above.
[11] An imaging device comprising the solid-state imaging element according to [10].
[12] A polymer having a partial structure represented by the following formula (1):

(In formula (1),
^Ar1 represents an aromatic ring;
^Ar2 represents an aromatic ring or a heterocycle;
R ¹ represents a cyano group, a halogen atom, or a hydrocarbon group;
^R2 represents a hydrocarbon group, an alkoxy group, a cycloalkoxy group, an aryloxy group, an aralkyloxy group, an alkylthio group, a cycloalkylthio group, an arylthio group, an aralkylthio group, an acyl group, a halogen atom, a nitro group, a cyano group, or a substituted amino group;
^R3 represents an alkali-soluble group;
X represents an oxygen atom or a sulfur atom;
^Ar3 represents a tetravalent organic group;
A represents an alkylene group;
k represents an integer of 0 to 4;
l, m, and n each independently represent an integer of 0 or more.

The manufacturing method of the present invention can provide a radiation-sensitive composition that has excellent patterning characteristics and patterning margins, a high refractive index of the cured product, and reduced outgassing of the cured product.

The following describes in detail the matters related to the embodiments. In this specification, a numerical range described using "~" means that the numerical range includes the numerical ranges before and after "~" as the lower and upper limits.

<Radiation-sensitive composition>
The radiation-sensitive composition of the present invention (hereinafter also referred to as “the composition”) contains [A] a polymer having a partial structure represented by formula (1), [B] a polymerization initiator, and [C] a polymerizable compound.

(In formula (1),
^Ar1 represents an aromatic ring;
^Ar2 represents an aromatic ring or a heterocycle;
R ¹ represents a cyano group, a halogen atom, or a hydrocarbon group;
^R2 represents a hydrocarbon group, an alkoxy group, a cycloalkoxy group, an aryloxy group, an aralkyloxy group, an alkylthio group, a cycloalkylthio group, an arylthio group, an aralkylthio group, an acyl group, a halogen atom, a nitro group, a cyano group, or a substituted amino group;
^R3 represents an alkali-soluble group;
X represents an oxygen atom or a sulfur atom;
^Ar3 represents a tetravalent organic group;
A represents an alkylene group;
k represents an integer of 0 to 4;
l, m, and n each independently represent an integer of 0 or more.

Here, in this specification, "hydrocarbon" includes chain hydrocarbons, alicyclic hydrocarbons, and aromatic hydrocarbons. "Chain hydrocarbon" means a straight-chain hydrocarbon and a branched hydrocarbon that does not include a ring structure in the main chain and is composed only of a chain structure. However, it may be saturated or unsaturated. "Alicyclic hydrocarbon" means a hydrocarbon that contains only an alicyclic hydrocarbon structure as a ring structure and does not contain an aromatic ring structure. However, it does not have to be composed only of an alicyclic hydrocarbon structure, and it also includes those that have a chain structure as a part. "Aromatic hydrocarbon" means a hydrocarbon that contains an aromatic ring structure as a ring structure. However, it does not have to be composed only of an aromatic ring structure, and it may contain a chain structure or an alicyclic hydrocarbon structure as a part. In addition, the aromatic ring structure of the aromatic hydrocarbon may be a single ring or a condensed ring. In addition, the ring structure of the alicyclic hydrocarbon and the aromatic hydrocarbon may have a substituent composed of a hydrocarbon structure.

A "heterocycle" is a ring structure containing heteroatoms such as O, S, and N as ring-forming atoms, and aromatic rings are called "heteroaromatic rings."

In addition, in this specification, "(meth)acrylic" means "acrylic" and "methacrylic". "(meth)acryloyl group" means "acryloyl group" and "methacryloyl group". "Alkali-soluble" means that it is soluble or swellable in a 2.38% by mass aqueous solution of tetramethylammonium hydroxide at 25°C.

[A] Polymer Having a Partial Structure Represented by Formula (1) First, each symbol in the polymer having a partial structure represented by formula (1) (hereinafter also referred to as “polymer [A]”) will be described.
In formula (1), the aromatic ring represented by Ar ¹ may be a monocyclic or condensed ring, an aromatic hydrocarbon ring, or an aromatic heterocyclic ring, but an aromatic hydrocarbon ring is preferred. Examples of the aromatic hydrocarbon ring include a monocyclic aromatic hydrocarbon ring and a condensed polycyclic aromatic hydrocarbon ring. Examples of the monocyclic aromatic hydrocarbon ring include a benzene ring. Examples of the condensed polycyclic aromatic hydrocarbon ring include a condensed bicyclic aromatic hydrocarbon ring having 8 to 20 carbon atoms (preferably a condensed bicyclic aromatic hydrocarbon ring having 10 to 16 carbon atoms) such as an indene ring, a naphthalene ring, or a tetralin ring, a condensed bicyclic aromatic hydrocarbon ring having 8 to 20 carbon atoms (preferably a condensed bicyclic aromatic hydrocarbon ring having 10 to 16 carbon atoms), a condensed tricyclic aromatic hydrocarbon ring (anthracene ring, phenanthrene ring, an anthracene ring, a phenanthrene ring, etc.), a condensed tetracyclic hydrocarbon ring (pyrene ring, naphthacene ring, etc.), and a condensed bicyclic to tetracyclic aromatic hydrocarbon ring. Examples of preferred aromatic rings include at least a benzene ring and a naphthalene ring, and a benzene ring is particularly preferred because of its excellent solubility in solvents and alkali solubility. The two Ar ^1s at the 9-position of the fluorene may be the same or different rings. Furthermore, the substitution position of Ar ¹ at the 9-position of the fluorene is not particularly limited, and for example, the naphthyl group at the 9-position of the fluorene may be a 1-naphthyl group, a 2-naphthyl group, etc.

In the substituent represented by ^R1 , examples of the halogen atom include a fluorine atom, a chlorine atom, and a bromine atom. Examples of the hydrocarbon group include an alkyl group and an aryl group. The alkyl group may be linear or branched, and examples of the alkyl group include an alkyl group having 1 to 6 carbon atoms, such as a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, and a t-butyl group, with an alkyl group having 1 to 4 carbon atoms being preferred, and a methyl group being more preferred. Examples of the aryl group include an aryl group having 6 to 10 carbon atoms, such as a phenyl group.

When k is 2 or more, R ¹ may be the same or different. In addition, R ¹ substituted on the two benzene rings constituting the fluorene skeleton may be the same or different. In addition, the bonding position (substitution position) of R ¹ to the benzene ring constituting the fluorene skeleton is not particularly limited. The preferred substitution number k is 0 or 1, particularly 0. In addition, in the two benzene rings constituting the fluorene, the substitution number k may be the same or different.

In the substituent represented by ^R2 , examples of the hydrocarbon group include alkyl groups (e.g., alkyl groups having 1 to 20 carbon atoms, such as methyl, ethyl, propyl, isopropyl, butyl, s-butyl, and t-butyl), cycloalkyl groups (cycloalkyl groups having 5 to 10 carbon atoms, such as cyclopentyl and cyclohexyl), aryl groups [e.g., phenyl, alkylphenyl groups (methylphenyl (tolyl), 2-methylphenyl, 3-methylphenyl, and dimethylphenyl (xylyl)), aryl groups having 6 to 10 carbon atoms, such as naphthyl], and aralkyl groups (aryl groups having 6 to 10 carbon atoms, such as benzyl and phenethyl, and alkyl groups having 1 to 4 carbon atoms).
The alkoxy group may be linear or branched, and examples thereof include alkoxy groups having 1 to 20 carbon atoms, such as a methoxy group, an ethoxy group, a propoxy group, and a butoxy group.
Examples of the cycloalkoxy group include cycloalkyloxy groups having 5 to 10 carbon atoms, such as a cyclohexyloxy group.
The aryloxy group includes, for example, aryloxy groups having 6 to 10 carbon atoms, such as a phenoxy group.
Examples of the aralkyloxy group include an alkyloxy group having 1 to 4 carbon atoms which has an aryl group having 6 to 10 carbon atoms, such as a benzyloxy group.
The alkylthio group may be linear or branched, and examples thereof include alkylthio groups having 1 to 20 carbon atoms, such as methylthio, ethylthio, propylthio, n-butylthio, and t-butylthio.
Examples of the cycloalkylthio group include cycloalkylthio groups having 5 to 10 carbon atoms, such as a cyclohexylthio group.
The arylthio group includes, for example, an arylthio group having 6 to 10 carbon atoms, such as a thiophenoxy group.
Examples of the aralkylthio group include thioether groups such as alkylthio groups having 1 to 4 carbon atoms which have an aryl group having 6 to 10 carbon atoms, such as a benzylthio group.
Examples of the acyl group include acyl groups having 1 to 6 carbon atoms, such as an acetyl group.
Examples of halogen atoms include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.
The substituted amino group includes, for example, a dialkylamino group.

R ² is preferably a hydrocarbon group, an alkoxy group, a cycloalkoxy group, an aryloxy group, an aralkyloxy group, an acyl group, a halogen atom, a nitro group, a cyano group, or a substituted amino group, and particularly preferably R ² is a hydrocarbon group [e.g., an alkyl group (e.g., an alkyl group having 1 to 6 carbon atoms)], an alkoxy group (e.g., an alkoxy group having 1 to 4 carbon atoms), a halogen atom (e.g., a fluorine atom, a chlorine atom, a bromine atom, an iodine atom), etc. When Ar ¹ is a benzene ring, R ² may be a group selected from an alkyl group having 1 to 4 carbon atoms, an aryl group, and a halogen atom.

In addition, in one Ar ¹ , when m is plural (2 or more), R ² may be different from each other or may be the same. In addition, in two Ar ¹ , R ² may be the same from each other or may be different. Furthermore, the preferred number of substitutions m may be 0 to 8, preferably 0 to 6 (e.g., 1 to 5), more preferably 0 to 4, particularly 0 to 2 (e.g., 0 or 1). In addition, in two Ar ¹ , the number of substitutions m may be the same or different from each other.

A is an alkylene group. Examples of the alkylene group include linear or branched alkylene groups having 2 to 10 carbon atoms, such as ethylene, propylene, propylidene, trimethylene, and tetramethylene. Of these, alkylene groups having 2 to 4 carbon atoms, such as ethylene and propylene, are preferred.

The repeat number n of the oxyalkylene group is an integer of 0 or more, and is usually about 0 to 10, preferably 0 to 5, more preferably 0 to 3, and particularly preferably 0 to 2.

X represents an oxygen atom or a sulfur atom, preferably an oxygen atom.

Ar ² represents an aromatic ring or a heterocycle, and examples of the aromatic ring include the same as those of Ar ^1. The heterocycle may be a monocyclic heterocycle or a polycyclic heterocycle, or may be an alicyclic heterocycle or an aromatic heterocycle. Examples of the heterocycle include a 3- to 20-membered heterocycle containing 1 to 5 heteroatoms selected from an oxygen atom, a nitrogen atom, and a sulfur atom. Examples of the alicyclic heterocycle include a 5- to 8-membered monocyclic alicyclic heterocycle such as a pyrrolidine ring, a piperidine ring, a piperazine ring, a morpholine ring, a thiomorpholine ring, a homopiperidine ring, and a homopiperazine ring. Examples of the aromatic heterocycle include a 5- or 6-membered monocyclic aromatic heterocycle such as a pyrrole ring, a pyrazole ring, an imidazole ring, a triazole ring, a pyridine ring, a pyrimidine ring, a thiophene ring, a furan ring, a thiazole ring, and an oxazole ring. Examples of the polycyclic heterocycle include a bicyclic or tricyclic heterocycle formed by condensing two or three monocyclic heterocycles together, or a monocyclic heterocycle and one or two aromatic hydrocarbon rings (e.g., a benzene ring, a naphthalene ring, etc.) together. Among these, ^Ar2 is preferably a monocyclic aromatic hydrocarbon ring or a condensed polycyclic aromatic hydrocarbon ring.

^R3 represents an alkali-soluble group. Examples of the alkali-soluble group include a hydroxyl group, a carboxyl group, a sulfonic acid group, a sulfonamide group, a sulfonylimide group, and a phosphonic acid group, and the like. The hydroxyl group and the carboxyl group are preferred, and the hydroxyl group is more preferred.
The number of alkali-soluble groups represented by 1 is an integer of 0 or more, preferably 1 to 3, and more preferably 1. The bonding position of the hydroxyl group is preferably the 2nd position, with the carbon atom in ^Ar2 to which the carbonyl group in formula (1) is bonded being the 1st position.

Ar ³ represents a tetravalent organic group, and examples thereof include tetravalent hydrocarbon groups. The tetravalent hydrocarbon group is preferably a linear or branched hydrocarbon chain having 2 to 10 carbon atoms, or a group in which four hydrogen atoms have been removed from a hydrocarbon ring. The number of carbon atoms in the hydrocarbon chain is preferably 3 to 8, more preferably 4 to 6. Examples of the hydrocarbon ring include an aromatic hydrocarbon ring and an aliphatic hydrocarbon ring, and the hydrocarbon ring may be linked by a divalent group containing a heteroatom, or an alkanediyl group such as a methylene group or an ethylene group. Examples of the aromatic hydrocarbon ring include the monocyclic aromatic hydrocarbon ring and the condensed polycyclic aromatic hydrocarbon ring described in Ar ¹ , as well as non-condensed polycyclic aromatic hydrocarbon rings (bisphenylfluorene, biphenyl, diphenyl ether, diphenyl thioether, diphenyl sulfone, benzophenone, diphenylmethane, and diphenylpropane). Examples of the aliphatic hydrocarbon ring include rings obtained by hydrogenating the aromatic hydrocarbon ring, such as saturated aliphatic hydrocarbon rings (e.g., cycloalkanes having 3 to 10 carbon atoms, such as cyclobutane, cyclopentane, cyclohexane, and cycloheptane), and unsaturated aliphatic hydrocarbon rings (e.g., cycloalkenes having 4 to 10 carbon atoms, such as cyclohexene). Specific examples include the following tetravalent hydrocarbon groups. In the formula, "*" indicates a bond.

Of these, in consideration of the balance between solubility in a solvent and increasing the refractive index, Ar ³ is preferably a group in which four hydrogen atoms have been removed from a non-condensed polycyclic aromatic hydrocarbon ring, a monocyclic aromatic hydrocarbon ring, or a linear or branched hydrocarbon chain having 2 to 10 carbon atoms, more preferably a group in which four hydrogen atoms have been removed from a non-condensed polycyclic aromatic hydrocarbon ring or a monocyclic aromatic hydrocarbon ring, and even more preferably a group in which four hydrogen atoms have been removed from biphenyl.

The weight-average molecular weight of the polymer having the partial structure represented by formula (1), as measured by gel permeation chromatography (standard resin: polystyrene), is preferably 700 to 10,000, more preferably 800 to 7,000, and even more preferably 1,000 to 5,000. If the molecular weight is too large, the viscosity increases, the handling property decreases, and the polymer becomes difficult to dissolve during alkaline development. Conversely, if the molecular weight is too small, the patterning characteristics and patterning stability become insufficient.

[A] Method for producing polymer
The polymer (A) can be produced by reacting a fluorene-containing compound represented by formula (2) with a tetracarboxylic dianhydride represented by formula (3).

The definitions and preferred embodiments of each symbol in formula (2) and formula (3) are as explained in formula (1).

The fluorene-containing compound represented by formula (2) can be produced, for example, by reacting an epoxy compound having a 9,9-bis(condensed polycyclic aryl)fluorene skeleton with an aromatic carboxylic acid.

The epoxy compound may be an epoxy compound corresponding to the fluorene-containing compound represented by formula (2), such as 9,9-bis(glycidyloxynaphthyl)fluorene [e.g., 9,9-bis(6-glycidyloxy-2-naphthyl)fluorene, 9,9-bis(5-glycidyloxy-1-naphthyl)fluorene, etc.].

Specific examples of preferred aromatic carboxylic acids include the compounds shown below.

In the reaction between the epoxy compound and the aromatic carboxylic acid, the aromatic carboxylic acid is used in a ratio of about 2 moles (1.8 to 2.2 moles) per mole of the epoxy compound.

The reaction may be carried out in the presence of a catalyst, and as the catalyst, a conventional acid catalyst or a conventional basic catalyst can be preferably used. Examples of the basic catalyst include aliphatic amines (trialkylamines such as trimethylamine, methyldimethylamine, triethylamine, tripropylamine, and triisopropylamine, alkanolamines such as triethanolamine and dimethylaminoethanol, etc.), alicyclic amines (cyclopentylamine, cyclohexylamine, etc.), aromatic amines (aniline, diethylaniline, etc.), heterocyclic amines (4-dimethylaminopyridine, morpholine, piperidine, etc.), quaternary ammonium salts (tetraalkylammonium halides such as tetraethylammonium chloride, tetraethylammonium bromide, tetrabutylammonium chloride, and tetrabutylammonium bromide, benzyltrialkylammonium halides such as benzyltrimethylammonium chloride, etc.), and metal alkoxides (e.g., potassium t-butoxide, etc.). These basic catalysts can be used alone or in combination of two or more.
Furthermore, phosphorus-based catalysts can also be used, and examples of the phosphorus-based catalyst include triphenylphosphine.

The amount of catalyst used can be adjusted depending on the type of catalyst, and may be, for example, about 0.001 to 15 parts by mass, preferably 0.01 to 10 parts by mass, and more preferably about 0.01 to 1 part by mass, relative to 100 parts by mass of the epoxy compound.

The reaction between the epoxy compound and the aromatic carboxylic acid may be carried out without a solvent, but may also be carried out in a solvent in terms of reactivity. The solvent is not particularly limited as long as it is inactive or non-reactive with the epoxy compound, etc., and examples of the solvent include hydrocarbons (toluene, xylene, etc.), halogen-based solvents (methylene chloride, chloroform, etc.), alcohols (ethanol, isopropanol, etc.), ethers (dialkyl ethers such as diethyl ether, cyclic ethers such as tetrahydrofuran, etc.), ketones (acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclopentanone, cyclohexanone, etc.), esters (methyl acetate, ethyl acetate, butyl acetate, etc.), cellosolves (methyl cellosolve, ethyl cellosolve, Examples of suitable solvents include alkyl cellosolves having 1 to 4 carbon atoms, such as butyl cellosolve, propylene glycol monomethyl ether such as propylene glycol monoalkyl ether having 1 to 4 carbon atoms, cellosolve acetates (alkyl cellosolve acetates having 1 to 4 carbon atoms, such as ethyl cellosolve acetate, propylene glycol monoalkyl ether acetate having 1 to 4 carbon atoms, such as propylene glycol monomethyl ether acetate), and carbitols (alkyl carbitols having 1 to 4 carbon atoms, such as methyl carbitol, ethyl carbitol, propyl carbitol, and butyl carbitol). These solvents can be used alone or in combination of two or more. Among these solvents, cellosolves and cellosolve acetates (for example, propylene glycol monoalkyl ether acetates having 1 to 4 carbon atoms, such as propylene glycol monomethyl ether acetate) are commonly used.

The amount of the solvent used may be, for example, about 50 to 2000 parts by mass, preferably 100 to 1000 parts by mass, more preferably 100 to 500 parts by mass, and particularly preferably about 100 to 200 parts by mass, relative to 100 parts by mass of the total amount of the epoxy compound and aromatic carboxylic acid.

The reaction temperature and reaction time can be appropriately selected depending on the type of raw material used. The reaction temperature may be, for example, usually 20 to 200°C, preferably 50 to 180°C, and more preferably about 100 to 150°C. The reaction time may be, for example, usually 30 minutes to 48 hours, preferably 1 to 36 hours, and more preferably about 2 to 24 hours. The reaction may be carried out in an inert atmosphere (such as an atmosphere of nitrogen, helium, or argon).

The tetracarboxylic dianhydride represented by formula (3) may be, for example, arene tetracarboxylic acids (e.g., tetracarboxylic acids having arenes with 6 to 20 carbon atoms, such as pyromellitic acid and naphthalene tetracarboxylic acid); diaryl tetracarboxylic acids [e.g., biphenyl tetracarboxylic acids (3,3',4,4'-biphenyl tetracarboxylic acid, etc.) and other aryl tetracarboxylic acids with 6 to 10 carbon atoms]; bis(dicarboxyaryl)alkanes [e.g., bis(dicarboxyaryl)alkanes with 6 to 10 carbon atoms, such as 3,3',4,4'-tetracarboxydiphenylmethane and 2,2'-bis(3,4-dicarboxyphenyl)propane]. lecan, etc.); bis(dicarboxyaryl) ethers [e.g., bis(aryl) ethers having 6 to 10 dicarboxy carbon atoms, such as 4,4'-oxydiphthalic acid, etc.]; bis(dicarboxyaryl) ketones [e.g., bis(aryl) ketones having 6 to 10 dicarboxy carbon atoms, such as 3,3',4,4'-benzophenonetetracarboxylic acid, etc.]; bis(dicarboxyaryl) sulfones [e.g., bis(aryl) sulfones having 6 to 10 dicarboxy carbon atoms, such as 3,3',4,4'-diphenylsulfonetetracarboxylic acid, etc.], etc., dianhydrides of aromatic tetracarboxylic acids, such as hydrogenated dianhydrides of these aromatic tetracarboxylic acids, etc.

In addition, tetrabasic acid anhydrides having a tetravalent group with an aliphatic or alicyclic skeleton can also be used. Specifically, 1,2,3,4-butanetetracarboxylic acid dianhydride, 1,2,3,4-cyclobutanetetracarboxylic acid dianhydride, 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic acid dianhydride, 1,2,3,4-tetramethyl-1,2,3,4-cyclobutanetetracarboxylic acid dianhydride, 2,3,5-tricarboxycyclopentylacetic acid dianhydride, 5-(2,5-dioxotetrahydrofuran-3-yl)-3a,4,5, Examples include 9b-tetrahydronaphtho[1,2-c]furan-1,3-dione, 5-(2,5-dioxotetrahydrofuran-3-yl)-8-methyl-3a,4,5,9b-tetrahydronaphtho[1,2-c]furan-1,3-dione, 2,4,6,8-tetracarboxybicyclo[3.3.0]octane-2:4,6:8-dianhydride, cyclopentane tetracarboxylic dianhydride, and cyclohexane tetracarboxylic dianhydride.

In the reaction of the fluorene-containing compound represented by formula (2) with the tetracarboxylic dianhydride represented by formula (3), the ratio of the tetracarboxylic dianhydride is about 0.8 to 1.2 moles per 1.8 moles of the fluorene-containing compound.

The reaction between the fluorene-containing compound and the tetracarboxylic dianhydride may be carried out without a solvent, but may also be carried out in a solvent in terms of reactivity, etc. The solvent may be selected from the solvents used in the production of the epoxy compound, and the same solvent as that used in the production of the epoxy compound is usually used.

The amount of the solvent used may be, for example, usually 10 to 2000 parts by mass, preferably 50 to 1000 parts by mass, more preferably 100 to 300 parts by mass, and particularly preferably about 100 to 200 parts by mass, relative to 100 parts by mass of the total amount of the fluorene-containing compound and the tetracarboxylic dianhydride.

The reaction temperature and reaction time can be appropriately selected depending on the type of raw material used. The reaction temperature may be, for example, usually 20 to 200°C, preferably 50 to 180°C, and more preferably about 100 to 150°C. The reaction time may be, for example, usually 30 minutes to 48 hours, preferably 1 to 36 hours, and more preferably about 2 to 24 hours. The reaction may be carried out in an inert atmosphere (such as an atmosphere of nitrogen, helium, or argon).

[A] The polymer may be an acid anhydride-modified polymer in which the hydroxyl groups at the terminals are blocked with dicarboxylic anhydride. By blocking the terminal hydroxyl groups with dicarboxylic anhydride, the molecular weight can be adjusted, gel formation can be suppressed, and handling can be improved.

Examples of dicarboxylic acid anhydrides include saturated aliphatic dicarboxylic anhydrides such as succinic anhydride, unsaturated aliphatic dicarboxylic anhydrides such as itaconic anhydride, maleic anhydride, and fumaric anhydride, saturated alicyclic dicarboxylic anhydrides such as tetrahydrophthalic anhydride, unsaturated alicyclic dicarboxylic anhydrides such as hexahydrophthalic anhydride, and aromatic dicarboxylic anhydrides such as phthalic anhydride. These dicarboxylic acid anhydrides can be used alone or in combination of two or more.

[B] Polymerization initiator The polymerization initiator used in the present invention is preferably a photopolymerization initiator. As the photopolymerization initiator, a photoradical polymerization initiator that generates radicals in response to radiation and can initiate polymerization can be preferably used. The photopolymerization initiator used is not particularly limited. Examples of the photopolymerization initiator include O-acyloxime compounds, acetophenone compounds, biimidazole compounds, and acylphosphine oxide compounds.

Examples of O-acyloxime compounds include 1,2-octanedione 1-[4-(phenylthio)-2-(O-benzoyloxime)], ethanone-1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]-1-(O-acetyloxime), 1-(9-ethyl-6-benzoyl-9.H.-carbazol-3-yl)-octan-1-one oxime-O-acetate, 1-[9-ethyl-6-(2-methylbenzoyl)-9.H.-carbazol-3-yl]-ethan-1-one oxime-O-benzoate, 1-[9-n-butyl-6-(2-ethylbenzoyl)-9.H. -carbazol-3-yl]-ethan-1-one oxime-O-benzoate, ethanone-1-[9-ethyl-6-(2-methyl-4-tetrahydrofuranylbenzoyl)-9.H.-carbazol-3-yl]-1-(O-acetyloxime), ethanone-1-[9-ethyl-6-(2-methyl-4-tetrahydropyranylbenzoyl)-9.H.-carbazol-3-yl]-1-(O-acetyloxime), ethanone-1-[9-ethyl-6-(2-methyl-5-tetrahydrofuranylbenzoyl)-9.H.-carbazol-3-yl]-1-(O-acetyloxime), ethanone-1-[9-ethyl-6-{2-methyl-4-(2,2-dimethyl-1,3-dioxolanyl)methoxybenzoyl}-9.H. -carbazol-3-yl]-1-(O-acetyloxime), etc.

Examples of acetophenone compounds include α-aminoketone compounds and α-hydroxyketone compounds. Specific examples of these include α-aminoketone compounds such as 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butanone, 2-dimethylamino-2-(4-methylbenzyl)-1-(4-morpholin-4-yl-phenyl)-butan-1-one, and 2-methyl-1-(4-methylthiophenyl)-2-morpholinopropan-1-one. Examples of α-hydroxyketone compounds include 1-phenyl-2-hydroxy-2-methylpropan-1-one, 1-(4-i-propylphenyl)-2-hydroxy-2-methylpropan-1-one, 4-(2-hydroxyethoxy)phenyl-(2-hydroxy-2-propyl)ketone, and 1-hydroxycyclohexylphenylketone.

Examples of 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, and 2,2'-bis(2,4,6-trichlorophenyl)-4,4',5,5'-tetraphenyl-1,2'-biimidazole.

Examples of acylphosphine oxide compounds include 2,4,6-trimethylbenzoyl-diphenylphosphine oxide and phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide.

The content of the photopolymerization initiator in the composition is preferably 0.5 parts by mass or more, and more preferably 1 part by mass or more, relative to 100 parts by mass of the total amount of the polymerizable compounds [C] contained in the composition. The content of the photopolymerization initiator is preferably 20 parts by mass or less, more preferably 18 parts by mass or less, and even more preferably 15 parts by mass or less, relative to 100 parts by mass of the total amount of the polymerizable compounds contained in the composition. By setting the content of the photopolymerization initiator within the above range, it is possible to obtain a cured product that has excellent patterning characteristics and patterning margins, a high refractive index, and reduced outgassing.

[C] Polymerizable Compound From the viewpoint of lowering the temperature during thermal flow as much as possible, the molecular weight of the polymerizable compound [C] is preferably smaller than that of the polymer [A]. Specifically, the molecular weight of the polymerizable compound [C] is preferably less than 600, more preferably 550 or less, even more preferably 500 or less, and particularly preferably 450 or less. In addition, from the viewpoint of obtaining a cured product having excellent patterning characteristics and patterning margin, a high refractive index, and reduced outgassing, the molecular weight of the polymerizable compound [C] is preferably 100 or more.

The polymerizable compound [C] used in the present invention is preferably a compound having a polymerizable carbon-carbon unsaturated bond. The polymerizable compound [C] may be either a monofunctional compound (hereinafter also referred to as "compound (C1)") or a polyfunctional compound (hereinafter also referred to as "compound (C2)"), and these may be used in combination.
Examples of the compound (C1) include (meth)acrylic acid esters having a chain structure, (meth)acrylic acid esters having an alicyclic structure, (meth)acrylic acid esters having an aromatic ring structure, (meth)acrylamide compounds, chain vinyl compounds, aromatic vinyl compounds, maleimide compounds, etc. These compounds are preferably used because they have good copolymerizability with the polymer [A] and relatively high plasticity. Among them, (meth)acrylic acid ester compounds which are at least one selected from the group consisting of (meth)acrylic acid esters having a chain structure, (meth)acrylic acid esters having an alicyclic structure, and (meth)acrylic acid esters having an aromatic ring structure are more preferably used.

Examples of (meth)acrylic acid esters having a chain structure include (meth)acrylic acid alkyl esters, (meth)acrylic acid hydroxyalkyl esters, (meth)acrylic acid alkoxyalkyl esters, and (meth)acrylic acid polyoxyalkylene esters. Examples of (meth)acrylic acid alkyl esters include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, n-lauryl (meth)acrylate, and n-stearyl (meth)acrylate. Examples of (meth)acrylic acid hydroxyalkyl esters include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, and 4-hydroxybutyl (meth)acrylate. Examples of (meth)acrylic acid alkoxyalkyl esters include methoxyethyl (meth)acrylate, ethoxyethyl (meth)acrylate, and propoxyethyl (meth)acrylate. Examples of (meth)acrylic acid polyoxyalkylene esters include methoxydiethylene glycol (meth)acrylate, methoxytetraethylene glycol (meth)acrylate, ethoxydiethylene glycol (meth)acrylate, methoxydipropylene glycol (meth)acrylate, ethoxydipropylene glycol (meth)acrylate, and 2-ethylhexyloxydiethylene glycol (meth)acrylate.

Examples of (meth)acrylic acid esters having an alicyclic structure include cyclohexyl (meth)acrylate, 2-methylcyclohexyl (meth)acrylate, 4-butylcyclohexyl (meth)acrylate, 4-hydroxymethylcyclohexyl (meth)acrylate, tricyclo[5.2.1.0 ^2,6 ]decan-8-yl (meth)acrylate, tricyclo[5.2.1.0 ^2,5 ]decan-8-yloxyethyl (meth)acrylate, and isobornyl (meth)acrylate.
Examples of the (meth)acrylic acid ester having an aromatic ring structure include phenyl (meth)acrylate, benzyl (meth)acrylate, naphthylmethyl (meth)acrylate, naphthylethyl (meth)acrylate, phenoxyethyl (meth)acrylate, phenylthioethyl (meth)acrylate, m-phenoxyphenylmethyl (meth)acrylate, p-phenoxyphenylmethyl (meth)acrylate, o-phenylphenoxyethyl (meth)acrylate, 2-hydroxy-3-phenoxypropyl (meth)acrylate, polyethyleneoxynonylphenyl (meth)acrylate, (1-naphthyl)methyl (meth)acrylate, (2-naphthyl)methyl (meth)acrylate, and (1,1'-biphenyl-4-yl)methyl (meth)acrylate.

Examples of the (meth)acrylamide compound include (meth)acryloylmorpholine, N-(2-hydroxyethyl)(meth)acrylamide, N-vinyl-2-pyrrolidone, and N-vinyl-ε-caprolactam.
Examples of the chain vinyl compound include propene, butene, pentene, and hexene.
Examples of the aromatic vinyl compound include styrene, methylstyrene, α-methylstyrene, t-butoxystyrene, and vinylnaphthalene.
Examples of the maleimide compound include N-methylmaleimide, N-cyclohexylmaleimide, N-phenylmaleimide, and N-(p-methylphenyl)maleimide.

Specific preferred examples of compound (C1) include compounds represented by the following formulas (C1-1) to (C1-28).

(In formulas (C1-1) to (C1-28), R ²⁰ is a hydrogen atom or a methyl group. Each p is independently an integer of 0 to 3.)

Examples of the compound (C2) include polyfunctional (meth)acrylic acid esters, polyfunctional aromatic vinyl compounds, and polyfunctional chain vinyl compounds.
Examples of polyfunctional (meth)acrylic acid esters include bifunctional (meth)acrylic acid esters, trifunctional or higher (meth)acrylic acid esters, etc. Specific examples of these include bifunctional (meth)acrylic acid esters such as ethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, 1,10-decanediol di(meth)acrylate, diethylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, etc.

Examples of trifunctional or higher (meth)acrylic acid esters include trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, ethylene oxide-modified dipentaerythritol hexa(meth)acrylate, tri(2-(meth)acryloyloxyethyl)phosphate, succinic acid-modified pentaerythritol tri( Examples include polyfunctional urethane acrylate compounds obtained by reacting a compound having a linear alkylene group and an alicyclic structure and having two or more isocyanate groups with a compound having one or more hydroxyl groups in the molecule and having three, four or five (meth)acryloyloxy groups, as well as succinic acid-modified dipentaerythritol penta(meth)acrylate, tris(2-(meth)acryloyloxyethyl) isocyanurate, and carboxyl group-containing polybasic acid-modified (meth)acrylic oligomers.

Examples of the polyfunctional aromatic vinyl compound include 1,3-divinylbenzene and 1,4-divinylbenzene.
Examples of the polyfunctional chain vinyl compound include 1,5-hexadiene, 1,6-heptadiene, and 1,7-octadiene.

Specific preferred examples of compound (C2) include compounds represented by the following formulas (C2-1) to (C2-19).

(In formulas (C2-1) to (C2-19), R ²⁰ is a hydrogen atom or a methyl group. x, y, and z each independently represent an integer of 0 to 3, provided that 1≦x+y+z≦3 is satisfied.)

The content of compound (C1) is preferably 5 parts by mass or more, more preferably 10 parts by mass or more, per 100 parts by mass of the total amount of polymer [A] contained in the composition, from the viewpoint of obtaining a cured product with excellent patterning characteristics and patterning margin, a high refractive index, and reduced outgassing while enabling the formation of an appropriate lens shape by thermal flow at low temperatures. Also, from the viewpoint of obtaining a cured product with excellent patterning characteristics and patterning margin, suppressing a decrease in the refractive index of the obtained cured product, and reducing outgassing, the content of compound (C) is preferably 100 parts by mass or less, more preferably 50 parts by mass or less, per 100 parts by mass of the total amount of polymer [A] contained in the composition.

The content of compound (C2) is preferably 5 parts by mass or more, more preferably 10 parts by mass or more, per 100 parts by mass of the total amount of polymer [A] contained in the composition, from the viewpoint of fluidizing the pattern at low temperatures (for example, a temperature of 100°C or less), obtaining a cured product with excellent patterning characteristics and patterning margin, a high refractive index, and reduced outgassing. Also, from the viewpoint of obtaining a cured product with excellent patterning characteristics and patterning margin, suppressing a decrease in the refractive index of the obtained cured product, and reduced outgassing, the content of compound (C2) is preferably 100 parts by mass or less, more preferably 50 parts by mass or less, and even more preferably 30 parts by mass or less, per 100 parts by mass of the total amount of polymer [A] contained in the composition.

As the polymerizable compound [C], from the viewpoint of obtaining a cured product having excellent patterning properties and patterning margins, a higher refractive index, and reduced outgassing while allowing the formation of an appropriate lens shape by thermal flow at low temperatures, it is preferable to use a combination of compound (C1) and compound (C2). The compound (C1) is contained in an amount of 5 parts by mass or more and 100 parts by mass or less relative to 100 parts by mass of the total amount of the polymer [A], and the compound (C2) is contained in an amount of preferably 10% by mass or more, more preferably 25% by mass or more, and even more preferably 30% by mass or more relative to the total amount of compound (C1), which is suitable in that a cured product having high heat resistance can be obtained while forming an appropriate lens shape by thermal flow at low temperatures. In addition, the content of compound (C2) is preferably 95% by mass or less, more preferably 90% by mass or less, relative to the total amount of compound (C1) contained in the composition, from the viewpoint of obtaining a cured product having excellent patterning properties and patterning margins, a higher refractive index, and reduced outgassing.

<Other ingredients>
In addition to the above-mentioned polymer [A], photopolymerization initiator [B], and polymerizable compound [C], the present composition may further contain other components (hereinafter also referred to as "other components"). Examples of the other components include a polymer having a weight average molecular weight of 2,000 to 100,000, a solvent, etc. The weight average molecular weight is a value measured using gel permeation chromatography (reference resin: polystyrene).

Component (D): Polymer having a weight-average molecular weight of 2,000 or more and 100,000 or less The present composition may further contain, as an additive component, a polymer having a weight-average molecular weight of 2,000 or more and 100,000 or less (hereinafter also referred to as “polymer (D)”) other than the polymer [A].

Examples of the polymer (D) include an alkali-soluble polymer, a fluorene skeleton-containing photosensitive polymer, a carboxy group-containing photosensitive polymer, etc. Examples of the alkali-soluble polymer include a (meth)acrylic acid/methyl (meth)acrylate copolymer, a (meth)acrylic acid/benzyl (meth)acrylate copolymer, a (meth)acrylic acid/2-hydroxyethyl (meth)acrylate/benzyl (meth)acrylate copolymer, a (meth)acrylic acid/styrene/isoprene/tricyclodecanyl (meth)acrylate/2-mono(hexahydroxyphthaloyloxy)ethyl (meth)acrylate copolymer, a methacrylic-modified acrylic resin, and an acid anhydride-modified acrylic resin.

Examples of photosensitive polymers containing fluorene skeletons include those described in International Publication No. 2009/119622. Examples of photosensitive polymers containing carboxyl groups include acid-modified epoxy acrylates such as bisphenol A type epoxy acrylate, bisphenol F type epoxy acrylate, cresol novolac type epoxy acrylate, cresol novolac type epoxy acrylate, and biphenyl type epoxy acrylate. Specific examples of photosensitive polymers containing carboxyl groups include CCR-1235, CCR-1291H, ZAR-1035, ZAR-2000, ZFR-1401H, ZFR-1491H, ZCR-1569H, and ZCR-1798H (all manufactured by Nippon Kayaku Co., Ltd.).

When polymer (D) is blended in the composition, the content of polymer (D) is preferably 50 parts by mass or less, and more preferably 20 parts by mass or less, per 100 parts by mass of the total amount of polymer [A] contained in the composition. By keeping the content of polymer (D) within the above range, it is possible to obtain an appropriate lens shape by thermal flow at low temperatures while obtaining an improved heat resistance effect.

Component (E): Solvent The present composition is a liquid composition in which the polymer (A), the photopolymerization initiator (B), the polymerizable compound (C), and other components blended as necessary are preferably dissolved or dispersed in a solvent. As the solvent, an organic solvent that dissolves each component blended in the present composition and does not react with each component is preferred.

Specific examples of the solvent include alcohols such as methanol, ethanol, isopropanol, butanol, and octanol; esters such as ethyl acetate, butyl acetate, ethyl lactate, γ-butyrolactone, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, methyl 3-methoxypropionate, and ethyl 3-ethoxypropionate; ethers such as ethylene glycol monobutyl ether, propylene glycol monomethyl ether, ethylene diglycol monomethyl ether, ethylene diglycol ethyl methyl ether, dimethylene glycol dimethyl ether, diethylene glycol dimethyl ether, and diethylene glycol ethyl methyl ether; amides such as dimethylformamide, N,N-dimethylacetamide, and N-methylpyrrolidone; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclopentanone, and cyclohexanone; and aromatic hydrocarbons such as benzene, toluene, xylene, and ethylbenzene. Of these, the solvent preferably contains at least one selected from the group consisting of ethers, esters, and ketones.

Other components include, in addition to those mentioned above, for example, polymerization inhibitors, surfactants, antioxidants, sensitizers, softeners, plasticizers, adhesive aids, ultraviolet absorbers, etc. The blending ratio of these components is appropriately selected according to each component within a range that does not impair the effects of the present disclosure.

For example, a surfactant can be used to improve the coating properties of the composition (wetting and spreading properties and reducing coating unevenness). Examples of surfactants include fluorine-based surfactants, silicone-based surfactants, and nonionic surfactants.

Specific examples of surfactants include fluorine-based surfactants, which are listed under the trade names below: Megafac F-171, F-172, F-173, F-251, F-430, F-554, F-563 (manufactured by DIC Corporation); Fluorad FC430, FC431 (manufactured by Sumitomo 3M); Asahi Guard AG710, Surflon S-382, SC-101, SC-102, SC-103, SC-104, SC-105, SC-106, S-611 (manufactured by AGC Seimi Chemical Co., Ltd.); Polyflow No. 75, No. 95 (Kyoeisha Chemical Co., Ltd.); FTX-218 (Neos Co., Ltd.); EFTOP EF301, EF303, and EF352 (Shin-Akita Kasei Co., Ltd.), etc.

Examples of silicone surfactants include, under the trade names below, SH200-100cs, SH-28PA, SH-30PA, SH-89PA, SH-190, SH-8400, FLUID, SH-193, SZ-6032, SF-8428, DC-57, DC-190, PAINTAD19, FZ-2101, FZ-77, FZ-2118, L-7001, and L-7002 (manufactured by Dow Corning Toray Silicone Co., Ltd.); organosiloxane polymer KP341 (manufactured by Shin-Etsu Chemical Co., Ltd.); and BYK-300, 306, 310, 330, 335, 341, 344, 370, 340, and 345 (manufactured by BYK Japan).

Examples of nonionic surfactants include polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene oleyl ether, polyoxyethylene n-octylphenyl ether, polyoxyethylene n-nonylphenyl ether, polyethylene glycol dilaurate, and polyethylene glycol distearate.

When a surfactant is blended in the composition, the content of the surfactant is preferably 0.01 to 1.5 parts by mass, more preferably 0.02 to 1.2 parts by mass, and even more preferably 0.05 to 1.0 parts by mass, per 100 parts by mass of the total amount of the polymer [A] contained in the composition.

The adhesion aid is a component that improves the adhesion between the cured product formed using the composition and the substrate, and suppresses peeling of the cured product during the development process. As the adhesion aid, a functional silane coupling agent having a reactive functional group can be preferably used. Examples of reactive functional groups that functional silane coupling agents have include carboxy groups, (meth)acryloyl groups, epoxy groups, vinyl groups, and isocyanate groups.

Specific examples of functional coupling agents include trimethoxysilylbenzoic acid, 3-glycidyloxypropyltrimethoxysilane, 3-glycidyloxypropyltriethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-(meth)acryloxypropyltrimethoxysilane, 3-(meth)acryloxypropyltriethoxysilane, vinyltriacetoxysilane, vinyltrimethoxysilane, and 3-isocyanatopropyltriethoxysilane.

When the composition contains an adhesive aid, the content thereof is preferably 0.01 parts by mass or more and 10 parts by mass or less, and more preferably 0.1 parts by mass or more and 5 parts by mass or less, relative to 100 parts by mass of the polymer [A] contained in the composition.

The solid content concentration of the present composition (i.e., the ratio of the total mass of the components other than the solvent in the radiation-sensitive composition to the total mass of the radiation-sensitive composition) is appropriately selected taking into consideration the viscosity, volatility, etc. The solid content concentration of the present composition is preferably in the range of 1 to 60 mass %. A solid content concentration of 1 mass % or more is preferable in that a sufficient thickness of the coating film can be ensured when the present composition is applied to a substrate. Also, a solid content concentration of 60 mass % or less is preferable in that the thickness of the coating film is not too large, and furthermore, the viscosity of the present composition can be appropriately increased, and good coatability can be ensured. The solid content concentration of the present composition is more preferably 5 to 50 mass %, and even more preferably 10 to 40 mass %.

[Lens manufacturing method]
A microlens can be manufactured by using the radiation-sensitive composition prepared as described above. This composition is particularly suitable as a negative pattern-forming material for exposing a part of an organic film formed from the radiation-sensitive composition to light, and dissolving the unexposed part of the exposed organic film in an alkaline developer to form a pattern (i.e., a cured product formed from the radiation-sensitive composition) in a lens shape by fluidizing it through a heat treatment. Each step (steps (I) to (IV)) in the method for manufacturing a microlens according to the present disclosure will be described below.

<Step (I): Coating step>
Step (I) is a step of forming a coating film on a substrate by applying the composition onto the substrate. Examples of the substrate include glass substrates, silicon wafers, plastic substrates, plastic films, and substrates having colored resists, overcoats, anti-reflection films, various metal thin films, sealing films, etc. formed on the surfaces thereof. Examples of the plastic substrates and plastic films include resin substrates and films made of plastics such as polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyethersulfone, polycarbonate, and polyimide. These substrates may be provided in advance with various elements (for example, light receiving elements such as photodiodes, light emitting elements such as organic light emitting diodes).

As a method for applying the present composition, for example, a suitable method such as a spray method, a roll coating method, a rotary coating method (spin coating method), a slit die coating method, a bar coating method, an inkjet method, etc. can be used. Of these, the spin coating method, the bar coating method, and the slit die coating method are preferred as application methods.

After the composition is applied to the substrate, the composition may be preheated (prebaked) to prevent dripping. The prebaking conditions can be set appropriately depending on the type and proportion of each component. The prebaking conditions can be, for example, 60 to 130°C for 30 seconds to 10 minutes. The thickness of the coating film formed after prebaking is preferably 0.1 to 20 μm, more preferably 0.2 to 15 μm.

<Step (II): Exposure Step>
Step (II) is a step of irradiating a part of the coating film formed in step (I) with radiation. This radiation irradiation causes a curing reaction in the exposed part, and a cured product is obtained in which the exposed part is cured. In step (II), the coating film is irradiated with radiation through a mask having a pattern (e.g., a dot pattern) for obtaining a microlens having a desired shape. The mask may be a multi-tone mask such as a halftone mask or a graytone mask.

Examples of the radiation to be irradiated to the coating film include ultraviolet rays, far ultraviolet rays, X-rays, charged particle beams, etc. Examples of ultraviolet rays include g-rays (wavelength 436 nm), i-rays (wavelength 365 nm), KrF excimer laser light (wavelength 248 nm), etc. Examples of X-rays include synchrotron radiation, etc. Examples of charged particle beams include electron beams, etc. Among these, the radiation to be irradiated to the coating film is preferably ultraviolet rays, and more preferably ultraviolet rays having a wavelength of 200 nm or more and 380 nm or less. Examples of the light source to be used include low pressure mercury lamps, high pressure mercury lamps, deuterium lamps, metal halide lamps, argon resonance lamps, xenon lamps, excimer lasers, etc. The radiation exposure is preferably 500 J/m ² to 50,000 J/m ² (50 to 500 mJ/cm ² ).

<Step (III): Development Step>
Step (III) is a step of forming a pattern on the substrate by developing the coating film irradiated with radiation in step (II). This development step removes the unexposed parts of the coating film formed on the substrate, and a pattern (more specifically, a concave-convex pattern formed by a large number of regularly arranged micro-cured products) in which the exposed parts remain can be formed on the substrate. The micro-cured products have, for example, a substantially rectangular cross section.

Examples of the developer include aqueous solutions of alkali (basic compounds). Examples of aqueous solutions of alkali include sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, ammonia, ethylamine, n-propylamine, diethylamine, diethylaminoethanol, di-n-propylamine, triethylamine, methyldiethylamine, dimethylethanolamine, triethanolamine, tetramethylammonium hydroxide (TMAH), tetraethylammonium hydroxide, pyrrole, piperidine, 1,8-diazabicyclo[5.4.0]-7-undecene, 1,5-diazabicyclo[4.3.0]-5-nonane, and the like. In addition, an aqueous solution obtained by adding an appropriate amount of a water-soluble organic solvent such as methanol or ethanol or a surfactant to an aqueous solution of alkali, or by adding a small amount of various organic solvents capable of dissolving the present composition, may be used as the developer.

As a development method, for example, a suitable method such as a puddle method, a dipping method, a rocking immersion method, a shower method, etc. can be used. The development time may be adjusted appropriately depending on the composition of the present composition. The development time is, for example, 20 to 120 seconds.

<Step (IV): Heating step>
Step (IV) is a step of heating the developed pattern and forming the micro-cured material on the substrate into a lens shape by thermal flow. The heat treatment in step (IV) causes the composition to further harden while thermally flowing a pattern of micro-cured material having a substantially rectangular cross section. This makes it possible to obtain a microlens array in which hemispherical micro-cured material is regularly arranged on the substrate. The heat treatment can be performed using a heating device such as an oven or a hot plate.

From the viewpoint of being applicable to high refractive index materials for organic electroluminescence elements, the heating temperature in step (IV) is preferably 100°C or less, more preferably 95°C or less, and even more preferably 90°C or less. From the viewpoint of obtaining microlenses with high heat resistance and chemical resistance and good shape, the heating temperature in step (IV) is preferably 60°C or more, more preferably 80°C or more. The heating time can be appropriately set depending on the type of heating device, etc. For example, when heating is performed using a hot plate, the heating time is, for example, 5 to 60 minutes. When heating is performed using an oven, the heating time is, for example, 10 to 90 minutes. In step (IV), a step bake method in which multiple heating processes are performed can also be used.

The production method of the present disclosure may further include the following step (V) as an optional step.
(V) A step of irradiating the lens obtained by the above step (IV) with radiation (hereinafter also referred to as a "post-exposure step").

<Step (V): Post-exposure step>
Step (V) is a step of further irradiating at least a part of the coating film after development with radiation. By irradiating with radiation in step (V) (hereinafter also referred to as "post-exposure"), the heat resistance, chemical resistance, etc. can be further improved, and a highly reliable cured product can be obtained. Specific examples of post-exposure include (1) a method of irradiating radiation to the coating film after the development step and before the heating step (i.e., the pattern before thermal flow), and (2) a method of irradiating radiation to the coating film after the heating step (i.e., the lens after thermal flow). Of these, from the viewpoint of suitably realizing thermal flow due to low temperature, the method (2), that is, irradiating radiation to the lens formed by heating the pattern, is preferred. The type of radiation and exposure conditions in the post-exposure can be the same as those in step (II). Note that the conditions such as the wavelength and dose of the irradiated light, and the light source during the post-exposure may be the same as or different from those in step (II).

The microlenses thus obtained have a good lens shape. The diameter of the microlenses is, for example, 1 μm or more and 100 μm or less. Furthermore, the microlenses obtained from the present composition have excellent heat resistance and chemical resistance, and are also highly transparent. Therefore, the microlenses of the present disclosure can be suitably used as microlenses for solid-state imaging elements provided in imaging devices such as cameras, and for various display elements such as organic EL elements and liquid crystal display elements. In particular, the present composition can form a lens shape even when thermal flow is performed at a low temperature of 100° C. or less. Therefore, it is particularly suitable for microlenses for the manufacture of organic EL elements, which require the application of low-temperature processes.

<Cured film, display device, solid-state imaging element, imaging device>
The cured film of the present disclosure is obtained by curing a radiation-sensitive composition containing the above-mentioned [A] polymer, [B] photopolymerization initiator, and [C] polymerizable compound. As described above, the radiation-sensitive composition has excellent patterning properties and patterning margins, and the cured product formed by the radiation-sensitive composition has a high refractive index and reduced outgassing. In addition, by heating the developed pattern at a low temperature, a cured film with sufficient thermal flow and excellent surface flatness can be obtained. Therefore, the radiation-sensitive composition of the present disclosure is suitable as a composition for forming a flattening film provided on a display device or a solid-state imaging device. The above explanation applies to the type and content of the polymer [A], the photopolymerization initiator [B], and the polymerizable compound [C] contained in the radiation-sensitive composition for forming a flattening film, and each component that is optionally blended.
Examples of the display element include an organic EL element, a liquid crystal display element, electronic paper, etc., and examples of the solid-state imaging element include a CCD image sensor, a CMOS image sensor, etc. By using such a display element or solid-state imaging element, a display device or an imaging device including these elements can be obtained.
The cured film such as the planarizing film can be produced by a method including steps (I) to (IV) in the same manner as the above-mentioned method for producing a lens. This method may further include the above-mentioned step (V).

The radiation-sensitive composition of the present disclosure described above is applied onto a substrate, and pre-heated (pre-baked) at 85° C. for 2 minutes to obtain a coating film with a thickness of 9.0 μm, which is then irradiated with radiation of 400 mJ/cm ² in terms of i-line radiation, and then heated (post-baked) at 100° C. for 40 minutes to obtain a cured product with a refractive index of usually 1.64 or more. According to the radiation-sensitive composition of the present disclosure, a cured film with a high refractive index, preferably a refractive index of 1.66 or more, can also be obtained under the above conditions.

According to the present disclosure described above, the following means are provided.
[1] [A] a polymer having a partial structure represented by the following formula (1),
[B] a polymerization initiator,
[C] A radiation-sensitive composition comprising a polymerizable compound.
[2] The radiation-sensitive composition according to the above [1], wherein Ar ¹ is a benzene ring or a naphthalene ring.
[3] The radiation-sensitive composition according to the above [1] or [2], wherein Ar ² is a monocyclic aromatic hydrocarbon ring or a condensed polycyclic aromatic hydrocarbon ring.
[4] The radiation-sensitive composition according to any one of [1] to [3] above, wherein R ³ is a hydroxyl group.
[5] A cured product obtained by curing the radiation-sensitive composition according to any one of [1] to [4] above.
[6] A step of applying the radiation-sensitive composition according to any one of [1] to [4] above onto a substrate to form a coating film;
exposing a portion of the coating to radiation;
and developing the irradiated coating to form a pattern on the substrate.
[7] The method for manufacturing a lens according to [6] above, further comprising a step of heating the pattern to form a lens.
[8] The method for manufacturing a lens according to [7] above, wherein the temperature at which the pattern is heated is 100° C. or less.
[9] A display device comprising the cured product according to [5] above.
[10] A solid-state imaging device comprising the cured product according to [5] above.
[11] An imaging device comprising the solid-state imaging element according to [10].
[12] A polymer having a partial structure represented by the following formula (1):

(In formula (1),
^Ar1 represents an aromatic ring;
^Ar2 represents an aromatic ring or a heterocycle;
R ¹ represents a cyano group, a halogen atom, or a hydrocarbon group;
^R2 represents a hydrocarbon group, an alkoxy group, a cycloalkoxy group, an aryloxy group, an aralkyloxy group, an alkylthio group, a cycloalkylthio group, an arylthio group, an aralkylthio group, an acyl group, a halogen atom, a nitro group, a cyano group, or a substituted amino group;
^R3 represents an alkali-soluble group;
X represents an oxygen atom or a sulfur atom;
^Ar3 represents a tetravalent organic group;
A represents an alkylene group;
k represents an integer of 0 to 4;
l, m, and n each independently represent an integer of 0 or more.

The present invention will be described in detail below with reference to examples, but the present invention is not limited to the following examples. Note that "parts" and "%" in the examples and comparative examples are by weight unless otherwise specified.

Weight average molecular weight (Mw)
The weight average molecular weight (Mw) of the compound is a polystyrene-equivalent value measured by gel permeation chromatography (GPC) under the following conditions.
Column: TSKgel GRCXLII, manufactured by Tosoh Corporation
Solvent: Tetrahydrofuran Temperature: 40°C
Pressure: 68 kgf/ ^cm2

The compounds used in the examples and comparative examples and their abbreviations are as follows.
Solvent PGMEA: Propylene glycol monomethyl ether acetate CPN: Cyclopentanone

material

BPFG: Bisphenol fluorene diglycidyl ether (Tokyo Chemical Industry Co., Ltd.)

BNFG: 9,9-bis(6-glycidyloxy-2-naphthyl)fluorene: A compound obtained by synthesis according to Comparative Example 1 of JP2009-155256A

HNCA: 3-hydroxy-2-naphthoic acid (Tokyo Chemical Industry Co., Ltd.)

BNFGA: 9,9-bis(6-glycidyloxy-2-naphthylfluorene acrylic acid adduct: a compound obtained by synthesis according to the description in Japanese Patent No. 6175259

BPDA: Biphenyltetracarboxylic dianhydride (Tokyo Chemical Industry Co., Ltd.)

BT100: 1,2,3,4-butanetetracarboxylic dianhydride (Rikacid BT-100, manufactured by New Japan Chemical Co., Ltd.)

Synthesis Example 1
In a 100mL three-neck flask equipped with a reflux condenser and a thermometer, 10.0g (21.6mmol) of BPFG, 8.14g (43.3mmol) of HNCA, 0.909g (0.432mmol) of tetraethylammonium bromide and 20mL of PGMEA were added and reacted at 130°C for 4 hours. The reaction solution was allowed to cool to room temperature, and the target PGMEA solution was obtained with a solid content concentration of 44.2%. In a 100mL three-neck flask equipped with a reflux condenser and a thermometer, 30g (15.8mmol) of the above reaction solution and 2.58g (8.78mmol) of BPDA were added and reacted at 110°C for 4 hours. The reaction solution was allowed to cool to room temperature, and a light brown solution containing the target product with a weight average molecular weight of 2,800 was obtained (1P-1).

Synthesis Examples 2 and 3
In the same manner as in Synthesis Example 1, polymers (1P-2) to (1P-3) were obtained having the compositions shown in Table 1.

Comparative Synthesis Example 1
7.07 g (10 mmol) of BNFGA, 4.7 g of PGMEA, (3-1), 2.22 g (15 mmol) of phthalic anhydride, 10 mg of 4-methoxyphenol, and 0.52 g (0.1 mmol) of triphenylphosphine were added to a 100 mL three-neck flask equipped with a reflux condenser and a thermometer, and the mixture was reacted at 120° C. for 2 hours and at 70° C. for 6 hours. As a result, a light brown solution containing a compound having a Mw of 1,100 (referred to as (R-1)) was obtained.

Comparative Synthesis Example 2
A polymer was synthesized in the same manner as in Production Example 7 of JP-T 2020-537184 (this polymer is designated as (R-2)).

2. Preparation of Radiation-Sensitive Composition [B] Photopolymerization initiator, [C] Polymerizable compound, and [E] Solvent used in the preparation of the radiation-sensitive composition are shown below.

[B] Photopolymerization initiator B-1: 1,2-octanedione-1-[4-(phenylthio)-2-(O-benzoyloxime)] (Irgacure OXE01, manufactured by BASF)
B-2: 2-methyl-1-(4-methylthiophenyl)-2-morpholinopropan-1-one (Irgacure 907, manufactured by BASF)
B-3: Phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide B-4: 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butanone

[C] Polymerizable compound C-1: 2-hydroxy-3-phenoxypropyl acrylate C-2: bisphenol A ethoxylate diacrylate C-3: phenoxybenzyl acrylate C-4: pentaerythritol tetraacrylate C-5: dipentaerythritol hexaacrylate C-6: tris(2-acryloyloxyethyl) isocyanurate

[E] Solvent E-1: Propylene glycol monomethyl ether acetate (PGMEA)
E-2: Cyclopentanone (CPN)

Example 1
A solution containing 100 parts by mass (solid content) of (1P-1) as a compound [A], 5 parts by mass of (B-1) as a photopolymerization initiator [B], 5 parts by mass of (C-1) and 10 parts by mass of (C-5) as polymerizable compounds [C], 0.5 parts by mass of an adhesion promoter (3-glycidyloxypropyltrimethoxysilane), and 0.2 parts by mass of a surfactant (NEOS Corporation's "FTX-218") were mixed, and then (E-1) as a solvent [E] was added so that the solid content concentration became 35%, followed by stirring to dissolve. The mixture was then filtered through a membrane filter having a pore size of 0.2 μm to prepare the radiation-sensitive composition of Example 1.

(Examples 2 to 8, Comparative Examples 1 to 3)
A radiation-sensitive composition was prepared in the same manner as in Example 1, except that the materials and amounts used were changed as shown in Table 2.

The properties of the radiation-sensitive compositions prepared in Examples 1 to 8 and Comparative Examples 1 to 3 were evaluated as follows. The evaluation results are shown in Table 2.

[Evaluation of refractive index]
The radiation-sensitive composition was applied onto an alkali-free glass substrate using a spinner, and then prebaked on a hot plate at 85° C. for 2 minutes to form a coating film with a thickness of 9.0 μm. The coating film thus obtained was then irradiated with radiation at an exposure dose of 400 mJ/cm ² using a high-pressure mercury lamp (illuminance at 365 nm: about 500 mW/cm ² ). Thereafter, development was performed for 60 seconds at 25° C. using a puddle method with a 2.38% by mass aqueous solution of tetramethylammonium hydroxide at 23° C. as a developer, and then washing with pure water was performed for 60 seconds, and the substrate was then dried. Then, a cured film was formed by post-baking for 40 minutes in an oven at 100° C. The refractive index of the obtained cured film at 589 nm was measured using a prism coupler, and evaluated according to the following evaluation criteria.

Good (◎): Refractive index ≧1.66
Acceptable (◯): 1.66 > refractive index ≧ 1.64
Poor (x): 1.64 > refractive index

[Evaluation of Patterning Characteristics]
Each radiation-sensitive composition was applied onto an alkali-free glass substrate using a spinner, and then prebaked on a hot plate at 85° C. for 3 minutes to form a coating film with a thickness of 9.0 μm. Next, the resulting coating film was irradiated with radiation through a photomask having a plurality of circular residual patterns with different sizes (1 μm intervals) in the range of 10 to 25 μm in diameter, using a projection exposure device manufactured by SUSS MicroTec (high pressure mercury lamp. Illuminance at 365 nm: about 500 mW/cm ² ) with an exposure amount changed in 50 mJ/cm ² intervals in the range of 200 to 600 mJ/cm ² . Thereafter, development was performed for 60 seconds at 25° C. using a 2.38 mass % tetramethylammonium hydroxide aqueous solution at 23° C. as a developer by a puddle method, and then washed with pure water for 60 seconds. Thereafter, the substrate was dried to form a pattern consisting of a plurality of minute bodies formed by the radiation-sensitive composition on the glass substrate. After development, the substrate was observed under an optical microscope and the patterning characteristics were evaluated according to the following evaluation criteria.

If no residue is found on the board and there is almost no peeling of the pattern, then: "Good"
If slight residue or peeling of the pattern is found on the board: "△"
If residues are found on most of the substrate, or if the pattern has peeled off and very little of it remains on the substrate, then the answer is "X".

[Evaluation of Patterning Margin]
Each radiation-sensitive composition was applied onto an alkali-free glass substrate using a spinner, and then prebaked on a hot plate at 85° C. for 3 minutes to form a coating film with a thickness of 9.0 μm. Next, the coating film obtained was irradiated with radiation through a photomask having a circular pattern with a diameter of 20 μm (10 vertical × 10 horizontal at 60 μm intervals) using a projection exposure device manufactured by SUSS MicroTec (high pressure mercury lamp. Illuminance at 365 nm: about 500 mW/cm ² ) with an exposure amount changed in increments of 50 mJ/cm ² in the range of 200 to 600 mJ/cm ² . Thereafter, development was performed for 60 seconds at 25° C. using a 2.38 mass % tetramethylammonium hydroxide aqueous solution at 23° C. as a developer by a puddle method, followed by washing with pure water for 60 seconds, and then drying the substrate. Next, post-baking was performed for 40 minutes in an oven at 100° C. A pattern consisting of a plurality of minute bodies formed by the radiation-sensitive composition was formed on the glass substrate. The maximum and minimum values of all the patterns obtained were measured using an optical microscope, and the patterning margin was evaluated according to the following evaluation criteria.

Maximum value - minimum value of pattern size ≦ 4 μm: "○"
4 μm < maximum value of pattern size - minimum value ≦ 8 μm: "△"
Maximum value of pattern size - minimum value > 8 μm: "X"
If no pattern is found: "-"

[Evaluation of outgassing]
The radiation-sensitive composition was applied onto an alkali-free glass substrate using a spinner, and then prebaked on a hot plate at 85° C. for 2 minutes to form a coating film with a thickness of 9.0 μm. The coating film thus obtained was then irradiated with radiation at an exposure dose of 400 mJ/cm ² using a high-pressure mercury lamp. Thereafter, development was performed for 60 seconds at 25° C. using a 2.38% by mass aqueous solution of tetramethylammonium hydroxide at 23° C. as a developer by a puddle method, and then washing with pure water was performed for 60 seconds, after which the substrate was dried. Then, a cured film was formed by post-baking for 40 minutes in an oven at 100° C. The glass substrate on which the cured film was formed was cut into 1 cm squares, and 8 μg of octadecane was dropped as an internal standard substance, and the amount of outgassing was analyzed using a purge-trap gas chromatograph mass spectrometer. The extraction condition for outgassing was 100° C. for 20 minutes, and the amount of outgassing was calculated by the following formula using the peak area ratio of the internal standard.

Outgas amount (μg/cm ³ )=(X/Y×8 μg)/Z
(In the formula, X represents the peak area of the target outgassing component, Y represents the peak area of octadecane, and Z represents the volume (cm ³ ) of the cured film.)

[A] When the amount of outgassing of the polymer or the compound derived from its decomposition is less than 1000 μg/cm ³ : “Good”
[A] When the amount of outgassing of the polymer or the compound derived from the decomposition thereof is ≧1000 μg/cm ³ : “×”

Claims (12)

[A] a polymer having a partial structure represented by formula (1),

(In formula (1),
^Ar1 represents an aromatic ring;
^Ar2 represents an aromatic ring or a heterocycle;
R ¹ represents a cyano group, a halogen atom, or a hydrocarbon group;
^R2 represents a hydrocarbon group, an alkoxy group, a cycloalkoxy group, an aryloxy group, an aralkyloxy group, an alkylthio group, a cycloalkylthio group, an arylthio group, an aralkylthio group, an acyl group, a halogen atom, a nitro group, a cyano group, or a substituted amino group;
^R3 represents an alkali-soluble group;
X represents an oxygen atom or a sulfur atom;
^Ar3 represents a tetravalent organic group;
A represents an alkylene group;
k represents an integer of 0 to 4;
l, m, and n each independently represent an integer of 0 or more.
[B] a polymerization initiator,
[C] A radiation-sensitive composition comprising a polymerizable compound. 2. The radiation-sensitive composition according to claim 1, wherein Ar ¹ is a benzene ring or a naphthalene ring. 2. The radiation-sensitive composition according to claim 1, wherein ^Ar2 is a monocyclic aromatic hydrocarbon ring or a condensed polycyclic aromatic hydrocarbon ring. 2. The radiation-sensitive composition according to claim 1, wherein ^R3 is a hydroxyl group. A cured product obtained by curing the radiation-sensitive composition according to claim 1. A step of applying the radiation-sensitive composition according to claim 1 onto a substrate to form a coating film;
exposing a portion of the coating to radiation;
and developing the irradiated coating to form a pattern on the substrate. The method for manufacturing a lens according to claim 6 further comprises the step of heating the pattern to form a lens. The method for manufacturing a lens according to claim 7, wherein the temperature at which the pattern is heated is 100°C or less. A display device comprising the cured product according to claim 5. A solid-state imaging device comprising the cured product according to claim 5. An imaging device comprising the solid-state imaging element according to claim 10. A polymer having a partial structure represented by formula (1).

(In formula (1),
^Ar1 represents an aromatic ring;
^Ar2 represents an aromatic ring or a heterocycle;
R ¹ represents a cyano group, a halogen atom, or a hydrocarbon group;
^R2 represents a hydrocarbon group, an alkoxy group, a cycloalkoxy group, an aryloxy group, an aralkyloxy group, an alkylthio group, a cycloalkylthio group, an arylthio group, an aralkylthio group, an acyl group, a halogen atom, a nitro group, a cyano group, or a substituted amino group;
^R3 represents an alkali-soluble group;
X represents an oxygen atom or a sulfur atom;
^Ar3 represents a tetravalent organic group;
A represents an alkylene group;
k represents an integer of 0 to 4;
l, m, and n each independently represent an integer of 0 or more.